The subject of the invention is a new method for monitoring of the level of amino acids in biological material in which the following stages of the analysis of amino acids level in the material may be distinguished: preparation of the biological sample for the chromatographic analysis, separation by liquid chromatography coupled with tandem mass spectrometry, separation of 21 amino acids is carried out through hydro- philic interaction chromatography (HILIC) with the use of columns packed with polar sorbents. Application of the abovementioned method in order to determine the level of amino acids in biological material obtained from subjects with selected type of leukaemia and/or with type 1 diabetes is also the topic of the invention.

The term leukaemia refers to cancer of the haematopoietic system. Correct haematopoiesis is disturbed through a genetic mutation which stops the production of mature and functional cells of the circulatory system in the described disease. Non- differentiated cells infiltrate bone marrow and other tissues of the organism and begin to appear in peripheral blood.

Classification of leukaemia in children is based on a dominant cell line, and on a degree of differentiation of these cells. Consequently, the terms myeloid leukaemia and lymphoblastic leukaemia refers to the cell types involved in the development and progression of particular cancers.

Cancer is one of the more frequent causes of death among children. It is estimated that around 1200 people in Poland develop this disease each year. Approximately 20% of all cancers occurring in children are leukaemias. They usually occur between the age of 2 and 7, more often in males. Cancerous lesions affect white blood cells. The ethiology of the disease has not yet been fully explored. It is assumed that the appearance of cancer is a result of several factors. The genetic background is considered to be the crucial one. Congenital chromosome disorders such as Down syndrome, Klinefelter syndrome, Fanconi syndrome, Shwachman-Diamond syndrome, Bloom syndrome, and Nijmegen breakage syndrome increase the risk of leukaemia occurrence, e.g. Down syndrome increases the risk by 10-20%. Environmental factors, especially exposure to benzene, chlorine derivatives of hydrocarbons, and ionising radiation, may cause the activation of a cascade of oncogenes and thus contribute to the process of carcinogenesis. Several types and subtypes of leukaemia can be differentiated. As far as the course of disease is concerned, two basic groups can be distinguished: acute and chronic leukaemias. If a location of changes is considered as the criterion - leukemias can be divided into myeloid and lymphoblasticones.

Acute lymphoblastic leukaemia (ALL) which constitutes 80% of all leukaemias is the most frequent leukaemia occurring in children.

Treatment of acute lymphoblastic leukaemia is based on chemotherapy - the following stages can be differentiated: remission induction, remission consolidation, and maintenance treatment. In the initial phase of treatment vincristine and daunorubi- cin are applied once a week. Additionally, L-asparaginase, prednisolone, cyclophosphamide, and cytosine arabinoside are also administered. Methotrexate is delivered intrathecally for prevention of the CNS (central nervous system). In the subsequent phase of treatment cyclophosphamide, etoposide, and methotrexate are used. During the maintenance treatment a patient is given methotrexate, and 6-mercaptopurine. In addition to that, every few weeks vincristine, anthracycline, and prednisolone are given for re-induction purpose. Properly selected chemotherapy constitutes a 70% chance of recovery.

In children, the acute non-lymphoblastic leukaemia such as acute myeloid leukaemia (AML) is diagnosed less frequently, - constituting only 15% of all acute leukaemias. This type of cancer is more often characterised with extrameduUary structures infiltration, such as the central nervous system, and bones.

Treatment of acute myeloid leukaemia is also composed of several stages, and ends with success in 43% of cases of disease. At first, daunorubicin, and cytarabine are used often in combination with idarubicin. Methotrexate is delivered intrathecally for prevention of the CNS. In the subsequent stages of treatment cytosine arabinoside, methotrexate, daunorubicin, and tioguanine are applied. Additionally, transplantation of haematopoietic cells (which gives 45-60% chance of recovery) is applied. Only chronic myeloid leukaemia occurs in children. It constitutes less than 5% of leukaemias diagnosed in this age group. Its diagnosis is based on blood testing in which hyperleukocytosis, and anemia are confirmed.

Changes in the composition of cerebrospinal fluid may help to diagnose some diseases.

Examination of changes in the level of amino acids in cerebrospinal fluid obtained from children with acute lymphoblastic leukaemia is significant as it may allow identification of potential response to treatment markers. The results of research shows that the level of glutamine in cerebrospinal fluid of children suffering from cancer was significantlyhigher at the moment of diagnosis than in the control group. A decreasing level of this amino acid was also observed during treatment.

The basis of leukaemia classification is the assumption that leukaemia cells are the population of cells which has stopped at a certain stage of maturation and differenti- ation.Based on the origin of "damaged" cells from the haematopoietic type of cell , acute lekaemias are divided into lymphoblastic (ALL), and myeloid (AML). Acute lymphoblastic leukaemia is a heterogeneous disease. At this stage, according to FAB classification, taking into consideration morphotic criteria dependent on the size of a cell, the shape of a nucleus, and the content of the cytoplasm, the following forms can be differentiated: LI, L2, L3. Contemporary diagnostics of acute leukaemias comprises not only morphological evaluation of marrow's and peripheral blood's blast cells but also cytochemical and cytogenetic examination, and indication of the immunopheno- type of these cells. Phenotypic classification is based on known stages of maturation and phenotypic differentiation of the cells of lymphocyte B or T. In our project we examined children diagnosed with acute leukaemia derived from line B lymphocyte.

In the publication by L. Konieczna et al. entitled: "Hydrophilic interaction chromatography combined with dispersive liquid-liquid micro extraction as a preconcen- tration tool for the simultaneous determination of the panel of underivatized neurotransmitters in human urine samples" J. Chromatogr. A, 1431 (2016) 111-112, and Konieczna et al. entitled: "Analytical approach to determining human biogenic amines and their metabolites using eVol micro extraction in packed syringe coupled to liquid chromatography mass spectrometry method with hydrophilic interaction chromatography column", Talanta 1 (2016) 331-9 (DOI: 1016/j.talanta.2015.12.056) the analysis of neurotransmitters and their metabolites in human blood plasma, and urine has been revealed in which a method based on clean standards of above mentioned analytes was developed. However, those are different compounds in relation to the compounds that are the subject of analysis in this invention.

In this invention other precursor ions characteristic for determined amino acids are monitored based on the mass spectrum received from the analysis of reference substances byLC-MS method in positive ions mode.

Application of a connected techniques - liquid chromatography with mass spectrometry - allows an additional identification of analytes not only by the retention time but also by the mass spectrum where chosen ions (in this case precursor ions [M+H] +) are monitored. Another gradient program, time of gradient, total analysis time, and, most importantly, other ions were monitored during the chromatographic process, and with different values of fragmentation tension.

In case of neurotransmitters and their metabolites, preparation of the sample for the chromatographic analysis involves optimization, and application of microextraction techniques: dispersive liquid-liquid microextraction, and solid-phase extraction packed in the eVol syringe's needle. Microextraction techniques described in detail in the above-mentioned publications have allowed for a successful isolation of these compounds from the biological matrix.

On the other hand???, the preparation of the sample is completely different - much simpler and cheaper in the presented invention. It consist of deproteinization of cerebrospinal fluid by using 0.1 M of HC1, centrifugation, and evaporation of the layer from the precipitate in vacuum conditions. For the analysis of the plasma, 0.1 M of HC1 was used with the purpose of deproteinization. Next, it was extracted by liquid-liquid method with methanol, which was then evaporated under vacuum conditions.

The purpose of this invention is to provide a new way that can be used to detect cancer, acute lymphoblastic leukaemia through determination of amino acids level. The presented method can be also used to detect type 1 diabetes. Surprisingly, the problem has been solved to a significant degree in this invention. The subject of this invention is a new method for monitoring of amino acids level in biological material where the analysis of amino acids in the material proceeds in following stages:

- sample preparation method of the biological material prior to chromatographic analysis,

- chromatographic separation was carried out by liquid chromatography coupled with tandem mass spectrometry,

- separation of 21 amino acids was carried out by hydrophilic interaction chromatography HILIC using columns packed with polar sorbent, ,

- mobile phasewas composed of : phase A) 10 mM ammonium formate (pH3) in water, and phase B) 10 mM ammonium formate in acetonitrile under the conditions of gradient elution,

- Flow rate of the mobile phase was 0.8 - 1 ml/minute,

- column temperature: 25°C

- temperature of the drying gas was in the range from 250 to350°C, flow rate of the drying gas was from 8 to 12 L/minute, in the analysis temperature of the drying gas (nitrogen) was: 350°C, flow rate of the drying gas (nitrogen) was 11 L/minute, collision energy dependent on the monitored product ion (range: from 5 to 70)

- total time of a single analysis of 21 amino acids including column equilibration was 25-30 minutes

- separation of amino acids was carried out under the conditions of gradient elution.

A method in which the sample of biological material was prepared in the following stages:

- internal standard was added: norvaline and homoarginine, labeled(deuterated) leucine, Leu-d3 for the condensation sample of the exhaled breath by volume of lmL

- deproteinization reagent was added: 0,1 M of hydrochloric acid dissolved in water for cerebrospinal fluid or 0,1 M of hydrochloric acid dissolved in methanol for plasma - centrifugation rate: 1000 rpm / 8 minutes

- the sample is collected and it undergoes a process of evaporation in the temperature of 45-60°C/lh until it is dry,

- the dry remains are dissolved in 100 of a mixture of acetonitrile and H ₂ 0 in proportion 8:2 (v/v)

- re-centrifugation rate: 1000 rpm / 8 minutes

- chromatographic analysis using tandem mass detector

The method in which the biological material are: cerebrospinal fluid, blood plasma, exhaled breath condensate samples.

Application of the method defined above for determination of amino acids in subjects suffering from lymphoblastic leukaemia and/or type 1 diabetes.

Application in which the determination is made at the time of diagnosis, and during chemotherapy.

Application in which the diseased subjects are part of the paediatric population.

An advantage of this invention is the easily obtainable biological material, exhausts in particular, and a very simple way of carrying out the analysis.

Biological material such as blood or urine is applied with success in medical diagnosis. However, in practice the exhaled breath condensate (EBC) has been the least used biological material to date. This is probably because it is the least explored one.

Exhaled breath condensates are extremely valuable biological material, which are collected in an entirely non-invasive and safe manner that is not stressful to patient in any way, because they are collected during standard breathing.

It is not only the patients that benefit from this non-invasive (thus, stressless) method of sample colleting, but also analysts and diagnosticians gain as the samples they examine do not require special and time-consuming preparation for their further chromatographic analysis. The exhaled breath condensate is relatively free of proteins, therefore it does not require to undergo the deproteinisation stage, which is an essential procedure with blood plasma, and cerebrospinal fluid. For this reason, preparation of the EBC sample is based on evaporation of the sample under vacuum, that is on its "concentration", which makes this method more economical as it saves analyst's time.

Moreover, the research performed by the creators indicated that the results of the analysis of the influence of EBC (sample) solution's pH used for administrating ana- lytes into chromatographic system suggest the possibility of their analysis without prior pH change (which is necessary with urine samples collected non-invasively).

The terms used above, and in the description and patent claims, have following meaning:

Amino acids - stands for 21 amino acids: Alanine (Ala), Arginine (Arg), Asparagine (Asn), Aspartic Acid (Asp), Cysteine (Cys), Glycine (Gly), Glutamine (Gin), Glutamine Acid (Glu), Histidine (His), Hydroxyproline (Hpro), Isoleucine (He), Leucine (Leu), Lysine (Lys), Methionine (Met), Phenylalanine (Phe), Proline (Pro), Serine (Ser), Threonine (Thr), Tryptophan (Trp), Tyrosine (Tyr), Valine (Val).

Exhaled breath condensate - stands for the sample of exhaled breath, which is then concentrated through its evaporation under vacuum accordingly to this invention.

Description of figures and tables:

Fig. 1 - presents average values of amino acids' concentration in the cerebrospinal fluid determined using LC-MS method; n = 40 subjects (children) a) all of the measured amino acids, b) Gin, and Hpro c) amino acids: Ala, Asn, Arg, Glu, His, Leu, Liz, Pro, Ser, Thr, Tyr, Val, excluding Gin, and Hpro d) remaining amino acids excluding the ones mentioned in point b and c. Standard deviation is visually represented in Figs a-d, and statistically significant differences between average concentration of amino acid of interest obtained from ALL leukaemia group and from the control group are marked with * and represented in Fig. b-d.

Fig. 2 - presents average values of amino acids concentration in the blood plasma determined using LC-MS method; n = 40 subjects (children) a) all of the measured amino acids, b) Gin, and Hpro c)amino acids: Ala, Asn, Arg, Glu, His, Leu, Liz, Pro, Ser, Thr, Tyr, Val, excluding Gin, and Hpro d) remaining amino acids excluding the ones mentioned in point b and c. Standard deviation is visually represented in Figures a-d, and statistically significant differences between average concentration of a given amino acid in the group of subjects suffering from ALL leukaemia and the control group are marked with * and represented in Figures b-d.

Fig. 3 - presents the scheme of the new procedure of cerebrospinal fluid, and plasma samples preparation for the LC-MS analysis.

Fig. 4a - presents average values of amino acids concentration in the exhaled breath condensates determined using LC-MS/MS method; n = 6 subjects (children) for all of the measured amino acids in the group of children suffering for leukaemia ALL in the moment of diagnosis (before treatment, n=6), and in the group of subjects with disease remission (33 day of treatment, n = 6). Statistically significant differences between average concentration of a given amino acid in the group of subjects suffering from leukaemia ALL at the time of diagnosis (before treatment) and the group with disease remission (33 day of treatment) are marked with * in Figure 4a.

Fig. 4b - presents average values of amino acids concentration in the exhaled breath condensates determined using LC-MS/Ms method; n = 6 subjects (children) for all of the measured amino acids in the group of children suffering for leukaemia ALL at the time of diagnosis (before treatment, n=6), and in the group of healthy subjects (n = 10). Statistically significant differences between average concentration of a given amino acid in the group of subjects suffering from leukaemia ALL at the time of diagnosis (before treatment, day 0) and the group of healthy subjects (n = 10) are marked with * in Figure 4b.

Fig. 5 - presents the chromatogram of standards for the analysed amino acids determined using LC-MS/MS method.

Fig. 6 - presents the chromatograms of 23 analysed amino acids, and the internal standard (Leucine-d3) in the exhaled breath condensates collected by using CL-MS/MS technique in positive ions mode: from a child with diagnosed leukaemia (A), from a child with disease remission (B), and from a healthy child (C), where: 1 - Tryptophan, 2 - Phenylalanine, 3 - Leucine-D3, 4 - Leucine, 5 - Isoleucine, 6 - Methionine, 7 - Nor- valine, 8 - Tyrosine, 9 - Valine, 10 - Proline, 11 - Cysteine, 12 - Hydroxyproline, 13 - Alanine, 14 - Serine, 15 - Threonine, 16 - Glycine, 17 - Glutamine Acid, 18 - Gluta- mine, 19 - Asparagine, 20 - Aspartic Acid, 21 - Histidine, 22 - Homoarginine, 23 - Arginine, 24 - Lysine.

Fig. 7 - presents the chromatograms of the 23 analysed amino acids, and the internal standard (Leucine-d3) in the exhaled breath condensates collected by using CL-MS/MS technique in positive ions mode: from a patient with type I diabetes (A), from a healthy child (B), where: 1 - Tryptophan, 2 - Phenylalanine, 3 - Leucine-D3, 4 - Leucine, 5 - Isoleucine, 6 - Methionine, 7 - Norvaline, 8 - Tyrosine, 9 - Valine, 10 - Proline, 11 - Cysteine, 12 - Hydroxyproline, 13 - Alanine, 14 - Serine, 15 - Threonine, 16 - Glycine, 17 - Glutamine Acid, 18 - Glutamine, 19 - Asparagine, 20 - Aspartic Acid, 21 - Histidine, 22 - Homoarginine, 23 - Arginine, 24 - Lysine.

Fig. 8 - presents the scheme of the new procedure of exhaled breath samples preparation for the LC-MS/MS analysis.

The following examples of performance illustrate the invention, while, not restricting it.

a) L-amino acids in cerebrospinal fluid and in human blood plasma in the group of diseased children and in the control group were the subject matter of the research.

Example 1

Analysis conditions

The analysis of amino acids was carried out using liquid chromatography coupled with mass spectrometry (LC-MS) with the ChemStation data acquisition system (Agilent Technologies, Santa Clara, CA, USA). The HPLC system was equipped with a pump, an autosampler, a UV detector, and a degasser. Chromatographic separation of amino acids was done on the basis of hydrophilic interaction liquid chromatography HILIC using the Xbridge Amide column with dimension of 3x100 mm, 3,5 μπι (Waters) packed with polar sorbent which was placed in a thermostat at the temperature of 25°C. Mobile phase consisted of the phase A: 10 mM ammonium formate (pH3) in water, and B: 10 mM ammonium formate in acetonitrile under the conditions of gradient elution. Flow rate of the mobile phase was 1 ml/minute. The working conditions of the mass detector were as follows: temperature of the drying gas (nitrogen): 250°C, flow rate of the drying gas (nitrogen): 12 L/minute, capillary voltage: 3kV, fragmentation voltage dependent on the substance (range from 75 to 125V). The total time of a single analysis of 21 amino acids including column equilibration was 30 minutes. The separation of amino acids was carried out under the conditions of gradient elution.

Preparation of biological samples for the LC-MS analysis

A new sample preparation procedure prior to the chromatographic analysis based on liquid- liquid extraction (LLE) using 0,1 M HC1 for cerebrospinal fluid, and 0,1 M HC1 in methanol for plasma sample was developed.

A new method of sample preparation for the chromatographic analysis using LC-MS technique (which is based on application of 0,1 M of hydrochloric acid as a deproteini- sation element [deproteinisation stage] for cerebrospinal fluid (CSF), and 0,1 hydrochloric acid in methanol for plasma) was developed. The choice of the deproteinization element resulted from the difference in the total number of proteins the number of which is much larger in plasma samples. Hydrochloric acid serves both as the deproteinisation element, and as the solvent. This is why the preparation stage was based on the single-stage liquid-liquid extraction. As a result of using 0,1 M of HC1, the roughage proteins precipitated, and the amino acids of interest remained in the aqueous layer for cerebrospinal fluid where the following stage was to evaporate the sample until it is dry and then dissolve it in the mixture of acetonitrile and H ₂ 0 (8:2, v/v). In the case of plasma, 0,1 M of hydrochloric acid in methanol was used, where after proteins' precipitation the organic layer was moved to new samples, and was evaporated under vacuum until it was dry similarly to CSF (cerebrospinal fluid) samples. This new procedure of sample preparation allowed successful extraction of examined amino acids. Detailed process of the applied procedure is presented in Fig. 3.

Examined subjects

The subjects of examination were paediatric patients (in the number of 40) from the Department of Pediatrics, Hematology and Oncology (Medical University of Gdansk, Poland) , diagnosed with B-cell acute lymphoblastic leukaemia (BCP-ALL). L- asparaginase is one of the medications used in treatment of these patients in accordance with the 1 A protocol. It influences amino acid management in various body fluids (cerebrospinal fluid, blood, urine) before, and during treatment. The levels of certain L- amino acids indicate statistically significant differences in particular stages of therapy when compared with the control group. An attempt to demonstrate the correlation between the level of chosen amino acids at the moment of diagnosis and during chemotherapy was made.

Results

Final diagnosis of leukaemia is based on the results of cerebrospinal fluid test, collected by means of lumbar puncture. This procedure is invasive and uncongenial for a patient, and because of this new biomarkers that would allow an evaluation of effectiveness of the treatment and prospects of recovering are still being searched for. Contemporary medicine is attempting to individualie therapies. Paediatric patient is especially vulnerable to negative effects of the applied treatment because cytostatic medicines interfere with the development of the organism. Personalized medicine strives towards the situation in which patients who react positively to treatment would not get unnecessarily large doses of chemotherapeutics, while the treatment of patients with worse prospects of recovering should be more invasive in justified cases.

Table 1 - presents average values of amino acids' densities in cerebrospinal fluid of children with diagnosed acute lymphoblastic leukemia (ALL) (n = 40 people / children /) and in the clinical control group (n = 6), marked by the LC-MS method, 0th day means the moment of diagnosis of the disease before starting treatment, 15th day means a stage after chemotherapy treatment, 33rd day means remission of the disease.

Table 1

O day 15th day 33rd day Control

AA μg/ml ± SD jig/ml ± SD μg/ml ± SD μ^πιΐ ± SD

1 Ala 19.120 16.331 9.020 4.917 15.960 11.821 15.682 9.093

2 Arg 16.290 4.963 10.391 5.232 21.886 11.746 31.950 8.881

3 Asn 1.141 0.385 2.350 0.401 3.420 0.819 3.440 1.000 4 Asp 0.901 0.322 0.578 0.225 1.192 0.322 1.710 0.208

5 Gin 603.700 139.626 270.273 62.170 201.489 46.825 87.499 28.275

6 Glu 4.241 2.069 5.480 1.878 6.184 3.220 6.911 1.794

7 Gly 0.270 0.172 0.196 0.157 0.178 0.099 0.170 0.074

8 His 13.870 3.417 24.374 10.155 28.766 8.284 29.800 8.049

9 Hpro 387.060 73.962 103.710 37.626 64.110 22.943 56.240 14.385

10 He 0.230 0.144 0.160 0.199 0.150 0.106 0.130 0.063

11 Leu 1.800 0.189 1.500 0.197 1.400 0.217 1.300 0.181

12 Lys 12.342 5.761 13.463 7.246 15.084 6.131 15.872 10.993

13 Phe 0.510 0.238 0.310 0.119 0.270 0.094 0.267 0.123

14 Pro 10.021 0.930 3.845 0.501 3.027 0.411 2.987 0.176

15 Ser 4.210 0.667 3.021 1.098 2.337 1.274 2.670 0.828

16 Thr 7.091 0.560 4.211 1.543 3.061 0.420 13.570 0.880

17 Trp 0.090 0.015 0.070 0.013 0.060 0.010 0.050 0.013

18 Tyr 2.050 0.617 3.540 0.623 3.851 1.934 4.110 1.101

19 Val 4.650 0.693 6.765 1.149 7.024 0.808 14.498 3.958

Table 2 - presents average values of amino acids' densities in plasma of children with diagnosed acute lymphoblastic leukemia (ALL) (n = 40 people / children) and in the clinical control group (n = 6), marked by the LC-MS method, 0 day means the moment of diagnosis of the disease before starting treatment, 15th day means a stage after chemotherapy treatment, 33rd day means remission of the disease.

Tabela 2

0th day 15th day 33rd day Control

AA μg/ml ± SD μg/ml ± SD μg/ml ± SD μ&ΊηΙ ± SD

1 Ala 166,130 29,296 147,531 25,198 119,071 28,363 121,072 47,791

2 Arg 147,680 22,881 102,490 17,827 145,310 29,048 159,510 61,213

3 Asn 11,658 4,181 23,504 4,713 34,529 9,692 34,462 8,050

4 Asp 3,020 0,586 4,697 1,831 7,590 2,049 7,680 1,507

5 Gin 472,205 92,365 129,030 29,228 57,418 13,446 56,008 14,338

6 Glu 27,480 7,412 20,684 4,108 11,378 2,268 11,378 2,268

7 Gly 21,764 10,647 13,927 4,703 12,585 6,999 12,179 3,967

8 His 26,160 4,531 15,234 6,347 14,283 4,139 13,646 4,505

9 Hpro 261,320 49,592 323,575 117,393 356,442 91,770 375,144 104,240

10 lie 2,850 1,679 1,595 1,189 1,788 1,078 1,764 0,591

11 Leu 16,529 2,453 11,084 2,054 10,497 1,882 9,889 0,912

12 Lys 20,871 8,447 26,926 14,493 29,866 12,140 28,296 9,070

13 Phe 50,111 21,324 33,773 9,854 34,770 8,863 36,423 10,920

14 Pro 23,328 1,237 13,550 1,870 8,359 1,089 6,659 1,728

15 Ser 9,317 1,427 12,083 4,391 12,614 6,879 13,712 3,369 16 Thr 14,975 2,010 23,285 8,475 30,855 4,235 30,968 7,350

17 Trp 11,216 2,113 16,467 3,779 17,441 2,006 21,940 9,422

18 Tyr 9,259 2,786 16,993 3,076 17,985 7,977 18,202 4,359

19 Val 9,350 1,621 23,000 3,906 28,094 3,234 29,811 8,599 b) The subject of the research were L-amino acids in exhaled breath condensate in the group of diseased children and the clinical control group.

Example 2

Conditions of the analysis

Analysis of amino acid in exhaled breath condensate samples was performed by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) with MassHunter data acquisition system (Agilent Technologies, Santa Clara, CA, USA). The HPLC system was equipped with a pump, autosampler, UV detector, and degasser. Chromatographic separation of amino acids was conducted on the basis of hydrophilic interaction chromatography (HILIC) using a XBridge Amide column, size 3 x 100 mm, 3.5 μηι (Waters), which was placed in a thermostat at 25°C temperature. The mobile phase consisted of phase A: 10 mM ammonium formate (pH3) in water, and B: 10 mM ammonium formate in acetonitrile under gradient elution conditions. The flow of mobile phase was 0.8 mL/min. Column temperature was 25°C. The working conditions of the mass detector were as follows: temperature of the drying gas (nitrogen): 350°C, flow of the drying gas (nitrogen): 8 L/min, temperature of the sheath gas (nitrogen): 350°C, flow of the sheath gas (nitrogen): 11 L/rnin, collision energy depending on the monitored daughter ion (range from 5 to 70). The duration of a single analysis of 21 amino acids together with column equilibration is 25 minutes. Separation of amino acids occurred under gradient elution conditions. Under selected, optimized and above- described conditions, a chromatogram of the standards of the analyzed amino acids was obtained, as illustrated in Fig. 2. Preparation of biological samples for the LC-MS/MS analysis

A fast, simple and solvent-free procedure for sample preparation for chromatographic analysis was developed, which is based on condensation of a sample of exhaled breath condensate by its evaporation under vacuum conditions (exhaled breath condensate). Due to the very low levels of amino acid concentrations in exhaled breath condensates, a new procedure for sample preparation has been developed before further analysis, using liquid chromatography technique coupled with tandem mass spectrometry (LC- MS/MS), which involves evaporation of the sample under vacuum conditions using concentrator CentriVap (LabConco, (batch number 121168609). The stages consist of adding an internal standard: labeled leucine, Leu-d3, to the sample of exhaled breath condensate of a volume of lmL, rotation: 1000 rpm/8 minutes. The sample is then taken and evaporated to dryness at 60°C temperature duringlh. The next step involves dissolving the dry residue in 100 of a water-acetonitrile mixture (8: 2, v/v) and again rotating 10000 rpm/8 minutes followed by LC-MS/MS analysis. The detailed course of the aforesaid procedure is presented in Fig. 4.

This choice of sample preparation procedure resulted from the fact that the exhaled breath condensate is virtually free from proteins and does not require the use of a deproteinizing reagent. The new method of sample preparation for analysis allowed concentration of the sample, which translated into increase of sensitivity of the method, and then enabled effective further analysis of the tested amino acids with the use of LC- MS/MS technique (Fig. 4.)

Subjects

6 pediatric patients of the Department of Pediatrics, Hematology and Oncology in Gdansk, with diagnosed B-cell precursor acute lymphoblastic leukemia (BCP-ALL) were subjects to the study. One of the drugs used to treat these patients according to protocol 1 A is L- asparaginase, which affects the amino acid balance in human body. We present the results of tests based on comparing the concentrations of amino acids in exhaled breath condensates before and during the treatment (Table 1). Levels of some L-amino acids show statistically significant differences at individual stages of the therapy (Fig. la illustrates the moment of diagnosis in relation to the remission stage of the disease) and Fig. lb presents the moment of diagnosis compared with the clinical control group. An attempt was made to show a correlation between the level of selected amino acids at the time of diagnosis and during chemotherapy.

Results

The final diagnosis of leukemia is based on the results of cerebrospinal fluid, collected by means of a lumbar puncture. Lumbar puncture is an invasive and unpleasant procedure for patients, therefore new biomarkers are still being sought, which would allow to evaluate the effectiveness of the therapy and estimate the prognosis. Modern medicine aims to use non-invasive, non-painful methods of sampling for testing, as well as individualizing therapy. A pediatric patient is particularly exposed to the negative effects of the treatment, because cytostatic drugs interfere with the development of the young body. The goal of personalized medicine is to lead to the situation that patients who respond well to treatment would not receive unnecessarily high doses of chemotherapeutics. However, treatment in case of patients who have worse prognosis should be more aggressive in justified cases. Table 1 shows the average concentration values determined using the developed LC-MS/MS method at the time of diagnosis (0 ^th day, n = 6), during remission of the disease (33 ^rd day, n = 6) and in the group of healthy children (n = 10).

Table 1 - presents average values of amino acid concentrations in exhaled breath condensates of children with diagnosed acute lymphoblastic leukemia ALL (n = 6 subjects/children) at the time of diagnosis, during remission of the disease and in the clinical control group (n = 10), determined by LC-MS / MS method, 0 day means the moment of diagnosis of the disease before starting the treatment, 33 ^rd day means remission of the disease. Table 1

Graphically represented levels of labeled amino acids in the groups of subjects: in the group of patients at the time of diagnosis of leukaemia (0 day, n = 6) and during disease remission (33rd day, n = 6) they are presented in the form of a bar graph in Fig. la. Fig. lb, on the other hand, shows average values of amino acid concentrations in exhaled breath condensates of patients before the treatment (diagnosis, 0 day) and of clinical control group of healthy control paediatric group (n = 10).

Obtained records of the test apparatus in the form of chromatographic peaks show the chromatograms obtained with the use of LC-MS/MS method: including for the analysed benchmark substances (Fig. 5) and for 23 amino acids in exhaled breath samples collected from a child diagnosed with leukaemia (Fig. 6A), from a child during remission of the disease (Fig. 6B) and from a healthy child (Fig. 6C). Example 3

The basis and purpose of testing of the group of children with type 1 diabetes

In Poland, about 1300 children are diagnosed with cancer every year. In the last few decades, therapeutic results in this group of diseases have definitely improved. This was achieved due to intensive therapeutic protocols, adapted to the prognostic factors present in the patient. However, there is still a group of patients whose final therapeutic effect are far from satisfactory.

The main goal (long-term effect) is to improve the metabolic control of patients with type 1 diabetes and reduce the incidence of acute and chronic complications of diabetes.

The direct and immediate goal is to detect metabolic abnormalities in children with type 1 diabetes. It is highly probable that an additional benefit of the newly developed noninvasive method for amino acid level marking in exhaled breath condensates will be the possibility of earlier detection of metabolic changes that may predispose to acute complications of type 1 diabetes such as metabolic acidosis and hypoglycaemia. Undoubtedly, our study will also contribute to earlier detection of metabolic changes in patients with type 1 diabetes, which may predispose to the development of chronic complications, including micro and macroangiopathy.

The result of the project will be the development of a new research method allowing for non-invasive diagnostics of metabolic changes occurring in type 1 diabetes, which may contribute to early detection of the disease and monitoring of patients already suffering from acute and chronic complications, as well as monitoring complications of intensive insulin therapy - by means of mass spectrometry.

The test evaluated the exhaled breath condensation taken at specific time points:

Type 1 diabetes:

1. Evaluation after a stabilized one-year treatment.

2. Evaluation during control visits.

3. Evaluation of the occurrence of acute or chronic complications and the stage of causative treatment.

4. Before and after the possible change of treatment. EBC (Exhaled breath condensate) was collected in accordance with the diagnostic protocol and will not burden the patient with any additional procedure except the additional measurement of blood glucose level with a glucose meter before and after the test.

The proposed new technique for collecting exhaled breath condensate allows for an unprecedented combination in the diagnostics of leukaemia and type 1 diabetes of organ specificity with total non-invasiveness. First of all, it offers a number of possibilities in the form of multiple, frequent repetition of the test, performing it in the most critical period of time from the clinical point of view (point-of-care real-time analysis), in patients in severe conditions, and what is particularly important to us - in children. During conducting of the measurements, a patient breathes normally and calmly, the measurements do not cause any damage to airway mucosa. The collection of condensates is possible not only among children from the age of three, but even among infants, through the use of special face masks. In addition, as a non-invasive procedure, it can be repeated multiple times, giving the possibility of obtaining disease markers in real time.

The obtained results will enable detection of new risk factors in cancer diseases and type 1 diabetes in children, as well as allowing for the development of new therapeutic strategies, which would be more precisely adapted to the stage or aggressiveness of the disease. Aspects such as early detection of complications of the applied treatment and the disease itself, and immediate inclusion of appropriate treatment are undoubtedly the positive effects that may arise from the study.

Table 2 - presents average values of amino acid concentrations in exhaled breath condensates in children with type 1 diabetes (n = 19 subjects/children) and in the clinical control group (n = 54), determined by the LC-MS/MS method.

Leucine 1.33 0.8890 2.98 0.9862

Isoleucine 0.78 0.6228 1.68 0.7513

Methionine 1.37 0.2931 0.11 0.0030

Norvaline 0.49 0.3055 1.11 0.4297

Valine 4.51 2.2524 3.67 1.1677

Tyrosine 1.44 0.8382 2.46 1.0591

Proline 1.17 0.7892 2.49 0.8779

Alanine 3.34 1.5587 7.21 3.4095

Hydroxyproline 0.81 0.1668 0.80 0.0941

Threonine 1.99 0.9707 3.90 1.5489

Glycine 3.93 1.9350 11.57 5.1694

Glutamine 0.58 0.1927 0.62 0.1864

Serine 17.,81 76.0134 70.65 34.6106

Asparagine 1.00 0.4751 1.16 0.5726

Glutamic acid 0.98 0.3738 1.59 0.7781

Aspartic acid 7.34 3.6776 7.27 3.3787

Homoarginine 0.51 0.1608 0.60 0.2082

Histidine 1.09 0.5007 4.10 2.0094

Arginine 0.55 0.2417 1.32 0.6609

Lysine 2.43 1.2180 3.45 1.71830

Obtained records of the test apparatus in the form of chromatographic peaks show the chromatograms obtained by the LC-MS/MS technique: including for the analyzed benchmark substances (Figure 5) and for 23 amino acids in exhaled breath samples from a child with type 1 diabetes (Fig 7A) and a healthy child (Figure 7B).

Description of the protocol 1 A

Initial diagnosis of acute leukaemia is based in the first place on classic criteria, i.e. interview, physical symptoms and laboratory blood tests. It should be noted that these symptoms are often unclear and non-specific and due to that they can be mistaken with the symptoms of common childhood illnesses which may delay the proper diagnosis. In the next stage, specialized cyto chemical, morphological, cytogenetic tests and immunophenotypification of the collected bone marrow are performed. After diagnosing leukemia on the basis of the performed clinical tests, and determining its type, the clinician chooses the patient's treatment protocol. The acute lymphoblastic leukaemia treatment protocol 1 A (PROTOCOL 1A) is the first protocol that covers the expected treatment time of 33 days. On the same day as the diagnosis is made (after performing the myelogram of bone marrow and lumbar puncture for the assessment of cerebrospinal fluid), the treatment begins. At the beginning, the patient is given a dose of steroids adapted to his/her age and weight, a child receives Encorton for one week, then on the eighth day, the response to steroid therapy is checked. If the response is good, the child remains in the intermediate risk group (the results are visible in the blood smear). On the twelfth day, a lumbar puncture is performed during which methotrexat is administered to the spinal cord. Another important day is the 15th day, in which the myelogram of bone marrow is performed to check if the remission of the disease has been achieved (i.e. a decrease in the number of tumor cells, called blasts, in bone marrow to less than 5% and the withdrawal of clinical symptoms associated with the disease). The therapy ends on the 33rd day, when the lumbar puncture with methotrexate and myelogram are performed. A child should be in complete remission.

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