EFFECT OF IRON ON BONE TISSUE METABOLISM AND THYROID FUNCTION IN CHILDREN LIVING ON RADIOLOGICALLY CONTAMINATED TERRITORIES SINCE THE ChNPP ACCIDENT

OBJECTIVE

identification of clinical and metabolic characteristics of osteogenesis and factors affecting bone mineral density (BMD) in children living in radioactively contaminated territories (RCT) after the ChNPP accident for the use of therapeutic and preventive measures aiming to reduce the incidence of disorders.

MATERIALS AND METHODS

Children aged 4 to 18 years old (n = 539) were involved in the study within 4 age groups, namely under 7 years old, 7-10 years old, 10-14 years old, older than 14 years old. Studied parameters in children with a reduced BMD (85-65 relative units and under 65 relative units) were estimated vs. the normative BMD (100-85 relative units) cases. Diagnosis of osteopenia and osteoporosis in children was established according to the BMD T-index. Family history of the relatives of children was studied. Body weight at birth, fractures of the long bones, complaints of osalgia, jaw anomalies, dental caries, presence of obesity, and hypermobility syndrome (HMS) were assessed. Peripheral blood biochemical tests were performed featuring the serum total protein, alkaline phosphatase (APh), calcium, vitamin D, creatinine, serum iron (SI), ferritin, cortisol, pituitary thyroid-stimulating hormone (TSH), and free thyroxine (FT4) assay. BMD was measured and radiation doses in children were reconstructed.

RESULTS

BMD depended on the age of children. A direct correlation was established between the cholelithiasis and urolithiasis incidence (р < 0.01), cancer and endocrine diseases (р < 0.05) in the relatives of children that had BMD under 65 relative units. Dental caries developed more often (р < 0.05), while obesity was less frequent (р < 0.05) in the subjects with BMD < 65 relative units. A direct correlation was established between the level of serum creatinine and BMD (р < 0.01), and there was an inverse correlation between the serum APh level and BMD (р < 0.001).Every third child had a vitamin D deficiency. Fractures of long bones and increased content of SI and TSH were characteristic for the children having got osteopenia (BMD within 85-65 relative units), while besides a predisposition to bone fractures the higher levels of SI, APh, cortisol both with calcium deficiency were found in children with osteoporosis (BMD < 65 relative units) compared to the general group with a similar BMD. An increased incidence of HMS was characteristic too. Radiation doses in children with osteopenia were higher than in those with osteoporosis: (1.17 ± 0.09) mSv and (0.92 ± 0.06) mSv respectively (р < 0.05). No correlation was found between the radiation doses and clinical signs, blood biochemistry or BMD.

CONCLUSIONS

Study of the functional mechanisms of bone structures in children, depending on their metabolism, had made it possible to reveal the factors that affect bone formation in children living in RCT after the ChNPP accident, and to form the population groups for the timely application of therapeutic and preventive measures aiming to reduce the incidence of disorders of musculoskeletal system.

DRIVERS OF HYPERFERREMIA IN CHILDREN LIVING ON RADIOLOGICALLY CONTAMINATED TERRITORIES AFTER THE CHNPP ACCIDENT IN UKRAINE

OBJECTIVE

assessment of clinical-hematological and metabolic-biochemical parameters of the of bone tissue and hormonal regulation depending on the serum iron content and radiation dose values in children living on radiologically contaminated territories after the ChNPP accident in Ukraine.

MATERIALS AND METHODS

Children (n = 271) living on radiologically contaminated territories (RCT) of Ukraine were involved in the study. Three study groups were formed according to the serum iron level (SIL), namely group I with SIL 10.0-22.0 μmol/l (n = 92), group II with SIL 23.0-34.0 μmol/l (n = 144), and group III with SIL above 35.0 μmol/l (n = 35). Diseases in the family tree, bodyweight at birth, complaints on osalgia, bone fractures, jaw anomalies, dental caries, and obesity were accounted. Morphometric parameters of erythrocytes and hemogram elements were analyzed. Creatinine, alkaline phosphatase, calcium, total protein, iron, cholesterol, bilirubin, and transaminases were assayed in blood serum. The urine content of the 19 free amino acids, serum content of the free thyroxine (FT4), pituitary thyroid-stimulating hormone (TSH), and cortisol were assayed both with bone tissue density. Individual radiation doses were calculated.

RESULTS

In 12.9 % of cases the SIL was > 35.0 μmol/l. Relatives with endocrine diseases were often present in the family tree of children with SIL > 23.0 μmol/l. There were increased urine content of the free amino acids (p < 0.05) and signs of protein degradation under high SIL. Contents of amino acids involved in collagen synthesis and antioxidant status (alanine, serine, glutamine, aspartic acid) and iron metabolism (arginine, leucine) were assayed at the highest levels (p < 0.05). Urinary levels of valine, lysine, and methionine, which are associated with iron metabolism, were decreased (p < 0.05). An inverse correlation (rs = -0.58; p < 0.01) was established between the serum TSH and cortisol levels regardless of the SIL. Serum TSH level directly correlated with urine content of amino acids involved in collagen synthesis. An inverse correlation (rs = -0.55; p < 0.001) was established between the serum TSH level and urine content of tyrosine that is essential for the thyroid hormone (triiodothyronine and thyroxine) synthesis.Cortisol was found having a negative effect on protein synthesis. Inverse correlation was established between the serum cortisol level and urine content of the free amino acids essential for collagen synthesis. There was no dependence of the average radiation dose values on the SIL. An inverse correlation was determined between the patient's radiation dose and SIL > 35.0 μmol/l (rs = -0.29; p < 0.05).

CONCLUSIONS

The increased SIL in children living on RCT may occur due to both a genetic predisposition and the acquired factors driving protein and mineral metabolism of bone and their hormonal regulation.

FACTORS AFFECTING MECHANISMS OF INCREASED BONE DENSITY FORMATION IN CHILDREN LIVING ON RADIOLOGICALLY CONTAMINATED TERRITORIES AFTER THE ChNPP ACCIDENT

OBJECTIVE

to determine the causes of increased bone mineral density (BMD) based on case history, clinical and laboratory data, including the assay of hormones involved in ossification processes in children, living on radiologically contaminated territories (RCT) after the accident at the ChNPP, compared to the normative BMD patterns.

MATERIALS AND METHODS

There were 289 children involved in the study. The 1st group included persons with a BMD above 100 IU, 2nd group - with normative BMD (100-85 IU). Family history of diseases was assessed featuring cancer and endocrine diseases, cholelithiasis, and urolithiasis. Weight of the child at birth, frequency of bone fractures, complaints about osalgia, jaw abnormalities, dental caries, presence or absence of obesity, peripheral blood count, blood biochemical parameters (total protein, creatinine, iron, alkaline phosphatase, calcium), serum pituitary thyroid-stimulating hormone and cortisol were accounted. Children's radiation doses were calculated according to the materials of the «General dosimetric certification of settlements of Ukraine that were exposed to radioactive contamination after the Chornobyl accident».

RESULTS

Higher than normative BMD values were found in children after puberty, while normative ones - in puberty (р < 0.001), regardless of gender. A direct correlation between the bone fractures frequency was established in children with increased BMD (р < 0.01). Jaw anomalies and dental caries occurred at that significantly less often than in normative BMD (р > 0.05). A direct correlation was established between the obesity and BMD (р < 0.001).Increased alkaline phosphatase activity was inversely correlated with BMD (rs = -0.21; р < 0.05). In children with elevated BMD a direct correlation was established between the level of iron and endocrine disorders in the family history (р > 0.001). Serum level of cortisol was directly correlated with dental caries (р < 0.05). In children, regardless of BMD value, a direct correlation was established between the radiation dose, age and obesity (р < 0.001).

CONCLUSIONS

Higher than normative BMD is accompanied by an increased frequency of bone fractures, jaw abnormalities, metabolic changes in bone tissue and bone tissue hormonal regulation in children, which requires application of pathogenetic therapy for the osteogenesis.

EFFECT OF IRON ON BONE TISSUE METABOLISM AND THYROID FUNCTION IN CHILDREN LIVING ON RADIOLOGICALLY CONTAMINATED TERRITORIES SINCE THE ChNPP ACCIDENT

OBJECTIVE

To assess the metabolic processes in bone tissue and state of thyroid gland depending on iron metabolism parameters in children of pre-pubertal, pubertal and post-pubertal age, living on radiologically contaminated territories after the ChNPP accident.

MATERIALS AND METHODS

Children (n = 119) aged 6 to 18 years were examined and the 4 study groups were formed, featuring the childhood, pre-pubertal, pubertal and post-pubertal life periods. Clinical symptoms, iron metabolism parameters (serum iron (SI) and ferritin (SF) content, transferrin saturation coefficient), parameters of bone tissue metabolism (serum creatinine and alkaline phosphatase (APh)), and amino acid content in urine were taken into account. Functional state of thyroid, titers of antibodies to thyroperoxidase (TPOAb) and thyroglobulin (TgAb) were assayed. Results and their discussion are presented depending on the age of children, biochemical parameters of blood, iron metabolism findings, thyroid gland function and individualized radiation doses.

RESULTS

In 13.4 % of pubertal and post-pubertal children an elevated content of SI and SF was observed. APh levels were increased in 20.2 % of children (758.9 ± 16.3 U/l) being directly correlated with SI levels (rs = 0.50; р < 0.01). In 16.3 % of children of pubertal and post-pubertal age, in whom the level of SI was above 27 μmol/l, a direct correlation with serum thyroid-stimulating hormone (TSH) level was established in case of the hormone content above 2.5 mU/l (rs = 0.50; р < 0.05). Serum creatinine level directly correlated with glycine content in urine (rs = 0.70), which is a part of collagen, and inversely correlated with serum APh (rs = -0.47), (р < 0.05). Under the levels of SI higher than (15.1 ± 1.2) μmol/l and SF higher than (87.5 ± 6.4) ng/ml, the TPOAb titer was higher than at lower iron concentrations (U-test = 64.5, р < 0.05). The TgAb titer directly correlated with SI (rs = 0.39) and TSH (rs = 0.81) levels (р < 0.01). The average effective radiation dose in children was (0.75 ± 0.10) mSv. A direct correlation was established between the child's radiation dose and age (rs = 0.33; р < 0.05).

CONCLUSIONS

Bone metabolism depends on the age of children, characteristics of pubertal period, excess of iron in the body, and functional state of thyroid system, which is involved in collagen formation and protein metabolism.

THYROID DISEASE IN THE LATE OBSERVATION PERIOD UPON CHEMO AND RADIOTHERAPY IN CHILDREN/SURVIVORS OF ACUTE LYMPHOBLASTIC LEUKEMIA

OBJECTIVE

to assess the thyroid disease in the late observation period in children who had received chemo- andradiotherapy for the acute lymphoblastic leukemia (ALL) taking into account gender, age period and disease sub-type.

MATERIALS AND METHODS

The incidence and nature of thyroid disease (hypothyroidism, thyroiditis, and thyroid can-cer) were studied in children-survivors of acute lymphoblastic leukemia (ALL) being in remission from 6 to 25 years.The distribution of patients by leukemia subtypes was as follows: «common» - 67.4 %, pre-B - 23.9 %, pro-B andT-cell - 4.3 %. Children had been receiving chemo- and radiotherapy according to the protocol. Regarding the ageof patients at the time of ALL diagnosis the prepubertal, pubertal and postpubertal periods were taken into account.The endocrine diseases in family history, body weight at birth, serum content of free thyroxine, pituitary thyroid-stimulating hormone, cortisol, iron, ferritin and thyroperoxidase antibodies were evaluated and assayed.

RESULTS

Thyroid disease in children was emerging in the first 2-3 years after the ALL treatment with an incidenceof 22.8 % (hypothyroidism - 14.1 %, autoimmune thyroiditis - 7.6 %, papillary cancer - 1.1 %). Seven children inthis group had received radiotherapy (12-18 Gy doses) on the central nervous system (CNS). No correlation wasfound between the radiation exposure event itself, radiation dose to the CNS and thyroid disease in the long-termfollow-up period. Thyroid cancer had developed in a child 11 years upon chemo- and radiotherapy. Hypothyroidismwas more often diagnosed in the patients of prepubertal age (rs = 0.49). There were endocrine diseases in thefamily history in about a half of children, being significantly higher than in the general sample (р < 0.05). The bodyweight at birth of a child who had later developed hypothyroidism was less than in children having got thyroiditis(rs = 0.57).

CONCLUSIONS

Disorders in endocrine regulation and of thyroid in particular can affect the prognosis of blood can-cer course in the long-term follow-up in children, especially in prepubertal age, which requires systematic supervi-sion by hematologist and endocrinologist.

ASSESSMENT OF QUALITATIVE CHANGES IN PERIPHERAL BLOOD CELLS IN CHILDREN - RESIDENTS OF RADIOLOGICALLY CONTAMINATED TERRITORIES IN THE LATE PERIOD AFTER THE ChNPP ACCIDENT

OBJECTIVE

to establish the relationship between quantitative and qualitative parameters of peripheral blood cells(lymphocytes, neutrophilic granulocytes, monocytes, platelets) depending on the type of somatic diseases andannual internal radiation doses from 137Cs in children - residents of radiologically contaminated territories in thelate period after the Chornobyl Nuclear Power Plant (ChNPP) accident.

MATERIALS AND METHODS

There were 175 children included in the study comprising residents of radiologically con-taminated territories (n = 79) aged from 4 to 18 years. Annual internal radiation doses in children from 137Cs rangedfrom 0.004 to 0.067 mSv. Certain blood parameters were assessed in a comparative mode in children having got theradiation doses up to 0.01 mSv and higher. The comparison group (n = 96) included children living in settlementsnot attributed to the radiologically contaminated ones. Incidence and type of somatic diseases and its impact onquantitative and qualitative changes in blood parameters (i.e. lymphocyte, neutrophilic granulocyte, monocyte, andplatelet count) were studied. The cell size, state of nucleus, membranes and cytoplasm, signs of proliferative anddegenerative processes were taken into account.

RESULTS

Incidence and type of somatic diseases in children did not depend on the annual internal radiation dose.Number of cases of monocytosis was significantly higher among the children exposed to ionizing radiation than inthe comparison group (16.6 % vs. 7.3 %). There were, however, no correlation between these changes and radiationdoses. Number of activated blood monocytes with cytoplasmic basophilia and residues of nucleoli in nuclei washigher in individuals with internal radiation doses > 0.01 mSv. A direct correlation between the qualitative param-eters of monocytes and internal radiation doses was established (rs = 0.60; р < 0.001), as well as a direct correlationof different strength between qualitative parameters of blood cells, indicating their unidirectional pattern depend-ing on the somatic morbid conditions. Regardless of annual internal radiation dose, there was an increase in thenumber of degenerative and aberrant cells vs. the comparison group (р < 0.05), which could be due to the role ofnon-radiation factors.

CONCLUSIONS

Results of the assessment of quantitative and qualitative parameters of peripheral blood cells reflect-ed the state of morbid conditions in children and are of a diagnostic value. The identified dose-dependent changesin monocyte lineage of hematopoiesis may be the markers of impact of long-term radionuclide incorporation withfood in children living in environmentally unfavorable conditions after the ChNPP accident.

ENDOCRINE REGULATION OF ERYTHROID LINEAGE OF HEMATOPOIESIS IN CHILDREN LIVING UNDER A LOW-DOSE RADIATION EXPOSURE AFTER THE CHORNOBYL NPP ACCIDENT

OBJECTIVE

Elucidation of relationship between the levels of thyroid-stimulating hormone (TSH), free serum thyroxine, serum and urine cortisol and parameters of erythroid lineage of hematopoiesis to estimate the thyroid functionin children of prepubertal, pubertal, and postpubertal age permanently residing under a low-dose radiation exposureto determine the premorbid state of thyroid function.

MATERIALS AND METHODS

Children aged 3 to 18 years old (n = 203) living in the most intensively radionuclide-contaminated regions of Kyiv, Zhytomyr and Chornihiv oblasts of Ukraine after the Chornobyl NPP accident wereenrolled. Complaints of ossalgia, arthralgia, fatigue, bone fractures in the history, bone dysembryogenetic stigmata,hypermobility syndrome degree, and types of somatic diseases were taken into account. Peripheral blood countparameters, biochemical indices of blood serum were studied, namely the levels of total protein, cholesterol, creatinine and alkaline phosphatase activity. Levels of the free thyroxine, pituitary TSH, serum and daily urine cortisol, anddoses of radiation exposure were determined.

RESULTS

The radiation dose values in children ranged from (0.35 ± 0.09) mSv to (0.54 ± 0.12) mSv. There was nodifference between the parameters of erythroid lineage of hematopoiesis depending on radiation dose. At the levels of serum TSH up to 1.0 μIU/ml no correlation was found with cortisol levels; at TSH levels of 1.0-3.0 μIU/ml thecorrelation coefficient was r = 0.31; at TSH levels higher than 3.0 μIU/ml the correlation coefficient was r = 0.61probably indicating a compensatory role of adrenal cortex in children at risk of thyroid disease development. In children with joint hypermobility grade II there was a higher incidence of dentofacial anomalies (χ2 = 6.9), deformitiesof lower extremities (χ2 = 6.9), and dental caries (χ2 = 4.3) (p < 0.05). There was a direct correlation between theserum TSH level (over 3 μIU/ml) and micrognathia (brachygnathia) (r = 0.62) indicating the impact of thyroid disease on dentofacial development. The TSH at a level of upper limit of the reference range values may contribute toa decreased RBC count in peripheral blood, increased average volume and hemoglobin content in erythrocyte beingassociated with the initial manifestations of thyroid dysfunction.

CONCLUSIONS

Abnormal endocrine regulation of hematopoiesis affects the connective tissue, stromal microenvironment of bone marrow, and accordingly the erythroid branch of hematopoiesis in children, which may be relevant inthe development and course of oncohematological diseases.

PROGNOSIS OF ACUTE LEUKEMIA DEPENDING ON THE IRON METABOLISM PARAMETERS IN CHILDREN AFTER CHORNOBYL NUCLEAR POWER PLANT ACCIDENT

OBJECTIVE

To determine the influence of iron metabolism on the prognosis of acute lymphoblastic (ALL) and (AML)myeloblastic leukemia at the different phases of chemotherapy in children after Chоrnobyl accident.

MATERIALS AND METHODS

333 children (295 - ALL, 38 - AML) were examined at the stages of chemotherapy. Thecomparison group included 93 children without leukemia. Acute leukemia variants, patients survival, relapses, thenature of disease (live child or died), iron methabolism (morphometric parameters of erythrocytes, SI, SF, STf, TS),manifestations of dyserythropoiesis, bone marrow sideroblast and patients radiation dose were taken into account.

RESULTS

In 295 patients with ALL the following variants of leukemia were established: pro-B-ALL in 23, «common»type of ALL in 224, pre-B-ALL in 29, T-ALL in 19. Thirty eight patients were diagnosed with AML (11 - M1, 19 - M2,8 - M4). Doses of radiation in patients with AL were (2.78 ± 0.10) mSv and they did not correlate with clinical andhematological parameters, disease variant. Relapse rates and shorter survival were in patients with T-ALL, pro-B-ALLand AML with SF levels > 500 ng/ml (p < 0.05). The amount of children with normochromic-normocytic anemias andmanifestations of dysplasia of erythroid lineage elements was greater in the AML than in ALL. SF content in patientswas elevated during chemotherapy and was lower than the initial one only in the remission period. Transferrin wasreliably overloaded with iron: TS (70.2 ± 2.3) % compared with the control group (32.7 ± 2.1) %. Correlationbetween TS and survival of patients was detected (rs = -0.45). Direct correlation between the number of iron granules in erythrocariocytes and SF level (rs = 0.43) was established, indicating the phenomena of ineffective erythropoiesis.

CONCLUSIONS

The negative influence of iron excess in the patients body on the hemopoiesis function, manifestations of ineffective erythropoiesis and the course of acute leukemia in children have been established. Changes inferrokinetic processes in children can be the basis of leukemоgenesis development.

FEATURES OF CLINICAL SYMPTOMS AND SIGNS, HEMATOLOGICAL AND BIOCHEMICAL PARAMETERS IN CHILDREN WITH JOINT HYPERMOBILITY IN A LATE PERIOD UPON THE CHORNOBYL NPP ACCIDENT

OBJECTIVE

establishing the types and frequency of disembriogenetic stigma in children with joint hypermobility given the clinical and laboratory features, genetic component and endocrine regulation of these disorders in a late period upon the accident.

MATERIALS AND METHODS

Children (n = 109) inhabiting the radiologically contaminated territories and having the connective tissue dysplasia (CTD) signs were involved in the study. Diseases in family history, ossalgia complaints, fractures in a personal history, bone disembriogenetic stigma, joint hypermobility, type of somatic diseases, blood serum biochemical parameters (namely calcium, alkaline phosphatase, total protein, cholesterol, creatinine, iron, ferritin content), serum cortisol, free thyroxine, pituitary thyroid-stimulating hormone (TSH) levels, free amino acid composition in urine and radiation dose were considered.

RESULTS

Radiation doses in children having the CTD ranged from (0.37 ± 0.11) mSv to (0.56 ± 0.10) mSv with no difference from that in those without CTD. Joint hypermobility (JHM) correlated with cancer in family history (rs = 0.53) and lower extremity varicose vein disease (rs = 0.40) (p < 0.05). Incidence of ossalgia, easy fatigability, and bone fractures was higher in children with CTD. Anomalies of the dentofacial system were first in line (38.5 %) in these children. Proportion of children with grade II JHM and platypodia was lower (rs = 0.42), but with lower extremity deformations was higher (rs = 0.68) (p < 0.05) vs. in the control group. Iron and ferritin deficiencies both with lymphocytosis were more common in children with CTD than in the comparison group (p < 0.05). The increased content of oxyproline, lysine, proline both with glycine deficiency were detected in children having the CTD, i.e. an imbalance of amino acids from the collagen content was observed featuring a predominance of catabolic processes over anabolic ones. There was a direct correlation between the TSH level and the JHM grade (rs = 0.49), although the values of hormone concentration in these children did not exceed the reference range (maximum values were 3.3 μIU/ml).

CONCLUSIONS

The revealed abnormalities in amino acid content, ferrokinetics, and thyroid function indices can affect the collagen formation, organic matrix structure of bone tissue and significantly deregulate the hemato- poiesis. The later can underlie the pathways of haematologic malignancy development.

PROGNOSIS OF THE COURSE OF CHORNOBYL-ORIGINATED ACUTE LYMPHOBLASTIC LEUKEMIA IN CHILDREN IN UKRAINE DEPENDING ON THE REASON OF STANDARD CHEMOTHERAPY INTERRUPTION

OBJECTIVE

Estimation of the bone marrow haemopoietic status depending on the reasons and duration of breaks in a standard chemotherapy (BFM-ALL protocol) to predict the course of acute lymphoblastic leukemia (ALL) in chil- dren exposed to low doses of ionizing radiation after the Chornobyl accident.

MATERIALS AND METHODS

The ALL patients (n = 34) were examined within 5 stages of a program chemotherapy. The clinical symptoms, hemogram and myelogram data were analyzed. The radiation dose on bone marrow, initial leuko- cyte count, variants and prognosis of ALL course were accounted. Days of the stopped chemotherapy, type and fre- quency of complications (septic processes, febrile neutropenia, toxic hepatitis, granulocytopenia degree), and the prognosis of disease course (child living status, i.e. alive or died) were estimated.

RESULTS

There were abnormal differentiation processes and high percentage of lymphoblasts (86.2 ± 3.3) % in bone marrow in the 1st acute period. Hematological remission was established in all patients on the 33rd day of chemothe- rapy. In a half of cases the haematopoietic recovery occurred by a granulocyte-monocyte type. One third of patients presenting an erythroid type of haemopoiesis died later. The inverse correlation was found between the number of myelocaryocytes and disease prognosis (rs = -0.49). Breaks in chemotherapy for various reasons were recorded. The number of patients with granulocytopenia was greater at the phase 1 and 2 of protocol I and protocol M application, coinciding with a higher incidence of complications. An inverse correlations between the prediction of ALL course and sum of days of breaks between the protocol M and phase 1 of protocol II (rs = -0.56), as well as the duration of the phase 2 of protocol II (rs = -0.62) were found. The radiation dose on bone marrow was (5.37 ± 1.23) mSv. No relationship was found between the radiation doses, ALL variants and disease course.

CONCLUSIONS

Prognosis of ALL course in children depends on the type of haemopoietic recovery and reasons of breaks in a standard chemotherapy. Interaction between the haemopoiesis functioning and microenvironment and that of their regulation are the key mechanisms of above-mentioned abnormalities, which is the basis for further research.

State of erythroid, granulocyte and platelet branches of hematopoiesis on stages of chemotherapy in children with acute lymphoblastic leukemia, who were exposed to ionizing radiation after the Chornobyl NPP accident

OBJECTIVE

Evaluation of proliferation and differentiation processes of progenitor cells in bone marrow by the com position of elements of erythroid, granulocyte and platelet branches of hematopoiesis on the treatment stages in children with acute lymphoblastic leukemia (ALL), who were exposed to radiation from the Chornobyl NPP accident.

MATERIALS AND METHODS

The 46 children with ALL were studied, who lived in Kyiv, Zhytomyr and Chernihiv regions. Studies were conducted before the start of chemotherapy (ChT), on the 33 day of ChT (phase I), and after the com pletion of ChT (phase II). Exposure doses of patients, hemogram and myelogram parameters both with indices of mat uration of progenitor cells were evaluated. Signs of dysplasia of hematopoietic branch elements were revewed.

RESULTS

The 46 patients were studied. They have had the B ALL, namely pro B ALL (n=5), «common type» (n=36), pre B ALL (n=3), and T ALL in 2 other cases. In a debut of ALL the bone marrow was represented by lymphoblasts. Along with ChT conduction the bone marrow hematopoiesis recovered by such types, as erythroid, granulocyte, gran ulocyte whith monocytes, and uniform, when the cells number of all branches was within a normal quantity. At the phase ІІ of ChT the number of patients with hematopoiesis recovery by erythroid type decreased and number of chil dren with activation of granulocyte branch of hematopoiesis increased. In children with pro B ALL the number of erythroid elements was higher than normative at both ChT phases. A direct correlation was established between the number of myelokaryocytes (Mkc) and megakaryocytes (Mgkc) in both phase І and phase ІІ of treatment (Rs = +0.72; Rs = +0.56, respectively). There was no correlation between the radiation dose in patients (3.73 ± 0.12 mSv) and studied parameters.

CONCLUSIONS

Types of bone marrow recovery were established in ALL patients after the ChT indicating to the differ ent kinetic pathways of hematopoietic progenitor cells. Evaluation of reasons of prevalence of some hematopoietic branches will allow to reveal their role in leukemogenesis and to correct the treatment programs.

Lymphocytosis in children after the Chornobyl NPP accident

OBJECTIVE

To establish the sources of lymphocytosis in children living in ecologically unfavorable conditions after the Chornobyl Nuclear Power Plant accident aiming the high risk group formation for oncohematological diseases among the children's population.

MATERIALS AND METHODS

The 226 children with lymphocytosis were surveyed. The of child's life history and kind of somatic morbidity were considered. Quantitative and qualitative parameters of blood cells, biochemical indices including immunoglobulins (A, M, G), circulating immune complexes, phagocytosis indices were assayed.

RESULTS

Children with lymphocytosis were more often born with a high bodyweight, they demonstrated manifestations of constitutional lymphatism, lymphadenopathy and more often had respiratory infections. Quantitative and qualitative changes of hemopoietic elements depended on a type of a disease. Activation of lipid peroxidation, dysimmunoglobulinemia and increased level of circulating immune complexes were revealed. Treatment and preventive actions promoted normalization of hemogram indices in 58% of children surveyed.

CONCLUSIONS

The abnormalities in immune indices, activated lipid peroxidation in membranes of hemopoietic elements, and manifestations of granulocytopoietic disorders were established it children with lymphocytosis. Therefore these children can be attributed tot the group of increased risk on oncohematological disease.