Cortisol level as risk factor for malignant hematologic pathology in children exposed to ionizing radiation after Chornobyl accident.

Objective: Determination of serum cortisol level in the initial period of acute leukemia in children, who exposed to ion izing radiation and other factors of Chornobyl accident, depending on their age and prognosis of disease.

Materials And Methods: The study involved 283 children residents of Kyiv, Zhytomyr and Chernihiv regions. There were 90 acute leukemia patients(AL) (ALL - 56, AML - 34), and 193 people of comparison group with anemia, leukemoid reactions and lymphadenopathy. We analyzed the type of comorbid somatic pathology, diseases in the genealogy, hematological parameters, cortisol levels in blood serum and irradiation doses in all children. In patients with AL expected median survival was calculated.

Results: In 28.9 % of AL children the initial cortisol content was below 200 nmol/l, in 7.8 % - higher than 500 nmol/l (in the comparison group 10.4 % and 17.1 % respectively). Among AL patients with cortisol levels below 200 nmol/l were significantly less amount of persons with chronic bacterial infections and persistent viral infections (CMV, EBV) and in the genealogy of these children allergic reactions, endocrine pathology diagnosed more often compared with patients, whose hormone levels was higher than 200 nmol/l (p < 0.05). Distribution of children from control group by gradations of cortisol, age groups, defined somatic pathology and diseases in genealogy had no difference. It is shown, that lower initial blood serum cortisol level in ALL children correlates to a greater probability of relapse (Rs = -0,67). In patients with AML a direct correlation between cortisol level and median survival was detected (Rs = 0,79). Children radiation doses were ranging from 0.08 mSv to 14.9 mSv, and there were slightly higher among residents of Zhytomyr region (8.4 ± 1.2 mSv) compared to other regions. However, these doses did not affect blood serum cortisol levels in children and the course of AL.

Conclusions: These data suggest the need for correction and individualization of corticosteroid doses for optimization of AL patients treatment. Children, who have lower than normative serum cortisol levels are at increased risk of hema tologic pathology and they need for hematologic monitoring.