Background: Exposure of anthropogenic origin chemicals on the human organism leads to the stress of adaptive mechanisms, disfunctions of regulatory systems, including the immune system, formation of immunopathological states, which are caused by immunotoxicity of xenobiotics. Chemicals, possessing expressed immunotoxicity, are formaldehyde, phenol and the majority of aromatic hydrocarbons (benzene, toluene, xylene, and styrene).
Aim & Objectives: The purpose of investigation was to define the method of early diagnosis of the immune system disfunctions in children, living in conditions of the impact of organic compounds possessing the immunotoxicity.
Methods/Study Design: Within the research 492 children, living near the oil refining complex, were observed. Comparison group consisted of 165 children living on the territory of relative well-being. Age of children is 3-15 years (median age in groups was 7,32 ± 1,55 and 8,12 ± 0,92 years, respectively). In the represented research the complex of clinical and laboratory examination methods was used: physical (general blood analysis - white blood cells, neutrophils, lymphocytes), immunological methods. Organic compounds (phenol, toluene and formaldehyde) in the blood were determined according to methodological guidelines "Determination of chemical compounds in biological media" (MG 4.1.763-4.1.779-99) and "Determination of hazardous substances in biological media"(MG 4.1 .2102-4.1.2116-06) by paraphase analysis method with various embodiments of sample preparation. All the examined children were subject to the standard examination of spleen on the ultrasound diagnostic system Toshiba APLIO XG SSA-790A (Japan) and evaluation of splenic tissue echostructure using the multifrequency linear array sensor with the frequency of 10 MHz. For early diagnosis of immune system disfunction it is necessary to develop the screening, reliable noninvasive instrumental methods of investigation, allowing in timely manner to verify the adverse impact of technogenic factors on the child's body. For this purpose all the examined children of the core group have been divided into two groups: 1st Group and 2nd Group. 1st Group comprised 256 children the spleen echostructure of which was characterized by the presence of multiple hypoechogenic homogeneous roundish inclusions throughout the ultrasonic section of the organ ranging in the size from 0.3 mm to 1 mm, located at a distance about 1.5-2 mm from each other. 2nd group included 236 children that according to ultrasound investigation had no disturbances in echostructure of spleen and it was characterized as homogeneous and finegritted.
Results/Findings: The children of the 1st group have the mean group values of toluene, phenol, formaldehyde that are higher (p ≤ 0.05) than in 2nd group. The results of mathematical modeling, characterizing the relationship between levels of immunological blood parameters and concentration of toxic chemical substances in the blood of children of 1st group has testified about statistically significant effect of investigated organic compounds on the parameters of immunological homeostasis (p ≤ 0,05). It is possible that in conditions of influence of toxicant load occurs an adaptive change of immune status that involves activation of proliferative processes in lymphoid follicles of the spleen. Eventually it is visualized at carrying out of ultrasound investigation and can be regarded as an increase in the share of white pulp of the spleen. It is established that at increase in concentration of toluene in blood the probability of detection in a blood the high level of CD19 +-lymphocytes is statistically significantly increased. With increasing the concentration of formaldehyde in a blood the T-cellular link of immunity is activated. It was also established that with increasing the level of phenol in the blood it is also registered the decrease in the content of IgG. Conclusion: Children living in urbanized territories contaminated by chemicals with anthropogenic origin with the developed oil refining industry and having changes in echostructure of spleen in the form of multiple hypoechogenic homogeneous roundish inclusions throughout the ultrasonic section of organ (increasing of white pulp with lymphoid proliferation) having the blood with higher levels of organic compounds (toluene, phenol, formaldehyde) than children with intact spleen. Ultrasound investigation of spleen with the analysis of its echostructure can be recommended as a screening method for assessing of an adverse effect of technogenic environmental factors on the condition of immune system of children living in urbanized territories.