Clinical and immunological features in children with secondary hypogammaglobulinemiae

Antibody deficiency may be a manifestation of primary immunodeficiency or can be generated by extrinsic factors. The frequency of secondary hypogammaglobulinemias has increased significantly in recent years in children with oncohematological pathology. Purpose — to study of clinical, biochemical and immunological indicators in children with secondary hypogammaglobulinemiae in order to determine management and treatment tactics. Materials and methods. 52 children with secondary hypogammaglobulinemiae were examined. Children were divided into 4 groups according to the primary diagnosis (acute myeloblastic, lymphoblastic leukemia and mixed phenotype leukemia, glomerulonephritis, nephrotic syndrome). Anamnesis and data of immunological (levels of serum immunoglobulins IgA, IgM, IgG, subpopulations of lymphocytes) evaluation prior to immunoglobulin replacement therapy. Results. Infectious diseases were observed in 22 children (42.3%). Allergic diseases occurred in 11 children (21%). Toxic complications of chemotherapy by internal organs and systems were found in 38 children (73%). Chronic kidney disease was diagnosed in 5 children (10%). The level of IgG was the lowest in children with nephrotic syndrome (2.6±1.54 g/l). The level of T lymphocytes — CD3+ (0.89±0.93x109/l) and T cytotoxic lymphocytes — CD3+CD8+ (0.33±0.38x109/l) were the lowest in the group of children with acute lymphoblastic leukemia. The level of T helper cells (CD3+CD4+) was low in the group of children with acute lymphoblastic (0.39±0.4x109/l) and myeloblastic leukemia (0.69±0.39x109/l). Level of B lymphocytes was low in the group of children with acute lymphoblastic (0.23±0.23x109/l) and myeloblastic leukemia (0), as well as in the group of children with nephrotic syndrome (0.18±0.13x109/l). Conclusions. Infectious diseases are common in children with secondary hypogammaglobulinemiae. In the group of children with acute leukemia bacterial and fungal diseases occurred more frequently and were more severe compared to the group of children with nephrotic syndrome. Therefore children with secondary hypogammaglobulinemia require control of serum immunoglobulin levels before starting immunosuppressive therapy, bone marrow transplantation and after its completion for the timely initiation of immunoglobulin replacement therapy in order to prevent infectious diseases and their complications. There is a need to determine serum antibody levels in children with nephrotic syndrome. The research was carried out in accordance with the principles of the Helsinki Declaration. The study protocol was approved by the Local Ethics Committee of a participating institution. The informed consent of the patient was obtained for conducting the studies. No conflict of interest was declared by the authors. Key words: secondary hypohammaglobulinemia, children, serum immunoglobulins, subpopulations of lymphocytes, nephrotic syndrome, proteinuria, acute leukemia.