The paradigm of possibilities leading to the formation of autoimmune and infectious phenotypes of common variable immune deficiency

The term variable in the definition of CVID is associated with the heterogeneity of the genetic nature and clinical manifestation of this variant of PI. Deciphering of the mechanisms or identifying biomarkers of clinical heterogeneity may be important in the timely diagnosis and prognosis of the course of CVID. The purpose of the study was to identify distinctive features in the parameters of the innate and adaptive immune response of the patients with infectious and autoimmune manifestations of CVID in remission and clinical manifestation. Fifteen patients, 11 women and 4 men with an average age 39.7±11.7 years were examined, and they were divided into two subgroups depending on clinical verification: infectious phenotype (10 people) and autoimmune phenotype (5 people). In the absence of clinical signs of activation of autoimmune pathology or exacerbation of chronic infectious processes, peripheral blood monocytes became the application point of distinctive values. An increase in the number of TLR9-expressing monocytes has been shown in patients with autoimmune clinical verification of CVID. The differences in the parameters of the immune status of patients conducted during the period of clinical manifestation consisted of a decrease in the relative content and absolute number of T regulatory lymphocytes, and an increase in the number of monocytes containing TLR9, TLR2 and HLA-DR in patients with an autoimmune phenotype relative to the subgroup with infectious manifestation. The data obtained reflect the involvement of the immunoregulatory potential of the immune system in the clinical manifestation of primary immunodeficiency, even under the conditions of pathogenetic substitution therapy. The evidence of the stated position is a decrease in immunosuppression in autoimmune manifestation due to a decrease in the number of peripheral T-regulatory cells and a smaller proportion of monocyte cells belonging to the M2 suppressive category. Attention is also drawn to the increased potential of primary response to patterns of various nature in autoimmune manifestation due to an increase in the number of monocytes expressing Toll-like receptors of various specificity. The presented results can be proposed as a diagnostic and prognostic indicator of the difference in clinical phenotypes of CVID.