Abstract
Common variable immunodeficiency is a group of heterogeneous diseases that are primary immunodeficiencies with a predominant lack of antibody synthesis. The most common manifestation is chronic infectious pathology of the respiratory tract, less often of the gastrointestinal tract, as well as septic arthritis. Non-infectious manifestations include autoimmune diseases, non-infectious diarrhea, cancer, benign lymphoid hyperplasia. In one patient, a combination of several syndromes is possible. Unlike most other primary immunodeficiencies that debut in early childhood, this pathology often manifests in the third or fourth decade of life, and sometimes later in apparently healthy people. Although the routine laboratory method for determining the concentration of the main classes of immunoglobulins makes it quite easy to identify patients with common variable immunodeficiency, often the diagnosis is made many years after the onset of the first clinical symptoms, when serious complications have already developed. The disease is characterized by a gradual onset, chronic progressive course and ineffectiveness of standard therapy. The main method of treatment is lifelong replacement therapy with intravenous immunoglobulins. The article considers a clinical case when an elderly patient with seronegative rheumatoid arthritis with a juvenile onset was diagnosed many years later. The results of immunological studies, including immunophenotyping of peripheral blood and bone marrow lymphocytes, are presented. Issues of differential diagnosis with secondary hypogammaglobulinemia and lymphoproliferative diseases are highlighted. It has been stated that until now, doctors of various specialties are not sufficiently familiar with the problem of primary immunodeficiencies, especially when it comes to adults, and non-infectious manifestations dominate in the clinical picture.