[Clinical profile of patients with secondary immunodeficiency on immunoglobulin replacement therapy].

Background: Secondary immunodeficiency (SID) is a disorder in which the immune system is compromised by external or acquired factors, reducing the quantity or function of immunoglobulins. This condition increases the need for specialist consultation, follow-up, and replacement therapy, which in turn raises healthcare costs. To date, few studies have clinically characterized patients with SID; therefore, understanding their profile will enable improved management and treatment. Objective: To describe the clinical profile of patients with SID receiving human immunoglobulin replacement therapy (IgG-RT). Material and methods: A retrospective observational study was conducted through the review of 40 medical records of patients with SID undergoing IgG-RT. Risk factors and the benefits of replacement therapy were analyzed. Results: The mean age was 48 years, with a predominance of women (62.5%). The most frequent conditions were rheumatologic diseases (38%), followed by hematologic disorders (31%) and protein-losing diseases (27%). All patients had received corticosteroids in combination with another immunosuppressant, and 77.5% had also been treated with rituximab. Infections were recorded in 50% of cases; however, only 35% received prophylaxis. Relapse was documented in 22.5% of patients, and mortality was 2.5%. Conclusions: The use of corticosteroids and immunosuppressants, specifically rituximab, was the main cause of SID, predominantly associated with rheumatologic and hematologic diseases.