Infectious Diseases and Secondary Antibody Deficiency in Patients from a Mesoregion of São Paulo State, Brazil

TL;DR

This study examines antibody deficiency and infection patterns in Brazilian patients with various diseases, finding that some treatments increase infection risks.

Contribution

The study identifies SAD profiles and infection trends in a Brazilian mesoregion, linking immunosuppressants to hypo-γ-globulinemia and infection risks.

Findings

Nephrotic syndrome patients had lower infection rates compared to NHL patients (p = 0.0001).

Respiratory tract infections and pneumonia were the most common infection types.

Immunosuppressants led to hypo-γ-globulinemia and increased mild/moderate infections.

Abstract

Our aim was to determine the secondary antibody deficiency (SAD) profiles of patients in a mesoregion of São Paulo state, Brazil, focusing on infectious diseases. Demographic characteristics, and clinical and laboratory data were obtained from electronic files; infections were classified as organ-specific and graded as mild, moderate, life-threatening, and fatal. Non-Hodgkin’s lymphoma (NHL) accounted for 30% of patients, nephrotic syndrome (NS) 25%, chronic lymphocyte leukemia 20%, and multiple myeloma 15%. Patients with NS were younger than those in other groups, and hypo-γ-globulinemia was detected in 94.1%, IgG < 400 mg/dL in 60.0%, IgA < 40 mg/dL in 55.0%, and CD19 < 20 cells/mm3 in 30.0%. One hundred and one infections were found; 82.1% were classified as mild or moderate, 7.9% as life-threatening, and 3.0% as fatal. Respiratory tract infections were more prevalent (41.5%), and pneumonia accounted for 19.8%. Lower levels of infections were found in patients with NS compared with NHL (p = 0.0001). Most patients progressed to hypo-γ-globulinemia and SAD after treatment with immunosuppressants, and mild and moderate infections were predominant. These therapies are increasing in patients with different diseases; therefore, monitoring hypo-γ-globulinemia and infections may help to identify patients at high risk for severe complications, antibiotic prophylaxis or treatment, and immunoglobulin replacement.

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