What is cvid

Overview

Common Variable Immunodeficiency (CVID) is a primary immunodeficiency disorder affecting the adaptive immune system's ability to produce adequate antibodies. Unlike X-linked agammaglobulinemia, CVID affects both males and females and has a more variable presentation, making diagnosis challenging.

Causes and Pathophysiology

CVID results from genetic mutations affecting B cell maturation and differentiation. While specific genes have been identified in some cases, the genetic basis remains unknown in most patients. The condition leads to significantly reduced levels of immunoglobulins (antibodies), particularly IgG, IgA, and IgM.

Clinical Symptoms

Patients experience recurrent infections including sinusitis, otitis media, bronchitis, and pneumonia. Some individuals also develop autoimmune conditions, granulomatous diseases, or malignancies. Symptoms vary widely in severity and onset.

Diagnosis

Diagnosis involves measuring serum immunoglobulin levels (typically IgG below 300 mg/dL) and assessing vaccine response. B cell numbers are usually normal or only mildly reduced, distinguishing CVID from other immunodeficiencies. Testing typically occurs when recurrent infections become concerning.

Treatment and Management

The primary treatment is immunoglobulin replacement therapy, either intravenous (IVIG) or subcutaneous (SCIg). Prophylactic antibiotics may be prescribed, and patients should avoid live vaccines. Regular monitoring for complications is essential.