Abstract
Common variable immunodeficiency (CVID) is a primary disorder characterized by impaired B cell differentiation and defective immunoglobulin production. This condition often presents with a wide range of clinical manifestations, including increased frequency and severity of infections, autoimmune diseases, and inflammatory disorders, which can lead to delays in diagnosis. Granulomatous involvement of the brain is an extremely rare but severe manifestation of CVID. We present a case of a woman in her 30s with a history of Evans syndrome and lymphocytic alveolitis who was admitted with persistent headache without neurological symptoms. Imaging revealed multiple infiltrative brain lesions. Despite the absence of recurrent infections, the patient's history of autoimmune manifestations and immunoglobulin deficiencies led to the diagnosis of CVID without the need for a brain biopsy. Treatment with intravenous immunoglobulin and immunosuppressive therapy resulted in significant clinical improvement and resolution of brain lesions. This case highlights the importance of considering CVID in patients with autoimmune manifestations and the effectiveness of prompt immunoglobulin replacement and immunosuppression in managing severe presentations of this condition.