A Short Case Series of Common Variable Immunodeficiency From a Tertiary Care Hospital in South India.

Common variable immunodeficiency (CVID) is the most prevalent clinically significant primary antibody deficiency, characterised by markedly reduced serum immunoglobulin levels and impaired vaccine responses. It typically presents with recurrent sinopulmonary infections and may be associated with autoimmune phenomena, granulomatous disease, and malignancy. Despite its clinical impact, CVID remains substantially underdiagnosed, with a considerable delay between symptom onset and diagnosis. We present three cases managed at a tertiary care centre in Kerala, India, illustrating the diverse clinical presentations of CVID across different age groups. The first was a 32-year-old woman with long-standing bilateral bronchiectasis, prior lung surgery, and recurrent infections attributed to severely reduced IgG and IgA levels. The second was a 14-year-old girl with recurrent respiratory and ear infections since childhood, bronchiectasis, clubbing, and lymphadenopathy, in whom marked hypogammaglobulinemia supported the diagnosis of CVID after exclusion of secondary causes. The third was a 50-year-old man presenting with consolidation, maxillary sinusitis, and significant weight loss, in whom pan-hypogammaglobulinaemia involving IgG, IgA, and IgM supported the diagnosis. These cases underscore the importance of maintaining a high index of suspicion for primary immunodeficiency in patients across all age groups presenting with recurrent sinopulmonary infections. Early immunological evaluation, including serum immunoglobulin quantification, is essential for timely diagnosis, and immunoglobulin replacement therapy remains the cornerstone of management.