First part. A 45-year-old man with severe pneumonia, disseminated cytomegalovirus infection, and agammaglobulinemia

A 45-year-old male patient presented with a persistent cough lasting four months, accompanied by fever and significant weight loss. A chest computed tomography revealed cryptogenic pneumonia, and subsequent investigations identified a positive cytomegalovirus (CMV) viral load in bronchoalveolar lavage. A transbronchial biopsy confirmed intranuclear basophilic inclusions indicative of CMV infection. Additionally, blood tests returned positive results for CMV. Immunoglobulin levels revealed IgA < 0.13, IgG < 3, IgM < 0.25 (g/L). Bone marrow biopsy indicated an 80% hypercellularity without morphological alterations. Additional studies for agammaglobulinemia were asked for.