Pathomorphology of humoral, cellular and combined primary immunodeficiencies.

Histologic, immunohistologic and electron microscopic findings in three children with primary immunodeficiencies are reported. Classical X-linked infantile agammaglobulinemia Bruton was present in case 1 (male, aged 16 years), selective cellular immunodeficiency with thrombopenia in case 2 (male, aged 2 1/2 years) and non-lymphopenic severe combined immunodeficiency in case 3 (male, aged 1 3/4 years). At autopsy, all three cases exhibited unusual types of pneumonia. In case 2 a generalized cytomegalovirus infection was present. Case 3 disclosed panmyelopathia and chronic liver lesions due to severe GvH-reaction subsequent to bone marrow transplantation. A detailed morphologic study of the immune system revealed distinct alterations in the thymus, spleen, and lymph nodes and the lymphatic tissues of the gastrointestinal tract characteristic of an immunodeficiency state, either humoral (case 1), cellular (case 2) or combined (case 3).