Morphologic findings in children with acquired immune deficiency syndrome: pathogenesis and clinical implications.

The lesions observed in biopsy and autopsy material from children with the acquired immunodeficiency syndrome (AIDS) can be divided into three pathogenetic categories: primary lesions related to infection by human immunodeficiency virus (HIV) (e.g., lymphoreticular system and brain); lesions due to the sequelae of HIV infection (e.g., opportunistic infections, pulmonary lymphoid lesions, etc.); and lesions of undetermined pathogenesis (e.g., renal lesions, cardiomyopathy, etc.). The role of morphologic studies in AIDS in understanding the pathogenesis of the various lesions and their clinical implications are discussed by describing the following examples among others. Study of the thymus enabled us to distinguish AIDS from some congenital immune deficiency syndromes. Thymic injury contributes to immunodeficiency in AIDS. Its apparent irreversibility will have to be considered in the long-term management of children with AIDS when specific effective therapy for HIV becomes available. Demonstration of HIV--like particles in the characteristic giant cells in the brain has been instrumental in the recognition of HIV encephalopathy. Biopsy is helpful in the rapid diagnosis of opportunistic infections (OIs). Autopsy study of OIs has shown involvement of clinically unsuspected organs, such as the adrenals. Characterization of the pulmonary lymphoid lesions led to their inclusion as a diagnostic criterion for AIDS in children. Progression of pulmonary lymphoid lesions to a lymphoproliferative disorder was demonstrated at autopsy. Recognition of lesions such as cardiomyopathy and arteriopathy at autopsy should alert clinicians to suspect these disorders during life.