The bone marrow in AIDS. A histologic, hematologic, and microbiologic study

During one year, 55 bone marrow biopsies from 49 patients with CDCdefined acquired immune deficiency syndrome (AIDS) were studied. Eighty-three percent were normocellular or hypercellular; 17% were hypocellular. Marrow plasma cells were increased in 83% of patients, most showing polyclonal hypergammaglobulinemia. Forty percent of patients showed peripheral neutropenia, 29% thrombocytopenia, and 79% lymphopenia with markedly reduced T4⁺ lymphocytes. Eighty-five percent of patients were anemic, with iron studies showing a pattern consistent with the anemia of chronic disease. Mycobacterium avium-intracellulare (MAI) grew from ten (20%) biopsies, four with granuloma and six without granuloma (five of these six also showed marrow hypocellularity). Small poorly formed granuloma (70-150 μm) were seen in eight (16%) patients (four AFB-culture positive, 4 negative). Three of four granuloma-positive, culture-negative cases eventually grew MAI from autopsy material. Five (10%) patients had lymphoplasmacytic aggregates; later, one developed lymphoma, another, markedly atypical lymphoid hyperplasia. Two additional patients showed marrow B-cell lymphomas. Of these findings, only marrow MAI meets the CDC definition of AIDS. However, in this series, small ill-defined granulomas, lymphoplasmacytic aggregates, and B-cell lymphomas also were found. The authors conclude that these latter findings, when seen in high-risk patients, particularly those with lymphopenia, anemia, and/or hypergammaglobulinemia, also strongly suggest the diagnosis of AIDS.