PLASMA-CELL HYPERPLASIA AND MONOCLONAL PARAPROTEINEMIA IN HUMAN-IMMUNODEFICIENCY-VIRUS INFECTED PATIENTS

Twenty-seven bone marrow aspirates and biopsy specimens from human imm unodeficiency virus-positive patients with plasmacytosis were analyzed to identify the pathologic correlates of polyclonal and monoclonal hy pergammaglobulinemia in these patients, to compare the results with an other random group of similar human immunodeficiency virus patients wi th plasmacytosis who did not have serum protein electrophoresis, and t o evaluate the significance of the presence of monoclonal proteins in a few patients. Serum protein electrophoresis and immunoelectrophoresi s and/or immunofixation electrophoresis revealed monoclonal spikes in five of 18 patients tested. The remaining patients with an abnormal se rum protein electrophoresis showed a polyclonal hypergammaglobulinemia . Immunohistochemical stains for kappa and lambda light chains were pe rformed in the bone marrow specimens to determine the presence and/or absence of light-chain preponderance or monoclonality. The percentage of plasma cells varied from 5% to 30% and atypical plasma cells from 1 % to 20%. Plasma cell aggregates were present in every case, but varia ble in number and generally small. In all these cases, including those with monoclonal spikes, plasma cells expressed lambda and kappa light chains with approximately equal intensity. There were no identifiable morphologic differences between the two groups of patients. The parap roteins observed in these patients are likely a reflection of B-cell o veractivation. It is important to be aware of this peculiar subset of human immunodeficiency virus-infected patients to avoid an erroneous d iagnosis of plasma cell dyscrasia.