STORAGE HISTIOCYTES AND HEMOPHAGOCYTOSIS - A COMMON FINDING IN THE BONE-MARROW OF PATIENTS WITH ACTIVE SYSTEMIC LUPUS-ERYTHEMATOSUS

We report the frequency of the finding of storage and hemophagocytic h istiocytes in the bone marrow of patients with systemic lupus erythema tosus with one or more hemocytopenias. The study was performed on bone marrows of ten patients with systemic lupus erythematosus during an e pisode of hemocytopenia. Pour patients were not receiving any treatmen t and six had been taking oral prednisone (3.5 +/- 1.5 mg/day) for the previous 6 months. Hemocytopenias found were lymphocytopenia in five, thrombocytopenia in three, and neutropenia and anemia in two each. Th e bone marrow had variable cell content; megakaryocytes, the myeloid:e rythroid ratio, as well as lymphocyte, plasma cell, and reticular cell contents were usually increased. Seven bone marrow samples showed sto rage histiocytes (sea-blue histiocytes and other histiocytes that cont ained unidentified intracytoplasmic material). These same samples reve aled histiocytes phagocytosing erythoblasts, erythrocytes, polymorphon uclear neutrophils, lymphocytes or platelets. The presence of these hi stiocytes in all seven patients was related to a decrease in serum com plement and with lupus disease activity as measured with the SLEDAI in dex ((X) over bar +/- SD = 2.1 +/- 1.5). The SLEDAI score of the remai ning three patients, who had no histiocytes in their bone marrow, was 0, 0, and 1, respectively. The present study reveals that the bone mar row in patients with systemic lupus erythematosus and peripheral hemoc ytopenia contains storage and hemophagocytic histiocytes and the signi ficance of these cells is discussed.