Bone marrow findings in connective tissue disease

The authors studied 35 marrow biopsies from 32 patients with rheumatoid arthritis, systemic lupus erythematosus, mixed connective tissue disease, polymyositis, and psoriatic arthritis. Reasons for biopsy included cytopenia, fever of unknown origin, and malignancy. Cellularity was abnormal in 71%. Plasma cells were increased in 60% and associated with lymphoid aggregates. Immunoperoxidase stains showed polyclonal perivascular plasma cells and increased T-cells forming lymphoid aggregates. Two patients had granulomas without documented infection. Anemic patients had findings consistent with anemia of chronic disease, erythroid aplasia, hemolysis, and iron deficiency. Iron stores were variable. Platelet and granulocyte precursors were variably altered and did not predictably correlate with the presence, absence, or cause of thrombocytopenia and neutropenia. Myelodysplastic syndromes were present in two patients with rheumatoid arthritis. Osteomalacia and osteoporosis were seen, resulting from renal failure and steroids. Marrow findings are unpredictable and reflect the diverse causes of cytopenias in patients with connective tissue disorders.