Indications for bone marrow examinations in rheumatology

Hematologic involvement or hematologic malignancies are frequently encountered during the course of rheumatic diseases. Bone marrow (BM) aspiration and/or biopsy examinations may have a diagnostic role in explaining hematologic findings detected in rheumatology clinical practice. Our aim was to describe the indications for BM examinations and to share our BM aspiration/biopsy results. We analyzed 140 BM aspiration/biopsy results of patients conducted at the Department of Rheumatology from 2010 to 2018. Demographics, complete blood count (CBC), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) values, serum biochemistry test results including lactate dehydrogenase (LDH), organomegaly, indications for BM examinations and BM examination results for each patient, and mortality rates were recorded. Out of the 140 patients, 63.6% were female, and the median (Q1–Q3) age was 53 (39.5–65) years. One hundred fifteen (82.1%) patients were diagnosed as having primary rheumatic disease, and 25 (17.8%) were admitted due to musculoskeletal symptoms. Rheumatoid arthritis (RA) (n = 34, [29.5%]), and systemic lupus erythematosus (SLE) (n = 21, [18.2%]) were the most common rheumatic diseases. Cytopenia was the most common indication for BM aspiration/biopsy (n = 83, [59.3%]). Thirty-nine (47%) of 83 patients had drug-induced cytopenia. A pathology was detected in 40 (28.5%) of the 140 BM examinations. Patients with pathologic BM results had either a hematologic malignancy (n = 38, [95%]) or metastasis to a solid organ (n = 2, [5%]). The group of patients with pathologic BM biopsy results had significantly higher rates of lymphadenopathy, splenomegaly, and monoclonal gammopathy compared with the group with non-pathologic results (p = 0.001, p = 0.011, and p = 0.023, respectively). Likewise, LDH concentrations of those with pathologic results were higher than in patients with non-pathologic results [737 (range 577–1420) IU/L vs. 541 (range 306–840) IU/L, p = 0.019]. In this study, cytopenia or CBC abnormalities accompanied by elevated LDH values or anemia along with increased ESR were the most common indications for BM aspiration/biopsy. Further prospective studies are needed to determine the indications of BM aspiration/biopsy and establish the parameters that predict abnormal BM results in rheumatology practice.