Background Cytopenia in the course of systemic lupus erythematosus (SLE) may be due to multiple factors. One of these factors can be SLE-associated autoimmune myelofibrosis (AIMF). However, the frequency of SLE-associated AIMF is not well known and the role of clinical and laboratory parameters in the development of AIMF is not clear.
Objectives Our aim was to identify the frequency of SLE-associated AIMF and compared SLE-associated AIMF group with non-AIMF group in terms of clinical findings and morphological properties of the bone marrow (BM) in cytopenic SLE patients.
Methods We retrospectively analyzed 224 SLE patients' files who met 1997 revised Classification criteria for SLE. BM aspirates and trephine biopsies were re-examinded. Patients were divided into two groups according to whether they had myelofibrosis or not (AIMF and non-AIMF groups). Concurrent SLE organ involvements, and drugs given pre- and post-AIMF were recorded. BM cellularity, the presence of fibrosis (reticulin or collagen) and grade of fibrosis, the presence of dysplasia, and lymphoid infiltration were recorded.
Results 45 (20%) of 224 SLE patients were found to experienced BM biopsy due to cytopenia. Four patients were excluded from analyses (2 drug-induced cytopenia, 1 lymphoma, 1 insufficient BM biopsy samples). While AIMF was detected in 29 (70.7%) of the 41 patients, 12 patients did not have AIMF. All patients with AIMF had reticulin fibrosis, 2 patients (6.9%) had also collagen fibrosis. Between the AIMF and non-AIMF groups, no differences were identified in terms of erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), SLEDAI, BM cellularity, or BM dysplastic changes (p=0.989, p=0.387, p=0.788, p=0.672, and p=0.494, respectively). In the AIMF group, 27 patients responded to immunosuppressive therapy and corticosteroids, but 2 patients were unresponsive. The response time was longer for the AIMF group compared to the non-AIMF group (3.3±3.1 months vs 1.7±1.2 months, p=0.091). Correlation analysis revealed that higher the grade of BM fibrosis, longer the response time (r=0.471, p=0.002).
Conclusions AIMF may be underestimated in SLE patients. AIMF as an additional factor for cytopenia in SLE patients may lead to delayed response to appropriate therapy, which was dependent on the presence of high grade fibrosis.
Acknowledgements None declared
Disclosure of Interest None declared