Abstract
ObjectiveTo investigate the clinical features of multicentric reticulohistiocytosis (MRH). MethodsThe clinical manifestations, laboratory examination results and histologic characteristics of eleven patients with MRH were collected and compared with those of 33 patients with rheumatoid arthritis. ResultsIn total, 72.7% of the MRH patients were women. The median age was 46 years (range: 33-84 years). Diagnosed by specific pathologic features, all MRH patients exhibited cutaneous involvement. The dorsa of the hands, arms, face and auricle were the most commonly affected areas. Nodules were also located on the legs, scalp, trunk, neck, and even the hypoglossis and buccal mucosa. Ten MRH patients (90.9%) had symmetric polyarthritis. Compared with rheumatoid arthritis (RA) patients, MRH patients were more likely to have distal interphalangeal joint (DIP) involvement (63.6% vs 24.2%, P=0.017) and less likely to have elbow (36.4% vs 72.7%, P=0.003), ankle (45.5% vs 93.9%, P<0.001) and metacarpophalangeal joint (MCP) (36.4% vs 78.8%, P=0.009) involvement. The positivity for rheumatoid factor (RF) (36.4% vs 84.6%, P=0.001) and anti-CCP antibody (9.1% vs 81.8%, P=0.000), as well as the median RF titer [43.8 (31.7-61.0) vs 175.4 (21.3-940.3), P = 0.021], in MRH patients was lower than that in RA patients. Elevation of the erythrocyte sedimentation rate (ESR) was also less common in MRH patients than in RA patients (36.4% vs 72.7%, P=0.030). After treatment with median- to large-dose corticosteroids and disease-modifying antirheumatic drugs, 8 patients achieved complete remission, and 2 patients achieved partial remission (skin lesions ameliorated, joint lesions not ameliorated). ConclusionAlways pathologically diagnosed, MRH is a systemic disease involving RA-like erosive polyarthritis and a specific distribution of skin nodules characterized by "coral beads". More DIP involvement and less elbow, ankle and MCP involvement are seen in MRH than in RA. In addition, less positive and lower-titer RF, uncommon presence of anti-CCP antibodies and ESR elevation may be helpful to distinguish MRH from RA.
Targetable driver mutations in multicentric reticulohistiocytosis
