Clinical and immunological characteristics of 88 cases of overlap myositis / 北京大学学报(医学版)

OBJECTIVE@#To investigate the clinical and immunological characteristics of overlap myositis (OM) patients.@*METHODS@#The data of 368 patients with idiopathic inflammatory myopathies (IIMs) admitted to Peking University People's Hospital from January 2004 to August 2020 were analyzed retrospectively, including demographic characteristics, clinical characteristics (including fever, Gottron' s sign/papules, Heliotrope rash, V-sign, Shawl sign, Mechanic' s hands, skin ulceration, periungual erythema, subcutaneous calcinosis, dysphagia, myalgia, myasthenia, arthritis, Raynaud' s phenomenon, interstitial lung disease, pulmonary hypertension and myocardial involvement), laboratory characteristics, immunological characteristics [including antinuclear antibodies, rheumatoid factors, myositis-associated autoantibodies (MAAs) and myositis-specific autoantibodies (MSAs)] and survival. The clinical and immunological characteristics and prognostic differences of OM and non-OM were compared. The Kaplan-Meier and Log Rank methods were used to analyze the survival.@*RESULTS@#A total of 368 patients were included. 23.9% (88/368) of IIMs patients were OM patients. Among the 88 OM patients, 85.2% (75/88) of them were female, and the median interval between disease onset and diagnosis was 13.5 months. The incidence of overlapped connective tissue diseases in the OM patients was dermatomyositis (DM) in 60.2%, polymyositis (PM) in 3.4%, immune-mediated necrotizing myopathy (IMNM) in 2.3% and anti-synthetase syndrome (ASS) in 34.1%. Compared with the non-OM patients, the proportion of the females in the OM patients was higher (85.2% vs. 72.1%, P=0.016), the OM patients had longer disease duration [13.5(4.5, 48.0) months vs. 4.0(2.0, 12.0) months, P < 0.001]. As for clinical characteristics, compared with the non-OM patients, the incidence of V-sign (25.0% vs. 44.6%, P=0.001) and periungual erythema (8.0% vs. 19.6%, P=0.013) were lower; the incidence of Raynaud's phenomenon (14.8% vs. 1.8%, P < 0.001), interstitial pneumonia (88.6% vs. 72.1%, P=0.001), pulmonary hypertension (22.7% vs. 7.5%, P < 0.001) and myocardial involvement (18.2% vs. 9.3%, P=0.033) were higher. As for immunological characteristics, compared with the non-OM patients, the incidence of elevated aspartate aminotransferase (AST) (31.8% vs. 45.0%, P=0.035) was lower and elevated C-reactive protein (CRP) (58.0% vs. 44.6%, P=0.037) was higher; the positive rates of antinuclear antibodies (ANA) (85.1% vs. 63.4%, P=0.001) and rheumatoid factors (RF) (40.2% vs. 17.8%, P < 0.001) and anti-Ro-52 (71.6% vs. 56.1%, P=0.038) in serum were higher. There was no significant difference in the survival between the OM patients and non-OM patients.@*CONCLUSION@#Pulmonary hypertension and myocardial involvement were frequently observed in OM.

Juvenile idiopathic inflammatory myopathies: A clinicopathological study with emphasis on muscle histology

Background: Juvenile idiopathic inflammatory myopathies (JIIM) are rare and heterogeneous. Subtype identification is important for treatment. Materials and Methods: Patients below 18 years diagnosed as idiopathic inflammatory myopathy (IIM) according to the Bohan and Peter criteria between January 2010 and May 2015 were evaluated with muscle biopsy in the four domains: muscle fiber, inflammation, connective tissue, and vascular, with basic panel of histochemical stains as per recommendations of the European Neuromuscular center (ENMC) workshop 2015. Immunohistochemistry with CD 31 was done to assess capillary density. Results: JIIM constituted 15.25% of IIM with juvenile dermatomyositis (JDM) being the most common subgroup (24/27) followed by juvenile overlap myositis (JOM) (3/27) in association with systemic lupus erythematosus (2) and systemic sclerosis (1). Muscle biopsy in JDM was characterized by perifascicular atrophy, necrosis, degeneration, and regeneration in all and the other features included perivascular inflammation (21), lymphoid aggregates (2), mitochondrial abnormalities (9), sarcoplasmic vacuoles (6), capillary dropout (5), capillary dilatation (6), and perimysial fibrosis (14). JOM was characterized by auto-antibodies and perivascular inflammation. Conclusion: JIIMs were rare and JDM was the most common subtype. Muscle biopsy evaluation as per ENMC criteria characterized the subgroups.