The aim was to study the prevalence, rate of appearance and severity of clinical features in patients with different anti-synthetase syndrome (ASyS) autoantibodies.
All Johns Hopkins Myositis ...Longitudinal Cohort subjects positive for any ASyS autoantibodies were included. Clinical information, including symptoms, signs, strength, creatine kinase concentrations and pulmonary function tests, were prospectively collected. The standardized mortality and cancer rates and the rate of appearance and intensity of the different organ manifestations were assessed using univariate and multivariate analysis and compared between ASyS autoantibodies.
One hundred and twenty-four (73.4%) patients were positive for anti-Jo1, 23 (13.6%) for anti-PL12, 16 for anti-PL7 (9.5%) and 3 (1.8%) for anti-EJ or anti-OJ, respectively. The mean length of follow-up was 4.1 years. Anti-PL12 was more frequent in black subjects. Anti-PL12 and anti-PL7 were associated with more prevalent and severe lung involvement, often without muscle involvement. Anti-Jo1 displayed more severe muscle involvement compared with anti-PL12 patients. Concurrent anti-Ro52 was more prevalent in anti-Jo1 patients and was associated with earlier development of mechanic's hands, DM-specific skin findings and arthritis. Independent of ASyS antibody status, black patients demonstrated more severe lung involvement than white patients. There was no significant increase in mortality or cancer risk in ASyS patients compared with the general US population.
Different ASyS autoantibodies are associated with phenotypically distinct subgroups within the ASyS spectrum. Anti-PL7 and anti-PL12 are characterized by more severe lung involvement, whereas anti-Jo1 is associated with more severe muscle involvement. Black race is a major prognostic factor associated with lung disease severity.
Statins up-regulate expression of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR), the rate-limiting enzyme in cholesterol synthesis and the major target of autoantibodies in ...statin-associated immune-mediated necrotizing myopathy. As muscle cells regenerate, they express high levels of HMGCR, which may sustain the immune response even after statin therapy is stopped. Awareness of this entity will help physicians who prescribe statins to take action to limit the associated morbidity.
To study disease severity and response to therapy in a large cohort of patients with anti-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR)-associated myositis.
Muscle strength, creatine kinase ...levels and treatments were assessed in anti-HMGCR-positive patients at each clinical visit. Univariate and multivariate analyses were used to analyse the influence of clinical characteristics on strength and the change in strength over time. Whole exome sequencing was performed in a subset of patients.
. Among 50 patients followed for ⩾2 years, only 22 (44%) reached full strength with immunosuppressive therapy; even among those with full strength, 55% continued to have CK levels in excess of 500 IU/l and only three could be tapered off immunosuppressive therapy. Both univariate and multivariate analysis showed that patients who were older at disease onset were stronger at all time points (P < 0.001) and improved faster (P < 0.008) than younger patients; a history of statin exposure was not independently associated with the improvement rate. Younger patients were more likely to have refractory disease (P = 0.02) than older patients. Among eight refractory patients with DNA available for testing, whole exome sequencing did not reveal pathogenic mutations in known dystrophy genes. The risk of cancer was not increased in anti-HMGCR myositis patients compared with the general population.
Anti-HMGCR myositis is usually a chronic disease requiring long-term immunosuppression. Although younger patients had more severe disease and a worse prognosis than older patients, they did not have evidence of a known co-existing muscular dystrophy to explain their persistent, and sometimes progressive, muscle weakness.
Objective
Patients with immune‐mediated necrotizing myopathy (IMNM) often have autoantibodies recognizing the signal recognition particle (SRP) or HMG‐CoA reductase (HMGCR). Here, we studied a cohort ...of anti‐SRP patients to identify factors associated with disease severity and clinical improvement; we also compared the severity of weakness in those with anti‐SRP versus anti‐HMGCR autoantibodies.
Methods
All anti‐SRP patients in the Johns Hopkins Myositis Cohort from 2002 to 2015 were included. Longitudinal information regarding proximal muscle strength, creatine kinase (CK) levels, and immunosuppressive therapy was recorded at each visit. Univariate and multivariate multilevel regression models were used to assess prognostic factors influencing recovery. Strength in the anti‐SRP patients was compared to strength in 49 previously described anti‐HMGCR subjects.
Results
Data from 37 anti‐SRP patients and 380 total clinic visits were analyzed. Younger age at onset was associated with more severe weakness at the first visit (P = 0.02) and all subsequent visits (P = 0.002). Only 50% of patients reached near‐full or full strength after 4 years of treatment, and most of these continued to have elevated CK levels. Rituximab appeared to be effective in 13 of 17 anti‐SRP patients. Anti‐SRP patients were significantly weaker than those with anti‐HMGCR autoantibodies (−1.3 strength points; P = 0.001).
Conclusion
Younger age at onset is associated with more severe weakness in anti‐SRP myositis. Furthermore, even among anti‐SRP patients whose strength improved with immunosuppression, most had ongoing disease activity as demonstrated by elevated CK levels. Finally, anti‐SRP patients were significantly weaker than anti‐HMGCR patients, providing evidence that these autoantibodies are associated with distinct forms of IMNM.
The efficacy of azathioprine (AZA) and mycophenolate mofetil (MMF) for interstitial lung disease (ILD) has been described, but mainly in connective tissue disease-associated ILD. The objective of ...this study was to evaluate the effect of AZA and MMF on lung function and prednisone dose in myositis-related ILD (M-ILD).
In this retrospective study, patients with M-ILD seen at Johns Hopkins and treated with AZA or MMF and no other steroid-sparing agents were included. Linear mixed-effects models adjusted for sex, age, antisynthetase antibody, and smoking status were used to compare the change in FVC % predicted, diffusing capacity of the lungs for carbon monoxide (Dlco) % predicted, and prednisone dose.
Sixty-six patients with M-ILD were treated with AZA and 44 with MMF. At treatment initiation, mean FVC % predicted and Dlco % predicted were significantly lower in the AZA group than in the MMF group. In both groups, FVC % predicted improved and the prednisone dose was reduced over 2 to 5 years; however, for Dlco % predicted, only the AZA group improved. The adjusted model showed no significant difference in posttreatment FVC % predicted or Dlco % predicted between groups (mean difference of 1.9 and –8.2, respectively), but a 6.6-mg lower dose of prednisone at 36 months in the AZA group. Adverse events were more frequent with AZA than MMF (33.3% vs 13.6%; P = .04).
In M-ILD, AZA treatment was associated with improved FVC % predicted and Dlco % predicted, and lower prednisone dose. Patients treated with MMF had improved FVC % predicted and lower prednisone dose. After 36 months, patients treated with AZA received a lower prednisone dose than those treated with MMF.
PDF
