Clinico-pathological phenotypes of systemic sclerosis-associated myopathy: analysis of a large multicentre cohort

OBJECTIVE

The objective of this study was to analyse the clinico-serological and histological phenotypes of patients with SSc with associated myopathy.

METHODS

From November 2002 to September 2020, 52 patients with SSc underwent a muscle biopsy for suspected myopathy. We established two subgroups according to the histological findings based on the presence of isolated fibrosis or fibrosis together with significant inflammation. These patterns were designated as fibrosing and inflammatory, respectively. Clinical data, antibody profile, electrophysiologic studies, muscle biopsy findings and data regarding treatment, mortality and survival were compared between the two groups.

RESULTS

Fourteen biopsies had a fibrosing pattern, whereas 26 showed an inflammatory pattern that could be classified (according to the predominant pattern) into DM (n = 7), necrotizing myopathy (n = 4) and non-specific myositis (n = 15). Additionally, 12 muscle biopsies were reported as neurogenic atrophy (n = 2), or normal muscle or minimal changes (n = 10). Compared with the inflammatory group, SSc patients with the fibrosing pattern presented a higher prevalence of ischaemic heart disease (38.5% vs 3.8%, P = 0.011), conduction abnormalities or arrhythmias (61.5% vs 26.9%, P = 0.036), anti-topo I antibodies (42.9% vs 11.5%, P = 0.044), greater median ESR (53.5 mm/h vs 32.5 mm/h, P = 0.013), with poor response to treatment and a higher mortality (42.9% vs 3.8%, P = 0.004) and lower cumulative survival (P = 0.035).

CONCLUSIONS

Patients with SSc-associated myopathy require a comprehensive approach that encompasses clinical, serological and histopathological aspects, given their outcome predictive capacity. At least two different phenotypes can be drawn, considering clinico-pathological features. Significant differences are delineated between both a fibrotic and an inflammatory phenotype.

POS1238 GLUCOCORTICOIDS, RITUXIMAB AND THE PRESENCE OF INTERSTITIAL LUNG DISEASE ARE ASSOCIATED WITH POOR OUTCOMES OF THE SARS-COV-2 INFECTION IN PATIENTS WITH RHEUMATOID ARTHRITIS: DATA FROM THE NATIONAL REGISTRY SAR-COVID

Background

High disease activity, treatment with glucocorticoids (GC) and rituximab (RTX), have been related to worse outcomes of COVID-19.

Objectives

To assess the clinical characteristics and severity of the SARS-CoV-2 infection in patients with rheumatoid arthritis (RA) included in the SAR-COVID registry and to identify factors associated with poor outcomes.

Methods

SAR-COVID is a national, longitudinal and observational registry. Patients of ≥18 years old, with diagnosis of RA (ACR-EULAR criteria 2010) who had confirmed SARS-CoV-2 infection (RT-PCR or positive serology) were included between 13-8-20 and 31-7-21. Sociodemographic and clinical data, comorbidities, disease activity and treatment at the moment of the SARS-CoV-2 infection were collected. Additionally, infection symptoms, complications, medical interventions and treatments for COVID-19 were registered. Infection severity was assessed using the WHO-ordinal scale (WHO-OS)1. A cut-off value of ≥5 identified patients with severe COVID-19 and those who died.

Statistical analysis: Descriptive statistics. Chi2 or Fischer test, Student T test or Mann-Whitney and Kruskal Wallis or ANOVA, as appropriate. Multiple logistic regression model.

Results

A total of 801 patients were included, with a mean age of 53.1 ± 12.9 years, most of them were female (84.5%) and the median (m) disease duration was 8 years (IQR 4-14). One third were in remission and 46.4% had comorbidities, being the most frequent, hypertension (26.9 %), dyslipidemia (13.5 %), obesity (13.4 %) and diabetes (8.9%). Moreover, 3.2% had interstitial lung disease (ILD) associated with RA. At SARS-CoV-2 diagnosis, 42.5% were receiving glucocorticoids (GC), 73.9% conventional (c) disease modifying antirheumatic drugs (DMARD), 24% biologic (b) DMARD and 9.1% targeted synthetic (ts) DMARD. Among bDMARD, the most frequently used were TNF inhibitors (17%), followed by abatacept (2.8%), IL-6 inhibitors (2.4%) and rituximab (RTX) (2.1%). During the SARS-CoV-2 infection, 95.8% had symptoms, 27% required hospitalization, 7.9% presented complications and 4.4% died due to COVID-19. Severe disease and death (WHO-OS≥5) was present in 7.5% of the patients. They were older (62.9±12.5 vs 52.2±12.7, p<0.001), and they had more frequently ILD (18.5% vs 2%, p<0.001), comorbidities (82.5% vs 43.7%, p<0.001), ≥2 comorbidities (60.3% vs 25.8%, p<0.001), treatment with GC (61% vs 40.7%, p=0.04) and RTX (8.3% vs 1.6%, p=0.007). Conversely, the use of cDMARD and TNF inhibitors was more frequent in patients with WHO-OS<5, nevertheless this difference was not significant. Disease activity was comparable between groups. In multivariable analysis, older age, the presence of diabetes, ILD, the use of GC and RTX were significantly associated with WHO-OS≥5 (Figure 1). Furthermore, older age (65.7±10.8 vs 52.4±12.8, p<0.001), the presence of comorbidities (87.9% vs 44.7%, p<0.001), chronic obstructive pulmonary disease (21.9% vs 5.2%, p=0.002), diabetes (30.3% vs 7.9%, p<0.001), hypertension (57.6% vs 25.6%, p<0.001), cardiovascular disease (15.6% vs 3.2%, p=0.005), cancer (9.1% vs 1.3%, p=0.001), ILD (23.3% vs 2.4%, p<0.001) and the use of GC (61.8% vs 41.4%, p=0.02) were associated with mortality. Older age [OR 1.1 IC95% 1.06-1.13] and the use of GC 5-10 mg/day [OR 4.6 IC95% 1.8-11.6] remained significantly associated with death due to COVID-19.

Figure 1.

Factors associated with severe disease and death due to COVID-19 (WHO-OS≥5) in patients with rheumatoid arthritis. Multivariable analysis. (ref.: reference; PDN: prednisone; OR: odds ratio; CI: confidence interval)

Conclusion

Treatment with RTX and GC, as well as older age, the presence of diabetes and ILD were associated with poor COVID-19 outcomes in this national cohort of patients with RA. Older patients and those taking GC had a higher mortality rate.

References

[1]World Health Organization coronavirus disease (COVID-19) Therapeutic Trial Synopsis Draft 2020.

Disclosure of Interests

None declared

Myositis-specific antibodies and clinical characteristics in patients with autoimmune inflammatory myopathies: reported by the Argentine Registry of Inflammatory Myopathies of the Argentine Society of Rheumatology

INTRODUCTION/OBJECTIVES

To describe clinical features in patients with inflammatory myopathies (IMs) from the Argentine Registry of Inflammatory Myopathies, and their relationship with myositis-specific antibodies (MSAs).

METHODS

This cross-sectional study included 360 adult patients with dermatomyositis (DM), polymyositis (PM), and inclusion body myositis. Demographics, clinical, and serological characteristics were retrospectively recorded (2016-2019). MSAs were determined by immunoblotting. Patients who were positive for anti-Jo-1, Mi-2, and MDA5 were compared against a group of patients, taken as reference group, who were negative for all MSAs.

RESULTS

Women 72%, median age at diagnosis was 47.3 years (18-82). The most frequent subtypes were DM (43.9%) followed by PM (30%).The most frequent MSAs were anti-Jo-1 (51/317), 16.1%; MDA5 (12/111), 10.8%, and Mi-2 (23/226), 10.2%. Anti-Jo-1 was associated (p < 0.05) with a higher frequency of chronic disease course, interstitial lung disease (ILD), arthritis, and mechanic's hands. Anti-Mi-2 was found in patients who had higher frequency of skin manifestations and higher CK values (p < 0.001). Patients with anti-MDA5 had normal or low CK levels. Anti-MDA5 was associated (p < 0.05) with skin manifestations, arthritis, and ILD. The rest of MSAs had frequencies lower than 8%. Anti-TIF1ϒ was found in eight DM patients and one had cancer. Anti-SRP was found in seven patients who had PM and elevated CK.

CONCLUSION

Anti-Jo-1 was the most frequent MSA, and was associated with ILD; MDA5 was associated with CADM and ILD, and Mi-2, with classical DM. Despite the different prevalence with respect to other cohorts, the clinical characteristics for each MSA group were similar to the data reported in other studies. Key Points • This study describes the prevalence of MSAs in the Argentine Registry of IMs. • Anti-Jo-1 and anti-MDA5 were associated with ILD. • Anti-Mi-2 was the third most frequent MSA, associated with classical DM.