Multicenter lupus register from Argentina, the RELESSAR database: Influence of ethnicity on disease phenotype.

OBJECTIVE: The objective is to describe the main characteristics of patients with systemic lupus erythematosus (SLE) in Argentina and to examine the influence of ethnicity on the expression of the disease. PATIENTS AND METHODS: RELESSAR is a multicentre register carried out by 106 researchers from 67 rheumatologic Argentine centres. It is a cross-sectional study of SLE (1982/1997 ACR) patients. RELESSAR electronic database includes demographic, cumulative SLE manifestations, SELENA-SLEDAI, SLICC-SDI, Katz's severity and Charlson's comorbidity indexes and treatment patterns. RESULTS: We included 1,610 patients, 91.7% were female with a median age at diagnosis of 28.1 ± 12.8; 96.2% met ≥4 ACR 1982/97 criteria. Frequent manifestations were arthritis (83.5%), malar rash (79.5%), photosensitivity (75.3%), haematological (63.8%) and renal disease (47.4%), antinuclear antibodies (96%), anti-dsDNA (66.5%) and anti-Smith antibodies (29%). The mean Selena-SLEDAI score at last visit was 3.18 (SD 4.3) and mean SDI was 1 (SD 1.3). The accumulated treatments most frequently used were antimalarials (90.4%), corticosteroids (90%), azathioprine (31.8%), intravenous cyclophosphamide (30.2%), mycophenolate mofetil or mycophenolic acid (24.5%), methotrexate (19.3%), belimumab 5.3% and rituximab 5.1%. Refractory lupus was diagnosed in 9.3% of the cases. The main causes of death were lupus activity (25.0%), activity and concomitant infections (25.0%), infections (18.2%), vascular disease (13.6%) and cancer (4.5%). Mortality was associated with higher SLEDAI, Katz, damage indexes and comorbidities. Of the 1610 patients included, 44.6% were Caucasian, 44.5% Mestizo, 8.1% Amerindian and 1.2% Afro-Latin American. Mestizo patients had higher male representation, low socioeconomic status, more inadequate medical coverage, fewer formal years of education and shorter disease duration. Polyadenopathies and Raynaud's phenomenon were more frequent in Caucasians. In the logistic regression analysis higher damage index (OR 1.28, CI 95% 1.02-1.61, p = 0.03) remained associated to mestizo ethnicity. CONCLUSIONS: This study represents the largest number of adult patients with SLE studied in Argentina. Caucasian patients were differentiated by having Raynaud's phenomenon and polyadenopathy more frequently, while patients of Mestizo origin had higher damage indexes.

Validation and adaptation of the Spanish version of the systemic lupus activity questionnaire (S-SLAQ) in an Argentinean population.

OBJECTIVES: To validate the systemic lupus activity questionnaire (SLAQ) in Spanish language. METHODS: The SLAQ questionnaire was translated and adapted in Spanish. Consecutive SLE patients from 8 centers in Argentina were included. A rheumatologist completed a Systemic Lupus Activity Measure (SLAM), Systemic Lupus Erythematosus Disease Activity Index (SLEDAI)-2K, and a physician's assessment. Reliability was assessed by internal consistency (Cronbach's alpha), stability by test-retest reliability (intraclass correlation coefficient), and construct validity by evaluating the correlation with clinically relevant scores. Sensitivity and specificity for clinically significant disease activity (SLEDAI ≥6) of different S-SLAQ cut-off points were evaluated. RESULTS: We included 97 patients ((93% female, mean age: 40 years (SD14.7)). Internal consistency was excellent (Cronbach's alpha = 0.84, p < 0.001), and the intraclass correlation coefficient was 0.95 (p < 0.001). Mean score of S-SLAQ was 8.2 (SD 7.31). Correlation of S-SLAQ was moderate with Patient NRS (r= 0.63 p< 0.001), weak with SLAM-no lab (r = 0.42, p <0.001) and SLAM (r = 0.38, p < 0.0001), and very weak with SLEDAI-2K (r = 0.15, p =0.1394). Using the S-SLAQ cutoff of five points, the sensitivity was 72.2% and specificity was 37.9%, for clinically significant disease activity. CONCLUSIONS: The S-SLAQ showed good validity and reliability. A good correlation, similar to the original instrument, was observed with patient´s global disease activity. No correlation was found between S-SLAQ and gold standard disease activity measures like SLEDAI-2K and SLAM. The S-SLAQ cutoff point of 5 showed a good sensitivity to identify the active SLE population and therefore could be an appropriate screening instrument for disease activity in clinical and epidemiological studies.

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.

Autoantibodies in adult patients with idiopathic inflammatory myopathies in Buenos Aires.

The idiopathic inflammatory myopathies(IIM) are a heterogeneous group of diseases of the skeletal muscle. On the basis of clinical, serologic and histological differences, they are classified in dermatomyositis (DM), polymyositis (PM), inclusion body myositis and immunomediated necrotizing myopathy. Autoantibodies directed against nuclear and cytoplasmic antigens are present with variable frequencies among studies. Myositis-specific antibodies (MSAs) are useful in IIM because they contribute to the diagnosis, help to identify different clinical subsets, and have prognostic value. This study aimed to explore the frequency of autoantibodies, especially MSAs, and their relationship with clinical features in adult patients with DM, PM and overlap syndrome. Medical records were reviewed. Myositis-associated antibodies (non-specific) and MSAs (anti Jo-1, PL-7, PL-12, Mi-2 and SRP) were measured using commercial kits. Twelve patients had MSAs, an overall frequency similar to those of international series, but PL-12 and Mi-2 were more frequent than Jo-1, which is the most frequently observed elsewhere. All five patients with Mi-2 had classical DM with a favorable response to treatment. Interstitial pneumonia (n: 4) and/or treatment-refractory disease (n: 3) were found in the presence of anti-PL-12, alone or associated with anti-SRP and/or Jo-1. In conclusion, the coexistence of AEM, a rare finding, was found in three patients. The presence of MSAs aided to the diagnosis of IIM, in particular in those patients without available or conclusive biopsy results.

Autoantibodies in adult patients with idiopathic inflammatory myopathies in Buenos Aires

The idiopathic inflammatory myopathies(IIM) are a heterogeneous group of diseases of the skeletal muscle. On the basis of clinical, serologic and histological differences, they are classified in dermatomyositis (DM), polymyositis (PM), inclusion body myositis and immunomediated necrotizing myopathy. Autoantibodies directed against nuclear and cytoplasmic antigens are present with variable frequencies among studies. Myositis-specific antibodies (MSAs) are useful in IIM because they contribute to the diagnosis, help to identify different clinical subsets, and have prognostic value. This study aimed to explore the frequency of autoantibodies, especially MSAs, and their relationship with clinical features in adult patients with DM, PM and overlap syndrome. Medical records were reviewed. Myositis-associated antibodies (non-specific) and MSAs (anti Jo-1, PL-7, PL-12, Mi-2 and SRP) were measured using commercial kits. Twelve patients had MSAs, an overall frequency similar to those of international series, but PL-12 and Mi-2 were more frequent than Jo-1, which is the most frequently observed elsewhere. All five patients with Mi-2 had classical DM with a favorable response to treatment. Interstitial pneumonia (n: 4) and/or treatment-refractory disease (n: 3) were found in the presence of anti-PL-12, alone or associated with anti-SRP and/or Jo-1. In conclusion, the coexistence of AEM, a rare finding, was found in three patients. The presence of MSAs aided to the diagnosis of IIM, in particular in those patients without available or conclusive biopsy results.

Las miopatías inflamatorias idiopáticas (MII) comprenden un grupo heterogéneo de enfermedades adquiridas del músculo esquelético. Según sus características clínicas, serológicas e histológicas se las clasifica en dermatomiositis (DM), polimiositis (PM), miopatía necrotizante autoinmune y miositis por cuerpos de inclusión. Los anticuerpos específicos de miositis (AEMs) contribuyen al diagnóstico, permiten distinguir formas clínicas y tienen valor pronóstico. Con el objetivo de explorar la frecuencia de autoanticuerpos, en particular AEMs, y su relación con las características clínicas de las MII del adulto, se revisaron las historias clínicas de 25 pacientes con DM, PM y síndromes de superposición, asistidos en nuestro centro entre 1999 y 2013. La presencia de autoanticuerpos asociados a miositis (no específicos) y AEMs (anti Jo-1, PL-7, PL-12, Mi-2, SRP) se investigó utilizando kits comerciales. Doce pacientes presentaron AEMs, frecuencia global similar a la encontrada en series internacionales, pero a diferencia de lo observado en otros países, anti-PL-12 y anti-Mi-2 fueron más frecuentes que anti-Jo-1. Los cinco pacientes con anti-Mi-2 tuvieron DM clásica y buena evolución clínica. Anti-PL-12, ya sea solo o asociado a anti-SRP y/o anti-Jo-1, estuvo presente en pacientes con neumonía intersticial (n:4) y/o enfermedad refractaria al tratamiento (n: 3). En conclusión, la coexistencia de AEM, hallazgo raro, se encontró en tres pacientes. La presencia de AEMSs contribuyó al diagnóstico de MII, en particular en aquellos casos sin resultados concluyentes de biopsia de músculo.