Prognostic value of anti-IFI16 autoantibodies in pulmonary arterial hypertension and mortality in patients with systemic sclerosis / Valor pronóstico de los autoanticuerpos anti-IFI16 en la hipertensión arterial pulmonar y en la mortalidad en los pacientes con esclerodermia sistémica

Objectives: To determine the diagnostic value of anti-interferon gamma inducible protein 16 (IFI16) autoantibodies in systemic sclerosis (SSc) patients negative for all tested SSc-specific autoantibodies (SSc-seronegative patients) and to evaluate the clinical significance of these autoantibodies, whether isolated or in the presence of anti-centromere autoantibodies (ACA). Methods: Overall, 58 SSc-seronegative and 66 ACA-positive patients were included in the study. All patients were tested for anti-IFI16 autoantibodies by an in-house direct ELISA. Associations between clinical parameters and anti-IFI16 autoantibodies were analysed. Results: Overall, 17.2% of SSc-seronegative and 39.4% of ACA-positive patients were positive for anti-IFI16 autoantibodies. Anti-IFI16 autoantibodies were found only in patients within the limited cutaneous SSc (lcSSc) subset. A positive association between anti-IFI16 positivity and isolated pulmonary arterial hypertension (PAH) was found (odds ratio [OR]=5.07; p=0.014) even after adjusting for ACA status (OR=4.99; p=0.019). Anti-IFI16-positive patients were found to have poorer overall survival than negative patients (p=0.032). Cumulative survival rates at 10, 20 and 30 years were 96.9%, 92.5% and 68.7% for anti-IFI16-positive patients vs. 98.8%, 97.0% and 90.3% for anti-IFI16-negative-patients, respectively. Anti-IFI16-positive patients also had worse overall survival than anti-IFI16-negative patients after adjusting for ACA status in the multivariate Cox analysis (hazard ratio [HR]=3.21; p=0.043). Conclusion: Anti-IFI16 autoantibodies were associated with isolated PAH and poorer overall survival. Anti-IFI16 autoantibodies could be used as a supplementary marker of lcSSc in SSc-seronegative patients and for identifying ACA-positive patients with worse clinical outcome. (AU)

Objetivos: Determinar el valor diagnóstico de los autoanticuerpos anti-interferon gamma inducible protein 16 (IFI16) en los pacientes con esclerodermia sistémica (SSc) negativos para todos los autoanticuerpos específicos de SSc (pacientes SSc seronegativos) y evaluar el significado clínico de estos autoanticuerpos, aislados o en combinación con autoanticuerpos anticentrómero (ACA). Métodos: Se incluyeron 58 pacientes SSc seronegativos y 66 pacientes ACA positivos. Todos los pacientes se testaron para los autoanticuerpos anti-IFI16 mediante un ELISA directo «in-house». Las asociaciones entre parámetros clínicos y los autoanticuerpos anti-IFI16 fueron analizadas. Resultados: En total, el 17,2% de los pacientes SSc seronegativos y el 39,4% de los pacientes ACA positivos fueron positivos para anti-IFI16. Los autoanticuerpos anti-IFI16 se detectaron solamente en los pacientes con la forma limitada cutánea de SSc (lcSSc). Se encontró una asociación entre la positividad de anti-IFI16 y la hipertensión arterial pulmonar (HAP) aislada (odds ratio [OR]: 5,07; p=0,014), incluso cuando se ajustó el análisis a la presencia o ausencia de ACA (OR: 4,99; p=0,019). Los pacientes anti-IFI16 positivos mostraron una peor supervivencia general que los pacientes negativos (p=0,032). Las ratios de supervivencia acumulada a 10, 20 y 30 años fueron respectivamente del 96,9, 92,5 y 68,7% para los pacientes anti-IFI16 positivos frente al 98,8, 97,0 y 90,3% para los anti-IFI16 negativos. Los pacientes anti-IFI16 positivos también tenían una supervivencia general menor que los pacientes anti-IFI16 negativos tras ajustar para la presencia o ausencia de ACA mediante análisis multivariado de Cox (hazard ratio [HR]: 3,21; p=0,043)... (AU)

Prognostic value of anti-IFI16 autoantibodies in pulmonary arterial hypertension and mortality in patients with systemic sclerosis.

OBJECTIVES: To determine the diagnostic value of anti-interferon gamma inducible protein 16 (IFI16) autoantibodies in systemic sclerosis (SSc) patients negative for all tested SSc-specific autoantibodies (SSc-seronegative patients) and to evaluate the clinical significance of these autoantibodies, whether isolated or in the presence of anti-centromere autoantibodies (ACA). METHODS: Overall, 58 SSc-seronegative and 66 ACA-positive patients were included in the study. All patients were tested for anti-IFI16 autoantibodies by an in-house direct ELISA. Associations between clinical parameters and anti-IFI16 autoantibodies were analysed. RESULTS: Overall, 17.2% of SSc-seronegative and 39.4% of ACA-positive patients were positive for anti-IFI16 autoantibodies. Anti-IFI16 autoantibodies were found only in patients within the limited cutaneous SSc (lcSSc) subset. A positive association between anti-IFI16 positivity and isolated pulmonary arterial hypertension (PAH) was found (odds ratio [OR]=5.07; p=0.014) even after adjusting for ACA status (OR=4.99; p=0.019). Anti-IFI16-positive patients were found to have poorer overall survival than negative patients (p=0.032). Cumulative survival rates at 10, 20 and 30 years were 96.9%, 92.5% and 68.7% for anti-IFI16-positive patients vs. 98.8%, 97.0% and 90.3% for anti-IFI16-negative-patients, respectively. Anti-IFI16-positive patients also had worse overall survival than anti-IFI16-negative patients after adjusting for ACA status in the multivariate Cox analysis (hazard ratio [HR]=3.21; p=0.043). CONCLUSION: Anti-IFI16 autoantibodies were associated with isolated PAH and poorer overall survival. Anti-IFI16 autoantibodies could be used as a supplementary marker of lcSSc in SSc-seronegative patients and for identifying ACA-positive patients with worse clinical outcome.

Anti-nuclear valosin-containing protein-like autoantibody is associated with calcinosis and higher risk of cancer in systemic sclerosis.

OBJECTIVES: Systemic sclerosis (SSc)-specific autoantibodies allow the diagnosis and predict the prognosis of SSc patients with different clinical characteristics. The aim of this study was to describe new SSc-related autoantibodies by a novel protein immunoprecipitation (IP) assay. METHODS: Serum samples and clinical data were collected from 307 SSc patients. Antinuclear autoantibodies were tested in all patients by indirect immunofluorescence (IIF) on HEp-2 cells. SSc-specific autoantibodies were evaluated with a commercial immunoblot and chemiluminescence immunoassay, and traditional RNA-IP. Patients negative for all these autoantibodies (n = 51) were further tested with a non-radioactive protein IP assay. Protein bands detected on SDS-PAGE were then analysed by mass spectrometry (MS) and confirmed by western blot (WB). Additional 56 patients with nucleolar pattern by IIF were tested by protein IP-WB. RESULTS: Five patients who underwent protein IP testing showed a 110-115kDa molecular weight band on SDS-PAGE and a homogeneous nucleolar pattern by IIF. MS identified the bands as nuclear valosin-containing protein-like (NVL). An additional positive patient was detected by IP-WB. As compared with the remaining 101 negative patients, anti-NVL positive patients showed a greater prevalence of calcinosis (100% vs 18.9%, p< 0.001), and cancer (66.7% vs 8.9%, p= 0.002), with a particular association with synchronous cancer (OR = 16.3; p= 0.024). CONCLUSION: We identified NVL as a new autoantibody target by a novel protein IP assay in SSc patients with a homogeneous nucleolar IIF pattern, testing negative for all known SSc-specific autoantibodies by commercial assays and RNA IP. Anti-NVL identifies a new clinical phenotype, characterized by calcinosis and cancer.

Nailfold videocapillaroscopy patterns in systemic sclerosis: implications for cutaneous subsets, disease features and prognostic value for survival.

OBJECTIVES: To assess the associations and prognostic value of scleroderma patterns by nailfold videocapillaroscopy (NVC) in patients with systemic sclerosis (SSc) and cutaneous subsets. METHODS: At baseline, 1356 SSc patients from the RESCLE registry were compared according to the scleroderma pattern as Late pattern and non-Late pattern, which included Early and Active patterns. Patient characteristics, disease features, survival time and causes of death were analysed. RESULTS: Late pattern was identified in 540 (39.8%), and non-Late pattern in 816 (60.2%) patients (88% women; 987 lcSSc/251 dcSSc). Late pattern was associated to dcSSc (OR=1.96; p<0.001), interstitial lung disease (ILD) (OR=1.29; p=0.031), and scleroderma renal crisis (OR=3.46; p<0.001). Once the cutaneous subset was disregarded in an alternative analysis, both digital ulcers (DU) (OR=1.29; p<0.037) and anti-topoisomerase I antibodies (OR=1.39; p< 0.036) emerged associated with the Late pattern. By cutaneous subsets, associations with Late pattern were: (1) in dcSSc, acro-osteolysis (OR=2.13; p=0.022), and systolic pulmonary artery pressure >40 mmHg by Doppler echocardiogram (OR=2.24; p<0.001); and (2) in lcSSc, ILD (OR=1.38; p=0.028). Survival was reduced in dcSSc with Late pattern compared to non-Late pattern (p=0.049). Risk factors for SSc mortality in multivariate regression Cox analysis were age at diagnosis (HR=1.03; p<0.001), dcSSc (HR=2.48; p<0.001), DU (HR=1.38; p=0.046), ILD (HR=2.81; p<0.001), and pulmonary arterial hypertension (HR=1.99; p<0.001). CONCLUSIONS: SSc patients with Late pattern more frequently present dcSSc and develop more fibrotic and vascular manifestations. Advanced microangiopathy by NVC identifies dcSSc patients at risk of reduced survival due to SSc-related causes.

Anti-U11/U12 Antibodies as a Rare but Important Biomarker in Patients with Systemic Sclerosis: A Narrative Review.

Anti-nuclear (ANA) are present in approximately 90% of systemic sclerosis (SSc) patients and are key biomarkers in supporting the diagnosis and determining the prognosis of this disease. In addition to the classification criteria autoantibodies for SSc [i.e., anti-centromere, anti-topoisomerase I (Scl-70), anti-RNA polymerase III], other autoantibodies have been associated with important SSc phenotypes. Among them, anti-U11/U12 ribonucleoprotein (RNP) antibodies, also known as anti-RNPC-3, were first reported in a patient with SSc, but very little is known about their association and clinical utility. The U11/U12 RNP macromolecular complex consists of several proteins involved in alternative mRNA splicing. More recent studies demonstrated associations of anti-anti-U11/U12 antibodies with SSc and severe pulmonary fibrosis as well as with moderate to severe gastrointestinal dysmotility. Lastly, anti-U11/U12 autoantibodies have been strongly associated with malignancy in SSc patients. Here, we aimed to summarize the knowledge of anti-U11/U12/RNPC-3 antibodies in SSc, including their seroclinical associations in a narrative literature review.

Standardized incidence ratios and risk factors for cancer in patients with systemic sclerosis: Data from the Spanish Scleroderma Registry (RESCLE).

AIM: Patients with systemic sclerosis (SSc) are at increased risk of cancer, a growing cause of non-SSc-related death among these patients. We analyzed the increased cancer risk among Spanish patients with SSc using standardized incidence ratios (SIRs) and identified independent cancer risk factors in this population. MATERIAL AND METHODS: Spanish Scleroderma Registry data were analyzed to determine the demographic characteristics of patients with SSc, and logistic regression was used to identify cancer risk factors. SIRs with 95% confidence intervals (CIs) relative to the general Spanish population were calculated. RESULTS: Of 1930 patients with SSc, 206 had cancer, most commonly breast, lung, hematological, and colorectal cancers. Patients with SSc had increased risks of overall cancer (SIR 1.48, 95% CI 1.36-1.60; P < 0.001), and of lung (SIR 2.22, 95% CI 1.77-2.73; P < 0.001), breast (SIR 1.31, 95% CI 1.10-1.54; P = 0.003), and hematological (SIR 2.03, 95% CI 1.52-2.62; P < 0.001) cancers. Cancer was associated with older age at SSc onset (odds ratio [OR] 1.22, 95% CI 1.01-1.03; P < 0.001), the presence of primary biliary cholangitis (OR 2.35, 95% CI 1.18-4.68; P = 0.015) and forced vital capacity <70% (OR 1.8, 95% CI 1.24-2.70; P = 0.002). The presence of anticentromere antibodies lowered the risk of cancer (OR 0.66, 95% CI 0.45-0.97; P = 0.036). CONCLUSIONS: Spanish patients with SSc had an increased cancer risk compared with the general population. Some characteristics, including specific autoantibodies, may be related to this increased risk.

Left ventricular diastolic dysfunction in systemic sclerosis: Clinical, immunological and survival differences in the Spanish RESCLE registry.

OBJECTIVES: Left ventricular diastolic dysfunction (LVDD) remains poorly studied in Systemic Sclerosis (SSc). To determine the prevalence and to define factors associated with LVDD and survival in a large cohort of patients with SSc. METHODS: An observational study was conducted with data from the multicentre Spanish Scleroderma Registry (RESCLE) to identify factors associated with LVDD and estimate survival. RESULTS: Out of 1517 patients, 319 (21.0%) had LVDD. The subset of sine scleroderma SSc was associated to LVDD (14.7% vs. 10.6%, p =0.048), whilst diffuse cutaneous SSc was more prevalent in non-LVDD (16.0 % vs. 21.2%, p =0.041). Multivariable analysis identified that LVDD was associated with older age at diagnosis of SSc (OR 1.05; 95% CI 1.04 to 1.06), longer time from diagnosis (OR 1.04; 95% CI 1.03 to 1.06), presence of telangiectasia (OR 1.42; 95% CI 1.08 to 1.88), treatment with calcium channel blockers (CCB) (OR 1.51; 95% CI 1.16 to 1.96), and inversely related to angiotensin-converting-enzyme inhibitors (ACEi) use (OR 0.59; 95% CI 0.44 to 0.80). SSc patients with LVDD had increased mortality (23.8 vs. 17.4%, p =0.010) and shortened survival from the first SSc symptom (p =0.040), even though it was not found to be an independent risk factor for death. CONCLUSIONS: LVDD is relatively common in SSc patients, and it is associated with worst prognosis, older age, longer time from diagnosis of SSc, presence of telangiectasia and vasodilator treatment.

Anti-RNPC-3 antibody predicts poor prognosis in patients with interstitial lung disease associated to systemic sclerosis.

OBJECTIVE: To analyse the prevalence, the clinical characteristics, the overall survival and the event-free survival (EFS) of SSc patients who express anti-U11/U12 RNP (RNPC-3) antibodies. METHODS: A total of 447 SSc patients from Barcelona (n = 286) and Milan (n = 161) were selected. All samples were tested using a particle-based multi-analyte technology. We compared anti-RNPC-3 positive and negative patients. Epidemiological, clinical features and survival were analysed. End-stage lung disease (ESLD) was defined if the patient developed forced vital capacity <50% of predicted, needed oxygen therapy or lung transplantation. EFS was defined as the period of time free of either ESLD or death. RESULTS: Nineteen of 447 (4.3%) patients had anti-RNPC-3 antibodies and interstitial lung disease (ILD) was more frequent (11, 57.9% vs 144, 33.6%, P =0.030) in individuals with anti-RNPC-3 antibodies. More patients reached ESLD in the positive group (7, 36.8% vs 74, 17.3%, P = 0.006), and a higher use of non-glucocorticoid immunosuppressive drugs was observed (11, 57.9% vs 130, 30.4%, P = 0.012). Anti-RNPC-3 positive patients had lower EFS, both in the total cohort (log-rank P =0.001), as well as in patients with ILD (log-rank P = 0.002). In multivariate Cox regression analysis, diffuse cutaneous subtype, age at onset, the presence of ILD or pulmonary arterial hypertension and the expression of anti-RNPC-3 positivity or anti-topo I were independently associated with worse EFS. CONCLUSION: The presence of anti-RNPC-3 was associated with higher frequency of ILD and either ESLD or death. These data suggest anti-RNPC-3 is an independent poor prognosis antibody in SSc, especially if ILD is also present.

Severe osteomalacia with multiple insufficiency fractures secondary to intravenous iron therapy in a patient with Rendu-Osler-Weber syndrome.

SUMMARY: This case report describes a 65-year-old man with a Rendu-Osler-Weber syndrome with secondary chronic anaemia, who received multiple intravenous (IV) iron infusions and sustained diffuse bone pain secondary to multiple insufficiency fractures. Laboratory study confirmed fibroblast growth factor 23 (FGF-23)-mediated hypophosphatemia as the main cause of a severe osteomalacia induced by ferric carboxymaltose (FCM).After 3 months or oral phosphate replacement and switching to iron sucrose, serum phosphate levels were normalized and patient improved clinically. INTRODUCTION: Some drugs can induce asymptomatic hypophosphatemia, which if sustained, can lead to a severe osteomalacia with multiple skeletal fractures. This complication has also been described with IV iron therapy. METHODS: This case report describes a patient with Rendu-Osler-Weber syndrome with chronic iron deficiency anaemia, recurrently treated with FCM, who developed a severe osteomalacia with multiple skeletal fractures. RESULTS: Laboratory study showed hypophosphatemia, with high ALP and high FGF-23. Images studies confirmed bone mass loss and multiple insufficiency fractures. A Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (18F-FDG PET/CT) did not show hidden tumor, so a diagnosis of FCM-induced hypophosphatemic osteomalacia was performed. Phosphate replacement improved clinical symptoms of the patient. CONCLUSION: Intravenous iron therapy, mainly FCM form, can cause hypophosphatemia, and in some cases induce a severe osteomalacia with multiple fractures, so it seems advisable to monitor serum phosphate levels in high risk patients, as those who receive repeated dose.

Clinical features of systemic sclerosis patients with anti-RNA polymerase III antibody in a single centre in Spain.

OBJECTIVES: To evaluate the clinical features and survival of patients with positive anti-RNA polymerase III (anti-RNAP III) in a Spanish single centre. METHODS: We analysed 221 patients with SSc according to LeRoy and Medsger criteria. Twenty-six patients with positivity for anti-RNAP III antibodies were compared with 195 negative patients. Epidemiological, clinical, immunological features and survival were analysed. RESULTS: In patients with anti-RNAP III positivity diffuse cutaneous SSc (dcSSc) subset was the most prevalent (20, 76.9% vs. 35, 17.9%, p < 0.001), with shorter diagnosis delay (4.11 ± 7.34 years vs. 6.77 ± 9.22 years, p = 0.005). Patients with anti-RNAP III antibodies had higher frequency of arterial hypertension (13, 50% vs. 55, 28.2%, p = 0.024), scleroderma renal crisis (SRC) (3, 11.5% vs. 3, 1.5%, p = 0.023), arthritis (9, 34.6% vs. 35, 17.9%, p = 0.046), tendon friction rubs (4, 15.4% vs. 1, 0.5%, p = 0.001) and contractures (5, 19.2% vs. 10, 5.1%, p = 0.02). There were no differences found in the presence of cancer or in global survival. In the multivariate survival analysis, severe interstitial lung disease (ILD) (HR: 8.61, 95%CI 3.40 - 21.81), pulmonary arterial hypertension (PAH) (HR: 4.05, 95%CI 1.42 - 11.61) and SRC (HR: 17.27, 95%CI 3.36 - 88.97) were the only factors associated with poor prognosis. CONCLUSIONS: In this cohort anti-RNAP III antibodies are related with dcSSc subset, shorter diagnostic delay and higher prevalence of musculoskeletal involvement, arterial hypertension and SRC. ILD, PAH and SRC were independent prognostic factors.

Quantitative videocapillaroscopy correlates with functional respiratory parameters: a clue for vasculopathy as a pathogenic mechanism for lung injury in systemic sclerosis.

BACKGROUND: To determine whether lung involvement is related to microvascular perturbations, nailfold videocapillaroscopy (NVC) was performed in patients with systemic sclerosis (SSc). METHODS: A cross-sectional study was consecutively accomplished in 152 SSc patients. NVC, a pulmonary function test and echocardiography were undergone within a 3-month period. Finally, 134 patients with at least eight NVC (200× magnification) images were selected for quantitative and qualitative examinations. RESULTS: Patients with interstitial lung disease presented lower median capillary density (4.86/mm vs 5.88/mm, p = 0.005) and higher median of neoangiogenesis (0.56/mm vs 0.31/mm, p = 0.005). A higher quantity of neoangiogenesis capillaries was found in patients with pulmonary arterial hypertension (0.70/mm vs 0.33/mm, p = 0.008). Multivariate linear regression analysis established a correlation between neoangiogenesis and decreased forced vital capacity (FVC) (p < 0.001): for each capillary with neoangiogenesis visualized on average per 1 mm, FVC was 7.3% reduced. In qualitative NVC, a late pattern as defined by Cutolo was also associated with lower FVC (p = 0.018). The number of giant capillaries was associated with reduced diffusion capacity of the lung for carbon monoxide (DLCO) (p = 0.016); for each giant capillary per 1 mm, DLCO was 11.8% diminished. CONCLUSIONS: A good correlation was observed between distinctive quantitative and qualitative NVC features with lung functional parameters such as FVC and DLCO. It is suggested that vasculopathy could play a role in SSc lung involvement.

High sensitivity and negative predictive value of the DETECT algorithm for an early diagnosis of pulmonary arterial hypertension in systemic sclerosis: application in a single center.

BACKGROUND: Pulmonary arterial hypertension (PAH) is one of the most relevant causes of death in systemic sclerosis. The aims of this study were to analyse the recently published DETECT algorithm comparing it with European Society of Cardiology/European Respiratory Society (ESC/ERS) 2009 guidelines: as screening of PAH; (2) identifying median pulmonary arterial pressure (mPAP) ≥21 mmHg; and (3) determining any group of pulmonary hypertension (PH). METHODS: Eighty-three patients fulfilling LeRoy's systemic sclerosis diagnostic criteria with at least right heart catheterization were studied retrospectively. Clinical data, serological biomarkers, echocardiographic and hemodynamic features were collected. SPSS 20.0 was used for statistical analysis. RESULTS: According to right heart catheterization findings, 35 patients with PAH and 28 with no PH met the standards for DETECT algorithm analysis: 27.0% of patients presented with functional class III/IV. Applying DETECT, the sensitivity was 100%, specificity 42.9%, the positive predictive value 68.6% and the negative predictive value 100%, whereas employing the ESC/ERS guidelines these were 91.4%, 85.7%, 88.9% and 89.3%, respectively. There were no missed diagnoses of PAH using DETECT compared with three patients missed (8.5%) using ESC/ERS guidelines. The DETECT algorithm also showed greater sensitivity and negative predictive value to identify patients with mPAP ≥21 mmHg or with any type of PH. CONCLUSIONS: The DETECT algorithm is confirmed as an excellent screening method due to its high sensitivity and negative predictive value, minimizing missed diagnosis of PAH. DETECT would be accurate either for early diagnosis of borderline mPAP or any group of PH.

Novel risk factors related to cancer in scleroderma.

OBJECTIVE: Emerging data have shown an increased risk of malignancy among patients diagnosed with systemic sclerosis (SSc) so identification of risk factors linking both disorders might have prognostic implications. The aim of this study was to assess the clinical and treatment-related risk factors for cancer in a single-center cohort of patients with SSc. METHODS: Demographic, clinical, capillaroscopic, immunological and treatment-related data from 432 consecutive SSc patients were retrospectively analyzed. Variables that reached significant association in the univariate analysis were entered into a logistic regression in order to identify independent risk factors for cancer. RESULTS: Malignancy was diagnosed in 53 patients (12.2%). Fifty-eight neoplasms were identified, among which breast (n=15), lung (n=10) and hematologic (n=9) malignancies were the most prevalent. In 19 patients the diagnosis of both scleroderma and tumour was made in <3years apart. Cancer significantly decreased the probability of survival (OR=2.61; 95%CI 1.46-4.69; p=0.001). No association with age, sex, smoking, cutaneous subset or RNA polymerase-III antibodies was found. However, risk of cancer was directly associated with the presence of anti-PM/Scl antibodies (OR=3.90; 95%CI 1.31-11.61; p=0.014), and inversely related to aspirin use (OR=0.33; 95%CI 0.12-0.90; p=0.031), which remained as independent risk factors for cancer on multivariate analysis. CONCLUSIONS: PM/Scl antibodies seem to be associated with a higher risk of cancer in scleroderma. In contrast, the use of aspirin is related to a lower risk of cancer in our series. More studies are needed to ascertain the role of anti PM/Scl antibodies and aspirin in the development of malignancy among patients with SSc.

Mixed Connective Tissue Disease and Epitope Spreading: An Historical Cohort Study.

OBJECTIVES: Mixed connective tissue disease (MCTD) is characterized by the presence of anti-U1-snRNP autoantibodies and a variable set of associated clinical features. Some MCTD patients test positive over time to autoantibodies against Sm, proteins spatially related with U1-snRNP. This situation has been attributed to expanding of the autoimmune response by a phenomenon known as epitope spreading. Our aim was to study the frequency of this phenomenon in MCTD patients and the specific clinical features of those with epitope spreading. METHODS: All anti-U1-RNP-positive patients (2010-2015) were retrospectively reviewed, and those meeting the MCTD criteria were included in the study. Patients showing epitope spreading were compared with the remainder of the MCTD cohort. In addition, the clinical features of patients with epitope spreading were compared before and after the phenomenon occurred. RESULTS: Among 72 anti-U1-RNP-positive patients, 40 (37 women) were diagnosed with MCTD. Thirteen MCTD patients (43%) presented epitope spreading, mainly during the first 2 years after the diagnosis of the disease (median, 1.4 years). Patients with epitope spreading had a significantly lower prevalence of skin sclerosis (0% vs. 44%, P = 0.004) and a greater prevalence of interstitial lung disease (46% vs. 15%, P = 0.05) than those without. Arthritis (92% vs. 25%, P = 0.02) and muscle involvement (67% vs. 17%, P = 0.02) were less frequent after epitope spreading had occurred. CONCLUSION: Epitope spreading is common in MCTD, occurring early after the diagnosis. The clinical manifestations in patients with this phenomenon differ from those without, and their clinical features change after the immunological phenomenon has occurred.

Hipo como forma de presentación de una disección de aorta / Hiccups as an onset form of aortic dissection

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Angioma de células del litoral, una causa infrecuente de síndrome constitucional / Littoral cell angioma. An uncommon cause of constitutional syndrome

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