Clinical presentation, course, and prognosis of patients with mixed connective tissue disease: A multicenter retrospective cohort.

OBJECTIVES: The objective of this study is to better characterize the features and outcomes of a large population of patients with mixed connective tissue disease (MCTD). METHODS: We performed an observational retrospective multicenter cohort study in France. Patients who fulfilled at least one diagnostic criterion set for MCTD and none of the criteria for other differentiated CTD (dCTD) were included. RESULTS: Three hundred and thirty patients (88% females, median [interquartile range] age of 35 years [26-45]) were included. The diagnostic criteria of Sharp or Kasukawa were met by 97.3% and 93.3% of patients, respectively. None met other classification criteria without fulfilling Sharp or Kasukawa criteria. After a median follow-up of 8 (3-14) years, 149 (45.2%) patients achieved remission, 92 (27.9%) had interstitial lung disease, 25 (7.6%) had pulmonary hypertension, and 18 (5.6%) died. Eighty-five (25.8%) patients progressed to a dCTD, mainly systemic sclerosis (15.8%) or systemic lupus erythematosus (10.6%). Median duration between diagnosis and progression to a dCTD was 5 (2-11) years. The presence at MCTD diagnosis of an abnormal pattern on nailfold capillaroscopy (odds ratio [OR] = 2.44, 95% confidence interval [95%CI] [1.11-5.58]) and parotid swelling (OR = 3.86, 95%CI [1.31-11.4]) were statistically associated with progression to a dCTD. Patients who did not progress to a dCTD were more likely to achieve remission at the last follow-up (51.8% vs. 25.9%). CONCLUSIONS: This study shows that MCTD is a distinct entity that can be classified using either Kasukawa or Sharp criteria, and that only 25.8% of patients progress to a dCTD during follow-up.

Anti-U1RNP antibodies are associated with a distinct clinical phenotype and a worse survival in patients with systemic sclerosis.

OBJECTIVES: To clarify the impact of anti-U1RNP antibodies on the clinical features and prognosis of patients with SSc. METHODS: We conducted a monocentric case-control, retrospective, longitudinal study. For each patient with SSc and anti-U1RNP antibodies (SSc-RNP+), one patient with mixed connective tissue disease (MCTD) and 2 SSc patients without anti-U1RNP antibodies (SSc-RNP-) were matched for age, sex, and date of inclusion. RESULTS: Sixty-four SSc-RNP+ patients were compared to 128 SSc-RNP- and 64 MCTD patients. Compared to SSc-RNP-, SSc-RNP+ patients were more often of Afro-Caribbean origin (31.3% vs. 11%, p < 0.01), and more often had an overlap syndrome than SSc-RNP- patients (53.1 % vs. 22.7%, p < 0.0001), overlapping with Sjögren's syndrome (n = 23, 35.9%) and/or systemic lupus erythematosus (n = 19, 29.7%). SSc-RNP+ patients were distinctly different from MCTD patients but less often had joint involvement (p < 0.01). SSc-RNP+ patients more frequently developed interstitial lung disease (ILD) (73.4% vs. 55.5% vs. 31.3%, p < 0.05), pulmonary fibrosis (PF) (60.9% vs. 37.5% vs. 10.9%, p < 0.0001), SSc associated myopathy (29.7% vs. 6.3% vs. 7.8%, p < 0.0001), and kidney involvement (10.9% vs. 2.3% vs. 1.6%, p < 0.05). Over a 200-month follow-up period, SSc-RNP+ patients had worse overall survival (p < 0.05), worse survival without PF occurrence (p < 0.01), ILD or PF progression (p < 0.01 and p < 0.0001). CONCLUSIONS: In SSc patients, anti-U1RNP antibodies are associated with a higher incidence of overlap syndrome, a distinct clinical phenotype, and poorer survival compared to SSc-RNP- and MCTD patients. Our study suggests that SSc-RNP+ patients should be separated from MCTD patients and may constitute an enriched population for progressive lung disease.

Anti-survival motor neuron complex antibodies as a novel biomarker for pulmonary arterial hypertension and interstitial lung disease in mixed connective tissue disease.

OBJECTIVE: The presence of anti-U1 RNP antibodies (Abs) is critical for diagnosing MCTD. The aim of this study is to evaluate the clinical relevance of anti-survival motor neuron (SMN) complex Abs, which often coexist with anti-U1 RNP Abs. METHODS: A total of 158 newly diagnosed consecutive cases of SLE, SSc or MCTD with anti-U1 RNP Abs were enrolled in this multicentre observational study between April 2014 and August 2022. Serum anti-SMN complex Abs were screened by immunoprecipitation of 35S-methionine-labelled cell extracts, and associations between anti-SMN complex Abs positivity and clinical characteristics were analysed. RESULTS: Anti-SMN complex Abs were detected in 36% of MCTD patients, which was significantly higher than that in SLE (8%) or SSc (12%). Among MCTD patients classified based on the combination of the clinical features of SLE, SSc and idiopathic inflammatory myopathies, anti-SMN complex Abs showed the highest prevalence in a subset with clinical features of all three components. Anti-SMN complex Abs-positive MCTD had a higher prevalence of pulmonary arterial hypertension (PAH) and interstitial lung disease (ILD), which are related to poor prognosis, than negative patients. Moreover, all three cases of death within 1 year of the treatment were positive for anti-SMN complex Abs. CONCLUSIONS: Anti-SMN complex Abs is the first biomarker of a typical subset of MCTD which bears organ damages such as PAH and ILD.

Treatment strategies and survival of patients with connective tissue disease and pulmonary arterial hypertension: a COMPERA analysis.

OBJECTIVES: Pulmonary arterial hypertension (PAH) occurs in various connective tissue diseases (CTDs). We sought to assess contemporary treatment patterns and survival of patients with various forms of CTD-PAH. METHODS: We analysed data from COMPERA, a European pulmonary hypertension registry, to describe treatment strategies and survival in patients with newly diagnosed PAH associated with SSc, SLE, MCTD, UCTD and other types of CTD. All-cause mortality was analysed according to the underlying CTD. For patients with SSc-PAH, we also assessed survival according to initial therapy with endothelin receptor antagonists (ERAs), phosphodiesterase type 5 inhibitors (PDE5is) or a combination of these two drug classes. RESULTS: This analysis included 607 patients with CTD-PAH. Survival estimates at 1, 3 and 5 years for SSc-PAH (n = 390) were 85%, 59% and 42%; for SLE-PAH (n = 34) they were 97%, 77% and 61%; for MCTD-PAH (n = 33) they were 97%, 70% and 59%; for UCTD-PAH (n = 60) they were 88%, 67% and 52%; and for other CTD-PAH (n = 90) they were 92%, 69% and 55%, respectively. After multivariable adjustment, the survival of patients with SSc-PAH was significantly worse compared with the other conditions (P = 0.001). In these patients, the survival estimates were significantly better with initial ERA-PDE5i combination therapy than with initial ERA or PDE5i monotherapy (P = 0.016 and P = 0.012, respectively). CONCLUSIONS: Mortality remains high in patients with CTD-PAH, especially for patients with SSc-PAH. However, for patients with SSc-PAH, our results suggest that long-term survival may be improved with initial ERA-PDE5i combination therapy compared with initial monotherapy.

Mixed Connective Tissue Disease Presenting With Psychosis-A Case Report.

ABSTRACT: Mixed connective tissue disease (MCTD) is a systemic autoimmune disease with features overlapping multiple autoimmune disorders. One study found that over 55% of patients with MCTD experienced neuropsychiatric symptoms, the most common of which was an "aseptic meningitis-like syndrome." We present a case of a 17-year-old adolescent girl presenting with abnormal speech and behavior, auditory hallucinations, and paranoid delusions after an isolated episode of fever. She was treated for her psychotic symptoms but later developed symptoms resembling neuroleptic malignant syndrome. An antibody screen revealed elevated anti-U1-ribonucleoprotein antibodies with a possible diagnosis of MCTD. She finally responded to steroid therapy. To our knowledge, this is the first reported case of MCTD initially presenting with psychosis. A diagnosis of autoimmune disorders should be kept in the differential of similar clinical presentations including connective tissue disorders and autoimmune thyroid conditions.

Mixed connective tissue disease-myositis overlap syndrome presenting as an allergic disease process to the emergency department: A case report.

BACKGROUND: The "allergy epidemic" of the Western World, has led to an overwhelming number of emergency department presentations with allergic rhinitis, allergic conjunctivitis, atopic eczema, and asthma. Careful consideration should be given to screening for the typical signs and symptoms of Mixed connective tissue disease (MCTD) in patients presenting to the ED with what appears to be a simple allergic process. MCTD is a rare systemic rheumatic disease characterized by high levels of anti-U1RNP antibodies and various clinical signs and symptoms. The pathophysiology of MCTD is poorly understood. An association between allergen-mediated processes and MCTD has been reported in recent literature. Our case report involves a 40 year old African American female with initial outpatient presentation suggestive of atopic disease, with progressive worsening of symptoms while receiving allergen immunotherapy. The patient presented to the emergency department with bilateral leg cramping. The patient was found to have a CPK of 7000 unresponsive to fluids. The patient was evaluated by the Allergy and Rheumatology services. The patient was ultimately diagnosed with MCTD-Myositis Overlap Syndrome and started on steroids and IVIG with improvement in symptoms. While MCTD is not a diagnosis readily made in the ED, early identification and treatment of the disease is critical for prevention of long term complications.

Fractional exhaled nitric oxide in idiopathic pulmonary arterial hypertension and mixed connective tissue disease complicating pulmonary hypertension.

BACKGROUND: Fractional exhaled nitric oxide (FeNO) has been extensively studied in various causes of pulmonary hypertension (PH), but its utility as a noninvasive marker remains highly debated. The objective of our study was to assess FeNO levels in patients with idiopathic pulmonary arterial hypertension (IPAH) and mixed connective tissue disease complicating pulmonary hypertension (MCTD-PH), and to correlate them with respiratory functional data, disease severity, and cardiopulmonary function. METHODS: We collected data from 54 patients diagnosed with IPAH and 78 patients diagnosed with MCTD-PH at the Shanghai Pulmonary Hospital Affiliated to Tongji University. Our data collection included measurements of brain natriuretic peptide (pro-BNP), cardiopulmonary exercise test (CPET), pulmonary function test (PFT), impulse oscillometry (IOS), and FeNO levels. Additionally, we assessed World Health Organization functional class (WHO-FC) of each patient. RESULTS: (1) The fractional exhaled concentration of nitric oxide was notably higher in patients with IPAH compared to those with MCTD-PH. Furthermore, within the IPAH group, FeNO levels were found to be lower in cases of severe IPAH compared to mild IPAH (P = 0.024); (2) In severe pulmonary hypertension as per the WHO-FC classification, FeNO levels in IPAH exhibited negative correlations with FEV1/FVC (Forced Expiratory Velocity at one second /Forced Vital Capacity), MEF50% (Maximum Expiratory Flow at 50%), MEF25%, and MMEF75/25% (Maximum Mid-expiratory Flow between 75% and 25%), while in severe MCTD-PH, FeNO levels were negatively correlated with R20% (Resistance at 20 Hz); (3) ROC (Receiving operator characteristic curve) analysis indicated that the optimal cutoff value of FeNO for diagnosing severe IPAH was 23ppb; (4) While FeNO levels tend to be negatively correlated with peakPETO2(peak end-tidal partial pressure for oxygen) in severe IPAH, in mild IPAH they had a positive correlation to peakO2/Heart rate (HR). An interesting find was observed in cases of severe MCTD-PH, where FeNO levels were negatively correlated with HR and respiratory exchange ratio (RER), while positively correlated with O2/HR throughout the cardiopulmonary exercise test. CONCLUSION: FeNO levels serve as a non-invasive measure of IPAH severity. Although FeNO levels may not assess the severity of MCTD-PH, their significant makes them a valuable tool when assessing severe MCTD-PH.

[Mixed connective tissue disease and its management]. / La connectivite mixte et sa prise en charge.

Mixed connective tissue disease (MCTD) is a rare autoimmune condition. Since its first description 50 years ago, its mere existence has been debated, given that it shares features of other autoimmune diseases, such as systemic lupus erythematosus (SLE), systemic sclerosis, inflammatory myopathy, rheumatoid arthritis and Sjogren's syndrome. Also, while antibodies to U1-RNP are essential for the diagnosis of MCTD, these antibodies may be expressed in other circumstances, such as in case of SLE. Nevertheless, the patient fulfilling criteria for MCTD needs specific management. In this review, we describe the clinical features and the potential complications of this complex disease, often wrongly disregarded as benign. We will also emphasize the recommended follow-up exams and address treatment, which is currently lacking formal recommendations.

La connectivite mixte (mixed connective tissue disease (MCTD)) est une maladie auto-immune rare. Dès sa description il y a cinquante ans, l'existence propre de la MCTD est débattue, car les limites avec d'autres maladies, comme le lupus érythémateux systémique (LES), la sclérodermie, les myopathies inflammatoires, la polyarthrite rhumatoïde et le syndrome de Sjögren, sont floues. Les anticorps anti-U1-RNP obligatoires au diagnostic de MCTD sont également exprimés dans d'autres circonstances, comme le LES. Quoi qu'il en soit, le patient présentant des critères de MCTD nécessite une prise en charge spécifique. Nous présentons ici les signes cliniques et complications potentielles d'une maladie longtemps estimée à tort comme d'évolution bénigne. Nous abordons aussi les examens de suivi recommandés et la thérapeutique, qui reste à ce jour mal définie.

Population-based prevalence and incidence estimates of mixed connective tissue disease from the Manhattan Lupus Surveillance Program.

OBJECTIVE: Epidemiological data for MCTD are limited. Leveraging data from the Manhattan Lupus Surveillance Program (MLSP), a racially/ethnically diverse population-based registry of cases with SLE and related diseases including MCTD, we provide estimates of the prevalence and incidence of MCTD. METHODS: MLSP cases were identified from rheumatologists, hospitals and population databases using a variety of International Classification of Diseases, Ninth Revision codes. MCTD was defined as one of the following: fulfilment of our modified Alarcon-Segovia and Kahn criteria, which required a positive RNP antibody and the presence of synovitis, myositis and RP; a diagnosis of MCTD and no other diagnosis of another CTD; and a diagnosis of MCTD regardless of another CTD diagnosis. RESULTS: Overall, 258 (7.7%) cases met a definition of MCTD. Using our modified Alarcon-Segovia and Kahn criteria for MCTD, the age-adjusted prevalence was 1.28 (95% CI 0.72, 2.09) per 100 000. Using our definition of a diagnosis of MCTD and no other diagnosis of another CTD yielded an age-adjusted prevalence and incidence of MCTD of 2.98 (95% CI 2.10, 4.11) per 100 000 and 0.39 (95% CI 0.22, 0.64) per 100 000, respectively. The age-adjusted prevalence and incidence were highest using a diagnosis of MCTD regardless of other CTD diagnoses and were 16.22 (95% CI 14.00, 18.43) per 100 000 and 1.90 (95% CI 1.49, 2.39) per 100 000, respectively. CONCLUSIONS: The MLSP provided estimates for the prevalence and incidence of MCTD in a diverse population. The variation in estimates using different case definitions is reflective of the challenge of defining MCTD in epidemiologic studies.

In-depth characterization of pulmonary arterial hypertension in mixed connective tissue disease: a French national multicentre study.

OBJECTIVE: Pulmonary arterial hypertension (PAH) is a leading cause of death in MCTD. We aimed to describe PAH in well-characterized MCTD patients. METHODS: MCTD patients enrolled in the French Pulmonary Hypertension Registry with a PAH diagnosis confirmed by right heart catheterization were included in the study and compared with matched controls: MCTD patients without PAH, SLE patients with PAH and SSc patients with PAH. Survival rates were estimated by the Kaplan-Meier method and risk factors for PAH in MCTD patients and risk factors for mortality in MCTD-PAH were sought using multivariate analyses. RESULTS: Thirty-six patients with MCTD-PAH were included in the study. Comparison with MCTD patients without PAH and multivariate analysis revealed that pericarditis, polyarthritis, thrombocytopenia, interstitial lung disease (ILD) and anti-Sm antibodies were independent predictive factors of PAH/PH in MCTD. Estimated survival rates at 1, 5 and 10 years following PAH diagnosis were 83%, 67% and 56%, respectively. MCTD-PAH presentation and survival did not differ from SLE-PAH and SSc-PAH. Multivariate analysis revealed that tobacco exposure was an independent factor predictive of mortality in MCTD-PAH. CONCLUSION: PAH is a rare and severe complication of MCTD associated with a 56% 10-year survival. We identified ILD, pericarditis, thrombocytopenia and anti-Sm antibodies as risk factors for PAH in MCTD and tobacco exposure as a predictor of mortality in MCTD-PAH.

Standardized nailfold capillaroscopy in children with rheumatic diseases: a worldwide study.

OBJECTIVES: To standardly assess and describe nailfold videocapillaroscopy (NVC) assessment in children and adolescents with juvenile rheumatic and musculoskeletal diseases (jRMD) vs healthy controls (HCs). MATERIAL AND METHODS: In consecutive jRMD children and matched HCs from 13 centres worldwide, 16 NVC images per patient were acquired locally and read centrally per international consensus standard evaluation of the EULAR Study Group on Microcirculation in Rheumatic Diseases. A total of 95 patients with JIA, 22 with JDM, 20 with childhood-onset SLE (cSLE), 13 with juvenile SSc (jSSc), 21 with localized scleroderma (lSc), 18 with MCTD and 20 with primary RP (PRP) were included. NVC differences between juvenile subgroups and HCs were calculated through multivariable regression analysis. RESULTS: A total of 6474 images were assessed from 413 subjects (mean age 12.1 years, 70.9% female). The quantitative NVC characteristics were significantly lower or higher in the following subgroups compared with HCs: for density: lower in jSSc, JDM, MCTD, cSLE and lSc; for dilations: higher in jSSc, MCTD and JDM; for abnormal shapes: higher in JDM and MCTD; for haemorrhages: higher in jSSc, MCTD, JDM and cSLE. The qualitative NVC assessment of JIA, lSc and PRP did not differ from HCs, whereas the cSLE and jSSc, MCTD, JDM and cSLE subgroups showed more non-specific and scleroderma patterns, respectively. CONCLUSIONS: This analysis resulted from a pioneering registry of NVC in jRMD. The NVC assessment in jRMD differed significantly from HCs. Future prospective follow-up will further elucidate the role of NVC in jRMD.

The prevalence of pulmonary arterial hypertension in patients with mixed connective tissue disease: a systematic review and meta-analysis.

OBJECTIVES: The prevalence and outcome of mixed connective tissue disease-associated pulmonary arterial hypertension (MCTD-PAH) has not been well understood. Our aim was to review the current knowledge on the prevalence, severity, and mortality of MCTD-PAH. We also aimed to examine the prevalence trend of MCTD-PAH over the years. METHODS: PubMed/Medline, Embase, Scopus and Web of Science electronic databases were searched for the published randomised controlled clinical trials (RCTs) and observational/original studies on PAH in patients with MCTD from January 1972 to December 2020. RESULTS: The results were pooled using random-effects meta-analysis based on DerSimonian and Laird method. A total of 983 patients from eight studies were included in the meta-analysis (K=8, n=983). Pooled prevalence of PAH in MCTD patients was 12.53% [95% CI 8.30-18.48%] with significant level statistical heterogeneity (tau2=0.30, tau=0.55, i2 83.3%, H=2.13 Q(df,7)=31.90, p=0.001). There was no association between PAH and female gender or age. The percentage of deaths in MCTD patients due to PAH varied and reached up to 81.8%. CONCLUSIONS: This is the first systematic review and meta-analysis investigating the prevalence of PAH in patients with MCTD and it revealed an overall prevalence of PAH in patients with MCTD of 12.53%. Our results showed trends of reduced prevalence of MCTD-PAH over last four decade, reconfirmed the lower prevalence rate in recent studies, but revealed an increased mortality rate. We also determined the low impact of the age, gender, and interstitial lung disease on MCTD-PAH.

The diagnostic challenge of patients with anti-U1-RNP antibodies.

Anti-U1-RNP antibodies are necessary for the diagnosis of mixed connective tissue disease (MCTD), but they are also prevalent in other connective tissue diseases, especially systemic lupus erythematosus (SLE), from which distinction remains challenging. We aimed to describe the presentation and outcome of patients with anti-U1-RNP antibodies and to identify factors to distinguish MCTD from SLE. We retrospectively applied the criteria sets for MCTD, SLE, systemic sclerosis (SSc) and rheumatoid arthritis (RA) to all patients displaying anti-U1-RNP antibodies in the hospital of Caen from 2000 to 2020. Thirty-six patients were included in the analysis. Eighteen patients (50%) satisfied at least one of the MCTD classifications, 11 of whom (61%) also met 2019 ACR/EULAR criteria for SLE. Twelve other patients only met SLE without MCTD criteria, and a total of 23 patients (64%) met SLE criteria. The most frequent manifestations included Raynaud's phenomenon (RP, 91%) and arthralgia (67%). We compared the characteristics of patients meeting only the MCTD (n = 7), SLE (n = 12), or both (n = 11) criteria. Patients meeting the MCTD criteria were more likely to display SSc features, including sclerodactyly (p < 0.01), swollen hands (p < 0.01), RP (p = 0.04) and esophageal reflux (p < 0.01). The presence of scleroderma features (swollen hands, sclerodactyly, gastro-oesophageal reflux), was significantly associated with the diagnosis of MCTD. Conversely, the absence of those manifestations suggested the diagnosis of another definite connective tissue disease, especially SLE.

Pediatric mixed connective tissue disease versus other overlap syndromes: a retrospective multicenter cohort study.

Pediatric mixed connective tissue disease (MCTD) is a subgroup of overlap syndromes. We aimed to compare the characteristics and outcomes in children with MCTD and other overlap syndromes. All MCTD patients met either Kasukawa or Alarcon-Segovia and Villareal criteria. The patients with other overlap syndromes had the features of ≥ 2 autoimmune rheumatic diseases but did not meet MCTD diagnostic criteria. Thirty MCTD (F/M = 28/2) and thirty (F/M = 29/1) overlap patients were included (disease onset < 18 years). The most prominent phenotype at disease onset and the last visit was systemic lupus erythematosus (SLE) in the MCTD group; juvenile idiopathic arthritis and dermatomyositis/polymyositis, respectively, in the overlap group. At the last visit, systemic sclerosis (SSc) phenotype was more frequent among MCTD than overlap patients (60% vs. 33.3%; p = 0.038). The frequency of the predominant SLE phenotype had decreased (60% to 36.7%), while predominant SSc phenotype had increased (13.3% to 33.3%) during follow-up in MCTD patients. Weight loss (36.7% vs. 13.3%), digital ulcers (20% vs. 0), swollen hands (60% vs. 20%), Raynaud phenomenon (86.7% vs. 46.7%), hematologic involvement (70% vs. 26.7%), and anti-Sm positivity (29% vs. 3.3%) were more common, while Gottron papules (16.7% vs. 40%) were less frequent among MCTD than overlap patients (p < 0.05). A higher percentage of overlap patients achieved complete remission than MCTD patients (51.7% vs. 24.1%; p = 0.047). The disease phenotype and outcome differ between pediatric MCTD and other overlap syndromes where MCTD may be regarded as a more severe disease. Analyzing these patients could pave the way for early and effective treatment.

Cardiac dysfunction in mixed connective tissue disease: a nationwide observational study.

We aimed to identify cardiac function in patients with established mixed connective tissue disease (MCTD). This was a cross-sectional case-control study of well-characterised MCTD patients who had previously been included in a nationwide cohort. Assessments comprised protocol transthoracic echocardiography, electrocardiogram and blood samples. In patients only, we evaluated the findings of high-resolution pulmonary computed tomography and disease activity. We assessed 77 MCTD patients (mean age 50.5 ± 12.3 years) with a mean disease duration of 16.4 years, and 59 age- and sex-matched healthy controls (49.9 ± 11.7 years). By echocardiography, measures of left ventricular function, i.e. fractional shortening (38.1 ± 6.4% vs. 42.3 ± 6.6%, p < 0.001), mitral annulus plane systolic excursion (MAPSE) (13.7 ± 2.1 mm vs. 15.3 ± 2.3 mm, p < 0.001) and early diastolic velocity of the mitral annulus (e') (0.09 ± 0.02 m/s vs. 0.11 ± 0.03 m/s, p = 0.002) were subclinical and lower in patients than controls. Right ventricular dysfunction was found in patients assessed by tricuspid annular plane systolic excursion (TAPSE) (22.7 ± 4.0 mm vs. 25.5 ± 4.0 mm, p < 0.001). While cardiac dysfunction was not associated with pulmonary disease, e' and TAPSE were found to correlate with disease activity at baseline. In this cohort of MCTD patients, echocardiographic examinations demonstrated a higher frequency of cardiac dysfunction than in matched controls. Cardiac dysfunction was associated with disease activity at baseline, but was independent of cardiovascular risk factors and pulmonary disease. Our study indicates that cardiac dysfunction is part of the multi-organ affliction seen in MCTD.

Myocarditis in connective tissue diseases: an often-overlooked clinical manifestation.

To discuss what is currently known about myocarditis in the context of major connective tissue diseases, including Systemic lupus erythematosus, Rheumatoid Arthritis, Sjogren, Dermato-myositis and Polymyositis, Systemic Sclerosis, and Mixed connective tissue disease. Variability exists between studies regarding the incidence of myocarditis in connective tissue diseases, which is hypothesized to be the result of its subclinical course in most cases. Extensive gaps of knowledge exist in the field of pathophysiology. Although endomyocardial biopsy remains to be the gold standard for diagnosis, the advancement in non-invasive modalities such as cardiac MRI, echocardiography, and nuclear medicine has allowed for earlier and more frequent detection of myocarditis. A lack of treatment guidelines was found across the different connective tissue diseases. Most of the literature available revolved around myocarditis in the context of Systemic lupus erythematosus. Numerous recent studies were published that contributed to advancements in diagnosis and treatment however, there remains a lack of diagnostic and treatment guidelines.

A systematic review of the incidence, management and prognosis of new-onset autoimmune connective tissue diseases after COVID-19.

A literature review on new-onset autoimmune connective tissue diseases (ACTDs) following COVID-19 is lacking. We evaluated potential associations between COVID-19 and the development of new-onset ACTDs. The "population" was adults with disease terms for ACTDs, including systemic lupus erythematosus (SLE), Sjogren's syndrome, systemic sclerosis (SSc), idiopathic inflammatory myositis (IIM), anti-synthetase syndrome, mixed CTD and undifferentiated CTD, and "intervention" as COVID-19 and related terms. Databases were searched for English-language articles published until September 2022. We identified 2236 articles with 28 ultimately included. Of the 28 included patients, 64.3% were female, with a mean age was 51.1 years. The USA reported the most cases (9/28). ACTD diagnoses comprised: 11 (39.3%) IIM (including four dermatomyositis); 7 (25%) SLE; four (14.3%) anti-synthetase syndrome; four (14.3%) SSc; two (7.1%) other ACTD (one lupus/MCTD overlap). Of eight, four (14.3%) patients (including that with lupus/MCTD) had lupus nephritis. The average time from COVID-19 to ACTD diagnosis was 23.7 days. A third of patients were admitted to critical care, one for treatment of haemophagocytic lymphohistiocytosis in SLE (14 sessions of plasmapheresis, rituximab and intravenous corticosteroids) and nine due to COVID-19. 80% of patients went into remission of ACTD following treatment, while three (10%) patients died-one due to macrophage activation syndrome with anti-synthetase syndrome and two from unreported causes. Our results suggest a potential association between COVID-19 and new-onset ACTDs, notably in young females, reflecting more comprehensive CTD epidemiology. The most common diagnosis in our cohort was IIM. The aetiology and mechanisms by which ACTDs emerge following COVID-19 remain unknown and require further research.

Association of red cell distribution width with pulmonary arterial hypertension in patients with mixed connective tissue disease.

BACKGROUND: Pulmonary arterial hypertension (PAH) is a severe complication of mixed connective tissue disease (MCTD) and contributes to increased morbidity and mortality. Still, the demographic characteristics and risk factors of PAH in MCTD remain poorly understood. This study explored risk factors for PAH development in MCTD. METHODS: Data from patients with MCTD and PAH hospitalized from May 2009 to December 2022 in a single center were collected and compared with patients with MCTD without PAH. The variables were analyzed by logistic regression to identify the factors associated with PAH in patients with MCTD. The receiver-operating characteristic (ROC) curve was used to assess the diagnostic value of the identified factors. RESULTS: Finally, 119 patients with MCTD were included; 46 had PAH. The mean age at PAH onset and diagnosis was 38.9 ± 13.4 and 39.9 ± 13.7 years, respectively. The median pulmonary arterial systolic pressure (PASP) was 67.0 mmHg. The median brain natriuretic peptide (BNP) level was 180.0 pg/ml at PAH diagnosis. Red cell distribution width (RDW) (OR: 2.128; 95% confidence interval: 1.497-3.026; P < 0.001) was associated with PAH in patients with MCTD. There was a positive correlation between RDW and PASP (r = 0.716, P < 0.001). At a cutoff of 15.2%, RDW had the best sensitivity (80.4%) and specificity (82.2%) for PAH. CONCLUSION: RDW may serve as a sensitive index to predict PAH in patients with MCTD.

Mixed Connective Tissue Disease as Different Entity: Global Methylation Aspect.

Mixed connective tissue disease (MCTD) is a very rare disorder that belongs in the rare and clinically multifactorial groups of diseases. The pathogenesis of MCTD is still unclear. The best understood epigenetic alteration is DNA methylation whose role is to regulate gene expression. In the literature, there are ever-increasing assumptions that DNA methylation can be one of the possible reasons for the development of Autoimmune Connective Tissue Diseases (ACTDs) such as systemic sclerosis (SSc) and systemic lupus erythematosus (SLE). The aim of this study was to define the global DNA methylation changes between MCTD and other ACTDs patients in whole blood samples. The study included 54 MCTD patients, 43 SSc patients, 45 SLE patients, and 43 healthy donors (HC). The global DNA methylation level was measured by ELISA. Although the global DNA methylation was not significantly different between MCTD and control, we observed that hypomethylation distinguishes the MCTD patients from the SSc and SLE patients. The present analysis revealed a statistically significant difference of global methylation between SLE and MCTD (p < 0.001), SLE and HC (p = 0.008), SSc and MCTD (p ≤ 0.001), and SSc and HC (p < 0.001), but neither between MCTD and HC (p = 0.09) nor SSc and SLE (p = 0.08). The highest % of global methylation (median, IQR) has been observed in the group of patients with SLE [0.73 (0.43, 1.22] and SSc [0,91 (0.59, 1.50)], whereas in the MCTD [0.29 (0.20, 0.54)], patients and healthy subjects [0.51 (0.24, 0.70)] were comparable. In addition, our study provided evidence of different levels of global DNA methylation between the SSc subtypes (p = 0.01). Our study showed that patients with limited SSc had a significantly higher global methylation level when compared to diffuse SSc. Our data has shown that the level of global DNA methylation may not be a good diagnostic marker to distinguish MCTD from other ACTDs. Our research provides the groundwork for a more detailed examination of the significance of global DNA methylation as a distinguishing factor in patients with MCTD compared to other ACTDs patients.

Doubtful Clinical Value of Subtyping Anti-U1-RNP Antibodies Regarding the RNP-70 kDa Antigen in Sera of Patients with Systemic Lupus Erythematosus.

The detection of antinuclear antibodies is central to the diagnosis and prognosis of systemic lupus erythematosus (SLE), primary Sjögren's syndrome (pSS) and mixed connective tissue disease (MCTD). Anti-U1-RNP and anti-RNP70 antibodies were assayed in the sera of patients with SLE (n = 114), pSS (n = 54) and MCTD (n = 12). In the SLE group, 34/114 (30%) were anti-U1-RNP positive, and 21/114 (18%) were both anti-RNP70 positive and anti-U1-RNP positive. In the MCTD group, 10/12 (83%) were anti-U1-RNP positive, and 9/12 (75%) were anti-RNP70 positive. Only one individual with pSS was antibody positive (for both anti-U1-RNP and anti-RNP70). All anti-RNP70-positive samples were also anti-U1-RNP positive. Anti-U1-RNP-positive subjects with SLE were younger (p < 0.0001); showed lower concentrations of complement protein 3 (p = 0.03); had lower eosinophil (p = 0.0005), lymphocyte (p = 0.006) and monocyte (p = 0.03) counts; and had accrued less organ damage (p = 0.006) than the anti-U1-RNP-negative SLE patients. However, we observed no significant clinical or laboratory parameter differences between the anti-U1-RNP-positive individuals with/without anti-RNP70 in the SLE group. In conclusion, anti-RNP70 antibodies are not exclusive to MCTD but are rarely detected in pSS and healthy individuals. In SLE, anti-U1-RNP antibodies are associated with a clinical phenotype that resembles MCTD, with hematologic involvement and less damage accrual. Based on our results, the clinical value of subtyping anti-RNP70 in anti-U1-RNP-positive sera appears to be of limited value.