An explainable machine learning-based model to predict intensive care unit admission among patients with community-acquired pneumonia and connective tissue disease.

BACKGROUND: There is no individualized prediction model for intensive care unit (ICU) admission on patients with community-acquired pneumonia (CAP) and connective tissue disease (CTD) so far. In this study, we aimed to establish a machine learning-based model for predicting the need for ICU admission among those patients. METHODS: This was a retrospective study on patients admitted into a University Hospital in China between November 2008 and November 2021. Patients were included if they were diagnosed with CAP and CTD during admission and hospitalization. Data related to demographics, CTD types, comorbidities, vital signs and laboratory results during the first 24 h of hospitalization were collected. The baseline variables were screened to identify potential predictors via three methods, including univariate analysis, least absolute shrinkage and selection operator (Lasso) regression and Boruta algorithm. Nine supervised machine learning algorithms were used to build prediction models. We evaluated the performances of differentiation, calibration, and clinical utility of all models to determine the optimal model. The Shapley Additive Explanations (SHAP) and Local Interpretable Model-Agnostic Explanations (LIME) techniques were performed to interpret the optimal model. RESULTS: The included patients were randomly divided into the training set (1070 patients) and the testing set (459 patients) at a ratio of 70:30. The intersection results of three feature selection approaches yielded 16 predictors. The eXtreme gradient boosting (XGBoost) model achieved the highest area under the receiver operating characteristic curve (AUC) (0.941) and accuracy (0.913) among various models. The calibration curve and decision curve analysis (DCA) both suggested that the XGBoost model outperformed other models. The SHAP summary plots illustrated the top 6 features with the greatest importance, including higher N-terminal pro-B-type natriuretic peptide (NT-proBNP) and C-reactive protein (CRP), lower level of CD4 + T cell, lymphocyte and serum sodium, and positive serum (1,3)-ß-D-glucan test (G test). CONCLUSION: We successfully developed, evaluated and explained a machine learning-based model for predicting ICU admission in patients with CAP and CTD. The XGBoost model could be clinical referenced after external validation and improvement.

Nail involvement in connective tissue diseases: an epidemiological, clinical, and dermoscopic study.

BACKGROUND: The assessment of nail changes in connective tissue diseases (CTD) has been rarely explored in previous studies. The use of dermoscopy to study vascular changes in nailfolds is an interesting diagnostic technique. The aim of the study was to describe the epidemiological, clinical, and dermoscopic features of nail lesions in CTD. METHODS: A prospective study was performed at the Dermatology Department of Habib Thameur Hospital (Tunis, Tunisia) in collaboration with the Internal Medicine Department over a period of 15 months, from July 2020 to September 2021, including patients diagnosed with systemic sclerosis (SS), systemic lupus erythematosus (SLE) and dermatomyositis (DM). RESULTS: Our study included 48 patients. Nail involvement was found in 44 cases. Dermoscopic nailfold abnormalities were identified in 37 cases. The most common clinical features were ragged cuticle, nailfold erythema, and onycholysis. Additionally, splinter hemorrhage, longitudinal ridging, lunula abnormalities, melanonychia, trachyonychia, leukonychia, increase in transverse curvature, parrot beak nail, half and half nails, and onychorrhexis were described. Nailfold dermoscopy showed a normal pattern in 10 cases, a nonspecific pattern in nine cases (SLE), and a scleroderma pattern in 29 cases (SS and DM). The scleroderma pattern was further categorized into an early pattern (6), an active pattern (14), and a late pattern (9). Normal pattern was observed solely in patients in remission. The late scleroderma pattern was associated with disease duration and systemic involvement. In SLE, disease activity correlated with onycholysis, nailfold erythema, and pathologic pattern in dermoscopy. However, patients with DM displayed a positive correlation between pulmonary involvement and scleroderma pattern. CONCLUSION: Nail involvement in CTD includes a diverse range of abnormalities. Despite being nonspecific, it can provide crucial clues for establishing a diagnosis. Nailfold dermoscopy serves as a mirror for microangiopathy, enabling the detection of changes at an initial stage, and thus, it becomes a diagnostic and prognostic tool.

Hereditary Connective Tissue Diseases and Risk of Post-Acute SARS-CoV-2.

We completed a retrospective review of data collected by the JH-CROWN consortium based on ICD10 codes for a hospitalized cohort. The severity and prevalence of COVID-19 and development of PASC within heritable connective tissue diseases were unknown; however, clinical observation suggested a thorough examination was necessary. We compared rates of disease severity, death, and PASC in connective tissue diseases versus the entire cohort as well as in diabetes and hypertension to determine if connective tissue disease was a risk factor. Of the 15,676 patients in the database, 63 (0.40%) had a connective tissue disease, which is elevated relative to the distribution in the population, suggesting a higher risk of severe disease. Within these 63 patients, 9.52% developed PASC compared to 2.54% in the entire cohort (p < 0.005). Elucidation of populations at high risk for severe disease and development of PASC is integral to improving treatment approaches. Further, no other study to date has examined the risk in those with connective tissue diseases and these data support a need for enhanced awareness among physicians, patients, and the community.

Longitudinal follow-up of mixed connective tissue disease and overlapping autoimmune diseases of childhood onset in the Afro-descendant population of the French West Indies.

INTRODUCTION: Overlap autoimmune syndromes (OAS) and mixed connective tissue disease (MCTD) are rare in children. We performed a retrospective, longitudinal and descriptive study of Afro-Caribbean patients from the French West Indies followed for MCTD and OAS to describe their characteristics and outcomes during childhood. METHODS: Retrospective study from January 2000 to 2023. Listings of patients were obtained from multiple sources: computerized hospital archives and national hospital-based surveillance system, registry of pediatricians and adult specialists in internal medicine and the national registry for rare diseases. MCTD was defined according to Kasukawa's criteria. OAS was defined as overlapping features of systemic lupus erythematosus (SLE), systemic sclerosis (SSc), and dermatomyositis/autoimmune myositis (DM/AM). RESULTS: Sixteen patients were included over a 23-year period (10 MCTD and 6 OAS). The incidence was 0.23 per 100,000 children-years. The mean age at diagnosis was 11.9 years old (2.4-17) with median follow up of 7.9 years (2.1-19.6). SLE phenotype was present in the highest, followed by SSc and DM/AM. Patients had an average of three flares during childhood (1-7). A quarter (25%) had symptomatic pulmonary arterial hypertension (PAH). Ninety-four percent received steroids during follow-up and 88% required a corticosteroid-sparing therapy. Three patients (19%) developed SLE after more than 10y of follow-up. There were no death and no chronic organ failure. CONCLUSION: This is the largest pediatric cohort of MCTD and OAS in Afro-descendant patients treated in a country with a high standard of care. The clinical evolution did not differ between MCTD and OAS. The main complication was PAH, more frequent in our cohort.

Fatigue and sleep quality in Chinese adults with connective tissue disease: A cross-sectional study.

OBJECTIVES: This study aims to evaluate fatigue and sleep quality among adults with connective tissue disease (CTD), and the interrelationship. METHODS: From April 2020 to February 2021, adult CTD patients hospitalized were invited to complete sociodemographic and disease-related data, Fatigue Severity Scale (FSS), and Pittsburgh Sleep Quality Index (PSQI), as well as laboratory detection through computer query. Statistical analysis was performed using SPSS 22.0. RESULTS: A total of 363 patients with CTD were included in the study. Of which, 313 patients were accompanied by single CTD (systemic lupus erythematosus (SLE) = 109, Sjogren's syndrome (SS) = 51, rheumatoid arthritis (RA) = 44, idiopathic inflammatory myopathies (IIM) = 36, Vasculitis = 17, systemic sclerosis (SSc) = 14, other = 42, respectively), and 50 patients had CTD ≥ 2. Compared with CTD = 1, patients with CTD ≥ 2 had longer disease duration, higher erythrocyte sedimentation rate, and higher IgG level (all P < 0.05). The prevalence of poor sleep quality in 363 CTD patients was 61.2%, among which, 59.1% for CTD = 1 and 74.0% for CTD ≥ 2, with significant difference (P = 0.045). Additionally, 75.5% experienced fatigue, and 75.4% for CTD = 1, 76.0% for CTD ≥ 2 (P = 0.927). Fatigue and sleep quality interacted in CTD patients (r = 0.236, P < 0.01; χ2 = 11.302, P = 0.001). Interestingly, no significant differences were found in the prevalence of fatigue and poor sleep quality among CTD subgroups, as well as the FSS score, the seven components of sleep quality and total PSQI score (P > 0.05). CONCLUSIONS: More than 3/5 CTD patients experience fatigue and poor sleep quality, and not different among CTD subgroups. Targeted interventions are needed to reduce fatigue, improve sleep quality, and ultimately improve the prognosis of patients with CTD.

Epidemiology of Sjögren syndrome.

Sjögren syndrome is a phenotypically varied autoimmune disorder that can occur alone in primary Sjögren syndrome or in association with other connective tissue diseases (CTDs), including rheumatoid arthritis, systemic lupus erythematosus (SLE) and systemic sclerosis (SSc). The estimation of the prevalence and incidence of Sjögren syndrome varies depending on diagnostic criteria and study design, making it difficult to estimate geographical and temporal trends. Nonetheless, disease phenotype is influenced by geographical origin, which is a risk factor for systemic activity. Whether mortality in primary Sjögren syndrome is increased compared with that of the general population is not yet known, but extra-glandular manifestations, in particular lymphomas, are clear risk factors for mortality. In CTDs associated with Sjögren syndrome, lymphoma risk seems higher than that of patients with CTD alone, and there is potentially lower disease activity in SLE with Sjögren syndrome and in SSc with Sjögren syndrome than in SLE or SSc alone.

Pulmonary arterial hypertension associated with connective tissue diseases (CTD-PAH): Recent and advanced data.

Pulmonary arterial hypertension (PAH), corresponding to group 1 of pulmonary hypertension classification, is a rare disease with a major prognostic impact on morbidity and mortality. PAH can be either primary in idiopathic and heritable forms or secondary to other conditions including connective tissue diseases (CTD-PAH). Within CTD-PAH, the leading cause of PAH is systemic sclerosis (SSc) in Western countries, whereas systemic lupus erythematosus (SLE) and mixed connective tissue disease (MCTD) are predominantly associated with PAH in Asia. Although many advances have been made during the last two decades regarding classification, definition early screening and risk stratification and therapeutic aspects with initial combination treatment, the specificities of CTD-PAH are not yet clear. In this manuscript, we review recent literature data regarding the updated definition and classification of PAH, pathogenesis, epidemiology, detection, prognosis and treatment of CTD-PAH.

[Analysis of pregnancy outcomes, disease progression, and risk factors in patients with undifferentiated connective tissue disease].

OBJECTIVE: To investigate the fetal and maternal outcomes, risk factors of disease progression and adverse pregnancy outcomes (APOs) in patients with undifferentiated connective tissue disease (UCTD). METHODS: This retrospective study described the outcomes of 106 pregnancies in patients with UCTD. The patients were divided into APOs group (n=53) and non-APOs group (n=53). The APOs were defined as miscarriage, premature birth, pre-eclampsia, premature rupture of membranes (PROM), intrauterine growth restriction (IUGR), postpartum hemorrhage (PPH), and stillbirth, small for gestational age infant (SGA), low birth weight infant (LBW) and birth defects. The differences in clinical manifestations, laboratory data and pregnancy outcomes between the two groups were compared. Logistic regression analysis was performed to analyze the risk factors for APOs and the progression of UCTD to definitive CTD. RESULTS: There were 99 (93.39%) live births, 4 (3.77%) stillbirths and 3 (2.83%) miscarriage, 20 (18.86%) preterm delivery, 6 (5.66%) SGA, 17 (16.03%) LBW, 11 (10.37%) pre-eclampsia, 7 (6.60%) cases IUGR, 19 (17.92%) cases PROM, 10 (9.43%) cases PPH. Compared with the patients without APOs, the patients with APOs had a higher positive rate of anti-SSA antibodies (73.58% vs. 54.71%, P=0.036), higher rate of leukopenia (15.09% vs. 3.77%, P=0.046), lower haemoglobin level [109.00 (99.50, 118.00) g/L vs. 124.00 (111.50, 132.00) g/L, P < 0.001].Multivariate Logistic regression analysis showed that leucopenia (OR=0.82, 95%CI: 0.688-0.994) was an independent risk factors for APOs in UCTD (P=0.042). Within a mean follow-up time of 5.00 (3.00, 7.00) years, the rate of disease progression to a definite CTD was 14.15%, including 8 (7.54%) Sjögren's syndrome, 4 (3.77%) systemic lupus erythematosus (SLE), 4 (3.77%) rheumatoid arthritis and 1 (0.94%) mixed connective tissue disease. Multivariate Cox proportional risk regression analysis showed that Raynaud phenomenon (HR=40.157, 95%CI: 3.172-508.326) was an independent risk factor for progression to SLE. CONCLUSION: Leukopenia is an independent risk factor for the development of APOs in patients with UCTD. Raynaud's phenmon is a risk factor for the progression of SLE. Tight disease monitoring and regular follow-up are the key measures to prevent adverse pregnancy outcomes and predict disease progression in UCTD patients with pregnancy.

Clinical effect of progressive pulmonary fibrosis on patients with connective tissue disease-associated interstitial lung disease: a single center retrospective cohort study.

The concept of progressive pulmonary fibrosis (PPF) has been introduced to predict the diverse prognosis of interstitial lung disease (ILD). However, the incidence and effect of PPF on outcomes in patients with connective tissue disease-associated interstitial lung disease (CTD-ILD) need to be elucidated. This study reviewed 197 patients with CTD-ILD. Symptomatic worsening, pulmonary function decline, and radiological deterioration were investigated to assess the fulfillment of PPF diagnostic criteria. Clinical outcomes, including mortality, were compared based on the presence or absence of PPF. The median follow-up duration was 17.4 months. The mean age of the patients was 64.0 years, and 60.9% were female. Among the underlying CTDs, rheumatoid arthritis (42.1%), inflammatory myositis (19.8%), and systemic sclerosis (13.2%) were the most common. Of the 197 patients, 37 (18.8%) met the diagnostic criteria for PPF during the follow-up period. Even after adjusting for other significant risk factors, PPF was independently associated with mortality [hazard ratio (HR) 3.856; 95% confidence interval (CI) 1.387-10.715; P = 0.010] and baseline albumin was marginally significantly associated with mortality (HR 0.549; CI 0.298-1.010; P = 0.054). The median survival was also significantly shorter in the PPF group than in the non-PPF group (72.3 ± 12.9 vs. 126.8 ± 15.5 months, P < 0.001). Baseline KL-6 ≥ 1000 (U/mL) was a significant risk factor for PPF (HR 2.885; CI 1.165-7.144; P = 0.022). In addition to increased mortality, the PPF group had significantly higher rates of respiratory-related hospitalizations, pneumonia, acute exacerbations, and weight loss than the non-PPF group. PPF is a significant prognostic indicator in patients with CTD-ILD. Thus, healthcare professionals should know that patients with CTD-ILD are at risk of PPF.

Clinical features and outcomes of children's interstitial lung disease accompanied with connective tissue disease: A prospective cohort study.

BACKGROUND: Medical complexity of childhood interstitial lung disease (chILD) with connective tissue disease (CTD) poses a considerable challenge to pediatricians. METHODS: Clinical characteristics, laboratory findings, pulmonary function tests (PFTs), treatments and outcomes obtained for patients with CTD-chILD were analyzed in a prospective study. RESULTS: Patients' median age at diagnosis was 7 years old. About 29.4% (15/51) suffered rapidly progressive childhood ILD (RP-chILD) with a high mortality rate (33.3%, 5/15), and the incidence of RP-chILD in juvenile idiopathic inflammatory myopathies was as high as 41.6% and the mortality rate was 30% (3/10). More than 70% patients had decreased diffusion capacity. The mean interval from symptoms-onset to diagnosis was 11.3 months. Compared to chILD with known CTD, the chILD proceeded CTD had a longer diagnosis interval, higher mortality, hospital stays and costs (P < 0.05). Lung imaging (33.3%) and lung function (72.7%) were partially reversible. The average survival time was 68.6 months. Cox univariate analysis showed that HRCT score ≥3, experiencing RP-chILD, cyanosis, acute respiratory distress syndrome (ARDS) and CD4 T cell <200 were significant predictors of death for chILD, whereas Cox multivariate analysis showed that ARDS was significant predictor of death for CTD-chILD, while IVIG support combined with corticosteroids and immunosuppressants was a protective factor. CONCLUSIONS: Care providers should conduct an assessment for CTD in chILD as a longer interval between the diagnosis of chILD and the CTD is associated with increased mortality. Complications as ARDS predict poor outcome in CTD-chILD, while IVIG support combined with corticosteroids and immunosuppressants is a protective factor.

Unclassifiable interstitial lung disease and autoimmunity: Towards IPAF in children?

INTRODUCTION: Interstitial pneumonia with autoimmune features (IPAF) has been defined for adults with interstitial lung disease (ILD) and autoimmunity who do not meet the criteria for a specific connective tissue disease (CTD). We aimed to determine whether IPAF criteria could apply to children. METHODS: We retrospectively studied patients with ILD and autoimmunity followed at Necker Hospital between 2008 and 2019. Children were classified according to specific CTD and IPAF criteria. The epidemiology and course of the disease were studied according to the final diagnosis. RESULTS: Among 27 patients, 6 fulfilled the criteria for IPAF and represented 4.5% of all patients with ILD during the study period. Other diagnoses included juvenile dermatomyositis (30%), overlap syndromes (19%), systemic lupus erythematosus (15%), systemic sclerosis (7%), mixed CTD (4%), and rheumatoid arthritis (4%). IPAF patients were more frequently boys versus CTD-ILD patients (67% vs. 14%, p = .02). Two patients had severe respiratory distress that led to death for one of them. The course was favorable for the others, with a good response to steroids. The course tended to be more favorable for IPAF patients than for those with CTD-ILD (0% lung fibrosis in the IPAF group vs. 43% in the CTD-ILD group, p = .07). CONCLUSION: We confirmed the existence of IPAF in children. Its prevalence was lower than in adults but comparable to that found for other pediatric series. Boys were more highly represented than in CTD-ILD. The course was favorable for most cases. Larger and more prospective studies are needed to confirm these results.

Clinical significance of interleukin-6, total bilirubin, CD3 + CD4 + T cells counts in the acute exacerbation of connective tissue disease-associated interstitial lung disease: a cross-sectional study.

OBJECTIVE: Interstitial lung disease (ILD) is a severe complication of connective tissue disease (CTD) that can significantly impact patients' prognosis and quality of life. However, the current diagnostic arena lacks reliable biomarkers for detecting and monitoring the progression and exacerbation of CTD-ILD. This study aimed to investigate the clinical value of 12 serum cytokines in the diagnosis of CTD-ILD and prediction of the risk of acute exacerbation (AE) in this disease. METHODS: This study was a cross-sectional investigation. Ninety-one hospitalized CTD patients were allocated into two groups: CTD-ILD group (n = 61) and CTD-non-ILD group (n = 30), and 30 sex-age matched healthy volunteers were enrolled as controls. The serum concentrations of interferon (IFN)-α, IFN-γ, tumor necrosis factor (TNF)-α, interleukin (IL)-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12p70, IL-17A, and IL-1ß were measured by Luminex suspension arrays. Logistic regression was employed to determine the significance of variables in the occurrence of AE-CTD-ILD. A nomogram was constructed to visualize the independent variables. RESULTS: Elevated levels of IL-6, IL-8, and TNF-α were observed and compared in the CTD-ILD group with CTD-non-ILD (all P < 0.05). Similarly, the levels of IL-6, IL-8 and TNF-α were higher in the acute exacerbation (AE-CTD-ILD) group compared with stable CTD-ILD (S-CTD-ILD) (P < 0.001, P < 0.001, and P = 0.022). Significant correlations between serum IL-6 and PaO2/FiO2 ratio (r = - 0.463, P < 0.001), percent predicted forced vital capacity (FVC%; r = - 0.362, P < 0.05), and total ground-glass opacity (GGO) score (r = 0.439, P < 0.001) were observed in CTD-ILD patients. Multivariate logistic regression analysis revealed that elevated IL-6 levels, total bilirubin (TBil), and decreased CD3 + CD4 + T cells counts were independent risk factors for the occurrence of AE-CTD-ILD (OR = 1.121, P = 0.024; OR = 1.865, P = 0.047; OR = 0.983, P = 0.037, respectively). Furthermore, by employing these three variables in combination for the prediction of AE status, their collective impact surpasses the independent effects of any single biomarker. CONCLUSIONS: Elevated levels of serum IL-6, IL-8, and TNF-α were associated with the complication of ILD in CTD patients and the occurrence of AE in CTD-ILD patients. IL-6 could be a promising serum biomarker of severity and the occurrence of AE in CTD-ILD patients. The combination of the three variables (IL-6 level, TBil and CD3 + CD4 + T cells) predicted the AE-CTD-ILD better.

KL-6 levels in the connective tissue disease population: typical values and potential confounders-a retrospective, real-world study.

Background: Krebs von den Lungen 6 (KL-6) is a potential biomarker for determining the severity of interstitial lung disease (ILD) in patients with connective tissue disease (CTD). Whether KL-6 levels can be affected by potential confounders such as underlying CTD patterns, patient-associated demographics, and comorbidities needs further investigation. Methods: From the database created by Xiangya Hospital, 524 patients with CTD, with or without ILD, were recruited for this retrospective analysis. Recorded data included demographic information, comorbidities, inflammatory biomarkers, autoimmune antibodies, and the KL-6 level at admission. Results of CT and pulmonary function tests were collected one week before or after KL-6 measurements. The percent of predicted diffusing capacity of the lung for carbon monoxide (DLCO%) and computed tomography (CT) scans were used to determine the severity of ILD. Results: Univariate linear regression analysis showed that BMI, lung cancer, TB, lung infections, underlying CTD type, white blood cell (WBC) counts, neutrophil (Neu) counts, and hemoglobin (Hb) were related to KL-6 levels. Multiple linear regression confirmed that Hb and lung infections could affect KL-6 levels independently; the ß were 9.64 and 315.93, and the P values were 0.015 and 0.039, respectively. CTD-ILD patients had higher levels of KL-6 (864.9 vs 463.9, P < 0.001) than those without ILD. KL-6 levels were closely correlated to the severity of ILD assessed both by CT and DLCO%. Additionally, we found that KL-6 level was an independent predictive factor for the presence of ILD and further constructed a decision tree model to rapidly determine the risk of developing ILD among CTD patients. Conclusion: KL-6 is a potential biomarker for gauging the incidence and severity of ILD in CTD patients. To use this typical value of KL-6, however, doctors should take Hb and the presence of lung infections into account.

[Interstitial pneumonia with autoimmune features: monocentric prospective study].

AIM: To study demographic, clinical, serological and morphological features of interstitial pneumonia with autoimmune features (IPAF), compare survival in IPAF and interstitial lung disease in connective tissue diseases (CTD-ILD), and identify predictors of mortality and transformation to CTD in the IPAF group. MATERIALS AND METHODS: The IPAF group included 48 patients (75.0% women, median age 57.5 years), CTD-ILD - 49 patients (79.6% women, median age 60.0 years). The analysis of demographic, clinical, laboratory and instrumental data was performed, as well as comparison of survival with the Kaplan-Meier method and the log-rank test in the IPAF and CTD-ILD groups. In the IPAF group, predictors of mortality and the development of CTD were studied with multivariate regression analysis. RESULTS: Duration of observation period did not differ significantly in the IPAF and CTD-ILD groups (40.0 and 37.0 months, respectively). Clinical criteria of IPAF were observed in 25 (52.1%) patients, serological - in 44 (91.7%), morphological - in 44 (91.7%). Mortality in the IPAF group was significantly higher than in the CTD-ILD group (29.2 and 6.1%, respectively; p=0.023). The presence of diabetes mellitus, CT-pattern of usual interstitial pneumonia, and an initial low forced vital capacity value were independent predictors of mortality in the IPAF group. During the observation period, the development of CTD was noted in 4 (8.3%) patients with IPAF. The independent predictor of the CTD development was the increased C-reactive protein level. CONCLUSION: IPAF is characterized by a lower survival rate compared to CTD-ILD, and a relatively low risk of CTD transformation.

Risk of autoimmune skin and connective tissue disorders after mRNA-based COVID-19 vaccination.

BACKGROUND: Data on the association between the development of autoimmune diseases and COVID-19 vaccination are limited. OBJECTIVE: To investigate the incidence and risk of autoimmune connective tissue disorders following mRNA-based COVID-19 vaccination. METHODS: This nationwide population-based study was conducted in South Korea. Individuals who received vaccination between September 8, 2020-December 31, 2021, were identified. Historical prepandemic controls were matched for age and sex in 1:1 ratio. The incidence rate and risk of disease outcomes were compared. RESULTS: A total of 3,838,120 vaccinated individuals and 3,834,804 controls without evidence of COVID-19 were included. The risk of alopecia areata, alopecia totalis, primary cicatricial alopecia, psoriasis, vitiligo, anti-neutrophil cytoplasmic antibody-associated vasculitis, sarcoidosis, Behcet disease, Crohn disease, ulcerative colitis, rheumatoid arthritis, systemic lupus erythematosus, systemic sclerosis, Sjogren syndrome, ankylosing spondylitis, dermato/polymyositis, and bullous pemphigoid was not significantly higher in vaccinated individuals than in controls. The risk was comparable according to age, sex, type of mRNA-based vaccine, and cross-vaccination status. LIMITATIONS: Possible selection bias and residual confounders. CONCLUSION: These findings suggest that most autoimmune connective tissue disorders are not associated with a significant increase in risk. However, caution is necessary when interpreting results for rare outcomes due to limited statistical power.

Lung Transplantation: A Viable Option for Connective Tissue Disease?

Interstitial lung disease (ILD) and pulmonary hypertension (PH) caused by connective tissue disease (CTD) are one of the main causes of morbidity and death in patients. Although the International Society for Heart & Lung Transplant suggested that ILD and PH related to CTD are rare indications for lung transplantation in 2006, many lung transplantation centers are concerned that the multisystem involvement of CTD will affect survival outcomes after lung transplantation, and CTD is regarded as a relative contraindication for lung transplantation. However, long-term and short-term survival after lung transplantation in CTD patients is similar compared with survival in common indications for lung transplantation such as idiopathic pulmonary fibrosis (IPF), and no higher incidence of complications after transplantation in many lung transplant centers. This suggests that lung transplantation may be beneficial in CTD patients with disease that progresses to end-stage lung disease, and CTD should not be considered a contraindication for lung transplantation. In the future, more prospective studies are needed to analyze the risk factors of lung transplantation in CTD patients to improve survival rates and reduce the risk of complications. This narrative review summarizes the selection and evaluation of candidates for CTD before lung transplantation and describes the clinical outcomes in CTD after lung transplantation in large-capacity lung transplantation center. The purpose of this review is to help rheumatologists decide when to refer patients with CTD-related lung involvement to a lung transplantation center and the conditions to consider before transplantation and to provide confidence to lung transplant experts.

Comparison of the diagnostic criteria for progressive pulmonary fibrosis in connective tissue disease related interstitial lung disease.

BACKGROUND: Progressive pulmonary fibrosis (PPF) is possible among patients with connective tissue disease (CTD) related interstitial lung disease (ILD). Our aim herein was to compare the prevalence and clinical characteristics of patients with CTD-ILD, with and without PPF, according to the different diagnostic criteria currently used in practice. METHODS: This retrospective study included patients diagnosed with CTD-ILD, with a ≥1-year follow-up of their lung function, at a single tertiary hospital in South Korea. Diagnostic criteria from two clinical trials (RELIEF and TRAIL1) and from a recently updated guideline (ATS/ERS/JRS/ALAT) were applied. RESULTS: Of the 107 patients included, 80% tested positive for Sjogren's disease, rheumatoid arthritis, and systemic sclerosis. The prevalence of CTD-ILD with PPF for the different diagnostic criteria was as follows: RELIEF, 25.2%; TRAIL1, 20.6%; and ATS/ERS/JRS/ALAT, 38.3%. More previous history of pulmonary tuberculosis and less positivity for antinuclear antibodies were identified in the PPF group. The radiologic pattern of ILD did not differ between patients with and without PPF, with a usual interstitial pneumonia pattern identified in 34.6% of the patients. Systemic steroids and immunomodulatory agents were used in about 80% of patients with PPF and 50% without PPF, irrespective of the diagnostic criteria used. Antifibrotic therapy was used in a limited number of patients in both groups. CONCLUSIONS: The proportion of patients with CTD-ILD and PPF was higher for the ATS/ERS/JRS/ALAT guideline criteria, without a between-group difference in clinical characteristics.

Pneumoconiosis combined with connective tissue disease in China: a cross-sectional study.

OBJECTIVE: To describe the prevalence, clinical features and potential risk factors of pneumoconiosis in combination with connective tissue disease (CTD) or positive autoantibodies. DESIGN: Cross-sectional study. SETTING: A retrospective study of adults recruited in China between December 2016 and November 2021. PARTICIPANTS: A total of 931 patients with pneumoconiosis at Beijing Chao-Yang Hospital were enrolled in this study; of these, 580 patients were included in the final analysis. MAIN OUTCOME MEASURES: Pneumoconiosis combined with CTD or positive autoantibodies was a major adverse outcome. RESULTS: In total, 13.8% (80/580) of the patients had combined pneumoconiosis with CTD, among whom the prevalence of CTD was 18.3% (46/251) in asbestosis and 11.4% (34/298) in silicosis/coal mine workers' pneumoconiosis. In comparison to the general Chinese adult population, the relative risk of various CTD in pneumoconiosis, including rheumatoid arthritis, systemic lupus erythematosus, systemic sclerosis, primary Sjögren's syndrome, idiopathic inflammatory myopathy and antineutrophil cytoplasmic antibodies-associated vasculitis, were 11.85, 12.12, 127.40, 4.23, 9.94 and 644.66, respectively. Multivariate analysis revealed that female sex (OR 2.55, 95% CI 1.56 to 4.17) and a later stage of pneumoconiosis (OR 2.04, 95% CI 1.24 to 3.34) were the independent risk factors for CTD in patients with pneumoconiosis (all p<0.050). CONCLUSION: CTD is highly prevalent in patients with pneumoconiosis, especially in patients of asbestosis, and silicosis/coal mine workers' pneumoconiosis. Female sex and later stages of pneumoconiosis are associated with an increased risk of combined with CTD.

Prevalence, imaging patterns and risk factors of interstitial lung disease in connective tissue disease: a systematic review and meta-analysis.

INTRODUCTION: Interstitial lung disease (ILD) is a frequent manifestation of connective tissue disease (CTD) with substantial variability in prevalence and outcomes reported across CTD subtypes. This systematic review summarises the prevalence, risk factors and ILD patterns on chest computed tomography of CTD-ILD. METHODS: A comprehensive search was performed in Medline and Embase to identify eligible studies. Meta-analyses were completed using a random effects model to determine the pooled prevalence of CTD-ILD and ILD patterns. RESULTS: 11 582 unique citations were identified with 237 articles included. Pooled prevalence of ILD was 11% in rheumatoid arthritis (95% CI 7-15%), 47% in systemic sclerosis (44-50%), 41% in idiopathic inflammatory myositis (33-50%), 17% in primary Sjögren's syndrome (12-21%), 56% in mixed connective tissue disease (39-72%) and 6% in systemic lupus erythematosus (3-10%). Usual interstitial pneumonia was the most prevalent ILD pattern in rheumatoid arthritis (pooled prevalence of 46%), while nonspecific interstitial pneumonia was the most common ILD pattern in all other CTD subtypes (pooled prevalence range 27-76%). Across all CTDs with available data, positive serology and higher inflammatory markers were risk factors for development of ILD. DISCUSSION: We identified substantial variability in ILD across CTD subtypes suggesting that CTD-ILD is too heterogenous to be considered a single entity.