Distinct phenotypes in mixed connective tissue disease: subgroups and survival

Targeting endothelial cells: A novel strategy for pulmonary fibrosis treatment

Endothelial cells (ECs) are a monolayer of flat cells lining the inner surfaces of blood and lymphatic vessels. They play a key role in many physiological and pathological processes. Specifically, they maintain vascular permeability and structural stability and participate in immune responses, inflammation, coagulation, and other vital functions. ECs play a decisive role in various age-related diseases; however, their involvement in pulmonary fibrosis (PF) remains poorly understood. PF refers to a group of chronic interstitial lung diseases characterised by progressive scarring of the pulmonary parenchyma, primarily caused by aberrant tissue repair mechanisms. These changes lead to irreversible loss of lung function. Although the exact pathophysiological mechanism underlying PF has not yet been elucidated, recent studies have indicated that ECs may play a pivotal role in PF. This review outlines the involvement of pulmonary vascular ECs in PF, focusing on the regulation of vascular remodelling and endothelial barrier integrity and on the maintenance of angiogenesis through EC-specific markers, such as vascular endothelial growth factor. This review also explores processes such as endothelial-to-mesenchymal transition, immune cell interactions, anti-EC antibody reactions, metabolic dysregulation, and cellular senescence. By elucidating recent advancements in understanding the role of ECs in PF and examining drugs targeting ECs for the treatment of PF, this study provides novel insights into the pathological mechanisms of PF and the development of endothelium-based therapeutic agents.

Risk Factors for Adverse Outcomes in Connective Tissue Disease-Associated Pulmonary Hypertension

Pulmonary hypertension (PH) is a rare, life-threatening condition that can be associated with connective tissue disease (CTD). The incidence and prevalence of PH in CTD varies by disease, whereby certain disease manifestations are particularly associated with PH; nonetheless, once present, PH is almost uniformly a major driver of adverse outcomes. In this paper, the authors review the published literature on major CTDs, including systemic sclerosis and systemic lupus erythematosus, and summarize the risk factors for developing PH in each disease and risk factors for adverse outcomes and mortality among patients with CTD-PH. This review highlights the need for early diagnosis of PH in CTD and the impact of PH overlap syndromes on patient outcomes, providing the practicing clinician with a practical summary of CTD-PH.

Pulmonary Hypertension Associated with Connective Tissue Disease

Pulmonary hypertension (PH), a syndrome characterized by elevated pulmonary pressures, commonly complicates connective tissue disease (CTD) and is associated with increased morbidity and mortality. The incidence of PH varies widely between CTDs; patients with systemic sclerosis are most likely to develop PH. Several different types of PH can present in CTD, including PH related to left heart disease and respiratory disease. Importantly, CTD patients are at risk for developing pulmonary arterial hypertension, a rare form of PH that is associated with high morbidity and mortality. Future therapies targeting pulmonary vascular remodeling may improve outcomes for patients with this devastating disease.

Predictors of myositis in mixed connective tissue disease: A multicentre retrospective study

OBJECTIVES

We aimed to identify clinical and serological predictors of myositis in mixed connective tissue disease (MCTD).

METHODS

We performed a nationwide, retrospective, multicentre study including adult-onset MCTD patients fulfilling at least one of the following diagnostic criteria: Sharp's, Kasukawa, Alarcón-Segovia, or Kahn's. Univariate analysis was performed using Chi-square, Fisher exact, Student's t or Mann-Whitney U tests, as appropriate. Multivariate analysis was performed using binary logistic regression.

RESULTS

Ninety-eight patients were included. Myositis was observed in 43.9% of patients, of whom 60.5% had myositis at disease onset. Proximal muscle weakness was described in 30 patients with muscle involvement (70%). Gastrointestinal involvement was identified in 28% and respiratory involvement in 29% of myositis patients. In the same subgroup of patients, 41.7% had a myopathic pattern on electromyography, and 47.1% had histological myositis features in the muscle biopsy. Fever (OR=6.96, p=0.022) was an independent predictor of myositis, regardless of sex, age at diagnosis, ancestry, and respiratory involvement. African ancestry (OR=8.39, p=0.019), leukopenia at the disease onset (OR 6.24, p=0.021), and younger age at diagnosis (OR=1.07/year, p=0.035) were identified as independent predictors of myositis at disease onset, regardless of sex and scleroderma pattern in capillaroscopy.

CONCLUSIONS

Myositis is a common manifestation of MCTD, even at the disease onset. African ancestry, leukopenia at the disease onset, younger age at diagnosis, and fever should prompt a thorough evaluation for myositis.

Naifold capillaroscopy in mixed connective tissue disease patients

INTRODUCTION

Mixed connective tissue disease (MCTD) is a rare systemic disease characterized by overlapping features of systemic lupus erythematosus (SLE), systemic sclerosis (SSc), dermato-/polymyositis (DM/PM), and rheumatoid arthritis (RA). Naifold capillaroscopy (NFC) is a non-invasive test for evaluating the capillaries of the nail shaft used in the diagnosis of rheumatic diseases.

OBJECTIVES

To determine whether there are characteristic abnormalities in NFC in MCTD patients, and whether the type of NFC lesions correlates with organ involvement in these patients.

METHODS

Clinical picture and NFC patterns were analyzed in 43 patients with MCTD. Capillaroscopic images were divided into scleroderma-like pattern (SD-like pattern) according to the Cutolo classification, non-specific lesions, and normal images. Relationships between the clinical aspects considered in the MCTD classification criteria and the changes in the capillaroscopic images were evaluated.

RESULTS

SD-like pattern was present in 20 MCTD patients (46.51%) with a predominance of the "early" pattern. Giant, branched, dilated capillaries and reduced capillary density were found more frequently in MCTD patients compared to the control group (p-values 0.0005, 0.005, 0.02, < 0.0001 respectively). There were associations found between the presence of a reduced number of vessels, avascular areas, and SD-like pattern with the presence of sclerodactyly in MCTD patients (p = 0.002, p = 0.006, p = 0.02, respectively), alongside an association between the presence of branched vessels and the subpapillary plexus with pulmonary arterial hypertension (PAH) (p = 0.04 and p = 0.005, respectively).

CONCLUSIONS

MCTD patients are significantly more likely to have abnormalities upon NFC. It is worthwhile to perform capillaroscopic examination in MCTD patients. Key Points • Scleroderma-like pattern was found in more than half of the MCTD patients. • Reduced capillary density was found to be a significant predictor of the diagnosis of MCTD. • There were relationships between the presence of reduced capillary density, avascular areas, and SD-like with the presence of sclerodactyly in the MCTD patients. • There was an association between the presence of branched vessels and the visibility of the subpapillary plexus and pulmonary arterial hypertension (PAH).

Screening, diagnosis, and monitoring of interstitial lung disease in autoimmune rheumatic diseases: A narrative review

Interstitial lung disease (ILD) is a common and serious manifestation of autoimmune rheumatic diseases. While the prevalence of ILD differs among the individual autoimmune rheumatic diseases, ILD remains an important cause of morbidity and mortality in systemic sclerosis, systemic lupus erythematosus, mixed connective tissue disease, primary Sjögren's disease, rheumatoid arthritis, and idiopathic inflammatory myositis. The present review summarizes recent literature on autoimmune-associated ILD with a focus on screening and monitoring for ILD progression. Reflecting on the currently available evidence, the authors propose a guideline for monitoring for progression in patients with newly diagnosed autoimmune-associated ILD. This review also highlights clinical and biological predictors of progressive pulmonary fibrosis and describes opportunity for further study in the rapidly evolving area of rheumatology and pulmonology.

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.

Mixed Connective Tissue Disease: The Two Cases Representing the Range of this Illness

INTRODUCTION

Mixed connective tissue disease (MCTD) is defined as a systemic rheumatic disease characterized by the presence of high titer anti-U1 ribonucleoprotein (U1 RNP) antibodies in combination with clinical features commonly seen in systemic lupus erythematosus (SLE), systemic sclerosis (SSc), rheumatoid arthritis (RA) and polymyositis (PM).

CASE PRESENTATION

The annual incidence of MCTD is 1.9 per 100,000 adults. Any organ system can be involved in MCTD however four clinical features that suggest the presence of MCTD rather than another systemic rheumatic disease are Raynaud phenomenon with swollen hands or puffy fingers, absence of severe kidney disease and central nervous system (CNS) disease at first presentation generally, insidious onset of pulmonary hypertension and presence of autoantibodies anti-U1 ribonucleoprotein (U1 RNP), especially antibodies to the 68 kD protein. MCTD, although initially thought to be a disease with a benign course is not considered a valid argument at present. This connective tissue disorder can present with life-threating organ involvement with rapid progression of disease.

CONCLUSION

We report two cases of MCTD, one with mild disease and another with life-threatening illness, describing the range of severity at presentation of this disorder.

Pulmonary hypertension in connective tissue diseases: epidemiology, pathogenesis, and treatment

Pulmonary hypertension (PH) is a clinical condition characterized by increased pulmonary arterial pressure arising from a heterogeneous range of diseases that has a deteriorating effect on the quality of life and may cause early mortality if left untreated. Connective tissue disorders (CTD)-associated PH is the second most common cause of pulmonary arterial hypertension (PAH), after the idiopathic form, categorized as group I. Systemic scleroderma (SSc) accounts for 75% of CTD-associated PH cases. Although SSc ranks first place for CTD-associated PH, SSc is followed by systemic lupus erythematosus (SLE) and mixed connective tissue disease (MCTD), having a lesser frequency of PH occurrence, while it occurs as a rare complication in cases with rheumatoid arthritis (RA) and inflammatory myositis. PH may also occur during non-SSc CTDs and even other rheumatic diseases, including Behcet's disease and adult-onset Still's disease, albeit to a lesser extent. The prognosis of CTD-associated PH is worse than the other forms of PH. Although, as in idiopathic pulmonary arterial hypertension (IPAH), the mechanism of CTD-related PH is associated with an increase in vasoconstrictors like endothelin-1 and a decrease in vasodilators like prostacyclin and nitric oxide production, inflammation, and autoimmune mechanisms also play a role in the development and progression of PH. This may lead to the involvement of more than one mechanism in CTD-associated PH. Knowing which mechanism is dominant is very important in determining the treatment option. This review will primarily focus on the epidemiology, risk factors, and prognosis of PH that develops during rheumatic diseases; the pathogenesis and treatment will be briefly mentioned in light of the newly published guidelines. Key Points • Pulmonary arterial hypertension (PAH) associated with connective tissue disease (CTD) in Western countries is the second most common type of PAH after idiopathic PAH (IPAH). • CTD-PH can be seen most often in systemic scleroderma (SSc), less in systemic lupus erythematosus (SLE), mixed CTD (MCTD), and rarely in other CTDs. • While current guidelines recommend annual transthoracic echocardiography as a screening test for asymptomatic SSc patients, screening for PH is not advised in the absence of symptoms suggestive of PH in other CTDs. • CTD-PH treatment can be divided into specific vasodilator PH treatments and immunosuppressive therapy. Current treatment guidelines recommend the same treatment algorithm for patients with CTD-associated PH as for patients with IPAH. Several case series have shown the beneficial effect of immunosuppressive agents in patients with SLE-PH and MCTD-PH.

Joint and muscle inflammatory disease: A scoping review of the published evidence

OBJECTIVES

Polyarthritis is commonly reported in idiopathic inflammatory myositis patients, but few studies have focused on the overlap of myositis with rheumatoid arthritis which is a difficult diagnosis in the absence of well-defined diagnostic criteria. The primary objective of this scoping review was to map the field of research to explore the potential diagnoses in patients presenting with both myositis and polyarthritis.

METHODS

Two electronic databases (MEDLINE/PubMed® and Web of Science®) were systematically searched using the terms (myositis OR 'inflammatory idiopathic myopathies') AND (polyarthritis OR 'rheumatoid arthritis') without any publication date limit.

RESULTS

Among individual records, 280 reports met inclusion criteria after full-text review. There was heterogeneity in the definition of overlap myositis as well as the characteristics of rheumatoid arthritis. In many studies, key data were lacking; rheumatoid factor status was reported in 56.8% (n=151), anti-citrullinated proteins antibodies status in 18.8% (n=50), and presence or absence of bone erosions in 45.1% (n=120) of the studies. Thirteen different diagnoses were found to associate myositis with polyarthritis: antisynthetase syndrome (29.6%, n=83), overlap myositis with rheumatoid arthritis (16.1%, n=45), drug-induced myositis (20.0%, n=56), rheumatoid myositis (7.5%, n=21), inclusion body myositis (1.8%, n=5), overlap with connective tissue disease (20.0%, n=56), and others (5.0%, n=14).

CONCLUSION

The spectrum of joint and muscle inflammatory diseases encompasses many diagnoses including primitive and secondary myositis associated with RA or arthritis mimicking RA. This review highlights the need for a consensual definition of OM with RA to better individualise this entity from the numerous differential diagnoses.

Skin disorders and interstitial lung disease: Part II-The spectrum of cutaneous diseases with lung disease association

Part 2 of this 2-part CME introduces dermatologists to noninfectious inflammatory skin diseases associated with pulmonary involvement. In many cases, dermatologists may be the first physicians recognizing respiratory complications associated with these diagnoses. Because pulmonary involvement is often the leading cause of morbidity and mortality, dermatologists should be comfortable screening and monitoring for lung disease in high-risk patients, recognizing cutaneous stigmata of lung disease in these patients and referring to pulmonary specialists, when appropriate, for prompt treatment initiation. Some treatments used for skin disease may not be appropriate in the context of lung disease and hence, choosing a holistic approach is important. Interstitial lung disease and pulmonary hypertension are the most common pulmonary complications and a significant cause of mortality in autoimmune connective tissue diseases, especially systemic sclerosis, dermatomyositis, and mixed connective tissue disease. Pulmonary complications, notably interstitial lung disease, are also common and life-threatening in sarcoidosis and vasculitis, while they are variable in neutrophilic and autoimmune blistering diseases.

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.

A Man With Malaise, Myalgia, and Rapidly Progressive Interstitial Lung Disease

A 45-year-old man sought treatment at the ED during the third wave of the COVID-19 pandemic with a month-long history of fatigue, cough, myalgia, and hand stiffness. He did not report dyspnea. He had no past medical history and previously was fit and active, working as a farmer. He was a lifelong nonsmoker and had no family history of lung disease.

Phenotypic clusters and survival analyses in interstitial pneumonia with myositis-specific autoantibodies

Background:

Idiopathic inflammatory myopathy (IIM) is highly combined with interstitial pneumonia (IP), often as the initial or solo presentation with positive myositis-specific autoantibodies (MSAs) but does not fulfill the diagnostic criteria.

Objectives:

We aimed to explore the phenotypic clusters and prognosis of the patients with IP and positive MSA, which is called MSA-IP in the present study.

Methods:

A total of 178 patients with MSA-IP were prospectively enrolled for analysis. Serum MSAs were detected using Western blotting. Radiological patterns of IP were determined according to the classification of idiopathic IPs. Clusters of patients with MSA-IP were identified using cluster analysis. Predictors for acute/subacute onset, therapeutic response, IP progression and survival were also analyzed.

Results:

Patients with MSA-IP were classified into four distinct clusters. Cluster 1 were the elderly with chronic onset, nearly normal oxygenation and good survival. Cluster 2 had dyspnea on exertion and nonspecific IP pattern, with moderate survival. Patients in cluster 3 had chronic onset and were prone to IP progression (OR 2.885). Cluster 4 had multi-systemic involvements, positive anti-melanoma differentiation associated gene 5 antibody, and were prone to acute/subacute onset (OR 3.538) and IP progression (OR 5.472), with poor survival. Corticosteroids combined immunosuppressants showed therapeutic response in MSA-IP (OR 4.303) and had a protective effect on IP progression (OR 0.136).

Conclusions:

Four clusters of the patients with MSA-IP suggested the distinct clinical, radiological and prognostic features.

Relationship between type of skin lesions and nailfold capillaroscopy pattern in mixed connective tissue disease

INTRODUCTION

Mixed connective tissue disease (MCTD) is a rare disease with clinical picture consisted of multiple organ manifestations, including skin changes resembling systemic lupus erythematosus (SLE), systemic sclerosis (SSc), or dermatomyositis (DM). On the background of these manifestations are microvascular changes - alteration of endothelial function and impairment of endothelial progenitor cell. Nailfold capillaroscopy (NFC) is a simple, non-invasive technique for investigating microvascular involvement in rheumatic diseases.

OBJECTIVES

To describe the relationship between type of skin lesions and NFC pattern in MCTD patients.

METHODS

We analyzed the clinical picture and NFC patterns in 79 patients with MCTD. The NFC changes were classified into Normal, "Early," "Active," and "Late" scleroderma-like patterns (SD-like pattern) based on Cutolo classification. In all patients, subjective and physical examinations were carried out, specifically the occurrence of skin lesions in the course of MCTD was assessed (systemic sclerosis-like (Ssc-like), systemic lupus erythematosus-like (SLE-like), dermatomysitis-like (DM-like)).

RESULTS

Skin changes were present in 64 (81%) patients, involving 43 (54%) SLE-like, 48 (61%) SSc-like, and 4 (5.1%) DM-like. NFC changes were observed in a total of 55 (69.6 %) patients with predominance of the "Early" pattern - 41 (51.9 %) patients. According to skin change phenotypes, NFC changes were observed in 31 (72%) patients with SLE-like and in 32 (66.7%) patients with SSc-like skin phenotypes. The "early" pattern predominated in both group.

CONCLUSIONS

We did not find any correlation between NFC pattern and the type skin changes. Key Points • The study did not show a correlation between the presence and absence of skin lesions and NFC pattern. • Scleroderma-like patterns were found in over 60% of patients with mixed connective tissue disease. • The "early" pattern is dominant regardless of the occurrence or absence of skin lesions in patients with MCTD. • Skin lesions, regardless of their type (SLE or SSc), do not correlate with type of lesion found in the NFC examination.

Pulmonary Hypertension Associated with Connective Tissue Disease

Pulmonary hypertension (PH), a syndrome characterized by elevated pulmonary pressures, commonly complicates connective tissue disease (CTD) and is associated with increased morbidity and mortality. The incidence of PH varies widely between CTDs; patients with systemic sclerosis are most likely to develop PH. Several different types of PH can present in CTD, including PH related to left heart disease and respiratory disease. Importantly, CTD patients are at risk for developing pulmonary arterial hypertension, a rare form of PH that is associated with high morbidity and mortality. Future therapies targeting pulmonary vascular remodeling may improve outcomes for patients with this devastating disease.

Interstitial Lung Disease in Connective Tissue Diseases: Survival Patterns in a Population-Based Cohort

Objectives: Interstitial lung disease (ILD) is associated with impaired survival among patients with connective tissue diseases (CTDs), but population-based data on the frequency of ILD and pulmonary hypertension (PH) in different CTD subtypes and the impact on survival are sparse. Methods: We included patients with a first-time ICD-10 diagnosis of systemic sclerosis (SSc), mixed connective tissue disease (MCTD), myositis, systemic lupus erythematosus (SLE), or Sjögren’s disease registered in the Danish National Patient Registry between 2000 and 2015. Among these, we identified patients with ILD and PH. Using Kaplan–Meier analysis, we assessed survival for the five subtypes of CTD ± ILD and compared survival among CTD patients overall ± ILD with survival in the general population ± ILD. Results: We identified 11,731 patients with a diagnosis of CTD; 637 (5.4%) had a diagnosis of ILD. The proportion of patients with ILD was higher in SSc (13.4%) and MCTD (9.1%) than in myositis (6.0%), SLE (4.1%), and Sjögren (2.8%). Fifty-one percent were diagnosed with ILD in their fifties and sixties. PH was more frequent in SSc (7.5%) and MCTD (4.1%). Five-year survival was 73.3% (66.7–80.6) in SSc-ILD, 81.0% (69.0–95.1) in MCTD-ILD, 84.7% (77.3–92.9) in myositis-ILD, 83.5% (76.2–91.5) in SLE-ILD, and 84.7 (78.4–91.6) in Sjögren-associated ILD. Survival in CTD-ILD overall was impaired for all age groups compared with CTD alone. Age-stratified survival was comparable between CTD-ILD and ILD in the general population. The survival gap between ILD and non-ILD increased with age. Conclusion: Survival was comparable between different CTD-ILD subtypes and comparable to survival in non-CTD-ILD.

Group 3 Pulmonary Hypertension: A Review of Diagnostics and Clinical Trials

Group 3 pulmonary hypertension (PH) is a known sequelae of chronic lung disease. Diagnosis and classification can be challenging in the background of chronic lung disease and often requires expert interpretation of numerous diagnostic studies to ascertain the true nature of the PH. Stabilization of the underlying lung disease and adjunctive therapies such as oxygen remain the mainstays of therapy, as there are no Food and Drug Administration-approved therapies for group 3 PH. Referral to PH centers for individualized management and clinical trial enrollment is paramount.

The other connective tissue disease-associated interstitial lung diseases: Sjogren's syndrome, mixed connective tissue disease, and systemic lupus erythematosus

PURPOSE OF REVIEW

We review the clinical manifestations of three less common connective tissue disease (CTD)-associated interstitial lung diseases (ILDs): Sjogren's syndrome (SjS), mixed CTD (MCTD), and systemic lupus erythematosus (SLE).

RECENT FINDINGS

SjS is classically associated with lymphocytic interstitial pneumonia and cystic lung disease, but the most common type of ILD in Sjogren's patients is nonspecific interstitial pneumonia. ILD is prevalent in MCTD and associated with worse survival. SLE-associated ILD, while rare, is more common in those with CTD overlap syndromes. Regardless of underlying cause, a subset of patients with fibrotic CTD-associated ILD develop a progressive course for which antifibrotic agents and lung transplantation should be considered.

SUMMARY

An understanding of the characteristics of ILD in SjS, MCTD, and SLE is important for the pulmonary specialist. Future research should identify risk factors for progression and develop additional treatment modalities for both CTD-related autoimmune features and progressive ILD.

Connective Tissue Diseases in the Skin: Emerging Concepts and Updates on Molecular and Immune Drivers of Disease

Cutaneous manifestations are common across the spectrum of autoimmune diseases. Connective tissue diseases manifesting in the skin are often difficult to classify and require integration of clinical, histopathologic, and serologic findings. This review focuses on the current understanding of the molecular and immune drivers involved in the pathogenesis of cutaneous lupus erythematosus, dermatomyositis, scleroderma/systemic sclerosis, and mixed connective tissue disease. Recent research advances have led to the emergence of new ancillary tools and useful diagnostic clues of which dermatopathologists should be aware to improve diagnostic accuracy for these diseases.

"Mixed connective tissue disease": a condition in search of an identity

Mixed connective tissue disease was first described as a new autoimmune rheumatic disease in 1972 based on the claim of a distinct clinical picture associated with anti-RNP antibody positivity. Subsequently, this new entity has divided opinions in the rheumatology community. We have reviewed recent cohort studies with more than 100 patients, comparing the clinical and immunological features, treatment, prognosis and evolution to well-defined autoimmune rheumatic diseases. We also reviewed clinical features of undifferentiated autoimmune rheumatic diseases based on the most recent studies. After gathering and reviewing these data, we discuss whether the designation “mixed connective tissue disease” should be maintained.

Inflammatory Myopathy-Related Interstitial Lung Disease: From Pathophysiology to Treatment

Inflammatory myopathies (IM) are auto-immune connective tissue diseases characterized by muscle involvement and by extramuscular manifestations. As such, pulmonary manifestations, which mainly include interstitial lung disease (ILD), often darken two out of four distinct IM, namely dermatomyositis and overlapping myositis. Being the initiation site of the disease and being the leading cause of morbidity and mortality, ILD is of major importance in this context. ILD has a heterogeneous expression among the patients, with various onset mode, various radiological pattern, various severity and finally with different prognoses, which are particularly difficult to predict at the time of IM diagnosis. Therefore, ILD is a challenging issue. Treatments are based on steroids and immunosuppressive or targeted therapies. Their respective place is yet poorly codified however and remains often based on clinician expertise. Dedicated clinical trials are lacking to date and are also difficult to build, due to difficulty of constituting large and homogeneous patient groups and to rigorously evaluate disease outcomes. Indeed, pulmonary function tests alone are being regularly defeated in IM, in which respiratory muscles are often involved. Composite scores, bringing together several lung parameters, should thus be developed and validated in the future, to better assess the disease response to treatment. This review aims to describe the current knowledge of IM immuno-pathogenesis, the clinical features associated with IM related-ILD, focusing of both severity and prognosis, and the actual therapeutic approaches.

Phenotypes Determined by Cluster Analysis and Their Survival in the Prospective European Scleroderma Trials and Research Cohort of Patients With Systemic Sclerosis

Objective

Systemic sclerosis (SSc) is a heterogeneous connective tissue disease that is typically subdivided into limited cutaneous SSc (lcSSc) and diffuse cutaneous SSc (dcSSc) depending on the extent of skin involvement. This subclassification may not capture the entire variability of clinical phenotypes. The European Scleroderma Trials and Research (EUSTAR) database includes data on a prospective cohort of SSc patients from 122 European referral centers. This study was undertaken to perform a cluster analysis of EUSTAR data to distinguish and characterize homogeneous phenotypes without any a priori assumptions, and to examine survival among the clusters obtained.

Methods

A total of 11,318 patients were registered in the EUSTAR database, and 6,927 were included in the study. Twenty‐four clinical and serologic variables were used for clustering.

Results

Clustering analyses provided a first delineation of 2 clusters showing moderate stability. In an exploratory attempt, we further characterized 6 homogeneous groups that differed with regard to their clinical features, autoantibody profile, and mortality. Some groups resembled usual dcSSc or lcSSc prototypes, but others exhibited unique features, such as a majority of lcSSc patients with a high rate of visceral damage and antitopoisomerase antibodies. Prognosis varied among groups and the presence of organ damage markedly impacted survival regardless of cutaneous involvement.

Conclusion

Our findings suggest that restricting subsets of SSc patients to only those based on cutaneous involvement may not capture the complete heterogeneity of the disease. Organ damage and antibody profile should be taken into consideration when individuating homogeneous groups of patients with a distinct prognosis.

Identification of 6 dermatomyositis subgroups using principal component analysis-based cluster analysis

OBJECTIVE

Dermatomyositis (DM) is a heterogeneous disease with a wide range of clinical manifestations. The aim of the present study was to identify the clinical subtypes of DM by applying cluster analysis.

METHODS

We retrospectively reviewed the medical records of 720 DM patients and selected 21 variables for analysis, including clinical characteristics, laboratory findings, and comorbidities. Principal component analysis (PCA) was first conducted to transform the 21 variables into independent principal components. Patient classification was then performed using cluster analysis based on the PCA-transformed data. The relationships among the clinical variables were also assessed.

RESULTS

We transformed the 21 clinical variables into nine independent principal components by PCA and identified six distinct subgroups. Cluster A was composed of two sub-clusters of patients with classical DM and classical DM with minimal organ involvement. Cluster B patients were older and had malignancies. Cluster C was characterized by interstitial lung disease (ILD), skin ulcers, and minimal muscle involvement. Cluster D included patients with prominent lung, muscle, and skin involvement. Cluster E contained DM patients with other connective tissue diseases. Cluster F included all patients with myocarditis and prominent myositis and ILD. We found significant differences in treatment across the six clusters, with clusters E, C and D being more likely to receive aggressive immunosuppressive therapy.

CONCLUSION

We applied cluster analysis to a large group of DM patients and identified 6 clinical subgroups, underscoring the need for better phenotypic characterization to help develop individualized treatments and improve prognosis.

Contribution of pulmonary function tests (PFTs) to the diagnosis and follow up of connective tissue diseases

Introduction

Connective Tissue Diseases (CTDs) are systemic autoimmune conditions characterized by frequent lung involvement. This usually takes the form of Interstitial Lung Disease (ILD), but Obstructive Lung Disease (OLD) and Pulmonary Artery Hypertension (PAH) can also occur. Lung involvement is often severe, representing the first cause of death in CTD. The aim of this study is to highlight the role of Pulmonary Function Tests (PFTs) in the diagnosis and follow up of CTD patients.

Main body

Rheumatoid Arthritis (RA) showed mainly an ILD with a Usual Interstitial Pneumonia (UIP) pattern in High-Resolution Chest Tomography (HRCT). PFTs are able to highlight a RA-ILD before its clinical onset and to drive follow up of patients with Forced Vital Capacity (FVC) and Carbon Monoxide Diffusing Capacity (DL_CO). In the course of Scleroderma Spectrum Disorders (SSDs) and Idiopathic Inflammatory Myopathies (IIMs), DL_CO appears to be more sensitive than FVC in highlighting an ILD, but it can be compromised by the presence of PAH. A restrictive respiratory pattern can be present in IIMs and Systemic Lupus Erythematosus due to the inflammatory involvement of respiratory muscles, the presence of fatigue or diaphragm distress.

Conclusions

The lung should be carefully studied during CTDs. PFTs can represent an important prognostic tool for diagnosis and follow up of RA-ILD, but, on their own, lack sufficient specificity or sensitivity to describe lung involvement in SSDs and IIMs. Several composite indexes potentially able to describe the evolution of lung damage and response to treatment in SSDs are under investigation. Considering the potential severity of these conditions, an HRCT jointly with PFTs should be performed in all new diagnoses of SSDs and IIMs. Moreover, follow up PFTs should be interpreted in the light of the risk factor for respiratory disease related to each disease.

Overlap myositis, a distinct entity beyond primary inflammatory myositis: A retrospective analysis of a large cohort from the REMICAM registry

BACKGROUND

Inflammatory idiopathic myositis (IIM) comprises a heterogeneous group of systemic muscular diseases that can occur together with other connective tissue diseases (CTD), named overlap myositis (OM). The question of whether OM is a distinct entity still remains controversial.

AIM

The present study was conducted to assess the clinical and prognostic differences between patients diagnosed with OM, primary polymyositis (PM) and primary dermatomyositis (DM).

METHOD

The study consists of a retrospective longitudinal and multicenter series of IIM patients. Patients were classified as OM, PM and DM. Overlap myositis was defined as patients fulfilling criteria for IIM plus criteria for other CTD (namely systemic sclerosis, systemic lupus erythematosus, mixed connective tissue disease, rheumatoid arthritis and primary Sjögren's syndrome).

RESULT

A total of 342 patients were included (98 OM, 137 PM and 107 DM). Overlap myositis patients, in comparison with PM and DM, showed significant differences, with more extramuscular involvement, particularly more arthritis (66%, 34.6% and 48.1%, respectively), puffy fingers (49.5%, 11.1% and 24.3%), sclerodactyly (45.4%, 2.2% and 2%), dysphagia (41.8%, 18.2% and 26.4%), Raynaud phenomenon (65.3%, 16.9% and 19.8%), leucopenia (28.9%, 2.2% and 8.4%), thrombocytopenia (8.2%, 2.2% and 1.9%), interstitial lung disease (ILD) (48%, 35% and 30.8%), renal manifestations (13.4%, 3.7% and 1.9%), and more severe infections (41.3%, 26.7% and 21%). No significant differences were found in survival between groups in log rank test (P = 0.106). Multivariate adjusted survival analyses revealed a worse prognosis for severe infections, ILD and baseline elevation of acute phase reactants.

CONCLUSION

Overlap myositis stands out as a distinct entity as compared to PM and DM, featuring more extramuscular involvement and more severe infections. Close monitoring is recommended in this subset for early detection and treatment of possible complications.

Treatment consensus for management of polymyositis and dermatomyositis among rheumatologists, neurologists and dermatologists

Although rheumatologists, neurologists and dermatologists see patients with polymyositis (PM) and dermatomyositis (DM), their management appears to vary depending on the physician's specialty. The aim of the present study was to establish the treatment consensus among specialists of the three fields to standardize the patient care. We formed a research team supported by a grant from the Ministry of Health, Labor and Welfare, Japan. Clinical questions (CQ) on the management of PM and DM were raised. A published work search on CQ was performed primarily using PubMed. Using the nominal group technique, qualified studies and results in the published work were evaluated and discussed to reach consensus recommendations. They were sent out to the Japan College of Rheumatology, Japanese Society of Neurology and Japanese Dermatological Association for their approval. We reached a consensus in 23 CQ and made recommendations and a decision tree for management was proposed. They were officially approved by the three scientific societies. In conclusion, a multidisciplinary treatment consensus for the management of PM and DM was established for the first time.

Comparison of articular manifestations of mixed connective tissue disease and systemic lupus erythematosus on clinical examination and musculoskeletal ultrasound

BACKGROUND

Polyarthritis is common to both mixed connective tissue disease (MCTD) and systemic lupus erythematosus (SLE). Apart from being erosive and deforming in the former, we speculated that it was more common and the extent of joints involved would be higher in MCTD.

METHODS

This was a cross-sectional study that included patients with MCTD aged 18-75 years fulfilling the Kasukawa criteria. An equal number of patients with SLE matched for disease duration and gender were included. Clinical manifestations were compared between patients with MCTD and with SLE. Examination of joints was done for the presence of tenderness or swelling and deformity. Musculoskeletal ultrasound was done on the non-dominant hand for detection of synovitis and tenosynovitis and radiographs of the hands were obtained. The use of methotrexate and non-steroidal anti-inflammatory drugs (NSAIDs) for arthritis was noted. Statistical tests used were non-parametric.

RESULTS

Forty patients with MCTD and forty patients with SLE were included in this study, with patients being slightly older in MCTD than SLE (36 ± 10.2, 31.8 ± 13.3 years, p = 0.01). There were no significant differences in disease duration (4.7 ± 3.1, 3.7 ± 2.3, p = 0.1) or gender (females = 38, 38). Nearly one-half of patients with MCTD had at least one swollen joint compared with only 15% of patients with SLE. Median (95% confidence interval) tender joint count (5 (4.8-10.4), 0 (1.3-7.2), p = 0.01) and swollen joint count (0 (0.9-2.6), 0 (0-1.2), p = 0.002) was significantly higher in patients with MCTD compared with SLE. More patients with MCTD than SLE had tender or swollen proximal interphalangeal joints (12, 4, p = 0.025). More patients with MCTD than SLE had received methotrexate (8,2, p = 0.04) and NSAIDs (39, 32, p = 0.03) for arthritis. There was no difference in the number of patients with MCTD or SLE who had evidence of synovitis or tenosynovitis on ultrasound. There was no difference in erosive disease on hand radiographs, but acro-osteolysis was higher among MCTD patients.

CONCLUSIONS

A higher proportion of patients with MCTD had at least one swollen and tender joint as compared with patients with SLE, as well as higher use of methotrexate and NSAIDs. However, there was no difference in ultrasound detected synovitis or tenosynovitis.

Systemic Lupus Erythematosus, Sjögren Syndrome, and Mixed Connective Tissue Disease in Children and Adolescents

Juvenile systemic lupus erythematosus (jSLE), mixed connective tissue disease (jMCTD), and Sjögren syndrome (jSS) are systemic autoimmune and inflammatory disorders with distinct patterns of organ involvement. All are characterized by autoantibody formation, with antinuclear (ANA) and anti-double-stranded DNA common in jSLE, ANA with high-titer ribonucleoprotein antibody in jMCTD, and Sjögren syndrome A and Sjögren syndrome B antibodies + ANA in jSS. Recognition, monitoring, and management for primary care providers are discussed, focusing on the role of primary physicians in recognizing and helping maintain optimal health in children with these potentially life-threatening diseases.

An Autoimmune Basis for Raynaud's Phenomenon: Murine Model and Human Disease

OBJECTIVE

Raynaud's phenomenon (RP) is common in anti-RNP-positive patients with rheumatic diseases but is not itself known to be caused by autoimmunity. The aim of this study was to assess autoantibodies that could mediate this process.

METHODS

Antibodies derived from patient sera and from murine models of anti-RNP autoimmunity were screened for the ability to induce RP-like tissue ischemia and endothelial cell apoptosis in murine models and in vitro systems.

RESULTS

RNP-positive sera from RP patients and murine sera from RNP-positive B cell adoptive transfer recipients induced RP-like tissue ischemia and endothelial cell apoptosis. Proteomic analysis identified cytokeratin 10 (K10) as a candidate autoantigen in RP. Monoclonal anti-K10 antibodies reproduced patterns of ischemic tissue loss and endothelial cell apoptosis; K10 knockout or depletion of anti-K10 activity in serum was protective. Cold exposure enhanced K10 expression and in vivo tissue loss.

CONCLUSION

Anti-K10 antibodies are sufficient to mediate RP-like ischemia in murine models and are implicated in the pathogenesis of RP in patients with anti-RNP autoimmunity.

Progression and mortality of interstitial lung disease in mixed connective tissue disease: a long-term observational nationwide cohort study

Objectives

To assess the prevalence, extent, progression, functional impact and mortality of interstitial lung disease (ILD) in a nationwide unselected MCTD cohort.

Methods

The study cohort included patients with high-resolution CT lung scans available at baseline (n = 135) and at follow-up (n = 119). The extent of disease was expressed as percentage of total lung volume (TLV).

Results

ILD was present in 41% of MCTD patients at follow-up. Median (interquartile) extent (% of TLV) was 5 (8) at baseline and 7 (17) at follow-up, mean length 6.4 years later. The lung disease progressed in 19% of patients across the observation period. Predictors of ILD progression were elevated anti-RNP titre [hazard ratio (HR) 1.5, 95% CI: 1.1, 2.0; P = 0.008], presence of anti-ro52 antibodies (HR = 3.5, 95% CI: 1.2, 10.2; P = 0.023), absence of arthritis (HR = 0.2, 95% CI: 0.1, 0.6; P = 0.004) and male gender (HR = 4.0, 95% CI: 1.4, 11.5; P = 0.011) after age and baseline disease adjustments. The risk of death increased by 2.9 (95% CI: 1.1, 7.9; P = 0.038) in patients where disease involved ⩾5% of TLV.

Conclusion

Lung disease extent and progression in MCTD are modest. Yet, the extension continues several years after MCTD diagnosis causing lung function decline and increasing the risk of mortality. The study identified male gender, elevated anti-RNP titre, presence of anti-ro52 antibodies and absence of arthritis as the strongest predictors of ILD progression.

Disease evolution in mixed connective tissue disease: results from a long-term nationwide prospective cohort study

Background

The phenotypic stability of mixed connective tissue disease (MCTD) is not clear, and knowledge about disease activity and remission is scarce. We aimed to establish the occurrence of evolution from MCTD to another defined rheumatic condition, and the prevalence and durability of remission after long-term observation.

Methods

In this large population-based prospective observational MCTD cohort study (N = 118), disease conversion was defined by the development of new auto-antibodies and clinical features compliant with another well-defined rheumatic condition. Remission was defined by a combination of systemic lupus erythematosus disease activity index 2000 (SLEDAI-2 K) of 0 and European League Against Rheumatism scleroderma trials and research (EUSTAR) activity index <2.5. Predictors of phenotypic stability and disease remission were assessed by logistic regression.

Results

Among 118 patients, 14 (12%) developed another well-defined rheumatic condition other than MCTD after mean disease duration of 17 (SD 9) years. Puffy hands predicted a stable MCTD phenotype in univariable regression analysis (OR 7, CI 2–27, P = .010). Disease activity defined by SLEDAI-2 K, decreased gradually across the observation period and > 90% of patients had EUSTAR activity index <2.5. There were 13% patients in remission throughout the whole mean observation period of 7 (SD 2) years. The strongest predictor of remission was percentage of predicted higher forced vital capacity.

Conclusions

Our results strengthen the view of MCTD as a relatively stable disease entity. Long-term remission in MCTD is not frequent; however, the low SLEDAI-2 K and EUSTAR scores during the observation period suggests that the disease runs a milder course than systemic lupus erythematosus and systemic sclerosis.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-017-1494-7) contains supplementary material, which is available to authorized users.

Facts and controversies in mixed connective tissue disease

Mixed connective tissue disease (MCTD) is a systemic autoimmune rheumatic disease (SARD) characterised by the combination of clinical manifestations of systemic lupus erythematosus (SLE), cutaneous systemic sclerosis (SSc) and polymyositis-dermatomyositis, in the presence of elevated titers of anti-U1-RNP antibodies. Main symptoms of the disease are polyarthritis, hand oedema, Raynaud's phenomenon, sclerodactyly, myositis and oesophageal hypomobility. Although widely discussed, most authors today accept MCTD as an independent entity. Others, however, suggest that these patients may belong to subgroups or early stages of certain definite connective diseases, such as SLE or SSc, or are, in fact, SARD overlap syndromes.

Mixed connective tissue disease-enigma variations?

In 1972, Sharp et al. described a new autoimmune rheumatic disease that they called MCTD, characterized by overlapping features of SSc, SLE, PM/DM, high levels of anti-U1snRNP and low steroid requirements with good prognosis. MCTD was proposed as a distinct disease. However, soon after the original description, questions about the existence of such a syndrome as well as disputes over the features initially described began to surface. The conundrum of whether MCTD is a distinct disease entity remains controversial. We undertook a literature review, focusing on the articles reporting new data about MCTD published in the last decade, to determine whether any new observations help to answer the conundrum of MCTD. After reviewing recent data, we question whether the term MCTD is appropriately retained, preferring to use the term undifferentiated autoimmune rheumatic disease.

Associated Variables of Myositis in Systemic Lupus Erythematosus: A Cross-Sectional Study

BACKGROUND This study aimed to estimate the point prevalence of myositis and identify associated variables of myositis in systemic lupus erythematosus (SLE). MATERIAL AND METHODS Clinical date of patients hospitalized with lupus at the First Affiliated Hospital of Anhui Medical University and Anhui Provincial Hospital were collected. Patients were defined as having myositis if they reported the presence of persistent invalidating muscular weakness combined with increased levels of creatine phosphokinase (CPK) and abnormal electromyography (EMG). RESULTS The study sample comprised 1701 lupus patients, of which 44 had myositis. Patients with SLE-associated myositis are more likely to have skin rash, alopecia, pericarditis, vasculitis, anti-Sm, anti-RNP, anti-dsDNA, thrombocytopenia, leukopenia, low C3, low C4, high erythrocyte sedimentation rate (ESR), high D-dimer, and active disease. Multivariate logistic regression found positive associations between leukopenia, alopecia, and active disease with myositis. Negative associations between myositis with the use of corticosteroids or immunosuppressive drugs were revealed in univariate and multivariate analysis. CONCLUSIONS The point prevalence of myositis was 2.6% in SLE patients. The significant association of alopecia, leukopenia, and active disease with myositis suggests that organ damage, hematological abnormality, and high disease activity promote the progression of myositis in lupus patients.

Pediatric Mixed Connective Tissue Disease

Pediatric-onset mixed connective tissue disease is among the rare disease entities in pediatric rheumatology and includes features of arthritis, polymyositis/dermatomyositis, systemic lupus erythematosus, and systemic sclerosis. Accurate recognition and diagnosis of the disease is paramount to prevent long-term morbidity. Advances in the genetic and immunologic understanding of the factors involved in the etiopathogenesis provide an opportunity for improvements in prognostication and targeted therapy. The development of a multinational cohort of patients with mixed connective tissue disease would be invaluable to provide more updated data regarding the clinical presentation, to develop a standardized treatment approach, disease activity and outcome tools, and to provide data on long-term outcomes and comorbidities.

Can SLE classification rules be effectively applied to diagnose unclear SLE cases?

Objective The objective of this paper is to develop novel classification criteria to distinguish between unclear systemic lupus erythematosus (SLE) and mixed connective tissue disease (MCTD) cases. Methods A total of 205 variables from 111 SLE and 55 MCTD patients were evaluated to uncover unique molecular and clinical markers for each disease. Binomial logistic regressions (BLRs) were performed on currently used SLE and MCTD classification criteria sets to obtain six reduced models with power to discriminate between unclear SLE and MCTD patients that were confirmed by receiving operating characteristic (ROC) curve. Decision trees were employed to delineate novel classification rules to discriminate between unclear SLE and MCTD patients. Results SLE and MCTD patients exhibited contrasting molecular markers and clinical manifestations. Furthermore, reduced models highlighted SLE patients exhibiting prevalence of skin rashes and renal disease while MCTD cases show dominance of myositis and muscle weakness. Additionally decision tree analyses revealed a novel classification rule tailored to differentiate unclear SLE and MCTD patients (Lu-vs-M) with an overall accuracy of 88%. Conclusions Validation of our novel proposed classification rule (Lu-vs-M) includes novel contrasting characteristics (calcinosis, CPK elevated and anti-IgM reactivity for U1-70K, U1A and U1C) between SLE and MCTD patients and showed a 33% improvement in distinguishing these disorders when compared to currently used classification criteria sets. Pending additional validation, our novel classification rule is a promising method to distinguish between patients with unclear SLE and MCTD diagnosis.

Management of interstitial lung disease associated with connective tissue disease

The lung is a common site of complications of systemic connective tissue disease (CTD), and lung involvement can present in several ways. Interstitial lung disease (ILD) and pulmonary hypertension are the most common lung manifestations in CTD. Although it is generally thought that interstitial lung disease develops later on in CTD it is often the initial presentation ("lung dominant" CTD). ILD can be present in most types of CTD, including rheumatoid arthritis, scleroderma, systemic lupus erythematosus, polymyositis or dermatomyositis, Sjögren's syndrome, and mixed connective tissue disease. Despite similarities in clinical and pathologic presentation, the prognosis and treatment of CTD associated ILD (CTD-ILD) can differ greatly from that of other forms of ILD, such as idiopathic pulmonary fibrosis. Pulmonary hypertension (PH) can present as a primary vasculopathy in pulmonary arterial hypertension or in association with ILD (PH-ILD). Therefore, detailed history, physical examination, targeted serologic testing, and, occasionally, lung biopsy are needed to diagnose CTD-ILD, whereas both non-invasive and invasive assessments of pulmonary hemodynamics are needed to diagnose pulmonary hypertension. Immunosuppression is the mainstay of treatment for ILD, although data from randomized controlled trials (RCTs) to support specific treatments are lacking. Furthermore, treatment strategies vary according to the clinical situation-for example, the treatment of a patient newly diagnosed as having CTD-ILD differs from that of someone with an acute exacerbation of the disease. Immunosuppression is indicated only in select cases of pulmonary arterial hypertension related to CTD; more commonly, selective pulmonary vasodilators are used. For both diseases, comorbidities such as sleep disordered breathing, symptoms of dyspnea, and cough should be evaluated and treated. Lung transplantation should be considered in patients with advanced disease but is not always feasible because of other manifestations of CTD and comorbidities. Clinical trials of novel therapies including immunosuppressive therapies are needed to inform best treatment strategies.

Venous and Arterial Thrombotic Events in Systemic Lupus Erythematosus

Objective.

The incidence of thrombosis in patients with systemic lupus erythematosus (SLE) is 25 to 50-fold higher than in the general population; we aimed to define the characteristics of venous thrombotic events (VTE) and arterial thrombotic events (ATE) to identify the patients at highest risk.

Methods.

The study included 219 patients with recent-onset SLE. At baseline, standardized medical history and laboratory tests were done. Followup visits occurred quarterly, and information about damage accrual, comorbidities, and cardiovascular risk factors was updated annually. Main outcome was development of TE after SLE diagnosis.

Results.

Thirty-five patients (16%) developed TE (27 VTE, 8 ATE) during 5.21 years of followup; incidence rate 31/1000 patient-years. Most events (57%) developed within the first year of diagnosis, and 69% were not associated with lupus anticoagulant (LAC), determined with 1 method. VTE developed earlier than ATE (2.0 vs 57.5 mos, p = 0.02). In the multivariate analysis, variables preceding VTE included cutaneous vasculitis, nephrotic syndrome, dose of prednisone, and LAC in combination with anti-RNP/Sm antibodies (p < 0.03). Patients with ATE were older (median age 44 vs 29 yrs, p = 0.04), smokers, and had hypertension, diabetes mellitus, dyslipidemia, at least 2 traditional risk factors, nephrotic syndrome, chronic damage, and a higher cumulative dose of prednisone (p < 0.05). LAC in combination with anti-RNP/Sm antibodies was associated with VTE and improved the accuracy for predicting it.

Conclusion.

Our study suggests that in SLE, VTE and ATE have different risk factors. Understanding these differences is helpful for identifying patients at highest risk. The use of LAC plus anti-RNP/Sm for predicting VTE deserves further study.

Associations between circulating endostatin levels and vascular organ damage in systemic sclerosis and mixed connective tissue disease: an observational study

Introduction

Systemic sclerosis (SSc) and mixed connective tissue disease (MCTD) are chronic immune-mediated disorders complicated by vascular organ damage. The aim of this study was to examine the serum levels of the markers of neoangiogenesis: endostatin and vascular endothelial growth factor (VEGF), in our unselected cohorts of SSc and MCTD.

Methods

Sera of SSc patients (N = 298) and MCTD patients (N = 162) from two longitudinal Norwegian cohorts were included. Blood donors were included as controls (N = 100). Circulating VEGF and endostatin were analyzed by enzyme immunoassay.

Results

Mean endostatin levels were increased in SSc patients 93.7 (37) ng/ml (P < .001) and MCTD patients 83.2 (25) ng/ml (P < .001) compared to controls 65.1 (12) ng/ml. Median VEGF levels were elevated in SSc patients 209.0 (202) pg/ml compared to MCTD patients 181.3 (175) pg/ml (P = .017) and controls 150.0 (145) pg/ml (P < .001). Multivariable analysis of SSc subsets showed that pulmonary arterial hypertension (coefficient 15.7, 95 % CI: 2.2–29.2, P = .023) and scleroderma renal crisis (coefficient 77.6, 95 % CI: 59.3–100.0, P < .001) were associated with elevated endostatin levels. Multivariable analyses of MCTD subsets showed that digital ulcers were associated with elevated endostatin levels (coefficient 10.5, 95 % CI: 3.2–17.8, P = .005). The risk of death increased by 1.6 per SD endostatin increase (95 % CI: 1.2–2.1, P = .001) in the SSc cohort and by 1.6 per SD endostatin increase (95 % CI: 1.0–2.4, P = .041) in the MCTD cohort after adjustments to known risk factors.

Conclusions

Endostatin levels were elevated in patients with SSc and MCTD, particularly SSc patients with pulmonary arterial hypertension and scleroderma renal crisis, and MCTD patients with digital ulcers. Elevated endostatin levels were also associated with increased all-cause mortality during follow-up in both groups of patients. We propose that endostatin might indicate the degree of vascular injury in SSc and MCTD patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-015-0756-5) contains supplementary material, which is available to authorized users.

Increased levels of anti-heat-shock protein 60 (anti-Hsp60) indicate endothelial dysfunction, atherosclerosis and cardiovascular diseases in patients with mixed connective tissue disease

Heat-shock protein 60 (Hsp60) has been shown to provoke inflammation, and anti-Hsp60 may facilitate the development of atherosclerosis. In this study, we have investigated 30 patients with mixed connective tissue disease (MCTD) and assessed anti-Hsp60 and their relationship to cardiovascular diseases (CVD). Out of 30 patients with MCTD, 15 had CVDs. Anti-Hsp60 antibody was determined by enzyme-linked immunosorbent assay. Since endothelial dysfunction and accelerated atherosclerosis are characteristic to MCTD, a wide array of MCTD-, endothelial dysfunction- and CVD-associated parameters was investigated: serum lipid levels, paraoxonase activity (PON1), rich nuclear ribonucleoprotein U1 (anti-U1RNP), anti-endothelial cell antibodies, anti-cardiolipin and anti-β2-glycoprotein I antibody isotypes (anti-CL and anti-β2GPI), endothelin-1 (ET-1) levels, also intima-media thickness (IMT), a quantitative indicator of atherosclerosis. In MCTD, anti-Hsp60 antibody levels were significantly higher than in healthy individuals (p < 0.02). MCTD patients with CVD had significantly higher levels of anti-Hsp60 compared to MCTD without CVD (p = 0.001). Patients with MCTD had significantly lower high-density lipoprotein cholesterol (p = 0.02) and PON activity (p < 0.001), and significantly increased systolic (p < 0.0002) and diastolic (p < 0.001) blood pressure compared to healthy individuals. Anti-U1RNP levels (p < 0.002) and IMT were higher in patients compared to controls (p = 0.002). The CVD-positive MCTD patients had increased anti-Hsp60 (p < 0.0013), anti-CL IgG (p = 0.0005), ET-1 serum concentration (p < 0.05) and IMT levels (p < 0.001) compared to MCTD patients without CVD. Anti-Hsp60 showed a strong correlation with anti-oxLDL (r = 0.36, p = 0.01) and serum ET-1 (r = 0.62, p < 0.001) and negative correlation with PON activity (r = -0.47, p = 0.01). Anti-Hsp60 indicates endothelial injury, CVD, and can function as a novel atherosclerotic risk factor, also a valuable diagnostic marker in patients with MCTD.

[Vascular endothelial injury induced by anti-endothelial cell antibody in allogeneic hematopoietic stem cell transplantation]

OBJECTIVE

To clarify the role of endothelial cells (ECs) injury induced by anti-endothelial cell antibody (AECA) in allogeneic hematopoietic stem cell transplantation (allo-HSCT).

METHODS

Serum immunoglobulin (IgG) from allo-HSCT recipients were purified and incubated with human umbilical vein vascular endothelium (HUVEC) in vitro, then the functional changes and cell apoptosis were tested.

RESULTS

After incubation with AECA positive IgG, soluble adhesion molecules significantly elevated in culture supernatant. When concentration of IgG was 160, 320, and 640 μg/ml, concentrations of soluble intercellular adhesion molecule-1 in supernatant were statistically higher in AECA positive groups [(117.10 ± 12.82) vs (78.17 ± 4.90) pg/ml, (151.30 ± 15.35) vs (89.46 ± 6.02) pg/ml, (239.00 ± 32.53) vs (127.80 ± 13.86) pg/ml, P<0.01)]. When concentration of IgG was 40, 80, 160, 320, and 640 μg/ml, concentrations of soluble vascular cell adhesion molecule-1 in supernatant were also statistically higher in AECA positive groups [(38.51 ± 3.76) vs (24.78 ± 2.59) pg/ml, (61.34 ± 6.99) vs (38.20 ± 3.17) pg/ml, (135.60 ± 24.46) vs (63.73 ± 5.08) pg/ml, (221.30 ± 29.40) vs (112.80 ± 8.91) pg/ml, (420.90 ± 31.70) vs (224.40 ± 20.79) pg/ml, P<0.01]. Clotting activity factors also elevated in culture supernatant after incubation with AECA positive IgG. When concentration of IgG was 80, 160, 320, and 640 μg/ml, concentrations of von Willebrand factor were statistically higher in AECA positive groups [(19.51 ± 0.72) vs (17.17 ± 0.60) ng/ml, P=0.0193; (22.97 ± 1.18) vs (18.27 ± 0.61) ng/ml, (26.40 ± 1.54) vs (19.53 ± 0.70) ng/ml, (34.35 ± 1.60) vs (23.81 ± 0.92) ng/ml, P<0.01]. When concentration of IgG was 320 and 640 μg/ml, concentrations of thrombomodulin were statistically higher in AECA positive groups [(57.50 ± 4.50) vs (40.31 ± 4.39) pg/ml, P=0.0132; (59.18 ± 4.11) vs (38.84 ± 5.16) pg/ml, P<0.01]. However, inflammatory factors (IL-1β, IL-6, IL-8 and ANG2) were not statistically different in AECA positive and negative groups (P>0.05). Moreover, IgG from AECA positive samples did not change the proliferation or cell apoptosis.

CONCLUSION

AECA from allo-HSCT recipients dysregulates ECs' function in vitro, but do not induce apoptosis, which is valuable in the pathophysiology of graft-versus-host disease (GVHD) and other complications after allo-HSCT.

Diagnosis and risk stratification in patients with anti-RNP autoimmunity

INTRODUCTION

Anti-RNP autoantibodies occur either in mixed connective tissue disease (MCTD) (with a frequently favorable prognosis), or in systemic lupus erythematosus (SLE) cases with aggressive major organ disease. It is uncertain how to assess for the risk of severe disease in anti-RNP + patients.

METHODS

Following institutional review board-approved protocols, clinical data and blood were collected from patients with known or suspected anti-RNP autoimmunity and normal controls in a cohort study. Samples were screened for parameters of immune activation. Groups were compared based on clinical diagnoses, disease classification criteria, disease activity and specific end-organ clinical manifestations.

RESULTS

Ninety-seven per cent of patients satisfying Alarcon-Segovia MCTD criteria also met Systemic Lupus International Collaborating Clinic (SLICC) SLE criteria, while 47% of the anti-RNP + SLE patients also met MCTD criteria. Among SLICC SLE patients, MCTD criteria were associated with reduced rates of renal disease (odds ratio (OR) 4.3, 95% confidence interval (CI) 1.3-14.0), increased rates of Raynaud's phenomenon (OR 3.5, 95% CI 1.3-9.5) and increased serum B-cell maturation antigen, transmembrane activator and CAML interactor and TNFα levels. Circulating immune markers and markers of type I interferon activation were not effective at distinguishing clinical subgroups.

CONCLUSIONS

Among anti-RNP patients, the question of MCTD versus SLE is not either/or: most MCTD patients also have lupus. MCTD classification criteria (but not a broad set of immune markers) distinguish a subset of SLE patients at reduced risk for renal disease.

Pulmonary manifestations of Sjögren syndrome, systemic lupus erythematosus, and mixed connective tissue disease

Interstitial lung disease is a common and often life-threatening manifestation of different connective tissue disorders, often affecting its overall prognosis. Systemic lupus erythematosus, Sjögren syndrome, and mixed connective tissue disease, although all unique diseases, can have lung manifestations as an important part of these conditions. This article reviews the different pulmonary manifestations seen in these 3 systemic rheumatologic conditions.