Lung involvement in systemic sclerosis (scleroderma): relation to classification based on extent of skin involvement or autoantibody status

Agreement Between Physician Evaluation and the Composite Response Index in Diffuse Cutaneous Systemic Sclerosis

OBJECTIVE

Diffuse cutaneous systemic sclerosis (SSc) is a highly heterogeneous disease. A provisionally approved Composite Response Index in diffuse cutaneous SSc (CRISS) was developed as a 1-year outcome measure for clinical trials. Our goal was to further validate the CRISS by examining agreement between CRISS definitions for improved/non-improved with physicians' evaluation of disease.

METHODS

Patient profiles from a large observational cohort were created for 50 random diffuse cutaneous SSc patients of <5 years disease duration with improved CRISS scores after 1 year and 50 with non-improved CRISS scores. Profiles described disease features used during the initial CRISS development at baseline and at 1 year. Each profile was independently rated by 3 expert physicians. Majority opinion determined whether a patient was improved or not improved, and kappa agreement with the CRISS cutoff of 0.6 was calculated.

RESULTS

Patients had mean ± SD disease duration of 2.2 ± 1.3 years. There was substantial agreement between the physician majority opinion about each case and the CRISS (κ = 0.76 [95% confidence interval (95% CI) 0.64-0.88]). The agreement between each individual physician opinion and the CRISS was also substantial (κ = 0.70 [95% CI 0.62-0.78]). All CRISS non-improvers were also rated as non-improved by physician majority; however, 12 CRISS improvers were rated as non-improved by physicians.

CONCLUSION

There was substantial agreement between the dichotomous CRISS rating and physician assessment of diffuse cutaneous SSc patients after 1 year. This supports the use of a CRISS cutoff at 0.6 for improvement versus non-improvement, although the CRISS tended to rate more patients as improved than did physicians.

Toward Molecular Stratification and Precision Medicine in Systemic Sclerosis

Systemic sclerosis (SSc), a complex multi-systemic disease characterized by immune dysregulation, vasculopathy and fibrosis, is associated with high mortality. Its pathogenesis is only partially understood. The heterogenous pathological processes that define SSc and its stages present a challenge to targeting appropriate treatment, with differing treatment outcomes of SSc patients despite similar initial clinical presentations. Timing of the appropriate treatments targeted at the underlying disease process is critical. For example, immunomodulatory treatments may be used for patients in a predominantly inflammatory phase, anti-fibrotic treatments for those in the fibrotic phase, or combination therapies for those in the fibro-inflammatory phase. In advancing personalized care through precision medicine, groups of patients with similar disease characteristics and shared pathological processes may be identified through molecular stratification. This would improve current clinical sub-setting systems and guide personalization of therapies. In this review, we will provide updates in SSc clinical and molecular stratification in relation to patient outcomes and treatment responses. Promises of molecular stratification through advances in high-dimensional tools, including omic-based stratification (transcriptomics, genomics, epigenomics, proteomics, cytomics, microbiomics) and machine learning will be discussed. Innovative and more granular stratification systems that integrate molecular characteristics to clinical phenotypes would potentially improve therapeutic approaches through personalized medicine and lead to better patient outcomes.

Correlation Between Skin and Affected Organs in 52 Sclerodermic Patients Followed in a Diseases Management Team: Development of a Risk Prediction Model of Organ-Specific Complications

Objective

To identify the existence of a correlation among the various organs affected, focusing primarily on immuno-dermatological aspects, and to create a risk prediction model of organ-specific complications.

Material and Methods

Fifty-two patients with stable scleroderma, followed between 2015 and 2019, were investigated through an extensive multidisciplinary evaluation in the last year.

Results

Patients with lung involvement presented a worse degree of skin fibrosis than patients without it (p <0.001). No relationship was observed for the heart, kidney, and esophagus. Patients with pulmonary involvement had a lower pressure of the low esophagus sphincter and a higher Warrick score than patients without it (p <0.05). Age was significantly higher in patients with kidney involvement. Diffuse scleroderma patients had a worse pulmonary impairment than limited scleroderma patients (p <0.05). The manometric "sclerodermic" pattern was observed to be the most frequent (55.6%, p <0.05) in dcSSc patients while the sclerodermic and normal pattern were equally represented (41.2 and 32.4% respectively, p <0.05) in lcSSc patients. When compared to the negative serological groups, anti-Scl-70 positive patients presented a worse lung involvement while anti-centromere patients presented a better lung outcome (p <0.05). PM-Scl 100/75 positive patients presented mostly a pulmonary fibrotic pattern (p <0.05) and, also, heart complications were more likely associated with anti PM-Scl 100/75 positivity (p <0.05). The risk prediction model for organ-specific complications had an accuracy of 84.4% (95%CI 78, 89) in complication-site prediction, AUC of 0.871, 86% of sensitivity, and 83% of specificity, Cohen's Kappa (k) of 0.68.

Conclusions

Out of all the organs studied, the skin is the one that correlates with the lung. Patients with a diffuse form of disease presented more frequently the anti Scl-70 antibody and had a worse lung and esophageal involvement (scleroderma pattern) than the negative group. Conversely, patients with limited disease presented all positive for the anti-centromere antibody with a better lung involvement than the negative group, without any difference among the esophageal manometric pattern. Anti PM-Scl 100/75 antibody patients were associated with pulmonary fibrosis and presented cardiac involvement. The model created has demonstrated excellent values of sensitivity, specificity, and accuracy, but further studies are needed for validation.

Systemic sclerosis: To subset or not to subset, that is the question

Systemic sclerosis (SSc) is a heterogeneous disease with variability in autoantibody profiles, skin and internal organ involvement, disease trajectory, and survival. The ability to identify more homogeneous subsets of SSc patients has informed patient care and been an essential aspect of SSc research. In this article, the historic evolution of subsetting systems in SSc are described including clinically based SSc subsetting systems, their utility, strengths, and limitations. There is a shifting paradigm of SSc subsets, including biologic classification of SSc subsets and fully data-driven approaches to SSc subset classification, taking into consideration the needs of the SSc global community in the modern era and the ability to prognosticate patients with SSc.

Determinants of mortality in systemic sclerosis: a focused review

Scleroderma (systemic sclerosis) is an autoimmune rheumatic disorder that is characterized by fibrosis, vascular dysfunction, and autoantibody production that involves most visceral organs. It is characterized by a high morbidity and mortality rate, mainly due to disease-related complications. Epidemiological data describing mortality and survival in this population have been based on both population and observational studies. Multiple clinical and non-clinical factors have been found to predict higher likelihood of death among thepatients. Here, we do an extensive review of the available literature, utilizing the PubMed database, to describe scleroderma and non-scleroderma related determinants of mortality in this population. We found that even though the mortality among the general population has declined, scleroderma continues to carry a very high morbidity and mortality rate, however we have made some slow progress in improving the mortality among scleroderma patients over the last few decades.

Six-Minute Walk Test as a Predictor of Diagnosis, Disease Severity, and Clinical Outcomes in Scleroderma-Associated Pulmonary Hypertension: The DIBOSA Study

BACKGROUND

Pulmonary hypertension (PH) is a common complication of scleroderma (SSc) and is a leading cause of morbidity and mortality.

OBJECTIVES

To explore the utility of the 6MWT in the prediction of SSc-PH and to assess its prognostic implications.

METHODS

A retrospective review of SSc patients from 2003 to 2013, with 6MWT and echocardiogram (n = 286), was conducted. Presence of PH was defined by right heart catheterization. Patients were randomized into development and validation cohorts. Using regression techniques, we developed a scoring system to predict the presence of SSc-PH and tested it in our validation cohort. Trends of mortality and disease severity were studied for incremental scores.

RESULTS

The DIBOSA scoring system includes DIstance walked in 6 min, BOrg dyspnea index, and SAturation of oxygen at 6 min. The DIBOSA score in the development cohort ranged from 0 to 3, resulting in an area of 0.858 (P < 0.0001) under the ROC curve. A score of 0 had a NPV of 100% and a score of 3 had a PPV of 86.58%. The validation cohort had an area under the ROC curve of 0.842. The DIBOSA score correlated with both pulmonary artery pressures and mortality. The 3-year survival rates for DIBOSA scores of 0, 1, 2, and 3 were 100, 100, 87.67, and 66.67%, respectively (HR = 3.92, P < 0.0001).

CONCLUSIONS

DIBOSA score is a sensitive tool for the prediction of SSc-PH. The DIBOSA score is a direct predictor of mortality in SSc-PH and strongly correlates with pulmonary pressures. 6MWT can be used to predict clinical outcomes in SSc-PH.

Controversies: molecular vs. clinical systemic sclerosis classification

Systemic sclerosis (SSc) is a multisystem chronic disease characterized by the three cardinal pathological features, including autoimmunity/inflammation, vasculopathy, and fibrosis, with unknown etiology. Individual patients manifest these three components to variable degrees, resulting in the diverse heterogeneity of clinical presentation. The classification of SSc patients into relatively homogenous subtypes is helpful in the setting of daily clinical practice and the field of clinical and basic research. The classification of SSc has been continuously discussed over four decades based on the clinical and laboratory features, especially the extent of skin sclerosis and disease-related autoantibodies. This clinical classification system enables clinicians to provide general advice regarding prognosis and risk for internal organ disease, but only permits estimates of outcomes informed by population-based studies. On the other hand, the recent decade has seen much progress in the understanding of molecular aspects of SSc complex pathology, raising a discussion on molecular classification of SSc. The development of molecular targeting therapies, especially biologics, further strengthens the importance of molecular classification which aids the identification of potential responders for each treatment. Although a careful validation study is required for molecular classification of SSc due to its large heterogeneity, the advance of molecular classification would introduce a further modification into SSc classification system in the near future. Importantly, clinical and molecular classifications are not mutually exclusive, therefore the combination would facilitate the development of a better classification system of this complex heterogeneous disorder that is useful in both the clinical setting and research studies.

Pulmonary involvement in systemic sclerosis: A clinical profile

Background:

Systemic sclerosis is a generalized disorder of connective tissue affecting skin and internal organs. Lung involvement accounts for significant morbidity and is a leading cause of mortality in patients.

Objectives:

This study intends to study the frequency of occurrence of pulmonary involvement in progressive systemic sclerosis (PSS) and to describe the clinical and radiological picture of pulmonary involvement in PSS.

Materials and Methods:

This was a descriptive cross-sectional study. A detailed history, modified Rodnan score, clinical examination, routine investigation, antinuclear antibody, immuno biot, chest X-ray (CXR), pulmonary function test (PFT), and 6 min walk test (6MWT) were performed on all patients. High resolution computed tomography was done on those who consented.

Results:

Hundred subjects with PSS were included in the study; 90 were females and 10 were males. Common presenting complaints were skin thickening in 98% and Raynaud's phenomenon in 98%. Skin thickening of digits beyond metacarpo phalangeal was seen in 98%, face and neck in 92%, and hands in 92%. Chest wall thickening was seen in 40 subjects (40%). 90 (90%) of the studied subjects had pulmonary involvement, longer duration of disease was significantly associated with pulmonary involvement (P < 0.05). Dyspnea, cough, bilateral crepitations, CXR, Borg score, and Rodnan score was found to be significantly associated with severe pulmonary involvement (P < 0.05).

Conclusion:

The prevalence of pulmonary involvement in this cohort study was 90%. Almost 1/3^rd of patients, that is 29 (29%) were detected to have pulmonary involvement despite being asymptomatic for respiratory complaints, hence early screening and evaluation is recommended. PFT and 6MWT are noninvasive, cost-effective, and easily available screening tests which can be used in resource-limited settings.

Clinical differences between Thai systemic sclerosis patients with positive versus negative anti-topoisomerase I

BACKGROUND

Anti-topoisomerase I antibody (ATA) carries an increased risk of systemic sclerosis (SSc) internal organ involvement. There have been no published comparisons of the clinical characteristics of patients positive and negative for ATA in Thailand, where the positive rate for ATA is higher than among Caucasians.

OBJECTIVE

To define the clinical differences between SSc, positive versus negative, for ATA.

METHODS

A retrospective cohort study was performed among SSc patients over 18 at Srinagarind Hospital, Khon Kaen University, Thailand, during January 2006-December 2013. SSc-overlap syndrome was excluded.

RESULTS

Two hundred and ninety-four SSc patients were included (female : male 2.5 : 1). The majority (68.6%) were the diffuse cutaneous SSc subset (dcSSc). ATA was positive in 252 patients (85.7%), among whom 71.7% had dcSSc and 28.2% limited cutaneous SSc (lcSSc). Using a multivariate analysis, hand deformity had a significantly positive association with ATA (odds ratio [OR] 7.01; 95% CI 1.02-48.69), whereas being anti-centromere (ACA) positive had a negative association (OR 0.17; 95% CI 0.03-0.92). After doing a subgroup analysis of the SSc subset, the median duration of disease at time of pulmonary fibrosis detection among ATA positive dcSSc was significantly shorter than the ATA negative group (1.05 vs. 6.77 years, P = 0.01). Raynaud's phenomenon (RP) at onset was significantly more frequent in lcSSc sufferers who were ATA negative than those who were ATA positive (90.5% vs. 56.9%, P = 0.005).

CONCLUSIONS

A high prevalence of ATA positivity was found among Thai SSc patients and this was associated with a high frequency of hand deformity, ACA negativity, a short duration of pulmonary fibrosis in dcSSc and a lower frequency of RP in lcSSc.

Influence of interstitial lung disease on outcome in systemic sclerosis: a population-based historical cohort study

BACKGROUND

Interstitial lung disease (ILD) is a frequent complication of systemic sclerosis (SSc) and a major cause of SSc-related deaths. This study aimed to determine the influence of ILD on SSc in a population-based historical cohort study. The hypothesis was that patients with SSc who develop ILD have increased morbidity and mortality when compared with patients with SSc without ILD.

METHODS

Using the record linkage system of the Rochester Epidemiology Project in Olmsted County, Minnesota, this study identified the incidence of SSc between 1980 and 2010 and point prevalence on December 31, 2010 and determined the progression of organ involvement and its influence on outcome.

RESULTS

During the 30-year interval, we identified 64 incident cases of SSc: 57 women and seven men, median age 49.1 years (interquartile range [IQR], 39.8-67.6 years). There were 43 prevalent cases. ILD occurred in 19 cases, usually after the diagnosis of SSc (median, 2 years; IQR, 0-10 years), with only three cases occurring 6 to 24 months beforehand. Pulmonary arterial hypertension (PAH) was diagnosed in 14 cases, heart failure in 27 cases, and chronic kidney disease (CKD) in 21 cases. Seventeen patients died during the study period, with a median survival time after diagnosis of 22.9 years. ILD, PAH, and CKD were associated with an increased risk of death.

CONCLUSIONS

The incidence of ILD associated with SSc was relatively low in this population-based cohort. ILD appeared to be a contributing factor to mortality. Other factors, including age, PAH, and CKD, were also associated with poor outcome.

The degree of skin involvement identifies distinct lung disease outcomes and survival in systemic sclerosis

OBJECTIVE

To determine whether the pattern of skin involvement can predict clinical features, risk of restrictive lung disease (RLD) and survival in a large scleroderma (SSc) cohort.

METHODS

Demographic and clinical data collected over 30 years from 2205 patients with SSc were retrospectively analysed after subdividing subjects into four subtypes based on pattern of skin fibrosis: type 0 (no skin involvement), type 1 (limited to metacarpophalangeal joints), type 2 (distal to elbows/knees) and type 3 (proximal to elbows/knees). Clinical features associated with skin subsets were identified by regression analyses. Kaplan-Meier and Cox proportional hazards models were used to compare time to RLD and survival across subtypes.

RESULTS

The presence and severity of RLD were positively associated with skin subtype (p<0.001). RLD prevalence incrementally ranged from 51.9% in type 0 to 76.7% in type 3 (p<0.001). Type 2 SSc exhibited a distinct phenotype with intermediate risk for RLD relative to type 1 (higher, p<0.001) and type 3 (lower, p<0.001) and a unique autoantibody profile, with a prevalence of anticentromere antibodies lower than type 1 (28.9% vs 44.1%, p=0.001) and of anti-topoisomerase I antibodies similar to type 3 (32.8% vs 28.7%, p=0.38). These autoantibodies were also found to be significant negative (OR=0.33, p<0.001) and positive (OR=1.6, p=0.01) predictors of RLD risk, respectively. Mortality was also intermediate in type 2 patients relative to type 3 (p=0.0003) and type 1 (p=0.066).

CONCLUSIONS

These data suggest that the current classification subdividing SSc into limited and diffuse cutaneous subtypes misclassifies an intermediate group of patients exhibiting unique autoantibody profile, disease course and clinical outcomes.

The pulmonary fibrosis-associated MUC5B promoter polymorphism does not influence the development of interstitial pneumonia in systemic sclerosis

BACKGROUND

More than 80% of patients with systemic sclerosis (SSc) develop lung involvement, most commonly interstitial pneumonia (IP). We recently identified a common variant in the promoter region of MUC5B (rs35705950) that has a significant effect on the risk of developing both familial and sporadic forms of IP. We hypothesized that this MUC5B promoter polymorphism is also associated with IP in subjects with SSc.

METHODS

We examined the minor allele frequency of the MUC5B polymorphism among 231 subjects with SSc, 109 with IP, and 122 without IP. IP diagnosis was confirmed by HRCT imaging and defined as the presence of reticular infiltrates and/or honeycomb cysts. FVC and diffusing capacity of the lung for carbon monoxide (Dlco) were also assessed.

RESULTS

We found no association between IP and the MUC5B polymorphism among subjects with SSc (OR = 1.1, P = .80). The frequencies of the MUC5B polymorphism among subjects with SSc with IP (10.6%) and without IP (9.4%) were similar to the frequency observed in a population of unaffected control subjects (9.0%). In secondary analyses, we found the MUC5B polymorphism was not significantly associated with either FVC (P = .42) or Dlco (P = .06). No association with SSc-associated IP was found even when we used a more conservative definition of IP (FVC ≤ 70% and evidence of reticulations or honeycombing vs SSc FVC &gt; 70% and no evidence of reticulation or honeycombing).

CONCLUSIONS

Although SSc-associated IP is clinically, radiologically, and histologically similar to other forms of IP, it appears to have distinct genetic risk factors. This study highlights the genetic and phenotypic heterogeneity of IP in general.

Association of gastroesophageal factors and worsening of forced vital capacity in systemic sclerosis

OBJECTIVE

Interstitial lung disease (ILD) is a common complication of systemic sclerosis (SSc) and causes death. Once lung fibrosis occurs, disease course may become stable or decline. Little is known about risks for progression. We studied SSc-gastroesophageal (GE) involvement in relation to worsening forced vital capacity (FVC) on pulmonary function tests (PFT) to investigate whether it was related to progression. Our objective was to determine whether GE reflux and dysphagia are associated with progressive moderate/severe ILD as measured by PFT over 3 years.

METHODS

The Canadian Scleroderma Research Group is a multicenter SSc database that collects data annually. Using indicators of GE involvement and annual PFT, comparisons were made between no/mild ILD, stable moderate/severe ILD, and progressive moderate/severe ILD groups based on changes of FVC. Multivariate analyses determined associations between GE factors and ILD development and progression.

RESULTS

There were 1043 patients with SSc (mean age 55.7 yrs, mean disease duration 10.8 yrs); one-quarter had pulmonary fibrosis on chest radiograph that was related to FVC percentage predicted (Spearman's rho -0.39; p < 0.01). Physician indicators such as esophageal dysmotility (p = 0.009) and postesophageal dilatation (p = 0.041), and patient indicators such as difficulty swallowing (p = 0.016) and waking up choking (p = 0.026) were associated with low FVC. In comparing progressive and stable moderate/severe FVC (< 70% predicted), early satiety (p = 0.018) and a combination term of postdilatation and choking (p = 0.042) increased risk of progression of ILD. Topoisomerase I was not associated with progression over followup.

CONCLUSION

Symptoms of esophageal dysmotility were associated with worsening FVC in SSc, especially if both need for esophageal dilatation and choking were present.

Scleroderma lung disease

Pulmonary involvement is second in frequency only to esophageal involvement as a visceral complication of systemic sclerosis (SSc) and has surpassed renal involvement as the most common cause of death. Interstitial lung disease and pulmonary vascular disease, particularly pulmonary arterial hypertension, are the most commonly encountered types of lung involvement. Chronic aspiration, airway disease, neuromuscular weakness, extrinsic pulmonary restrictive pathology, pleural effusions, pneumothorax, and lung cancer cause clinically significant disease and occur commonly enough to be routinely considered in the assessment of the SSc patient with respiratory symptoms. Affected patients have a significantly worse prognosis than patients with SSc who are free of pulmonary involvement.

Pulmonary manifestations of scleroderma and mixed connective tissue disease

Pulmonary manifestations are common in connective tissue diseases, and are associated with significant morbidity and mortality in this patient population. Systemic sclerosis (SSc) and mixed connective tissue disease (MCTD) are clinical entities for which the detection of lung involvement is essential to improve patient care and outcomes. This article discusses the pathogenesis, clinical presentation, and evaluation of the patient with pulmonary disease related to SSc and MCTD, with an emphasis on interstitial lung disease and pulmonary hypertension.

Pulmonary arterial hypertension associated with systemic sclerosis

Systemic sclerosis (SSc) is commonly complicated by pulmonary arterial hypertension (PAH), which is a leading cause of death in the SSc patient population. Owing to the fact that the risk of developing pulmonary hypertension is high, screening is important, although the optimal modality remains to be defined. Furthermore, despite recent advances in therapy for PAH, the response to these interventions in patients with PAH with SSc has been discouraging. The lack of clinical response to these therapies may merely reflect the limitations of traditionally employed PAH outcome measures in SSc-PAH patients or highlight the heterogeneity of the disease manifestations within SSc. Importantly, since extrapulmonary involvement of the GI tract and kidneys by SSc limit candidacy for lung transplantation, new therapies that target abnormal cellular proliferation in the pulmonary vasculature are currently under investigation and may be particularly relevant to SSc-PAH.

Lung involvement in systemic sclerosis

Scleroderma is a multisystem disease characterized by a severe inflammatory process and exuberant fibrosis. Lung involvement is a frequent complication and a leading cause of morbidity and mortality in this syndrome. Two major pulmonary syndromes are associated with scleroderma; a pulmonary vascular disorder evolving over time into relatively isolated pulmonary arterial hypertension (PAH), and interstitial lung disease (ILD). Each syndrome, when present, is a cause of morbidity and significantly reduces survival of scleroderma patients when compared to patients free of lung complication. When pulmonary hypertension and ILD are combined, survival is further reduced. Current therapy appears to have no meaningful effect on either condition and, thus, there is a need for better understanding of underlying pathogenic mechanisms. This review focuses on clinical, diagnostic, and therapeutic features of PAH and ILD as well as other frequent but less debilitating lung complications of scleroderma.

Interstitial lung disease in connective tissue diseases: evolving concepts of pathogenesis and management

Interstitial lung disease (ILD) is a challenging clinical entity associated with multiple connective tissue diseases, and is a significant cause of morbidity and mortality. Effective therapies for connective tissue disease-associated interstitial lung disease (CTD-ILD) are still lacking. Multidisciplinary clinics dedicated to the early diagnosis and improved management of patients with CTD-ILD are now being established. There is rapid progress in understanding and identifying the effector cells, the proinflammatory and profibrotic mediators, and the pathways involved in the pathogenesis of CTD-ILD. Serum biomarkers may provide new insights as risk factors for pulmonary fibrosis and as measures of disease progression. Despite these recent advances, the management of patients with CTD-ILD remains suboptimal. Further studies are therefore urgently needed to better understand these conditions, and to develop effective therapeutic interventions.

Gene profiling of scleroderma skin reveals robust signatures of disease that are imperfectly reflected in the transcript profiles of explanted fibroblasts

OBJECTIVE

To determine whether biopsy specimens obtained from systemic sclerosis (SSc) lesions show a distinctive gene profile, whether that gene profile is maintained in fibroblasts cultured from SSc skin biopsy specimens, and whether results from tissue obtained from multiple clinical centers can be combined to yield useful observations in this rare disease.

METHODS

Biopsy samples and passaged fibroblasts were stored in RNAlater solution prior to processing for RNA. RNA from SSc and control skin biopsy specimens, as well as SSc and control explanted passage 4 fibroblasts, from 9 patients and 9 controls was hybridized to Affymetrix HG-U133A arrays. Data were analyzed using the BRB ArrayTools system. When appropriate, findings were followed up with immunohistochemical analysis or TaqMan studies.

RESULTS

Biopsy samples obtained from patients with SSc had a robust and distinctive gene profile, with approximately 1,800 qualifiers distinguishing normal skin from SSc skin at a significant level. The SSc phenotype was the major driver of sample clusters, independent of origin. Alterations in transforming growth factor beta and Wnt pathways, extracellular matrix proteins, and the CCN family were prominent. Explanted fibroblasts from SSc biopsy samples showed a far smaller subset of changes that were relatively variable between samples, suggesting that either nonfibroblast cell types or other aspects of the dermal milieu are required for full expression of the SSc phenotype.

CONCLUSION

SSc has a distinct gene profile that is not confounded by geographic location, indicating that extended multicenter studies may be worthwhile to identify distinct subsets of disease by transcript profiling. Explanted SSc fibroblasts show an incomplete reflection of the SSc phenotype.

Different clinical features in patients with limited and diffuse cutaneous systemic sclerosis

This study aims to analyze differences among established disease damage indicators in patients with limited cutaneous systemic sclerosis (lcSSc) and diffuse cutaneous systemic sclerosis (dcSSc). Fifty patients with lcSSc and 55 patients with dcSSc were included in this study. Difference in mean disease duration between the two subgroups of patients was not statistically significant (z=-0.88, p=0.38). Patients with lcSSc and dcSSc were compared, and differences in vascular, esophageal, lung, heart, renal, and musculoskeletal involvement were statistically assessed using chi (2), Mann-Whitney, and Kruskal-Wallis tests. Using the technique of nailfold capillaroscopy, we found normal capillaries or nonspecific capillary change in 10.0% of the patients with lcSSc and only in 3.6% of the patients with dcSSc. Dilated capillaries without loss of capillaries were found in 42% of the patients with lcSSc and in 10.9% of the patients with dcSSc (p=0.05). However, severe capillary damage (loss of capillaries) was noticed more frequently in patients with dcSSc (dcSSc/lcSSc: 85.5%/48.0%, p=0.002). Pitting scars or digital ulcers were found in 46.0% of the patients with lcSSc and in 67.3% of the patients with dcSSc (p=0.04). We did not notice a significant difference in frequency of fingertip osteolysis and telangiectasia. Esophageal hypomotility was found in 64% of the patients with lcSSc and in 85.5% of the patients with dcSSc (p<0.01). We found interstitial lung fibrosis more frequently in patients with dcSSc (lcSSc/dcSSc: 16.0%/72.7%, p<0.001). Reduced forced vital capacity (FVC) was found in 6.0% of the of patients with lcSSc and in 41.8% of the patients with dcSSc (p<0.001). A decreased value of the transfer factor for carbon monoxide (DLCO) was also observed more frequently in patients with dcSSc. Heart involvement was found in 29.1% of the patients with dcSSc and less frequently (p<0.001) in patients with lcSSc (8%). Similarly, we found renal involvement more frequently in patients with dcSSc (lcSSc/dcSSc: 2.0%/16.3%). Tendon friction rubs were noticed in 23.6% of the patients with dcSSc and only in 6% of the patients with lcSSc (p<0.01). Joint contractures were observed in 70.9% of the patients with dcSSc and in 26.0% of the patients with lcSSc (p<0.001). Muscle weakness was noticed more frequently in patients with dcSSc (lcSSc/dcSSc: 22.0%/40.0%, p<0.05). Arthralgia was found more frequently in patients with dcSSc, but arthritis became apparent, without significant difference in frequency, in 16% of the patients with lcSSc and in 16.4% of the patients with dcSSc. Loss of capillaries (detected by nailfold capillaroscopy), digital ulcers, interstitial lung fibrosis, decreased FVC and DLCO, esophageal hypomotility, musculoskeletal impairment, and heart and renal involvement are more common in patients with dcSSc. Fingertip osteolysis, telangiectasia, and arthritis are equally frequent in both forms of the disease.

Autoantibodies in systemic sclerosis

OBJECTIVES

To describe the clinical, laboratory, and prognostic features associated with the scleroderma-specific autoantibodies.

METHODS

Using the Pittsburgh Scleroderma Databank, all consecutive patients seen between 1980 and 1995 who had autoantibody studies performed were studied. Anticentromere antibodies (ACA), antitopoisomerase (TOPO), anti-U1-RNP (U1-RNP), anti-RNA Polymerase III (Pol 3), anti-U3-RNP (U3-RNP), anti-Th/To (Th/To), and anti-Pm/Scl (Pm/Scl) were determined according to previously described methods. The frequency of clinical features, organ system outcomes, and survival within the patients with a specific antibody were cumulative over the course of the disease. The frequency of a specific feature was compared across groups to identify significant manifestations and outcomes in patients with a specific antibody.

RESULTS

Some demographic, clinical, and organ system findings were associated with the specific antibody, and other features with the scleroderma subtype (limited cutaneous or diffuse cutaneous scleroderma). U3-RNP, U1-RNP, and TOPO were seen more commonly in African-American patients, and ACA was seen in older, female Caucasians. Muscle inflammation was seen in patients with U1-RNP and U3-RNP. Digital tip ulcers and digital tuft resorption were seen more frequently in those with ACA and TOPO. A vasculopathy causing pulmonary hypertension typically occurs with ACA and pulmonary fibrosis with TOPO; however, both types of lung disease were seen in patients with nucleolar antibodies, Th/To and U3-RNP. Importantly, severe interstitial fibrosis was rarely seen in cases with Pol 3. Renal crisis was strongly associated with Pol 3. Survival within limited scleroderma was decreased in the Th/To patients compared with ACA patients. Within the diffuse scleroderma group, patients with Pol 3 had the best survival.

CONCLUSIONS

Scleroderma autoantibodies are associated with very specific demographic, clinical, organ system, and survival features.

RELEVANCE

The determination of scleroderma autoantibodies may be helpful in assessing the prognosis, monitoring, and treatment of scleroderma patients.

Occurrence of an activated, profibrotic pattern of gene expression in lung CD8+ T cells from scleroderma patients

OBJECTIVE

Pulmonary fibrosis is a major cause of death in scleroderma patients. Previous studies have shown an increase in CD8+ T cells in the lungs of scleroderma patients. In the present study, we sought to determine whether activated CD8+ T cells contribute to pulmonary fibrosis in scleroderma patients through the production and activation of profibrotic mediators.

METHODS

CD8+ cells were isolated from bronchoalveolar lavage fluid obtained from 19 scleroderma patients and 7 healthy subjects. The phenotype of these cells was determined using DNA array technology. Expression of selected genes was confirmed in real-time polymerase chain reaction and enzyme-linked immunosorbent assay experiments.

RESULTS

Hierarchical clustering of gene expression profiles revealed 2 groups of subjects. Group 1 consisted of 11 patients (8 with and 3 without lung inflammation). Group 2 consisted of 15 subjects (7 healthy controls and 2 patients with and 6 without lung inflammation). Gene expression in group 1 indicated T cell activation, a type 2 phenotype, production of profibrotic factors and matrix metalloproteinases, and reduced activation-induced cell death. Increased expression of beta6 integrin messenger RNA by CD8+ T cells in group 1 suggested the possibility that these T cells might induce cell-contact-dependent activation of latent transforming growth factor beta (TGFbeta).

CONCLUSION

A subset of scleroderma patients at higher risk of progressive lung disease have activated, long-lived CD8+ T cells in their lungs that could promote fibrosis directly, through production of profibrotic factors such as interleukin-4 and oncostatin M, as well as indirectly, through activation of TGFbeta.

Elevated exhalation of hydrogen peroxide in patients with systemic sclerosis

BACKGROUND

Systemic sclerosis is accompanied by an influx of activated phagocytes into distal airways. These cells release H2O2, which may evaporate from the airways surface and be detected in expired breath condensate. We tested whether patients with systemic sclerosis exhale more H2O2 than healthy subjects and whether breath condensate H2O2 levels correlate with some clinical parameters.

MATERIAL AND METHODS

H2O2 was measured fluorimetrically in the expired breath condensate of 27 patients (22 women, five men, mean age 49 +/- 13.1 years) with systemic sclerosis and 27 age- and sex- matched healthy controls.

RESULTS

Exhaled H2O2 levels were 3.5-fold higher (0.88 +/- 0.62 microM vs. 0.25 +/- 0.17 microM, P < 0.001) in the patients with systemic sclerosis than in the controls. Treatment with cyclophosphamide and/or prednisone (29 +/- 50 months, range 3-168 months) did not significantly decrease H2O2 exhalation (0.78 +/- 0.50 microM, n= 10 vs. 0.94 +/- 0.67 microM, n= 17, P > 0.05). No significant difference was found between patients with limited and diffuse scleroderma (1.03 +/- 0.69 microM, n= 17 vs. 0.63 +/- 0.41 microM, n= 10, P > 0.05). H2O2 levels correlated with disease duration (r = 0.38, P < 0.05) and time from the first Raynaud's episode (r = 0.44, P < 0.05).

CONCLUSIONS

Patients with systemic sclerosis exhale more H2O2 than healthy controls, suggesting involvement of reactive oxygen species in disease processes. Lack of significant intergroups differences in H2O2 levels may have resulted from the small number of patients analyzed.

The clinical relevance of autoantibodies in scleroderma

Scleroderma (systemic sclerosis) is associated with several autoantibodies, each of which is useful in the diagnosis of affected patients and in determining their prognosis. Anti-centromere antibodies (ACA) and anti-Scl-70 antibodies are very useful in distinguishing patients with systemic sclerosis (SSc) from healthy controls, from patients with other connective tissue disease, and from unaffected family members. Whereas ACA often predict a limited skin involvement and the absence of pulmonary involvement, the presence of anti-Scl-70 antibodies increases the risk for diffuse skin involvement and scleroderma lung disease. Anti-fibrillarin autoantibodies (which share significant serologic overlap with anti-U3-ribonucleoprotein antibodies) and anti-RNA-polymerase autoantibodies occur less frequently and are also predictive of diffuse skin involvement and systemic disease. Anti-Th/To and PM-Scl, in contrast, are associated with limited skin disease, but anti-Th/To might be a marker for the development of pulmonary hypertension. Other autoantibodies against extractable nuclear antigens have less specificity for SSc, including anti-Ro, which is a risk factor for sicca symptoms in patients with SSc, and anti-U1-ribonucleoprotein, which in high titer is seen in patients with SSc/systemic lupus erythematosus/polymyositis overlap syndromes. Limited reports of other autoantibodies (anti-Ku, antiphospholipid) have not established them as being clinically useful in following patients with SSc.

Anti-topoisomerase II alpha autoantibodies in systemic sclerosis-association with pulmonary hypertension and HLA-B35

We have previously detected autoantibodies against topoisomerase II alpha (anti-topo II alpha) in sera from patients with idiopathic pulmonary fibrosis. To determine whether anti-topo II alpha is also present in systemic sclerosis (SSc) patients with pulmonary involvement, we screened sera from 92 patients and 34 healthy controls. Presence of anti-topo II alpha was investigated with respect to clinical and serological features, including the frequencies of HLA class I and II alleles. Anti-topo II alpha was detected in 20/92 (21.7%) patients. No association was found with either anti-topoisomerase I (Scl-70 or anti-topo I) or anti-centromere antibodies. However, anti-topo II alpha was associated with the presence of pulmonary hypertension (PHT) (as opposed to pulmonary fibrosis), and with a decrease of carbon monoxide diffusing capacity. Anti-topo II alpha was strongly associated with the presence of the class I antigen HLA-B35. No significant association was found with HLA class II antigens. HLA-B35 also turned out to be associated with the presence of PHT. These results indicate that in SSc patients, the presence of anti-topo II alpha is associated with PHT, and that the simultaneous presence of HLA-B35 seems to add to the risk of developing PHT.

[Pulmonary involvement in systemic scleroderma. Part I. Chronic fibrosing interstitial lung disease]

INTRODUCTION

Chronic pulmonary interstitial fibrosis is the most frequent respiratory manifestation in systemic sclerosis, occurring in 80% of cases. It remains a severe complication of the disease and is the primary cause of mortality related to respiratory insufficiency in 20 to 60% of cases.

CURRENT KNOWLEDGE AND KEY POINTS

The date of onset of interstitial lung disease remains undetermined, and only in rare cases does it reveal the presence of systemic sclerosis. The clinical signs are only observable at a later stage, when at least 50% of the lung parenchyma is affected. The methods of choice adopted for early diagnosis of this disease are high resolution computed tomography and pulmonary functional investigations; they should be carried out during the preliminary investigation and at follow-up once a year. Moreover, high resolution computed tomography also provides prognostic data, for there is a correlation between the type of lesion and its severity as determined by high resolution computed tomography and by histological findings. The value of other methods of investigation, in particular bronchoalveolar lavage, has not yet been clearly established. The association of cyclophosphamide and corticoids is currently being evaluated (indications, administration modalities, duration), and this combination may be the most effective treatment.

FUTURE PROSPECTS AND PROJECTS

Interstitial lung disease is one of the major causes of morbidity and mortality in systemic sclerosis. Early diagnosis and management of this disease is therefore of utmost importance.

Manifestations of scleroderma pulmonary disease

Scleroderma is a multisystem disease of unknown cause characterized by synthesis and deposition of excessive extracellular matrix and vascular anti-GBM antibodies, leading to pulmonary hemorrhage and glomerulonephritis with rapidly progressive renal insufficiency. Recent advances in the understanding of disease pathogenesis and diagnosis and treatment have significantly improved our ability to recognize the syndrome, distinguish it from other similar disorders, and offer successful treatment. This article focuses on the pathogenetic features, clinical manifestations, diagnostic strategies, and therapeutic principles of anti-GBM disease.

Interstitial lung disease in systemic sclerosis: comparison of BALF lymphocyte phenotype and DLCO impairment

Patients with scleroderma (systemic sclerosis-SSc) frequently develop an interstitial lung disease. The role of lymphocytes in fibrosing alveolitis preceding lung fibrosis has been established. The purpose of this work was to evaluate cell profiles and lymphocyte phenotypes in the bronchoalveolar lavage (BAL) fluid and to correlate them with depression in lung function tests detected by depletion of diffusing capacity (DLCO). BAL was carried out in 25 untreated, non-smoking patients suffering from diffuse scleroderma and in 12 healthy non-smoking volunteers. For the analysis of lymphocyte sub-sets flow cytometry and monoclonal antibodies were used. The following cell sub-types were counted: T lymphocytes, B lymphocytes, helper lymphocytes, suppressor/cytotoxic lymphocytes, natural killer cells, cytotoxic T lymphocytes and activated T lymphocytes. The total cell count was higher in the group of patients with mild and moderate impairment in DLCO. The percentage of lymphocytes was greater in patients with DLCO lower than 65% of the predicted value since neutrophilia was found in patients with severe DLCO depletion, i.e. significant when compared with healthy subjects. The proportions of suppressor/cytotoxic lymphocytes and of activated T lymphocytes were higher in patients than in controls. The statistical analysis revealed significant differences between patients with moderate and mild changes in DLCO and the healthy volunteers. A decreased helper/suppressor ratio was noticed in these patients. We concluded that the BALF lymphocyte phenotype analysis may reflect the features of alveolitis in patients with SSc.

Abnormal uptake of Tc-99m MIBI, a novel myocardial imaging agent, in the lungs of patients with systemic sclerosis

OBJECTIVE

Fibrosing alveolitis is a prominent feature of systemic sclerosis (SSc), and accounts for much of the morbidity and mortality of this disease. Sensitive techniques for the detection and monitoring of fibrosing alveolitis could target patients for early therapeutic intervention. The objective of this small pilot study was to assess the frequency and clinical significance of abnormal lung uptake of Tc-99m MIBI, a novel radionuclide imaging agent that selectively accumulates in cells rich in mitochondria.

METHODS

Sixteen patients with SSc and evidence of pulmonary involvement were studied. The uptake of radionuclide in the lungs, and the ratio of pulmonary to cardiac uptake were evaluated after intravenous injection of Tc-99m MIBI. Results were correlated with clinical and laboratory parameters.

RESULTS

Lung uptake of Tc-99m MIBI was increased in all 16 SSc patients compared to control patients with coronary heart disease but no evidence of pulmonary abnormality. The degree of isotope uptake in the lungs was correlated with the extent of maximal skin induration and with radiologic evidence of interstitial lung disease, but not with other clinical or laboratory parameters of disease activity or extent of pulmonary involvement. The ratio of pulmonary to cardiac uptake of isotope was also increased in patients with SSc compared to controls.

CONCLUSION

Accumulation of Tc-99m MIBI is abnormally elevated in the lungs of SSc patients with pulmonary involvement. Isotope accumulation in the lungs may be related to activation of fibroblasts or endothelial cells. The specificity and sensitivity of Tc-99m MIBI scanning in the detection and monitoring of pulmonary involvement, and its potential role in the management of SSc, deserve further investigation.