Assessment of damage and activity in systemic sclerosis

The challenges and controversies of measuring disease activity in systemic sclerosis

Major alteration of the natural history of systemic sclerosis is limited with current treatments, and the development of novel therapies has been hampered, in part, by the lack of fully validated multi-system outcome measures. There remains a lack of consensus as to the very definition of systemic sclerosis disease activity, complicating efforts to measure activity in clinical trials. Previously published multi-system measures of disease status are yet to be fully validated according to the Outcome Measures in Rheumatology (OMERACT) filter. There is currently significant research interest in developing new systemic sclerosis-specific measures to better describe and compare patient cohorts and measure therapeutic responses in clinical trials. An accurate measure of disease activity in systemic sclerosis will facilitate the enrichment of clinical trials with patients who have active disease, targeting a group of patients most likely to benefit from therapeutic intervention. In addition, following on from successes in other rheumatic conditions, a state of low disease activity, measured by an activity index, may become a clinical trial end point and therapeutic target. The Scleroderma Clinical Trials Consortium has undertaken to develop a definition of disease activity and fully validate a new systemic sclerosis activity index. The Scleroderma Clinical Trials Consortium Activity Index will be developed using consensus and data-driven methods and is envisaged to be widely used in research and clinical settings.

Summed and Weighted Summary Scores for the Medsger Disease Severity Scale Compared with the Physician’s Global Assessment of Disease Severity in Systemic Sclerosis

Objective.

To develop a weighted summary score for the Medsger Disease Severity Scale (DSS) and to compare its measurement properties with those of a summed DSS score and a physician’s global assessment (PGA) of severity score in systemic sclerosis (SSc).

Methods.

Data from 875 patients with SSc enrolled in a multisite observational research cohort were extracted from a central database. Item response theory was used to estimate weights for the DSS weighted score. Intraclass correlation coefficients (ICC) and convergent, discriminative, and predictive validity of the 3 summary measures in relation to patient-reported outcomes (PRO) and mortality were compared.

Results.

Mean PGA was 2.69 (SD 2.16, range 0–10), mean DSS summed score was 8.60 (SD 4.02, range 0–36), and mean DSS weighted score was 8.11 (SD 4.05, range 0–36). ICC were similar for all 3 measures [PGA 6.9%, 95% credible intervals (CrI) 2.1–16.2; DSS summed score 2.5%, 95% CrI 0.4–6.7; DSS weighted score 2.0%, 95% CrI 0.1–5.6]. Convergent and discriminative validity of the 3 measures for PRO were largely similar. In Cox proportional hazards models adjusting for age and sex, the 3 measures had similar predictive ability for mortality (adjusted R2 13.9% for PGA, 12.3% for DSS summed score, and 10.7% DSS weighted score).

Conclusion.

The 3 summary scores appear valid and perform similarly. However, there were some concerns with the weights computed for individual DSS scales, with unexpected low weights attributed to lung, heart, and kidney, leading the PGA to be the preferred measure at this time. Further work refining the DSS could improve the measurement properties of the DSS summary scores.

Relationship between disease characteristics and orofacial manifestations in systemic sclerosis: Canadian Systemic Sclerosis Oral Health Study III

OBJECTIVE

Systemic sclerosis (SSc; scleroderma) is associated with decreased saliva production and interincisal distance, more missing teeth, and periodontal disease. We undertook this study to determine the clinical correlates of SSc with these oral abnormalities.

METHODS

Subjects were recruited from the Canadian Scleroderma Research Group cohort. Detailed dental and clinical examinations were performed according to standardized protocols. Associations between dental abnormalities and selected clinical and serologic manifestations of SSc were examined.

RESULTS

One hundred sixty-three SSc subjects were included: 90% women, mean ± SD age 56 ± 11 years, mean ± SD disease duration 14 ± 8 years, 72% with limited cutaneous disease, and 28% with diffuse cutaneous disease. Decreased saliva production was associated with Sjögren's syndrome-related autoantibodies (β = -43.32; 95% confidence interval [95% CI] -80.89, -5.75), but not with disease severity (β = -2.51; 95% CI -8.75, 3.73). Decreased interincisal distance was related to disease severity (β = -1.02; 95% CI -1.63, -0.42) and the modified Rodnan skin thickness score (β = -0.38; 95% CI -0.53, -0.23). The number of missing teeth was associated with decreased saliva production (relative risk [RR] 0.97; 95% CI 0.94, 0.99), worse hand function (RR 1.52; 95% CI 1.13, 2.02), and the presence of gastroesophageal reflux disease (GERD; RR 1.68 [95% CI 1.14, 2.46]). No clinical or serologic variables were correlated with periodontal disease.

CONCLUSION

In SSc, diminished interincisal distance is related to overall disease severity. Decreased saliva production is related to concomitant Sjögren's syndrome antibodies. Tooth loss is associated with poor upper extremity function, GERD, and decreased saliva. The etiology of excess periodontal disease is likely multifactorial and remains unclear.

Nutritional status and gastrointestinal symptoms in systemic sclerosis patients

BACKGROUND AND AIMS

Gastrointestinal manifestations in systemic sclerosis (SSc) can influence the nutritional status of patients. Our objective was to examine whether nutritional status was associated with symptoms captured by the University of California Los Angeles Scleroderma Clinical Trials Consortium Gastrointestinal Tract Questionnaire (GIT 2.0).

METHODS

A series of 24 University of Utah SSc Center patients were assessed using the MUST, SGA, and GIT 2.0. A single evaluator administered the nutrition assessment and gastrointestinal symptom questionnaire.

RESULTS

Nine patients were assessed at moderate to high risk of malnutrition using the Malnutrition Universal Screening Tool (MUST) and 12 patients with moderate to severe malnutrition using Subjective Global Assessment (SGA). Neither MUST nor SGA status was associated with duration of disease. Soilage, social function and emotional subscores were associated with SGA nutritional status. Clinically significant differences in Total GIT 2.0 score, reflux, distention/bloating, soilage, diarrhea, social function and emotional well-being were observed across levels of nutritional status.

CONCLUSIONS

Clinically significant differences in gastrointestinal tract symptoms were observed across levels of nutritional status in patients with varying severity of SSc. These two clinically utilized tools, the SGA and the GIT 2.0, appear to be complementary in the evaluation of SSc patients.

Discordance between Patient and Physician Assessments of Disease Severity in Systemic Sclerosis

Objective.

To describe the magnitude and correlates of discordance between patient and physician assessments of disease severity in patients with systemic sclerosis (SSc).

Methods.

Subjects were patients enrolled in the Canadian Scleroderma Research Group Registry. The outcomes of interest were patient and physician global assessments of disease severity (scales ranging from 0–10). Predictors of disease severity represented the spectrum of disease in SSc (skin involvement, severity of Raynaud’s phenomenon, shortness of breath, gastrointestinal symptoms and pain, number of fingertip ulcers, tender and swollen joints, creatinine, and fatigue). The results of the analysis were validated in an independent sample of patients with SSc from the United States.

Results.

Patients perceived greater disease severity than physicians (mean difference 0.78 ± 2.65). The agreement between patient and physician assessments of disease severity was, at best, modest (intraclass correlation 0.3774; weighted κ 0.3771). Although both patients and physicians were influenced by skin scores, breathlessness, and pain, the relative importance of these predictors differed. Patients were also influenced by other subjective symptoms, while physicians were also influenced by disease duration and creatinine. The predictors explained 56% of the deviance in the patient global assessments and 29% in the physician assessments. These findings were confirmed in the US dataset.

Conclusion.

Patients and physicians rate SSc disease severity differently in magnitude and are influenced by different factors. Patient-assessed and physician-assessed measures of severity should be considered as complementary and used together in future studies of SSc.

The Association Between Disease Activity and Duration in Systemic Sclerosis

Objective.

The absence of a standardized disease activity index has been an important barrier in systemic sclerosis (SSc) research. We applied the newly derived Valentini Scleroderma Disease Activity Index (SDAI) among our cohort of patients with SSc to document changes in disease activity over time and to assess possible differences in activity between limited and diffuse disease.

Methods.

Cross-sectional study of a national cohort of patients enrolled in the Canadian Scleroderma Research Group Registry. Disease activity was measured using the SDAI. Depression scores were measured using the Centre for Epidemiologic Studies Depression Scale (CES-D).

Results.

A total of 326 out of 639 patients had complete datasets at the time of this analysis; 87% were female, of mean age 55.6 years, with mean disease duration 14.1 years. SDAI declined steeply in the first 5 years after disease onset and patients with diffuse disease had 42% higher SDAI scores than patients with limited disease with the same disease duration and depression scores (standardized relative risk 1.42, 95% CI 1.21, 1.65). Patients with higher CES-D scores had higher SDAI scores relative to patients with the same disease duration and disease subset (standardized RR 1.22, 95% CI 1.14, 1.31). Among the 10 components that make up the SDAI, only skin score (standardized OR 0.59, 95% CI 0.43, 0.82) and patient-reported change in skin (standardized OR 0.64, 95% CI 0.45, 0.92) decreased with increasing disease duration. High skin scores (standardized OR 32.2, 95% CI 15.8, 72.0) were more likely and scleredema (standardized OR 0.58, 95% CI 0.37, 0.92) was less likely to be present in patients with diffuse disease. High depression scores were associated with positive responses for patient-reported changes in skin and cardiopulmonary function.

Conclusion.

Disease activity declined with time and patients with diffuse disease had consistently higher SDAI scores. Depression was found to be associated with higher patient activity scores and strongly associated with patient self-response questions. The role of depression should be carefully considered in future applications of the SDAI, particularly as several components of the score rely upon patient recall.

Targeting TNF for Treatment of Cancer and Autoimmunity

Tumor necrosis factor-alpha (TNF-alpha) was first isolated two decades ago as a macrophageproduced protein that can effectively kill tumor cells. TNF-alpha is also an essential component of the immune system and is required for hematopoiesis, for protection from bacterial infection and for immune cell-mediated cytotoxicity. Extensive research, however, has revealed that TNF-alpha is one of the major players in tumor initiation, proliferation, invasion, angiogenesis and metastasis. The proinflammatory activities link TNF-alpha with a wide variety of autoimmune diseases, including psoriasis, inflammatory bowel disease, rheumatoid arthritis, systemic sclerosis, systemic lupus erythematosus, multiple sclerosis, diabetes and ankylosing spondylitis. Systemic inhibitors of TNF such as etanercept (Enbrel) (a soluble TNF receptor) and infliximab (Remicade) and adalimumab (Humira) (anti-TNF antibodies) have been approved for the treatment inflammatory bowel disease, psoriasis and rheumatoid arthritis. These drugs, however, exhibit severe side effects and are expensive. Hence orally active blockers of TNF-alpha that are safe, efficacious and inexpensive are urgently needed. Numerous products from fruits, vegetable and traditional medicinal plants have been described which can suppress TNF expression and TNF signaling but their clinical potential is yet uncertain.

Malnutrition is common in systemic sclerosis: results from the Canadian scleroderma research group database

OBJECTIVE

Systemic sclerosis (SSc) is a multisystem disease associated with significant morbidity and increased mortality. Little is known about nutritional status in SSc. We investigated the prevalence and demographic and clinical correlates of nutritional status in a large cohort of patients with SSc.

METHODS

This was a cross-sectional multicenter study of patients (n = 586) from the Canadian Scleroderma Research Group Registry. Patients were assessed with detailed clinical histories, medical examinations, and self-administered questionnaires. The primary outcome was risk for malnutrition using the "malnutrition universal screening tool" (MUST). Multiple logistic regression was used to assess the relationship between selected demographic and clinical variables and MUST categories.

RESULTS

Of the 586 patients in the study, MUST scores revealed that almost 18% were at high risk for malnutrition. The significant correlates of high malnutrition risk included the number of gastrointestinal (GI) complaints, disease duration, diffuse disease, physician global assessment of disease severity, hemoglobin, oral aperture, abdominal distension on physical examination, and physician-assessed possible malabsorption. Among 14 GI symptoms, only poor appetite and lack of a history of abdominal swelling and bloating predict MUST. These factors accounted for 24% of the variance in MUST scores.

CONCLUSION

The risk for malnutrition in SSc is moderate and is associated with shorter disease duration, markers of GI involvement, and disease severity. Patients with SSc should be screened for malnutrition, and potential underlying causes assessed and treated when possible.

Update on Indices of Disease Activity in Systemic Sclerosis

OBJECTIVE

An important barrier in the study of systemic sclerosis (SSc) is the difficulty in measuring disease activity. We reviewed the literature on currently available global measures of disease activity in SSc.

METHODS

The PubMed database (1950-2006) was searched for the key words "scleroderma" in conjunction with "disease activity" and then "disease severity." All relevant original and review articles in English and French were reviewed. Textbooks in rheumatology and pertinent secondary references were also reviewed.

RESULTS

There are currently 3 tools that are used to measure disease activity globally in SSc. Physician global assessments have been commonly used but have not been formally evaluated. The Valentini Disease Activity Index is a new measure that consists of 10 variables and a resulting score ranging from 0 to 10. It appears easy to use but lacks some face and content validity and responsiveness to change has yet to be demonstrated. The Medsger Disease Severity Scale measures disease severity in 9 organ systems. However, it assesses mostly damage and is difficult to score.

CONCLUSIONS

There is currently no gold standard measure of disease activity in SSc. Given the need to measure disease activity in SSc and the limitations of the currently available instruments, efforts are ongoing to develop new ones. This represents a major challenge but one that remains particularly important to undertake.

Microvascular damage in systemic sclerosis: Detection and monitoring with biomarkers

Vascular disease is universal in patients with systemic sclerosis (SSc), but there is a wide variability in its severity. It is clear that there is an early insult to the microvasculature, followed-up by on-going chronic process. This results in profound vascular damage in a subset of patients who develop severe events such as digital loss and pulmonary arterial hypertension. Although there is abundant evidence of vascular perturbation from studies of peripheral blood in SSc, there are few data about the ability to use these biomarkers to predict vascular outcomes. This paper examines the possibility of using circulating biomarkers to assess vascular disease activity and to predict severe vascular events among patients with SSc.

Alpha4beta1 and alpha4beta7 CD4 T cell numbers increase and CLA CD4 T cell numbers decrease in systemic sclerosis

We studied the expression of adhesion molecules affecting recirculation and homing on peripheral blood CD4(+) T cells of patients with systemic sclerosis (SSc), in order to evaluate whether the distribution of tissue targeted subsets could reflect the participation of internal organs or the extent of cutaneous involvement [i.e. limited cutaneous (lc) and diffuse cutaneous (dc)]. Peripheral blood mononuclear cells (PBMC) from 51 patients with SSc and 19 sex- and age-matched controls were investigated by cytofluorimetric analysis for lymphocyte subpopulations carrying the following surface molecules: CD3, CD4, CLA, alpha4beta7 and alpha4beta1. Standard routine biochemistry and clinical examinations were also performed in all patients. We found that both alpha4beta1(+) and alpha4beta7(+) cells within the CD4(+) T cell population were significantly increased, while CLA(+) CD4(+) T cells were significantly reduced in SSc, compared to healthy donors. Significantly lower absolute numbers of alpha4beta7(+) cells were found in lc- compared to dc-SSc. Patients with oesophageal involvement had high numbers of alpha4beta7(+) cells, while those with nephritis also showed low levels of CLA(+) cells. Lung involvement was related directly to alpha4beta1(+) cell numbers and inversely to alpha4beta7(+) CD4 cell numbers. Taken together, our findings demonstrate that distinct CD4(+) T cell populations with selective homing properties show changes from normal distribution in SSc, and such changes are related to clinical expression and organ involvement in the course of the disease.

Cytokine and chemokine levels in systemic sclerosis: relationship with cutaneous and internal organ involvement

Systemic sclerosis (SSc) is a connective tissue disorder characterized by excessive collagen deposition in the skin and internal organs. Several cytokines and chemokines have been implicated in the induction of fibrosis, but a definitive relationship between specific cytokines and organ involvement has not been established yet. Serum samples, PBMC and T cell lines (TCL) obtained from 54 patients affected by SSc and 20 healthy donors (HD) were examined by ELISA for Interferon-gamma (IFN-gamma ), interleukin (IL)-4, IL-6, IL-10, IL-18, Transforming growth factor (TGF)-beta1, Tumour necrosis factor (TNF)-alpha, sCD30, Macrophage derived chemokine (MDC), Monocyte chemoattractant protein (MCP)-1, Macrophage inflammatory protein (MIP)-1alpha and Regulated on activation normal T-cell expressed and secreted (RANTES). In all the SSc serum samples, we found significantly increased levels of IL6, TNFalpha and MCP-1 but reduced amounts of gamma-IFN and MDC. IL6, IL10, IL18, MIP-1alpha and TNFalpha measured in supernatants from PHA-stimulated PBMC and IL6, MCP-1 and RANTES in supernatants from stimulated TCL were also increased in patients. MDC was decreased in all the biological SSc sources studied. TGF-beta1, IL10, and sCD30 were produced at a significantly lower level by SSc TCL. Serum IL6 and sCD30 levels were significantly increased in dc-SSc patients compared to lc-SSc as were levels of MCP-1 produced by PBMC and IL10 from TCL. We observed a strict relationship between pulmonary fibrosis and IL10, MCP-1 (both from TCL) and serum IL6. Kidney involvement was related to serum MCP-1 levels and IL18 production from PBMC. Oesophageal involvement correlated with MDC production from PBMC and IL10 synthesis by TCL. We showed that IL-6, IL-10, MDC and MCP-1 are variably associated with internal organ involvement and allow the discrimination between limited and diffuse forms of the disease.

The assessment of the patient with systemic sclerosis

Systemic sclerosis presents a great deal of variability among different patients in the extent of skin and internal organ involvement, the pace of the disease and consequently, the prognosis. In addition, the single patient, during his/her disease course, can present with distinct manifestations. Each patient must, therefore, be carefully investigated. The assessment should be adapted to the setting, i.e. clinical practice, clinical investigation, therapeutic trials. The clinician cannot confine the diagnostic process to labelling the disease. He must define the subset, the extent of internal organ involvement, and the type of lesions underlying the clinical manifestations, i.e. fibrotic lesions, reflecting irreversible damage should be separated from active lesions (such as alveolitis) which can be reversed by drug treatment. The clinical investigator must assure that his/her patients are comparable to other series. ACR criteria have been shown to not assure such comparability. To this purpose, a core set of variables to be assessed in any clinical investigation study has been proposed. Finally, the clinical researcher should enrol patients with active disease and must rely for his/her conclusions on feasible and sensitive to change measures. An OMERACT committee has recently reviewed the literature selecting those ready for use in clinical trials.

Correlation of serum anti-DNA topoisomerase I antibody levels with disease severity and activity in systemic sclerosis

OBJECTIVE

To investigate correlations between serum levels of topoisomerase I-specific antibody (anti-topo I) and clinical features of systemic sclerosis (SSc), including disease severity (the total skin score [TSS]) and disease activity.

METHODS

Using highly sensitive enzyme-linked immunosorbent assays, we measured the levels of anti-topo I antibody, including total IgG, individual IgG subclasses, and IgA, and analyzed their correlations with the TSS in 59 patients with SSc, all of whom had diffuse cutaneous involvement. Serial serum samples were obtained from 11 of these patients.

RESULTS

The titers of anti-topo I antibody, including IgG and IgA, were positively correlated with the TSS, a measure of SSc disease severity. In 8 of the 11 patients from whom serial serum samples were obtained, changes in the levels of both IgG and IgA, when detectable, paralleled changes in the TSS. In 3 patients, an increasing anti-topo I IgG level preceded an increase in the TSS. The level of each IgG subclass also correlated with and tended to parallel the TSS. The patients with very active disease had higher mean IgG (P < 0.001) and IgA (P < 0.05) titers than did those with inactive disease.

CONCLUSION

Serum levels of anti-topo I antibody correlate positively with disease severity and disease activity in SSc.

Assessment of intestinal permeability and orocecal transit time in patients with systemic sclerosis: analysis of relationships with epidemiologic and clinical parameters

OBJECTIVE

The aim of this study was to assess intestinal permeability (IP) in patients with systemic sclerosis (SSc) and to relate the results with general disease activity and gastrointestinal involvement.

METHODS

Twenty-eight females and four males were studied. Patients with severe gastrointestinal involvement were excluded. Thirty-three healthy volunteers served as controls. Intestinal permeability was assessed by means of the orally administered cellobiose/mannitol sugar (Ce/Ma) test. Intestinal transit time (ITT) was investigated with the H2-lactulose breath test.

RESULTS

The mean value of IP in 32 SSc patients was significantly higher than in 33 controls ( P<0.05), although it fell within the normal range. Eleven patients showed abnormally high individual IP values (>0.028) that significantly correlated to disease duration ( r=0.73). Altered IP was associated with the higher but not statistically relevant presence of anti-Scl70 antibodies (9/11) and to more severe gastrointestinal involvement. More than half of the SSc patients showed slower orocecal transit times on the H2 breath test. In particular, delayed ITT was observed in 60% of patients with increased IP and in all patients with moderate gastrointestinal involvement according to the scleroderma severity scale.

CONCLUSION

Intestinal permeability was altered in 11/32 SSc patients. Correlations between increased IP and duration of disease and degree of gastrointestinal involvement appear to support the hypothesis of secondary involvement of the intestinal barrier, and the presence of anti-Scl70 antibodies in 82% of the patients with higher IP clearly reinforces the hypothesis of an altered immune response in these subjects.

Treating systemic sclerosis in 2001

Systemic sclerosis (SS) is characterized by sclerosis of the dermis and internal organs and by vascular abnormalities. Although the pathophysiology of the disease has been partly elucidated, the efficacy of long-term treatments remains limited, with no significant increase in survival in prospective studies. Conventional drug treatments are disappointing in clinical practice, and in a recent prospective randomized study standard-dose D-penicillamine was not more effective than mini-dose D-penicillamine. New long-term treatments are emerging for diffuse SS, including cyclophosphamide for patients with progressive interstitial lung disease or stem cell transplantation for those with early organ involvement. The most effective treatments remain symptomatic, such as angiotensin-converting enzyme inhibitors for acute renal crisis, calcium channel antagonists for Raynaud's phenomenon, and proton pump inhibitors for the complications of gastroesophageal reflux. This review article focuses on long-term treatments that are most likely to be effective and suggests symptomatic treatment strategies tailored to specific organ involvements.