Comparative qualitative and quantitative analysis of scleroderma (systemic sclerosis) serologic immunoassays

The Frequency of Scleroderma Renal Crisis over Time: A Metaanalysis

Objective.

Systemic sclerosis (SSc) leads to a high mortality from internal organ involvement. Scleroderma renal crisis (SRC) usually occurs in the diffuse cutaneous SSc (dcSSc) subset early in the disease, often with acute severe hypertension and renal failure. Prevalence of SRC since its classification in the early 1970s was determined in publications to assess whether the prevalence of SRC has changed over time because the proportion with the dcSSc subset is smaller in contemporary cohorts.

Methods.

A review of the literature was conducted up to May 2015 using the PubMed, EMBASE, CINAHL, and Cochrane Library databases. Articles were included if they mentioned the prevalence of SRC and were cohort or cross-sectional studies with 50 or more patients with SSc. Articles were excluded if they were not in English or were a case series of SRC or case-control studies.

Results.

Of the 5317 citations identified, 22 qualified. Years of publication were from 1983 to 2011, and cohort size varied from 68 to 8554 patients with SSc totaling 21,908 patients (9248 with dcSSc, 42%). There was no statistical reduction in the temporal prevalence of SRC noticed in the overall patients (4%), patients with dcSSc (7%–9%), or patients with limited cutaneous SSc (lcSSc; 0.5%–0.6%) based on either the start date of the cohort or publication date.

Conclusion.

It appears that SRC remains uncommon in lcSSc and the rate in the dcSSc group may be stable over time. However, increasing awareness of SRC could lead to higher rates in more recent years and/or better survival from SRC, but this was not observed.

The 15% rule in scleroderma: the frequency of severe organ complications in systemic sclerosis. A systematic review

OBJECTIVE

The prevalence of organ complications in scleroderma (systemic sclerosis; SSc) varies by definition used. This study was done to determine the frequency of several features of SSc.

METHODS

A search of Medline-Ovid/Embase, PubMed, and Scopus databases from 1980 to November 30, 2011, was conducted to identify relevant articles with at least 50 patients with SSc extracting prevalence of each organ complication. Study quality was assessed using the STROBE (Strengthening The Reporting of OBservational studies in Epidemiology) checklist. Pooled prevalence was calculated using the random effects method. Heterogeneity was quantified using I(2).

RESULTS

A total of 5916 articles were identified (913 from Medline-Ovid/Embase, 1009 from PubMed, and 3994 from Scopus); 5665 were excluded, leaving 251 articles for full-text review, with 69 included. Where available, frequencies were also included from the Canadian Scleroderma Research Group. Many severe complications in SSc occur about 15% of the time, including cardiac involvement (15%, 95% CI 6-24), diastolic dysfunction (16%, 95% CI 14-17), estimated pulmonary artery pressure > 40 mm Hg (18%, 95% CI 14-21), pulmonary arterial hypertension by right heart catheterization (15%, 95% CI 12-17), forced vital capacity (FVC) < 70% predicted (15%, 95% CI 12-17), FVC < 80% predicted (17%, 95% CI 12-21), myositis (13%, 95% CI 10-17), inflammatory arthritis (12%, 95% CI 9-16), Sjögren overlap (13%, 95% CI 10-16), and digital ulcers (DU; 15%, 95% CI 10-20); and 15% of DU have complications (amputations 12%, 95% CI 8-16, and hospitalizations 13%, 95% CI 6-21). Scleroderma renal crisis is uncommon but occurs in almost 15% (12%, 95% CI 5-19) of cases of disseminated cutaneous SSc. There is no 15% rule within skin and gastrointestinal tract for SSc.

CONCLUSION

The "15%" rule for frequency of significant organ involvement in SSc is helpful.

Frequency of disease-associated and other nuclear autoantibodies in patients of the German Network for Systemic Scleroderma: correlation with characteristic clinical features

Introduction

In the present study, we analysed in detail nuclear autoantibodies and their associations in systemic sclerosis (SSc) patients included in the German Network for Systemic Scleroderma Registry.

Methods

Sera of 863 patients were analysed according to a standardised protocol including immunofluorescence, immunoprecipitation, line immunoassay and immunodiffusion.

Results

Antinuclear antibodies (ANA) were detected in 94.2% of patients. In 81.6%, at least one of the autoantibodies highly associated with SSc or with overlap syndromes with scleroderma features was detected, that is, anti-centromere (35.9%) or anti-topoisomerase I (30.1%), followed in markedly lower frequency by antibodies to PM-Scl (4.9%), U1-ribonucleoprotein (U1-RNP) (4.8%), RNA polymerases (RNAPs) (3.8%), fibrillarin (1.4%), Ku (1.2%), aminoacyl-transfer RNA synthetases (0.5%), To (0.2%) and U11-RNP (0.1%). We found that the simultaneous presence of SSc-associated autoantibodies was rare (1.6%). Furthermore, additional autoantibodies were detected in 55.4% of the patients with SSc, of which anti-Ro/anti-La, anti-mitochondrial and anti-p25/p23 antibodies were most frequent. The coexistence of SSc-associated and other autoantibodies was common (43% of patients). SSc-associated autoantibodies disclosed characteristic associations with clinical features of patients, some of which were previously not acknowledged.

Conclusions

This study shows that five autoantigens (that is, centromere, topoisomerase I, PM-Scl, U1-RNP and RNAP) detected more than 95% of the known SSc-associated antibody responses in ANA-positive SSc patients and characterise around 79% of all SSc patients in a central European cohort. These data confirm and extend previous data underlining the central role of the determination of ANAs in defining the diagnosis, subset allocation and prognosis of SSc patients.

Experimental evidence on the immunopathogenesis of primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is a chronic cholestatic liver disease for which an autoimmune pathogenesis is supported by clinical and experimental data, including the presence of autoantibodies and autoreactive T cells. The etiology remains to be determined, yet data suggest that both a susceptible genetic background and unknown environmental factors determine disease onset. Multiple infectious and chemical candidates have been proposed to trigger the disease in a genetically susceptible host, mostly by molecular mimicry. Most recently, several murine models have been reported, including genetically determined models as well as models induced by immunization with xenobiotics and bacteria.