Geographical heterogeneity of clinical and serological phenotypes of systemic sclerosis observed at tertiary referral centres. The experience of the Italian SIR-SPRING registry and review of the world literature

Systemic Sclerosis Sine Scleroderma: A Time of Reappraisal

OBJECTIVE

Systemic sclerosis sine scleroderma (ssSSc), formally described in 1962, is a subset of SSc that, unlike limited cutaneous (lcSSc) and diffuse cutaneous (dcSSc) forms, lacks skin fibrosis. According to the 2013 American College of Rheumatology/European Alliance of Associations for Rheumatology criteria, SSc can be diagnosed in the absence of skin thickening, even if this is expected to develop later in disease course. Driven by a fatal case of ssSSc with cardiac involvement, we analyzed published data on ssSSc prevalence and severity.

METHODS

A systematic literature review and qualitative synthesis of SSc cohorts with data on ssSSc were performed.

RESULTS

Thirty-five studies involving a total of 25,455 patients with SSc, published between 1976 and 2023, were identified. Although different definitions were used, the mean prevalence of ssSSc was almost 10% (range 0-23%), with the largest study reporting a cross-sectional prevalence of 13%. In 5 studies with a follow-up period of up to 9 years, reclassification of ssSSc into lcSSc or dcSSc ranged 0-28%. Interstitial lung disease, pulmonary arterial hypertension, scleroderma renal crisis, and cardiac diastolic dysfunction were present in 46% (range 9.3-59.1%), 15% (range 5.9-24.6%), 5% (range 1.6-24.6%), and 26.5% (range 1.8-40.7), respectively, of patients with ssSSc. Survival across studies was comparable to lcSSc and better than dcSSc.

CONCLUSION

Published data on ssSSc vary widely on prevalence, clinical expression, and prognosis, partly due to underdiagnosis and misclassification. Although classification criteria should not affect appropriate management of patients, updated ssSSc subclassification criteria that takes into account time from disease onset should be considered.

Practice pattern for the use of intravenous iloprost for the treatment of peripheral vasculopathy in systemic sclerosis: A case-control study from the Italian national multicenter "SPRING" (Systemic Sclerosis Progression InvestiGation) Registry

Background

Intravenous iloprost has been widely used for the treatment of systemic sclerosis peripheral vasculopathy. No agreement has been found on the regimen and the dosage of intravenous iloprost in different scleroderma subset conditions. This study aimed to evaluate the modalities of intravenous iloprost administration within a large cohort of systemic sclerosis patients from the SPRING Registry and to identify any associated clinical-demographic, instrumental or therapeutic data.

Patients and Methods

Data of systemic sclerosis patients treated with intravenous iloprost for at least 1 year (case group) were retrospectively analyzed, including different timing and duration of intravenous iloprost session, and compared with those of untreated patients (control group).

Results

Out of 1895 analyzed patients, 937 (49%) received intravenous iloprost treatment, while 958 (51%) were assigned to the control group. Among cases, about 70% were treated every 4 weeks, 24% with an interval of more than 4 weeks, and only 6% of less than 4 weeks. Most patients receiving the treatment every 4 weeks, or less, underwent infusion cycle for 1 day only, while if it was scheduled with an interval of more than 4 weeks, a total number of 5 consecutive days of infusions was the preferred regimen. The comparison between the two groups revealed that patients treated with intravenous iloprost had a higher frequency of DUs (p < 0.001), pitting scars (p < 0.001), diffuse cutaneous involvement (p < 0.001), interstitial lung disease (p < 0.002), as well as higher rates of anti-topoisomerase I, "late" scleroderma pattern at nailfold videocapillaroscopy. These findings were confirmed by multivariate analysis.

Conclusion

Our data provide a picture on the Italian use of intravenous iloprost among systemic sclerosis patients and showed that it was usually employed in patients with a more aggressive spectrum of the disease. The disparity of intravenous iloprost treatment strategies in the different centers suggests the need of a rational therapeutical approach based on the clinical characteristics of different patients' subsets.

Impact of Systemic Sclerosis-Associated Interstitial Lung Disease With and Without Pulmonary Hypertension on Survival: A Large Cohort Study of the German Network for Systemic Sclerosis

BACKGROUND

Pulmonary involvement is the leading cause of death in systemic sclerosis (SSc) and may manifest as interstitial lung disease (ILD), pulmonary arterial hypertension (PAH), or in combination of both (ILD with pulmonary hypertension [ILD-PH]). The aim of this analysis was to determine prevalence, clinical characteristics, and survival of these different forms within the registry of the German Network for Systemic Sclerosis.

RESEARCH QUESTION

Does SSc-associated ILD-PH or ILD without PH affect survival differently, and are there any risk factors that have an additional impact?

STUDY DESIGN AND METHODS

Clinical data of 5,831 patients with SSc were collected in the German Network for Systemic Sclerosis registry. Kaplan-Meier estimates were used to compare overall survival in patients with SSc-associated ILD-PH and ILD without PH with patients without pulmonary involvement and those with PAH. The Cox proportional hazard model was used to analyze the influence of pulmonary involvement and other potential predictors on patient survival.

RESULTS

Clinical data of 3,257 patients with a mean follow-up time of 3.45 ± 1.63 years have been included in our analysis. At baseline, ILD was present in 34.5%, whereas PH without ILD had a lower prevalence with 4.5%. At the end of follow-up, 47.6% of patients with SSc had ILD, 15.2% had ILD-PH, and 6.5% had PAH. ILD was more frequent in the diffuse cutaneous form (57.3%), whereas PAH did not differ significantly between SSc subtypes. Significant differences in baseline characteristics between PAH vs ILD-PH vs ILD without PH were found for age at diagnosis, sex, SSc subsets, antibody status, FVC, diffusing capacity of the lung for carbon monoxide, and therapy. Overall survival at 5 years was 96.4% for patients without pulmonary involvement and differed significantly between patients with ILD without PH, PAH, and being worst in patients with ILD-PH. Female sex (hazard ratio [HR], 0.3), higher BMI (HR, 0.9), and higher diffusing capacity of the lung for carbon monoxide values (HR, 0.98) were associated with a lower mortality risk.

INTERPRETATION

ILD is the most prevalent pulmonary involvement in SSc, whereas the combination of ILD and PH is associated with the most detrimental survival.