Efficacy and safety of tocilizumab in Japanese patients with systemic sclerosis and associated interstitial lung disease: A subgroup analysis of a global, randomised, controlled Phase 3 trial

OBJECTIVES

The aim of this article is to investigate the efficacy and safety of tocilizumab in Japanese patients with systemic sclerosis.

METHODS

Post hoc subgroup analysis of a global, randomised, controlled trial in patients treated with weekly tocilizumab 162 mg or placebo subcutaneously in a 48-week double-blind period (tocilizumab and placebo groups) followed by tocilizumab for 48 weeks in an open-label extension (continuous-tocilizumab and placebo-tocilizumab groups).

RESULTS

Among 20 patients, 12 were randomised to tocilizumab (all had interstitial lung disease) and eight were randomised to placebo (six had interstitial lung disease). The modified Rodnan skin score improved in both treatment groups. The mean change in percent-predicted forced vital capacity was 3.3% [95% confidence interval (CI), -2.5 to 9.0] for tocilizumab and -3.8% (95% CI, -9.9 to 2.2) for placebo in the double-blind period and 2.0% (95% CI, -0.7 to 4.6) for continuous-tocilizumab and -1.4% (95% CI, -6.7 to 4.0) for placebo-tocilizumab in the open-label extension. Rates of serious adverse events per 100 patient-years were 19.3 for tocilizumab and 26.8 for placebo in the double-blind period and 0.0 for continuous-tocilizumab and 13.6 for placebo-tocilizumab in the open-label period.

CONCLUSIONS

The efficacy and safety of tocilizumab in patients with systemic sclerosis were consistent between the Japanese subpopulation and the global trial population.

Nintedanib Therapy Alone and Combined with Mycophenolate in Patients with Systemic Sclerosis-associated Interstitial Lung Disease: Systematic Reviews and Meta-analysis

Background: The American Thoracic Society convened an international multidisciplinary panel to develop clinical practice guidelines for the treatment of systemic sclerosis-associated interstitial lung disease (SSc-ILD). Objective: To conduct a systematic review and evaluate the literature to determine whether patients with SSc-ILD should be treated with nintedanib alone or with the combination of nintedanib plus mycophenolate. Data Sources: Literature searches were conducted across MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials databases through June 2022 for studies using nintedanib or nintedanib plus mycophenolate to treat patients with SSc-ILD. Data Extraction: Mortality, disease progression, quality of life, and adverse event data were extracted, and meta-analysis was performed when possible. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) Working Group method was used to assess the quality of evidence. Synthesis: For nintedanib therapy alone, the systematic review included three total studies and revealed that disease progression was less in the nintedanib arm (the annual rate of decline in forced vital capacity [FVC] was 44.5 ml less, the absolute change from baseline was 46.4 ml less, and FVC% predicted was 1.2% less in the nintedanib arm) compared with placebo. However, gastrointestinal side effects and treatment discontinuation were double in the nintedanib arm compared with placebo. For combination therapy, the systematic review also included three total studies and revealed that changes in the annual rate of decline in FVC favored combination therapy over placebo (mean difference, 79.1 ml). Combination therapy was, however, associated with increased gastrointestinal adverse effects compared with placebo. The quality of evidence for all outcomes was very low as per GRADE. Conclusions: The use of nintedanib alone and in combination with mycophenolate in patients with SSc-ILD is associated with a significant reduction in disease progression compared with placebo but at the cost of increased gastrointestinal side effects and treatment discontinuation. The quality of evidence is very low.

Serum C-reactive protein is associated with earlier mortality across different interstitial lung diseases

BACKGROUND AND OBJECTIVE

The acute-phase protein C-reactive protein (CRP) is known to be associated with poor outcomes in cancer and cardiovascular disease, but there is limited evidence of its prognostic implications in interstitial lung diseases (ILDs). We therefore set out to test whether baseline serum CRP levels are associated with mortality in four different ILDs.

METHODS

In this retrospective study, clinically measured CRP levels, as well as baseline demographics and lung function measures, were collected for ILD patients first presenting to the Royal Brompton Hospital between January 2010 and December 2019. Cox regression analysis was used to determine the relationship with 5-year mortality.

RESULTS

Patients included in the study were: idiopathic pulmonary fibrosis (IPF) n = 422, fibrotic hypersensitivity pneumonitis (fHP) n = 233, rheumatoid arthritis associated ILD (RA-ILD) n = 111 and Systemic Sclerosis associated ILD (SSc-ILD) n = 86. Patients with a recent history of infection were excluded. Higher CRP levels were associated with shorter 5-year survival in all four disease groups on both univariable analyses, and after adjusting for age, gender, smoking history, immunosuppressive therapy and baseline disease severity (IPF: HR (95% CI): 1.3 (1.1-1.5), p = 0.003, fHP: 1.5 (1.2-1.9), p = 0.001, RA-ILD: 1.4 (1.1-1.84), p = 0.01 and SSc-ILD: 2.7 (1.6-4.5), p < 0.001).

CONCLUSION

Higher CRP levels are independently associated with reduced 5-year survival in IPF, fHP, RA-ILD and SSc-ILD.

Tocilizumab in Patients with Systemic Sclerosis-associated Interstitial Lung Disease: A Systematic Review and Meta-Analysis

Background: The American Thoracic Society (ATS) convened an international, multidisciplinary panel to develop clinical practice guidelines for the treatment of systemic sclerosis-associated interstitial lung disease (SSc-ILD). Objective: To conduct a systematic review and evaluate the literature to determine the impact of treating patients with SSc-ILD with tocilizumab on prespecified critical and important outcomes determined by the ATS guideline panel. Data Sources: A literature search was conducted across MEDLINE, EMBASE, and Cochrane databases through June 2022 for studies using tocilizumab to treat patients with SSc-ILD. Data Extraction: Mortality and disease progression were determined to be critical outcomes of focus, with quality of life and adverse events important outcomes. Data on these outcomes were extracted and meta-analyses performed using the generic inverse variance method when possible. The Grading of Recommendations, Assessment, Development, and Evaluation Working Group method was used to assess the quality of evidence. Synthesis: The literature review resulted in five studies for inclusion. The absolute decrease from baseline in forced vital capacity (FVC) for the tocilizumab arm was 118 ml, 241 ml, and 129 ml less than the placebo arm at 24, 48, and 96 weeks, respectively, favoring tocilizumab. The mean decrease in FVC% predicted at 48 weeks was 6.50% less and the risk of decrease >10% was 66% less in the tocilizumab arm, whereas patients were 1.97 times more likely to have any increase in FVC% predicted if they received tocilizumab in place of placebo. When the placebo arm was given tocilizumab from 48 to 96 weeks, the mean change in absolute FVC was 54.90 ml less and the mean change in FVC% predicted was 1.30% less. For diffusing capacity of the lung for carbon monoxide (DlCO)% predicted, at 48 weeks there was 1.50% less change and from 48 to 96 weeks there was 5.40% less change in the tocilizumab arm. Quantitative Interstitial Lung Disease scores and Quantitative Lung Fibrosis scores at 48 weeks and modified Rodnan skin scores at 72 weeks all favored the tocilizumab arm, as did several adverse event parameters, including serious adverse events (mean difference, -27.40; 95% confidence interval, -30.10 to -24.70). The quality of evidence was very low grade. Conclusions: Tocilizumab use in patients with SSc-ILD is associated with less disease progression and a better toxicity profile than placebo. However, the quality of evidence is very low, and large prospective studies dedicated to assessing tocilizumab specifically for SSc-ILD are needed.

Rituximab in Patients with Systemic Sclerosis-associated Interstitial Lung Disease: A Systematic Review and Meta-Analysis

Background: The American Thoracic Society convened an international, multidisciplinary panel to develop clinical practice guidelines for the treatment of systemic sclerosis-associated interstitial lung disease (SSc-ILD). Objective: To conduct a systematic review and evaluate the literature to determine whether patients with SSc-ILD should be treated with rituximab. Data Sources: A literature search was conducted across MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials (CENTRAL) databases through June 2022 for studies using rituximab to treat patients with SSc-ILD. Data Extraction: Disease progression, quality of life, mortality, and adverse event data were extracted. The intervention was rituximab. The standard-of-care comparator group was decided a priori by consensus of the panel as either placebo or mycophenolate. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) Working Group approach was used to assess the quality of evidence. Synthesis: Three relevant studies were selected. Rituximab significantly improved the forced vital capacity % predicted (mean difference, 3.13; 95% confidence interval [CI], 0.37 to 5.90) and the modified Rodnan Skin Score (mean difference, -7.01; 95% CI, 11.46 to -2.56) at 24-48 weeks. Conclusions: Rituximab use in patients with SSc-ILD is associated with stabilization of lung function. The quality of evidence for study outcomes was considered to be very low, as defined by the GRADE approach. Additional research on treatment with rituximab is imperative.

Treatment of Systemic Sclerosis-associated Interstitial Lung Disease: Evidence-based Recommendations. An Official American Thoracic Society Clinical Practice Guideline

Background: Interstitial lung disease (ILD) is a significant cause of morbidity and mortality in patients with systemic sclerosis (SSc). To date, clinical practice guidelines regarding treatment for patients with SSc-ILD are primarily consensus based. Methods: An international expert guideline committee composed of 24 individuals with expertise in rheumatology, SSc, pulmonology, ILD, or methodology, and with personal experience with SSc-ILD, discussed systematic reviews of the published evidence assessed using the Grading of Recommendations, Assessment, Development, and Evaluation approach. Predetermined conflict-of-interest management strategies were applied, and recommendations were made for or against specific treatment interventions exclusively by the nonconflicted panelists. The confidence in effect estimates, importance of outcomes studied, balance of desirable and undesirable consequences of treatment, cost, feasibility, acceptability of the intervention, and implications for health equity were all considered in making the recommendations. This was in accordance with the American Thoracic Society guideline development process, which is in compliance with the Institute of Medicine standards for trustworthy guidelines. Results: For treatment of patients with SSc-ILD, the committee: 1) recommends the use of mycophenolate; 2) recommends further research into the safety and efficacy of (a) pirfenidone and (b) the combination of pirfenidone plus mycophenolate; and 3) suggests the use of (a) cyclophosphamide, (b) rituximab, (c) tocilizumab, (d) nintedanib, and (e) the combination of nintedanib plus mycophenolate. Conclusions: The recommendations herein provide an evidence-based clinical practice guideline for the treatment of patients with SSc-ILD and are intended to serve as the basis for informed and shared decision making by clinicians and patients.

Mycophenolate in Patients with Systemic Sclerosis-associated Interstitial Lung Disease: A Systematic Review and Meta-Analysis

Rationale: The American Thoracic Society convened an international, multidisciplinary panel to develop clinical practice guidelines for the treatment of systemic sclerosis-associated interstitial lung disease (SSc-ILD). Objective: To conduct a systematic review and evaluate the literature to determine whether patients with SSc-ILD should be treated with mycophenolate. Methods: A literature search was conducted across the MEDLINE, EMBASE, and CENTRAL databases through June 2022 for studies using mycophenolate to treat patients with SSc-ILD. Mortality, disease progression, quality of life, and adverse event data were extracted, and meta-analyses were performed when possible. The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) Working Group method was used to assess the quality of evidence. Results: The literature review resulted in seven studies fitting the inclusion criteria. The systematic review and meta-analyses revealed changes in forced vital capacity % predicted (mean difference [MD], 5.4%; 95% confidence interval [95% CI]: 3.3%, 7.5%), diffusing capacity of the lung for carbon monoxide % predicted (MD, 4.64%; 95% CI: 0.54%, 8.74%), and breathlessness score (MD, 1.99; 95% CI: 0.36, 3.62) favored mycophenolate over placebo. The risk of anemia (relative risk [RR], 2.3; 95% CI: 1.2, 71.4) was higher with mycophenolate. There were no significant differences between mycophenolate and cyclophosphamide, except risk of premature discontinuation (RR, 0.6; 95% CI: 0.4, 0.9), and leukopenia (RR, 0.1; 95% CI: 0.05, 0.4) favored mycophenolate. The quality of evidence was moderate to very low per GRADE. Conclusions: Mycophenolate use in patients with SSc-ILD is associated with statistically significant improvements in disease progression and quality-of-life measures compared with placebo. There were no differences in mortality, disease progression, or quality of life compared with cyclophosphamide, but there were fewer adverse events. The quality of evidence is very low.

Cyclophosphamide in Patients with Systemic Sclerosis-associated Interstitial Lung Disease: A Systematic Review and Meta-Analysis

Background: The American Thoracic Society convened an international, multidisciplinary panel to develop clinical practice guidelines for the treatment of systemic sclerosis-associated interstitial lung disease (SSc-ILD). Objective: To conduct a systematic review and evaluate the literature to determine whether patients with SSc-ILD should be treated with cyclophosphamide. Data Sources: A literature search was conducted across the MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials databases through June 2022 for studies using cyclophosphamide to treat patients with SSc-ILD. Data Extraction: Mortality, disease progression, quality of life, and adverse event data were extracted, and meta-analyses were performed when possible. The Grading of Recommendations, Assessment, Development and Evaluation Working Group method was used to assess the quality of evidence. Synthesis: Five studies were included; two randomized controlled trials compared cyclophosphamide versus placebo, and one randomized controlled trial and two retrospective case-control studies compared cyclophosphamide versus mycophenolate. Compared with placebo, there was a 2.83% reduction in the decline at 12 months for forced vital capacity (FVC) % predicted using cyclophosphamide (95% confidence interval [CI], 0.80-4.87; low evidence). There were improvements in breathlessness (Transition Dyspnea Index mean difference [MD], 2.90; 95% CI, 1.94-3.86; minimum clinically important difference, 1; moderate evidence) and disability (Health Assessment Questionnaire-Disability Index MD, -0.16; 95% CI, -0.28 to -0.04; minimum clinically important difference, -0.14; moderate evidence). There were increased risks of leukopenia and constitutional symptoms using cyclophosphamide, but no difference in mortality. When cyclophosphamide was compared with mycophenolate, there were differences in diffusing capacity of the lung for carbon monoxide % predicted favoring mycophenolate at 6 months (MD, -3.67%; 95% CI, -6.3% to -1.1% unadjusted; MD, -4.88%; 95% CI, -7.3% to -2.5% adjusted for alveolar volume; moderate evidence), 12 months (MD, -5.90%; 95% CI, -8.4% to -3.4% adjusted for alveolar volume; moderate evidence), and 18 months (MD, -3.26%; 95% CI, -6.1% to -0.4%; moderate evidence), but not at 24 months. There were no differences in FVC % predicted, mortality, or quality-of-life outcomes, but participants were more likely to prematurely discontinue cyclophosphamide compared with mycophenolate (relative risk, 1.70; 95% CI, 1.10-2.63; high-certainty evidence). Conclusions: A review of the published evidence shows that cyclophosphamide is effective in SSc-ILD compared with placebo, with an increased risk of side effects. However, mycophenolate may be equivocal or better than cyclophosphamide. Clinicians and patients should weigh the potential benefits and risks with respect to individual patient circumstances and preferences.

The Role of Autophagy and Apoptosis in Affected Skin and Lungs in Patients with Systemic Sclerosis

Systemic sclerosis (SSc) is a complex autoimmune inflammatory disorder with multiple organ involvement. Skin changes present the hallmark of SSc and coincide with poor prognosis. Interstitial lung diseases (ILD) are the most widely reported complications in SSc patients and the primary cause of death. It has been proposed that the processes of autophagy and apoptosis could play a significant role in the pathogenesis and clinical course of different autoimmune diseases, and accordingly in SSc. In this manuscript, we review the current knowledge of autophagy and apoptosis processes in the skin and lungs of patients with SSc. Profiling of markers involved in these processes in skin cells can be useful to recognize the stage of fibrosis and can be used in the clinical stratification of patients. Furthermore, the knowledge of the molecular mechanisms underlying these processes enables the repurposing of already known drugs and the development of new biological therapeutics that aim to reverse fibrosis by promoting apoptosis and regulate autophagy in personalized treatment approach. In SSc-ILD patients, the molecular signature of the lung tissues of each patient could be a distinctive criterion in order to establish the correct lung pattern, which directly impacts the course and prognosis of the disease. In this case, resolving the role of tissue-specific markers, which could be detected in the circulation using sensitive molecular methods, would be an important step toward development of non-invasive diagnostic procedures that enable early and precise diagnosis and preventing the high mortality of this rare disease.

Exploring the common pathophysiological links between IPF, SSc-ILD and post-COVID fibrosis

In coronavirus disease 2019 (COVID-19) patients, dysregulated release of matrix metalloproteinases occurs during the inflammatory phase of acute respiratory distress syndrome (ARDS), resulting in epithelial and endothelial injury with excessive fibroproliferation. COVID-19 resembles idiopathic pulmonary fibrosis (IPF) in several aspects. The fibrotic response in IPF is driven primarily by an abnormally activated alveolar epithelial cells (AECs) which release cytokines to activate fibroblasts. Endoplasmic reticulum (ER) stress is postulated to be one of the early triggers in both diseases. Systemic sclerosis (SSc) is a heterogeneous autoimmune rare connective tissue characterised by fibrosis of the skin and internal organs. Interstitial lung disease (ILD) is a common complication and the leading cause of SSc-related death. Several corollaries have been discussed in this paper for new drug development based on the pathogenic events in these three disorders associated with pulmonary fibrosis. A careful consideration of the similarities and differences in the pathogenic events associated with the development of lung fibrosis in post-COVID patients, IPF patients and patients with SSc-ILD may pave the way for precision medicine. Several questions need to be answered through research, which include the potential role of antifibrotics in managing IPF, SSc-ILD and post-COVID fibrosis. Many trials that are underway will ultimately shed light on their potency and place in therapy.

[Importance of mycophenolate mofetil for treatment of interstitial lung disease in systemic sclerosis]

Interstitial lung disease in systemic sclerosis (SSc-ILD) is a frequent organ complication with considerable mortality. Therapeutically, immunosuppressants are primarily used, particularly cyclophosphamide (CYC) and mycophenolate mofetil (MMF). Recently acquired data also showed an efficacy of the biologics rituximab and tocilizumab. The therapeutic options have most recently been expanded by the approval of the antifibrotic drug nintedanib. It is particularly beneficial in progressive fibrosing courses of ILD despite immunosuppression. The data from controlled trials on the efficacy and safety of CYC and MMF compiled in this review argue for a preferential use of MMF; however, the approval of MMF for this indication is still lacking. This is urgently needed for improved and simplified care of patients with SSc-ILD.

Healthcare Resource Utilization Among Patients in England with Systemic Sclerosis-Associated Interstitial Lung Disease: A Retrospective Database Analysis

INTRODUCTION

Systemic sclerosis-associated interstitial lung disease (SSc-ILD) places a substantial burden on patients and healthcare systems. The objectives of this study were to describe clinical characteristics and assess healthcare resource utilization and costs of patients with SSc-ILD in England, compared with patients with non-pulmonary organ involvement related to SSc (SSc-OOI).

METHODS

This population-based retrospective study used data from the Clinical Practice Research Datalink linked to Hospital Episode Statistics. Data were extracted from medical records dated January 1, 2005 to March 31, 2016. Patients with SSc were identified and placed in subgroups based on organ involvement: SSc-ILD, SSc-OOI, and both (SSc-ILD-OOI). Patients with SSc-ILD-OOI were included in both the SSc-ILD and SSc-OOI subgroups. All-cause healthcare costs, excluding medication costs, were calculated to 2016 British pounds sterling (£).

RESULTS

This study included 675 patients with SSc: 174 (26%) had neither ILD nor other organ involvement (OOI); 127 (19%) had SSc-ILD; 477 (71%) had SSc-OOI; 103 (15%) had SSc-ILD-OOI. Age-weighted median [interquartile range (IQR)] annual healthcare costs per patient were: £1496 (£664-£2817) in SSc only; £6375 (£3451-£15,041) in SSc-ILD; £4084 (£1454-£10,105) in SSc-OOI; £6632 (£4023-£17,009) in SSc-ILD-OOI. In multivariate analysis, older age at diagnosis, diagnosis of anemia, and number of comorbid diseases were associated with higher yearly healthcare costs.

CONCLUSION

The annual healthcare cost for patients with SSc-ILD is substantial, and higher than that of patients with SSc-OOI or SSc only. These results quantify the economic burden of SSc-ILD in a real-world setting, and highlight the need for treatment of this disease.

Nintedanib in patients with systemic sclerosis-associated interstitial lung disease: A Japanese population analysis of the SENSCIS trial

OBJECTIVE

We examined the efficacy and safety of nintedanib in Japanese patients with systemic sclerosis-associated interstitial lung disease (SSc-ILD) in the global Safety and Efficacy of Nintedanib in Systemic Sclerosis (SENSCIS) trial.

METHODS

Randomised patients received oral nintedanib 150 mg (N = 34) twice daily or placebo (N = 36) until the last patient reached 52 weeks of treatment (up to 100 weeks). Data were analysed using a subgroup analysis model with Japanese and non-Japanese patients as subgroup variables.

RESULTS

In Japanese patients, the adjusted annual rate of forced vital capacity (FVC) decline over 52 weeks was -86.2 mL/year (nintedanib) and -90.9 mL/year (placebo); treatment difference, 4.67 mL/year (95% confidence interval, -103.28, 112.63). Treatment effect heterogeneity between Japanese and non-Japanese patients was not detected (treatment-by-visit-by-subgroup interaction; p = .49). FVC decline was smaller for nintedanib versus placebo through 100 weeks in Japanese patients. The most commonly reported adverse events with nintedanib were gastrointestinal and liver disorder events; most were mild-to-moderate in severity.

CONCLUSION

In both Japanese and non-Japanese patients with SSc-ILD, nintedanib slowed the progression of ILD, with no heterogeneity detected between the subgroups. The safety profile for nintedanib in Japanese patients was similar to that observed in patients with idiopathic pulmonary fibrosis (ClinicalTrials.gov: NCT02597933).

Biomarkers in systemic sclerosis-associated interstitial lung disease: review of the literature

SSc is a rare disease of unknown origin associated with multiple organ involvement. One of the major complications that drives the mortality of SSc patients is interstitial lung disease. The course of SSc-interstitial lung disease progression has a wide spectrum. Since the treatment is based on aggressive immunosuppression it should not be given to stable or non-progressing disease. The correct identification of disease with high risk of progression remains a challenge for early therapeutic intervention, and biomarkers remain urgently needed. In fact, eight categories of biomarkers have been identified and classified according to the different biological pathways involved. The purpose of this article is to describe the main biomarkers thought to be of interest with clinical value in the diagnosis and prognosis of SSc-interstitial lung disease.

Defining genetic risk factors for scleroderma-associated interstitial lung disease : IRF5 and STAT4 gene variants are associated with scleroderma while STAT4 is protective against scleroderma-associated interstitial lung disease

Although several genetic associations with scleroderma (SSc) are defined, very little is known on genetic susceptibility to SSc-associated interstitial lung disease (SSc-ILD). A number of common polymorphisms have been associated with SSc-ILD, but most have not been replicated in separate populations. Four SNPs in IRF5, and one in each of STAT4, CD226 and IRAK1, selected as having been previously the most consistently associated with SSc-ILD, were genotyped in 612 SSc patients, of European descent, of whom 394 had ILD. The control population (n = 503) comprised individuals of European descent from the 1000 Genomes Project. After Bonferroni correction, two of the IRF5 SNPs, rs2004640 (OR (95% CI)1.30 (1.10–1.54), p^corr = 0.015) and rs10488631 (OR 1.48 (1.14–1.92), p^corr = 0.022), and the STAT4 SNP rs7574865 (OR 1.43 (1.18–1.73), p^corr = 0.0015) were significantly associated with SSc compared with controls. However, none of the SNPs were significantly different between patients with SSc-ILD and controls. Two SNPs in IRF5, rs10488631 (OR 1.72 (1.24–2.39), p^corr = 0.0098), and rs2004640 (OR 1.39 (1.11–1.75), p^corr = 0.03), showed a significant difference in allele frequency between controls and patients without ILD, as did STAT4 rs7574865 (OR 1.86 (1.45–2.38), p^corr = 6.6 × 10⁻⁶). A significant difference between SSc with and without ILD was only observed for STAT4 rs7574865, being less frequent in patients with ILD (OR 0.66 (0.51–0.85), p^corr = 0.0084). In conclusion, IRF5 rs2004640 and rs10488631, and STAT4 rs7574865 were significantly associated with SSc as a whole. Only STAT4 rs7574865 showed a significant difference in allele frequency in SSc-ILD, with the T allele being protective against ILD.

Key points • We confirm the associations of the IRF5 SNPs rs2004640 and rs10488631, and the STAT4 SNP rs7574865, with SSc as a whole. • None of the tested SNPs were risk factors for SSc-ILD specifically. • The STAT4 rs7574865 T allele was protective against the development of lung fibrosis in SSc patients. • Further work is required to understand the genetic basis of lung fibrosis in association with scleroderma.