Incidence and predictors of interstitial lung disease (ILD) in Thai patients with early systemic sclerosis: Inception cohort study.

OBJECTIVES

To determine and compare the prevalence of interstitial lung disease (ILD), the severity of high-resolution computed tomography (HRCT) score and incidence rate (IR) of ILD between the two subsets of early-SSc (systemic sclerosis) patients. We also determined the factors associated with ILD.

METHODS

We used an inception cohort of early-SSc patients seen between January 2010 and June 2014. All patients underwent HRCT at study entry and annually thereafter.

RESULTS

One hundred and thirteen patients (66 females and 89 diffuse cutaneous SSc [dcSSc]) with a mean ± SD age of 53.4 ± 8.4 years and mean disease duration of 12.9 ± 10.3 months at cohort entry were enrolled. At enrollment, patients with dcSSc had a higher prevalence of ILD (78.7% vs. 45.8%, p = 0.002), and a higher total HRCT score (10.3 ± 9.5 vs. 4.4 ± 5.6, p = 0.001) compared with limited cutaneous SSc (lcSSc). DcSSc patients had a higher IR of ILD than lcSSc patients (58.8 vs.17.3 per 100 person-years, p < 0.001). Univariable analysis revealed that male gender, presence of anti-Scl 70 and absent anti-centromere antibody was significant predictors of ILD. In Cox-regression analysis, a positive anti-centromere [hazard ratio (HR) 0.09 95% confidence interval (95% CI 0.01-0.73)] was a protective factor.

CONCLUSIONS

DcSSc patients had more severe HRCT scores and higher IR of ILD compared with lcSSc patients. Male gender, presence of anti-Scl 70, and absent anti-centromere antibody predicted the future development of ILD in early-SSc patients.