Clinical characteristics and outcomes of 566 Thais with systemic sclerosis: A cohort study.

BACKGROUND

Most Thai patients with systemic sclerosis (SSc) have diffuse cutaneous SSc (dcSSc) unlike most Caucasians and some Asians. A longitudinal cohort study among Thai dcSSc is needed.

OBJECTIVES

We aimed to determine the overall clinical characteristics, define the clinical difference between limited cutaneous SSc (lcSSc) and dcSSc, and ascertain the mortality rate and the factors associated with mortality.

METHOD: We conducted a cohort study including 566 Thai adult SSc patients between January 2013 and June 2019. Clinical difference between lcSSc and dcSSc was investigated using generalized estimating equations (GEE).

RESULTS

Females presented more than males (356 vs 210 cases). The majority of cases were dcSSc (411; 72.6%). The median duration of disease at the time of pulmonary fibrosis (PF) detection was 2.5 years, pulmonary arterial hypertension 8.1 years, and renal crisis 4.1 years. By GEE analysis, dcSSc was significantly associated with salt-and-pepper skin, hand deformity, and every 1-point increase in modified Rodnan skin score (mRSS). A greater mortality risk was associated with age at onset >60 years (hazards ratio [HR] 5.5), a World Health Organization functional class (FC) III (HR 5.1), FC IV (HR 34.8), edematous skin (HR 11.4), early onset of PF (HR 1.7), each 5-point increase in the mRSS (HR 4.5), and ≥2 internal organ involvements (HR 10.1).

CONCLUSION

dcSSc is a common SSc subset among Thais. PF was an early complication in SSc and earlier PF detection was associated with a poorer prognosis. Elderly onset, high FC, severe skin tightness, and multiple organ involvements were associated with a greater mortality risk.