Distinctive autoantibody profile in Mexican Mestizo systemic sclerosis patients

Abstract

Systemic sclerosis (SSc) shows variable clinical expression among different ethnic groups. Herein, we describe the clinical features, prevalence of organ involvement, and autoantibody profile in Mexican Mestizo SSc patients and we compare them with patients from other ethnic groups.We included 139 SSc patients. They underwent clinical evaluation and were tested for antinuclear antibodies (ANA), anticentromere antibodies (ACA), anti-topoisomerase I, anti-RNA polymerase III, anti-U1 RNP, anti-U3 RNP, anti-U11/U12 RNP, anti-Th/To, anti-PM-Scl, anti-Ku, antinucleosome, anti-double-stranded DNA (dsDNA), anti-Sm, anti-SSA, and anti-SSB antibodies. Female predominance (93.5%) was noted; 56.8% of patients had limited cutaneous SSc; 91% had peripheral vascular involvement; 70% had joint involvement; 27% had musculoskeletal damage; 66% had gastrointestinal involvement; 41% had interstitial lung disease; 32% had pulmonary arterial hypertension (PAH); 11% had cardiac involvement; and in 1.4% renal involvement was observed. Our patients showed lower frequency of renal crisis and higher frequency of PAH than patients from other ethnic groups; also they showed higher frequency of ACA than Japanese and African American patients, higher frequency of anti-topoisomerase I than Caucasian and African American patients, higher frequency of anti-PM-Scl and anti-Ku and lower frequency of anti-RNA Pol III than the other ethnic groups. High frequencies of antinucleosome (41%) and anti-dsDNA (63%) were identified. SSc-specific autoantibody frequencies are different in our patients and in those from other ethnic groups; associations of autoantibodies with clinical manifestations are confirmed in our patients. Ethnicity and the interaction of gene and environmental factors may influence the clinical picture and autoantibody profile in SSc patients.

Keywords::

• systemic sclerosis
• autoantibodies
• antinucleosome
• Mexican Mestizo
• Hispanic

Acknowledgements

We thank the support of INOVA diagnostics for providing the anti-RNA polymerase III kit.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.