THU0314 POLYAUTOIMMUNITY IN PATIENTS WITH SYSTEMIC SCLEROSISA. Rojas-Villarraga1, P. Coral-Alvarado2, R. D. Mantilla3, P. Chalem4, J. F. Restrepo2, F. Rondón2, E. Jauregui3, J. C. Rueda3, C. Cañas5, M. E. Hincapie1, R. Pineda-Tamayo1, F. Alvarez2, A. Iglesias-Gamarra2, J. M. Anaya6
1Cellular Biology and Immunogenetics, Corporación para Investigaciones Biológicas, Medellín, 2Rheumatology Unit, Universidad Nacional de Colombia, 3Rheumatology Unit, Clínica de Artritis y Rehabilitación (CAYRE), 4Rheumatology Unit, Fundación Instituto Reumatología e Inmunología (FIRI), Bogotá, 5Rheumatology Unit, Fundación Valle de Lily, Cali, 6Cellular Biology and Immunogenetics, Corporación para Investigaciones Biológicas-U. Rosario, Medellín, Colombia
Background: The etiology of autoimmune diseases (ADs) remains poorly understood; nevertheless common features among them and a plausible common background are recognized. Characterization of the extent to which particular combinations of ADs occur in excess of that expected by chance may offer new insights into its shared pathophysiological mechanisms.
Objectives: To investigate the co-occurrence of ADs (polyautoimmunity), and the family history of autoimmunity in patients with systemic sclerosis (SSc).
Methods: This was a multicenter study in which 287 consecutive patients with SSc followed at 5 rheumatology units were included and systematically assessed by using a standardized questionnaire that incorporated medical information including a check-point list of ADs and family history of autoimmunity. A multivariate analysis was performed to evaluate the association between polyautoimmunity and clinical and immunological variables of specific interest.
Results: 115 (40%) patients presented at least one other AD, including 89 (31%) with one, 25 (9%) with two and 1 (0.34%) with three AD in addition to their SSc. The first, second and third most frequent AD encountered were autoimmune thyroid disease (AITD) (n=61), Sjögren’s syndrome (n=33) and primary biliary cirrhosis (n=11), respectively. Familial autoimmunity was registered in 18 (15.7%) first degree relatives (FDR) of patients with SSc- polyautoimmunity, of whom 7 (39%) had RA (1 of them with AITD), 4 (22%) SLE (2 with vitiligo), 4 (22%) SSc, and 3 (16%) other ADs. Pertinent comparisons between SSc patients with and without polyautoimmunity are shown in the Table.
Table:
Characteristic
| SSc+ADs
N=115 (%) | SSc
N=172 (%) | AOR | 95%CI | p |
|
| Age | 55.1 ± 13.3 | 53.7 ± 12.8 | | | NS |
Duration of SS
yrs | 6.3 ± 5.5 | 6.8 ± 6.4 | | | NS |
Age at onset,
yrs | 48.7 ± 13.7 | 46.9 ± 13.4 | | | NS |
| Gender, woman | 113 (98.3) | 148 (86.1) | 9.08 | 2.19-39.3 | 0,003 |
Family
history of AD | 25 (21.7) | 18/170 (10.6) | 2.35 | 1.21-4.55 | 0,01 |
| FDR with AD | 18 (15.7) | 13 (7.7) | 2.31 | 1.1 – 4.96 | 0,03 |
|
Conclusion: Polyautoimmunity is frequent in patients with SSc, and ADs cluster within families of these patients. Collectively, our results indicate that clinically different autoimmune phenotypes might share common susceptibility variants, which acting in epistatic pleitropy may represent risk factors for autoimmunity.
