Tema Livre:

Extra-articular manifestations (EAMs) are highly prevalent in spondyloarthritis (SPA), and the most common are uveitis, psoriasis and inflammatory bowel disease (IBD). The aim of this study was to report the incidence of new EAMs in patients with SPA followed for 16 years and to identify possible associated factors.

Materials and methods

One hundred and fifty-six patients with SPA, according to the European SPA Study Group Criteria, were evaluated in a cross-sectional study in 2002. Of these, 67 patients were followed from 2002 to 2018 (16 years). The annual incidence (per 100 patient-year) of uveitis, psoriasis, IBD or any EAMs was calculated from symptoms onset to 2002. This was then compared to the incidence per 100 patient-year (PY) of new EAMs in the prospective cohort from 2002 to 2018. Factors associated with the incidence of new EAMs were also evaluated.

Results

Of the 67 patients evaluated, 42 (63%) were male, with a mean age of 42.3 ±12.1 years and 62.7% were HLA-B27 positive. At baseline, patients were classified as follows: 2 enteropathic arthritis, 6 psoriatic arthritis, 5 reactive arthritis, 41 ankylosing spondylitis and 13 undifferentiated SPA. At the end of follow-up, the prevalence of uveitis was 33 (49.2%), psoriasis 11 (16.4%), IBD 4 (5.9%) and any EAMs 44 (65.6%). Of the 33 cases of uveitis, 24 had presented at least one episode by 2002, an incidence of 2.31/100PY (95%CI 1.40-3.22). During follow-up, 9 new cases of uveitis were diagnosed, 1.14/100PY (95%CI 0.40-1.88). The main risk factor for the occurrence of uveitis was the presence of HLA-B27 (OR 3.1; 95%CI 1.1-8.9; p=0.04). Eight cases of psoriasis were found at the beginning of the study, 0.77/100PY (95%CI 0.24-1.30), and 3 new cases were found at follow-up, 0.41/100PY (95%CI 0-0.87). Predominant peripheral manifestations were associated with the occurrence of psoriasis (OR 96.25; 95%CI 9.38-988; p<0.0001), while HLA-B27 had an inverse association (OR 0.16; 95%CI 0.04-0.69; p=0.01). Two cases of IBD were seen up to 2002, 0.19/100PY (0-0.46), and two new cases occurred thereafter, incidence 0.28/100PY (0-0.67). No factor was associated with IBD.

Conclusion

In conclusion, the incidence of uveitis and psoriasis tended to decrease over time. As expected, uveitis was associated with the presence of HLA-B27 and psoriasis with peripheral involvement. Interestingly, HLA-B27, more associated with axial involvement, showed a negative association with psoriasis. The incidence of IBD tended to increase, but the small number of cases does not allow conclusions.