Background About 7 to 36% of AS patients report family history for spondyloarthritis in their first and second degree relatives (1). It is of interest whether AS patients receiving anti-TNF therapy, who may be considered as having more active disease, report a high prevalence of family history, and/or a high prevalence of strong family history, which is defined as having two first degree relatives with AS, for the purpose of this study.
Objectives The objective of this study was to assess the prevalence of family history among AS patients receiving biologic therapy, and to compare the patients with as strong family history with the rest of the patients who also reported family history.
Methods A total of 683 patients (mean age 41±13, males % 68.5) with AS from two centers, who contribute to TURKBIO, a biological database in Turkey, and who had collected detailed information on family history were included in this retrospective analysis. The data in regard with the family history were extracted from patients' hospital records without further validation, whereas the data for demographic characteristics, co-morbidities, smoking status, disease activity (BASDAI), functional status (BASFI), laboratory results (CRP, ESR) and all other assessment measures were obtained from the TURKBIO database.
Results A positive family was noted in 200 (31.3%) patients, with 84 patients (males 69.2%) having AS in a first degree relative (13.1%) and 20 patients reporting a strong family history (3.1%) (Table 1). The patients had a mean age of 41±13 years and mean disease duration of 11±7 years. Except for a higher female predominance in patients with strong family history than in the other patients with family history (55% vs 74%, p=0.034), there were no differences in regard with the demographic data, BASDAI and BASFI (baseline and last visit), TNFi survival, TNFi switch ratio were all similar between the two groups. HLA-B27 results were available in 9 of the 20 patients with strong family history and 55% of them were positive for HLA-B27.
Conclusions Prevalence of family history among AS patients on biologics seem to be similar to the figures reported in the literature. Disease characteristics among patients who have at least 2 relatives with AS do not seem to be different than the other patients having a less number or more distant relatives. It is of note convergence of HLA B27 with strong family history was not very high (55%), although it was tested in a very small number of patients.
Ann Rheum Dis 2004;63:535-543.
Disclosure of Interest None declared