Aim/purpose: Our aim was to investigate the association between blood groups and colchicine resistance in familial Mediterranean fever (FMF) patients.
Methods: This is a single-center, cross-sectional study. Between January and December 2016, 385 FMF patients were assessed by the Adult and Pediatric Rheumatology outpatient clinics and 297 patients had blood groups (ABO and Rh) results. The patients were grouped into two groups: colchicine-responsive patients (Group CR) and colchicine-unresponsive patients (Group CUR).
Results: Patients with blood group A had 1.5-fold higher FMF compared with non-A blood group (OR: 1.50 [95% CI: 1.11-1.87]), particularly having a Rh (+) blood group (OR: 1.47 [95% CI: 1.13-1.91]). Furthermore, patients with blood group A had a better response to colchicine treatment than non-A blood group; (OR: 2.21 [95% CI: 1.15-4.27]). Patients with blood group O were prominently associated with colchicine resistance.
Conclusion: ABO blood phenogroups may be used in combination with other risk factors to identify FMF patients and patients at high risk for colchicine resistance.
Keywords: blood group; colchicine; familial Mediterranean fever; treatment resistance; unresponsiveness.