A score for predicting colchicine resistance at the time of diagnosis in familial Mediterranean fever: data from the TURPAID registry

Abstract

Abstract Objectives Colchicine forms the mainstay of treatment in FMF. Approximately 5–10% of FMF patients are colchicine resistant and require anti-IL-1 drugs. We aimed to compare the characteristics of colchicine-resistant and colchicine-responsive patients and to develop a score for predicting colchicine resistance at the time of FMF diagnosis. Methods FMF patients (0–18 years) enrolled in the Turkish Paediatric Autoinflammatory Diseases (TURPAID) registry were included. The predictive score for colchicine resistance was developed by using univariate/multivariate regression and receiver operating characteristics analyses. Results A total of 3445 FMF patients [256 (7.4%) colchicine-resistant and 3189 colchicine-responsive) were included (female:male ratio 1.02; median age at diagnosis 67.4 months). Colchicine-resistant patients had longer, more frequent attacks and were younger at symptom onset and diagnosis (P < 0.05). Fever, erysipelas-like erythema, arthralgia, arthritis, myalgia, abdominal pain, diarrhoea, chest pain, comorbidities, parental consanguinity and homozygosity/compound heterozygosity for exon 10 MEFV mutations were significantly more prevalent among colchicine-resistant than colchicine-responsive patients (P < 0.05). Multivariate logistic regression analysis in the training cohort (n = 2684) showed that age at symptom onset, attack frequency, arthritis, chest pain and having two exon 10 mutations were the strongest predictors of colchicine resistance. The score including these items had a sensitivity of 81.3% and a specificity of 49.1%. In the validation cohort (n = 671), its sensitivity was 93.5% and specificity was 53.8%. Conclusion We developed a clinician-friendly and practical predictive score that could help us identify FMF patients with a greater risk of colchicine resistance and tailor disease management individually at the time of diagnosis.