PREDICT-crFMF score: a novel model for predicting colchicine resistance in children with familial Mediterranean fever

Mod Rheumatol. 2023 Jan 21;road008. doi: 10.1093/mr/road008. Online ahead of print.


Objectives: To develop a novel scoring system based on the initial clinical features and laboratory findings for predicting colchicine resistance in familial Mediterranean fever (FMF).

Methods: The medical records including baseline clinical and laboratory findings of patients prior to initiation of colchicine were analyzed. After generating a predictive score in the initial cohort, it was applied to an independent cohort for external validation of effectiveness and reliability.

Results: Among 1418 patients with FMF, 56 (3.9%) were colchicine resistant (cr) and 1312 (96.1%) were colchicine responsive. According to the logistic regression analysis, recurrent arthritis(4-points), protracted febrile myalgia(8-points), erysipelas-like erythema (2-points), exertional leg pain(2-points), and carrying M694V homozygous mutation(4-points) were determined as the scoring parameters for predicting patients with cr-FMF. The cut-off value (9) was 87% sensitive and 82% specific to foresee the risk of colchicine resistance in the ROC. Validation of the scoring system with an independent group (cr-FMF=107, colchicine responsive=1935) revealed that the cut-off value was 82% sensitive and 79% specific to identify the risk of colchicine resistance.

Conclusions: By constructing this novel reliable predictor tool, we enunciate that predicting colchicine resistance in children with FMF at the initiation of the disease and interfering timely before the emergence of complications during the disease course will be possible.

Keywords: Colchicine resistance; erysipelas-like erythema; familial Mediterranean fever; predictive score; protracted febrile myalgia.