Nearly 56% of heterozygous patients with familial Mediterranean fever who discontinued colchicine therapy sustained remission during follow-up, with lower levels of biomarkers S100A8/A9 and S100A12 observed in this group, according to a recent study.

Researchers conducted a multicenter study, published in RMD Open, to evaluate inflammatory biomarkers in patients with familial Mediterranean fever (FMF), focusing on genotype-specific disease activity and the feasibility of colchicine discontinuation in heterozygous cases. Data from 747 patients were analyzed across two European registries: AID-Net and JIRcohort. The researchers examined classical biomarkers such as C-reactive protein (CRP) and serum amyloid A (SAA), and two novel biomarkers: S100A8/A9 and S100A12.

The researchers then stratified the patients by genotype: 233 homozygous, 201 compound heterozygous, and 224 heterozygous with one class IV-V mutation. Biomarker levels were assessed during active, subclinical, and inactive disease states. Homozygous patients exhibited higher median levels of SAA, ESR, S100A8/A9, and S100A12 during inactive visits compared with other genotypes. Pairwise analysis indicated that heterozygous patients had notably lower levels of S100A8/A9 and S100A12 compared with compound heterozygous patients (P < .001).

Colchicine discontinuation was attempted in 52 heterozygous patients, with 56% (n = 29) achieving remission during a median follow-up of 12 months. Colchicine was reintroduced in 44% (n = 23) of the patients, with a median reintroduction time of 1.92 years. Despite the positive findings, the researchers emphasized that longer follow-up and further studies are needed to validate the results of the study and to refine criteria for discontinuation.

The study concluded that S100A8/A9 and S100A12 are valuable biomarkers for assessing FMF activity, reflecting gene-dose effects and correlating with genotype severity. While heterozygous patients exhibited milder disease profiles, the clinical implications for colchicine management remained exploratory.

Full disclosures can be found in the published study.