The relationship between red cell distribution width and homozygous M694V mutation in familial Mediterranean fever patients

BACKGROUND AND OBJECTIVE: Familial Mediterranean fever (FMF) is characterized by recurrent and self-limiting attacks with peritonitis, pleuritis, arthritis, and erysipelas-like erythema. We aimed to investigate the red cell distribution width (RDW) level as an inflammatory marker in FMF patients compared with normal subjects. DESIGN AND SETTINGS: A retrospective study of FMF patients at the Department of Gastroenterology, Cumhuriyet University, between November 2011-February 2013. METHODS: A total of 249 FMF patients and 131 age- and sex-matched control participants were included in the currrent study. RDW levels were also analyzed by standard methods. Each patient was given 2 mL of blood sample to obtain genomic DNA. RESULTS: Statistically significant differences were observed in RDW values between the FMF patients and the control group. Also, RDW levels were higher in the FMF patients with the homozygous M94V mutation compared with those with other mutations. The receiver-operating characteristic curve analysis suggested that the optimum RDW cutoff point for the FMF patients was 13.95, with a sensitivity, specificity, negative predictive value, and positive predictive value of 70%, 64%, 68%, and 66%, respectively (area under the curve: 0.711, 95% confidence interval 0.627–0.795, P<.0001). CONCLUSION: We suggest that RDW may show subclinical inflammation in FMF patients. RDW may be a promising marker in predicting the homozygous M694V mutation in FMF patients.