OBJECTIVE: Familial Mediterranean Fever (FMF) is a hereditary disease characterized by recurrent inflammatory attacks. A subclinical inflammation may persist in periods between the attacks and heterozygotes may have higher than normal levels of acute phase proteins. We investigated the levels of interleukin-6 (IL-6) and its soluble receptor (sIL-6R) in FMF patients and their obligatory carrier relatives. METHODS: Serum levels of IL-6 and sIL-6R were measured during acute attacks (n = 18) and in attack-free FMF patients (n = 26), obligatory carriers of FMF (n = 17) and normal controls (n = 11). RESULTS: The median levels of IL-6 were significantly higher (45.71 pg/ mL, p = 0.001) during acute attacks of FMF only, and were normal (0.01 pg/ mL) in the other groups studied. There was no statistically significant difference in the median sIL-6R values between any of the groups (p = 0.22). CONCLUSION: IL-6 was extremely elevated during FMF attacks but could not detect hypothetical "subclinical" inflammation during attack-free intervals or in the heterozygote relatives of patients. Serum levels of sIL-6R were comparable in all four groups.
OBJECTIVE:Familial Mediterranean Fever (FMF) is a hereditary disease characterized by recurrent inflammatory attacks. A subclinical inflammation may persist in periods between the attacks and heterozygotes may have higher than normal levels of acute phase proteins. We investigated the levels of interleukin-6 (IL-6) and its soluble receptor (sIL-6R) in FMFpatients and their obligatory carrier relatives. METHODS: Serum levels of IL-6 and sIL-6R were measured during acute attacks (n = 18) and in attack-free FMFpatients (n = 26), obligatory carriers of FMF (n = 17) and normal controls (n = 11). RESULTS: The median levels of IL-6 were significantly higher (45.71 pg/ mL, p = 0.001) during acute attacks of FMF only, and were normal (0.01 pg/ mL) in the other groups studied. There was no statistically significant difference in the median sIL-6R values between any of the groups (p = 0.22). CONCLUSION:IL-6 was extremely elevated during FMF attacks but could not detect hypothetical "subclinical" inflammation during attack-free intervals or in the heterozygote relatives of patients. Serum levels of sIL-6R were comparable in all four groups.