Effect of Helicobacter pylori infection and eradication therapy on interleukin-6 levels in patients with Familial Mediterranean Fever.

ABSTRACT

It is being questioned if Helicobacter pylori infection, which causes a chronic inflammatory response, can increase the frequency and severity of attacks in patients with Familial Mediterranean Fever (FMF) and if the impact of inflammatory response can be diminished by eradication of the infection. To evaluate if there is difference in interleukin (IL)-6 levels of H. pylori-positive and -negative patients both before and during FMF attacks; if there is a change in IL-6 levels following successful eradication treatment; and if MEFV gene mutations have an effect on IL-6 levels. IL-6 levels were evaluated in 47 FMF patients before and during FMF attacks. Genetic testing to determine M694V, M694I, E148Q, V726V, M680I mutations was also performed in all patients. IL-6 levels were also determined after successful eradication of the infection in H. pylori-positive patients. IL-6 levels were compared in H. pylori-positive and -negative patients, and before and after eradication treatment in patients who cleared the infection. Number of patients in tested mutation groups was not enough to compare IL-6 levels in these groups. Thirty-four patients (73.9%) were H. pylori-positive. Before FMF attack there was no statistically significant difference in IL-6 levels of H. pylori-positive and -negative groups. IL-6 levels were significantly higher in both groups during the attacks than before the attacks (p < 0.05). There was a statistically significant decline in IL-6 levels both before and during FMF attacks, following eradication therapy in patients who cleared the infection (p < 0.05). In patients with homozygous M694V mutation, IL-6 levels before and during the FMF attacks were not significantly different in H. pylori-positive and -negative groups, despite a much lower level found in H. pylori-negative group (p > 0.05). Comparisons were not performed in other mutation groups because of small number of patients in each group. C-reactive protein (CRP) and fibrinogen levels were not significantly different between the groups (p > 0.05). We believe that the observation of IL-6 levels are lower both before and during FMF attacks both in H. pylori-negative patients and in patients who cleared the infection after eradication therapy is very important in the determination of the role of eradication of H. pylori on decreasing the frequency and severity of FMF attacks. As for today, the correlation between H. pylori infection and FMF seems unlikely; however, studies evaluating the interaction of cytokines in both diseases and their relations and roles will be needed to reach better conclusions.