Urine leukotriene B4 in familial Mediterranean fever and other forms of right lower abdominal pain

Background: Acute right lower abdominal pain may present a diagnostic dilemma. Leukotrienes have been found to be elevated in familial Mediterranean fever (FMF), a disease manifesting with recurrent episodes of "acute abdomen." To determine whether urine leukotriene B4 (LTB4) may differentiate between an FMF attack and some other forms of acute right lower abdominal pain. Methods: The LTB4 level was determined, using a commercial enzyme-linked immunosorbent assay (ELISA), in urine samples obtained from 36 patients with acute (<24 hours) right lower abdominal pain presenting to the emergency department, and from 18 healthy volunteers. Results: Compared with the healthy control subjects, LTB4 was significantly higher in those who had FMF (12 patients, p < 0.03). In other forms of acute right lower abdominal pain, including appendicitis (eight patients), urologic disorders (eight patients), and nonspecific abdominal pain (eight patients), intermediate levels of LTB4 were observed, not significantly different from those of either FMF patients or healthy control subjects. Conclusions: In the samples tested, urine LTB4 levels were not instrumental in differentiating FMF from other acute right lower abdominal pain.