Recurrent fever of unknown etiology: failure to demonstrate association between fever and plasma unconjugated etiocholanolone.

A sensitive method for determination of plasma unconjugated etiocholanolone by double-isotope-derivative dilution has been described. The mean values for normal subjects was 0.038+/-0.003 (SEM) mug/100 ml.40 patients, 20 with familial Mediterranean fever and 20 with other diseases characterized by recurrent fever were studied. The over-all mean concentration of plasma unconjugated etiocholanolone for the patients (febrile or afebrile) was 0.101 +/-0.012 mug/100 ml, significantly above that of normals. Mean plasma values for the patients while they were febrile did not differ from the mean values when they were afebrile. It is suggested that the concentration of plasma unconjugated etiocholanolone is not related to fever in these patients.