RANITIDINE POSTOPERATIVE INTERLEUKIN-6 INDUCED C-REACTIVE PROTEIN-SYNTHESIS

BACKGROUND: The mechanism of post-traumatic immunosuppression is still not known in detail. However, histamine released during trauma and ma jor surgery may play a significant role in the process. Previously, we showed that the histamine-2 receptor antagonist (H(2)RA), ranitidine, reduced trauma-induced suppression of certain immunological parameter s. STUDY DESIGN The effect of perioperative ranitidine on postoperativ e change in plasma interleukin-6 (IL-6) and serum C-reactive protein ( CRP) levels was assessed in 23 women undergoing elective abdominal hys terectomy: The patients were randomized to receive intravenous ranitid ine, 100 mg twice a day from skin incision, for two days, followed by oral ranitidine, 150 mg twice a day, for a further three days, or no r anitidine. Interleukin-6 and CRP were analyzed in plasma and serum, re spectively, drawn preoperatively and six, 24, 48, and 120 hours after skin incision. RESULTS: Routine blood analyses, clinical data (except age), duration of surgery, anesthesia, antibiotic prophylaxis, blood l oss, and perioperative blood transfusion were similar in the two group s. Interleukin-6 levels were significantly increased in all patients a nd without difference between the ranitidine-treated and non-ranitidin e-treated patients after six, 24, and 48 hours compared to preoperativ e levels, respectively. C-reactive protein levels were also significan tly increased in all patients after 24, 48, and 120 hours, respectivel y; however, at 48 hours, CRP was significantly reduced in ranitidine-t reated patients compared with non-ranitidine-treated patients (p=0.02) . CONCLUSIONS: These results suggest that histamine-2 receptor activat ion mechanisms may not be involved in postoperative IL-6 synthesis. Ho wever, the reduced CRP level in ranitidine-treated patients suggests t hat H(2)RAs modulate IL-6 signal transduction in hepatic cells.