Effect of Helicobacter pylori eradication on serum ammonia levels in patients with chronic liver disease.

ABSTRACT

BACKGROUND: Helicobacter pylori infection has been implicated in the development of encephalopathy in chronic liver disease (CLD); this is possibly due to increased production of ammonia by the action of bacterial urease on urea in the gastric lumen. AIM: To evaluate whether H. pylori eradication in patients with CLD affects arterial ammonia levels. METHODS: Forty-six patients with CLD (40 alcoholic, 6 post hepatitis B; Child's class A 7, B 17, C 22) and 36 patients with symptoms of acid-peptic disease (APD) underwent gastrointestinal endoscopy and biopsy; gastric biopsies were evaluated for H. pylori status using rapid urease test and histology. H. pylori-positive subjects received quadruple-drug eradication therapy for 2 weeks. Fasting arterial plasma ammonia levels were estimated before and after eradication of H. pylori. RESULTS: H. pylori infection was present in 21 of 46 (45.7%) patients with CLD and 23 of 36 (63.9%) with APD. At baseline, mean (SD) ammonia levels were higher in the CLD group (97.4 [10.9] versus 81.3 [7.7] mcg/dL in the APD group; p = 0.0001), irrespective of H. pylori status. Amongst patients with liver disease, arterial ammonia levels were similar in the H. pylori-positive and -negative patients (94.1 [9.7] and 100.2 [11.3] mcg/dL, respectively); however, ammonia levels were higher in patients in Child's class C (102.7 [11.4] mcg/dL/dL) than in those in class A (88.4 [1.6] mcg/dL; p < 0.002) or B (94.1 [9.7] mcg/dL; p < 0.002). In patients with APD, ammonia levels were higher in H. pylori-positive patients (85.3 [6.4] versus 74.1 [3.3] mcg/dL; p < 0.001). After eradication of H. pylori infection, ammonia levels decreased to 88.4 (10.0) mcg/dL in CLD and 76.7 (4.8) mcg/dL in APD (p = 0.001 as compared to baseline). There was no difference in post-eradication ammonia levels between Child's classes. CONCLUSION: Levels of arterial blood ammonia are higher in CLD than in APD, and correlate with severity of liver disease. H. pylori eradication was associated with reduction in arterial ammonia levels in patients with CLD.