OBJECTIVETo investigate the relation between serum level of interleukin-8 (IL-8), nitrogen monoxide (NO) and Helicobacter pylori (HP) infection, as well as the possible molecular mechanism of HP infection causing the imbalance of apoptosis and proliferation in gastric epithelial cells, which may lead to oncogenesis in stomach.

METHODSSerum IL-8 level was detected with enzyme-linked immunosorbent assay (ELISA). Serum NO was detected with chrome reduction method using plated copper.

RESULTSSerum level of IL-8 were 22.50 +/- 1.87 pg/ml in the normal tissue, 34.99 +/- 7.89 pg/ml in superficial gastritis, 65.27 +/- 10.60 pg/ml in atrophic gastritis and 94.84 +/- 11.09 pg/ml in gastric cancer (P < 0.01). Serum level of NO in the atrophic gastritis group (39.93 +/- 5.43 micromol/L) was significantly higher than that in the gastric cancer group (37.02 +/- 4.13 micromol/L) (P < 0.05). The differences in the other groups were not significant. IL-8 and NO levels in the HP(+) group were significantly higher than those in the HP(-) group (77.30 +/- 20.92 pg/ml vs 39.16 +/- 14.40 pg/ml, P < 0.01; 39.77 +/- 5.57 micromol/L vs 35.35 +/- 5.24 micromol/L, P < 0.01). Serum levels of IL-8 and NO in the cytotoxin-associated gene A protein (CagA)(+)HP group were significantly higher than those in the CagA(-)HP group (83.45 +/- 16.92 pg/ml vs 66.24 +/- 23.21 pg/ml, P < 0.01; 40.97 +/- 4.59 micromol/L vs 37.62 +/- 6.58 micromol/L, P < 0.05). Serum levels of IL-8 and NO showed positive correlation between superficial gastritis and atrophic gastritis groups (r = 0.881, r = 0.995), whereas no correlation was found in the normal or gastric cancer groups.

CONCLUSIONSerum levels of IL-8 and NO are correlated with CagA(+)HP strain infection. Combined detection of serum level of IL-8, NO and HP-CagA will contribute to the early diagnosis of precancerous lesion in the stomach.