Abstract: OBJECTIVE: To investigate the expression of and interleukin-12(IL-12) and interferon-γ(IFN-γ) in relation to the pathology of damp-heat of spleen-stomach syndrome(DHSS) induced by Helicobacter pylori(H. pylori) infection.METHODS: In total, 114 individual gastric mucosal specimens including 83 DHSS, 19 spleen-qi deficiency syndrome(SQD) and 12 from healthy volunteers(CON) were collected by gastroscopy. To explore the relationship between the two syndromes and H. pylori infection, individual samples were tested using rapid urease and methylene blue tests. Hematoxylin and eosin stained sections were examined to grade for the degree of inflammation and inflammatory activity, and expression of IL-12 and IFN-γ was investigated by immunohistochemistry.RESULTS: Statistically significant differences in the degree of inflammation and inflammatory activity were observed between the groups of specimens:DHSS, SQD and CON(P < 0.05). Additionally, greater intestinal metaplasia(IM) and dysplasia were observed in the DHSS group, especially those with H.pylori infection. Expression of both IFN-γ and IL-12 was higher in DHSS samples infected with H. pylori than in uninfected samples and in the CON(P 0.05) groups. Intriguingly, in gastric specimens exhibiting IM and dysplasia, IL-12 translocated from the nucleus into the cytoplasm.CONCLUSION: Our findings suggest that IL-12 and IFN-γ are involved in DHSS pathology, but not in SQD, acting as healthy-Qi. DHSS is not just the consequence of those two cytokines but results from the cross-talk between a number of cytokines and/or other proteins, which may warrant further investigation in DHSS patients infected with H. pylori.

Key words: Helicobacter pylori, Interleukin-12, Interferon-gamma, Spleen stomach dampness heat, Spleen Qi deficiency