IL-12 RB1 Genetic Variants Contribute to Human Susceptibility to Severe Acute Respiratory Syndrome Infection among Chinese

Tang, Fang; Liu, Wei; Zhang, Fang; Xin, Zhong-Tao; Wei, Mao-Ti; Zhang, Pan-He; Yang, Hong; Ly, Hinh; Cao, Wu-Chun

In one previous study, marked elevation of IL-12 in plasma of SARS patients had been observed for at least 2 weeks after disease onset [27] , Since IL-12 can induce the production of IFN-c and other Th1 cytokines with suppression of the Th2 pathway [28, 29] .the observed early elevation of IL-12 could be causative of the SARS-CoV-induced activation of Th1 cells and NK cells, release of chemokines such as IL-8, and results in pulmonary inflammation [30] . One could then hypothesize that decreased IL-12R activity might predispose to infection but protect from severe disease manifestations. However, the data presented here appear to suggest that IL-12R activity is required for protection from severe disease, although the association between genetic polymorphisms and severe disease was no longer significant after multiple test correction was applied to the analysis. Therefore the actual role of IL12 in the protection from or susceptibility to severe disease still need more evidence from animal experiments.