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

The case and controls were selected from two designated hospitals for SARS in Beijing and Tianjin. During the 2003 SARS epidemic, a total of 132 confirmed SARS patients were reported from these two hospitals, which derived from two completely unrelated super spread events (SSE). All of the patients had been hospitalized for treatment, from which we selected 115 confirmed SARS cases for the study. Three of the remaining patients died and the other 14 patients were unavailable for study, because of the inconvenience of revisiting. The diagnosis was made according to the criteria published by the Chinese Ministry of Public Health, and subsequently confirmed by antibody seroconversion and/or detectable SARS-CoV RNA in respiratory secretions. Two control groups were used, individuals with close contacts with SARS patients (control A) and healthy controls (control B). Control A group consists of 141 subjects who had close contacts with confirmed SARS patients but were not infected, according to criteria that was defined by the World Health Organization [19] . Among these individuals were 110 high-risk health care workers who had been treating SARS patients for a prolonged duration, and 31 individuals who had shared a meal, utensil, residence, ward, vehicle, etc., with SARS patients. Control B group included 155 healthy, unrelated Chinese blood donors, who had blood drawn during July 2001-October 2002. All controls were tested negative for IgG antibody against SARS-CoV prior to being included into the study. All subjects contributed 3ml anticoagulated blood after written informed consent was obtained. We also used a standard questionnaire to collect demographic information (including age, ethnicity, region of origin, marital status, living environment, education level et al). All subjects were confirmed as genetically unrelated through interviewing. The comorbidity conditions that might have effect on disease susceptibility, such as diabetes mellitus, heart disease, hypertension, asthma, tuberculosis, and malignancy, were traced by reviewing medical records and self reporting. The study protocol was approved by the ethical committee at the National Center for AIDS Prevention and Control.