For the risk factor analysis, age, symptoms (fever, fatigue, asthma, cough, anorexia), physical and chemical indexes (cystatin C, HDL, count of WBC, neutrophil count, creatinine, total bilirubin, lymphocyte percentage, monocyte count, albumin, total bile acid, hematocrit (35–45), neutrophil percentage>75, prealbumin<150, Lymphocyte percentage<20, total bile acid<20, Lymphocyte count<1.1 and glucose) were associated with severe cases in univariable analysis (Table 4). This evidence concerns the gene TTR and Anorexia.