Objective To comparatively analyze the immunological characteristics of patients with mild and severe influenza A (H1N1), and to provide the evidence for condition monitoring and treatment . Methods 52 cases with mild influenza A ( H1N1), 152 cases with severe influenza A ( H1N1) and 26 healthy subjects from July 1, 2009 to December 31, 2009 were enrolled in the study.Lymphocyte subsets in peripheral blood were analyzed by flow cytometry and the serum concentrations of interferon -γ( IFN-γ) and interleukin-4 (IL-4) were detected by enzyme-linked immune-sorbent assay (ELISA).Results The total lymphocyte counts were decreased obviously in patients with severe influenza A ( H1N1) than in mild pa-tients and in healthy subjects (P<0.01).The T lymphocyte, NK cells, CD4+T lymphocyte and CD8+T lym-phocyte were also decreased obviously in severe patients than in mild patients (P<0.01).The B lymphocyte and CD4+/CD8+were also decreased in severe patients than in mild patients but had no significant statistical difference (P=0.11, 0.175).The serum IFN-γlevels in patients with mild and severe influenza A (H1N1) were lower than those in control group, especially in patients with severe influenza A (H1N1) (compared with control group and mild group , P<0.01).And the changes of serum IL-4 levels were the same with the former, but there were no statistically significant differences in three groups (P>0.05).Con-clusion Immune dysfunction in patients with influenza A (H1N1) infection is associated with the severity of disease, especially cellular immunity .Therefore, monitoring of the immune system is valuable for the diag-nosis of influenza A(H1N1) infection.

Objective:To investigate the pathological characteristics in chronic HBV infection patients with different upper limits of alanine aminotransferase (ALT) normal values and the influencing factors of liver tissue injury.Methods:The clinical data of 667 chronic HBV infection patients with ALT<40 U/L and HBV DNA loads >30 IU/mL who received liver biopsy in Zhenhai District Hospital of Traditional Chinese Medicine and Hwa Mei Hospital from January 2014 to December 2020 were retrospectively analyzed. The enrolled patients were divided into ALTⅠ group (<30 U/L for males, <19 U/L for females), ALTⅡ group (≥30 U/L and <35 U/L for males, ≥19 U/L and <25 U/L for females) and ALT Ⅲ group (≥35 U/L and <40 U/L for males, ≥25 U/L and <40 U/L for females). According to the degree of liver inflammation (G) and fibrosis stage (S), the enrolled patients were divided into non-significant damage group (G<2 and S<2) and significant damage group (≥G2 or/and ≥S2). Ridit analysis was used to compare the G/S composition ratio among three ALT groups, Logistic regression was used to analyze the risk factors of liver injury, the receiver operating characteristic curve (ROC) and the area under the curve (AUC) were used to analyze the optimal diagnostic threshold of ALT.Results:There were significant differences in the composition ratio of G and S among the three ALT groups( χ2=13.926 and 14.702, both P<0.001). The constituent ratios of significant liver pathological damage in the three groups of ALT levels were 26.05% (99/380), 32.03% (41/128) and 46.54% (74/159), respectively( χ2=21.596, P<0.001). Multivariate logistic regression analysis showed that high white/globulin ratio and PLT counts( OR=0.246 and 0.986, both P<0.001)were the protective factors for liver tissue injury; while negative HBcAg staining and elevated ALT and GGT levels ( OR=3.797, 1.053 and 1.013, P<0.001 or <0.05) were the risk factors of liver injury. ROC curve demonstrated the ALT threshold of liver tissue damage in male and female patients were 25.6 U/L and 25.5 U/L. Conclusions:In chronic HBV infection patients with normal ALT, with the increase of ALT level, the degree of liver tissue pathological damage may become more severe. The study demonstrates that it is necessary to lower the ALT threshold for protecting patients from liver tissue pathological damage.