Comparison Of Viral Trajectories In Aids Studies By Using Nonparametric Mixed-Effects Models

The efficacy of antiretroviral therapies for human immunodeficiency virus (HIV) infection can be assessed by studying the trajectory of the changing viral load with treatment time, but estimation of viral trajectory parameters by using the implicit function form of linear and nonlinear parametric models can be problematic. Using longitudinal viral load data from a clinical study of HIV-infected patients in Taiwan, we described the viral trajectories by applying a nonparametric mixed-effects model. We were then able to compare the efficacies of highly active antiretroviral therapy (HAART) and conventional therapy by using Young and Bowman’s (1995) test

B 型肝炎病毒感染與愛滋病毒感染之關係

The Multicenter AIDS Cohort Study (MACS) was designed to study the natural history of human immunodeficiency virus type 1 (HIV-1) infection, including the relationship between hepatitis B virus (HBV) and HIV-1 infection. In total, 4954 homosexual men were recruited from April 1984 through March 1985 and have been followed up thereafter every 6 months. Hepatitis B surface antigen and hepatitis B core antibody were tested for at the first visit by RIA or EIA; HIV-1 antibody testing was done at each visit by ELISA and confirmed by Western blot assay. The role of HBV infection in HIV-1 seroconversion was studied by stratification for sexual behavior and disease visit by visit. The adjusted risk ratio was 2.02 for hepatitis B surface antigen carriers and 2.14 for hepatitis-immune cases compared with hepatitis -susceptible subjects. Similar results were obtained using a logistic regression model. After taking into account changes in sexual behavior and disease over time, the authors conclude that past HBV infection remains suspect as a cofactor or as a surrogate for other factors associated with HIV-1 seroconversion. #B019300