tokens: In the univariate models of either fixed or time dependent covariates , many variables were significantly associated with risk of progression to AIDS ( T4 cell count , T4 / T8 ratio , blastogenic responses to phytohemagglutinin , concanavalin A , and pokeweed mitogen , serum IgA , appearance of p24 antigen , and the development of oral hairy leukoplakia , thrush , or herpes zoster ) .