MATHEMATICAL-MODELING OF CHEMOTHERAPY IN HIV-INFECTION

A mathematical model of CD4(+) lymphocyte depletion in HIV infection i s used to simulate and analyse the effect of AZT treatment. In most ca ses, permanent administration of AZT is observed to stop the CD4(+) ly mphocyte count decline and to stimulate their increase up to a new ste ady-state level, which depends on the intensity of AZT treatment, i.e. AZT dose. Temporary administration of AZT leads only to a temporary i ncrease in CD4(+) lymphocyte count. After the treatment is terminated, the count starts to decline again. However, the resulting prolongatio n of patient's survival exceeds the time interval of AZT administratio n. Interestingly, the survival prolongation is greater, if the treatme nt is started at five than at two years after the infection and there is no striking increase in survival time if a dose of AZT inhibiting 7 5% of HIV proliferation is used instead of a lower one inducing 25% in hibition only.