Model-Based Analysis of CD4 + Lymphocyte Dynamics In HIV Infected Individuals

Abstract

The previously suggested mathematical model of CD4 + lymphocyte depletion in HIV infected individuals is analyzed and further developed. The model assumes that CD4 + lymphocyte depletion is caused by HIV products. Fairly good simulation of CD4 + lymphocyte dynamics is obtained, when limitation of HIV growth by specific cytotoxic T cells is included in the model. As it is probable that the substantial decrease of CD4 + lymphocytes in HIV infection activates a feedback mechanism increasing the influx of new CD4 + lymphocytes, this type of influx control mechanism is also included in the model. It is shown that the simulated CD4 + lymphocyte dynamics agree with the observed data, analogously as in the earlier considered case of the constant influx. Moreover, the depleting effect of HIV products on mature and/or immature CD4 + lymphocytes is analyzed by the model. Also, another modification of the model assuming that CD4 + lymphocyte depletion is due to their destruction by cytotoxic T cells specific for HIV antigens, gives simulation results comparable to those obtained by the original version of the model, where the mechanism of the depletion is not specified.