Investigating Effects of Drug Therapy for HIV Infection by Double Compartments Cellular Automata Simulations

摘要

The progress of human immunodeficiency virus (HIV) infection typically follows a three phase pattern; the primary response phase, the clinical latency phase, and the final phase of onset of acquired immunodeficiency syndrome (AIDS). In order to test the efficiency of different protocols in drug therapy for HIV patients, it is important to have a realistic model which reliably simulates the course of the infection which exhibits two drastically different time scales, days and decades. The classical ordinary or partial differential equations have been found to be inadequate in coping with such extreme spread in time scales. In this paper, we employ a two-compartment Cellular Automata (CA) model to study the dynamics of drug therapy of HIV infection. The levels of healthy an infected CD~+T cells are tracked in both the lymph node and peripheral blood compartments coupled and updated simultaneously with each time step. The viral loads in the two compartments are also updated through a system of difference equations. Drug therapy is then simulated by incorporating its effects in the update rules of the CA model. By adjusting the rules to update the cells in the CA lattice, it becomes possible to study the efficacies of different treatment strategies or drugs of choice, as well as the repercussion of drug resistance over time.