Complex dynamical behaviour in the interaction between HIV and the immune system

Abstract

This chapter discusses the complex dynamical behavior in the interaction between HIV and the immune system. Clinical, immunological, and epidemiological studies reveal great variability among patients in the rate at which individuals develop clinical manifestations of HIV-mediated disease, from the point of infection, or seroconversion. The average incubation period of AIDS appears to be approximately 7–8 years, but over this period, marked fluctuations occur in blood serum titers of HIV antigen-specific antibodies and HIV antigenaemia, both within and among individual patients. There is a consistent general pattern of change in antigen concentration and antibody titers as patients progress from seroconversion through a period with no overt disease to AIDS-related-complex, and finally to AIDS. Two major peaks in antigenaemia are detectable, one 10–40 weeks after seroconversion and the second during the manifestation of ARC and AIDS. Not only do the durations and magnitudes of the early and late peaks in antigenaemia vary from individual to individual, but there are also indications of irregular bursts of antigenaemia within the relatively long silent phase between the early and late peaks.