  Following previous models describing a quasi steady state (QSS) for the
evolution of HIV infection and AIDS, we have developed a larger formalism
simulating the long-term evolution of the QSS We show that the long-term
evolution of AIDS cannot be explained by the destruction alone of CD4 T cells,
either directly or indirectly. The destruction of CD4 T cells can lead only to
a QSS with a lower concentration of CD4 T cells, but CD4 destruction cannot
generate the sustained long-term decrease in T cells leading to AIDS. We here
suggest some workable explanations.
