Early hematologic changes in rhesus macaques (Macaca mulatta) infected with pathogenic and nonpathogenic isolates of SIVmac.

Early hematologic changes were studied over a 14 day period in three groups of six rhesus macaques intravenously infected with pathogenic and nonpathogenic isolates of SIVmac. Abnormalities in blood included a mild blood loss anemia, sporadic lymphopenia, and variable CD4+ and CD8+ T lymphocyte numbers. Prominent bone marrow findings in macaques inoculated with pathogenic uncloned SIVmac and molecularly cloned pathogenic SIVmac-239 were hypercellularity, myeloid and megakaryocytic hyperplasia, and lymphoid aggregates. Infrequent mild morphologic abnormalities were present in macaques infected with a nonpathogenic molecular clone, SIVmac-1A11.