title: Thrombocytopenia is strongly associated with simian AIDS in pigtail macaques.
abstract: Simian AIDS has a variable time course and presentation making it difficult to define disease effects of progressive simian immunodeficiency virus (SIV) infection. We commonly observed thrombocytopenia (TCP) associated with progressive SIV infection of pigtail macaques (Macaca nemestrina). We therefore analyzed the relationship between platelet counts, viral load (VL), and CD4 T-cell levels in 44 unselected macaques with chronic SIV infection. Persistent TCP was observed in 70% of pigtail macaques infected with SIVmac251 for up to 77 weeks in the absence of clinically significant bleeding. The presence of TCP correlated with higher SIV plasma VLs and depressed total and memory CD4 T cells. TCP was more common in macaques requiring euthanasia for incipient AIDS than macaques that survived to the end of the studies, although VL and CD4 T-cell decline were stronger independent predictors of AIDS-free survival. There was however no clear correlation between the development of TCP and immune activation as measured by plasma soluble CD14. We conclude that TCP is a useful end point to analyze SIV studies in pigtail macaques.
authors.affiliation: Department of Microbiology and Immunology, University of Melbourne, Melbourne, Australia.
authors.forename: Sheilajen
authors.initials: S
authors.lastname: Alcantara
authors.forename: Jeanette
authors.initials: J
authors.lastname: Reece
authors.forename: Thakshila
authors.initials: T
authors.lastname: Amarasena
authors.forename: Robert De
authors.initials: RD
authors.lastname: Rose
authors.forename: Joe
authors.initials: J
authors.lastname: Manitta
authors.forename: Janiki
authors.initials: J
authors.lastname: Amin
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Kent
mesh_terms: D000818:Animals; D018791:CD4 Lymphocyte Count; D018950:Lipopolysaccharide Receptors / Q000097:blood; D008254:Macaca nemestrina; D016097:Simian Acquired Immunodeficiency Syndrome / Q000150:complications*; D013921:Thrombocytopenia / Q000209:etiology*; D019562:Viral Load
chemical_list: D018950:Lipopolysaccharide Receptors