title: Characterization of HIV-1-specific antibodies and HIV-1-crossreactive antibodies to platelets in HIV-1-infected haemophiliac patients.
abstract: Sera from HIV-1-infected haemophiliacs were examined for human immunodeficiency virus (HIV) specific antibodies and for platelet crossreactive antibodies. Using HIV sepharose 4B affinity columns for serum absorption, antibodies against various HIV antigens, including HIV lysate. HIV-p24 and HIV-gp120, were eluted either by low or by high pH buffer. The eluates were examined by ELISA for HIV specificity and by flow cytometry for platelet crossreactivity. Two types of HIV antibodies could be eluted, i.e. acid-sensitive and alkaline-sensitive antibodies. HIV antibodies were obtained in 26/29 acid eluates and in 25/29 of the alkaline eluates from HIV-lysate columns; 96% (25/26) of the acid-eluted antibodies were HIV-specific but 48% (12/ 25) of the alkaline-eluted antibodies also showed crossreactivity to platelets. Of the 20 alkaline-eluted HIV-p24 antibodies, 40% (8/20) reacted specifically with HIV-p24 and 60% (12/20) were platelet crossreactive. In contrast, of the alkaline-eluted HIV-gp120 antibodies (n=17), 88% (15/17) were HIV gp120-specific and only 12% (2/17) were platelet crossreactive. Western blot analysis of platelets demonstrated that the anti-p24 antibodies recognized three bands with approximate molecular weights of 72000 to 95000. 69% of the serum antiplatelet antibodies showed platelet glycoprotein IIbIIIa specificity. Anti-HIV antibodies could be eluted from platelets. Hence, platelet crossreactive antibodies in HIV infection are primarily alkaline-sensitive and are associated predominantly with HIV p24 antibody; these antibodies may play a role in the immune thrombocytopenia of HIV-infected haemophiliacs.
authors.affiliation: St Michael's Hospital, University of Toronto, Ontario, Canada.
authors.forename: W K
authors.initials: WK
authors.lastname: Chia
authors.forename: V
authors.initials: V
authors.lastname: Blanchette
authors.forename: M
authors.initials: M
authors.lastname: Mody
authors.forename: J F
authors.initials: JF
authors.lastname: Wright
authors.forename: J
authors.initials: J
authors.lastname: Freedman
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000276:immunology*; D000906:Antibodies / Q000032:analysis*; D000918:Antibody Specificity; D001792:Blood Platelets / Q000276:immunology*; D015153:Blotting, Western; D018791:CD4 Lymphocyte Count; D004797:Enzyme-Linked Immunosorbent Assay; D015483:HIV Antibodies / Q000032:analysis*; D015488:HIV Antigens / Q000032:analysis; D016655:HIV Core Protein p24 / Q000032:analysis; D006467:Hemophilia A / Q000276:immunology*; D006801:Humans; D013921:Thrombocytopenia / Q000276:immunology
chemical_list: D000906:Antibodies; D015483:HIV Antibodies; D015488:HIV Antigens; D016655:HIV Core Protein p24