title: Changes in immunoglobulin isotypes and immunoglobulin G (IgG) subclasses during highly active antiretroviral therapy: anti-p24 IgG1 closely parallels the biphasic decline in plasma viremia.
abstract: The effects of highly active antiretroviral therapy (HAART) on immunoglobulin isotypes and immunoglobulin G (IgG) subclasses were studied in 12 patients in early stages of HIV-1 infection. Blood samples were obtained at enrollment and 2, 4, 8, 12, 24, 48, and 120 weeks after initiation of HAART. Immunoglobulin concentrations were determined by nephelometry, and anti-p24-specific IgG and IgG1 levels were determined by an enzyme immunoassay. Overall time changes were analyzed in analysis of variance models. IgG and IgG1 levels showed a marked overall decline, whereas other immunoglobulin isotypes and IgG subclasses did not change significantly. Anti-p24-specific IgG1 levels decreased considerably and significantly more in virus isolation-negative patients than in virus isolation-positive patients, as defined according to the ability to isolate HIV-1 from their CD4+ T cells after initiation of therapy. Anti-p24 IgG levels showed a similar but overall weaker decline in the two groups. However, the anti-p24 IgG1 level followed the biphasic decline in plasma viremia more closely than the anti-p24 IgG level, with an initial sharp decline that leveled off with time. These findings suggest that the main reduction in immunoglobulin levels is caused by reduced HIV-1-specific antigen stimulation rather than a general reduction in immune activation. Using anti-p24 IgG1 as a parameter of response to the effect of HAART merits further investigation.
authors: Centre for Research in Virology, The Gade Institute, University of Bergen, Bergen, Norway. pal.voltersvik@vir.uib.no
authors: Pål
authors: P
authors: Voltersvik
authors: Grethe
authors: G
authors: Albrektsen
authors: Elling
authors: E
authors: Ulvestad
authors: Anne Ma
authors: AM
authors: Dyrhol-Riise
authors: Birger
authors: B
authors: Sørensen
authors: Birgitta
authors: B
authors: Asjö
mesh_terms: D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use; D023241:Antiretroviral Therapy, Highly Active; D018791:CD4 Lymphocyte Count; D005260:Female; D016655:HIV Core Protein p24 / Q000097:blood / Q000276:immunology*; D015658:HIV Infections / Q000188:drug therapy* / Q000276:immunology* / Q000821:virology; D015497:HIV-1 / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D007124:Immunoenzyme Techniques; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology*; D007132:Immunoglobulin Isotypes / Q000187:drug effects* / Q000276:immunology; D008297:Male; D009391:Nephelometry and Turbidimetry; D012367:RNA, Viral / Q000097:blood / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014766:Viremia / Q000188:drug therapy / Q000276:immunology
chemical_list: D019380:Anti-HIV Agents; D016655:HIV Core Protein p24; D007074:Immunoglobulin G; D007132:Immunoglobulin Isotypes; D012367:RNA, Viral