title: Seroreactivity to Kaposi's sarcoma-associated herpesvirus (human herpesvirus 8) latent nuclear antigen in AIDS-associated Kaposi's sarcoma patients depends on CD4+ T-cell count.
abstract: In AIDS/Kaposi's sarcoma (KS) patients, the sensitivity of immunofluorescence assays for detecting antibodies against latent nuclear antigen ranges from 52% to 93%. However, in classic and African KS, sensitivities above 90% have been reported systematically. This study evaluates whether CD4+ T-cell count affects seroreactivity to KSHV LANA and to lytic antigens in AIDS/KS patients. Kaposi's sarcoma-associated herpesvirus (KSHV) latent (IFA-LANA) and lytic (IFA-Lytic and ORF65/K8.1 EIA) antibodies were screened in 184 consecutive samples taken from 36 AIDS/KS patients grouped according to their CD4+ counts as follows: <100 (group A), 100-300 (group B), and >300 (group C) cells/mm(3). At enrollment, the immunofluorescence assay for the detection of antibodies against latent nuclear antigen (IFA-LANA) was positive in 3/11(27.2%) group A patients, in 10/11 (90.9%) group B patients, and in 14/14 (100%) group C patients (P < 0.01). Seropositivity to lytic antigens did not differ according to CD4+ T-cell count. Considering IFA-Lytic and ORF65/K8.1 EIA, seropositivity for lytic antigens was 100% in all three patient groups. In patients whose CD4+ count improved during follow-up, IFA-LANA seroconversion occurred; unstable counts resulted in a decrease in LANA antibody titers while the persistence of high counts resulted in unchanged, elevated antibody titers. In conclusion, LANA seroreactivity in AIDS/KS patients, as assessed by an immunofluorescence assay, depends on CD4+ T-cell count, rendering this evaluation important in the interpretation of seroepidemiological studies of KSHV infection in AIDS patients. To evaluate future serological tests based on latency-associated antigens, the selection of sera from KS patients with CD4+ cell count >300 cells/mm(3) as a positive gold standard is recommended.
authors: Laboratory of Virology (LIM52), Instituto de Medicina Tropical de São Paulo, Universidade de São Paulo, São Paulo, Brazil. vaueda@usp.br
authors: Vanda Akico Ueda Fick
authors: VA
authors: de Souza
authors: Ligia Camera
authors: LC
authors: Pierrotti
authors: Laura Masami
authors: LM
authors: Sumita
authors: Wilton Santos
authors: WS
authors: Freire
authors: Aluisio Augusto Cotrim
authors: AA
authors: Segurado
authors: Cláudio Sérgio
authors: CS
authors: Pannuti
mesh_terms: D017088:AIDS-Related Opportunistic Infections / Q000097:blood* / Q000276:immunology*; D000328:Adult; D000914:Antibodies, Viral / Q000097:blood*; D000956:Antigens, Viral / Q000276:immunology; D050976:Basic-Leucine Zipper Transcription Factors / Q000276:immunology; D015415:Biomarkers / Q000097:blood; D018791:CD4 Lymphocyte Count; D045744:Cell Line, Tumor; D005260:Female; D005455:Fluorescent Antibody Technique; D006023:Glycoproteins / Q000276:immunology; D006678:HIV; D019288:Herpesvirus 8, Human / Q000276:immunology*; D006801:Humans; D008297:Male; D009687:Nuclear Proteins / Q000276:immunology*; D010750:Phosphoproteins / Q000276:immunology*; D012097:Repressor Proteins / Q000276:immunology; D012514:Sarcoma, Kaposi / Q000097:blood* / Q000276:immunology*; D014764:Viral Proteins / Q000276:immunology
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral; D050976:Basic-Leucine Zipper Transcription Factors; D015415:Biomarkers; D006023:Glycoproteins; C118265:K8 protein, Human herpesvirus 8; C113454:K8.1 protein, Human herpesvirus 8; D009687:Nuclear Proteins; C119019:ORF65 protein, human herpesvirus 8; D010750:Phosphoproteins; D012097:Repressor Proteins; D014764:Viral Proteins; C118485:latent nuclear antigen (LNA)