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.
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.
de Souza
Vanda Akico Ueda Fick
VA
Laboratory of Virology (LIM52), Instituto de Medicina Tropical de São Paulo, Universidade de São Paulo, São Paulo, Brazil. vaueda@usp.br
Pierrotti
Ligia Camera
LC
Sumita
Laura Masami
LM
Freire
Wilton Santos
WS
Segurado
Aluisio Augusto Cotrim
AA
Pannuti
Cláudio Sérgio
CS
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
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)