title: Comparative study of Kaposi's sarcoma-associated herpesvirus serological assays using clinically and serologically defined reference standards and latent class analysis.
abstract: Accurate determination of infection with Kaposi's sarcoma-associated herpesvirus (KSHV) has been hindered by the lack of a "gold standard" for comparison of serological assays used to estimate KSHV prevalence in serosurveys conducted in different settings. We have evaluated the performance of five in-house (developed at University College London [UCL], United Kingdom, and at the virology laboratory of the Instituto de Medicine Tropical [IMT] in Sao Paulo, Brazil) and two commercial (ABI and DIAVIR) serological assays to detect antibodies to latency-associated nuclear antigen (LANA) and to lytic KSHV antigens. We used a variety of serum samples assembled to represent populations likely to be at high, intermediate, and low risk of KSHV infection in Brazil. Composite reference standard panels were prepared based on clinical and serological parameters, against which assay performances were assessed using conventional Bayesian statistics and latent class analysis (LCA). Against the clinical reference standard, in-house immunofluorescence assays to detect anti-LANA antibodies (IFA-LANA) produced at UCL and IMT had similar performances, with sensitivities of 61% (95% confidence interval [CI], 48% to 74%) and 72% (95% CI, 58% to 83%) and specificities of 99% (95% CI, 94% to 100%) and 100% (95% CI, 96% to 100%), respectively, and only the IMT IFA-LANA was included in LCA, together with the IMT IFA-lytic and four enzyme-linked immunosorbent assays (ELISAs). The LCA indicated that the IMT whole-virus ELISA performed best (sensitivity, 87% [95% CI, 81% to 91%]; and specificity, 100% [95% CI, 98% to 100%]), confirming the results obtained with the conventional statistical approach. Commercially available ELISA-based tests yielded the lowest specificities using a spectrum of serum samples. The evaluation of KSHV serological assays is warranted before planning serosurveys in various settings.
authors.affiliation: Clinical Research Unit, Department of Infectious & Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom. nascimentoc@iarc.fr
authors.forename: Maria Claudia
authors.initials: MC
authors.lastname: Nascimento
authors.forename: Vanda Akico
authors.initials: VA
authors.lastname: de Souza
authors.forename: Laura Masami
authors.initials: LM
authors.lastname: Sumita
authors.forename: Wilton
authors.initials: W
authors.lastname: Freire
authors.forename: Fernando
authors.initials: F
authors.lastname: Munoz
authors.forename: Joseph
authors.initials: J
authors.lastname: Kim
authors.forename: Claudio S
authors.initials: CS
authors.lastname: Pannuti
authors.forename: Philippe
authors.initials: P
authors.lastname: Mayaud
mesh_terms: D000914:Antibodies, Viral / Q000097:blood*; D000956:Antigens, Viral / Q000276:immunology*; D001938:Brazil; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay / Q000592:standards; D005455:Fluorescent Antibody Technique / Q000592:standards; D006566:Herpesviridae Infections / Q000175:diagnosis* / Q000276:immunology / Q000821:virology; D019288:Herpesvirus 8, Human / Q000276:immunology*; D006801:Humans; D007223:Infant; D008297:Male; D009687:Nuclear Proteins / Q000276:immunology*; D011933:Reagent Kits, Diagnostic / Q000592:standards; D012015:Reference Standards; D012514:Sarcoma, Kaposi / Q000175:diagnosis* / Q000276:immunology / Q000821:virology; D012680:Sensitivity and Specificity; D006113:United Kingdom; D017735:Virus Latency / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral; D009687:Nuclear Proteins; D011933:Reagent Kits, Diagnostic; C109540:latency-associated nuclear antigen