TABLE 2.
Performance of KSHV serological assays in comparison with a clinically defined reference standard (panel A) and composite reference standard (panel B)
| Standard panel (n) and KSHV serological assay | No. of positive samples/no. of samples tested (%) | % Sensitivity (95% CI) | % Specificity (95% CI) |
|---|---|---|---|
| A (162)a | |||
| UCL IFA-LANA | 36/154 (23) | 61 (48-74) | 99 (94-100) |
| IMT IFA- LANA | 41/162 (25) | 72 (58-83) | 100 (96-100) |
| B (393)b | |||
| In-house assays | |||
| IFA-lytic | 106/392 (27) | 85 (77-92) | 92 (88-95) |
| IMT whole-virus ELISA | 170/375 (45) | 97 (91-99) | 72 (66-77) |
| MAP ELISA (ORFs K8.1 and 73) | 151/393 (38) | 95 (88-98) | 80 (75-84) |
| Commercial assays | |||
| ABI ELISA (whole virus) | 191/369 (52) | 99 (94-100) | 65 (59-70) |
| DIAVIR (ORFs K8.1 and 65) | 181/376 (48) | 94 (87-98) | 67 (61-72) |
AIDS-KS patients (group 1), representing “likely infected” patients, and children (group 7), representing “likely uninfected” patients, as a clinical reference. Panel A was used as a reference standard for comparison of IFA-LANA tests because AIDS-KS patients and children from areas where KSHV infection is not endemic have previously been established as reference groups for assessing IFA-LANA performance (16).
CRS, based on concordant results of the IMT and UCL IFA-LANA tests on the entire panel to derive “likely positive” and “likely negative” serological reference groups. To expand the spectrum of disease in the validation group, a CRS was formed using the concordant results of the IMT and UCL IFA-LANA tests for the entire panel.