Rapid Multiplexed Immunoassay for Detection of Antibodies to Kaposi’s Sarcoma-Associated Herpesvirus

<div><p>Diagnosis of KSHV-infected individuals remains a challenge. KSHV prevalence is high in several populations with high prevalence of HIV, leading to increased risk of development of Kaposi’s sarcoma (KS). While current assays are reliable for detecting antibodies to KSHV, none are routinely utilized to identify individuals with KSHV infection and thus at increased risk for KS due to assay complexity, lack of access to testing, and cost, particularly in resource-limited settings. Here we describe the addition of KSHV proteins LANA and K8.1 to a previously evaluated HIV/co-infection multiplexed fluorescence immunoassay system. This study demonstrates assay performance by measuring antibody reactivity for KSHV and HIV-1 in a collection of clinical specimens from patients with biopsy-proven KS and sourced negative controls. The KSHV assay correctly identified 155 of 164 plasma samples from patients with biopsy-proven KS and 85 of 93 KSHV antibody (Ab)-negative samples for a sensitivity of 95.1% and specificity of 91.4%. Assay performance for HIV-1 detection was also assessed with 100% agreement with independently verified HIV-1 Ab-positive and Ab-negative samples. These results demonstrate good sensitivity and specificity for detection of antibody to KSHV antigens, and demonstrate the potential for multiplexed co-infection testing in resource-limited settings to identify those at increased risk for HIV-1-related complications.</p></div

Signal / Cutoff values for the KSHV antigens LANA and K8.1 in the MBio Array cartridge.

<p>“POS” indicates the Kaposi’s Sarcoma biopsy-positive samples. “NEG” indicates negative control sera as determined by KSHV ELISA. The box and whisker plots show the median, 10^th, 25^th, 75^th and 90^th percentiles. The circles show location of the 5^th and 95^th percentiles.</p

ROC curve for MBio assay, including individual antigens, LANA and K8.1 and maximum S/CO.

<p>ROC curve for MBio assay, including individual antigens, LANA and K8.1 and maximum S/CO.</p

Characteristics of Study Participants.

<p>Characteristics of Study Participants.</p

Multivariable-adjusted associations between clinical factors and MBio S/CO and ELISA O.D. levels.

<p>Multivariable-adjusted associations between clinical factors and MBio S/CO and ELISA O.D. levels.</p