Performance of ELISA and Western blot to detect antibodies against HSV-2 using dried blood spots

Abstract

Background and aims: Herpes simplex virus type 2 (HSV-2) is a sexually transmitted agent and is detected worldwide. HSV-2 is the main cause of genital ulcers and is diagnosed mainly with serological tests. The objective of current study was to evaluate the use of DBS samples to detect HSV-2 antibodies using commercial ELISA and Western blot tests.

Materials and methods: IgG-G2 ELISA (Human^® Diagnostics, Germany) and Western blot IgG/IgM (EUROLINE-WB, Euroimmun^® Germany) tests were modified to use DBS samples. Samples were processed by both methods to determine ELISA cutoff points using ROC curves. ELISA was performed with 100μl and the Western blot with 200μl of eluted DBS. A 1:5 dilution was used and the incubation times were increased for the Western blot.

Results: 908 DBS samples were processed and the following cutoff points were determined: negative (0-3.79), undetermined (3.8-4.6) and positive (≥4.61), with sensitivity and specificity close to 95%.

Conclusion: Modifications of the cutoff points of the ELISA test were obtained with technical adjustments done to detect HSV-2 antibodies by ELISA and Western blot using DBS samples.

Keywords: Dried blood spots; ELISA; Herpes simplex virus type 2; Western blot.