Precision of the Kalon Herpes Simplex Virus Type 2 IgG ELISA: an international inter-laboratory assessment

BMC Infect Dis. 2015 Sep 30:15:398. doi: 10.1186/s12879-015-1130-6.

Abstract

Background: The commercial Kalon HSV-2 IgG ELISA is currently recommended for research use in sub-Saharan Africa because of its superior accuracy compared to other serologic assays. However, there are no data on key precision parameters of Kalon such as inter-operator variation, repeatability, and reproducibility, thus contributing to a barrier for its acceptance and use in clinical trials in sub-Saharan Africa. We evaluated the analytical and field precision of the Kalon HSV-2 IgG ELISA.

Methods: A total of 600 HIV-infected and uninfected serum samples from South Africa and Zambia, previously tested by the gold standard University of Washington HSV western blot (UW-WB), were tested using Kalon by two technologists in an United States reference laboratory. Aliquots of 183 samples were retested using Kalon by an on-site technologist in a South African laboratory and a Zambian laboratory.

Results: Intra-assay variation was below 10 %. Intra-assay, intra-laboratory, and inter-laboratory correlation and agreement were significantly high (p < 0.01). In comparison to the UW-WB, accurate performance of Kalon was reproducible by each operator and laboratory. Receiver operating characteristic curve analysis indicated high selectivity of Kalon in the overall study population (area under the curve = 0.95, 95%CI = 0.92-0.97).

Discussion: Kalon is a robust assay with high precision and reproducibility. Accordingly, operator errorlikely does not contribute to the variability observed in Kalon's specificity throughout sera from sub-Saharan Africa.

Conclusions: In populations with optimal diagnostic accuracy, Kalon is a reliable stand-alone method for on-site HSV-2 IgG antibody detection.

Publication types

  • Evaluation Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Antibodies, Viral / blood*
  • Area Under Curve
  • Calibration
  • Enzyme-Linked Immunosorbent Assay* / standards
  • Female
  • HIV Infections / complications
  • Herpes Genitalis / complications
  • Herpes Genitalis / diagnosis*
  • Herpes Genitalis / virology
  • Herpesvirus 2, Human / immunology*
  • Humans
  • Immunoglobulin G / blood*
  • Laboratories / standards*
  • Male
  • ROC Curve
  • Reproducibility of Results
  • Sensitivity and Specificity

Substances

  • Antibodies, Viral
  • Immunoglobulin G