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

Patel EU, Manucci J, Kahle EM, Lingappa JR, Morrow RA, Piwowar-Manning E, James A, Maluzi KF, Cheeba MM, Gray G, Delany-Moretlwe S, Inambao M, Vwalika B, Quinn TC, Laeyendecker O - BMC Infect. Dis. (2015)

Bottom Line: Intra-assay, intra-laboratory, and inter-laboratory correlation and agreement were significantly high (p < 0.01).Accordingly, operator errorlikely does not contribute to the variability observed in Kalon's specificity throughout sera from sub-Saharan Africa.In populations with optimal diagnostic accuracy, Kalon is a reliable stand-alone method for on-site HSV-2 IgG antibody detection.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Immunoregulation, Division of Intramural Research, NIAID, NIH, Baltimore, MD, USA. epatel6@jhmi.edu.

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.

No MeSH data available.


The intermediate precision of the Kalon HSV-2 IgG ELISA (N = 596). These data are based on the performance of Kalon by Technologist-Jr. and Technologist-Sr. at the HPTN Laboratory Center in the USA. a Shows box plots that represent the range, interquartile range, and median Kalon index values for all samples tested by both operators. b Shows the correlation and variability in Kalon index values between operators. c Presents the agreement of categorical results between operators as determined by the manufacturer’s index cut-offs (<0.9, negative; 0.9–1.1, indeterminate; >1.1 positive)
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Fig1: The intermediate precision of the Kalon HSV-2 IgG ELISA (N = 596). These data are based on the performance of Kalon by Technologist-Jr. and Technologist-Sr. at the HPTN Laboratory Center in the USA. a Shows box plots that represent the range, interquartile range, and median Kalon index values for all samples tested by both operators. b Shows the correlation and variability in Kalon index values between operators. c Presents the agreement of categorical results between operators as determined by the manufacturer’s index cut-offs (<0.9, negative; 0.9–1.1, indeterminate; >1.1 positive)

Mentions: Figure 1 depicts the intra-laboratory repeatability of Kalon for all samples tested at the HPTN Laboratory Center. Kalon index values for samples run by Technologist-Jr. (median = 2.48; IQR = 0.42–5.34) and Technologist-Sr. (median = 2.42; IQR = 0.49–5.48) at the HPTN Laboratory Center were not significantly different (P = 0.567; Fig. 1a). The sample Kalon index values between both operators had an average CV of 12.8 % and were significantly correlated (P < 0.01; Fig. 1b). There was ‘almost perfect’ inter-operator agreement between operators within the HPTN Laboratory Center (κ = 0.90; n = 596; Fig. 1c).Fig. 1


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

Patel EU, Manucci J, Kahle EM, Lingappa JR, Morrow RA, Piwowar-Manning E, James A, Maluzi KF, Cheeba MM, Gray G, Delany-Moretlwe S, Inambao M, Vwalika B, Quinn TC, Laeyendecker O - BMC Infect. Dis. (2015)

The intermediate precision of the Kalon HSV-2 IgG ELISA (N = 596). These data are based on the performance of Kalon by Technologist-Jr. and Technologist-Sr. at the HPTN Laboratory Center in the USA. a Shows box plots that represent the range, interquartile range, and median Kalon index values for all samples tested by both operators. b Shows the correlation and variability in Kalon index values between operators. c Presents the agreement of categorical results between operators as determined by the manufacturer’s index cut-offs (<0.9, negative; 0.9–1.1, indeterminate; >1.1 positive)
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4591065&req=5

Fig1: The intermediate precision of the Kalon HSV-2 IgG ELISA (N = 596). These data are based on the performance of Kalon by Technologist-Jr. and Technologist-Sr. at the HPTN Laboratory Center in the USA. a Shows box plots that represent the range, interquartile range, and median Kalon index values for all samples tested by both operators. b Shows the correlation and variability in Kalon index values between operators. c Presents the agreement of categorical results between operators as determined by the manufacturer’s index cut-offs (<0.9, negative; 0.9–1.1, indeterminate; >1.1 positive)
Mentions: Figure 1 depicts the intra-laboratory repeatability of Kalon for all samples tested at the HPTN Laboratory Center. Kalon index values for samples run by Technologist-Jr. (median = 2.48; IQR = 0.42–5.34) and Technologist-Sr. (median = 2.42; IQR = 0.49–5.48) at the HPTN Laboratory Center were not significantly different (P = 0.567; Fig. 1a). The sample Kalon index values between both operators had an average CV of 12.8 % and were significantly correlated (P < 0.01; Fig. 1b). There was ‘almost perfect’ inter-operator agreement between operators within the HPTN Laboratory Center (κ = 0.90; n = 596; Fig. 1c).Fig. 1

Bottom Line: Intra-assay, intra-laboratory, and inter-laboratory correlation and agreement were significantly high (p < 0.01).Accordingly, operator errorlikely does not contribute to the variability observed in Kalon's specificity throughout sera from sub-Saharan Africa.In populations with optimal diagnostic accuracy, Kalon is a reliable stand-alone method for on-site HSV-2 IgG antibody detection.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Immunoregulation, Division of Intramural Research, NIAID, NIH, Baltimore, MD, USA. epatel6@jhmi.edu.

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.

No MeSH data available.