Reference and point-of-care testing for G6PD deficiency: Blood disorder interference, contrived specimens, and fingerstick equivalence and precision

PLoS One. 2021 Sep 20;16(9):e0257560. doi: 10.1371/journal.pone.0257560. eCollection 2021.

Abstract

Certain clinical indications and treatments such as the use of rasburicase in cancer therapy and 8-aminoquinolines for Plasmodium vivax malaria treatment would benefit from a point-of-care test for glucose-6-phosphate dehydrogenase (G6PD) deficiency. Three studies were conducted to evaluate the performance of one such test: the STANDARD™ G6PD Test (SD BIOSENSOR, South Korea). First, biological interference on the test performance was evaluated in specimens with common blood disorders, including high white blood cell (WBC) counts. Second, the test precision on fingerstick specimens was evaluated against five individuals of each, deficient, intermediate, and normal G6PD activity status. Third, clinical performance of the test was evaluated at three point-of-care settings in the United States. The test performed equivalently to the reference assay in specimens with common blood disorders. High WBC count blood samples resulted in overestimation of G6PD activity in both the reference assay and the STANDARD G6PD Test. The STANDARD G6PD Test showed good precision on multiple fingerstick specimens from the same individual. The same G6PD threshold values (U/g Hb) were applied for a semiquantitative interpretation for fingerstick- and venous-derived results. The sensitivity/specificity values (95% confidence intervals) for the test for G6PD deficiency were 100 (92.3-100.0)/97 (95.2-98.2) and 100 (95.7-100.0)/97.4 (95.7-98.5) for venous and capillary specimens, respectively. The same values for females with intermediate (> 30% to ≤ 70%) G6PD activity were 94.1 (71.3-99.9)/88.2 (83.9-91.7) and 82.4 (56.6-96.2)/87.6(83.3-91.2) for venous and capillary specimens, respectively. The STANDARD G6PD Test enables point-of-care testing for G6PD deficiency.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Blood Specimen Collection
  • Child
  • Child, Preschool
  • Female
  • Glucosephosphate Dehydrogenase / blood*
  • Glucosephosphate Dehydrogenase / genetics
  • Glucosephosphate Dehydrogenase / standards
  • Glucosephosphate Dehydrogenase Deficiency / complications
  • Glucosephosphate Dehydrogenase Deficiency / diagnosis*
  • Hematologic Diseases / complications
  • Hemoglobins / analysis
  • Humans
  • Leukocyte Count
  • Male
  • Middle Aged
  • Point-of-Care Systems / standards*
  • Reagent Kits, Diagnostic
  • Reference Standards
  • Sensitivity and Specificity
  • Young Adult

Substances

  • Hemoglobins
  • Reagent Kits, Diagnostic
  • Glucosephosphate Dehydrogenase

Grants and funding

This work was funded in part by the United Kingdom’s Foreign, Commonwealth & Development Office (FCDO), grant number 204139. The work was supported, in part, by the Bill & Melinda Gates Foundation [OPP1107113]. Under the grant conditions of the Gates Foundation, a Creative Commons Attribution 4.0 Generic License has been assigned to the Author Accepted Manuscript version that might arise from this submission. The findings and conclusions contained within are those of the authors and do not necessarily reflect the positions of FCDO or the Gates Foundation. The FCDO and Bill & Melinda Gates Foundation awards to PATH support the availability of point-of-care tests for G6PD deficiency. Neither PATH, nor the co-authors have any financial interests in the commercial availability of any of the products discussed in this article. All authors read the journal’s authorship statement. All authors have read the journal’s policy on conflict of interest and do not have a conflict of interest to disclose.