Cytochemical flow analysis of intracellular G6PD and aggregate analysis of mosaic G6PD expression

Eur J Haematol. 2018 Mar;100(3):294-303. doi: 10.1111/ejh.13013. Epub 2018 Jan 15.

Abstract

Background: Medicines that exert oxidative pressure on red blood cells (RBC) can cause severe hemolysis in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency. Due to X-chromosome inactivation, females heterozygous for G6PD with 1 allele encoding a G6PD-deficient protein and the other a normal protein produce 2 RBC populations each expressing exclusively 1 allele. The G6PD mosaic is not captured with routine G6PD tests.

Methods: An open-source software tool for G6PD cytofluorometric data interpretation is described. The tool interprets data in terms of % bright RBC, or cells with normal G6PD activity in specimens collected from 2 geographically and ethnically distinct populations, an African American cohort (USA) and a Karen and Burman ethnic cohort (Thailand) comprising 242 specimens including 89 heterozygous females.

Results: The tool allowed comparison of data across 2 laboratories and both populations. Hemizygous normal or deficient males and homozygous normal or deficient females cluster at narrow % bright cells with mean values of 96%, or 6% (males) and 97%, or 2% (females), respectively. Heterozygous females show a distribution of 10-85% bright cells and a mean of 50%. The distributions are associated with the severity of the G6PD mutation.

Conclusions: Consistent cytofluorometric G6PD analysis facilitates interlaboratory comparison of cellular G6PD profiles and contributes to understanding primaquine-associated hemolytic risk.

Keywords: Plasmodium vivax; G6PD deficiency; hemolytic anemia; lyonization; malaria.

Publication types

  • Multicenter Study

MeSH terms

  • African Americans
  • Alleles
  • Antimalarials / adverse effects*
  • Asian Continental Ancestry Group
  • Case-Control Studies
  • Contraindications, Drug
  • Erythrocytes / drug effects*
  • Erythrocytes / enzymology
  • Erythrocytes / pathology
  • Female
  • Flow Cytometry / methods
  • Gene Expression Regulation
  • Glucosephosphate Dehydrogenase / genetics*
  • Glucosephosphate Dehydrogenase / metabolism
  • Glucosephosphate Dehydrogenase Deficiency / enzymology
  • Glucosephosphate Dehydrogenase Deficiency / ethnology
  • Glucosephosphate Dehydrogenase Deficiency / genetics*
  • Glucosephosphate Dehydrogenase Deficiency / pathology
  • Hemizygote
  • Heterozygote
  • Humans
  • Male
  • Mosaicism*
  • Mutation*
  • Primaquine / adverse effects*
  • Severity of Illness Index
  • Software
  • Thailand
  • United States

Substances

  • Antimalarials
  • Glucosephosphate Dehydrogenase
  • Primaquine