Cut-off values for diagnosis of G6PD deficiency by flow cytometry in Thai population
Issued Date
2022-10-01
Resource Type
ISSN
09395555
eISSN
14320584
Scopus ID
2-s2.0-85134347666
Pubmed ID
35840819
Journal Title
Annals of Hematology
Volume
101
Issue
10
Start Page
2149
End Page
2157
Rights Holder(s)
SCOPUS
Bibliographic Citation
Annals of Hematology Vol.101 No.10 (2022) , 2149-2157
Suggested Citation
Thedsawad A., Wanachiwanawin W., Taka O., Hantaweepant C. Cut-off values for diagnosis of G6PD deficiency by flow cytometry in Thai population. Annals of Hematology Vol.101 No.10 (2022) , 2149-2157. 2157. doi:10.1007/s00277-022-04923-7 Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/87235
Title
Cut-off values for diagnosis of G6PD deficiency by flow cytometry in Thai population
Author(s)
Author's Affiliation
Other Contributor(s)
Abstract
In heterozygous females, X-inactivation causes a change in glucose-6-phosphate dehydrogenase (G6PD) activity from normal to deficient. Most G6PD screening tests are used to accurately diagnose hemizygous males, but they are less reliable for diagnosing heterozygous females. This study established flow cytometric cut-off values for screening of G6PD deficiency in hemizygous males and heterozygous or homozygous females. We studied 205 (125 females, 80 males) leftover blood samples from quantitative methemoglobin reduction (MR) screening. G6PD gene mutations determined by multiplex amplification refractory mutation system-polymerase chain reaction and direct DNA sequencing were used as the gold standard reference. Accuracy of the test, including the sensitivity, specificity, and positive and negative predictive values, was analyzed using MedCalc software. The optimal cut-off values for classification of %red blood cells with normal G6PD activity or %bright cells into homozygous normal, heterozygous, and homozygous deficiency in females were 85.4–100%, 6.3–85.3%, and 0–6.2%, respectively (sensitivity 93.2%, specificity 100%). The cut-offs for classification into hemizygous normal and hemizygous deficiency in males were 76.5–100% and 0–76.4%, respectively (sensitivity 100%, specificity 96.5%). Flow cytometry can be used to differentiate heterozygous females with intermediate phenotype from homozygous females, but cannot distinguish between heterozygous females with extreme phenotype and homozygous females. By flow cytometry, heterozygous and homozygous deficiency was detected in 29.6% and 3.2% of females, respectively. Among males, hemizygous deficiency was found in 31.3%. Flow cytometry can be used to screen patients with G6PD deficiency, and reliably and efficiently identify heterozygous and homozygous females, and hemizygous males based on cellular G6PD activity.