International Journal of Laboratory Hematology The Official journal of the International Society for Laboratory Hematology
LETTER TO THE EDITOR
INTERNAT IONAL JOURNAL OF LABORATO RY HEMATO LOGY
Letter to the Editor
Prevalence and molecular defect characterization of glucose-6-phosphate dehydrogenase deficiency in Brazilian blood donors Sir, Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an inherited enzymopathy, and it affects about 400 million people worldwide [1, 2]. Although the majority of G6PD-deficient individuals are asymptomatic, severe acute hemolytic anemia can appear at several levels after exposure to oxidative agents, depending on the G6PD variant [3]. The risk factors associated with the use of G6PD-deficient blood in transfusion remain controversial. However, G6PD-deficient blood may exert negative impacts on premature neonates or patients who need repeated transfusions [4]. Although previous studies have already described the epidemiological distribution of the G6PD deficiency in others regions from Brazil [5–9], the prevalence and molecular characterization of G6PD deficiency in healthy blood donors from north-east Brazil are still unknown. Here, we evaluate the prevalence of G6PD deficiency among healthy blood donors from Brazilian north-east and characterize molecularly their G6PD defects. Between August 2010 to November 2011, 802 male volunteer blood donors were randomly selected from the Hematology and Hemotherapy Foundation of Pernambuco transfusion center. For the entire cohort, the qualitative determination of G6PD activity was performed on whole blood using the methemoglobinemia reduction test, as previously described [10]. The principle of this test is based on the glucose–sodium nitrite capacity in reduce hemoglobin in methemoglobin. Briefly, after incubation time (3 h at 37°C), the result can be determined by visual reading, comparing the color of the samples test with reference samples. For those cases in which the enzymatic activity is considered normal, the methemoglobin turns back to hemoglobin helped by a co-factor (methylene blue). It must be stressed that the methemoglobinemia reduction test is not specific for G6PD deficiency, and may detect others causes of methemoglobinemia, which include enzymatic defects or in the presence of unstable hemoglobin. Molecularly, the
© 2015 John Wiley & Sons Ltd, Int. Jnl. Lab. Hem. 2015, 37, e109–e111
G6PD African A- variant (G202A) and G6PD Mediterranean B- variant (C563T) characterization was determined using polymerase chain reaction followed by restriction fragment length polymorphism analysis (PCR-RFLP) in all samples. Hematological parameters were measured using a Coulter STKS (Coulter Electronics, Hialeah, FL, USA). Baseline patient characteristics were descriptively reported, and statistical analysis was performed using SPSS Statistics 17.0 (IBM Corporation, Somers, NY, USA). P-value
LETTER TO THE EDITOR
INTERNAT IONAL JOURNAL OF LABORATO RY HEMATO LOGY
Letter to the Editor
Prevalence and molecular defect characterization of glucose-6-phosphate dehydrogenase deficiency in Brazilian blood donors Sir, Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an inherited enzymopathy, and it affects about 400 million people worldwide [1, 2]. Although the majority of G6PD-deficient individuals are asymptomatic, severe acute hemolytic anemia can appear at several levels after exposure to oxidative agents, depending on the G6PD variant [3]. The risk factors associated with the use of G6PD-deficient blood in transfusion remain controversial. However, G6PD-deficient blood may exert negative impacts on premature neonates or patients who need repeated transfusions [4]. Although previous studies have already described the epidemiological distribution of the G6PD deficiency in others regions from Brazil [5–9], the prevalence and molecular characterization of G6PD deficiency in healthy blood donors from north-east Brazil are still unknown. Here, we evaluate the prevalence of G6PD deficiency among healthy blood donors from Brazilian north-east and characterize molecularly their G6PD defects. Between August 2010 to November 2011, 802 male volunteer blood donors were randomly selected from the Hematology and Hemotherapy Foundation of Pernambuco transfusion center. For the entire cohort, the qualitative determination of G6PD activity was performed on whole blood using the methemoglobinemia reduction test, as previously described [10]. The principle of this test is based on the glucose–sodium nitrite capacity in reduce hemoglobin in methemoglobin. Briefly, after incubation time (3 h at 37°C), the result can be determined by visual reading, comparing the color of the samples test with reference samples. For those cases in which the enzymatic activity is considered normal, the methemoglobin turns back to hemoglobin helped by a co-factor (methylene blue). It must be stressed that the methemoglobinemia reduction test is not specific for G6PD deficiency, and may detect others causes of methemoglobinemia, which include enzymatic defects or in the presence of unstable hemoglobin. Molecularly, the
© 2015 John Wiley & Sons Ltd, Int. Jnl. Lab. Hem. 2015, 37, e109–e111
G6PD African A- variant (G202A) and G6PD Mediterranean B- variant (C563T) characterization was determined using polymerase chain reaction followed by restriction fragment length polymorphism analysis (PCR-RFLP) in all samples. Hematological parameters were measured using a Coulter STKS (Coulter Electronics, Hialeah, FL, USA). Baseline patient characteristics were descriptively reported, and statistical analysis was performed using SPSS Statistics 17.0 (IBM Corporation, Somers, NY, USA). P-value
