Home About us Editorial board Ahead of print Current issue Search Archives Submit article Instructions Subscribe Contacts Login 
  • Users Online:199
  • Home
  • Print this page
  • Email this page

 Table of Contents  
Year : 2017  |  Volume : 2  |  Issue : 2  |  Page : 137-142

Evaluation of glucose-6-phosphate dehydrogenase enzyme deficiency and methemoglobin concentration in blood donors in a Nigerian Tertiary hospital-based blood bank

1 Department of Haematology, College of Health Sciences, Nnamdi Azikiwe University, Nnewi, Anambra State, Nigeria
2 Department of Medical Laboratory Science, College of Health Sciences, Nnamdi Azikiwe University, Nnewi, Anambra State, Nigeria

Date of Web Publication11-Sep-2017

Correspondence Address:
John C Aneke
Department of Haematology, College of Health Sciences, Nnamdi Azikiwe University, Nnewi, Anambra State
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/GJTM.GJTM_21_17

Rights and Permissions

Background: Glucose-6-phosphate dehydrogenase (G6PD) enzyme deficiency and methemoglobinemia adversely impact on blood transfusion safety by significantly increasing blood storage lesion. Objective: To determine G6PD enzyme deficiency and methemoglobin levels among blood donors in a tertiary hospital-based blood bank in Nigeria. Subjects and Methods: One hundred blood donors who met the criteria for blood donation were prospectively studied. Two milliliters of venous blood was collected from each participant into potassium-ethylenediaminetetraacetic acid specimen containers and analyzed for G6PD status and methemoglobin levels by spectrophotometry, on the same day of sample collection. Results: Among the donors, 43% had normal G6PD activity (9.32 ± 2.26 U/gHb), 44% had partially enzyme deficiency (4.92 ± 1.33 U/gHb), while 13% had total deficiency (0.47 ± 3.49 U/gHb); these were statistically different (P < 0.001). Methemoglobin concentration was elevated in 25% of study participants (3.05 ± 2.30%), while it was normal in 75% (0.99% ± 0.60%); these differences were statistically different (P < 0.001). Conclusion: A significant proportion of our blood donor set has G6PD enzyme deficiency (partial or total) as well as evidence of oxidation of hemoglobin; these findings have adverse implications on transfusion safety.

Keywords: Blood donors, oxidant injury, red cell enzyme, transfusion safety

How to cite this article:
Aneke JC, Ibeh NC, Okocha CE, Orakpor E. Evaluation of glucose-6-phosphate dehydrogenase enzyme deficiency and methemoglobin concentration in blood donors in a Nigerian Tertiary hospital-based blood bank. Glob J Transfus Med 2017;2:137-42

How to cite this URL:
Aneke JC, Ibeh NC, Okocha CE, Orakpor E. Evaluation of glucose-6-phosphate dehydrogenase enzyme deficiency and methemoglobin concentration in blood donors in a Nigerian Tertiary hospital-based blood bank. Glob J Transfus Med [serial online] 2017 [cited 2023 Mar 30];2:137-42. Available from: https://www.gjtmonline.com/text.asp?2017/2/2/137/214275

  Introduction Top

Blood transfusion is an important component of curative and preventive medicine and is equally a significant contributor to global health indices. It is crucial that adequate red cell survival (posttransfusion) is maintained, as this is of importance to good transfusion practices and optimal hematocrit recovery in transfusion recipients. Intracorpuscular defects in the red blood cell have been shown to be intimately linked with its survival and resistance to varying degrees of stress.[1]

Glucose-6-phosphate dehydrogenase (G6PD) is the most common human enzymopathy known globally, and in Sub-Saharan Africa, prevalence rate as high as 32.5% has been reported.[2] In addition to the high prevalence rates reported in Africa, G6PD deficiency has also been observed to affect individuals of Asian, Mediterranean, Middle-Eastern, and Latin American descents.[2],[3] Affected individuals are particularly prone to oxidative red cell damage, arising from their inability to protect red cells against oxidative stresses generated during normal body metabolism or following the ingestion of certain foods or drugs.[4]

Methemoglobin is a metalloprotein hemoglobin, which is formed following the oxidation of the iron in heme to the ferric state. Unlike hemoglobin, methemoglobin cannot adequately transport oxygen; therefore, marked tissue hypoxemia (functional anemia) could occur when it is present in the blood in high concentrations.[5]

In transfusion medicine, significant storage lesions could occur in the presence of intrinsic donor red cell defects and this could adversely impact on the quality of donor units and over all transfusion safety.[6] Blood donors who have high blood levels of methemoglobin or are negative for the G6PD enzyme are generally asymptomatic; consequently, these individuals are frequently missed during donor selection, leading to increase in donor units with potential to develop blood storage lesions.

In red cell exchange for neonatal hyperbilirubinemia, it has been observed that exchanges done with G6PD deficient red cells resulted in less effective clearance of serum bilirubin, due to exacerbated hemolysis which occurred postexchange.[7] Consequently, donor screening for G6PD deficiency is increasingly advocated for neonatal red cell exchange as well as in a number of other disease states which are pathogenetically linked with increased red cell destruction.[7]

There is a paucity of literature on the G6PD status and methemoglobin concentrations in potential blood donors in South-East Nigeria, despite the high general population prevalence of G6PD deficiency in the country. This study was therefore designed to evaluate the G6PD activity and methemoglobin levels in potential blood donors in a tertiary hospital-based blood bank in South-East Nigeria.

  Subjects and Methods Top

Study area

This study was carried out at the hematology and blood transfusion unit of Nnamdi Azikiwe University Teaching Hospital (NAUTH), Nnewi, Nnewi North Local Government Area, Anambra State, Nigeria. The NAUTH is a tertiary health-care facility serving the high-, low-, and middle-income populations of Nnewi and its environs. Nnewi is a commercial town, divided into four major villages, namely, Umudim, Uruagu, Nnewichi, and Otolo; the languages of communication in the town are Igbo and English.

Study design

This cross-sectional research is designed to study 100 prospective blood donors who presented at NAUTH Nnewi, Anambra State, Nigeria, and satisfied the criteria for blood donation. A convenient sampling method was employed until the sample size was achieved. Each participant had 2 ml of venous blood collected following standard protocols for venesection, into potassium ethylenediaminetetraacetic acid specimen containers, for the estimation of G6PD activity and blood methemoglobin concentration. All the samples were analyzed the same day of sample collection.

Study population

The sample population was 100 blood donors, both males and females within the age of 18 years to 60 years.

The sample size was calculated using the method described by Naing et al.:[8]

n = Z2P(1 − P)/d 2

(1.96)2(0.06)(1 − 0.06)/(0.05)2 = 86


n is the desired number of samples.

Z is the desired number of variation, usually set at 1.96 which corresponds to 95% confidence level.

P is the expected prevalence or proportion of attribute present in the population. The prevalence of G6PD deficiency in Nigeria ranges from 4% to 26%.[9]

d is the precision, usually set at 0.05.

Ethical consideration

The ethical clearance for this research was obtained from the NAUTH' Ethical Committee. Oral informed consent was obtained from the blood donors at the point of recruitment, according to the Helsinki declaration on researches that involve human subjects.

Inclusion and exclusion criteria

  • Inclusion criteria: All blood donors who satisfied the screening for blood donation
  • Exclusion criteria: Blood donors who are under specific medications such as antihypertensives (α-methyldopa) which could exacerbate red cell lysis and those known or suspected to have underlying hemoglobinopathy.

Sample analysis

The G6PD activity was determined following the protocol of Lohr and Waller,[10] which is based on the measurement in the rate of change of absorbance at 340 nm due to the reduction of oxidized nicotinamide adenine dinucleotide phosphate (NADP +). The test kits used were manufactured by RANDOX Laboratories ®; these have inbuilt sensitivity (minimum precision level) of 156 U/L and 98% accuracy.[11] The designation for normal enzyme activity was between 6.97 and 20.50 U/gHb.[11]

Blood methemoglobin concentration was estimated based on the method described by Lewis and Roper,[12] by adding 2 ml of 0.1 M phosphate buffer to 100 μl of whole blood followed by the addition of 250 ul of 4% potassium ferricyanide. The absorbance of the reaction mix was read spectrophotometrically after 10 min, at 630 nm wavelength. The classification of blood methemoglobin concentration (into high or low) was as follows: ≤2% is normal and ≥2% is high.[5]

RANDOX ® control samples were used during the testing for G6PD enzyme activity while pooled blood samples from apparently healthy controls were used to control the assay for blood methemoglobin levels.

Statistical analysis

Statistical Package for the Social Sciences (SPSS) version 21.0 (SPSS Inc., Chicago, IL, USA) was used for all data analyses. Results were expressed as means ± standard deviations while comparison of means was done using the Student's t-test and/or analysis of variance. The level of statistical significance was set at P < 0.05.

  Results Top

One hundred prospective blood donors were studied (aged 18–60 years); 39% of the donors were aged 18–25 years, 36% were 26–35 years, 11% were in the 36–45 years, while 14% were aged 46 years and above [Table 1]. The gender distribution of the study participants included 85% males and 15% females [Table 1].
Table 1: Demographic data of study participants

Click here to view

The ABO blood group distribution of the study participants included 70% (blood group O), 22% (blood group A), and 8% (blood group B) [Table 2].
Table 2: Blood group distribution of the study participants

Click here to view

The G6PD status of participants is shown in [Table 3]; 43 participants had normal enzyme activity (9.32 ± 2.26 U/gHb), 44 had partial deficiency (4.49 ± 1.33 U/gHb), while 13 had total deficiency (0.47 ± 3.49 U/gHb). These differences were statistically significant (P < 0.001).
Table 3: Glucose-6-phosphate dehydrogenase status of participants

Click here to view

Methemoglobin concentration was elevated in 25% of the participants (3.03% ± 2.30%), while 75% had normal blood level (0.99% ± 0.60%); these differences were statistically different (P < 0.001) [Table 4].
Table 4: Blood concentration of methemoglobin

Click here to view

There were no significant differences in G6PD enzyme status and blood methemoglobin concentration in study participants when compared to gender [Table 5], blood group, and age distribution (P > 0.05). The hemoglobin concentration of study subjects was significantly higher in subjects with G6PD enzyme deficiency compared with those with normal activity (P = 0.03; [Table 6]). There was no difference in enzyme activity when compared by blood group in study subjects [Table 7] and no significant correlation between G6PD enzyme status and blood methemoglobin level in all study participants (r = 0.34; P = 0.12).
Table 5: Comparison of glucose-6-phosphate dehydrogenase enzyme activity, hemoglobin concentration, and methemoglobin levels of participants by gender

Click here to view
Table 6: Comparison of methemoglobin levels and hemoglobin concentration by glucose-6-phospahate dehydrogenase enzyme status

Click here to view
Table 7: Comparison of glucose-6-phosphate dehydrogenase enzyme activity, hemoglobin concentration, and methemoglobin levels of study participants by with the ABO blood group

Click here to view

  Discussion Top

Donors within the 18–25 years age group had the highest representation in this study (39.0%) [Table 1]; this pattern of donor distribution is in agreement with the report of Bolarinwa et al. in Ile-Ife, South West Nigeria, and represents the most active age stratum of the population.[13]

The prevalence rate of G6PD deficiency is known to differ widely among different population groups, being dependent on racial/ethnic composition as well as other sociogeographical determinants. Indeed, the prevalence rates ranging from 3.4% in the Americas to 3.9%, 2.9%, 7.5%, 6.0%, and 4.7% in Europe, the Pacific, Sub-Saharan Africa, the Middle East, and Asia, respectively, have been reported.[14] In this study, the prevalence of total G6PD deficiency was 13% among our blood donor population [Table 2]; this is keeping with reports from other parts of Nigeria. In North Central Nigeria, Egesie et al. showed that 20% (26 out of 130) of blood donors had deficient G6PD enzyme activity, while in Osogbo, South West Nigeria, Akanni et al. reported the prevalence rate of 19.5%.[15],[16] The high prevalence of G6PD deficiency observed in this study (and in other studies from different parts of Nigeria) could be linked to the high prevalence of malaria infection. Individuals who are G6PD deficient have been shown to have significant survival advantage against severe forms of Plasmodium falciparum malaria; this is thought to be due to impaired maturation of malaria parasite in G6PD deficient red cells.[17]

The gender distribution of our study population showed that 12 (92.3%) of the G6PD deficient donors were males while 1 (7.7%) were females; additionally, 89.7% of all donors were males, while 10.3% were females. Similar (predominantly male) demographic patterns have been replicated in earlier studies in parts of Nigeria and Africa.[13],[16],[17],[18],[19],[20] The above observation is equally in keeping with the fact that G6PD deficiency is an X-linked disorder and so predominates in male participants.

In this study, even though blood group B donors showed the highest level of G6PD activity (6.99 ± 3.85 U/Hg) compared with others, this relationship was not statistically different. The above observations are in keeping with an earlier report which evaluated the G6PD activity of stored blood and emphasized that the different blood groups of study participants did not show any significant variation in their G6PD activity.[21]

Under normal physiologic conditions, blood methemoglobin levels are well regulated (<1%) by the action of the methemoglobin reductase enzyme system (mainly the NADH-cytochrome b5 reductase).[22] However, in a number of infectious and noninfectious conditions (including malaria parasitemia, ingestion of nitrate containing compounds, and certain drugs), the protective action of these enzyme systems could become overwhelmed, leading to acute increase in blood methemoglobin levels.[23] In this study, 25% of our donor set had elevated blood methemoglobin levels (3.05% ± 2.30%) compared with 75% who had normal blood levels (0.99% ± 0.60%); these differences were significantly different [P < 0.001; [Table 4]. Zama et al. in Sokoto, North-West Nigeria, and Okeke et al. in Nnewi, South East Nigeria, independently reported high prevalence rates of asymptomatic malaria infection in 2 donor populations (32.5% and 75.0%, respectively).[24],[25] These observations most probably account for the high blood methemoglobin levels observed in this study, as intracellular malaria parasites have been shown to possess the ability to spontaneously convert iron (Fe2+) to ferric (Fe3+) within food vacuoles.[5] Asymptomatic malaria infection of potential donors has therefore gained renewed significance in transfusion safety because increased blood levels of methemoglobin are known to be associated with various potentially fatal complications such as cyanosis, change in mental status, and even death.[5] This is because in the presence of G6PD deficiency, there is insufficient supply of NADPH for the NADPH-dependent methemoglobin reductase enzyme, which catalyzes the reduction of preformed methemoglobin to oxyhemoglobin.[26] This often results in exaggerated red cell destruction, especially in the presence of oxidant stress. Even though our study conditions did not involve the introduction of oxidant stress, it is likely that the increased loss of methemoglobin containing red cells (in response to oxidant challenge) in G6PD enzyme deficient donors could have accounted for the lack of significant difference in blood levels of methemoglobin of study participants, when compared with their G6PD enzyme status (P = 0.59) [Table 6]. The hemoglobin concentration of study participants was significantly higher in those with partial and total G6PD enzyme deficiency compared with those with normal activity (P = 0.03) [Table 6]; this may be related to the reticulocyte response which could accompany low-grade red cell lysis encountered in methemoglobinemia.[22]

  Conclusion Top

The high frequency of G6PD enzyme deficiency and elevated blood methemoglobin level observed in the donor set may indicate that a number of our donor units could have significant storage lesion and may be of limited usefulness in transfusions for neonatal hyperbilirubinemia, sickle cell disease (SCD), as well as in G6PD deficient recipients.


Consideration should be given to the routine screening of all donor units to be transfused to neonates (particularly for hyperbilirubinemia), SCD and G6PD negative recipients, for G6PD enzyme deficiency and methemoglobinemia. The CareStart G6PD Rapid Diagnostic Test (CSG; AccessBio, USA) is fast and can be properly adapted for use in routine blood bank testing. This could reduce the potential blood storage lesions that follow the collection of such units and improve transfusion safety. More research should be carried out on this study, with larger population of blood donors, to confirm these findings.

Limitation of the study

Malaria parasitemia was not accessed in this study, particularly in donors with high blood methemoglobin levels.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Tzounakas VL, Kriebardis AG, Georgatzakou HT, Foudoulaki-Paparizos LE, Dzieciatkowska M, Wither MJ, et al. Glucose 6-phosphate dehydrogenase deficient subjects may be better “storers” than donors of red blood cells. Free Radic Biol Med 2016;96:152-65.  Back to cited text no. 1
Howes RE, Piel FB, Patil AP, Nyangiri OA, Gething PW, Dewi M, et al. G6PD deficiency prevalence and estimates of affected populations in malaria endemic countries: A geostatistical model-based map. PLoS Med 2012;9:e1001339.  Back to cited text no. 2
Monteiro WM, Val FF, Siqueira AM, Franca GP, Sampaio VS, Melo GC, et al. G6PD deficiency in latin America: Systematic review on prevalence and variants. Mem Inst Oswaldo Cruz 2014;109:553-68.  Back to cited text no. 3
Cappellini MD, Fiorelli G. Glucose-6-phosphate dehydrogenase deficiency. Lancet 2008;371:64-74.  Back to cited text no. 4
Ash-Bernal R, Wise R, Wright SM. Acquired methemoglobinemia: A retrospective series of 138 cases at 2 teaching hospitals. Medicine (Baltimore) 2004;83:265-73.  Back to cited text no. 5
Aneke JC, Okocha CE. Blood transfusion safety; current status and challenges in Nigeria. Asian J Transfus Sci 2017;11:1-5.  Back to cited text no. 6
[PUBMED]  [Full text]  
Alabdulaali MK, Alayed KM, Alshaikh AF, Almashhadani SA. Prevalence of glucose-6-phosphate dehydrogenase deficiency and sickle cell trait among blood donors in Riyadh. Asian J Transfus Sci 2010;4:31-3.  Back to cited text no. 7
[PUBMED]  [Full text]  
Naing L, Winn T, Rusli BN. Practical issues in calculating the sample size for prevalence studies. Arch Orofac Sci 2006;1:9-14.  Back to cited text no. 8
Gilles HM, Fletcher KA, Hendrickse RG, Lindner R, Reddy S, Allan N, et al. Glucose-6-phosphate-dehydrogenase deficiency, sickling, and malaria in African children in South Western Nigeria. Lancet 1967;1:138-40.  Back to cited text no. 9
Lohr GW, Waller HD. Glucose-6-phosphate dehydrogenase. Methods of Enzymatic Analysis. 3rd ed. Wehnheim: Verlag Chemie; 1974. p. 636.  Back to cited text no. 10
Randox Glucose-6-Phosphate Dehydrogenase (G-6-P-D) Manual, E.C. Available from: http://www.syrianagency.com/images/stories/PDF/RandoxApplicationSheets/PD410.pdf. [Last accessed on 2017 Apr 21].  Back to cited text no. 11
Lewis SM, Roper D. Laboratory methods used in the investigation of the haemolytic anaemias. In: Lewis SM, Bain BJ, Bates I, editors. Practical Haematology. 10th ed. PA: Churchill Livingstone; 2006. p. 200-1.  Back to cited text no. 12
Bolarinwa RA, Aneke JC, Olowookere SA, Salawu L. Seroprevalence of transfusion transmissible viral markers in sickle cell disease patients and healthy controls in Ile-Ife, South Western Nigeria: A case-control study. J Appl Hematol 2015;6:162-7.  Back to cited text no. 13
  [Full text]  
Francis RO, Jhang JS, Pham HP, Hod EA, Zimring JC, Spitalnik SL, et al. Glucose-6-phosphate dehydrogenase deficiency in transfusion medicine: The unknown risks. Vox Sang 2013;105:271-82.  Back to cited text no. 14
Egesie OJ, Egesie UG, Jatau ED, Isiguzoro I, Ntuhun DB. Prevalence of sickle cell trait and glucose 6 phosphate dehydrogenase deficiency among blood donors in a Nigerian tertiary hospital. Afr J Biomed Res 2013;16:143-7.  Back to cited text no. 15
Akanni EO, Oseni BS, Agbona WO, Tijani BA, Tosan E, Fakunle EE, et al. Glucose-6-phosphate dehydrogenase deficiency in blood donors and jaundiced neonates in Osogbo, Nigeria. J Med Lab Diagn 2010;1:1-4.  Back to cited text no. 16
Ruwende C, Khoo SC, Snow RW, Yates SN, Kwiatkowski D, Gupta S, et al. Natural selection of hemi- and heterozygotes for G6PD deficiency in Africa by resistance to severe malaria. Nature 1995;376:246-9.  Back to cited text no. 17
Okocha EC, Aneke JC, Ezeh TU, Ibeh NC, Nwosu GA, Okorie IO, et al. The epidemiology of transfusion-transmissible infections among blood donors in Nnewi, South-East Nigeria. Afr J Med Health Sci 2015;14:125-9.  Back to cited text no. 18
  [Full text]  
Aneke CJ, Ezeh UT, Nwosu AG, Anumba EC. Retrospective evaluation of prospective blood donor deferral in a tertiary hospital-based blood bank in South-East Nigeria. J Med Trop 2016;18:103-7.  Back to cited text no. 19
  [Full text]  
John CA, Theodora UE, Gloria AN, Chika EA. Adverse reactions to blood donation: A descriptive study of 3520 blood donors in a Nigerian tertiary hospital. Med J DY Patil Univ 2017;10:36-40.  Back to cited text no. 20
  [Full text]  
Ufelle SA, Neboh EE, Ocheni S, Ikekpeazu JE, Maduka IC. Activity of glucose-6-phosphate dehydrogenase in stored blood. Orient J Med 2014;26:3-4.  Back to cited text no. 21
Foltz LM, Dalal BI, Wadsworth LD, Broady R, Chi K, Eisenhauer E, et al. Recognition and management of methemoglobinemia and hemolysis in a G6PD-deficient patient on experimental anticancer drug triapine. Am J Hematol 2006;81:210-1.  Back to cited text no. 22
Price D. Methaemoglobinaemia. In: Goldfrank's Toxicological Emergencies. 7th ed. New York: McGraw Hill; 2002. p. 143-9.  Back to cited text no. 23
Zama I, Yakubu A, Okwesili AN, Ishaku E, Erhabor O, Mainasara AS, et al. Prevalence of malaria parasitaemia and methaemoglobin levels among blood donors in Sokoto, Nigeria. Internal Medicine Inside 2013;1:4.  Back to cited text no. 24
Okeke CO, Agbasiere FN, Amilo Grace GI, Ifeanyichukwu MO. Methemoglobin levels among malaria parasite-infected blood donors in Nnewi, Southeastern, Nigeria. Trop J Med Res 2017;20:80-3.  Back to cited text no. 25
Clifton J, Leikin J. Methylene blue. Am J Ther 2003;10:289-91.  Back to cited text no. 26


  [Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7]

This article has been cited by
1 Haematological quality and age of donor blood issued for paediatric transfusion to four hospitals in sub-Saharan Africa
Sophie Uyoga,Ayub Mpoya,Peter Olupot-Olupot,Sarah Kiguli,Robert O. Opoka,Charles Engoru,Macpherson Mallewa,Neil Kennedy,Bridon Mębaya,Dorothy Kyeyune,Benjamin Wabwire,Imelda Bates,Diana M. Gibb,Ann Sarah Walker,Elizabeth C. George,Thomas N. Williams,Kathryn Maitland
Vox Sanguinis. 2019;
[Pubmed] | [DOI]


Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
Access Statistics
Email Alert *
Add to My List *
* Registration required (free)

  In this article
Subjects and Methods
Article Tables

 Article Access Statistics
    PDF Downloaded167    
    Comments [Add]    
    Cited by others 1    

Recommend this journal