Barker MK1,2, Henderson AM3,2, Naguib K1,2, Vercauteren SM2,4, Devlin AM3,2, Albert AY5, Bahizire E6,7, Tugirimana PL8, Akilimali PZ9, Boy E10, Green TJ11,12, Karakochuk CD13,2.

1Food, Nutrition, and Health and.2British Columbia Children’s Hospital Research Institute, Vancouver, British Columbia, Canada.3Department of Pediatrics, University of British Columbia, Vancouver, British Columbia, Canada.4Hematopathology, British Columbia Children’s Hospital, Vancouver, British Columbia, Canada.5Women’s Health Research Institute, British Columbia Women’s Hospital and Health Centre, Vancouver, British Columbia, Canada.6Faculty of Medicine, Catholic University of Bukavu, Bukavu, Democratic Republic of Congo.7Center of Research in Epidemiology, Biostatistics and Clinical Research, Free University of Brussels, Brussels, Belgium.8Faculty of Medicine, University of Goma, Goma, Democratic Republic of the Congo.9Department of Nutrition, Kinshasa School of Public Health, University of Kinshasa, Kinshasa, Democratic Republic of the Congo.10HarvestPlus, International Food Policy Research Institute, Washington, DC.11Healthy Mothers, Babies, and Children, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia; and.12Discipline of Paediatrics, University of Adelaide, Adelaide, South Australia, Australia.13Food, Nutrition, and Health and crystal.karakochuk@ubc.ca.


Abstract

Background: Anemia is common in Congolese children, and inherited blood disorders may be a contributing cause. The presence of sickle cell variants, X-linked glucose-6-phosphate dehydrogenase (G6PD) deficiency and α-thalassemia, has been previously reported. G6PD A- deficiency is characterized by the co-inheritance of G6PD 376 and 202 variants and is common in sub-Saharan Africa.

Objective: We aimed to measure the associations between inherited blood disorders and hemoglobin, ferritin, and soluble transferrin receptor (sTfR) concentrations in Congolese children.

Methods: Venous blood was collected from 744 children aged 6-59 mo from 2 provinces. We measured biomarkers of nutritional and inflammation status and malaria. Pyrosequencing was used to detect sickle cell variants. Polymerase chain reaction was used to detect G6PD variants and α-thalassemia deletions.

Results: Overall, 11% of children had a sickle cell variant, 19% of boys were G6PD A- hemizygotes, 12% and 10% of girls were G6PD A- hetero- or homozygotes, respectively, and 12% of children had α-thalassemia. Multivariable linear regression models (adjusted for age, province, altitude, malaria, and biomarkers of nutritional and inflammation status) showed that G6PD A- hemizygous boys and G6PD 376 homozygous girls had higher sTfR concentrations [geometric mean ratios (95% CIs): 1.20 (1.03, 1.39) and 1.25 (1.02, 1.53), respectively] than children with no G6PD variants. Hemoglobin and ferritin concentrations were not independently associated with any of the inherited blood disorder genotypes.

Conclusions: We found that 2 G6PDvariant genotypes were associated with elevated sTfR concentrations, which limits the accuracy of sTfR as a biomarker of iron status in this population.

KEYWORDS:

Congo; anemia; biomarkers; ferritin; glucose-6-phosphate dehydrogenase; hemoglobinopathy; inflammation; iron; malaria; variant