{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,12,31]],"date-time":"2025-12-31T10:13:43Z","timestamp":1767176023312,"version":"build-2238731810"},"update-to":[{"DOI":"10.12688\/wellcomeopenres.15750.1","type":"new_version","label":"New version","source":"publisher","updated":{"date-parts":[[2020,6,2]],"date-time":"2020-06-02T00:00:00Z","timestamp":1591056000000}}],"reference-count":43,"publisher":"F1000 Research Ltd","license":[{"start":{"date-parts":[[2020,6,2]],"date-time":"2020-06-02T00:00:00Z","timestamp":1591056000000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000265","name":"Medical Research Council","doi-asserted-by":"publisher","award":["MC-A760-5QX00"],"award-info":[{"award-number":["MC-A760-5QX00"]}],"id":[{"id":"10.13039\/501100000265","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000071","name":"National Institute of Child Health and Human Development","doi-asserted-by":"publisher","award":["MC-A760-5QX00"],"award-info":[{"award-number":["MC-A760-5QX00"]}],"id":[{"id":"10.13039\/100000071","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000865","name":"Bill and Melinda Gates Foundation","doi-asserted-by":"publisher","award":["MC-A760-5QX00"],"award-info":[{"award-number":["MC-A760-5QX00"]}],"id":[{"id":"10.13039\/100000865","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100014163","name":"Alliance for Accelerating Excellence in Science in Africa","doi-asserted-by":"crossref","award":["DEL-15-003"],"award-info":[{"award-number":["DEL-15-003"]}],"id":[{"id":"10.13039\/501100014163","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/100010269","name":"Wellcome Trust","doi-asserted-by":"crossref","award":["110255, 212600, 203077, 203141, 206194, 107769"],"award-info":[{"award-number":["110255, 212600, 203077, 203141, 206194, 107769"]}],"id":[{"id":"10.13039\/100010269","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":["wellcomeopenresearch.org"],"crossmark-restriction":false},"short-container-title":["Wellcome Open Res"],"abstract":"\n Background<\/ns7:bold>\n : Anaemia is a major public health concern especially in African children living in malaria-endemic regions. Interferon-gamma (IFN-\u03b3) is elevated during malaria infection and is thought to influence erythropoiesis and iron status. Genetic variants in the IFN-\u03b3 gene\n (IFNG<\/ns7:italic>\n ) are associated with increased IFN-\u03b3 production. We investigated putative functional single nucleotide polymorphisms (SNPs) and haplotypes of\n IFNG<\/ns7:italic>\n in relation to nutritional iron status and anaemia in Gambian children over a malaria season.\n <\/ns7:p>\n \n Methods:<\/ns7:bold>\n We used previously available data from Gambian family trios to determine informative SNPs and then used the Agena Bioscience MassArray platform to type five SNPs from the\n IFNG<\/ns7:italic>\n gene in a cohort of 780 Gambian children aged 2-6 years. We also measured haemoglobin and biomarkers of iron status and inflammation at the start and end of a malaria season.\n <\/ns7:p>\n \n Results:<\/ns7:bold>\n We identified five\n IFNG<\/ns7:italic>\n haplotype-tagging SNPs (\n IFNG<\/ns7:italic>\n -1616 [rs2069705],\n IFNG<\/ns7:italic>\n +874 [rs2430561],\n IFNG<\/ns7:italic>\n +2200 [rs1861493],\n IFNG<\/ns7:italic>\n +3234 [rs2069718] and\n IFNG<\/ns7:italic>\n +5612 [rs2069728]). The\n IFNG<\/ns7:italic>\n +2200C [rs1861493] allele was associated with reduced haemoglobin concentrations (adjusted \u03b2 -0.44 [95% CI -0.75, -0.12]; Bonferroni adjusted P = 0.03) and a trend towards iron deficiency compared to wild-type at the end of the malaria season in multivariable models adjusted for potential confounders. A haplotype uniquely identified by\n IFNG<\/ns7:italic>\n +2200C was similarly associated with reduced haemoglobin levels and trends towards iron deficiency, anaemia and iron deficiency anaemia at the end of the malaria season in models adjusted for age, sex, village, inflammation and malaria parasitaemia.\n <\/ns7:p>\n \n Conclusion:<\/ns7:bold>\n We found limited statistical evidence linking\n IFNG<\/ns7:italic>\n polymorphisms with a risk of developing iron deficiency and anaemia in Gambian children. More definitive studies are needed to investigate the effects of genetically influenced IFN-\u03b3 levels on the risk of iron deficiency and anaemia in children living in malaria-endemic areas.\n <\/ns7:p>","DOI":"10.12688\/wellcomeopenres.15750.2","type":"journal-article","created":{"date-parts":[[2020,6,2]],"date-time":"2020-06-02T09:55:07Z","timestamp":1591091707000},"page":"40","update-policy":"https:\/\/doi.org\/10.12688\/wellcomeopenres.crossmark-policy","source":"Crossref","is-referenced-by-count":2,"title":["Interferon-gamma polymorphisms and risk of iron deficiency and anaemia in Gambian children"],"prefix":"10.12688","volume":"5","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5726-1776","authenticated-orcid":false,"given":"Kelvin M.","family":"Abuga","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6369-9299","authenticated-orcid":false,"given":"Kirk A.","family":"Rockett","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4369-9547","authenticated-orcid":false,"given":"John Muthii","family":"Muriuki","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3454-2855","authenticated-orcid":false,"given":"Oliver","family":"Koch","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Manfred","family":"Nairz","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0244-6343","authenticated-orcid":false,"given":"Giorgio","family":"Sirugo","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2135-7549","authenticated-orcid":false,"given":"Philip","family":"Bejon","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5023-0176","authenticated-orcid":false,"given":"Dominic P.","family":"Kwiatkowski","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Andrew M.","family":"Prentice","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8360-4402","authenticated-orcid":false,"given":"Sarah H.","family":"Atkinson","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"2560","published-online":{"date-parts":[[2020,6,2]]},"reference":[{"key":"ref-1","article-title":"World malaria report 2019.","year":"2019"},{"key":"ref-2","doi-asserted-by":"publisher","first-page":"515-8","DOI":"10.1038\/nature24059","article-title":"The prevalence of Plasmodium falciparum in sub-Saharan Africa since 1900.","volume":"550","author":"R Snow","year":"2017","journal-title":"Nature."},{"key":"ref-3","article-title":"The global prevalence of anaemia in 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Research"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/wellcomeopenresearch.org\/articles\/5-40\/v2\/xml","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/wellcomeopenresearch.org\/articles\/5-40\/v2\/pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/wellcomeopenresearch.org\/articles\/5-40\/v2\/iparadigms","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,2,18]],"date-time":"2023-02-18T12:16:57Z","timestamp":1676722617000},"score":1,"resource":{"primary":{"URL":"https:\/\/wellcomeopenresearch.org\/articles\/5-40\/v2"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,6,2]]},"references-count":43,"URL":"https:\/\/doi.org\/10.12688\/wellcomeopenres.15750.2","relation":{},"ISSN":["2398-502X"],"issn-type":[{"value":"2398-502X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,6,2]]},"assertion":[{"value":"Indexed","URL":"https:\/\/wellcomeopenresearch.org\/articles\/5-40\/v2#article-reports","order":0,"name":"referee-status","label":"Referee status","group":{"name":"current-referee-status","label":"Current Referee Status"}},{"value":"10.21956\/wellcomeopenres.17270.r38239, John Michael Ong\u2019echa, Center for Global Health Research, Kenya Medical Research Institute\u00a0(KEMRI), Kisumu, Kenya, 23 Apr 2020, version 1, indexed","URL":"https:\/\/wellcomeopenresearch.org\/articles\/5-40\/v1#referee-response-38239","order":0,"name":"referee-response-38239","label":"Referee Report","group":{"name":"article-reports","label":"Article Reports"}},{"value":"Sarah Atkinson<\/b>; \nPosted: 27 May 2020<\/i>; We thank the reviewer for his helpful comments, which we have addressed point-by-point below:   \nReviewer #1<\/b> \nAbstract: It would be good if the authors provided the age range of children enrolled in the study (2 \u2013 6 years).This could be added in the Methods section at the end of the sentence \u2018\u2026.780 Gambian children.\u2019<\/b> \nResponse: Thank you for the suggestion. We have added the age range (2-6 years) in the methods section of the abstract.<\/i>   \nAbstract, Methods: \u201cWe used previously available data from Gambian family trios to determine informative SNPs and then used the Agena Bioscience MassArray platform to type five SNPs from the IFNG gene in a cohort of 780 Gambian children aged 2-6 years\u201d.<\/i>   \n2. The last sentence at the end of the Results section mentions a number of covariates that were adjusted for in the models. One such covariate is \u2018malaria parasitaemia\u2019. <\/b> \na) Was malaria parasitaemia adjusted for only at the beginning and at the end of the malaria season or did it capture all the malaria cases during the study period?<\/b>   \nResponse: In the current analysis, we adjusted for malaria parasitaemia detected on blood film at the beginning and at the end of the malaria season, at the same timepoints when iron biomarkers were measured since malaria parasitaemia influences markers of iron status. We did not monitor for malaria cases during the malaria season. <\/i> \nMethods, under Statistical analyses: \u201cMultivariable regression models were adjusted for age (grouped by year), sex, village (which also acted as a proxy for ethnic group), malaria parasitaemia and ACT at the start and end of the malaria season.\u201d<\/i> \nb)  Does \u2018malaria parasitaemia\u2019 mean malaria episodes during the study period?<\/b> \nResponse: Malaria parasitaemia referred to the identification of Plasmodium parasites on the blood film taken from the study participants at either of the two cross-sectional timepoints, i.e. at the beginning and \/ or end of the malaria season. It does not refer to malaria episodes during the study period.<\/i>   \nc) If it only captures the two time points, what would the effect of \u2018additional episodes\u2019 during the study period have on the results? In malaria endemic areas, repeated infections are more likely to result in anaemia than just the patent infection. The authors need to clarify on this and if there were no malaria cases in-between the two time-points they need to indicate so.<\/b> \nResponse: We agree that repeated malaria episodes would increase the risk of anaemia. Based on published data we estimated that the majority of the children would be likely to have had one or more episodes of malaria over the malaria season during the study period.<\/i>\n1<\/sup><\/i>\n Studies indicate that malaria increases IFN-<\/i>\ng<\/i>\n levels<\/i>\n2<\/sup>\n and that IFN-<\/i>\ng<\/i>\n regulates erythropoiesis and iron-regulatory proteins including hepcidin.<\/i>\n3-6<\/sup> \nWe therefore hypothesized that IFNG SNPs, which might alter IFNG expression, would influence iron status at the end of the malaria season. Thus, we would expect that the effect of \u2018additional episodes\u2019 of malaria would be to increase malaria-induced IFN-<\/i>\ng<\/i>\n  levels and IFN-<\/i>\ng<\/i>\n -induced iron deficiency and anaemia. To clarify we have updated the Methods section as follows: <\/i> \nMethods, under Laboratory methods: \u201cGiemsa-stained thick and thin blood films were examined for Plasmodium falciparum and other Plasmodium species at the start and end of the malaria season.\u201d <\/i>  ","URL":"https:\/\/wellcomeopenresearch.org\/articles\/5-40\/v2#referee-comment-4188","order":1,"name":"referee-comment-4188","label":"Referee Comment","group":{"name":"article-reports","label":"Article Reports"}},{"value":"Sarah Atkinson<\/b>; \nPosted: 27 May 2020<\/i>; We thank the reviewer for his helpful comments, which we have addressed point-by-point below:   \nAbstract: It would be good if the authors provided the age range of children enrolled in the study (2 \u2013 6 years).This could be added in the Methods section at the end of the sentence \u2018\u2026.780 Gambian children.\u2019<\/b>   \nResponse: Thank you for the suggestion. We have added the age range (2-6 years) in the methods section of the abstract.<\/i>   \nAbstract, Methods: \u201cWe used previously available data from Gambian family trios to determine informative SNPs and then used the Agena Bioscience MassArray platform to type five SNPs from the IFNG gene in a cohort of 780 Gambian children aged 2-6 years\u201d.<\/i>   \n2. The last sentence at the end of the Results section mentions a number of covariates that were adjusted for in the models. One such covariate is \u2018malaria parasitaemia\u2019. <\/b> \na) Was malaria parasitaemia adjusted for only at the beginning and at the end of the malaria season or did it capture all the malaria cases during the study period?<\/b>   \nResponse: In the current analysis, we adjusted for malaria parasitaemia detected on blood film at the beginning and at the end of the malaria season, at the same timepoints when iron biomarkers were measured since malaria parasitaemia influences markers of iron status. We did not monitor for malaria cases during the malaria season. <\/i> \nMethods, under Statistical analyses: \u201cMultivariable regression models were adjusted for age (grouped by year), sex, village (which also acted as a proxy for ethnic group), malaria parasitaemia and ACT at the start and end of the malaria season.\u201d<\/i>   \nb) Does \u2018malaria parasitaemia\u2019 mean malaria episodes during the study period?<\/b> \nResponse: Malaria parasitaemia referred to the identification of Plasmodium parasites on the blood film taken from the study participants at either of the two cross-sectional timepoints, i.e. at the beginning and \/ or end of the malaria season. It does not refer to malaria episodes during the study period.<\/i>   \nc) If it only captures the two time points, what would the effect of \u2018additional episodes\u2019 during the study period have on the results? In malaria endemic areas, repeated infections are more likely to result in anaemia than just the patent infection. The authors need to clarify on this and if there were no malaria cases in-between the two time-points they need to indicate so.<\/b> \nResponse: We agree that repeated malaria episodes would increase the risk of anaemia. Based on published data we estimated that the majority of the children would be likely to have had one or more episodes of malaria over the malaria season during the study period.<\/i>\n1<\/sup><\/i>\n Studies indicate that malaria increases IFN-<\/i>\ng<\/i>\n levels<\/i>\n2<\/sup>\n and that IFN-<\/i>\ng<\/i>\n regulates erythropoiesis and iron-regulatory proteins including hepcidin.<\/i>\n3-6<\/sup> \nWe therefore hypothesized that IFNG SNPs, which might alter IFNG expression, would influence iron status at the end of the malaria season. Thus, we would expect that the effect of \u2018additional episodes\u2019 of malaria would be to increase malaria-induced IFN-<\/i>\ng<\/i>\n  levels and IFN-<\/i>\ng<\/i>\n -induced iron deficiency and anaemia. To clarify we have updated the Methods section as follows: <\/i> \nMethods, under Laboratory methods: \u201cGiemsa-stained thick and thin blood films were examined for Plasmodium falciparum and other Plasmodium species at the start and end of the malaria season.\u201d <\/i>   \nReferences<\/b> 1.         Ceesay SJ, Casals-Pascual C, Erskine J, et al. Changes in malaria indices between 1999 and 2007 in The Gambia: a retrospective analysis. \nLancet (London, England)<\/i> 2008; \n372<\/b>(9649): 1545-54. 2.         McCall MB, Sauerwein RW. Interferon-gamma--central mediator of protective immune responses against the pre-erythrocytic and blood stage of malaria. \nJournal of leukocyte biology<\/i> 2010; \n88<\/b>(6): 1131-43. 3.         Frazier MD, Mamo LB, Ghio AJ, Turi JL. Hepcidin expression in human airway epithelial cells is regulated by interferon-\u03b3. \nRespiratory research<\/i> 2011; \n12<\/b>(1): 100. 4.         Nairz M, Fritsche G, Brunner P, Talasz H, Hantke K, Weiss G. Interferon-gamma limits the availability of iron for intramacrophage Salmonella typhimurium. \nEuropean journal of immunology<\/i> 2008; \n38<\/b>(7): 1923-36. 5.         Ludwiczek S, Aigner E, Theurl I, Weiss G. Cytokine-mediated regulation of iron transport in human monocytic cells. \nBlood<\/i> 2003; \n101<\/b>(10): 4148-54. 6.         Byrd TF, Horwitz MA. Regulation of transferrin receptor expression and ferritin content in human mononuclear phagocytes. Coordinate upregulation by iron transferrin and downregulation by interferon gamma. \nThe Journal of clinical investigation<\/i> 1993; \n91<\/b>(3): 969-76.","URL":"https:\/\/wellcomeopenresearch.org\/articles\/5-40\/v2#referee-comment-4190","order":2,"name":"referee-comment-4190","label":"Referee Comment","group":{"name":"article-reports","label":"Article Reports"}},{"value":"10.21956\/wellcomeopenres.17270.r38445, Laura Silvestri, Regulation of Iron Metabolism Unit, Division of Genetics and Cell Biology, San Raffaele Scientific Institute, Milan, Italy, 05 May 2020, version 1, indexed","URL":"https:\/\/wellcomeopenresearch.org\/articles\/5-40\/v1#referee-response-38445","order":3,"name":"referee-response-38445","label":"Referee Report","group":{"name":"article-reports","label":"Article Reports"}},{"value":"Sarah Atkinson<\/b>; \nPosted: 27 May 2020<\/i>; Thank you for your helpful comments.  \na) Serum hepcidin levels are influenced by circadian rhythm and serum\/iron stores. Please indicate at what time of the day blood was drawn.<\/b> \nResponse: Thank you, Blood was drawn from the participants in the morning hours (between 6 and 11AM). We have updated the study design section to indicate the time of sample collection.<\/i> \nMethods, under Study design:<\/i> \u201c\nAll children had a clinical examination and a blood sample collected in the morning between 6 and 11 am for full blood count, malaria film, and biomarkers of iron status and inflammation at the start and end of the malaria season.\u201d<\/i> \nb) To \u201cnormalize\u201d serum hepcidin to body iron concentration, the hepcidin\/ferritin or hepcidin\/TSAT ratio should be shown in Table 1 and Table 3 (as in Donker et al., Pediatric Blood and Cancer 2019).<\/b> \nResponse: Thank you for the suggestion. We have added hepcidin\/ferritin and transferrin saturation (TSAT)\/hepcidin ratios to tables 1 and 3. We have also made the following changes:<\/i> \nMethods section under laboratory methods: Hepcidin\/ferritin and TSAT\/hepcidin ratios were also calculated<\/i>.\n1<\/sup> \nResults section under Characteristics of participants: We found that hepcidin and hepcidin\/ferritin ratio decreased while the TSAT\/hepcidin ratio increased across the malaria season in keeping with the need for increased erythropoiesis and increased rates of iron absorption at the end of the malaria season.<\/i>   \n2. In the M&M section, the authors claim that some children are carriers of the HbAS, and G6PD deficiency. Is it possible to present the haematological and iron data (in Table 1 and Table 3) related to these children?<\/b> \nResponse: Thank you for this suggestion. We have now added haemoglobin and iron biomarker data for children with HbAS and G6PD deficiency as a Supplementary file (Extended datafile 3) that can be accessed on Figshare (<\/i>\nhttps:\/\/doi.org\/10.6084\/m9.figshare.11807277<\/i>\n.v6<\/i>\n). We have also made the following changes to the Results section:<\/i> \nResults under Characteristics of participants: \u201cA total of 99\/751 (13.2%) children carried sickle cell trait (HbAS) and 136\/683 (19.9%) children G6PD deficiency and the effects of these polymorphisms on iron status and anaemia are shown in Extended datafile 3.<\/i>\n2<\/i><\/sup>\n At the start of the malaria season we found little difference in iron status in children with HbAS and G6PD deficiency compared to those with wild-type. At the end of the malaria season, children carrying HbAS had lower zinc protoporphyrin levels (97.0 [95% CI 87.0, 108.2]) compared to those with HbAA (115.9 [95% CI 110.6, 121.3]; adj. P = 0.05) and children with G6PD deficiency had lower haemoglobin levels (9.7 g\/dl [95% CI 9.4, 10.0]) than those with G6PD wild-type genotype (10.0 g\/dl [95% CI 9.9, 10.2]; adj. P = 0.01).\u201d<\/i>     \nReferences<\/b> 1.         Donker AE, Galesloot TE, Laarakkers CM, Klaver SM, Bakkeren DL, Swinkels DW. Standardized serum hepcidin values in Dutch children: Set point relative to body iron changes during childhood. \nPediatr Blood Cancer<\/i> 2020; \n67<\/b>(3): e28038. 2.         Abuga KM, Robert KA, Muriuki JM, et al. IFNG polymorphisms in Gambian children and risk of iron deficiency and anaemia. 2020. https:\/\/doi.org\/10.6084\/m9.figshare.11807277.","URL":"https:\/\/wellcomeopenresearch.org\/articles\/5-40\/v2#referee-comment-4189","order":4,"name":"referee-comment-4189","label":"Referee Comment","group":{"name":"article-reports","label":"Article Reports"}},{"value":"This work was supported by Wellcome [110255 to SHA; 212600 to KMA] and core awards to the KEMRI-Wellcome Trust Research Programme [203077], the Wellcome Centre for Human Genetics [203141] and the Wellcome Sanger Institute [206194]. KMA and JMM were supported by the DELTAS Africa Initiative [DEL-15-003]. The DELTAS Africa Initiative is an independent funding scheme of the African Academy of Sciences (AAS)'s Alliance for Accelerating Excellence in Science in Africa (AESA) and supported by the New Partnership for Africa's Development Planning and Coordinating Agency (NEPAD Agency) with funding from Wellcome [107769] and the UK government. The Gambian studies were supported by the National Institute of Child Health and Development, Bill and Melinda Gates Foundation, core funding MC-A760-5QX00 to the MRC Unit, The Gambia\/MRC International Nutrition Group by the UK MRC and the UK Department for International Development (DFID) under the MRC\/DFID Concordat agreement. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.","order":5,"name":"grant-information","label":"Grant Information"},{"value":"This is an open access article distributed under the terms of the Creative Commons Attribution Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.","order":0,"name":"copyright-info","label":"Copyright"}]}}