Background
The objectives of this study are to estimate the prevalence of iron deficiency (ID) among French whole‐blood (WB) donors to identify factors associated with ID and to generate decision trees.
Study design and methods
A prospective National multicentre study was performed on WB donors from March 11, to April 5th, 2019. Samples were selected randomly to perform serum ferritin. ID was defined as ferritin value under 26 ng/ml. All results were stratified by sex. Factors associated with ID were analysed using multivariate logistic regression model. CART algorithm was used for decision trees.
Results
Eleven thousand two hundred fifty eight WB donors were included. ID was more frequent in women (39·5%) than in men (18·0%). Among 7200 repeated donors, women below 50 yo had a higher risk (OR = 2·37; [1·97–2·85] IC95) than those above 50 yo. Factors associated with ID were: haemoglobin level under the threshold at donation n‐1 except for women and n‐2 donation; a low mean corpuscular haemoglobin at n‐1 and n‐2 donations; a shorter interval since n‐1 donation and between n‐1 and n‐2 donations except for women; and women who had given three or four times in the last year. CART algorithm defined high risk of ID subgroups within three populations of donors, new female donors, repeated male donors and repeated female donors. In these identified subgroups, prevalence of ID was up to 72·1%.
Conclusions
Our study showed the high prevalence of ID among French WB donors, identified well‐known and new factors associated with ID and defined algorithms predicting ID in three populations.
IntroductionCurrent approved COVID-19 vaccines, notably mRNA and adenoviral vectored technologies, still fail to fully protect against infection and transmission of various SARS-CoV-2 variants. The mucosal immunity at the upper respiratory tract represents the first line of defense against respiratory viruses such as SARS-CoV-2 and is thus critical to develop vaccine blocking human-to-human transmission.MethodsWe measured systemic and mucosal Immunoglobulin A (IgA) response in serum and saliva from 133 healthcare workers from Percy teaching military hospital following a mild infection (SARS-CoV-2 Wuhan strain, n=58) or not infected (n=75), and after SARS-CoV-2 vaccination (Vaxzevria®/Astrazeneca and/or Comirnaty®/Pfizer).ResultsWhile serum anti-SARS-CoV-2 Spike IgA response lasted up to 16 months post-infection, IgA response in saliva had mostly fallen to baseline level at 6 months post-infection. Vaccination could reactivate the mucosal response generated by prior infection, but failed to induce a significant mucosal IgA response by itself. Early post-COVID-19 serum anti-Spike-NTD IgA titer correlated with seroneutralization titers. Interestingly, its saliva counterpart positively correlated with persistent smell and taste disorders more than one year after mild COVID-19.DiscussionAs breakthrough infections have been correlated with IgA levels, other vaccine platforms inducing a better mucosal immunity are needed to control COVID-19 infection in the future. Our results encourage further studies to explore the prognosis potential of anti-Spike-NTD IgA in saliva at predicting persistent smell and taste disorders.
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