RESUMO
Introduction: Regular whole blood donors often suffer from iron deficiency (ID) or iron deficiency anemia due to the loss of 200-300 mg of iron with each donation. Hemoglobin (Hb) as donor eligibility criterion reflects iron stores only poorly. ID in blood donors is typically prevented or treated with orally administered ferrous salts, which frequently cause gastrointestinal side effects. A high daily oral iron dose is counterproductive due to hepcidin upregulation. Oral sucrosomial iron (sucriron) is encapsulated ferric pyrophosphate that may be an option for blood donors due to its supposed high bioavailability and good tolerability. Methods: This monocentric single-cohort pilot study included fifty whole blood donors (divided into premenopausal women, postmenopausal women, and men) who did not meet Hb donation criteria. Participants aged 18-65 years with ferritin <30 ng/mL and venous Hb <12.5 g/dL in women and Hb <13.5 g/dL in men received oral sucriron (30 mg iron) for 90-120 days. Primary endpoints were the increase of Hb and ferritin. Results: Forty-seven participants completed the study. With the limitation that no control group was included, there was a substantial overall median increase of 0.94 g/dL Hb and 4.97 ng/mL ferritin (standardized on 90 days of iron intake). These value improvements were likewise observed in each of the subgroups. sucriron was very well tolerated, with almost no gastrointestinal side effects identified. Conclusion: A clear increase of Hb and ferritin was observed after the intake of sucriron, so it may be a reasonable and useful alternative to traditional oral iron therapy. The ease of administration, pleasant taste, dietary supplement status, and, most importantly, good tolerability highlight the value of sucriron supplementation.
RESUMO
CONTEXT.: Serologic tests on automated immunology analyzers are increasingly used to monitor acquired immunity against SARS-CoV-2. The heterogeneity of assays raises concerns about their diagnostic performance and comparability. OBJECTIVE.: To test sera from formerly infected individuals for SARS-CoV-2 antibodies by using 6 automated serology assays and a pseudoneutralization test (PNT). DESIGN.: Six SARS-CoV-2 serology assays were used to assess 954 samples collected during a 12-month period from 315 COVID-19 convalescents. The tests determined either antibodies against the viral nucleocapsid (anti-NC) or spike protein (anti-S). Two assays did not distinguish between antibody classes, whereas the others selectively measured immunoglobulin G (IgG) antibodies. PNT was used to detect the presence of neutralizing antibodies. RESULTS.: Comparison of qualitative results showed only slight to moderate concordance between the assays (Cohen κ < 0.57). Significant correlations (P < .001) were observed between the antibody titers from all quantitative assays. However, titer changes were not detected equally. A total anti-S assay measured an increase in 128 of 172 cases (74%) of a suitable subset, whereas all IgG anti-S tests reported decreases in at least 118 (69%). Regarding the PNT results, diagnostic sensitivities of 89% or greater were achieved with positive predictive values of at least 93%. In contrast, specificity changed substantially over time, varying from 20% to 100%. CONCLUSIONS.: Comparability of serologic SARS-CoV-2 antibody tests is rather poor. Owing to different diagnostic specificities, the tested assays were not equally capable of capturing changes in antibody titers. However, with thoroughly validated cutoffs, IgG-selective anti-S assays are a reliable surrogate test for SARS-CoV-2 neutralizing antibodies in former COVID-19 patients.
