A Tutsi family harbouring two new RHCE variant alleles and a new haplotype in the Rh blood group system.

BACKGROUND: RHCE*ceEK is a rare RH allele mostly encountered in people of African descent. This allele is defined by four single nucleotide substitutions: c.48G>C, c.712A>G, c.787A>G and c.800T>A. Until now, it has only been reported to segregate with either RHD*01N.01 or RHD*DAR1.00. MATERIALS AND METHODS: Blood samples were drawn from a 32-year-old Tutsi pregnant woman during an antenatal visit in order to perform her type and screen. To further investigate the results found in the patient, a family study was conducted. Standard haemagglutination methods were used to investigate the subjects' red blood cells and plasma. Molecular workup on RHD and RHCE genes was carried out by DNA microarray, real-time PCR and DNA sequencing techniques. RESULTS: The patient was phenotyped as group B, D+C-E-c+e+, Hr-. A complex mixture of anti-E, anti-c, anti-Hr and anti-hrS was detected in her plasma. She was found to carry a normal RHD gene, a conventional RHCE*ceEK allele and an alternative RHCE*ceEK allele (RHCE*ceEK without c.48G>C). The family study showed that the conventional RHCE*ceEK and the alternative RHCE*ceEK alleles were associated with a RHD*01 allele and a RHD*01N.01 allele, respectively. Molecular analysis performed in the proband's mother showed a novel RHCE*ce variant allele on a RHCE*ceS -like background (RHCE*ceS with c.609G>A). CONCLUSIONS: This case study brought out new associations between RHD and RHCE alleles encoding the rare Hr- phenotype: the conventional RHCE*ceEK allele linked to the RHD*01 allele and an alternative RHCE*ceEK allele associated with the RHD*01N.01 allele. A novel RHCE*ce variant (RHCE*ceS with c.609G>A) was also reported.

Acute hemolytic transfusion reaction associated with anti-Mta : case report and review of the literature.

BACKGROUND: Mta (MNS14) is a low-prevalence antigen of the MNS system. A few cases of hemolytic disease of the fetus and newborn caused by anti-Mta have been reported in the literature, but up to now this antibody has never been associated with a hemolytic transfusion reaction (HTR). CASE REPORT: A 38-year-old male with sickle cell disease undergoing exchange transfusion presented with shivering, nausea, dyspnea, and pain in the lower limbs. Biologic parameters showed increased hemolysis. The administered red blood cell (RBC) units had been issued by electronic crossmatch due to a negative antibody screening test. In the posttransfusion investigations, crossmatch of the transfused RBC units with the patient's serum showed incompatibility of one unit. The presence of an antibody against a low-prevalence antigen was suspected and further serologic testing was performed for identification. RESULTS: Anti-Mta was identified in the patient's serum. The RBCs of the incompatible unit implicated in the HTR were Mt(a+). An eluate of a posttransfusion blood sample of the patient was nonreactive with the incompatible RBCs, and the direct antiglobulin test was negative. CONCLUSION: To our knowledge, this is the first case report of an HTR associated with anti-Mta .

Management of sickle cell disease during pregnancy: experience in a third-level hospital and future recommendations.

OBJECTIVE: To describe the outcomes of sickle-cell disease in pregnancy according to the different treatments adopted before and during pregnancy and to propose a systematic approach to treat sickle-cell disease (SCD) during pregnancy. METHODS: A retrospective descriptive study compared pregnancy outcomes among women with SCD who stopped hydroxyurea (HU) once pregnant (Group 1), were never treated before and during pregnancy (Group 2) or were treated by HU before conception who received prophylactic transfusion during pregnancy (Group 3). For each group we recorded the population's characteristics and the transfusion-related, obstetrical, perinatal and SCD complications. RESULTS: We found 11 patients for group 1 (9/11 with at least 3 painful crises during the 12 months before conception), 4 for group 2 (3/4 with no sickle-cell complications during the year before pregnancy) and 2 for group 3 (one with previous multiorgan failure (MOF), one with previous stroke). No transfusion-related complication occurred. Group 1 and 2 developed SCD complications and a high number of acute transfusions and hospital admissions. Group 3 showed none of these complications, but one patient developed preeclampsia and preterm birth. Several obstetrical and perinatal complications occurred in group 1. CONCLUSION: Not treating sickle-cell during pregnancy increases maternal and perinatal morbidity, even in mildly affected women. All sickle-cell pregnancies should be treated, according to the treatment adopted before but also to patient's SCD-history. We propose chronic transfusion to women with previous stroke or MOF or already under transfusion program, and HU for severely and mildly affected patients, respectively from the second and third trimesters. Additional prospective studies are needed to validate the results of the proposed protocol.

Low Levels of Natural Anti-α-N-Acetylgalactosamine (Tn) Antibodies Are Associated With COVID-19.

Human serum contains large amounts of anti-carbohydrate antibodies, some of which may recognize epitopes on viral glycans. Here, we tested the hypothesis that such antibodies may confer protection against COVID-19 so that patients would be preferentially found among people with low amounts of specific anti-carbohydrate antibodies since individual repertoires vary considerably. After selecting glycan epitopes commonly represented in the human anti-carbohydrate antibody repertoire that may also be expressed on viral glycans, plasma levels of the corresponding antibodies were determined by ELISA in 88 SARS-CoV-2 infected individuals, including 13 asymptomatic, and in 82 non-infected controls. We observed that anti-Tn antibodies levels were significantly lower in patients as compared to non-infected individuals. This was not observed for any of the other tested carbohydrate epitopes, including anti-αGal antibodies used as a negative control since the epitope cannot be synthesized by humans. Owing to structural homologies with blood groups A and B antigens, we also observed that anti-Tn and anti-αGal antibodies levels were lower in blood group A and B, respectively. Analyses of correlations between anti-Tn and the other anti-carbohydrates tested revealed divergent patterns of correlations between patients and controls, suggesting qualitative differences in addition to the quantitative difference. Furthermore, anti-Tn levels correlated with anti-S protein levels in the patients' group, suggesting that anti-Tn might contribute to the development of the specific antiviral response. Overall, this first analysis allows to hypothesize that natural anti-Tn antibodies might be protective against COVID-19.

Covid-19 and blood groups: ABO antibody levels may also matter.

BACKGROUND: Susceptibility to Covid-19 has been found to be associated with the ABO blood group, with O type individuals being at a lower risk. However, the underlying mechanism has not been elucidated. Here, we aimed to test the hypothesis that Covid-19 patients might have lower levels of ABO antibodies than non-infected individuals as they could offer some degree of protection. METHODS: After showing that the viral spike protein harbors the ABO glycan epitopes when produced by cells expressing the relevant glycosyltransferases, like upper respiratory tract epithelial cells, we enrolled 290 patients with Covid-19 and 276 asymptomatic controls to compare their levels of natural ABO blood group antibodies. RESULTS: We found significantly lower IgM anti-A + anti-B agglutination scores in blood group O patients (76.93 vs 88.29, P-value = 0.034) and lower levels of anti-B (24.93 vs 30.40, P-value = 0.028) and anti-A antibodies (28.56 vs 36.50, P-value = 0.048) in blood group A and blood group B patients, respectively, compared to controls. CONCLUSION: In this study, we showed that ABO antibody levels are significantly lower in Covid-19 patients compared to controls. These findings could indicate that patients with low levels of ABO antibodies are at higher risk of being infected.

Hepcidin-25: Measurement by LC-MS/MS in serum and urine, reference ranges and urinary fractional excretion.

A liquid chromatography tandem-mass spectrometry (LC-MS/MS) method was developed for reliably quantifying hepcidin-25 in human urine and serum. A 95% reference range was established for serum hepcidin-25 levels by standardizing the sampling time between 8:00am and 11:00am in 90 apparently healthy volunteers. The association between hepcidin-25 concentration and other biological parameters was studied using multivariable analysis and the coefficient of renal excretion of hepcidin-25 was calculated. Preanalytical variables were also investigated. The LC-MS/MS method was validated using a recent validation strategy based on accuracy profiles. Good results were obtained in terms of trueness, precision, and linearity in the following dosing ranges: from 0.77 to 200nmol/L for urine and from 0.48 to 100nmol/L for serum. The 95% reference range of serum hepcidin-25 concentration established after excluding known conditions that affect hepcidin-25 expression was 1.5 to 15.2nmol/L. A difference between genders was demonstrated with a median concentration of 5.5 versus 7.2nmol/L for women and men, respectively. Serum hepcidin-25 concentrations were strongly correlated with ferritin and, to a lesser extent, with iron levels. The coefficient of renal excretion ranged from 0.1 to 16.4%. Higher values of hepcidin-25 concentrations were observed on ethylene diamine tetraacetate tubes compared to serum or lithium-heparin devices.