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ArtinM, a D-mannose binding lectin from Artocarpus heterophyllus, has immunomodulatory activities through its interaction with N-glycans of immune cells, culminating with the establishment of T helper type 1 (Th1) immunity. This interaction protects mice against intracellular pathogens, including Leishmania major and Leishmania amazonensis. ArtinM induces neutrophils activation, which is known to account for both resistance to pathogens and host tissue injury. Although exacerbated inflammation was not observed in ArtinM-treated animals, assessment of neutrophil responses to ArtinM is required to envisage its possible application to design a novel immunomodulatory agent based on carbohydrate recognition. Herein, we focus on the mechanisms through which neutrophils contribute to ArtinM-induced protection against Leishmania, without exacerbating inflammation. For this purpose, human neutrophils treated with ArtinM and infected with Leishmania major were analyzed together with untreated and uninfected controls, based on their ability to eliminate the parasite, release cytokines, degranulate, produce reactive oxygen species (ROS), form neutrophil extracellular traps (NETs) and change life span. We demonstrate that ArtinM-stimulated neutrophils enhanced L. major clearance and at least duplicated tumor necrosis factor (TNF) and interleukin-1beta (IL-1β) release; otherwise, transforming growth factor-beta (TGF-β) production was reduced by half. Furthermore, ROS production and cell degranulation were augmented. The life span of ArtinM-stimulated neutrophils decreased and they did not form NETs when infected with L. major. We postulate that the enhanced leishmanicidal ability of ArtinM-stimulated neutrophils is due to augmented release of inflammatory cytokines, ROS production, and cell degranulation, whereas host tissue integrity is favored by their shortened life span and the absence of NET formation. Our results reinforce the idea that ArtinM may be considered an appropriate molecular template for the construction of an efficient anti-infective agent.

MMA can be used to evaluate the ability of RBC autoantibodies to mediate overt hemolysis. It can be especially useful to determine the role played by cold and warm auto-antibodies in mixed auto-immune hemolytic disease, helping to define the best treatment option.

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Background and Objectives Antibodies of unknown specificity (AUS) are frequently identified in the pre‐transfusion testing. These antibodies can be insignificant or potentially cause post‐transfusion haemolysis. Information about the prevalence of clinically relevant AUS is still lacking. Our aim was to predict the potential clinical relevance of AUS using the monocyte monolayer assay (MMA) and to identify the clinical and laboratorial determinants of AUS’ significance. Materials and Methods Antibodies of unknown specificity identified at a single institution from 2015–2017 were evaluated through MMA. A monocyte index (MI) of more than 5% was predictive of potential post‐transfusion haemolysis. Results Thirty‐two patients with AUS were included in the study. Of the studied AUS, 37·5% (12/32) presented with a monocyte index (MI) more than 5%. In the group of significant AUS, 41·7% of the patients presented with sickle cell disease (SCD) and the AUS were associated with Rh antibodies in 75% of the cases. In the group of insignificant AUS, only 10% of the patients had SCD and the association with Rh antibodies was detected in 20% of the cases. The presence of Rh antibodies was independently associated with the AUS clinical relevance (P = 0·012). Conclusion More than one‐third of the AUS are potentially clinically relevant, and the association with Rh antibodies is predictive of AUS relevance. Services must honour AUS in the pre‐transfusion process in order to ensure transfusion safety.

Background The genetic diversity of the RHCE gene locus has been explored in diverse populations of different racial backgrounds. Data referring to the diversity of RHCE encoding weakened expression of C, c, E, and e in multiethnic populations is still incomplete. Methods Samples from Brazilian blood donors presenting reduced expression of C, c, E, or e on gel method were selected for the study. All exons and flanking introns of RHCE were genotyped though direct Sanger sequencing for the included donors. Results Sixty‐six donors were included: 23 with weak C, 22 with weak c, 6 with weak E, 14 with weak e, and 1 with weak c and E. Among the samples with weak C, the following altered RH*C were encountered: RHCE*CeMA (n = 3), RHCE*Ce941C (n = 1), and RHCE*CeVA (n = 1). RHD*D‐CE(4–7)‐D was detected in six cases, RHCE*CE was presumably present in five cases, and seven cases were unexplained. Two altered alleles underlay the weak c phenotype: RHCE*ceJAL (n = 20) and RHCE*ce340T (n = 2), and two altered RHCE justified weak e: RHCE*ceMO (n = 6) and RHCE*ceJAL (n = 8). Three variant RHCE were associated with weak E: RHCE*cEJU (n = 4), RHCE*cE382C (n = 1), and RHCE*cEIV (n = 1). The RHCE*cE905A justified one case of weak c and E. Conclusion We describe the distribution of RHCE variants found in association with weak expression of C, c, E, and e in blood donors of multiethnic origin, which differs in comparison to that previously reported for people of African or Caucasian descent.

This report regards a 40-year-old man, diagnosed with sickle cell anaemia (SCA; HbSS), who was admitted to our emergency service with symptoms of vaso-occlusive crisis. The patient was not under chronic transfusion therapy, and the baseline haemoglobin was 7 g/dL. He was initially treated with opioid analgesics and hydration. The initial laboratory investigation showed Hb = 7.1 g/dL, Ht = 21.1%, lactate dehydrogenase (LDH) = 384 U/L, total bilirubin = 2.3 mg/dL and indirect bilirubin = 1.32 mg/dL. Anti-E and anti-Di a were identified in the antibody screening using the gel method (ID-DiaPanel and ID-DiaPanel-P, BIORAD, Lagoa Santa, Brazil). Previous immunohaematological investigation had shown only anti-E. He was transfused with two red blood cell (RBC) units (254 and 261 mL), without any clinical intercurrences during the infusion. The patient's phenotype was R 0 r; K−; Jk(a + b−); Fy(a + b−); S−, s+ and Dia−, and the transfused units had the same phenotype. In addition, molecular investigation for the most common RHD 1 and RHCE variants (Restriction Fragment Length Polymorphism-RFLP-PCR designed to detect c.733C>G) was performed and was negative. All transfused units were HbS-negative, and the patient's blood volume was 4.5 L. The laboratory tests performed approximately 8 hours after the transfusion revealed a sharp decrease in the haemoglobin levels (posttransfusion Hb = 5 g/dL) and an increase in LDH (550 U/L). Parvovirus polymerase chain reaction was performed and was negative.

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