Necrotizing enterocolitis and mortality after transfusion of ABO non-identical blood.

BACKGROUND: The relationship between ABO non-identical transfusion and the outcomes of necrotizing enterocolitis (NEC), and all-cause mortality in very-low birth weight (VLBW) neonates receiving red blood cell transfusion is unknown. STUDY DESIGN AND METHODS: A retrospective multicenter cohort study was conducted in VLBW neonates in neonatal intensive care units between 2004 and 2016. VLBW (≤1500 grams) neonates were followed until discharge or in-hospital death. The primary exposure was ABO group. Secondary exposures included platelet count, plasma transfusions, and maternal ABO group. Outcome measures were NEC (defined as Bell stage ≥ 2) and all-cause mortality. Time-dependent Cox regression models with competing risks were used to investigate factors associated with NEC and mortality. RESULTS: Thousand and sixteen neonates were included with 10.8% developing NEC (n = 110) and 14.1% mortality (n = 143). Platelet count (hazard ratio [HR] = 0.995; 95% confidence interval [CI]: 0.922-0.998) and number of plasma transfusions (HR = 2.908; 95% CI:1.265-6.682) were associated with NEC, while ABO group (non-O vs. O) was not (HR = 0.761; 95% CI: 0.393-1.471). Higher all-cause mortality occurred in neonates without NEC who were non-O compared with O (HR = 17.5; 95% CI: 1.784-171.692), but not in neonates with NEC (HR = 1.112; 95% CI: 0.142-8.841). Plasma transfusion was associated with increased mortality in both groups. DISCUSSION: ABO non-identical transfusion was not associated with NEC or mortality in neonates with NEC. It was associated with increased mortality in neonates without NEC. As many neonatal intensive care units transfuse only O group blood as routine practice, future trials are needed to investigate the association between this practice and neonatal mortality.

Utilising red cell antigen genotyping and serological phenotyping in sickle cell disease patients to risk-stratify patients for alloimmunisation risk.

BACKGROUND: Alloimmunisation and haemolytic transfusion reactions (HTRs) can occur in patients with sickle cell disease (SCD) despite providing phenotype-matched red blood cell (RBC) transfusions. Variant RBC antigen gene alleles/polymorphisms can lead to discrepancies in serological phenotyping. We evaluated differences between RBC antigen genotyping and phenotyping methods and retrospectively assessed if partial antigen expression may lead to increased risk of alloimmunisation and HTRs in SCD patients at a tertiary centre in Canada. METHODS: RBC antigen phenotyping and genotyping were performed by a reference laboratory on consenting SCD patients. Patient demographic, clinical and transfusion-related data were obtained from a local transfusion registry and chart review after research ethics board approval. RESULTS: A total of 106 SCD patients were enrolled, and 91% (n = 96) showed additional clinically relevant genotyping information when compared to serological phenotyping alone. FY*02N.01 (FY*B GATA-1) (n = 95; 90%) and RH variant alleles (n = 52, 49%; majority accompanied by FY*02N.01) were common, the latter with putative partial antigen expression in 25 patients. Variability in genotype-phenotype antigen prediction occurred mostly in the Rh system, notably with the e antigen (kappa: 0.17). Fifteen (14.2%) patients had a history of alloimmunisation, with five having HTR documented; no differences in clinical outcomes were found in patients with partial antigen expression. Genotype/extended-phenotype matching strategies may have prevented alloimmunisation events. CONCLUSION: We show a high frequency of variant alleles/polymorphisms in the SCD population, where genotyping may complement serological phenotyping. Genotyping SCD patients before transfusion may prevent alloimmunisation and HTRs, and knowledge of the FY*02N.01 variant allele increases feasibility of finding compatible blood.