Packed red blood cell transfusion in preterm infants

RBC transfusion and necrotizing enterocolitis in very preterm infants: a multicenter observational study

The causal relationship between Packed red blood cell (RBC) transfusion and necrotizing enterocolitis (NEC) remains uncertain. This study aims to provide an exploration of transfusion and NEC in very preterm infants. Using data from the Chinese Neonatal Network cohort study between 2019 and 2021, the analysis focused on very preterm infants (with a birth weight of < 1500 g or a gestational age of < 32 weeks) who developed NEC after receiving transfusions. The time interval between the prior transfusion and NEC was analyzed. An uneven distribution of the time interval implies an association of transfusion and NEC. Additionally, multivariable logistic analysis was conducted to detect the prognosis of defined transfusion-associated NEC(TANEC). Of the 16,494 infants received RBC transfusions, NEC was noted in 1281 (7.7%) cases, including 409 occurred after transfusion. Notably, 36.4% (149/409) of post-transfusion NEC occurred within 2 days after transfusion. The time interval distribution showed a non-normal pattern (Shapiro-Wilk test, W = 0.513, P < 0.001), indicating a possible link between transfusion and NEC. TANEC was defined as NEC occurred within 2 days after transfusion. Infants with TANEC had a higher incidence of death (adjusted OR 1.69; 95% CI 1.08 to 2.64), severe bronchopulmonary dysplasia (adjusted OR 2.03; 95% CI 1.41 to 2.91) and late-onset sepsis (adjusted OR 2.06; 95% CI 1.37 to 3.09) compared with infants without NEC after transfusion. Unevenly high number of NEC cases after RBC transfusions implies transfusion is associated with NEC. TANEC is associated with a poor prognosis. Further research is warranted to enhance our understanding of TANEC.

Hyper high haemoglobin content in red blood cells and erythropoietic transitions postnatally in infants of 22 to 26 weeks' gestation: a prospective cohort study

OBJECTIVE

Blood cell populations, including red blood cells (RBC) unique to the extremely preterm (EPT) infant, are potentially lost due to frequent clinical blood sampling during neonatal intensive care. Currently, neonatal RBC population heterogeneity is not described by measurement of total haemoglobin or haematocrit. We therefore aimed to describe a subpopulation of large RBCs with hyper high haemoglobin content, >49 pg (Hyper-He) following EPT birth.

DESIGN

Prospective observational cohort study.

SETTING

Two Swedish study centres.

PARTICIPANTS

Infants (n=62) born between gestational weeks 22+0 to 26+6.

METHODS

Prospective data (n=280) were collected from March 2020 to September 2022 as part of an ongoing randomised controlled trial. Blood was sampled from the umbilical cord, at postnatal day 1-14, 1 month, 40 weeks' postmenstrual age and at 3 months' corrected age.

RESULTS

At birth, there was a considerable inter-individual variation; Hyper-He ranging from 1.5% to 24.9% (median 7.0%). An inverse association with birth weight and gestational age was observed; Spearman's rho (CI) -0.38 (-0.63 to -0.07) and -0.39 (-0.65 to -0.05), respectively. Overall, Hyper-He rapidly decreased, only 0.6%-5.0% (median 2.2%) remaining 2 weeks postnatally. Adult levels (<1%) were reached at corresponding term age.

CONCLUSION

Our results point to gestational age and birth weight-dependent properties of the RBC population. Future work needs to verify results by different measurement techniques and elucidate the potential role of differing properties between endogenous and transfused RBCs in relation to neonatal morbidities during this important time frame of child development.

TRIAL REGISTRATION NUMBER

NCT04239690.

New insights into intestinal macrophages in necrotizing enterocolitis: the multi-functional role and promising therapeutic application

Necrotizing enterocolitis (NEC) is an inflammatory intestinal disease that profoundly affects preterm infants. Currently, the pathogenesis of NEC remains controversial, resulting in limited treatment strategies. The preterm infants are thought to be susceptible to gut inflammatory disorders because of their immature immune system. In early life, intestinal macrophages (IMφs), crucial components of innate immunity, demonstrate functional plasticity and diversity in intestinal development, resistance to pathogens, maintenance of the intestinal barrier, and regulation of gut microbiota. When the stimulations of environmental, dietary, and bacterial factors interrupt the homeostatic processes of IMφs, they will lead to intestinal disease, such as NEC. This review focuses on the IMφs related pathogenesis in NEC, discusses the multi-functional roles and relevant molecular mechanisms of IMφs in preterm infants, and explores promising therapeutic application for NEC.

Using umbilical cord blood as a source of paediatric packed red blood cells: Processing and quality control

BACKGROUND AND OBJECTIVES

Umbilical cord blood (UCB) has been used as a source of red blood cells (RBCs) for neonatal/paediatric transfusion purposes. This study adopted two different procedures to obtain umbilical RBC (U-RBC) to compare its quality control parameters to those of fractionated adult RBC (A-RBC), for paediatric purposes.

MATERIALS AND METHODS

UCB units (24) were filtered and processed based on two different methods, namely, conventional/manual (P1;n12) and automatic (P2;n12). They were compared to five fractionated A-RBCs. U-RBC and A-RBC were stored for 14 days and had their haematological, biochemical, haemolytic and microbiological parameters analysed at D1, D7 and D14. Cytokines and growth factors (GFs) in residual U-RBC plasma were measured.

RESULTS

Mean volume of processed U-RBC units was 45 mL for P1 and 39 mL for P2; the mean haematocrit level reached 57% for P1 and 59% for P2. A-RBC recorded a mean volume of 44 mL. Haematologic and biochemical parameters analysed in U-RBC and A-RBC presented similar behaviours during storage time, except for parameter values, which differed between them. Pro-inflammatory and immunomodulatory cytokines, as well as GFs, were higher in U-RBC residual plasma than in that A-RBC.

CONCLUSION

UCB can be processed into RBC based on either manual or automated protocols. U-RBC units met the referenced quality parameters defined for A-RBC. Some features, mainly the biochemical ones, should be further investigated to help improve quality parameters, with emphasis on differences found in, and particularities of, this material and on recipients of this new transfusion practice.