Use of potassium adsorption filter for the removal of ammonia and potassium from red blood cell solution for neonates

Predictive Role of Reticulocyte Fluorescence for Late Red Blood Cell Transfusion in Very Low Birth Weight Infants

BACKGROUND

Nearly 58% of very low birth weight (VLBW) infants receive at least one red blood cell transfusion, which is not without risk. Reticulocyte fluorescence (RF) indicates the degree of cell maturation. The greater the fluorescence, the greater the immaturity of the reticulocytes.

AIM

To evaluate RF as a marker of reticulocyte maturity and to investigate its predictive value for transfusion requirement in VLBW infants.

METHODS

Complete blood count was performed at 1, 7, 14, 21, and 28 d of age in 104 VLBW infants at the University Hospital of Parma. Iron supplementation was started at 15 d of life. The infants were divided into two groups: those who required transfusion after 28 d of life. (Tr) and those who did not (NTr).

RESULTS

Twenty-seven of 104 newborns required a red blood cell transfusion after 28 d of life (Tr group). At 14 d of life, the percentage of high fluorescence reticulocyte (HFR) was significantly higher in the r group than in infants who did not receive any transfusion (NTr groups): 18.5 vs. 5%, p = 0.002. The ROC curve (AUC 74%) revealed an HFR cut-off value of 16.5% as a predictor of the need for red blood cell (RBC) transfusion.

CONCLUSIONS

Reticulocyte maturation at 14 d of life is clinically useful for estimating the qualitative impairment of erythropoiesis and predicts the risk of RBC transfusion in VLBW infants. The data suggest the need for tailored iron integration in VLBW infants to improve the quality of hematopoiesis and reduce the risk of blood transfusion.

Transfusion strategies for neonates: current perspectives

Background

Blood transfusion intervention has been proven to be a crucial therapeutic aid for preterm infants with serious morbidities such as sepsis, intraventricular hemorrhage, and cardiopulmonary insufficiencies. However, blood transfusion practices have also been shown to cause significant adverse outcomes, which may negate the therapeutic effect of the intervention. To address the varying policies regarding the administration of blood products, healthcare professionals have adopted a consensus-based approach. The absence of a standard protocol has resulted in conflicting outcomes in previous clinical studies.

Objective

This study aimed to evaluate the effectiveness of blood transfusion practices in preterm infants by analyzing past clinical research and identifying the current trends that have emerged as a result of recent trials.

Results

Recent trials have demonstrated comparable trends in mortality rates and other primary outcomes, including retinopathy of prematurity, intraventricular hemorrhage, bronchopulmonary dysplasia, and brain injury, following transfusion of blood products in both groups. Nevertheless, employing restrictive thresholds rather than adopting a liberal approach can reduce these outcomes.

Conclusion

The current literature does not provide clear support for either technique as opposing and contradictory results are evident. However, there is a slight inclination toward the restrictive transfusion threshold due to recent trials, which warrants further in-depth investigation into this issue.

Double-filtered leukoreduction as a method for risk reduction of transfusion-associated graft-versus-host disease

Background

Transfusion-associated graft-versus-host disease (TA-GvHD) is caused by leukocytes, specifically T cells within a transfused blood product. Currently, the prevention of transfusion-associated graft-versus-host disease is performed by irradiation of blood products. With a sufficient reduction of leukocytes, the risk for TA-GvHD can be decreased. With consistent advances in current state-of-the-art blood filters, we herein propose that double filtration can sufficiently reduce leukocytes to reduce the risk for TA-GvHD.

Materials

Thirty RBC concentrates were filtered with leukocyte filters, followed by storage at 1–6 ^oC for 72 hours, and then a second filtration was performed. Residual leukocytes in the double-filtered RBC units (n = 30) were assessed with flow cytometric methods, and an additional assay with isolated peripheral blood mononuclear cells (PBMCs) (n = 6) was done by both flow cytometric methods and an automated hematology analyzer. Quality of the RBCs after filtration was evaluated by hematological and biochemical tests. In vitro T cell expansion was performed using anti-CD3/CD28-coated Dynabeads or anti-CD3 (OKT3). In vivo experiment for GvHD was performed by using NOD.Cg-Prkdc^scid Il2rg^tm1Wjl/SzJ (NSG) mice.

Results

Double-filtered blood products showed residual leukocyte levels below detection limits, which calculated to be below 1200–2500 cells per blood unit. In vitro expansion rate of T cells showed that 6x10³ and 1x10³ cell-seeded specimens showed 60.8±10.6 fold and 10.2±9.7-fold expansion, respectively. Cell expansion was not sufficiently observed in wells planted with 1x10² or 10 cells. In vivo experiments showed that mice injected with 1x10⁵ or more cells cause fatal GvHD. GvHD induced inflammation was observed in mice injected with 1x10⁴ or more cells. No evidence of GvHD was found in mice injected with 10³ cells.

Conclusions

Our study suggests that additional removal of contaminating lymphocytes by a second leukodepletion step may further reduce the risk for TA-GvHD.