Journal of Blood Disorders & Transfusion

Abstract

Extended RBC Phenotype Matching Reduces the Incidence of Alloimmunization in Patients with Warm Autoimmune Haemolytic Anaemia (wAIHA)

Chih-Chien Shao and Denise E. Jackson*

Background: Warm Autoimmune Haemolytic Anaemia (wAIHA) involves autoantibodies destroying red blood cells, often necessitating transfusions. Alloimmunization, the formation of antibodies against non-self-Red Blood Cells (RBC) antigens, complicates future transfusions. This review evaluates whether extended RBC phenotype matching reduces alloimmunization compared to standard ABO and Rh matching.

Methods: Databases (PubMed, Scopus, Cochrane Library and Google Scholar) were searched for studies (2014- 2024) on wAIHA patients comparing basic, partial and full extended RBC phenotype matching. Eligible data were analysed using a random-effects model to assess alloimmunization risk reduction. Manual searches were performed using relevant references.

Results: Ten studies, both retrospective and prospective, were included. Basic matching (ABO and Rh) had the highest alloimmunization rate at 32.8% (95% CI: 13.3%-52.2%; I²=95.79%, p<0.001). Partial matching (Rh and Kell) reduced rates to 22.5% (95% CI: 10.4%-34.6%; I²=49.57%, p=0.046), while full matching lowered it to 11.6% (95% CI: 4.5%18.7%; I²=73.65%, p=0.001). Despite heterogeneity, results consistently showed extended matching reduced alloimmunization.

Conclusion: Extended RBC phenotype matching significantly lowers alloimmunization risk in wAIHA patients, particularly in chronically transfused cases. However, the variability across studies highlights the need for standardised transfusion practices and further research to confirm these results through larger, randomised controlled trials.

Published Date: 2024-12-13; Received Date: 2024-11-13