Cost‐effectiveness of implementing molecular immunohematology

Abstract

BackgroundMolecular immunohematology is practised in clinical laboratories and blood centres. It is based on red cell genotyping, which is a technology whereby DNA‐based techniques are used to evaluate genes for the particular single and multiple nucleotide substitutions, deletions, insertions and gene conversions that determine the expression of red cell antigens. Fetal red cell genotyping, and in particular RHD genotyping, using the discarded cell pellet of amniotic fluid was developed some 20 years ago. It replaced the need for fetal blood sampling and also can determine paternal zygosity with better certainty. Cell‐free fetal DNA in maternal plasma is now the non‐invasive (fetal) alternative to amniotic fluid as the biological material of choice. It is being used in Europe to reduce the exposure of Rh immune globulin for the routine Rh‐negative pregnancy. RHD genotyping is used to determine zygosity and resolve weak D antigen discrepancies as a cost equivalent alternative to the administration of Rh immune globulin. Since then, a plethora of data has accumulated on the value of screening donors for rare blood types. For common antigens, red cell genotyping as an historical test‐of‐record will create efficiencies in the labelling of antigen‐negative blood if care is taken in testing appropriate repeat donors. Certainly, it has been shown that exposing antigen‐negative types through the entire supply chain replaces shipping from a central facility.ConclusionMolecular immunohematology is not the implementation of cost reductions but the recognition of ‘effective’ processes and algorithms that incorporate molecular testing to provide tangible benefits to pregnant women and transfusion recipients.