Red cell alloimmunization in haemato-oncology patients transfused with packed red blood cells extended phenotype matched for Rh and Kell antigens versus the standard crossmatched units

Background and Objectives

There is limited evidence regarding the advantage of transfusing extended phenotype-matched (EPM) packed red blood cells (PRBCs) to prevent alloimmunization in haemato-oncology patients. This randomized control trial aimed to determine the alloimmunization in haemato-oncology patients transfused with PRBCs which are EPM for Rh (C, E, c, e) and Kell (K) antigens (group I) versus those receiving standard compatible PRBCs (group II).

Materials and Methods

Patients having a negative antibody screen (ABS), direct antiglobulin test (DAT) and autologous control (AC) were randomly allocated to either group I or II (n = 50 each). A follow-up (FU) testing post-transfusion was conducted for haemoglobin (Hb), ABS and DAT at 1 week, 1 month and 3 months. ABS was conducted using fully automated immunohaematology analyser, while DAT, compatibility testing and extended phenotyping were conducted manually using column agglutination technique.

Results

There was no significant difference between the two groups with respect to mean (±SD) Hb at initial enrolment (group I, 5·06 ± 1·29 g/dl and group II, 5·41 ± 1·37 g/dl; P = 0·179), age (40 ± 17·3 years v/s 42·2 ± 17·2 years; P = 0·523), gender (P = 0·835) and diagnosis (P = 0·06). All patients in group I and II had negative ABS, DAT and AC at all three FUs. Group II patients were transfused more PRBCs (372 v/s 187, P = 0·000), while the mean Hb increment between successive FU was significant in both the groups (P = 0·003).

Conclusion

It appears that there is no added benefit of providing EPM PRBCs in haemato-oncology patients, as none developed RBC alloantibodies.