Transfusing selected RhD negative patients with RhD positive packed red cell concentrates resulted in lower frequency of anti-D development and saved almost two thousand RhD negative concentrates during 5 years.

BACKGROUND

The Blood Bank at Oslo University Hospital implements restrictions when the stocks of blood groups O and A RhD negative packed red blood cell concentrates (PRBCCs) drop below 60 units due to high demand and low donor availability. Restrictions entail transfusing RhD negative male patients and women >50 years with RhD positive units, to provide RhD negative units to those who should not receive RhD positive units. Earlier studies have reported that up to 50% of RhD negative patients developed anti-D after RhD positive blood transfusion. We aimed to investigate the rate of anti-D alloimmunization using this restriction strategy in our population.

STUDY DESIGN AND METHODS

This retrospective study was performed at Oslo University Hospital between 2006 and 2011. Antibody screen results were included throughout 2019 for the patients readmitted to the hospital.

RESULTS

607 RhD negative mostly cancer patients and patients having surgery for cardiovascular conditions received 1926 RhD positive PRBCCs. Post-transfusion antibody screen was available for 401 patients (66.1%), and 76 patients (22.2%) developed anti-D. In 15 of the 76 patients (19.7%), anti-D became evanescent in the follow-up.

DISCUSSION

The proportion of anti-D immunisation in RhD negative patients receiving RhD positive PRBCCs in this study was consistent with findings from other reports. To our knowledge, this is the first study reporting a high proportion of evanescence of anti-D. Transfusing selected RhD negative patients with RhD positive PRBCCs when RhD negative stocks are low, contributed saving 1926 RhD negative PRBCCs during the study period of 64 months.