Red cell alloimmunization is associated with development of autoantibodies and increased red cell transfusion requirements in myelodysplastic syndrome.

Up to 90% of patients with a myelodysplastic syndrome require red blood cell transfusion; nevertheless, comprehensive data on red cell alloimmunization in such patients are limited. This study evaluates the incidence and clinical impact of red cell alloimmunization in a large cohort of patients with myelodysplastic syndrome registered in the statewide South Australian-MDS registry. The median age of the 817 patients studied was 73 years, and 66% were male. The cumulative incidence of alloimmunization was 11%. Disease-modifying therapy was associated with a lower risk of alloimmunization while alloimmunization was significantly higher in patients with a revised International Prognostic Scoring System classification of Very Low, Low or Intermediate risk compared to those with a High or Very High risk (P=0.03). Alloantibodies were most commonly directed against antigens in the Rh (54%) and Kell (24%) systems. Multiple alloantibodies were present in 49% of alloimmunized patients. Although 73% of alloimmunized patients developed alloantibodies during the period in which they received their first 20 red cell units, the total number of units transfused was significantly higher in alloimmunized patients than in non-alloimmunized patients (90±100 versus 30±52; P<0.0001). In individual patients, red cell transfusion intensity increased significantly following alloimmunization (2.8±1.3 versus 4.1±2.0; P<0.0001). A significantly higher proportion of alloimmunized patients than non-alloimmunized patients had detectable autoantibodies (65% versus 18%; P<0.0001) and the majority of autoantibodies were detected within a short period of alloimmunization. In conclusion, this study characterizes alloimmunization in a large cohort of patients with myelodysplastic syndrome and demonstrates a signficant increase in red cell transfusion requirements following alloimmunization, most probably due to development of additional alloantibodies and autoantibodies, resulting in subclinical/clinical hemolysis. Strategies to mitigate alloimmunization risk are critical for optimizing red cell transfusion support.

Blood transportation for medical retrieval services.

INTRODUCTION: Medical retrieval services resuscitate and retrieve the critically ill and injured. Lifesaving treatment includes the transfusion of red blood cells (RBCs). To ensure patient safety and maximum therapeutic benefit for the patient, the transportation of RBCs for transfusion must occur under optimal conditions. Blood shippers currently in use in Australia are principally polystyrene containers, often selected for low cost, although performance validation is becoming increasingly important. The quality of the blood to the consumer may be compromised by the use of inappropriate shippers and transport systems. METHODS: A prototype of a user-friendly soft pack blood shipper was developed and tested in various climatic conditions over 24 hour periods with the RBC temperature monitored. RESULTS: The blood shipper was validated to maintain blood temperature within an acceptable range (2 degrees to 10 degrees C (35.6 degrees-50 degrees F) for up to 16 hours during transport of ambient temperatures ranging from 8 degrees to 35 degrees C. (46.4 degrees-95 degrees F). CONCLUSION: The blood shipper provides adequate storage for blood products under a range of climatic conditions and time periods adequate for most retrieval purposes. This allows optimal blood transport system for the medical retrieval service, helping to ensure maximum patient safety and therapeutic benefit from transfusion. The validated blood shipper is also important to blood banks and blood consumers for nonretrieval blood transportation.