Alloimmunization in transfused patients with constitutional anemias in Norway.

BACKGROUND AND OBJECTIVES: The status of red blood cell alloimmunization in patients with constitutional anemias including hemoglobinopathies is not known in Norway. The study objective was to investigate the impact of a strategy based on phenotype-matching for C, c, E, e, K, Jka, Jkb, Fya, Fyb, S and s on alloimmunization. MATERIALS AND METHODS: We reviewed transfusions of 40 patients retrospectively using the computerized blood bank management system and medical records; including diagnosis, age at start of transfusion therapy, gender, number and age of packed red blood cell units transfused, follow-up time, phenotypes of the donors and patients, antigen-negative patients exposed to antigen-positive packed red blood cell units, transfusion reactions and alloantibody specificities. RESULTS: Forty patients received 5402 packed red blood cell units. Alloimmunization frequency was 20 % for the whole group, being 7%, 25 % and 30 % in patients with sickle cell disease (n = 14), thalassemia (n = 16) and other conditions (n = 10), respectively. The alloantibodies detected were anti-E, -c, -C, -Cw, -K, -Jka and -Lua. CONCLUSION: Good communication between the clinicians and the transfusion services is essential for successful management of patients with constitutional anemias. Providing full phenotype-matched units was not always possible. Extended pheno-/genotyping before the first transfusion and providing antigen-negative units for antigen-negative patients for at least C, c, E and K in every red cell transfusion would probably have reduced the alloimmunization rate. Non-phenotype-matched transfusions seem to be the main reason for alloimmunization. Finding markers for identifying responders prone to alloimmunization will ensure targeted transfusion strategies.

Red blood cell transfusion at Ullevål University Hospital--indications, consumption and blood group immunisation.

BACKGROUND: Knowledge of clinical transfusion practice should be improved to ensure that therapy is optimally effective, to avoid waste of resources and to ensure a safe supply of blood. MATERIAL AND METHOD: All patients who received a transfusion of red blood cell concentrate at Ullevål University Hospital in two 14-day periods in 2003 were included. Diagnoses, haemoglobin values and intervention codes were recorded from the patient records for which consent to access had been given. Blood samples were taken from consenting survivors to be tested for blood group immunisation. RESULTS: 348 patients were included. The median age was 62.8 years. They were given 1,162 concentrates in 471 transfusion episodes, of which 373 (79 %) consisted of one or two concentrates. As at 1 February 2009, 181 patients (52 %) were registered as having died. Access was possible to the records of 218 patients. The primary diagnosis was cancer for 76 patients (35 %), injuries for 36 (17 %) and cardiovascular disease for 34 (16 %). The transfusion was given to 89 (41 %) of patients in connection with a surgical intervention during the period covered by the patient records. A note about the transfusion was lacking in 46 (21 %) of the records. Transfusions were given to 52 patients whose haemoglobin concentration was above a threshold level of ≥ 8 g/100 ml (43 % of the patients). Blood group immunisation was found in one (3 %) of 38 survivors. INTERPRETATION: Red blood cell transfusion is most commonly given to elderly patients with chronic disorders and uncertain long-term prognoses. The clinical documentation is not infrequently incomplete. There is probably scope for a reduction in consumption if indications are based more on established scientific evidence and well-defined transfusion protocols. Blood group immunisation is not a frequent complication.