Maternal red blood cell alloimmunisation in south western Uganda.

AIMS/OBJECTIVES: To identify the frequency and nature of maternal red blood cell (RBC) alloimmunisation in Uganda and to determine the prevalence of RhD negativity and the rate of RBC alloimmunisation in Ugandan pregnant women. BACKGROUND: Haemolytic disease of the foetus and newborn (HDFN) results from maternal alloimmunisation following exposure to allogeneic RBCs during pregnancy or blood transfusion. The prevalence of maternal RBC alloimmunisation in Ugandans is not known. MATERIALS AND METHODS: Pregnant women at Mbarara Hospital, South Western Uganda, were investigated in a cross-sectional study. Demographics, transfusion and obstetric histories were recorded. Maternal RBC alloimmunisation was demonstrated using immunohaematological techniques. RESULTS: A total of 2001 pregnant women were recruited; 3.6% of them being RhD negative. Forty-five women (2.2%; 95% CI: 1.6-2.9) were found to be alloimmunised to RBC antigens. There were 38 RBC alloantibodies of known specificity including anti-S, 12; anti-M, 11; anti-Le(a) , 6; anti-D, 4 and 1 each of anti-K, anti-Fy(b) , anti-Jk(a) , anti-Lu(a) and anti-Kp(a) . In two women (4.4%), there were antibody combinations (anti-M+S and anti-K+Kp(a) ). Obstetric history, gestational age and previous immunising events were not significantly associated with the rate of alloimmunisation. CONCLUSIONS: This study revealed a maternal RBC alloimmunisation rate of 2.2% which was comparable with findings from a Zimbabwean study where the prevalence was 1.7%. Given the 6·0% prevalence of anti-D among RhD-negative women in our study and the high immunogenicity of the D antigen, programmes for preventing anti-D alloimmunisation and HDFN in Uganda should be considered seriously.

Assessment of the clinical transfusion practice at a regional referral hospital in Uganda.

The aim of this study was to determine the indications for transfusion, blood ordering practices and post-transfusion complications, and to assess the clinical transfusion practice at Mbarara Regional Referral Hospital (MRRH) in Mbarara, Uganda. There are no guidelines on the appropriate use of blood at MRRH. Therefore, there was a need to assess the local clinical transfusion practice. Patients' hospital files were studied for evidence of blood transfusions in 2008. All five wards were reviewed and details on the transfusion process were recorded. A total of 1730 patients (median age, 19.0 years; range, 1 day to 88 years; female-to-male ratio, 1.4), for whom blood was cross-matched, were studied. Of these, 1674 (96.8%) patients actually received transfusions, which were as whole blood in 58.4% of recipients. The mean number of units per recipient was 1.7 and the cross-match-to-transfusion ratio was 1.3. The three most frequent indications for transfusion were malaria (38.8%), bleeding (27.1%) and other infections (16.1%). There were no records for pre-transfusion haemoglobin, compatibility testing, transfusion start-times and vital signs in 30.2, 51.8, 21.5 and 97.6% of the recipients, respectively. Transfusion reactions were recorded for 10 (0.6%) patients. Although there was no evidence of blood wastage, inadequacies were noted in the documentation of the transfusion process. There is a need to train staff in blood transfusion and to design a 'blood transfusion form' for easy monitoring and evaluation. A hospital transfusion committee and guidelines on the appropriate use of blood should be put in place at MRRH.

Prevalence and specificities of red blood cell alloantibodies in transfused Ugandans with different diseases.

BACKGROUND AND OBJECTIVES: Alloantibody formation against red blood cell (RBC) antigens is a common complication of transfusion therapy. However, the prevalence of RBC alloimmunization is hardly known in Black Africans. In Uganda, the practice is to transfuse ABO/D compatible blood without screening for immune antibodies. The aim of this study was to determine the prevalence and specificities of RBC alloantibodies in transfused Ugandans. MATERIALS AND METHODS: Using a cross-sectional design, transfused patients at Mulago Hospital in Kampala, Uganda were investigated. Demographic characteristics and transfusion histories were recorded. EDTA blood samples were obtained from consenting patients and RBC alloimmunization was demonstrated using immunohaematological tests. RESULTS: A total of 214 transfused patients (mean age, 30.3 years; F/M ratio, 1.0) were investigated. Thirteen patients (6.1%) possessed RBC alloantibodies whose specificities were six anti-E; three anti-S; one each of anti-D, -K and -Le(a); and two samples were pan-reactive. Eleven (84.6%) of the alloimmunized patients had experienced up to 10 transfusion episodes. The number of units of blood transfused and the transfusion episodes were significantly associated with the RBC alloimmunization rate (P = 0.01). CONCLUSIONS: The prevalence of RBC alloimmunization in transfused Ugandans was 6.1% and was associated with the number of donor exposures. This immunization rate is similar to that observed in transfused Caucasians despite differences in RBC antigen distributions. Patients with malaria were less likely to develop RBC alloantibodies. Alloantibodies were mainly against E and S antigens. We recommend the introduction of pretransfusion antibody tests in Uganda depending on the recipient's diagnosis.