Alloimmunization in Patients With Sickle Cell Disease and Thalassaemia: Experience of Single Centre From Oman

Abstract

BackgroundBlood transfusion is an integral part of the supportive care for patients with sickle cell disease (SCD) and thalassaemia. The hazard of red cell alloimmunization, however, is one of the main complications of this therapy.ObjectivesThe aim of this study was to evaluate the prevalence of red cell alloimmunization in Omani patients with sickle cell anaemia and thalassemia.MethodsThis study included 262 patients whose historical transfusion records were available. One hundred and twenty-nine patients with thalassaemia who were attending the day care unit for regular transfusions, and 133 SCD patients admitted at our hospital were included in this study. The Diamed® gel system was used for the screening and identification of atypical antibodies.ResultsThe rate of alloimmunization in SCD patients was 31.6% (n=42, 95%CI, 24.87–40.66), whereas in patients with thalassaemia it was 20% (n=26; 95%CI, 13.9–27.6). Antibodies to E, e, C, c, D, K, S, Fyª, Kpª, Jkª and Cw were observed; 85% of the patients were also immunised with Rh and Kell antigens. Considering the two groups together, 8 developed nonspecific antibodies and 12 developed more than one antibody.ConclusionsRed cell transfusions were associated with a significant risk of alloimmunization. It is, therefore, imperative to perform an initial extended red cell phenotyping for both donors and recipients, and carefully select ABO, Rh and Kell matched donors. The higher incidence of alloimmunization in SCD patients is related to the inherent SCD-specific inflammatory state.

Frequency of Red Blood Cell Alloimmunization in Patients with Sickle Cell Disease in Palestine

“…Of all alloantibodies detected, anti-K (33.3%) was the most frequent alloantibody followed by anti-E (22.2%), anti-D (11.1%), anti-C (11.1%), and anti-c (11.1%), respectively. Given that both Rh and Kell systems have highly immunogenic antigens and phenotype-matched RBC was not performed for these antigens except D, the prevalence of alloantibodies of both systems among our study subjects was similar to previous reports [ 9 , 10 , 13 – 16 , 19 ]. Donor RBC phenotyping for Rh (D, C, E, c, and e) and K 1 (partial phenotype matching) is necessary to avoid alloimmunization and stop unwanted clinical consequences in SCD patients [ 25 ].…”

“…Thus, this study aimed to investigate the frequency of alloimmunization among these patients. The rate of alloimmunization observed in the present study was 7.76%, which is lower than that reported in many studies of RBC alloimmunization in SCD patients [ 10 , 12 – 15 , 19 , 23 – 25 ]. Other studies present lower rates of RBC alloimmunization [ 16 , 26 – 28 ].…”

“…Castro et al reported a drop in the rate of alloimmunization from 3% to 0.5% when SCD patients were transfused only with phenotype-matched RBC [ 29 ]. Anti-D was found in two SCD patients (22.2%) where in one case it was a single alloantibody and in the second case it was in combination with anti-C, a frequency higher than that reported in most studies [ 14 – 16 , 19 ]. The two patients with anti-D were males, the first patient was 8 years old and the other patient with the anti-D and anti-C aged 54 years.…”

“…Alloimmunization has been associated with increased morbidity in SCD, due to the difficulty in cross-matching to find compatible blood for future transfusion, autoantibody formation, hemolysis, and delayed transfusion reactions [ 15 , 18 ]. The most frequently reported alloantibodies identified in SCD are those directed against antigens of the Rh and Kell systems, followed by the Kidd and Duffy systems [ 9 , 10 , 13 – 16 , 19 ]. Blood transfusion in Palestine takes place in both public and private hospitals, which are all governed by the guidelines and directions of the Palestinian Ministry of Health (MOH) on blood bank issues.…”

The Shape Shifting Story of Reticulocyte Maturation

“…Observational studies conducted on random patients who received incidental transfusions demonstrated 1–3% alloimmunization. However, in patients with sickle cell disease (SCD) who receive chronic transfusions this can increase to 8% or even as high as 76% ( Campbell-Lee and Kittles, 2014 ; Alkindi et al, 2017 ). In severe cases the only option available for the patient is a stem cell transplantation, which carries significant risk on its own.…”