Article

Immunisation anti-érythrocytaire dans les hémoglobinopathies : à propos de 84 cas

UR 99/UR/08-33, faculté de médecine, université de Sfax, Sfax, Tunisie. Electronic address: .
Transfusion Clinique et Biologique (Impact Factor: 0.67). 12/2012; 19(6):345–352. DOI: 10.1016/j.tracli.2012.06.006

ABSTRACT AimsTo estimate the rate of red cell immunization in hemoglobinopathies.Patients and methodsProspective study (1990–2009) about 84 patients: 44 homozygous sickle cell anemia, one heterozygous sickle cell anemia S/C, 30 thalassemia and nine sickle cell anemia-thalassemia. The mean age was 10.13 years (extremes: 1–45). The red cell units transfused were ABORH1 compatible, then RH-KELL phenotyped after 2006 and phenocompatible after alloimmunisation. The cross-match was realized using indirect antiglobuline test. Irregular red cell antibody screening was realized before every transfusional episode and the direct antiglobuline test was done when there was a poor transfusional efficiency.ResultsThe number of red blood cells units transfused was 3545 (42.2/patient). The number of red cell antibody screening and the number of direct antiglobulin test were respectively 1474 (17.5/patient) and 272 (3.2/patient). Twenty-seven antibodies were identified (32.1%): 14 alloantibodies (16.6%, 16.6% in sickle cell disease, 16.6% in thalassemia, P = 1), 16 antoantibodies (19.04%, 11.1% in sickle cell disease, 33.3% in thalassemia, P = 0.018). There were three cases of association of allo- and autoantibodies. The most frequent alloantibodies were anti-RH3 and anti-KEL1 and were developed after transfusion of standard red cell units. There was no significant relation, neither between sex and risk of immunization, nor between the number of red cell units transfused and alloimmunization. On the other hand, there was a significant relation between autoimmunization and the number of red cell units transfused in thalassemia (P < 0.001).Conclusion
This study proves the interest of using RH-KELL red cell units compatible in patients with hemoglobinopathies in order to reduce alloimmunisation rates.

1 Follower
 · 
54 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: The search for genetic determinants of alloimmunization in sickle cell disease transfusion recipients was based on two premises: i) that polymorphisms responsible for stronger immune and/or inflammatory responses and hemoglobin β(S) mutation were co-selected by malaria; and ii) that stronger responder status contributes to development of lupus. We found a marker of alloimmunization in the gene encoding for Ro52 protein, also known as Sjögren syndrome antigen 1 (SSA1) and TRIM21. Surprisingly, the nature of the association was opposite of that with lupus; the same variant of a polymorphism (rs660) that was associated with lupus incidence was also associated with induction of tolerance to red blood cell antigens during early childhood. The dual function of Ro52 can explain this apparent contradiction. We propose that other lupus/autoimmunity susceptibility loci may reveal roles of additional molecules in various aspects of alloimmunization induced by transfusion as well as during pregnancy.
    Transfusion Medicine and Hemotherapy 11/2014; 41(6):436-45. DOI:10.1159/000369145 · 2.01 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To study the clinical and biological profile of β-thalassemic patients in our region, reflecting the quality of their care. A retrospective study (2010-2011) on 26 β-thalassemic patients followed in the pediatrics service at CHU Farhat Hached Sousse, Tunisia. Epidemiological, clinical and biological data were collected from medical records and transfusion files of patients. The transfusion protocol adopted was to maintain a hemoglobin level>10g/dL by regular transfusions every 3-4 weeks. Iron chelation therapy, in order to maintain serum ferritin<1500ng/mL, was introduced when serum ferritin exceeded 800-1000ng/mL. The mean age of patients at diagnosis was 15 months. The clinical impact of anemia had resulted in failure to thrive in 54% of patients and facial dysmorphism in 23%. The average transfusion requirement was estimated at 311.02mL/kg/year with 6 cases of hyperconsumption. The immunohaematological monitoring showed the appearance of anti-RBC alloimmunization in one patient and 4 cases of autoimmunization. Poor adherence of chelation therapy was 62% and causing 5 cases of cardiac complications, 4 cases of liver injury and 14 cases of endocrine complications. Improving the therapeutic care of β-thalassemic children requires better monitoring of transfusion recovery and improved adherence to chelation therapy. Copyright © 2014 Elsevier Masson SAS. All rights reserved.
    Transfusion Clinique et Biologique 11/2014; 21(6). DOI:10.1016/j.tracli.2014.10.002 · 0.67 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Evaluate the anti-erythrocyte and anti-HLA immunization rates in hemoglobinopathies. Cross-sectional study (October 2009-March 2010) on 83 patients followed for hemoglobinopathies. The irregular antibodies research is realized by two techniques: indirect Coombs and enzymatic technique on gel cards. The search for anti-HLA class I antibodies is done by complement dependent lymphocytotoxicity. The mean age was 30 years (14-64 years), the sex ratio M/F is 0.84. Our series included 42 cases of sickle cell disease (29 homozygous sickle cell anemia and 13 sickle-thalassemia) and 41 cases of thalassemia syndromes (26 major and 15 intermediate). The anti-erythrocyte alloimmunization rate is 10.84% without difference between thalassemia syndromes and sickle cell disease. The autoimmunization rate (22.89%) is higher in thalassemia syndromes (41.46%) than in the sickle cell disease (7.14%) (P<0.001). The anti-HLA immunization rate is 31.6% without difference between thalassemia syndromes and sickle cell disease. The young age, transfusion at a young age and the total number of transfusions are the factors that increase the risk of anti-erythrocyte autoimmunization. No clinicobiological parameter does influence the anti-erythrocyte and anti-HLA alloimmunization. There is no significant association between anti-erythrocyte and anti-HLA immunization. The erythrocyte and anti-HLA anti-immunization rates are high in our series. Preventive strategy is needed to ensure optimal blood safety. Copyright © 2014 Elsevier Masson SAS. All rights reserved.
    Transfusion Clinique et Biologique 10/2014; 21(6). DOI:10.1016/j.tracli.2014.10.003 · 0.67 Impact Factor