El Kababi S, Benajiba M, El Khalfi B, Hachim J, Soukri A
Laboratory of Physiopathology, Genetics Molecular and Biotechnology (PGMB), Faculty of Sciences Ain Chock, Research Center Health and Biotechnology, University Hassan II of Casablanca, Km 8 Route El jadida, BP 5366, Mearif, 20100 Casablanca, Morocco.
National Blood Transfusion Center, Immuno-hematology, Bab-El-Irfane, rue m'fadel-Cherka, 10000 Rabat, Morocco.
Transfus Clin Biol. 2019 Nov;26(4):240-248. doi: 10.1016/j.tracli.2019.06.004. Epub 2019 Jun 19.
Red blood cell alloimmunization is one of the major challenges to regular transfusions in β-thalassemic patients. In Morocco, rare studies have focused on this hemoglobinopathy.
We aimed to study the prevalence and risk factors of red cell alloimmunization in β-thalassemic patients.
Retrospective study during 9 years (2009-2018) was conducted on 160 β-thalassemic patients transfused regularly in pediatric department of children's hospital in Casablanca, Morocco. The main clinical, demographic and transfusional characteristics of alloimmunized and non-alloimmunized patients were compared. Red blood cells units transfused were leukodeplated and phenotypically matched for RH-KELL systems and for other systems after immunization. Screening and antibody identification were performed by gel-filtration method on BIO-RAD caseds using 3 and 11 red blood cells panels. To detect autoantibodies, autocontrol and direct antiglobulin tests were carried out using polyspecific coombs (IgG/C3d) gel cards.
The prevalence of alloimmunizations was 8.75% during the study period. Seventeen alloantibodies identified were directed mainly against antigens of KELL and RH systems: KEL 1 (35.29%), RH 3 (23.52%), RH1 (11.76%), Kpa (11.76%), RH2 (5.88%). Red blood cells autoantibodies had been detected in 6 of 14 (42.85%) of alloimmunized patients versus 12 of 146 (11.76%) of non-alloimmunized patients (P<0.01). Presence of autoantibodies, transfusional interval<3weeks and gender were associated with high rate of red cells alloimmunization.
This study proves the data of literature. The presence of red cell autoantibodies appears to be a major risk factors for alloimmunization in thalassemic children, and could advocate specific transfusion guidelines.
红细胞同种免疫是β地中海贫血患者定期输血面临的主要挑战之一。在摩洛哥，针对这种血红蛋白病的研究很少。
我们旨在研究β地中海贫血患者红细胞同种免疫的患病率及危险因素。
对摩洛哥卡萨布兰卡儿童医院儿科定期输血的160例β地中海贫血患者进行了为期9年（2009 - 2018年）的回顾性研究。比较了同种免疫患者和非同种免疫患者的主要临床、人口统计学和输血特征。输注的红细胞单位进行了白细胞滤除，并且在免疫后根据RH-KELL系统及其他系统进行了表型匹配。使用3个和11个红细胞面板，通过凝胶过滤法在BIO-RAD试剂盒上进行筛选和抗体鉴定。为检测自身抗体，使用多特异性抗人球蛋白（IgG/C3d）凝胶卡进行自身对照和直接抗球蛋白试验。
研究期间同种免疫的患病率为8.75%。鉴定出的17种同种抗体主要针对KELL和RH系统的抗原：KEL 1（35.29%）、RH 3（23.52%）、RH1（11.76%）、Kpa（11.76%）、RH2（5.88%）。在14例同种免疫患者中有6例（42.85%）检测到红细胞自身抗体，而非同种免疫的146例患者中有12例（11.76%）检测到（P<0.01）。自身抗体的存在、输血间隔<3周和性别与红细胞同种免疫的高发生率相关。
本研究证实了文献数据。红细胞自身抗体的存在似乎是地中海贫血儿童同种免疫的主要危险因素，可能需要制定特定的输血指南。
