采用酶联免疫吸附法(ELISA)检测重型p地中海贫血患儿的群体反应性抗体(panelreactive antibodies, PRA)，探讨反复输血的地中海贫血患儿体液致敏水平及其临床意义。

随机选择在中山大学附属第二医院儿科临床确诊为重型β地中海贫血的患儿，共计15例，男性患儿9例，女性6例；年龄为(6. 15±4. 01)岁。抽取外周血3 ml，离心分离血清，依据ELISA原理，采用美国One Lambda公司提供的莱姆德混合抗原板(LATM)和莱姆德抗原板(LAT)检测本组患儿的PRA水平及其特异性。

本组15例血液标本中，检出PRA呈阳性标本6例(PRA阳性组)，阳性检出率为40%，PRA强度为14%〜75%，中位PRA强度为47. 5%。PRA阳性组的输血总次数高于检测PRA呈阴性的9例标本(PRA阴性组)，两组比较，差异有极显著意义(P<0. 01)。PRA阳性组患儿的年龄、接受输血总时间高于PRA阴性组，两组比较，差异有显著性意义(P<0. 05)。此两组的输血开始时间比较，差异无显著意义(P>0. 05)。本研究的斯皮尔曼(Spearman)等级相关分析结果显示，PRA定性、PRA强度与输血总次数、患儿年龄、接受输血总时间呈正相关(P<0. 05);与输血开始时间无相关关系(P>0. 05)。

反复输血的重型β地中海贫血患儿PRA阳性率及强度较高；输血总次数越多、年龄越大、接受输血总时间越长的患儿，出现PRA呈阳性的几率越高，出现PRA强度高的几率越高；PRA可能是导致β地中海贫血患儿造血干细胞移植(HSCT)植入率低的原因之一。

To detect the panel reactive antibodies (PRA) in children with β-thalassemia major by enzyme-linked immunosorbent assay (ELISA) for investigating the level of sensitization and clinical significance of transfusion dependant.

Fifteen patients with β-thalassemia major who were diagnosed in our hospital selected by randomized study,nine of them were male and the other were female, the mean age was 6. 15 ± 4. 01 years. 3 ml of peripheral blood was obtained from all the subjects, and serum were collected after centrifugation. Using Lambda antigen tray mixed (LATM) and Lambda antigen tray (LAT), the level and specificity of serum PRA were detected by ELISA.

Among the fifteen samples of serum, six of them were PRA positive, the positive rate was 40% ; while the intensity of positive PRA was ranged from 14% to 75%, the median was 47. 5%. The frequencies of blood transfusion were much more in PRA positive group than in that of negative group, and the differences were statistically significant (P<0. 01). Moreover, the age of children and total time of blood transfusion were older and longer in PRA positive group than in that of negative group, respectively, and there were significant differences between these two groups (P<0. 05). However, no significant difference was found in the beginning time of transfusion between these two groups(P>0. 05). By Spearman analysis, there were positive correlations between the intensity of PRA and the following: frequency of blood transfusion, age of children, and total time of blood transfusion,(P<0. 05), except the beginning time of transfusion(P>0. 05).

The rate and intensity of positive PRA were quite high in children withβ-thalassemia major, and the effect may be more pronounced with increasing frequency of blood transfusion, age of child, and total time of blood transfusion. Serum PRA may be regarded as one of the reasons for the low engraftment in hematopoietic stem cells transplantation (HSCT) forβ-thalassemia.