为提升IPTR患者血小板输注后CCI值建立分级规避HLA抗体对应抗原方法及HLAMatchmaker的应用研究

Establish a Graded Method to Avoid HLA Class I Antibodies Corresponding Antigen and Combining HLAMatchmaker Application in Improving the CCI Value after Platelet Transfusion for Patients with IPTR

目的:建立分级规避HLA抗体MFI阈值对应抗原方法,联合应用HLAMatchmaker表位计算法,选择供患者表位最小错配评分值,评估两种方法为免疫性血小板输注无效(Immune platelet transfusion refractoriness,IPTR)患者选择HLA相容性血小板供者,在提升血小板输注后校正增加值(CCI)的应用价值。方法:采用SPRCA法完成51例IPTR患者的7807次血小板交叉配型实验,判断其免疫反应阴/阳性结果。采用Luminex单抗原流式微珠法检测患者的HLA-I类抗体,获得不同特异性抗体对应HLA-I类抗原MFI值,并将其分组及分级,强阳性组(MFI>4000,1级)、中阳性组(1000中阳性组>弱阳性组)。强阳性和中阳性组与阴性对照组之间的SPRCA实验免疫反应阳性结果检出数存在统计学差异(P<0.001),弱阳性位组和阴性对照组之间的SPRCA实验免疫反应阳性结果检出数无统计学差异(P>0.05)。设置强阳性组为相应特异性HLA位点对应抗原1级规避阈值,中阳性组为2级规避阈值,弱阳性组为3级规避阈值,在供者血小板紧缺情况下,可以不需要规避弱阳性组。规避1和2级HLA-I类抗体对应供者抗原及选择HLAMatchmaker表位错配评分数≤7血小板供者策略,24 h内CCI值均>4.5×109/L,均可获得临床血小板输注有效。结论:在为IPTR患者选择HLA-I类相容性供者时,分级规避HLA-I类抗体对应供者抗原,综合选择供受者HLAMatchmaker表位错配评分数≤7,经血小板交叉配型实验确认为阴性结果的供者选择策略,对提升IPTR患者血小板计数具有一定实际应用价值。

Objective:To establish a graded method to avoid mean fluorescence intensity(MFI)threshold of HLA Class I antibodies corresponding antigen,and the HLAMatchmaker program has been used to select the minimum mismatch value of donor-patient epitopes.Evaluate the application value of combining both methods in selecting HLA compatible platelets(PTL)for patients with immune platelet transfusion failure(IPTR)in improving platelet the corrected count increment(CCI).Methods:A total 7807 PLT cross-matching compatible were performed by the solidphase red cell adherence(SPRCA)method for 51 IPTR patients.The Luminex single antigen flow cytometry w as used to detect HLA Class I antibodies in patients,and detected the M FI value for different specificity antigens of HLA Class I antibodies,w as graded into strong positive group(M FI>4000,level 1),medium positive group(1000<M FI≤4000,2),w eak positive group(500<M FI≤1000,3),and one negative control group(M FI≤500).The results of7807 SPRCA their negative/positive reaction w ells w ere enrolled and statistically analyzed in different grades and the four groups,the statistical differences betw een the four groups w ere compared.M ultiple applications for the select HLA Class I compatible donor events w ere made for patients in tw o cases,and HLAM atchmaker program w as used to calculate the number of HLA Class I epitopes mismatches betw een the donors and patients.The donor w ith the minimum number of epitopes mismatches w as selected,w hile avoiding the corresponding antigens of HLA Class I antibodies in levels 1 and 2,the provision of HLA compatible platelets for IPTR.After the transfusions,the CCI value of the platelet transfusion efficacy evaluation index w as calculated,and the clinical evaluation of the transfusion effect w as obtained through statistical analysis.Results:There w ere statistically significant differences in the positive results of SPRCA immunoassay among the strong positive group,medium positive group,and w eak positive group of 51 IPTR patients w ith different specific of HLA-I class antibodies and corresponding antigens(all P<0.001).The positive results show ed a range from high to low,w ith strong positive group>medium positive group>w eak positive group.There w ere a statistical difference among betw een the strongly positive or moderately positive groups and the negative control group(P<0.001).There w as no statistical difference betw een the w eakly positive group and the negative control group(P>0.05).The strong positive group w as set as the corresponding specific HLA Class I site corresponding antigen grade 1avoidance threshold,the medium positive group as the grade 2 avoidance thresholds,and the w eak positive group as the grade 3 avoidance threshold.In the case of donor platelet shortage,it is not necessary to avoid the w eak positive group.Avoiding the strategy of donor antigens and HLAM atchmaker program scores≤7 corresponding to HLA Class I antibodies of levels 1 and 2,w ith CCI values>4.5×109/L w ithin 24 hours,can obtain effective clinical platelet transfusion conclusions.Conclusion:When selecting HLA Class I compatible donors for IPTR patients,the grading avoids HLA Class I antibodies corresponding to donor antigens,and the donor selection strategy w ith the minimum scores of HLAM atchmaker program is comprehensively selected.The negative result confirmed by platelet crossmatching experiments has certain practical application value for improving platelet count in IPTR patients.