Judd W J, Steiner E A, Abruzzo L V, Davenport R D, Oberman H A, Pehta J C, Nance S J
Department of Pathology, University of Michigan Medical Center, Ann Arbor.
Transfusion. 1992 Jul-Aug;32(6):572-5. doi: 10.1046/j.1537-2995.1992.32692367204.x.
A unique case of acute hemolysis following transfusion of red cells (RBCs) that were found compatible by immediate-spin (IS) crossmatch technique is reported. Screening tests for unexpected antibodies, using low-ionic-strength saline (LISS), 10 minutes' incubation at 37 degrees C, and anti-IgG, were nonreactive; however, 1 transfused unit was found crossmatch incompatible by indirect antiglobulin technique (IAT). An anti-i (titer 512 at 4 degrees C) that was not an autoantibody was identified in the patient's serum. Unlike the incriminated donor RBCs, most I+ RBCs did not react by LISS-IAT. Variable reactivity was seen with ficin-treated I+ RBCs, and there was marked hemolysis of iadult and icord RBCs. In marked contrast, dominant Lu(a-b-) RBCs, with reduced expression of i, did not react by any test method; nor did autologous I+, Lu(b+) RBCs. The in vivo clinical significance of this anti-i was confirmed by monocyte monolayer assay and RBC survival studies. The patient's i antigen may have been altered, by either chemotherapy or disease, and lacked part of the i antigen-mosaic. Her antibody was directed at epitopes of i that were absent from her RBCs. Those i epitopes missing from her RBCs are also absent on dominant Lu(a-b-) RBCs. This anti-i represents a unique cause of an acute hemolytic transfusion reaction. It also represents a case of acute immune-mediated hemolysis following transfusion of IS crossmatch-compatible blood when screening tests for unexpected antibodies are nonreactive. Because of the rarity of such cases (less than 1/200,000 RBC units transfused), modifications to pretransfusion testing protocols are not proposed.
本文报告了一例独特的病例，患者输注经立即离心（IS）交叉配血技术检测为相容的红细胞（RBC）后发生急性溶血。采用低离子强度盐水（LISS）、37℃孵育10分钟及抗IgG进行意外抗体筛查试验，结果均为阴性；然而，1个输注单位的血液经间接抗球蛋白技术（IAT）检测发现交叉配血不相容。在患者血清中鉴定出一种非自身抗体的抗-i（4℃时滴度为512）。与受质疑的供者RBC不同，大多数I⁺ RBC在LISS-IAT试验中无反应。经胰蛋白酶处理的I⁺ RBC呈现出可变反应性，并且成人和脐血RBC出现明显溶血。与之形成鲜明对比的是，i表达减少的主要Lu（a-b-）RBC在任何检测方法中均无反应；自身I⁺、Lu（b⁺）RBC也无反应。通过单核细胞单层试验和RBC存活研究证实了这种抗-i在体内的临床意义。患者的i抗原可能因化疗或疾病而发生改变，并且缺乏部分i抗原镶嵌体。她的抗体针对的是其RBC中不存在的i表位。她的RBC中缺失的那些i表位在主要的Lu（a-b-）RBC中也不存在。这种抗-i代表了急性溶血性输血反应的一种独特病因。它也代表了在意外抗体筛查试验为阴性时，输注IS交叉配血相容血液后发生急性免疫介导溶血的病例。由于此类病例罕见（每输注200,000个RBC单位中少于1例），因此未建议对输血前检测方案进行修改。
