Branch D R, Petz L D
Am J Clin Pathol. 1982 Aug;78(2):161-7. doi: 10.1093/ajcp/78.2.161.
A reagent (ZZAP) containing a mixture of 0.1 M dithiothreitol (DTT) plus 0.1% cysteine-activated papain was found to dissociate IgG immunoglobulin from red blood cells (RBC) of patients having a positive direct antiglobulin test (DAT) although this could not be achieved with either chemical alone. In all 67 patients tested, ZZAP treatment of IgG sensitized RBC reduced the strength of the DAT, and in all 52 instances tested, this allowed for accurate Rh phenotyping using slide/rapid tube typing reagents. This included five examples in which spontaneous agglutination that occurred in saline or 6% albumin was eliminated by ZZAP. Thus, all red blood cell typing for Rh-Hr antigens was accomplished using slide/rapid tube reagents making unnecessary the use of saline reactive or chemically modified antisera. Kidd antigen typing is also possible after ZZAP treatment of IgG sensitized RBC. In regard to warm autoabsorption tests, ZZAP treatment of 14 RC samples having a positive DAT proved preferable to heat elution technics since equal or greater amounts of IgG were removed by ZZAP and little or no hemolysis resulted. ZZAP has no effect on ABH, Rh or Kidd antigens but denatures Duffy, MNSs and all Kell antigens tested (K:1-K:7, K:11-K:14, K:18, K:19). This should prove valuable in certain investigations of multiple alloantibodies and, moreover, may allow for better characterization of Kell antigens.
一种含有0.1M二硫苏糖醇（DTT）加0.1%半胱氨酸激活木瓜蛋白酶混合物的试剂（ZZAP），被发现可使直接抗球蛋白试验（DAT）呈阳性患者的红细胞（RBC）上的IgG免疫球蛋白解离，尽管单独使用任何一种化学物质都无法实现这一点。在所有67例受试患者中，用ZZAP处理IgG致敏的RBC可降低DAT的强度，并且在所有52例受试情况下，这使得使用玻片/快速试管分型试剂进行准确的Rh分型成为可能。这包括5个例子，其中ZZAP消除了在盐水或6%白蛋白中发生的自发凝集。因此，所有Rh-Hr抗原的红细胞分型均使用玻片/快速试管试剂完成，无需使用盐水反应性或化学修饰的抗血清。对IgG致敏的RBC进行ZZAP处理后，也可以进行基德抗原分型。关于温自身吸收试验，对14份DAT呈阳性的红细胞样本进行ZZAP处理被证明优于热洗脱技术，因为ZZAP去除的IgG量相等或更多，且几乎没有溶血或不产生溶血。ZZAP对ABH、Rh或基德抗原无影响，但会使达菲、MNSs以及所有检测的凯尔抗原（K:1-K:7、K:11-K:14、K:18、K:19）变性。这在某些多种同种抗体的研究中应具有重要价值，此外，可能有助于更好地鉴定凯尔抗原。
