Irving C, Crennan M, Vanniasinkam T
Haematology Department, Melbourne Pathology, Collingwood, Victoria, Australia.
School of Biomedical Sciences, Charles Sturt University, Wagga Wagga, Australia.
Transfus Med. 2017 Oct;27 Suppl 5:362-368. doi: 10.1111/tme.12420. Epub 2017 May 15.
Enzyme indirect antiglobulin test (EIAT) and polyethylene glycol IAT (PIAT) were evaluated for their potential use as tests to distinguish between prophylactic and alloimmune anti-D in plasma by comparing with a tube variation of the standard low ionic strength solution-IAT (LISS-IAT).
Laboratories performing the screening of RhD-negative pregnant women are required to provide clinicians with guidance as to the source of detected RhD antibodies. Currently, this is derived from RhIg immunoprophylaxis history, agglutination scores and titration results, where performed. A serological test that can differentiate between prophylactic and alloimmune anti-D would be useful in the diagnosis of RhD alloimmunisation in pregnant women.
Plasma samples (n = 273) [fresh (collected from April 2014 to February 2015) and frozen (up to 2 years)] from antenatal females, preoperative males and females over child-bearing age were used in this study. Samples were identified as containing anti-D by routine column agglutination (CAT) and were tested by tube LISS-IAT, EIAT and PIAT, and a score difference was calculated.
A total of 32% of alloimmune anti-D samples demonstrated an increase in agglutination score (+2 or +3) when tested by EIAT. A significant increase in agglutination score for alloimmune samples using EIAT compared with LISS-IAT was observed. EIAT had a sensitivity (Sn) of 59%, positive predictive value (PPV) of 100% and specificity (Sp) of 100% for alloimmune anti-D.
EIAT is capable of confirming but not excluding the presence of alloimmune anti-D in samples where anti-D is detected in routine antibody screening.
通过与标准低离子强度溶液抗球蛋白试验（LISS-IAT）的试管法变体进行比较，评估酶间接抗球蛋白试验（EIAT）和聚乙二醇抗球蛋白试验（PIAT）作为区分血浆中预防性抗-D和同种免疫性抗-D检测方法的潜在用途。
进行RhD阴性孕妇筛查的实验室需要为临床医生提供有关检测到的RhD抗体来源的指导。目前，这是根据RhIg免疫预防史、凝集评分和滴定结果（如已进行）得出的。一种能够区分预防性抗-D和同种免疫性抗-D的血清学检测方法将有助于诊断孕妇的RhD同种免疫。
本研究使用了来自产前女性、术前男性和育龄期以上女性的血浆样本（n = 273）[新鲜样本（2014年4月至2015年2月采集）和冷冻样本（保存长达2年）]。通过常规柱凝集法（CAT）鉴定样本中含有抗-D，并通过试管LISS-IAT、EIAT和PIAT进行检测，并计算评分差异。
共有32%的同种免疫性抗-D样本在通过EIAT检测时凝集评分增加（+2或+3）。观察到与LISS-IAT相比，使用EIAT检测的同种免疫样本的凝集评分显著增加。EIAT对同种免疫性抗-D的敏感性（Sn）为59%，阳性预测值（PPV）为100%，特异性（Sp）为100%。
EIAT能够确认但不能排除在常规抗体筛查中检测到抗-D的样本中存在同种免疫性抗-D。
