Department of Clinical Pathology, University Health Network, Toronto, Ontario, Canada.
Department of Laboratory Medicine & Pathobiology, University of Toronto, Toronto, Ontario, Canada.
Transfusion. 2021 Jun;61(6):1749-1756. doi: 10.1111/trf.16388. Epub 2021 Apr 2.
Antenatal titration testing is traditionally performed using a manual tube test. Tube testing has limitations; it is a manual, time-consuming method with wide interobserver variability. Gel-based testing is an attractive alternative because it is more precise and can be automated. This study's objective was to summarize the published literature that assessed the relationship between titrations performed by tube and gel for anti-D alloimmunized pregnancies.
A comprehensive literature search was performed. Articles were selected if research was original and compared at least five pairs of anti-D titration tests performed by gel and tube. Differences in the number of dilutions between gel and tube methods were compared overall by study and cell type using linear models.
A total of 512 articles were identified; eight were included, and titer data from 384 tube and gel pairs were abstracted. The median anti-D titer in tube was 8 (range 0-2048) and by gel was 64 (range 0-4096). Anti-D gel titration results were 2.1 (95% CI; 1-3.3) additional dilutions greater than in tube. Most studies utilized double-dose reagent cells for testing. At a tube titer of 16, the sensitivity and specificity of gel titrations is maximal (91% and 94% respectively) at a gel titer of 64.
Overall, titrations performed by gel were two dilutions higher than the corresponding tube titer. For titrations, double-dose reagent cells should be considered to standardize practice. A rigorous prospective study is needed to compare tube titrations with gel titrations using a standardized process.
传统上，产前滴定测试使用手动管测试进行。管测试有其局限性；它是一种手动的、耗时的方法，观察者之间的差异很大。基于凝胶的测试是一种有吸引力的替代方法，因为它更精确并且可以自动化。本研究的目的是总结评估抗-D 同种免疫妊娠中管和凝胶进行滴定的关系的已发表文献。
进行了全面的文献检索。如果研究是原创的并且至少比较了 5 对通过凝胶和管进行的抗-D 滴定测试，则选择文章。使用线性模型，总体上按研究和细胞类型比较凝胶和管方法之间稀释度差异。
总共确定了 512 篇文章；纳入了 8 篇，并且从 384 对管和凝胶中提取了滴定数据。管中的平均抗-D 滴度为 8（范围 0-2048），凝胶中的滴度为 64（范围 0-4096）。抗-D 凝胶滴定结果比管中的结果高 2.1（95%置信区间；1-3.3）个稀释度。大多数研究使用双剂量试剂细胞进行测试。在管滴度为 16 的情况下，凝胶滴度为 64 时，凝胶滴定的灵敏度和特异性最大（分别为 91%和 94%）。
总体而言，凝胶进行的滴定比相应的管滴度高两个稀释度。对于滴定，应考虑使用双剂量试剂细胞来标准化实践。需要进行严格的前瞻性研究，以使用标准化流程比较管滴定和凝胶滴定。
