Automation is gaining favor for pre-transfusion testing to improve efficiency. Since microtube column agglutination systems were introduced, they have been compared with tube methods for detection of alloantibodies. These reports indicate that gel column systems are similar to tube polyethylene glycol (PEG)-indirect antiglobulin (IAT) in detecting clinically significant antibodies [1]. Moreover, Weisbach et al. showed that the sensitivity of a number of microtube column system in the detection of clinically significant antibodies was similar, even superior, to that of tube low ionic strength solution (LISS)-IAT [2]. In contrast, gel techniques have been reported to be less sensitive than tube techniques in the detection of anti-Fy^b, anti-Jka, anti-S [3], and anti-E [4]. These differences might be affected by the kind of column used and, for tube methods, the enhancement medium.

We compared a gel column method (WADiana Compact, Grifols International, Spain) against manual PEG-IAT [5], for detection of red cell alloantibodies. We paralleled screening results prospectively between November and December 2012 on 270 samples and serial dilutions of 11 samples with known red cell alloantibodies were compared for antibody reactivity by AABB score.

The results of screening show a concordance rate of 97.8% (5 samples both positive, 259 samples both negative) and discordance in 6 samples: 1 sample showed anti-M cold reactive specificity by gel column that was negative by tube PEG-IAT; 5 samples included 2 anti-E and 1 each anti-Fy^b, -Jk^a, -Le^a by tube PEG-IAT that were negative by gel column. These 5 samples with weak reactivity in tubes were from 4 patients (two anti-E were obtained from same patient on different days).

Titration studies showed overall higher AABB scores by tube PEG-IAT compared with gel column. In particular, anti-Fy^b, -C were only detected in tube PEG-IAT, but anti-M with weak reactivity was only detected by gel column (Figure 1).

In summary, gel column methods compared to tube methods using PEG have limitations in detecting alloantibodies that are weakly reactivity by tubes, but clinically significant. Automated systems can prevent human errors and they streamline and standardize pre-transfusion testing, especially in multi-purpose laboratories. Still, we should note that some alloantibodies with weak reactivity by tube PEG-IAT may be missed by gel column methods, and entertain a potential increase of delated hemolytic transfusion reactions.

Keywords: Antibody screening, Automated column, Manual tube

1. Winters JL, Richa EM, Bryant SC, Tauscher CD, Bendix BJ, Stubbs JR. Polyethylene glycol antiglobulin tube versus gel microcolumn: influence on the incidence of delayed hemolytic transfusion reactions and delayed serologic transfusion reactions. Transfusion 2010 Jul;50(7):1444–52.   [CrossRef]   [Pubmed]    
2. Weisbach V, Ziener A, Zimmermann R, Glaser A, Zingsem J, Eckstein R. Comparison of the performance of four microtube column agglutination systems in the detection of red cell alloantibodies. Transfusion 1999 Oct;39(10):1045–50.   [CrossRef]   [Pubmed]    
3. Phillips PK, Whitton CM, Lavin F. The use of the antiglobulin 'gel-test' for antibody detection. Transfus Med 1992 Jun;2(2):111–3.   [CrossRef]   [Pubmed]    
4. Lillevang ST, Georgsen J, Kristensen T. An antibody screening test based on the antiglobulin gel technique, pooled test cells, and plasma. Vox Sang 1994;66(3):210–5.   [CrossRef]   [Pubmed]    
5. Okutsu M, Ohto H, Yasuda H, et al. Increased detection of clinically significant antibodies and decreased incidence of delayed haemolytic transfusion reaction with the indirect antiglobulin test potentiated by polyethylene glycol compared to albumin: a Japanese study. Blood Transfus 2011 Jul;9(3):311–9.   [CrossRef]   [Pubmed]