Comparative evaluation of DTT treated ABO isoagglutinin titres performed by two methods with solid phase red cell...

Measurement of actual concentration of IgG requires methods like treatment of serum with dithiothreitol (DTT). This study was aimed at comparing of DTT treated ABO titres performed by conventional test tube technique (CTT) and column agglutination technique (CAT) with HA/SPRCA.

This was a prospective, observational study conducted from October 2019 to March 2020. All consecutive A, B and O group donors who gave consent for participation were included. All samples were tested by CTT and CAT before and after DTT treatment (pCTT, pCAT) and with HA/SPRCA.

A total of 300 donors were included; 100 each from A, B and O blood group donors. Group O titres were higher than group A/B titres. Group O titres were highest when performed by pCAT, followed by pCTT and lowest by HA/SPRCA. Group A/B titres were highest when performed by HA/SPRCA, followed by pCAT and pCTT for anti-A and highest when performed by pCAT, followed by HA/SPRCA and lowest by pCTT for anti-B.

Results obtained by pCAT were closer to results obtained by pCTT, whereas those obtained by HA/SPRCA were variable. SPRCA offers the advantage of automation, no inter-observer variation and less time consumption because IgM interference is not observed with SPRCA, thus providing an alternative to pCTT. However, these methods cannot be used interchangeably and to discern the most suitable method, a clinical impact of these results needs to be studied.