What is the purpose of using a 'two-stage' crossmatch technique in blood transfusion?

A To detect ABO incompatibility
B To detect non-ABO antibodies ✓
C To reduce the risk of transfusion-related acute lung injury (TRALI)
D To increase the speed of crossmatching

Explanation

The two-stage crossmatch technique is used to detect non-ABO antibodies, which can cause a transfusion reaction. The first stage involves an indirect antiglobulin test (IAT), and the second stage involves a direct antiglobulin test (DAT).

Source

AABB Technical Manual
Hematology Hematology: Blood Grouping and Crossmatching Hematology: Blood Grouping and Crossmatching Hard MEDICAL Confidence: medium