Direct Antiglobulin Test/Direct Coombs Test

Assay

Key Words

DAT, Direct Coombs Test, Direct Antiglobulin Test

Specimen Collection

7.5ml EDTA or 3.4ml EDTA for adults (Red lid). 1.3ml EDTA for paediatric (Red lid), do not overfill.

Turnaround time

1 working day. Emergency requests 1 hour.

Test indications

Investigation of autoimmune haemolysis and transfusion reactions.

Test outcome:		Consider:
IgG	C3b3d	Consider:
-	-	No red cell sensitisation detected
+	- (rarely + but possible)	Warm Auto-Immune Haemolytic Anaemia (AIHA) Drug-dependent haemolytic anaemia, Haemolytic disease of the foetus & newborn
+	- (Can be +)	Allo-Immune Haemolytic anaemia e.g. Delayed Haemolytic Transfusion Reaction (DHTR) Drug-independent haemolytic anaemia,
- (Can be +)	+	Allo-Immune Haemolytic Anaemia e.g. Acute Haemolytic Transfusion Reaction (HTR)
-	+	Cold Auto-Immune Haemolytic Anaemia (AIHA) e.g. Cold Haemagglutinin Disease (CHAD) Paroxysmal Cold Haemoglobinuria (PCH)

Interferences

Haemolysed or lipaemic samples may not be able to complete testing, whereupon new samples will be required.

Reference Range

N/A

Minimum retesting interval

N/A