Transfusion-related immune modulation (TRIM)

This is a delayed (>24 hours), immunological transfusion reaction.

When to suspect this adverse reaction?

TRIM is a transient immunosuppression in recipients which may occur following transfusion of allogeneic blood.

No specific signs or symptoms have been attributed to TRIM.(2)

The incidence rate of TRIM is not known.(1)

Usual causes?

No specific mechanisms have been definitely proven as the pathway for post-transfusion immunosuppression.(2) It is partially due to transfused white cells releasing cytokines, which leads to immune modulation.

There have been a number of reported TRIM-associated effects on the transfusion recipient ranging from improved clinical outcome in renal allograft transplantation to an increased rate of tumour recurrence in cancer surgery patients and an increased rate of post-operative bacterial infection.(2)


No specific investigation process has been defined.

What to do?

Removal of donor white cells by prestorage filtration of cellular blood components may help to lessen TRIM. Leucodepletion may have potential benefits for reducing TRIM effects.

  1. Roback JD (ed). Non-infectious complications of blood transfusion. Chapter 27, AABB Technical Manual, 17th edition. AABB, Bethesda, 2011.
  2. Harmening DM (ed). Chapter 18, Adverse Effects of Blood Transfusion. Modern Blood Banking and Transfusion Practices, 5th edition. FA Davis Company, Philadelphia, 2005.