Transfusion-Associated Graft-Versus-Host Disease Risk and Transfusion Requirements After Cladribine in Multiple Sclerosis: Time to Revise Irradiation Policy?

BACKGROUND

Irradiation of cellular blood components prevents transfusion-associated graft-versus-host disease (TA-GVHD). UK and Spanish guidance recommend lifelong irradiation for all patients treated with purine analogues, including cladribine, irrespective of indication or dose.

OBJECTIVE

To assess whether this approach is justified for people with multiple sclerosis (pwMS) receiving cladribine.

METHODS

Narrative synthesis of immunological data, hemovigilance evidence, and national European transfusion guidelines.

RESULTS

Cladribine used in pwMS induces transient lymphopenia with modest, reversible T-cell effects and preserved vaccine responsiveness. Since introduction of universal pre-storage leucocyte depletion, hemovigilance data show no reported cases of TA-GVHD in this setting. European guidance is heterogeneous, ranging from indefinite to time-limited or unspecified durations.

CONCLUSION

Current evidence does not clearly support the need for lifelong irradiation after cladribine treatment in pwMS. Time-limited or individualized approaches merit consideration.