Introduction: Autoimmune Hemolytic anemia (AIHA) after solid organ transplantation is a relatively rare but severe complication. In contrast, after intestinal transplantation the incidence is up to 12.2% and generally occurs between 8-10 months after transplantation. Published therapeutic regimes include high-dose corticosteroids, intravenous immunoglobulin, plasmapheresis, rituximab and a switch of tacrolimus-immunosuppression towards other options, but the anemia can be refractory to this treatment. The overall mortality rate of AIHA is about 8%.

Bortezomib is a selective and reversible proteasome 26S inhibitor that directly inhibits antibody production through plasma cell depletion, it is registered as a treatment of multiple myeloma and chronic cold agglutin disease after allogenic hematopoietic stamcell transplantation (HSCT).

Methods: In this case-report we describe a 5-year old boy with microvillous inclusion disease who developed severe haemolytic anemia (Coombs negative) circa one year after multivisceral transplantation, which was unresponsive to conventional therapy with high dose steroids, IVIG and a switch from tacrolimus to cyclosporine. Plasmapheresis was not feasible due to circulatory instability. Because we ran out of therapeutic options a trial with bortezomib (Velcade®) at a dose of 1.0-1.3 mg/m2was given every 3 days, four times in total (with a second course 10 days later).

Results: We observed a rapid and sustained raise in haemoglobin within the first week after administration of bortezomib. During the treatment he developed a transient increased in stoma production, leucopenia and a raise in transaminase. Three years later he is doing well and never relapsed.

Conclusion: This is the first report to describe the use of bortezomib in the treatment of refractory autoimmune hemolytic anemia after multivesceral transplantation. In our case the therapy was relatively well tolerated and gave a fast and sustained favourable response with a long-term follow-up of over 3 years. The occurrence of AIHA and its treatment after multivisceral transplantation should be the subject of future registry studies to collect additional experience and explore the optimal therapeutic approach. Bortezomib should be regarded as an important therapeutic alternative for AIHA after solid organ transplantation.