Persistent complement-dependent anti-AnWj in a lymphoproliferative disorder: a case study and review.

Area of Science:

• Immunology
• Hematology
• Transfusion Medicine

Background:

• AnWj is a common red blood cell antigen found in over 99% of the population.
• Hematopoietic stem cell transplantation (HSCT) is a treatment for hematologic malignancies.
• Graft failure after HSCT can necessitate ongoing blood component support.

Observation:

• A patient undergoing autologous HSCT for mantle cell lymphoma experienced graft failure.
• Following transfusion support, the patient developed severe reactions including fever and intravascular hemolysis.
• Testing revealed a complement-dependent anti-AnWj antibody and an AnWj-negative phenotype.

Findings:

• The patient developed a clinically significant anti-AnWj antibody response.
• The anti-AnWj antibody persisted despite immunosuppressive therapy and allogeneic HSCT.
• The AnWj-negative phenotype of the graft RBCs was confirmed.

Implications:

• This case highlights the potential for alloimmunization against high-incidence antigens like AnWj in patients requiring chronic transfusion support.
• Understanding the pathogenesis of AnWj antigen downregulation post-transplant is crucial for managing transfusion reactions.
• Further research is needed to elucidate the mechanisms behind AnWj antigen expression changes after HSCT.