Plasma cell targeting to prevent antibody-mediated rejection

Area of Science:

• Immunology
• Transplantation
• Pharmacology

Background:

• Plasma cells (PCs) are key producers of pathogenic antibodies, yet are therapeutically challenging.
• Long-lived bone marrow resident PCs (LLPCs) exhibit resistance to proteasome inhibitors (PIs).
• Durability of antibody reduction in clinical settings requires enhancement.

Purpose of the Study:

• To review recent advances in plasma cell biology.
• To highlight clinical trial progress targeting plasma cells in transplant populations.
• To discuss the efficacy and limitations of proteasome inhibitors in plasma cell depletion.

Main Methods:

• Review of recent clinical trials involving proteasome inhibitors (e.g., carfilzomib).
• Analysis of mechanistic studies on plasma cells from treated patients.
• Integration of findings from murine studies on plasma cell heterogeneity and biology.

Main Results:

• Second-generation PIs, like carfilzomib, improve elimination of bone marrow PCs and reduce anti-HLA antibodies.
• Therapeutic resistance is observed in long-lived bone marrow resident PCs.
• Antibody rebound occurs weeks to months after PI therapy, indicating a need for improved strategies.
• Bone marrow PCs are heterogeneous with distinct biological signatures.

Conclusions:

• Recent clinical trials and murine studies offer new insights into plasma cell biology.
• Targeting plasma cells with second-generation PIs shows clinical benefit but requires optimization for durable antibody reduction.
• Understanding plasma cell heterogeneity is key to developing more effective therapies for antibody-mediated diseases in transplant recipients.