Humoral immunity and complement effector mechanisms after lung transplantation

Area of Science:

• Immunology
• Transplantation Medicine
• Pulmonary Medicine

Background:

• Lung transplantation (LTx) is a life-saving procedure for end-stage lung diseases.
• Bronchiolitis obliterans syndrome (BOS) significantly reduces LTx survival due to airway fibrosis.
• The exact pathophysiology of BOS remains incompletely understood.

Purpose of the Study:

• To review the role of HLA, non-HLA, and autoantibodies in BOS development.
• To elucidate the mechanisms of complement activation in BOS pathogenesis.
• To discuss the influence of regulatory mechanisms on lung graft survival.

Main Methods:

• Review of existing literature on antibodies and complement in LTx.
• Analysis of the association between allo- and autoantibodies and BOS progression.
• Examination of complement effector pathways and regulatory mechanisms.

Main Results:

• Both anti-HLA and non-HLA antibodies correlate with LTx outcomes.
• Autoimmunity, involving autoantigens like Type V collagen, contributes to BOS.
• Complement activation, triggered by antibody binding, plays a key role in BOS pathogenesis.

Conclusions:

• Antibodies (HLA, non-HLA, auto-) are critical in BOS development.
• Complement activation is a central mechanism in BOS.
• Understanding these pathways may lead to improved strategies for graft survival.