C3d and C4d deposition early after lung transplantation.
BACKGROUND
Complement staining as a predictor of antibody-mediated rejection (AMR) after lung transplantation continues to be debated.


METHODS
In a cohort of 33 lung transplant recipients (LTRs) we assessed early post-transplant (<or=3 months) graft deposition of the complement factors C3d and C4d and correlated staining with clinical outcome. A retrospective analysis of allograft C3d and C4d deposition was performed by an experienced histopathologist blinded to clinical outcomes. Biopsies were graded 0 to 3 based on extent of septal capillary complement staining.


RESULTS
Significant C3d and C4d staining (i.e., Grade >or=2 on more than one occasion) was observed in 20 and 11 LTRs, respectively. Complement staining was increased in LTRs with severe primary graft dysfunction or airway infection, but was not associated with acute cellular or chronic rejection, or with morphologic features of AMR. In a sub-group analysis we identified 9 LTRs who developed early bronchiolitis obliterans syndrome (BOS) in the absence of acute cellular rejection or cytomegalovirus reactivation, but they had significant lung allograft C3d/C4d deposition along with corroborative light-microscopic features suggestive of AMR.


CONCLUSIONS
Complement activation, as judged by lung allograft deposition of C3d/C4d, is common early post-lung transplant and may be triggered by primary graft dysfunction and/or airway infection, and may play a role in the development of early BOS.
Westall
Glen P
GP
Department of Allergy, Immunology and Respiratory Medicine, Alfred Hospital and Monash University Medical School, Melbourne, Victoria, Australia. g.westall@alfred.org.au
Snell
Greg I
GI
McLean
Catriona
C
Kotsimbos
Tom
T
Williams
Trevor
T
Magro
Cynthia
C
D000293:Adolescent; D000328:Adult; D001706:Biopsy; D001989:Bronchiolitis Obliterans / Q000473:pathology; D015933:Complement C3d / Q000032:analysis*; D015935:Complement C4b / Q000032:analysis*; D005260:Female; D006084:Graft Rejection / Q000473:pathology*; D006801:Humans; D008168:Lung / Q000473:pathology*; D016040:Lung Transplantation / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000032:analysis*; D012189:Retrospective Studies
D010446:Peptide Fragments; D015933:Complement C3d; D015935:Complement C4b; C032261:complement C4d