Bay, Jakob Thaning2; Sørensen, Søren S3; Hansen, Jesper M5; Madsen, Hans O3; Garred, Peter5
1 Section of Surgery and Internal Medicine, Department of Clinical Medicine, Faculty of Health and Medical Sciences, Københavns Universitet2 Institut for Klinisk Medicin3 unknown4 Department of Clinical Medicine, Department of Clinical Medicine, Faculty of Health and Medical Sciences, Københavns Universitet5 Department of Clinical Medicine, Department of Clinical Medicine, Faculty of Health and Medical Sciences, Københavns Universitet
Activation of the complement system is initiated by the alternative, the classical, or the lectin pathway. As the complement system is involved in the pathophysiology of graft rejection after kidney transplantation, we investigated the possible role of mannose-binding lectin in kidney transplantation and the influence of human leukocyte antigen (HLA) immunization on this process. In a prospective study of 544 kidney transplant patients over a follow-up period of 5 years, low serum levels of this lectin at the time of transplantation were found to be significantly associated with decreased 5-year death-censored graft survival (hazard ratio 1.68). Subanalysis showed that this association was confined to non-HLA-immunized patients (hazard ratio 1.93). The strongest association was seen in non-HLA-immunized patients receiving a kidney from a deceased donor (hazard ratio 2.93). No significant association with mannose-binding lectin levels and graft survival were found in HLA-immunized patients. Variant MBL2 genotypes causing low mannose-binding lectin serum concentrations showed the same association pattern. Our findings demonstrate a clear protective role of mannose-binding lectin and thus innate immunity in maintaining kidney graft survival, but these are probably overruled by HLA immunization.Kidney International advance online publication, 21 November 2012; doi:10.1038/ki.2012.373.