Role of de novo donor‐specific anti‐HLA antibodies in kidney graft failure: A case‐control study

The role of de novo donor‐specific anti‐human leukocyte antigen (anti‐HLA) antibodies (dnDSA) within the pathways leading to graft failure remains not fully understood. We investigated 56 patients who were transplanted between 2002 and 2014 with kidney graft failure (cases), for a possible association of development of dnDSA with graft failure. The 56 patients with failed transplants were matched with 56 patients with a functioning graft at present for the variables deceased or living donor, transplant number, transplant year, recipient age and gender, donor age and gender, dialysis vintage time, transplant induction therapy. All patients had at least one serum collected 1 year before failure (in cases) or end of follow‐up (in controls). Cases and controls were very well‐matched in several baseline characteristics. Post‐transplant anti‐HLA antibodies were found in 84% of cases and only 36% of controls (P < .001), with 54% of cases and 16% of controls (P < .001) having dnDSA at time of detection. Chronic active antibody‐mediated rejection was significantly more common (P < .001) in patients with dnDSA (61% vs 12%), in 53 (47%) patients that had at least one graft biopsy performed during follow‐up. dnDSA was a significant risk factor (odds ratio [OR] = 6.06; P = .003) for graft failure in a multivariable conditional logistic regression model. dnDSA as a time‐dependent variable, was also an independent predictor [hazard ratio (HR) = 2.46; P = .002] of graft failure in a multivariable Cox regression analysis. In both statistical approaches, only dnDSA‐II (OR = 11.90; P = .006) (HR = 2.30; P = .014) was significantly associated with graft failure. Post‐transplant dnDSA was clearly associated with graft loss, particularly if against HLA class II antigens. dnDSA detection should be a tool for post‐transplant monitoring of kidney graft recipients, allowing for the identification of those with a higher risk of graft failure.