sCD59 as a novel biomarker for acute rejection in kidney transplantation

L.A. Michielsen, A.D. van Zuilen, T. Kardol-Hoefnagel, M.C. Verhaar, H.G. Otten

Friday 16 march 2018

10:00 - 10:05h at Willem Burger Foyer

Categories: Clinical, Session (poster)

Parallel session: Poster session 7: Clinical

The membrane bound complement regulatory protein CD59 protects cells against formation of the membrane attack complex. Upon cell activation and damage, membrane bound proteins including CD59 can be shed from the cell surface. The soluble form of CD59 (sCD59) can be detected amongst others in serum, plasma and urine, though it is unknown whether these levels are related to each other. We hypothesized that sCD59 levels are increased during kidney injury and as such may be used as a novel biomarker for acute rejection in kidney transplant patients.

We have included 10 kidney transplant patients with acute rejection during the first year and 10 matched patients without. Patients were matched on donor type and recipient age and sex. sCD59 concentrations were measured by ELISA in urine and serum samples that were collected prior to transplantation, posttransplantation at month 1, 3, 6 and 12 and if applicable at time of rejection. Urinary sCD59 concentrations were normalized for urinary creatinine levels.

Serum sCD59 concentrations at month 1 posttransplantation were markedly lower compared to pretransplantation in all patients (average -56%, p<0.0001). In urine samples, a smaller average drop was observed (-19%, p=0.03) and not in all patients. The overall correlation between sCD59 levels in urine and serum was poor (R²=0.20, p<0.0001). Patients with a rejection episode, showed increased sCD59 levels in serum and urine (median 19.1ng/ml and 113.9ngml) at time of rejection compared to the average posttransplant concentration in patients without rejection (median 12.4ng/ml and 83.6ng/ml; p

 In conclusion, this data shows that serum and urinary sCD59 levels decline posttransplantation and are increased in patients with acute rejection. Therefore, sCD59 levels might be alone or in combination with other markers a novel biomarker for acute rejection in kidney transplantation.