Procalcitonin in the early phase after renal transplantation--will it add to diagnostic accuracy?

The determination of serum procalcitonin (PCT) was tested for its utility in detecting invasive bacterial infection and acute rejection during the first 6 wk after kidney transplantation. Fifty-seven kidney graft recipients were prospectively included in the study. In 13/57 patients, 16 episodes of acute biopsy-proven rejection occurred and were treated with high-dose steroids (n = 14) or with OKT3 (n = 2). Seventeen out of 57 patients experienced 19 invasive bacterial infections; 2/57 had partial graft necrosis due to malperfusion. Twenty-five out of 57 graft recipients experienced an uncomplicated postoperative course. A total of 116 samples were analyzed and the following data obtained: PCT, C-reactive protein (CRP), white blood cell (WBC) count, corresponding body temperature and serum creatinine. Procalcitonin values for patients with rejection did not differ significantly from those of the healthy transplant recipients (p = 0.47). In contrast, PCT was clearly elevated with invasive bacterial infection or partial graft necrosis (p < 0.01). OKT3 treatment of rejection led to a more than 10-fold increase in PCT. C-reactive protein, unlike PCT, was elevated to a variable extent in patients with graft rejection, though CRP values were significantly more elevated in patients with infection than in those with rejection (p < 0.01). The specifity for detection of invasive bacterial infection was 0.7 for PCT and 0.43 for CRP, whereas sensitivity was 0.87 for PCT and 1.0 for CRP. There was no correlation between PCT and serum creatinine (r = 0.06). Haemodialysis did not lower PCT serum concentrations. Procalcitonin values rose postoperatively to peak levels on the first and second days and mostly declined to normals within 1 wk. In conclusion PCT, not being influenced by acute kidney graft rejection but serving as a specific indicator of systemic bacterial infection, could help to discriminate between both types of inflammation.