Effect of induction therapy on kinetic of procalcitonin following uncomplicated heart transplantation

BACKGROUND: The aim of the study was to determine the early postoperative kinetics of serum procalcitonin (PCT) levels in uncomplicated heart transplant patients under induction therapy using antithymocyte globulin (ATG). METHODS: PCT serum concentrations were measured for 7 days in 30 adult patients (26 males, 4 females, mean age 54.5 +/- 7.7 years) undergoing uncomplicated orthotopic heart transplantation. Of the 30 patients, 28 received ATG and 2 with the same immunosuppression regimen had no induction therapy. The induction therapy consisted of 100 mg/day ATG and was started 6 hours postoperatively. RESULTS: Mean PCT levels immediately before HTX were <0.3 ng/mL in both groups. After the first ATG infusion patients developed a significant (p < 0.05) elevation in PCT plasma levels without any incidence of infectious disease with peak levels up to 11.7 +/- 19.7 ng/mL on postoperative day (POD) 1. Thereafter values continuously decreased independently of further ATG administration in all patients (6.7 +/- 10.5 ng/mL on POD 3, 3.2 +/- 7.4 ng/mL on POD 5 and 1.2 +/- 3.0 ng/mL on POD 7). In the non-ATG group a mild postoperative rise in the serum PCT was observed. The values peaked on POD 2 with 2.0 +/- 1.6 ng/mL and normalized within four days. CONCLUSIONS: Perioperative administration of ATG is associated with significantly increased PCT levels even in uncomplicated heart transplant recipients. This phenomenon should not be misinterpreted as systemic infection, as systemic inflammatory reaction that seems to be induced by ATG therapy is responsible for increased PCT production.