Post-operative kinetics of procalcitonin after lung transplantation

Post-operative infections are a major complication after lung transplantation (LT). Early bacterial pneumonia worsens the prognosis of LT. Procalcitonin (PCT) has been proposed as an early and rapid laboratory marker of infection and sepsis. PCT could be a useful biomarker of pulmonary infection after LT, but the early kinetics of PCT in this setting are unknown. We evaluated the kinetics of PCT and the impact of respiratory tract infection on PCT concentrations.

Over a 12-month period, PCT concentrations were determined daily in each patient admitted to our ICU for LT. Epidemiologic, clinical, laboratory and outcome data were obtained. A diagnosis of respiratory tract infection was suspected on clinical examination and confirmed by microbiologic culture.

Twenty-six consecutive patients were included and 397 blood samples were obtained (13 [range 4 to 66] samples per patient). Plasma PCT reached a peak in the first 24 hours post-transplantation (5.72 [0.11 to 93.8] ng/ml), with a progressive decline over the first 7 post-operative days. Doubling of plasma PCT levels after an initial decrease was significantly associated with respiratory tract infection in transplanted patients (RR = 4.2 95% CI [1.95 to 9.03]).

A non-specific increase in PCT values was observed during the first week post-LT. In combination with microbiologic cultures, PCT assays may be useful after the first post-operative week as an aid in the diagnosis of bacterial pulmonary infection.