Usefulness of serum procalcitonin as a diagnostic biomarker of infection in children with chronic kidney disease

Introduction: Serum procalcitonin (PCT) levels are known to be low in healthy individ­uals in healthy subjects but are increased in patients with a severe bacterial infection. It has not been extensively studied in children with chronic kidney disease (CKD), treated either with hemodialysis (HD) or with renal transplantation. Material and methods: During a 6-month period, blood samples were taken from 102 (55 HD children and 47 renal transplant recipients) children with a strong clinical suspicion of infection. Procalcitonin levels were measured by ELISA. Results: Thirty-four/102 cases had proven infections as defined previously. Children with proven infections had a significantly higher PCT (0.920 ±0.24 ng/ml) than those without (0.456 ±0.53 ng/ml), p = 0.04. The ideal cutoff value derived for serum PCT was 0.5 ng/ml. This threshold value established a sensitivity of 94.1% and a specificity of 87.9%. Conclusions: This study indicates that significantly increased PCT concentration is a promising predictor of systemic bacterial infection in children with CKD, with good sensitivity and specificity. This study proposes that serum PCT is a convenient index of infection in CKD children at a cutoff value of 0.5 ng/ml.