Procalcitonin levels in preterm newborns: Reference ranges during the first three days of life

BACKGROUND: Sepsis is one of the most important causes of morbidity and mortality in the neonatal period, especially in preterms. Diagnosis is difficult because of specific signs and symptoms. The diagnostic gold standard is blood culture, but its sensibility is low. Much effort has been made to identify early, sensitive, and specific diagnostic markers; among these markers particular attention was paid to procalcitonin. However, reference ranges of serum procalcitonin (PCT) shortly after birth have not been sufficiently studied in healthy preterms, and literature is still contradictory. OBJECTIVES: The aim of the study is to define PCT age-specific reference ranges in the first 72 h of life in uninfected VLBW preterms. METHODS: Serum levels of PCT were assessed for each newborn at birth and every 24 h until the 3rd day of life. The eligible patients were classified into two groups according to their sepsis status. RESULTS: Approximately 343 patients were enrolled; 28 were septic and 315 non-septic. In non-septic infants, 1,015 determinations of PCT values were performed. Our data showed a trend in average value of PCT to increase after birth up to a peak between 24 and 48 h of life and, subsequently, to fall. The average peak value was 15.12 ng/ml achieved at nearly 36 h of life. CONCLUSION: Our study shows a PCT nomogram of healthy preterms, which is different from the one of term newborns. Data agree with what is reported in literature on the reference ranges and trends of PCT in non-septic preterms shortly after birth.