ABSTRACT
BACKGROUND: Procalciton (PCT) is a precursor polypeptide of the hormone calcitonin, produced in C cells of the thyroid. It has been demonstrated that microbial toxins and proinflammatory mediators can cause the release of PCT from tissues and cells in the body. PCT thus has become an important marker in the diagnosis of infection. METHODS: In this retrospective study we analyzed blood samples performed for clinical purposes from the newborns present in our hospital in the year 2019. We developed a database of 1356 PCT values obtained from 224 infants at risk for neonatal infection; we selected those PCT values obtained within 24 hours from a blood sampling for blood culture. RESULTS: Babies with positive blood culture had PCT values more elevated than those with negative blood culture (17.061 ng/mL [C.I. 10.8-23.2] vs. 4.6 ng/mL [C.I. 2.6-6.6]). No statistically significant difference was found between babies with negative blood culture born before or after 37 weeks of gestation. CONCLUSIONS: This paper gives useful data of PCT values in non-infective babies. It is worth to show that the normality values should not be confused with those of older children or adults. Moreover, it shows the reliability of PCT as an infection index.
ABSTRACT
BACKGROUND: The performance of QuantiFERON-TB Gold In-Tube (QTF-IT) in children is under debate, especially in those under 5â¯years of age. Moreover, interpretation of discordant QFT-IT/Tuberculin-Skin-Test (TST) results remains controversial. This study aims at studying the sensitivity of QFT-IT and TST in children with active TB cases and exploring risk factors associated with discordant TST+/QFT-IT-. METHODS: Children consecutively referred to one single pediatric center between 2010 and 2017 for suspected tuberculosis infection (TB) were enrolled. All children underwent clinical evaluation, TST and QFT-IT. Sensitivity of QFT-IT and TST in active TB cases and risk factors associated with discordant TST+/QFT-IT- results were assessed. Uni- and multi-variate logistic regression analyses were performed. RESULTS: Overall, 4631 children (median age 5.67â¯years) were enrolled, and 205 active TB cases were diagnosed (83 microbiologically confirmed). A high QFT-IT sensitivity was observed in children between 2 and 4â¯years of age (95.0%; 95%CI: 85.4-100) and in those between 5 and 18â¯years (89.1%; 95%CI:79.2-99.2) with microbiologically confirmed active TB. However, sensitivity was suboptimal in children younger than 2â¯years (84.6%; 95%CI: 65.0-100). Independent risk factors associated with discordant TST+/QFT-IT- results in children with latent tuberculosis infection (LTBI) were previous BCG vaccination (aOR:2.18; 95%CI:1.33-3.58; pâ¯=â¯0.002), age <2â¯years vs. 5-18â¯years (aOR:7.54; 95%CI:2.52-22.59; pâ¯<â¯0.0001), age 2-4â¯years vs. 5-18â¯years (aOR:4.63; 95%CI:2.66-8.06; pâ¯<â¯0.0001), and investigation for screening rather than for contact with a suspected or confirmed case (aOR:3.58; 95%CI:2.30-5.59; pâ¯<â¯0.0001). CONCLUSION: Our data suggest that QFT-IT might be used as unique assay in children over 2â¯years of age investigated for recent immigration/adoption screening and in cases of recent low risk TB contact. This approach could considerably reduce the number of children undergoing pharmacological treatment. Conversely, both tests are recommended in cases of strong clinical suspicion or high risk TB contact in children less than 5â¯years of age, in order to avoid misdiagnosis.