Diagnostic and Prognostic Value of Procalcitonin and C-Reactive Protein in Malnourished Children

Abstract

BACKGROUND: Early recognition of bacterial infections is crucial for their proper management, but is particularly difficult in children with severe acute malnutrition (SAM). The objectives of this study were to evaluate the accuracy of C-reactive protein (CRP) and procalcitonin (PCT) for diagnosing bacterial infections and assessing the prognosis of hospitalized children with SAM, and to determine the reliability of CRP and PCT rapid tests suitable for remote settings. METHODS: From November 2007 to July 2008, we prospectively recruited 311 children aged 6 to 59 months hospitalized with SAM plus a medical complication in Maradi, Niger. Blood, urine, and stool cultures and chest radiography were performed systematically on admission. CRP and PCT were measured by rapid tests and by reference quantitative methods using frozen serum sent to a reference laboratory. RESULTS: Median CRP and PCT levels were higher in children with bacteremia or pneumonia than in those with no proven bacterial infection (P < .002). However, both markers performed poorly in identifying invasive bacterial infection, with areas under the curve of 0.64 and 0.67 before and after excluding children with malaria, respectively. At a threshold of 40 mg/L, CRP was the best predictor of death (81% sensitivity, 58% specificity). Rapid test results were consistent with those from reference methods. CONCLUSIONS: CRP and PCT are not sufficiently accurate for diagnosing invasive bacterial infections in this population of hospitalized children with complicated SAM. However, a rapid CRP test could be useful in these settings to identify children most at risk for dying.

Advances in the diagnosis of pneumonia in children

“…[122][123][124][125][126][127][128][129] Several other biomarkers, including the combination of haptoglobin, tumor necrosis factor (TNF) receptor 2, or interleukin 10, and tissue inhibitor of metalloproteinases 1, 130 have shown promise for the classification of children with bacterial pneumonia but require further evaluation.…”

“…[121][122][123] The reported performance characteristics of procalcitonin versus CRP vary, with no clear evidence that either is superior. 121 124 BTS guidelines recommend against the use of acute phase reactants for distinguishing between bacterial and viral pneumonia, 28 whereas IDSA guidelines recommend that they are not used as the only distinguishing determinant.…”

The Diagnostic Accuracy of Serum Procalcitonin for Bacteremia in Critically Ill Children

“…Additionally, CRP and lactate values were not available for each febrile episode. The performance of PCT may be limited in patients with severe malnutrition, 30 immunodeficiency 31 or chronic kidney disease. 32 The effects of these conditions on PCT were not considered in this study.…”

Serious bacterial infections in febrile young children: Lack of value of biomarkers

“…The clinical profile of these patients varied greatly, and 11 (44.0%) were critically ill, requiring paediatric intensive care unit (PICU) admission. PCT was found to be positive (>0.2 µg/L) [7] in 21 (84.0%) of the 25 patients, 10 (47.6%) of whom were admitted to ICU. Five (50.0%) of these 10 died.…”

“…A C-reactive protein (CRP) value was deemed positive/predictive of bacterial infection if CRP >40 mg/L [6] and procalcitonin (PCT) was positive if >0.2 µg/L. [7] Cerebrospinal fluid (CSF) findings were considered positive based either on biochemistry suggestive of meningitis, or on a positive CSF culture or PCR. [8] Chest radiographs (CXRs) were interpreted by the lead investigator using the World Health Organization (WHO) CXR interpretation methodology.…”