The potential role of procalcitonin in the emergency department management of febrile young adults during a sustained meningococcal epidemic

Clinical and Cost-Effectiveness of Procalcitonin Test for Prodromal Meningococcal Disease-A Meta-Analysis

Background

Despite vaccines and improved medical intensive care, clinicians must continue to be vigilant of possible Meningococcal Disease in children. The objective was to establish if the procalcitonin test was a cost-effective adjunct for prodromal Meningococcal Disease in children presenting at emergency department with fever without source.

Methods and Findings

Data to evaluate procalcitonin, C-reactive protein and white cell count tests as indicators of Meningococcal Disease were collected from six independent studies identified through a systematic literature search, applying PRISMA guidelines. The data included 881 children with fever without source in developed countries.The optimal cut-off value for the procalcitonin, C-reactive protein and white cell count tests, each as an indicator of Meningococcal Disease, was determined. Summary Receiver Operator Curve analysis determined the overall diagnostic performance of each test with 95% confidence intervals. A decision analytic model was designed to reflect realistic clinical pathways for a child presenting with fever without source by comparing two diagnostic strategies: standard testing using combined C-reactive protein and white cell count tests compared to standard testing plus procalcitonin test. The costs of each of the four diagnosis groups (true positive, false negative, true negative and false positive) were assessed from a National Health Service payer perspective. The procalcitonin test was more accurate (sensitivity=0.89, 95%CI=0.76-0.96; specificity=0.74, 95%CI=0.4-0.92) for early Meningococcal Disease compared to standard testing alone (sensitivity=0.47, 95%CI=0.32-0.62; specificity=0.8, 95% CI=0.64-0.9). Decision analytic model outcomes indicated that the incremental cost effectiveness ratio for the base case was £-8,137.25 (US $ -13,371.94) per correctly treated patient.

Conclusions

Procalcitonin plus standard recommended tests, improved the discriminatory ability for fatal Meningococcal Disease and was more cost-effective; it was also a superior biomarker in infants. Further research is recommended for point-of-care procalcitonin testing and Markov modelling to incorporate cost per QALY with a life-time model.

Diagnostic efficacy of activated partial thromboplastin time waveform and procalcitonin analysis in pediatric meningococcal sepsis

OBJECTIVE

A biphasic activated partial thromboplastin time waveform predicts sepsis and disseminated intravascular coagulation in adults. This has not been previously investigated in children. Our aim is to ascertain whether there are changes in the activated partial thromboplastin time waveform in children with meningococcal disease and to compare its diagnostic use with procalcitonin.

SETTING

Alder Hey Children's National Health Service Foundation Trust, Liverpool, UK.

PATIENTS

Thirty-six children admitted to the hospital for the treatment of suspected meningococcal disease had activated partial thromboplastin time waveform and procalcitonin analysis performed at admission. The light transmittance level at 18 secs was used to quantitate the waveform. Severity of disease was assessed using the Glasgow Meningococcal Septicaemia Prognostic Score, Pediatric Risk of Mortality III score, and the Pediatric Logistic Organ Dysfunction score.

MEASUREMENTS AND MAIN RESULTS

Twenty-four children had proven meningococcal disease, 12 had a presumed viral illness, and 20 control subjects were recruited. Transmittance level at 18 secs was lower in children with meningococcal disease and those with a viral illness (p < .0001) and control subjects (p < .0005). Sensitivity and specificity was 0.91 and 0.96 for transmittance level at 18 secs and 0.92 and 1 for procalcitonin in identifying meningococcal disease. There was a significant difference in procalcitonin between children with meningococcal disease and those with a viral illness and control subjects (p < .0005). A negative correlation was found between transmittance level at 18 secs and length of hospital stay (p < .0001), C-reactive protein (p < .0001), procalcitonin (p < .0001), Glasgow Meningococcal Septicaemia Prognostic Score (p < .01), Pediatric Risk of Mortality III score (p < .0001), and Pediatric Logistic Organ Dysfunction score score (p < .0001).

CONCLUSION

The activated partial thromboplastin time waveform is abnormal in children with meningococcal disease and may be a useful adjunct in the diagnosis and management of sepsis in children.

Association of serum procalcitonin with cardiovascular prognosis in coronary artery disease

BACKGROUND

Procalcitonin (PCT) is an established biomarker for the diagnosis of sepsis. Evidence is growing that PCT concentration correlates with the extent of atherosclerosis and prognosis in patients with coronary artery disease (CAD).

METHODS AND RESULTS

A total of 2,131 patients with CAD were followed up for a median of 3.6 years. During follow-up, death from cardiovascular causes was registered in 95 patients and non-fatal myocardial infarction in 85 patients. Median and quartile 1 and 3 are reported for PCT concentration. Patients who died of cardiovascular causes had higher PCT concentrations [0.021 (0.012/0.036) ng/ml vs. 0.015 (0.010/0.023) ng/ml; P<0.0001]. Patients with acute coronary syndrome had increased concentrations of PCT in relation to patients with stable angina [0.016 (0.011/0.027) ng/ml vs. 0.014 (0.009/0.014) ng/ml; P for trend <0.0001]. PCT concentration across quartiles was associated with the event rate (P=0.026; log-rank test) and mortality (P=0.00018). On Cox regression analysis, elevated PCT concentration was related to cardiovascular mortality [hazard ratio (HR), 1.34; 95% confidence interval (CI): 1.08-1.65, P=0.0070], but not to cardiovascular events (HR, 1.09; 95%CI: 0.93-1.28, P=0.28). After adjustment for C-reactive protein (CRP), PCT did not provide additional prognostic information.

CONCLUSIONS

PCT is associated with future cardiovascular mortality in patients with CAD, but PCT is not superior to CRP for prediction of outcome.

Procalcitonin Test in the Diagnosis of Bacteremia: A Meta-analysis

STUDY OBJECTIVE

We seek to evaluate the diagnostic performance of the procalcitonin test for the diagnosis of bacteremia in the emergency department (ED) population.

METHODS

We conducted a search of MEDLINE, bibliographies of previous systemic reviews, and pertinent national meeting research abstracts. We included studies that assessed the diagnostic accuracy of procalcitonin for bacteremia, with blood culture as the reference standard. We included prospective investigations of adults and children with suspected infection studied in the ED or at admission. Two authors independently extracted data and assessed study quality; consensus was reached by conference. The analysis was based on the I2 statistic for heterogeneity, unweighted summary receiver-operating characteristic curve, and random-effects pooled sensitivity and specificity across studies using the same test threshold.

RESULTS

The search yielded 348 publications and 1 unpublished study. Seventeen studies met the inclusion criteria and provided a sample of 2,008 subjects. There was a substantial degree of inconsistency (I2=64%). The unweighted summary receiver-operating characteristic curve provided the best overall estimate of test performance, with an area under the curve of 0.84 (95% confidence interval [CI] 0.75 to 0.90). Sensitivity analysis based on study quality did not significantly change the results. Subgroup analysis including only studies that used a test threshold of 0.5 or 0.4 ng/mL yielded pooled estimates for sensitivity and specificity of 76% (95% CI 0.66 to 0.84) and 70% (95% CI 0.60 to 0.79), respectively.

CONCLUSION

We found the diagnostic performance of the procalcitonin test for identifying bacteremia in ED patients to be moderate. Future research designed to determine the utility of the procalcitonin test as a diagnostic tool used in isolation for detecting bacteremia in ambulatory patients is needed before widespread clinical use.

Experience with MCV-4, a meningococcal, diphtheria toxoid conjugate vaccine against serogroups A, C, Y and W-135

Invasive disease due to Neisseria meningitidis continues to cause debility and death worldwide in otherwise healthy individuals. Disease epidemiology varies globally, but most cases are due to serogroups A, B, C, W-135 or Y. MenactraTM (MCV-4), a quadrivalent, meningococcal diphtheria-conjugate vaccine against serogroups A, C, Y, and W-135, was licensed in the USA for individuals 11-55 years of age. Published results of clinical trials demonstrated robust immune responses that correlate with indicators of protection. MCV-4-induced antibody persist for up to 3 years after administration and anamnestic responses to revaccination. The vaccine was well tolerated; the most common reactions were transient, mild injection-site reactions and headache. MCV-4 should provide significant clinical benefits in the future.

Elevated procalcitonin as a diagnostic marker in meningococcal disease

Patients with meningococcal disease who seek medical attention can create a diagnostic dilemma for clinicians due to the nonspecific nature of the disease's presentation. This study assesses the diagnostic accuracy of procalcitonin levels in the setting of meningococcal disease. Two emergency department cohorts (A and B) were studied between 2002 and 2005, during the current epidemic of serogroup B meningococcal disease in New Zealand. Cohort A consisted of 171 patients, all with confirmed meningococcal disease (84 children, 87 adults). Cohort B consisted of a large (n=1,524) consecutively recruited population of febrile patients who presented to the emergency department, 28 of whom had confirmed meningococcal disease. Within the meningococcal disease cohort (cohort A), the geometric mean procalcitonin level was 9.9 ng/ml, with levels being higher in children than in adults (21.6 vs. 4.6 ng/ml, p=0.01). The overall sensitivity of elevated procalcitonin, using a cutoff of 2.0 ng/ml in children and 0.5 ng/ml in adults, was 0.93 (95%CI: 0.88-0.96). Despite the higher cutoff level for paediatric patients, a trend towards greater sensitivity existed in children (0.96 vs. 0.90; p=0.08). Elevated procalcitonin was correlated with whole blood meningococcal load (r=0.50) and Glasgow Meningococcal Sepsis Prognostic Score (r=0.40). Within the cohort of patients who were febrile on presentation (cohort B), the specificity of elevated procalcitonin in meningococcal disease was 0.85 (95% CI: 0.83-0.87), the positive and negative likelihood ratios were 6.1 and 0.08, respectively, and the sensitivity of elevated procalcitonin (0.93; 95% CI: 0.76-0.99) was corroborated. Measurement of procalcitonin is a useful tool in patients with nonspecific febrile illnesses when the possibility of meningococcal disease is present. The diagnostic accuracy surpasses that of current early laboratory markers, allowing results to be used to guide decisions about patient management.

[Utility of procalcitonin, C-reactive protein and leukocyte count in the detection of meningococcal disease during an epidemic cluster]

OBJECTIVE

To determine the clinical utility of biological markers of the acute phase of bacterial infection (procalcitonin, C-reactive protein and leukocyte count) in invasive meningococcal disease during an epidemic cluster.

PATIENTS AND METHODS

Thirty-six patients with feverish syndrome who visited the emergency unit of our hospital within a 6-month period were studied. In all patients, serum procalcitonin and C reactive protein levels and leukocyte count were determined, and blood culture was performed.

RESULTS

Invasive meningococcal disease, confirmed by blood culture, was found in seven of the 36 patients studied. The most frequent clinical presentation was a feverish syndrome of less than 24 hours of onset, progressing to sepsis in subsequent hours. Comparison of procalcitonin and C reactive protein concentrations in patients with and without meningococcal disease revealed that procalcitonin and C reactive protein levels greater than 10 ng/ml and 49.95 ng/ml respectively had high sensitivity, specificity and predictive values. Procalcitonin levels < 0.5 ng/ml were useful to easily rule out invasive meningococcal disease. In the case of leukocyte count, no value with clinical significance could be established, although counts were higher in patients with invasive meningococcal disease.

CONCLUSIONS

The finding of prolactin levels of < 0.5 ng/ml and/or C-reactive protein levels of < 49.95 ng/ml in children or teenagers with fever of less than 24 hours of onset indicates a low probability of invasive meningococcal disease in epidemic situations.