Serum procalcitonin is not an early marker of pulmonary exacerbation in children with cystic fibrosis

Procalcitonin predicts the severity of cystic fibrosis pulmonary exacerbations and readmissions in adult patients: a prospective cohort study

Patients with cystic fibrosis (CF) experience multiple pulmonary exacerbations throughout their lifetime, resulting in repeated antibiotic exposure and hospital admissions. Reliable diagnostic markers to guide antibiotic treatment in patients with CF, however, are lacking. Given that the CF airway is characterized by persistent and frequent bacterial infection, our goal was to determine if procalcitonin (PCT) could be used as a severity and prognostic marker of CF exacerbation. We enrolled 40 participants at the time of diagnosis of CF pulmonary exacerbation. Inclusion criteria: age ≥19 years with exacerbation requiring antibiotics as determined by the treating physician. Exclusion criteria: antibiotics initiated more than 48 hours prior to enrollment, and pregnancy. Blood samples were collected on enrollment day and after 7-10 days of treatment. Of the 40 patients enrolled, 23 (57.5%) had detectable levels of PCT (≥0.05 ng/mL). PCT levels were significantly associated with pulmonary exacerbation scores (p=0.01) and per cent decrease in forced expiratory volume in 1 second (FEV₁) (p=0.01) compared with the best in the last 12 months. Those who had worsening PCT during treatment had less improvement in FEV₁ (p=0.001) and were more likely to be readmitted to the hospital sooner (p<0.0001). Likewise, those who had a detectable PCT at the time of admission were more likely to be readmitted sooner (p=0.03). PCT elevation during antibiotic treatment is associated with less improvement in FEV₁ and earlier readmission. A detectable PCT level occurs only in more severe CF exacerbations. Multicenter trials are needed to confirm whether PCT may play a role in the clinical care of patients with CF.

A meta-analysis to assess usefulness of procalcitonin-guided antibiotic usage for decision making

Background & objectives:

Development of antibacterial resistance and its association with antibiotic overuse makes it necessary to identify a specific and sensitive biomarker for the diagnosis of bacterial infection and guiding antibiotic therapy. Procalcitonin (PCT), as a sepsis biomarker, may play a role in guiding antibiotics treatment in hospital settings. The aim of the current meta-analysis was to analyze the utility of PCT on various outcomes of interest in inpatients.

Methods:

Different databases were searched for randomized controlled trials comparing PCT-guided therapy with standard therapy in admitted patients with bacterial infections. Twenty six articles were found suitable for full text search and of these, 16 studies were considered finally for data extraction.

Results:

There were no significant differences found in total mortality [pooled odds ratio (OR) 1.04, 95% confidence interval (CI) 0.89-1.22, P=0.63], 28-day mortality (pooled OR 0.97, 95% CI 0.80-1.19, P=0.79), need of Intensive Care Unit admission (OR=0.80, 95% CI 0.59-1.09, P=0.16) and duration of stay in hospital (pooled mean difference −0.01, 95% CI −0.50-0.49, P=0.98) between treatment and control groups. PCT-guided treatment significantly decreased the duration of antibiotic treatment (pooled mean difference −2.79, 95% CI −3.52-−2.06, P<0.00001).

Interpretation & conclusions:

PCT-guided therapy significantly decreased antibiotics exposure and thus treatment cost. However, the hard endpoints did not demonstrate any significant benefits, possibly due to low power to detect differences and/or the presence of comorbidities.

Procalcitonin, erythrocyte sedimentation rate and C-reactive protein in acute pulmonary exacerbations of cystic fibrosis

INTRODUCTION

Acute pulmonary exacerbations of cystic fibrosis (APECF) are a leading cause of morbidity and mortality among patients with cystic fibrosis (CF). APECF require frequent administration of antibiotics and subsequently lead to development of resistant organisms.

OBJECTIVES

The aim of this study was to identify inflammatory markers that may be help identify need for antibiotics and exacerbation as well as predict risk of exacerbations.

METHODS

A total of 17 patients were enrolled, and baseline erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and procalcitonin levels were obtained in addition to obtaining these levels during admissions for APECF.

RESULTS

A total of 28 APECF were recorded. ESR and CRP significantly increased during exacerbation (P < .01 for both). Procalcitonin did not increase during exacerbations. Baseline elevations in ESR and CRP increased risk of an exacerbation (RR = 2.3 and 4.5, respectively).

CONCLUSIONS

ESR and CRP are useful markers for CF exacerbations, as levels rise with exacerbations. Baseline elevations in ESR and CRP were noted to show an increased risk for CF exacerbations. Procalcitonin, in contrast, is not a useful inflammatory marker.

Clinically Promising Biomarkers in Cystic Fibrosis Pulmonary Exacerbations

Cystic fibrosis is a complex genetic disease hallmarked by repetitive infectious exacerbations that leads to destruction of airway architecture, acute on chronic inflammatory changes, and deterioration in lung function. Predicting an exacerbation may help preempt some of these changes by the initiation of swift antibiotic and anti-inflammatory therapy. A search for biomarkers that could predict exacerbations or help guide duration of antibiotic therapy is being aggressively sought. In this review, we discuss the most recent and promising biomarkers that hopefully will assist in the future management of the CF patient.

Systematic review of blood biomarkers in cystic fibrosis pulmonary exacerbations

BACKGROUND

Biomarkers reflective of disease activity in cystic fibrosis (CF) have the potential to improve patient care, particularly during CF pulmonary exacerbations (CFPEs). Although blood-based biomarkers have been studied in CFPE for nearly 3 decades, none have been integrated into routine clinical practice. To facilitate progress in this area, we performed a systematic review evaluating blood-based biomarkers during CFPE.

METHODS

MEDLINE, EMBASE, and CENTRAL were searched to identify relevant studies published from January 1995 to August 2012. We included all full-text studies examining systemic (blood-based) biomarkers to aid in the diagnosis of CFPE, predict outcomes of CFPE, and/or monitor the response to CFPE treatment.

RESULTS

Seventy-eight unique blood-based biomarkers have been studied to date, mainly inflammatory cytokines, acute phase reactants, and markers of oxidative stress. C-reactive protein (CRP) consistently correlated with disease activity, with a statistically significant increase from stable to exacerbation state in five of six studies, and changes in response to CFPE treatment, with a statistically significant decrease from the beginning to the end of CFPE treatment in 18 of 20 studies. Other promising biomarkers of CFPE disease activity include neutrophil elastase antiproteinase complex, IL-6, myeloperoxidase (MPO), lactoferrin, and calprotectin.

CONCLUSIONS

Although there are several blood-based biomarkers with evidence for application within the CFPE setting, CRP has been the most widely studied biomarker demonstrating the potential for clinical usefulness. Further validation studies and clinical trials are required to determine whether blood-based biomarkers can be used to ultimately improve health outcomes in the setting of a CFPE.

Effects of treatment in the levels of circulating cytokines and growth factors in cystic fibrosis and dialyzed patients by multi-analytical determination with a biochip array platform

Chronic inflammatory diseases need non-invasive sensitive, reliable and predictive clinical biomarkers for diagnosis and monitoring therapy. Since inflammation is a complex phenomenon, simultaneous evaluation of different analytes in the same sample may help in defining this complexity and in developing specific anti-inflammatory intervention strategies. In this study, we used a biochip array system capable of measuring 12 cytokines and growth factors (IL-2, IL-4, IL-6, IL-8, IL-10, IL-1 α, IL-1 β, IFN-γ, TNF-α, MCP-1, VEGF, and EGF) in three groups: 97 control subjects; 24 cystic fibrosis (CF) patients before and during the antibiotic treatment (6 and 15days) for acute pulmonary exacerbation as well as 15days after the withdrawal of therapy; 22 children and young adults on chronic hemodialysis (HD) at the beginning and at the end of a standard HD session. CF patients in acute exacerbation displayed higher IL-2, IL-6, VEGF and MCP-1 levels than the control subjects. IL-6 significantly decreased during therapy (P<0.01) but not 15days after the withdrawal of therapy. IL-8 and EGF levels were significantly lower after 15days from the interruption of therapy (P<0.05 and P<0.01 respectively). Regression analysis showed that IL-4 and IL-6 correlated with the amelioration of the respiratory function during therapy. Patients on HD displayed higher IL-6 but lower IL-2, IL-4, IL-8, IFN-γ and EGF levels than control subjects. Serum levels of IL-8, IL-10 and IFN-γ were significantly higher at the end of the HD session (P<0.05 for all three). A biochip array allowed to define a pattern of cytokines/growth factors associated with an acute exacerbation in CF patients and IL-4 and IL-6 as predictors of response to therapy. In younger HD patients, we identified a biomarker pattern which is different from that of older patients. Finally, further studies are warranted to examine the role of these biomarkers in the pathogenesis of complications in HD patients.