Mortality is increased by procalcitonin and decreased by an antiserum reactive to procalcitonin in experimental sepsis

Reactive oxygen species induce procalcitonin expression in trigeminal ganglia glia

OBJECTIVE

To examine calcitonin gene-related peptide (CGRP) gene expression under inflammatory conditions using trigeminal ganglia organ cultures as an experimental system. These cultures have increased proinflammatory signaling that may mimic neurogenic inflammation in the migraine state.

BACKGROUND

The trigeminal nerve sends peripheral pain signals to the central nervous system during migraine. Understanding the dynamic processes that occur within the trigeminal nerve and ganglion may provide insights into events that contribute to migraine pain. A neuropeptide of particular interest is CGRP, which can be elevated and play a causal role in migraine. However, most studies have overlooked a second splice product of the Calca gene that encodes calcitonin (CT), a peptide hormone involved in calcium homeostasis. Importantly, a precursor form of CT called procalcitonin (proCT) can act as a partial agonist at the CGRP receptor and elevated proCT has recently been reported during migraine.

METHODS

We used a trigeminal ganglion whole organ explant model, which has previously been demonstrated to induce pro-inflammatory agents in vitro. Quantitative polymerase chain reaction and immunohistochemistry were used to evaluate changes in messenger ribonucleic acid (mRNA) and protein levels of CGRP and proCT.

RESULTS

Whole mouse trigeminal ganglia cultured for 24 hours showed a 10-fold increase in CT mRNA, with no change in CGRP mRNA. A similar effect was observed in ganglia from adult rats. ProCT immunoreactivity was localized in glial cells. Cutting the tissue blunted the increase in CT, suggesting that induction required the close environment of the intact ganglia. Consistent with this prediction, there were increased reactive oxygen species in the ganglia, and the elevated CT mRNA was reduced by antioxidant treatment. Surprisingly, reactive oxygen species were increased in neurons, not glia.

CONCLUSIONS

These results demonstrate that reactive oxygen species can activate proCT expression from the CGRP gene in trigeminal glia by a paracrine regulatory mechanism. We propose that this glial recruitment pathway may occur following cortical spreading depression and neurogenic inflammation to increase CGRP nociceptive actions in migraine.

Procalcitonin predicts mortality in HIV-infected Ugandan adults with lower respiratory tract infections

BACKGROUND AND OBJECTIVE

In low and middle-income countries where HIV infection is prevalent, identifying patients at high risk of dying from lower respiratory tract infections is challenging and validated prognostic models are lacking. Serum procalcitonin may be a useful prognostic tool in these settings. We sought to determine if elevated serum procalcitonin is associated with increased in-hospital mortality and to combine serum procalcitonin with available clinical characteristics to create a clinically useful prognostic model.

METHODS

We conducted a prospective, nested case-control study of 241 HIV-infected adults admitted to Mulago Hospital in Kampala, Uganda with cough ≥2 weeks in duration. We collected demographic and clinical information, baseline serum for procalcitonin analysis, and followed patients to determine in-hospital mortality.

RESULTS

Serum procalcitonin was a strong and independent predictor of inpatient mortality (aOR = 7.69, p = 0.01, sensitivity = 93%, negative predictive value = 97%). Best subset multivariate analysis identified 3 variables that were combined into a prognostic model to risk stratify patients; these variables included respiratory rate ≥30 breaths/minute (aOR = 2.07, p = 0.11), oxygen saturation <90% (aOR = 3.07, p = 0.02), and serum procalcitonin >0.5 ng/ml (aOR = 7.69, p = 0.01). The predicted probability of inpatient mortality ranged from 1% when no variables were present, to 42% when all variables were present.

CONCLUSIONS

Elevated serum procalcitonin >0.5 ng/ml is an independent predictor of in-hospital mortality. Elevated serum procalcitonin, tachypnea, and hypoxemia may be combined into a prognostic model to identify patients at high risk of dying in the hospital. This model may be used to estimate the probability of death and to guide triage and treatment decisions.

Serial quantification of procalcitonin (PCT) predicts clinical outcome and prognosis in patients with community-acquired pneumonia (CAP)

Procalcitonin (PCT), a calcitonin precursor, is commonly measured in the setting of community-acquired pneumonia (CAP). However, the clinical significance of serial PCT changes has not been established. We conducted a prospective observational study of 122 patients with CAP. Thirty-day mortality was the primary endpoint. Secondary endpoints included: (1) initial treatment failure, (2) 30-day mortality and/or initial treatment failure, and (3) intensive care unit (ICU) admission. In subgroup analysis, we classified patients into pneumococcal pneumonia and non-pneumococcal pneumonia groups. The baseline frequency of 30-day mortality was 10.7%. Increases in serum PCT levels from admission to Day 3 were observed with statistically higher frequency in patients with 30-day mortality (P = 0.002). For secondary endpoints, only the 30-day mortality and/or initial treatment failure group was statistically significant (P = 0.007). Subgroup analysis revealed statistically significant changes in the non-pneumococcal pneumonia group (N = 85) across several endpoints, including 30-day mortality (P = 0.001), initial treatment failure (P = 0.013), and 30-day mortality and/or initial treatment failure (P < 0.001). No significant changes in endpoint measurements were found in the pneumococcal pneumonia group (N = 28). Interestingly, serum PCT levels at the time of diagnosis were higher in patients with pneumococcal pneumonia than those with non-pneumococcal pneumonia (P = 0.006), and this positively correlated with disease severity scores for all patients (PCT vs. PSI: R = 0.380, P < 0.001; PCT vs.

A-DROP

R = 0.422, P < 0.001) and for non-pneumococcal pneumonia (PCT vs. PSI: R = 0.468, P < 0.001; PCT vs.

A-DROP

R = 0.448, P < 0.001), but not for pneumococcal pneumonia. In conclusion, serial quantification of PCT can predict clinical outcomes for patients with CAP.

Deletion of the gene encoding calcitonin and calcitonin gene-related peptide α does not affect the outcome of severe infection in mice

Procalcitonin (PCT) is expressed in nonthryoidal tissues of humans during severe infections. Serum PCT levels are measured to diagnose and guide therapy, and there is some evidence that PCT may also contribute to the pathogenesis of sepsis. We tested whether disruption of the gene encoding PCT in mice affected the course of sepsis. Mice with exons 2-5 of the gene encoding calcitonin/calcitonin gene-related polypeptide α (Calca) knocked out and congenic C57BL/6J control mice were challenged with aerosolized Streptococcus pneumoniae or Pseudomonas aeruginosa, or injected intraperitoneally with S. pneumoniae. There were no significant differences in the survival of knockout and control mice in the two pneumonia models, and no significant differences in weight loss, splenic bacterial counts, or blood leukocyte levels in the peritoneal sepsis model. To verify disruption of the Calca gene in knockout mice, the absence of calcitonin in the serum of knockout mice and its presence and inducibility in control mice were confirmed. To evaluate PCT expression in nonthyroidal tissues of control mice, transcripts were measured in multiple organs. PCT transcripts were not significantly expressed in liver or spleen of control mice challenged with aerosolized P. aeruginosa or intraperitoneal endotoxin, and were expressed in lung only at low levels, even though serum IL-6 rose 3,548-fold. We conclude that mice are not an ideal loss-of-function model to test the role of PCT in the pathogenesis of sepsis because of low nonendocrine PCT expression during infection and inflammation. Nonetheless, our studies demonstrate that nonendocrine PCT expression is not necessary for adverse outcomes from sepsis.

Procalcitonin beyond the acute phase: novel biomediator properties?

Since inflammation has been linked to carcinogenic events, discovery of relevant biomarkers may have important preventative implications. Procalcitonin (ProCT) has been shown to be an important prognostic biomarker in severe inflammatory conditions, but there is no data regarding its biomarker role, if any, beyond the acute phase. In a recent study published in BMC Medicine, Cotoi et al. analyzed whether serum ProCT levels in healthy individuals are associated with mortality outcomes. The results are affirmative in that baseline ProCT was shown to be strongly and independently associated with all-cause and cancer mortality and with the incidence of colon cancer in men. By contrast, the study indicated that high sensitivity C-reactive protein was independently associated with cardiovascular mortality but not with cancer mortality in men. Thus, baseline levels of ProCT appear to have prognostic biomarker implications potentially related to its emerging biomediator action(s).

Plasma procalcitonin is associated with all-cause and cancer mortality in apparently healthy men: a prospective population-based study

BACKGROUND

The inflammatory mediator procalcitonin (PCT) has previously been associated with prognosis in myocardial infarction, cancer and sepsis patients. The importance of PCT in the general population is currently unknown. Our aim was to assess the relationship between plasma PCT and the risk of all-cause and cause-specific mortality in apparently healthy individuals with no previous history of cardiovascular disease or cancer.

METHODS

We performed a prospective, population-based study on 3,322 individuals recruited from the Malmö Diet and Cancer cohort, with a median follow-up time of 16.2 years. Plasma PCT, high-sensitivity C-reactive protein (hsCRP), low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglycerides and cystatin C were measured at baseline and a thorough risk factor assessment was performed for all subjects. The primary end-points of the study were all-cause mortality, cancer mortality and cardiovascular mortality.

RESULTS

Men had higher PCT levels compared to women. In Cox proportional hazard models adjusted for age, sex, hypertension, diabetes, plasma lipids, renal function, body mass index and smoking, baseline PCT was associated with all-cause mortality and cancer mortality in men. The hazard ratio (HR) for men with PCT levels within the highest compared with the lowest quartile was 1.52 (95% confidence interval (CI) 1.07 to 2.16; P = 0.024) for all-cause mortality and 2.37 (95% CI 1.36 to 4.14; P = 0.006) for cancer mortality. Additionally, men with increased plasma PCT were found to be at a higher risk to develop colon cancer (HR per 1 SD increase = 1.49 (95% CI 1.13 to 1.95); P = 0.005). In multivariate Cox regression analyses with mutual adjustments for PCT and hsCRP, PCT was independently associated with cancer death (HR per 1 SD increase = 1.28 (95% CI 1.10 to 1.49); P = 0.001) and hsCRP with cardiovascular death (HR per 1 SD increase = 1.42 (95% CI 1.11 to 1.83); P = 0.006) in men. We found no significant correlations between baseline PCT or hsCRP and incident cancer or cardiovascular death in women.

CONCLUSIONS

We disclose for the first time important independent associations between PCT and the risk for all-cause and cancer mortality in apparently healthy men. Our findings warrant further investigation into the mechanisms underlying the relationship between PCT and cancer.

Procalcitonin as a biomarker of acute lower respiratory tract infections

BACKGROUND

Procalcitonin (PCT) has emerged as a promising 'acute phase' biomarker used for diagnosis of acute bacterial infections of the respiratory tract. The introduction of new sensitive PCT assays has facilitated implementation of a new clinical approach to reduce antibiotic use in acute lower respiratory tract infections (LRTIs), without compromising patient safety.

OBJECTIVE

Current state of knowledge on the clinical usefulness of serum PCT measurements for the evaluation of acute LRTIs is presented herein, together with basic information on available rapid diagnostic tests for PCT measurement.

METHODS

During the literature search the emphasis was on PCT use as a diagnostic, monitoring and prognostic tool for acute LRTIs. The acute LRTIs have been defined as acute bronchitis, acute exacerbations of chronic obstructive pulmonary disease or asthma, and pneumonia. Original studies involving patients with these conditions have been considered, and recent articles documenting interventional trials on PCT use for guidance of antimicrobial treatment in LRTIs have been reviewed in particular.

RESULTS/CONCLUSION

When measured with sensitive and rapid assays, PCT has proved to be a good biomarker for acute bacterial LRTIs, which enables an early diagnosis, facilitates therapeutic decisions, and can inform clinicians about the course of disease and prognosis. PCT can become a particularly suitable tool for implementation in an emergency and acute medical care setting.

New markers in pneumonia

Pneumonia is one of the most common causes of death from infectious diseases worldwide, and the most common fatal infection acquired in hospitals. Despite advances in prevention strategies, such as antibiotic therapies and intensive care, significant improvement in the mortality rate is still lacking. This high mortality is largely due to the limitations in current clinical practices and laboratory tests, which delay the timing of adequate antibiotic therapy. In recent years, many indicators (biomarkers) are present in scenarios where infectious pathogens invade into the body. These biomarkers, as reflected in specific biological responses to infections, have been reported to demonstrate the ability to facilitate the diagnosis, risk stratification, and management of pneumonia. This review provides a schematic overview of these new potential biomarkers based on the categories of (1) microorganisms and their derivatives, (2) inflammation mediators, (3) inflammation response proteins, and (4) stress-sensing proteins. In addition, approaches to identifying new biomarkers are also briefly introduced. Although no current biomarker can solely achieve a definitive diagnosis, many of them can be complemented, rather than replaced outright, in routine clinical practices to improve decision-making processes regarding pneumonia.

Are circulating levels of CRP compared to IL-6 and PCT still relevant in intensive care unit patients?1)

C-reactive protein (CRP) currently constitutes one of the most widely used parameters for the diagnosis of infections and inflammatory processes, due to simple methods and low costs. However, in recent years, other parameters, such as interleukin 6 (IL-6) and procalcitonin (PCT), have gained in importance. Although these parameters are presently not established everywhere in clinical routine, they provide significant advantages in the diagnosis and monitoring of inflammatory diseases. For instance, in intensive care, the increase in IL-6 levels may indicate inflammatory complications 24 to 48 h prior to the increase in circulating CRP levels. In contrast to CRP, PCT shows a higher specifity for bacterial infections, which facilitates the diagnosis of bacterial infections and sepsis. PCT measurements further allow assessment of therapeutic success and indicate necessary changes in antibiotic therapy. These points raise the question whether CRP measurements should at least in part be replaced by PCT and/or IL-6. Thus, this review seeks to examine the value of CRP in relation to PCT and IL-6 for the diagnosis of bacterial infections, in therapeutic monitoring, and regarding prognosis in critical care patients.

Procalcitonin in pediatrics

Over the past two decades, the body of literature on the clinical usefulness of procalcitonin (PCT) in adults has grown rapidly. Although this approach has led to increased insight, it has also prompted debate regarding its potential use in diagnosis and management of severe infection. Clinicians, however, are less familiar with the use of PCT in pediatric populations. In this review, we examine PCT as a marker of severe clinical pediatric conditions including its role in systemic inflammation, infection, and sepsis.

Procalcitonin is a specific marker for detecting bacterial infection in patients with rheumatoid arthritis

OBJECTIVE

Rheumatoid arthritis (RA) is a chronic inflammatory disease accompanied by many complications, and serious infections are associated with many of the advanced therapeutics used to treat it. We assessed serum procalcitonin (PCT) levels to distinguish bacterial infection from other complications in patients with RA.

METHODS

One hundred eighteen patients experiencing an RA flare, noninfectious complication of RA or its treatment, nonbacterial infection, or bacterial infection were studied. Serum PCT concentrations were determined with a chemiluminescent enzyme immunoassay.

RESULTS

All patients experiencing an RA flare showed negative PCT levels (≤ 0.1 ng/ml; n = 18). The PCT level was higher in the bacterial infection group (25.8% had levels ≥ 0.5 ng/ml) than in the other 3 groups (0.0-4.3% had levels ≥ 0.5 ng/ml) and the difference was significant among groups (p = 0.003). Conversely, no statistically significant difference was observed among the groups with C-reactive protein (CRP) concentration ≥ 0.3 mg/dl (p = 0.513), white blood cell (WBC) count > 8500/mm(3) (p = 0.053), or erythrocyte sedimentation rate (ESR) > 15 mm/h (p = 0.328). The OR of high PCT level (≥ 0.5 ng/ml) for detection of bacterial infection was 19.13 (95% CI 2.44-149.78, p = 0.005). Specificity and positive likelihood ratio of PCT ≥ 0.5 ng/ml were highest (98.2% and 14.33, respectively) for detection of bacterial infection, although the sensitivity was low (25.8%).

CONCLUSION

Serum PCT level is a more specific marker for detection of bacterial infection than either CRP, ESR, or WBC count in patients with RA. High PCT levels (≥ 0.5 ng/ml) strongly suggest bacterial infection. However, PCT < 0.5 ng/ml, even if < 0.2 ng/ml, does not rule out bacterial infection and physicians should treat appropriately.

Prognostic categorization of intensive care septic patients

Sepsis is one of the leading worldwide causes of morbidity and mortality in critically-ill patients. Prediction of outcome in patients with sepsis requires repeated clinical interpretation of the patients’ conditions, clinical assessment of tissue hypoxia and the use of severity scoring systems, because the prognostic categorization accuracy of severity scoring indices alone, is relatively poor. Generally, such categorization depends on the severity of the septic state, ranging from systemic inflammatory response to septic shock. Now, there is no gold standard for the clinical assessment of tissue hypoxia which can be achieved by both global and regional oxygen extractabilities, added to prognostic pro-inflammatory mediators. Because the technology used to identify the genetic make-up of the human being is rapidly advancing, the structure of 30 000 genes which make-up the human DNA bank is now known. This would allow easy prognostic categorization of critically-ill patients including those suffering from sepsis. The present review spots lights on the main severity scoring systems used for outcome prediction in septic patients. For morbidity prediction, it discusses the Multiple Organ Dysfunction score, the sequential organ failure assessment score, and the logistic organ dysfunction score. For mortality/survival prediction, it discusses the Acute Physiology and Chronic Health Evaluation scores, the Therapeutic Intervention Scoring System, the Simplified acute physiology score and the Mortality Probability Models. An ideal severity scoring system for prognostic categorization of patients with systemic sepsis is far from being reached. Scoring systems should be used with repeated clinical interpretation of the patients’ conditions, and the assessment of tissue hypoxia in order to attain satisfactory discriminative performance and calibration power.

Use of procalcitonin in patients on chronic hemodialysis: procalcitonin is not related with increased serum calcitonin

Objectives. To investigate whether procalcitonin (PCT) could be useful for detecting bacterial infections in patients on hemodialysis (HD) and with increased calcitonin (CT). Methods. This prospective study included 42 males and 34 females on HD. The infection group consisted of 15 patients with proven bacterial infections; the other 61 patients were designated as the noninfection group. Serum C-reactive protein (CRP), interleukin (IL)-6, white blood cell (WBC) count, immature and total neutrophil (I/T) ratio, and CT were measured at the beginning of HD, and serum PCT levels at the beginning of HD and after HD. Results. The mean CT level in the both groups was apparently higher than that of nonchronic kidney disease. Significantly higher values between the infection and noninfection groups were seen for CRP, IL-6, WBC, I/T ratio, PCT, and CT. The PCT value of the area under the receiver operating characteristic curve was 0.921, which was significantly higher than the values for CRP (0.853; P < 0.01), IL-6 (0.739; P < 0.01), WBC (0.692; P < 0.01), and I/T ratio (0.584; P < 0.01). Conclusions. PCT was useful marker of bacterial infection in patients on HD and with increased CT. PCT levels should be determined before HD.

Procalcitonin-guided antibiotic treatment of respiratory tract infections in a primary care setting: are we there yet?

Clinical signs of infection do not allow for correct identification of bacterial and viral aetiology in acute respiratory infections. A valid tool to assist the clinician in identifying patients who will benefit from antibiotic therapy, as well as patients with a potentially serious infection, could greatly improve patient care and limit excessive antibiotic prescriptions. Procalcitonin is a new marker of suspected bacterial infection that has shown promise in guiding antibiotic therapy in acute respiratory tract infections in hospitals without compromising patient safety. Procalcitonin concentrations in primary care are low and can be used primarily to rule out serious infection. However, procalcitonin measurement should not be used as the sole basis for clinical decisions; clinical skills are prerequisites for the correct use of this new tool in practice. At present there is no point-of-care test for procalcitonin with acceptable precision, severely hampering its application in primary care. This article reviews the physiology of procalcitonin, describes the assays available for its measurement, evaluates the present evidence from primary care on its use to identify correctly patients who are likely to benefit from antibiotic treatment and to rule out serious infections, and comments on further research to determine a future role for procalcitonin in primary care.

Procalcitonin neutralizes bacterial LPS and reduces LPS-induced cytokine release in human peripheral blood mononuclear cells

BACKGROUND

Procalcitonin (PCT) is a polypeptide with several cationic aminoacids in its chemical structure and it is a well known marker of sepsis. It is now emerging that PCT might exhibit some anti-inflammatory effects. The present study, based on the evaluation of the in vitro interaction between PCT and bacterial lipopolisaccharide (LPS), reports new data supporting the interesting and potentially useful anti-inflammatory activity of PCT.

RESULTS

PCT significantly decreased (p < 0.05) the limulus amoebocyte lysate (LAL) assay reactivity of LPS from both Salmonella typhimurium (rough chemotype) and Escherichia coli (smooth chemotype). Subsequently, the in vitro effects of PCT on LPS-induced cytokine release were studied in human peripheral blood mononuclear cells (PBMC). When LPS was pre-incubated for 30 minutes with different concentrations of PCT, the release of interleukin-10 (IL-10) and tumor necrosis factor alpha (TNFα) by PBMC decreased in a concentration-dependent manner after 24 hours for IL-10 and 4 hours for TNFα. The release of monocyte chemotactic protein-1 (MCP-1) exhibited a drastic reduction at 4 hours for all the PCT concentrations assessed, whereas such decrease was concentration-dependent after 24 hours.

CONCLUSIONS

This study provides the first evidence of the capability of PCT to directly neutralize bacterial LPS, thus leading to a reduction of its major inflammatory mediators.

Immune regulation of procalcitonin: a biomarker and mediator of infection

Procalcitonin (PCT) has recently emerged as a powerful biomarker for an early and accurate diagnosis of bacterial infection. Here we summarize our current understanding of the expression pathways of PCT, its potential cellular sources including immune cells, and factors inducing its secretion. Also addressed is the significance of increased blood PCT concentration, which may allow this molecule not only to act as a clinical biomarker but also as an active participant in the development and progression of infectious processes. Experimental approaches to delineate a better understanding of PCT functions, molecular pathways that modulate its expression and therapeutic opportunities to curtail its biological actions are discussed, as well.

Intravenous immunoglobulin prevents release of proinflammatory cytokines in human monocytic cells stimulated with procalcitonin

OBJECTIVE

The aim of this study was to investigate whether the stimulation of monocytic cells with procalcitonin (PCT) results in the release of proinflammatory cytokines. The effects of intravenous immunoglobulin (IVIG) on the production of cytokines from the cells stimulated with PCT were also studied.

MATERIALS AND METHODS

Cultured monocytic cells [THP-1 cells treated with phorbol myristate acetate or peripheral blood mononuclear cells (PBMCs)] were stimulated with PCT. The protein levels of proinflammatory cytokines [tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6 and high mobility group box-1] in the culture supernatants were determined by ELISA kits. The concentration of PCT-specific IgG antibody in IVIG was measured using a specific ELISA.

RESULTS

PCT induced the release of cytokines from THP-1 cells in a time- and dose-dependent manner. IVIG inhibited the release of cytokines from the cells stimulated with PCT. It was confirmed that IVIG also inhibited TNF-α release in the same dose range for PBMCs stimulated with PCT. The presence of PCT-specific IgG antibody was detected in the tested IVIG, which might be one of the mechanisms.

CONCLUSIONS

PCT induced the release of proinflammatory cytokines from THP-1 cells and PBMCs. The function of PCT was prevented by the presence of IVIG.

[Prognostic value of procalcitonin, C-reactive protein and leukocytes in septic shock]

OBJECTIVES

This study evaluates the potential prognostic value of serial measurements of different biomarkers (procalcitonin [PCT], C-reactive protein and leukocytes [CRP]) in septic shock patients.

DESIGN

Prospective observational study.

SETTING

Intensive care unit of a third-level University Hospital.

PATIENTS

The study comprised a total of 88 septic shock patients defined using the 2001 Consensus Conference SCCM/ESICM/ACCP/ATS/SIS criteria. The PCT, CRP and leukocytes were recorded on admission to the ICU and again 72 hours after admission.

INTERVENTIONS

None.

RESULTS

Those patients with increasing procalcitonin levels showed higher hospital mortality than those with a decreasing levels (58.8% vs. 15.4%, P<0.01). No such effect was observed in relation to C-reactive protein or leukocytes. The best area under the curve for prognosis was for procalcitonin clearance (0.79). A procalcitonin clearance of 70% or higher offered a sensitivity and specificity of 94.7% and 53%, respectively.

CONCLUSIONS

Serial procalcitonin measurements are more predictive of the prognosis of septic shock patients than single measurements of this parameter. The prognostic reliability of the latter is also better than in the case of C-reactive protein and leukocytes. The application of serial procalcitonin measurements may allow the identification of those septic patients at increased mortality risk, and help improve their treatment.

Procalcitonin gene expression after LPS stimulation in the porcine animal model

Procalcitonin (PCT), recognised as a marker of sepsis, was investigated in a porcine model of endotoxic shock. The results showed that continuous IV infusion (1-4 h) of LPS (40 μg/kg) in pigs was able to induce a generalised increase of PCT expression in lung, heart, kidney and liver. The increase in PCT was significant only in kidney and was accompanied by an increase in IL-6 gene expression. In vitro results demonstrated that peripheral blood mononuclear cells (PBMCs), as well as endothelial cells, were potentially capable of contributing to in vivo extrathyroidal PCT production. These findings support previous data from pigs concerning the occurrence of widespread activation of PCT extrathyroidal gene expression during endotoxic shock in pigs. Nevertheless, the levels of PCT detected were very low, suggesting the need for additional studies to validate the pig as a reliable animal model for investigating the role of PCT in sepsis.

Procalcitonin as a biomarker in respiratory tract infection

Serum procalcitonin (PCT) levels rapidly increase in patients with invasive bacterial disease. PCT levels increase faster than do C-reactive protein levels. Furthermore, a rapid decrease in the PCT level is supporting evidence that the source of the bacterial infection is responding to clinical management. In patients with community-acquired bacterial pneumonia, sequential PCT levels are useful as a guide to shorter courses of antimicrobial therapy. With use of emerging multiplex real-time polymerase chain reaction platforms for the detection of viral and bacterial respiratory pathogens, it should be possible to critically assess whether an elevated serum PCT level is a valid biomarker of invasive bacterial infection.

Glucose-dependent insulinotropic polypeptide (GIP) induces calcitonin gene-related peptide (CGRP)-I and procalcitonin (Pro-CT) production in human adipocytes

CONTEXT

Increased plasma levels of glucose-dependent insulinotropic polypeptide (GIP), calcitonin CT gene-related peptide (CGRP)-I, and procalcitonin (Pro-CT) are associated with obesity. Adipocytes express functional GIP receptors and the CT peptides Pro-CT and CGRP-I. However, a link between GIP and CT peptides has not been studied yet.

OBJECTIVE

The objective of the study was the assessment of the GIP effect on the expression and secretion of CGRP-I and Pro-CT in human adipocytes, CGRP-I and CT gene expression in adipose tissue (AT) from obese vs. lean subjects, and plasma levels of CGRP-I and Pro-CT after a high-fat meal in obese patients.

DESIGN AND PARTICIPANTS

Human preadipocyte-derived adipocytes, differentiated in vitro, were treated with GIP. mRNA expression and protein secretion of CGRP-I and Pro-CT were measured. Human CGRP-I and CT mRNA expression in AT and CGRP-I and Pro-CT plasma concentrations were assessed.

RESULTS

Treatment with 1 nm GIP induced CGRP-I mRNA expression 6.9 ± 1.0-fold (P < 0.001 vs. control) after 2 h and CT gene expression 14.0 ± 1.7-fold (P < 0.001 vs. control) after 6 h. GIP stimulated CGRP-I secretion 1.7 ± 0.2-fold (P < 0.05 vs. control) after 1 h. In AT samples of obese subjects, CGRP-I mRNA expression was higher in sc AT (P < 0.05 vs. lean subjects), whereas CT expression was higher in visceral AT (P < 0.05 vs. lean subjects). CGRP-I plasma levels increased after a high-fat meal in obese patients.

CONCLUSION

GIP induces CGRP-I and CT expression in human adipocytes. Therefore, elevated Pro-CT and CGRP-I levels in obesity might result from GIP-induced Pro-CT and CGRP-I release in AT and might be triggered by a high-fat diet. How these findings relate to the metabolic complications of obesity warrants further investigations.

Epigenetic regulation of the calcitonin gene-related peptide gene in trigeminal glia

BACKGROUND

The neuropeptide calcitonin gene-related peptide (CGRP) plays a key role in migraine. CGRP gene expression involves an enhancer that is active in neurons, yet inactive in glia. In this report, we analyze epigenetic modifications that allow enhancer activation in glia.

METHODS

DNA methylation and histone acetylation states were measured in rat and human- model cell lines and primary cultures of rat trigeminal ganglia glia. The functional consequence of altering the chromatin state was determined by quantitative measurements of both calcitonin (CT) and CGRP mRNAs.

RESULTS

A hypermethylated CpG island flanking the enhancer was identified in glia and non-expressing cell lines. In addition, the chromatin was hypoacetylated. Treatment with the DNA methylation inhibitor 5-aza-2'-deoxycytidine induced CT mRNA ~30-fold in glial cultures. Treatment with a histone deacetylase inhibitor alone had little effect; however, the combination of inhibitors yielded a synergistic ~80-fold increase in CT and ~threefold increase in CGRP mRNA. Treated glia contained CT precursor (pro-CT) immunoreactivity.

CONCLUSIONS

Epigenetic modulation is sufficient to induce the CGRP gene in glia. Because the CGRP gene is systemically activated by inflammatory conditions, this suggests that glial pro-CT may be an unexplored biomarker during migraine.

Immunoneutralization of the aminoprocalcitonin peptide of procalcitonin protects rats from lethal endotoxaemia: neuroendocrine and systemic studies

Severe sepsis and septic shock are an important cause of mortality and morbidity. These illnesses can be triggered by the bacterial endotoxin LPS (lipopolysaccharide) and pro-inflammatory cytokines, particularly TNF-α (tumour necrosis factor-α) and IL (interleukin)-1β. Severity and mortality of sepsis have also been associated with high concentrations of N-PCT (aminoprocalcitonin), a 57-amino-acid neuroendocrine peptide derived from ProCT (procalcitonin). Previous studies in a lethal model of porcine polymicrobial sepsis have revealed that immunoneutralization with IgG that is reactive to porcine N-PCT significantly improves short-term survival. To explore further the pathophysiological role of N-PCT in sepsis, we developed an antibody raised against a highly conserved amino acid sequence of human N-PCT [N-PCT-(44-57)]. This sequence differs by only one amino acid from rat N-PCT. First, we demonstrated the specificity of this antibody in a well-proven model of anorexia induced in rats by central administration of human N-PCT-(1-57). Next we explored further the therapeutic potential of anti-N-PCT-(44-57) in a rat model of lethal endotoxaemia and determined how this immunoneutralization affected LPS-induced lethality and cytokine production. We show that this specific antibody inhibited the LPS-induced early release of TNF-α and IL-1β and increased survival, even if treatment began after the cytokine response had occurred. In addition, anti-N-PCT-(44-57) may increase long-term survival in LPS-treated rats by up-regulating the late production of counter-regulatory anti-inflammatory mediators such as ACTH (adrenocorticotropic hormone) and IL-10. In conclusion, these results support N-PCT as a pro-inflammatory factor in both the early and the late stages of lethal endotoxaemia, and suggest anti-N-PCT as a candidate for septic shock therapy.

Immunoneutralization of procalcitonin or its component peptides: a promising treatment of sepsis

Sepsis and the severe systemic response syndrome are very common illnesses that are responsible for a great amount of morbidity and death. These closely related conditions are characterized by a remarkable increase in the prohormone ProCT (procalcitonin). ProCT is both a marker of sepsis and a harmful mediator of the disease. In the present issue of Clinical Science, in a study in rats with endotoxin shock, Tavares and Miñano used an antibody to a segment of N-ProCT (aminoprocalcitonin) that is part of the ProCT molecule, and confirmed that immunoneutralization of ProCT saves the animals from this severe illness. Furthermore, they extensively studied the epiphenomena associated with this immunoneutralization.

Exogenous procalcitonin evokes a pro-inflammatory cytokine response

OBJECTIVE AND DESIGN

Procalcitonin (ProCT) is increased in serum of septic patients and those with systemic inflammation. Endogenous levels of ProCT might influence the response of polymorphonuclear leukocytes (PMNs), independently of endotoxin, in clinical disease.

SUBJECTS

Healthy human volunteers.

TREATMENT

Recombinant human ProCT (rhProCT).

METHODS

Whole blood and PMNs were exposed in vitro to exogenous rhProCT. Interleukin (IL)-6, IL-8, IL-10, IL-13, tumor necrosis factor-alpha (TNFα), IL-1β, and macrophage inflammatory protein (MIP)-1β (pg/ml) were measured by multiplex suspension bead-array immunoassay, and migration and phagocytosis were measured in PMNs.

RESULTS

In a whole-blood model, a dose-dependent increase in IL-6, TNFα, and IL-1β of the cell-free supernatant was noted. Pre-incubation with ProCT, at doses consistent with clinical sepsis, resulted in a decrease in PMN migration without alteration in phagocytosis of Staphylococcus aureus or indirect measurements of bacterial killing.

CONCLUSION

Clinically relevant levels of ProCT influence immunologic responses that may contribute to systemic inflammatory response and septic shock.

Procalcitonin for guidance of antibiotic therapy

Procalcitonin is a surrogate biomarker for estimating the likelihood of a bacterial infection. Procalcitonin-guided initiation and termination of antibiotic therapy is a novel approach utilized to reduce antibiotic overuse. This is essential to decrease the risk of side effects and emerging bacterial multiresistance. Interpretation of procalcitonin levels must always comprise the clinical setting and knowledge about assay characteristics. Only highly sensitive procalcitonin assays should be used in clinical practice and cut-off ranges must be adapted to the disease and setting. Highly sensitive procalcitonin measurements, embedded in diagnosis-specific clinical algorithms, have been shown to markedly reduce the overuse of antibiotic therapy without increasing risk to patients in 11 randomized controlled trials including over 3500 patients from different European countries. In primary care and emergency department patients with mild and mostly viral respiratory infections (acute bronchitis), the initial prescription of antibiotics was reduced by 30-80%. In hospitalized and more severely ill patients with community-acquired pneumonia and sepsis, the main effect was a reduction of the duration of antibiotic courses by 25-65%. This review aims to provide physicians with an overview of the strengths and limitations of procalcitonin guidance for antibiotic therapy when used in different clinical settings and in patients with different underlying infections.

Multiple endocrine neoplasia type 2

Multiple endocrine neoplasia type 2 (MEN 2) is an autosomal dominant cancer syndrome with major components of medullary thyroid carcinoma (MTC), pheochromocytoma and hyperparathyroidism. The disease is caused by germline mutations of the RET proto-oncogene. Subtypes of MEN 2 include MEN 2A, MEN 2B and familial MTC (FMTC) which differ in pattern of additional lesions or--in FMTC--lack of pheochromocytoma. In 2009, after extensive review of the literature, the guidelines of the American Thyroid Association made several recommendations regarding clinical and genetic diagnostic testing and treatment options. In this article, the recently published literature is reviewed and concerns regarding future perspectives are added. In particular, a critical handling of rare DNA variants and double mutations is necessary. Up to now, mutation-specific risk profiles and mutation-associated treatment recommendations are unavailable. We emphasise the need for approved centres for treatment of patients affected by MEN 2, not only adults but young children as well. As a high level of skill is required for endoscopic adrenal-sparing surgery, surgeons should declare their expertise before operating such patients. Registry-based follow-up should be mandatory including documentation of short- and long-term outcome in order to provide valid data for future counselling of patients with MEN 2.

Use of plasma procalcitonin levels as an adjunct to clinical microbiology

Procalcitonin (PCT) is synthesized by a large number of tissues and organs in response to invasion by pathogenic bacteria, fungi, and some parasites. Current PCT assays are rapid, specific, and of sufficient sensitivity to detect increases in PCT serum levels within 4 to 6 h of initiation of infection. Clinically, PCT levels may help in decisions regarding the need for empirical antibiotic therapy, "source control" of infection, and duration of antibiotic therapy. The addition of PCT levels to bacterial culture and viral detection results can assist with the separation of colonization and invasion by pathogenic bacteria.

The era of molecular and other non-culture-based methods in diagnosis of sepsis

Sepsis, a leading cause of morbidity and mortality throughout the world, is a clinical syndrome with signs and symptoms relating to an infectious event and the consequent important inflammatory response. From a clinical point of view, sepsis is a continuous process ranging from systemic inflammatory response syndrome (SIRS) to multiple-organ-dysfunction syndrome (MODS). Blood cultures are the current "gold standard" for diagnosis, and they are based on the detection of viable microorganisms present in blood. However, on some occasions, blood cultures have intrinsic limitations in terms of sensitivity and rapidity, and it is not expected that these drawbacks will be overcome by significant improvements in the near future. For these principal reasons, other approaches are therefore needed in association with blood culture to improve the overall diagnostic yield for septic patients. These considerations have represented the rationale for the development of highly sensitive and fast laboratory methods. This review addresses non-culture-based techniques for the diagnosis of sepsis, including molecular and other non-culture-based methods. In particular, the potential clinical role for the sensitive and rapid detection of bacterial and fungal DNA in the development of new diagnostic algorithms is discussed.

Serum procalcitonin in systemic autoimmune diseases--where are we now?

OBJECTIVES

To review the current evidence regarding the value of measuring procalcitonin (PCT) levels in patients with systemic autoimmune diseases, with a focus on the evidence for diagnostic and analytical performance of this biomarker. A brief description of the pathophysiological basis of this biomarker is also included.

METHODS

Using PubMed from the National Library of Medicine, relevant English literature on PCT in patients with different systemic autoimmune diseases, from 1990 to 2009, was reviewed. The search used keywords referring to procalcitonin and systemic lupus erythematosus, antineutrophil cytoplasmic antibody-associated systemic vasculitis, Goodpasture syndrome, rheumatoid arthritis, and giant cell arteritis.

RESULTS

When used in the appropriate clinical setting, the measurement of serum PCT levels is valuable as a marker of severe systemic bacterial and fungal infections and sepsis. Information regarding plasma PCT levels in patients with active underlying systemic autoimmune diseases is limited, primarily from observational studies and case series, with considerable variability of patient characteristics and clinical settings. In the detection of systemic infection concomitant with autoimmune diseases, PCT had a diagnostic sensitivity of 53 to 100% and a specificity of 84 to 97% (depending on the selection criteria) and was superior to other inflammatory markers tested. Most of the studies used a semiquantitative test for PCT measurement (functional assay sensitivity <0.5 ng/mL), which can explain the low sensitivity of the test. PCT levels were not significantly affected by renal function abnormalities or immunosuppressive agents. Although high PCT levels commonly occurred with infection, elevated levels of PCT could be found in patients with vasculitis without evidence of infection, often correlated with high disease activity scores.

CONCLUSIONS

Significantly elevated PCT levels offer good specificity and sensitivity for systemic infection in patients with systemic autoimmune diseases, regardless of the use of corticosteroids or immunosuppressive agents. PCT measurement may add to diagnostic accuracy in patients with systemic autoimmune diseases who present with a febrile illness, especially when highly sensitive PCT assays and specific PCT cutoff ranges are used in a predefined clinical setting (reflecting the likelihood of infection versus an autoimmune disease flare). However, there are limitations when using this biomarker in patients with systemic autoimmune diseases. PCT levels should not replace the necessary extensive diagnostic workup, which should include a thorough history and physical examination, combined with appropriate immunological, microbiological, radiological, and histological data.

Procalcitonin in sepsis and systemic inflammation: a harmful biomarker and a therapeutic target

The worldwide yearly mortality from sepsis is substantial, greater than that of cancer of the lung and breast combined. Moreover, its incidence is increasing, and its response to therapy has not appreciably improved. In this condition, the secretion of procalcitonin (ProCT), the prohormone of calcitonin, is augmented greatly, attaining levels up to thousands of fold of normal. This hypersecretion emanates from multiple tissues throughout the body that are not traditionally viewed as being endocrine. The serum values of ProCT correlate with the severity of sepsis; they recede with its improvement and worsen with exacerbation. Accordingly, as highlighted in this review, serum ProCT has become useful as a biomarker to assist in the diagnosis of sepsis, as well as related infectious or inflammatory conditions. It is also a useful monitor of the clinical course and prognosis, and sensitive and specific assays have been developed for its measurement. Moreover, it has been demonstrated that the administration of ProCT to septic animals greatly increases mortality, and several toxic effects of ProCT have been elucidated by in vitro experimental studies. Antibodies have been developed that neutralize the harmful effects of ProCT, and their use markedly decreases the symptomatology and mortality of animals that harbour a highly virulent sepsis analogous to that occurring in humans. This therapy is facilitated by the long duration of serum ProCT elevation, which allows for a broad window of therapeutic opportunity. An experimental groundwork has been established that suggests a potential applicability of such therapy in septic humans.

Procalcitonin as a marker of severe bacterial infection in children in the emergency department

Procalcitonin, the prohormone of calcitonin, is a relatively new and innovative marker of bacterial infection that has multiple potential applications in the pediatric emergency department. In healthy individuals, circulating levels of procalcitonin are generally very low (<0.05 ng/mL), but in the setting of severe bacterial infection and sepsis, levels can increase by hundreds to thousands of fold within 4 to 6 hours. Although the exact physiologic function of procalcitonin has not been determined, the consistent response and rapid rise of this protein in the setting of severe bacterial infection make procalcitonin a very useful biomarker for invasive bacterial disease. In Europe, serum procalcitonin measurements are frequently used in the diagnosis and the management of patients in a variety of clinical settings. To date, the use of procalcitonin has been limited in the United States, but this valuable biomarker has many potential applications in both the pediatric emergency department and the intensive care unit. The intent of this article is to review the history of procalcitonin, describe the kinetics of the molecule in response to bacterial infection, describe the laboratory methods available for measuring procalcitonin, examine the main causes of procalcitonin elevation, and evaluate the potential applications of procalcitonin measurements in pediatric patients.

Procalcitonin values after dialysis is closely related to type of dialysis membrane

BACKGROUND

Infections account for considerable morbidity and mortality in patients with chronic renal failure undergoing hemodialysis (HD). Diagnosis of infection in HD patients is challenging because the most used laboratory parameters may be increased even in the absence of infection. In this setting, procalcitonin (PCT) could be useful for detection of systemic bacterial infections.

METHODS

We measured high sensitivity C Reactive Protein (hsCRP) and PCT serum levels before and immediately after dialysis in 44 HD patients (22 treated with high- and 22 with low-flux membranes), without history of infections.

RESULTS

Patients on HD by high-flux membranes, but not by low-flux membranes, displayed mean PCT values significantly decreased after dialysis (high-flux: 0.50 vs. 0.26 ng/mL, p=0.005; low-flux: 0.41 vs. 0.42 ng/mL, p=0.863). HsCRP levels were unchanged. HsCRP correlated with PCT values both before and after HD only in patients on HD by low-flux membranes (r=0.51 and 0.47 before and after HD respectively; p<0.05).

CONCLUSIONS

Although PCT is considered a sensitive and specific diagnostic and prognostic marker of systemic bacterial infection, we suggest that specific reference ranges might be developed in patient with impaired renal function, also showing that and its clinical usefulness might be limited in patients undergoing HD with high-flux membranes.

Method for the Selective Measurement of Amino-Terminal Variants of Procalcitonin

Background: Procalcitonin (PCT) is an established marker for diagnosing and monitoring bacterial infections. Full-length PCT [116 amino acids that make up procalcitonin (PCT1–116)] can be truncated, leading to des-Ala-Pro-PCT (des-Alanin-Prolin-Procalcitonin; PCT3–116). Current immunoassays for PCT (“total PCT”) use antibodies directed against internal epitopes and are unable to distinguish amino-terminal PCT variants. Here we describe the development of monoclonal antibodies recognizing the amino-termini of PCT1–116 and PCT3–116 and their use in the selective measurement of these PCT species.

Methods: With newly developed monoclonal antibodies against the amino-termini of PCT1–116 and PCT3–116, and an antibody against the katacalcin moiety of PCT, we developed and characterized immunoluminometric assays for the 2 PCT peptides. We comparatively assessed the kinetics of PCT variants in a human endotoxemia model.

Results: Monoclonal antibodies against the amino-termini of PCT1–116 and PCT3–116 showed &lt;1% cross-reactivity with other PCT-related peptides. The sandwich assays for PCT1–116 and PCT3–116 had functional assay sensitivities of 5 and 1.2 pmol/L, respectively, and exhibited recoveries within 20% of expected values. Plasma PCT1–116 was stable for 6 h at 22 °C and 24 h at 4 °C, and PCT3–116 was stable for at least 24 h at both temperatures. During experimental endotoxemia in healthy people, both PCT1–116 and PCT3–116 increased early in parallel with total PCT, but further increases in PCT1–116 were significantly slower than for PCT3–116 (P = 0.0049) and total PCT (P = 0.0024).

Conclusions: The new assays selectively measure PCT1–116 and PCT3–116. Both PCT species increase early during endotoxemia but differ in their kinetics thereafter. The selective measurement of PCT species with different in vivo kinetics may be useful in improving PCT-guided therapies.

No association between CALCA polymorphisms and clinical outcome or serum procalcitonin levels in German polytrauma patients

PURPOSE

Procalcitonin (PCT) is accepted to be a relevant prognostic marker for the development of clinical complications in multiple trauma patients. Therefore, a prospective cohort study was conducted to investigate whether polymorphisms in the calcitonin (CALCA) gene are associated with PCT levels and posttraumatic complications.

METHODS

During a 14day observation period, blood samples were drawn once daily for systemic PCT concentrations in multiple trauma patients (Injury Severity Score >16). For analysis of allele frequencies, genotype distribution and PCT concentrations polytraumatized patients were separated, according to the development of SIRS, sepsis, septic shock, ARDS, MODS and mortality. Furthermore, association between CALCA polymorphisms and PCT plasma concentrations was assessed.

RESULTS

One hundred thirty seven patients with a mean ISS of 29.2+/-12.1 were included. When trauma patients were grouped according to different posttraumatic complications no association with CALCA SNPs was observed. Additionally, no association was found between CALCA polymorphisms and systemic PCT levels.

CONCLUSION

CALCA polymorphisms are unlikely to influence clinical outcome in polytraumatized patients. Effects of microbial and inflammatory mediators, as well as other risk factors (gender, age, etc.) seem to have a more significant influence on the transcriptional regulation of CALCA and on PCT plasma concentrations than CALCA polymorphisms.

Serum procalcitonin at the time of admission to the ICU as a predictor of short-term mortality

OBJECTIVE

This purpose of this study was to determine if serum procalcitonin (PCT) concentration at the time of admission to the ICU is a predictor of all-cause short-term mortality.

DESIGN AND METHODS

This prospective cross-sectional study was conducted over a 16-month period with 86 consecutive critically ill patients. The semi-quantitative PCT-Q test was performed and APACHE II scores and C-reactive protein (CRP) concentrations were determined within 24 h of admission.

RESULTS

PCT-Q test value was a better predictor of all-cause short-term mortality than CRP value or APACHE II score. PCT > or = 10 ng/mL was highly and independently correlated with mortality. Use of PCT-Q > or = 10 ng/mL was superior to use of APACHE II > or = 25 or CRP > or = 10 mg/dL as a predictor of poor outcome.

CONCLUSIONS

A PCT-Q value > or = 10 ng/mL obtained at the time of admission to the ICU is a strong predictor of short-term mortality.

Biomarkers: diagnosis and risk assessment in sepsis

Prompt diagnosis, intervention, and risk assessment are critical in caring for septic patient but remain difficult with currently available methods. Biomarkers may become useful adjuncts to clinicians and ultimately serve as targets for future therapeutic trials in sepsis. The most relevant markers are reviewed in this article, including interleukin-6, C-reactive protein, procalcitonin, triggering receptor expressed on myeloid cells-1, and biomarker panels.

Procalcitonin kinetics within the first days of sepsis: relationship with the appropriateness of antibiotic therapy and the outcome

Introduction

Management of the early stage of sepsis is a critical issue. As part of it, infection control including appropriate antibiotic therapy administration should be prompt. However, microbiological findings, if any, are generally obtained late during the course of the disease. The potential interest of procalcitonin (PCT) as a way to assess the clinical efficacy of the empirical antibiotic therapy was addressed in the present study.

Methods

An observational cohort study including 180 patients with documented sepsis was conducted in our 15-bed medical intensive care unit (ICU). Procalcitonin measurement was obtained daily over a 4-day period following the onset of sepsis (day 1 (D1) to D4). The PCT time course was analyzed according to the appropriateness of the first-line empirical antibiotic therapy as well as according to the patient outcome.

Results

Appropriate first-line empirical antibiotic therapy (n = 135) was associated with a significantly greater decrease in PCT between D2 and D3 (ΔPCT D2–D3) (-3.9 (35.9) vs. +5.0 (29.7), respectively; P < 0.01). In addition, ΔPCT D2–D3 was found to be an independent predictor of first-line empirical antibiotic therapy appropriateness. In addition, a trend toward a greater rise in PCT between D1 and D2 was observed in patients with inappropriate antibiotics as compared with those with appropriate therapy (+5.2 (47.4) and +1.7 (35.0), respectively; P = 0.20). The D1 PCT level failed to predict outcome, but higher levels were measured in the nonsurvivors (n = 51) when compared with the survivors (n = 121) as early as D3 (40.8 (85.7) and 21.3 (41.0), respectively; P = 0.04). Moreover, PCT kinetics between D2 and D3 were also found to be significantly different, since a decrease ≥ 30% was expected in the survivors (log-rank test, P = 0.04), and was found to be an independent predictor of survival (odds ratio = 2.94; 95% confidence interval 1.22 to 7.09; P = 0.02).

Conclusions

In our study in an ICU, appropriateness of the empirical antibiotic therapy and the overall survival were associated with a greater decline in PCT between D2 and D3. Further studies are needed to assess the utility of the daily monitoring of PCT in addition to clinical evaluation during the early management of sepsis.

Salivary procalcitonin and periodontitis in diabetes

Periodontitis and type 2 diabetes are co-morbid conditions, both characterized by infectious susceptibility. We investigated procalcitonin (ProCT) levels in the serum and saliva of persons with periodontitis and type 2 diabetes (n = 20), to determine if these levels are altered by periodontitis activity or by hyperglycemia. Persons with severe periodontitis showed higher levels of salivary-ProCT than did those with moderate periodontitis (241 +/- 71 vs. 77 +/- 516 pg/mL, p = 0.02) and higher levels than did healthy control individuals (118 +/- 26 pg/mL, p = 0.05). Salivary-ProCT levels were correlated with bleeding-on-probing (r = 0.45, p = 0.05), as well as with HgbA(1c) (r = 0.49, p = 0.03). Salivary levels of ProCT were higher than serum levels for the periodontitis/diabetes group (152 +/- 37 vs. 78 +/- 17 pg/mL, p = 0.02) and the control group (118 +/- 146 vs. 48 +/- 17 pg/mL, p = 0.01). Persons with periodontitis and type 2 diabetes have salivary-ProCT levels that reflect their degree of periodontitis activity and hyperglycemia. This study demonstrates, for the first time, the presence of procalcitonin (ProCT), an established serum marker of infection, in saliva.

Procalcitonin in liver transplantation: are high levels due to donors or recipients?

Introduction

To date, a specific marker to evaluate and predict the clinical course or complication of the liver-transplanted patient is not available in clinical practice. Increased procalcitonin (PCT) levels have been found in infectious inflammation; poor organ perfusion and high PCT levels in the cardiac donor appeared to predict early graft failure. We evaluated PCT as a predictor of early graft dysfunction and postoperative complications.

Methods

PCT serum concentrations were measured in samples collected before organ retrieval from 67 consecutive brain-dead donors and in corresponding recipients from day 0, before liver transplantation, up to day 7 after liver transplantation. The following parameters were recorded in donors: amount of vasopressive drug doses, cardiac arrest history 24 hours before retrieval, number of days in the intensive care unit, age of donor, and infection in donor, and the following parameters were recorded in recipients: cold and warm ischemia time, veno-venous bypass, transfusion amount during orthotopic liver transplantation (OLT), and occurrence of postoperative complication or hepatic dysfunction.

Results

In the donor, the preoperative level of PCT was associated with cardiac arrest and high doses of catecholamines before organ retrieval. In the recipient, elevated PCT levels were observed early after OLT, with a peak at day 1 or 2 after OLT, then a decrease until day 7. A postoperative peak of PCT levels was associated neither with preoperative PCT levels in the donor or the recipients nor with hepatic post-OLT dysfunction or other postoperative complications, but with two donor parameters: infection and cardiac arrest.

Conclusion

PCT level in the donor and early PCT peak in the recipient are not predictive of post-OLT hepatic dysfunction or other complications. Cardiac arrest and infection in the donor, but not PCT level in the donor, are associated with high post-OLT PCT levels in the recipient.

Usefulness of procalcitonin serum level for the discrimination of severe sepsis from sepsis: a multicenter prospective study

Procalcitonin serum level has been recommended as a new marker of bacterial infectious diseases. The aim of this prospective, multicenter study was to determine the clinical usefulness of procalcitonin in differentiating patients with sepsis from those with severe sepsis. Eighty-two patients were enrolled: 20 without systemic inflammatory response syndrome (SIRS), 9 with SIRS, 34 with sepsis, and 19 with severe sepsis. The patients with severe sepsis had significantly higher procalcitonin levels (median, 36.1 ng/ml) than those with sepsis (median, 0.6 ng/ml). With a procalcitonin cutoff value of 2.0 ng/ml, sensitivity for the detection of severe sepsis and specificity for the detection of sepsis were 94.7% and 78.1%, respectively. A good correlation was found between the serum procalcitonin level and the Sepsis-Related Organ Failure Assessment (SOFA) score (r = 0.680), although no correlation was found between the C-reactive protein (CRP) level and the SOFA score. In conclusion, the procalcitonin serum level may be useful not only for aiding the diagnosis of sepsis but also for discriminating between sepsis and severe sepsis.