The plasma elimination rate and urinary secretion of procalcitonin in patients with normal and impaired renal function

The association between procalcitonin and acute kidney injury in patients stung by wasps

Introduction: The aim of this study was to investigate the status of serum procalcitonin (PCT) in patients stung by wasps and evaluate the association between PCT levels and acute kidney injury (AKI). Methods: Patients stung by wasps admitted to two tertiary hospitals between January 2017 and December 2020 were screened for enrollment. We evaluated serum PCT levels on admission in patients stung by wasps. The patients were divided into an AKI group and a non-AKI group. A logistic regression model was used to analyze the association between PCT status and AKI. The performance of PCT concentrations in predicting the occurrence of AKI was evaluated by the area under the receiver operating characteristic curve (AUROC). Results: A total of 138 patients were enrolled, and 66 patients suffered AKI. PCT levels were elevated in 78.99% of patients stung by wasps. Nearly half of the patients (47.83%) developed AKI. PCT levels were correlated with creatinine levels on admission (r = 0.787, 95% CI: 0.713-0.844). PCT levels in patients with AKI were higher than those in patients without AKI (p < 0.001). After adjustment for covariates, PCT levels on admission were independently associated with AKI (OR: 1.575, 95% CI: 1.071-2.317, p = 0.021). The AUROC of PCT levels on admission was 0.837 (95% CI, 0.771-0.902, p < 0.001). A PCT level of 0.57 μg/L was the cutoff for maximizing the Youden index; the specificity was 79.45%, and the sensitivity was 73.43%. Conclusion: Serum PCT levels may be a potential biomarker of AKI in patients stung by wasps.

Case report: Ewing sarcoma with EWSR-ERG fusion elevates procalcitonin extremely in the long term without infection

Background

Ewing sarcoma (ES) represents a rare, aggressive bone and soft-tissue cancer. Unlike breast, liver, pancreatic, and prostate cancers, Ewing sarcoma has had no representative tumor marker until now. The use of procalcitonin (PCT) as a tumor marker is also rarely reported. PCT is a clinically recognized and widely used inflammatory marker in recent years. In rare cases, PCT may also be falsely positive due to non-infectious factors. In the few previously reported papers regarding the correlation between tumors and PCT, we learned that abnormalities of PCT level can also be impacted by individual cancers.

Case presentation

Here, we first reported a case of Ewing sarcoma with markedly elevated PCT without infection and carried out some literature review. The patient was a middle-aged man with extraskeletal Ewing sarcoma whose lesion was located in the distal abdominal ileum. He had a sudden and unprovoked onset of high fever during chemotherapy before surgery. After multiple examinations, the patient's blood routine, C-reactive protein, blood culture, and CT examination showed no signs of infection, and even the culture from the end of the central venous catheter showed no pathogen growth. Only PCT increased dramatically to more than 200 ng/ml. PCT remained at this level for several months until a single abdominal lumpectomy was performed before it dropped to near-normal levels.

Conclusion

In our report, PCT is significantly elevated in Ewing sarcoma in the absence of infection. Not only that, but we particularly highlighted the precipitous drop in PCT following tumor resection.

The Sustained and Marked Elevation of Serum Procalcitonin in a Hemodialysis Patient with Tuberculous Lymphadenitis, but Without the Evidence of Sepsis: A Case Report

Background

The elevation of serum procalcitonin (PCT) has been considered as a marker of systemic bacterial infection and sepsis. However, the marked elevation of PCT in non-sepsis conditions was rare. Here, we report a rare case of sustained markedly elevation of serum PCT in a dialysis patient with tuberculosis, but without the evidence of sepsis.

Case Presentation

A 25-year-old man on maintenance hemodialysis was admitted to the hospital for kidney transplantation. On admission, physical examination revealed multiple lymph nodes were palpable on both sides of the neck which was later confirmed as tuberculosis with biopsy pathology. On the 3rd day after admission, the patient suffered from fever with a temperature of 38.8°C. The white blood cells 12.35 × 10⁹/L and the PCT level was 5.73 ng/mL. Lately the PCT increased to 63.10 ng/mL, and the level of C-reactive protein was 186.00 mg/L. After the antibiotics upgraded from cefmetazole to meropenem, and vancomycin was added, the body temperature dropped to the normal range on the 17th day and remained normal thereafter. The PCT level declined gradually to 4.18 ng/mL on the 21st day and an antituberculosis regimen was started. After that, the PCT levels fluctuated between 2.9 ng/mL and 94.9 ng/mL without any manifestation of sepsis. The markedly elevation of serum PCT level persisted despite normal C-reactive protein level and leukocyte counts.

Conclusion

Persistently elevated serum PCT level might occur in conditions without evidence of sepsis. Taking consideration of multiple inflammatory factors to determine infection when the markedly elevated PCT level was not correlated with the clinical manifestations.

Kinetic changes in serum procalcitonin predict persistent acute kidney injury in critical patients

PURPOSE

Persistent acute kidney injury (AKI) has been shown to be closely associated with poor prognosis in critical patients. Recent studies have shown that procalcitonin (PCT) is valuable for the early prediction of AKI in critically patients. Our aim was to determine whether PCT and its kinetic changes could predict the occurrence of persistent AKI in critical patients.

METHODS

This is a prospective observational study. The definition of AKI was based on the Kidney Disease: Improving Global Outcomes criteria. Persistent AKI was defined as renal function that does not return to baseline serum creatinine levels within 48 h. Blood samples were obtained at the onset of AKI and two subsequent days of hospital stay. 24-h PCT change (ΔPCT-24 h) was defined as 24 h PCT minus baseline PCT (day 0).

RESULTS

A total of 91 critical patients with AKI were included in this study. The persistent AKI group had a stepwise increase in PCT concentration. ΔPCT-24 h was higher in the persistent AKI group (p < .01). Logistic regression analysis showed that ΔPCT-24 h (p = .04) was independent predictors of persistent AKI. The receiver operating characteristic curves showed that area under the curve of ΔPCT-24 h was 0.84 (p < .01), and the cut-off value for PCT to predict persistent AKI was 0.56 ng/ml.

CONCLUSION

Our study showed that the observation of kinetic changes in PCT is more significant for the early prediction of persistent AKI than the index of PCT at a single time point. ΔPCT-24 h is a good predictor of persistent AKI in critical patients.

Procalcitonin serum levels in stage 5 chronic kidney disease children on hemodialysis

BACKGROUND

Infections are responsible for morbidity and mortality in children on hemodialysis (HD). Procalcitonin (PCT) is rarely used in this population, even though it is an efficient biomarker of infection and sepsis. Our aim was to study PCT baseline level in uninfected children with stage 5 chronic kidney disease (CKD 5) on HD, and determine how to use it in this population.

METHODS

Prospective observational study including 40 uninfected children on classical HD or hemodiafiltration (HDF) in three pediatric HD centers in the Paris region. PCT was monitored before and after three consecutive sessions within 1 week.

RESULTS

Median pre-dialysis PCT was 0.60 ng/mL [0.36-1.15], median post-dialysis PCT was 0.23 ng/mL [0.10-0.47], PCT reduction rate was 59.8% [37.5-75.8]. Seventy percent of pre-dialysis PCT were <1 ng/mL. Anuric patients had higher pre-dialysis PCT than those with residual urine output (0.70 [0.42-1.30] vs. 0.48 [0.30-0.93] ng/mL, p=0.01). HDF was more efficient than HD to clear PCT during sessions (reduction rate 75% [67-80] vs. 37 [31-50]), p<0.001).

CONCLUSION

PCT levels in pediatric HD patients without infection are higher than normal, but this increase is relatively moderate compared to massive increases of PCT in children with bacterial infections on HD. If PCT is measured after dialysis sessions, the specific technique-dependent reduction rates should be taken into consideration. Moderately increased PCT levels around 2 ng/ml should be interpreted with caution; however, higher PCT serum levels can be used to motivate rapid start of antibiotic treatment in pediatric HD patients.

A Remarkable Elevation in the Procalcitonin Levels Due to Diabetic Ketoacidosis in a Hemodialysis Patient

Procalcitonin (PCT), a marker of the inflammatory response during infections, can be elevated by diabetic ketoacidosis (DKA). A male patient in his 50s with diabetic nephropathy on hemodialysis presented with vomiting and a reduced level of consciousness and was diagnosed with DKA. His PCT level was markedly elevated, but bacterial cultures (blood, urine, and stool) were negative. The PCT level decreased after DKA improvement. In this patient, DKA probably enhanced the PCT levels. As DKA can increase the PCT levels, an elevation of the PCT levels in DKA patients may not be indicative of infectious diseases, and non-infectious causes of DKA should therefore be considered.

The Relationship between Serum Procalcitonin and Dialysis Adequacy in Peritoneal Dialysis Patients

Background:

To detect the serum procalcitonin (PCT) levels of peritoneal dialysis (PD) patients.

Methods:

We analyzed the relationship between the PCT Level and dialysis adequacy. We studied 120 peritoneal dialysis patients without signs of infection in Affiliated Hangzhou First People’s Hospital and 120 controls from Jan 2014 to Apr 2016. PCT and high sensitivity C-reactive protein (hs-CRP) were detected. 120 PD patients were divided into two groups according to the dialysis adequacy. A correlation analysis was processed between the PCT level and the total solute clearance (Kt/V). The value of PCT for identifying the dialysis adequacy in PD patients was assessed by ROC curve analysis.

Results:

PCT level in serum of PD group (0.29±0.24 ng/ml) was higher than that of the control group (0.02±0.01 ng/ml) (P<0.01). Compared with the inadequate dialysis group (0.5±0.37 ng/ml), the PCT Level of the adequate dialysis group (0.23±0.15 ng/ml) was lower (P<0.01). There were negative correlations between PCT and Kt/v(r=−0.451), Prealbumin (PA) (r=−0.258), Glomerular Filtration Rate (eGFR; r=−0.280), while there was positive correlation between PCT and Hypersensitive c-reactive protein (r=0.458) (P<0.01). At a serum PCT cut-off value of 0.283 ng/ml, the sensitivity and specificity for identifying the dialysis adequacy in PD patients were 0.913 and 0.805 respectively. The serum levels of PCT in peritoneal dialysis patients were significantly higher than the levels in healthy controls.

Conclusion:

The serum level of PCT can be used as an indirect maker to evaluate the adequacy of dialysis.

Utility of Procalcitonin as a Biomarker for Sepsis in Children

Sepsis is a complex process defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. It is associated with significant morbidity and mortality rates in both adults and children, and emphasis has been placed on its early recognition and prompt provision of antimicrobials. Owing to limitations of current diagnostic tests (i.e., poor sensitivity and delayed results), significant research has been conducted to identify sepsis biomarkers. Ideally, a biomarker could reliably and rapidly distinguish bacterial infection from other, noninfectious causes of systemic inflammatory illness. In doing so, a sepsis biomarker could be used for earlier identification of sepsis, risk stratification/prognostication, and/or guidance of antibiotic decision-making. In this minireview, we review one of the most common clinically used sepsis biomarkers, procalcitonin, and its roles in sepsis management in these three areas. We highlight key findings in the adult literature but focus the bulk of this review on pediatric sepsis. The challenges and limitations of procalcitonin measurement in sepsis are also discussed.

Independent Predictive Ability of Procalcitonin of Acute Kidney Injury among Critically Ill Patients

It is unclear whether serum procalcitonin (PCT) levels rise in patients with acute kidney injury (AKI), and it is also unclear whether the elevation of PCT levels in this setting is independent of the existence of infection and impaired renal clearance. We conducted a retrospective study in a regional teaching hospital in Taiwan to evaluate the AKI-predictive ability of serum PCT among critically ill patients. We enrolled 330 patients (mean age, 70.5 ± 16.4 years; 57.0% men) who were admitted to the intensive care unit (ICU) from 1 July 2016, to 31 December 2016, and who had serum PCT measurement performed within 24 h after ICU admission. We used the generalized additive model and generalized linear model to evaluate the association of serum PCT levels and renal function variables. In addition, we used the multivariate logistic regression method to demonstrate serum PCT level as an independent predictor of AKI in both the non-infected patients (odds ratio (OR) = 1.38, 95% confidence interval (CI) = 1.12–1.71, p = 0.003) and the infected patients (OR = 1.23, 95% CI = 1.03–1.46, p = 0.020). In conclusion, serum PCT level at ICU admission is an independent predictor of developing AKI irrespective of infection among critically ill patients.

COVID-19 Pneumonia in a Hemodialysis Patient

Coronavirus disease 2019 (COVID-19) is a highly infective disease caused by the severe acute respiratory syndrome coronavirus 2 virus (SARS-CoV-2). Previous studies of the COVID-19 pneumonia outbreak were based on information from the general population. Limited data are available for hemodialysis patients with COVID-19 pneumonia. This report describes the clinical characteristics of COVID-19 in an in-center hemodialysis patient, as well as our experience in implementing steps to prevent the spread of COVID-19 pneumonia among in-center hemodialysis patients. The diagnosis, infection control, and treatment of COVID-19 in hemodialysis patients are discussed in this report, and we conclude with recommendations for how a dialysis facility can respond to COVID-19 based on our experiences.

Procalcitonin: A promising tool or just another overhyped test?

Sepsis is the leading cause of death worldwide. Timely administration of antibiotics is recognized as the cornerstone in the management of sepsis. However, inappropriate use of antibiotics may lead to adverse effects and the selection of drug-resistant pathogens. Microbiological cultures remain the gold standard to diagnose infection despite their low sensitivity and the intrinsic delay to obtain the results. Certain biomarkers have the benefit of rapid turnover, potentially providing an advantage in timely diagnosis leading to accurate treatment. Over the last few decades, there is an ongoing quest for the ideal biomarker in sepsis. Procalcitonin (PCT), when used alone or alongside additional clinical information, has shown to be a promising tool to aid in the diagnosis and management of patients with sepsis. In February 2017, the Food and Drug Administration (FDA) approved the use of PCT to guide antibiotic treatment in lower respiratory tract infections and sepsis. Despite a good negative predictive value for bacterial infection, the utility of PCT-guided antibiotic initiation is conflicting at best. On the other hand, the use of PCT-guided antibiotic discontinuation has shown to reduce the duration of antibiotic use, the associated adverse effects, and to decrease the overall mortality. The current review discusses the history and pathophysiology of procalcitonin, synthesizes its utility in the diagnosis and management of sepsis, highlights its limitations and compares it with other biomarkers in sepsis.

Evaluation of INSTAND e.V.'s external quality assessment for C-reactive protein and procalcitonin

Background

The purpose of this paper was to analyze the general diagnostic strength and performance of in vitro diagnostics for C-reactive protein and procalcitonin based on the results of external quality assessment schemes (EQAs).

Methods

We analyzed qualitative and quantitative data on both markers collected by the Society for Promotion Quality Assurance in Medical Laboratories (INSTAND e.V.) from 20 EQAs. The C-reactive protein evaluation was method-specific and the procalcitonin evaluation manufacturer-specific (pseudonymized). Coefficients of variation were determined in order to evaluate interlaboratory comparability and the performance of individual laboratories during the analyzed period was examined.

Results

Overall most of our participants were able to correctly distinguish the positive from the negative samples, but we occasionally observed also false-positive results for the immunological detection of C-reactive protein. For the semi-quantitative results of C-reactive protein we observed an overall median difference below 5% except for dry chemistry methods (≤ 21%). For procalcitonin two manufacturer collectives showed a good comparability, while one manufacturer detected up to 42% higher results. The coefficients of variation are promising for both analytes even though they surpass the manufacturer’s indication for some collectives. The performance of individual laboratories during the analyzed period was more stable for C-reactive protein than for procalcitonin.

Conclusion

In-vitro diagnostic testing for C-reactive protein and procalcitonin showed promising results in our EQAs but still further improvements are needed. We recommend stepping up research on reference measurement methods for both parameters to possibly enhancing the accuracy and diagnostic strength of such assays.

Value of serum procalcitonin for the diagnosis of bacterial septic arthritis in daily practice in rheumatology

INTRODUCTION/OBJECTIVES

Septic arthritis is a diagnostic and therapeutic emergency because of a high morbidity and mortality. Nevertheless, the etiologic diagnosis is often difficult. The aim of our study was to determine if serum procalcitonin was a discriminatory biomarker in case of arthritis of undetermined etiology.

METHOD

Patients were separated in five groups: gouty arthritis, calcium pyrophosphate deposition arthritis, osteoarthritis or post-traumatic arthritis ("mechanical" arthritis), chronic inflammatory rheumatic arthritis, and septic arthritis. Levels of serum white blood cells, C-reactive protein and procalcitonin were measured.

RESULTS

Ninety-eight patients were included: 18 in the "gout" group, 26 in the "calcium pyrophosphate deposition arthritis" group, 16 in the mechanical group, 18 in the "chronic inflammatory rheumatic" group, and 20 in the "sepsis" group. The area under the receiver operating characteristic curve of white blood cells, C-reactive protein, and procalcitonin levels to diagnose a septic arthritis were 0.69 (IC95% 0.55-0.83), 0.82 (IC95% 0.73-0.91), and 0.87 (IC95% 0.76-0.98) respectively. For a cutoff of 0.5 ng/ml, procalcitonin sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio and negative likelihood ratio were 65%, 91%, 65%, 91%, 7.2, and 0.4, respectively. Serum C-reactive protein and procalcitonin levels were correlated, were not different in sepsis or gout groups, and were higher in non-septic arthritis with poly-arthritis than with mono-arthritis (p < 0.05).

CONCLUSIONS

Serum procalcitonin is a useful biomarker in arthritis management with diagnosis performances higher than those of other biomarkers (white blood cells, C-reactive protein).Key Points• Diagnostic performances of serum procalcitonin level in septic arthritis are higher than those of serum C-reactive protein or white blood cells levels.• Serum procalcitonin levels are not different in septic arthritis or gouty arthritis.• Serum procalcitonin levels are higher in non-septic arthritis with poly-arthritis than with mono-arthritis.

Symmetrical (SDMA) and asymmetrical dimethylarginine (ADMA) in sepsis: high plasma levels as combined risk markers for sepsis survival

BACKGROUND

Nitric oxide (NO) regulates processes involved in sepsis progression, including vascular and immune function. NO is generated by nitric oxide synthases (NOS) from L-arginine. Cellular L-arginine uptake is inhibited by symmetric dimethylarginine (SDMA) and asymmetric dimethylarginine (ADMA) is a competitive inhibitor of NOS. Increased inhibitor blood concentrations lead to reduce NO bioavailability. The aim of this study was to determine whether plasma concentrations of SDMA and ADMA are markers for sepsis survival.

METHOD

This prospective, single center study involved 120 ICU patients with sepsis. Plasma SDMA and ADMA were measured on admission (day 1), day 3 and day 7 by mass spectrometry together with other laboratory markers. The sequential organ failure assessment (SOFA) score was used to evaluate sepsis severity. Survival was documented until day 28. Groups were compared using the Mann-Whitney U test, chi-squared test or non-parametric analysis of variance (ANOVA). Mortality was assessed using Kaplan-Meier curves and compared using the log-rank test. Specific risk groups were identified using a decision tree algorithm.

RESULTS

Median plasma SDMA and ADMA levels were significantly higher in non-survivors than in survivors of sepsis: SDMA 1.14 vs. 0.82 μmol/L (P = 0.002) and ADMA 0.93 vs. 0.73 μmol/L (P = 0.016). ANOVA showed that increased plasma SDMA and ADMA concentrations were significantly associated with SOFA scores. The 28-day mortality was compared by chi-square test: for SDMA the mortality was 12% in the lower, 25% in the intermediate and 43% in the 75th percentile (P = 0.018); for ADMA the mortality was 18-20% in the lower and intermediate but 48% in the 75th percentile (P = 0.006). The highest mortality (61%) was found in patients with plasma SDMA > 1.34 together with ADMA levels > 0.97 μmol/L.

CONCLUSIONS

Increased plasma concentrations of SDMA and ADMA are associated with sepsis severity. Therefore, our findings suggest reduced NO bioavailability in non-survivors of sepsis. One may use individual SDMA and ADMA levels to identify patients at risk. In view of the pathophysiological role of NO we conclude that the vascular system and immune response are most severely affected when SDMA and ADMA levels are high.

Biological variation of procalcitonin levels in hemodialysis patients

BACKGROUND

There is no obvious evidence regarding biological variation of procalcitonin (PCT) levels in hemodialysis (HD) patients without infections. The aim of this study was to determine the within- and between-person biological variation of PCT levels in HD patients without infections.

METHODS

A multicenter, prospective, cohort study enrolled 123 HD patients without any signs of infectious disease. Baseline PCT levels were determined pre- and post-HD, and then repeated pre-HD PCT measurements were performed at 2, 4, 8, 12, 16, 20, and 24 weeks after baseline blood-sampling, regardless of the presence or absence of infectious disease. Analytical variation (CVa), the within-person biological variation (CVi), between-person biological variation (CVb), individual index (II), and the reference change value (RCV) were calculated.

RESULTS

The mean age was 62.4 years, 76.4% were male, and 32.5% had diabetes. The mean duration of HD was 87 months. The median value for baseline pre-HD PCT was 0.23 ng/mL, which is much higher than the reference level for healthy individuals. PCT levels decreased of 46.6% after a single HD session. CVi was 24.9%, CVb was 54.2%, II was 0.46, and RCV was calculated as 96.4% with 99% probability.

CONCLUSIONS

The PCT level was significantly higher in stable HD patients without manifest bacterial infection. CVb was more variable than CVi in HD patients, which indicates that relative change is more important than absolute PCT levels for diagnosing bacterial infection, and doubling or more of the baseline PCT level may imply the presence of a bacterial infection in HD patients.

Clinical value of procalcitonin for suspected nosocomial bloodstream infection

BACKGROUND/AIMS

Procalcitonin (PCT) may prove to be a useful marker to exclude or predict bloodstream infection (BSI). However, the ability of PCT levels to differentiate BSI from non-BSI episodes has not been evaluated in nosocomial BSI.

METHODS

We retrospectively reviewed the medical records of patients ≥ 18 years of age with suspected BSI that developed more than 48 hours after admission.

RESULTS

Of the 785 included patients, 105 (13.4%) had BSI episodes and 680 (86.6%) had non-BSI episodes. The median serum PCT level was elevated in patients with BSI as compared with those without BSI (0.65 ng/mL vs. 0.22 ng/mL, p = 0.001). The optimal PCT cut-off value of BSI was 0.27 ng/mL, with a corresponding sensitivity of 74.6% (95% confidence interval [CI], 66.4% to 81.7%) and a specificity of 56.5% (95% CI, 52.7% to 60.2%). The area under curve of PCT (0.692) was significantly larger than that of C-reactive protein (CRP; 0.526) or white blood cell (WBC) count (0.518). However, at the optimal cut-off value, PCT failed to predict BSI in 28 of 105 cases (26.7%). The PCT level was significantly higher in patients with an eGFR < 60 mL/min/1.73 m² than in those with an eGFR ≥ 60 mL/min/1.73 m² (0.68 vs. 0.17, p = 0.01).

CONCLUSIONS

PCT was more useful for predicting nosocomial BSI than CRP or WBC count. However, the diagnostic accuracy of predicting BSI remains inadequate. Thus, PCT is not recommended as a single diagnostic tool to avoid taking blood cultures in the nosocomial setting.

The role of serum procalcitonin in establishing the diagnosis and prognosis of pleural infection

Background

Bacterial pleural infection requires prompt identification to enable appropriate investigation and treatment. In contrast to commonly used biomarkers such as C-reactive protein (CRP) and white cell count (WCC), which can be raised due to non-infective inflammatory processes, procalcitonin (PCT) has been proposed as a specific biomarker of bacterial infection. The utility of PCT in this role is yet to be validated in a large prospective trial. This study aimed to identify whether serum PCT is superior to CRP and WCC in establishing the diagnosis of bacterial pleural infection.

Methods

Consecutive patients presenting to a tertiary pleural service between 2008 and 2013 were recruited to a well-established pleural disease study. Consent was obtained to store pleural fluid and relevant clinical information. Serum CRP, WCC and PCT were measured. A diagnosis was agreed upon by two independent consultants after a minimum of 12 months. The study was performed and reported according to the STARD reporting guidelines.

Results

80/425 patients enrolled in the trial had a unilateral pleural effusion secondary to infection. 10/80 (12.5%) patients had positive pleural fluid microbiology. Investigations for viral causes of effusion were not performed. ROC curve analysis of 425 adult patients with unilateral undiagnosed pleural effusions showed no statistically significant difference in the diagnostic utility of PCT (AUC 0.77), WCC (AUC 0.77) or CRP (AUC 0.85) for the identification of bacterial pleural infection. Serum procalcitonin >0.085 μg/l has a sensitivity, specificity, negative predictive value and positive predictive value of 0.69, 0.80, 0.46 and 0.91 respectively for the identification of pleural infection. The diagnostic utility of procalcitonin was not affected by prior antibiotic use (p = 0.80).

Conclusions

The study presents evidence that serum procalcitonin is not superior to CRP and WCC for the diagnosis of bacterial pleural infection. The study suggests routine procalcitonin testing in all patients with unilateral pleural effusion is not beneficial however further investigation may identify specific patient subsets that may benefit.

Trial registration

The trial was registered with the UK Clinical Research Network (UKCRN ID 8960). The trial was approved by the South West Regional Ethics Committee (Ethical approval number 08/H0102/11).

Electronic supplementary material

The online version of this article (doi:10.1186/s12931-017-0501-5) contains supplementary material, which is available to authorized users.

Serum Level of HMGB1 Protein and Inflammatory Markers in Patients with Secondary Peritonitis: Time Course and the Association with Clinical Status

Background

Intra-abdominal infection in secondary peritonitis drives as excessive production of inflammatory mediators and the development of systemic inflammatory response syndrome (SIRS) or sepsis. Finding a specific marker to distinguish SIRS from sepsis would be of immense clinical importance for the therapeutic approach. It is assumed that high-mobility group box 1 protein (HMGB1) could be such a marker. In this study, we examined the time course changes in the blood levels of HMGB1, C-reactive protein (CRP), procalcitonin (PCT) and serum amyloid A (SAA) in patients with secondary peritonitis who developed SIRS or sepsis.

Methods

In our study, we evaluated 100 patients with diffuse secondary peritonitis who developed SIRS or sepsis (SIRS and SEPSIS group) and 30 patients with inguinal hernia as a control group. Serum levels of HMGB1, CRP, PCT, and SAA were determined on admission in all the patients, and monitored daily in patients with peritonitis until discharge from hospital.

Results

Preoperative HMGB1, CRP, PCT and SAA levels were statistically highly significantly increased in patients with peritonitis compared to patients with inguinal hernia, and significantly higher in patients with sepsis compared to those with SIRS. All four inflammatory markers changed significantly during the follow-up. It is interesting that the patterns of change of HMGB1 and SAA over time were distinctive for SIRS and SEPSIS groups.

Conclusions

HMGB1 and SAA temporal patterns might be useful in distinguishing sepsis from noninfectious SIRS in secondary peritonitis.

Impact of hepatic function on serum procalcitonin for the diagnosis of bacterial infections in patients with chronic liver disease: A retrospective analysis of 324 cases

Although procalcitonin (PCT) is a valid marker for early diagnosis of bacterial infections, it is unclear whether its accuracy in predicting bacterial infections is affected by impaired liver function. This study aimed to assess the impact of compromised liver function on the diagnostic value of PCT.This retrospective study was conducted between January 2013 and May 2015. A total of 324 patients with chronic liver disease were enrolled. Routine laboratory measurements and PCT were performed. Patients were divided into 3 groups according to clinical diagnosis: chronic hepatitis (group 1), decompensated cirrhosis (group 2), and acute-on-chronic liver failure/chronic liver failure (group 3). The correlation between PCT and liver function was analyzed. The area under the receiver operating characteristic (AUCROC) curve of PCT was analyzed according to infection status and liver function.PCT was more accurate than white blood cell count (P < 0.001) and percentage of neutrophils (P < 0.001) in detecting bacterial infections in patients with impaired liver function. In patients without infection, PCT had a moderate positive correlation with serum total bilirubin (TBIL) (r = 0.592), and a weak correlation with model for end-stage liver disease score (r = 0.483) and international normalized ratio (r = 0.389). The AUCROC and optimum thresholds of PCT and for predicting bacterial infections at different levels of TBIL were 0.907 (95% CI 0.828-0.958) and 0.38 ng/mL, respectively, for TBIL <5 mg/dL, 0.927 (95% CI 0.844-0.974) and 0.54 ng/mL (5 mg/dL ≤TBIL<10 mg/dL), 0.914 (95% CI 0.820-0.968) and 0.61 ng/mL (10 mg/dL ≤TBIL<20 mg/dL), 0.906 (95% CI 0.826-0.958) and 0.94 ng/mL (TBIL ≥20 mg/dL), respectively.This study demonstrated that PCT was a valuable marker of bacterial infection in patients with chronic liver diseases. TBIL affected PCT threshold, so different cut-offs should be used according to different TBIL values.

Usefulness of serum procalcitonin as a diagnostic biomarker of infection in children with chronic kidney disease

INTRODUCTION

Serum procalcitonin (PCT) levels are known to be low in healthy individuals in healthy subjects but are increased in patients with a severe bacterial infection. It has not been extensively studied in children with chronic kidney disease (CKD), treated either with hemodialysis (HD) or with renal transplantation.

MATERIAL AND METHODS

During a 6-month period, blood samples were taken from 102 (55 HD children and 47 renal transplant recipients) children with a strong clinical suspicion of infection. Procalcitonin levels were measured by ELISA.

RESULTS

Thirty-four/102 cases had proven infections as defined previously. Children with proven infections had a significantly higher PCT (0.920 ±0.24 ng/ml) than those without (0.456 ±0.53 ng/ml), p = 0.04. The ideal cutoff value derived for serum PCT was 0.5 ng/ml. This threshold value established a sensitivity of 94.1% and a specificity of 87.9%.

CONCLUSIONS

This study indicates that significantly increased PCT concentration is a promising predictor of systemic bacterial infection in children with CKD, with good sensitivity and specificity. This study proposes that serum PCT is a convenient index of infection in CKD children at a cutoff value of 0.5 ng/ml.

High Level Serum Procalcitonin Associated Gouty Arthritis Susceptibility: From a Southern Chinese Han Population

Objectives

To study the serum Procalcitonin (PCT) level in inflammatory arthritis including gouty arthritis (GA), Rheumatoid arthritis (RA), and ankylosing spondylitis (AS) without any evidence of infection were evaluated the possible discriminative role of PCT in gouty arthritis susceptibility in southern Chinese Han Population.

Material and Methods

From Feb, 2012 to Feb, 2015, 51 patients with GA, 37 patients with RA, 41 patients with AS and 33 healthy control were enrolled in this study with no evidence of infections. The serum level of PCT (normal range < 0.05 ng/ml) was measured by electrochemiluminescence immunoassay (ECLIA). Disease activity was determined by scores of VAS (4.07 ± 1.15), DAS28 (4.97 ± 1.12), and ASDAS (2.97 ± 0.81) in GA, RA and AS groups respectively. Other laboratory parameters such as, serum creatinine (CRE), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), uric acid (UA) and white blood cells (WBC) were extracted from medical record system.

Results

Serum PCT level was predominantly higher in gouty arthritis than in RA and AS patients, especially in the GA patients with tophi. PCT was significantly positively correlated with VAS, CRP and ESR in gouty arthritis and CRP in AS. PCT also had positive correlation-ship with ESR, DAS28 and ASDAS in RA and AS patients respectively, but significant differences were not observed.

Conclusions

These data suggested that PCT is not solely a biomarker for infection, but also an indicator in inflammatory arthritis, especially in gouty arthritis.

Sepsis: From Pathophysiology to Individualized Patient Care

Sepsis has become a major health economic issue, with more patients dying in hospitals due to sepsis related complications compared to breast and colorectal cancer together. Despite extensive research in order to improve outcome in sepsis over the last few decades, results of large multicenter studies were by-and-large very disappointing. This fiasco can be explained by several factors, but one of the most important reasons is the uncertain definition of sepsis resulting in very heterogeneous patient populations, and the lack of understanding of pathophysiology, which is mainly based on the imbalance in the host-immune response. However, this heroic research work has not been in vain. Putting the results of positive and negative studies into context, we can now approach sepsis in a different concept, which may lead us to new perspectives in diagnostics and treatment. While decision making based on conventional sepsis definitions can inevitably lead to false judgment due to the heterogeneity of patients, new concepts based on currently gained knowledge in immunology may help to tailor assessment and treatment of these patients to their actual needs. Summarizing where we stand at present and what the future may hold are the purpose of this review.

Potential use of procalcitonin as biomarker for bacterial sepsis in patients with or without acute kidney injury

INTRODUCTION

There are few investigations regarding the relationships between procalcitonin (PCT) and the acute kidney injury (AKI) in the diagnosis of sepsis. The purpose of this study was to clarify the diagnostic accuracy of the use of PCT levels in patients with or without AKI.

METHODS

This study was conducted as a single-center retrospective study. We enrolled 393 patients in whom PCT were measured on admission. We grouped the patients into non-AKI and AKI, and those with AKI were classified according to the RIFLE criteria (Risk, Injury, Failure). The patients in each group were further classified into the sepsis and the non-sepsis group. We subsequently investigated the diagnostic accuracy of the PCT for detecting sepsis in these groups.

RESULTS

The levels of PCT were significantly higher in the sepsis group than in the non-sepsis group among the non-AKI and each AKI patients (p < 0.0001). The diagnostic accuracy of the PCT for detecting sepsis was determined according to a ROC analysis; AUC value was 0.958 in the non-AKI group, in the Risk, Injury and Failure groups were 0.888 and 0.917, 0.857, respectively. AUC value for non-AKI group was significantly different from that of Failure group (p < 0.05).

CONCLUSIONS

In Failure AKI patients, the diagnostic accuracy of the PCT level is significantly lower than non-AKI patients. It is therefore suggested that we should be careful in using PCT value to diagnose sepsis in patients with Failure under RIFLE criteria.

Pre-analytic factors and initial biomarker levels in community-acquired pneumonia patients

BACKGROUND

Blood biomarkers are increasingly used to diagnose, guide therapy in, and risk-stratify community-acquired pneumonia (CAP) patients in emergency departments (EDs). How pre-analytic factors affect these markers' initial levels in this population is unknown.

METHODS

In this secondary analysis of consecutive ED patients with CAP from a large multicentre antibiotic stewardship trial, we used adjusted multivariate regression models to determine the magnitude and statistical significance of differences in mean baseline concentrations of five biomarkers (procalcitonin [PCT], C-reactive protein [CRP], white blood cells count [WBC], proadrenomedullin [ProADM], copeptin) associated with six pre-analytic factors (antibiotic or corticosteroid pretreatment, age, gender, chronic renal failure or chronic liver insufficiency).

RESULTS

Of 925 CAP patients (median age 73 years, 58.8% male), 25.5% had antibiotic pretreatment, 2.4%, corticosteroid pretreatment, 22.3%, chronic renal failure, 2.4% chronic liver insufficiency. Differences associated with pre-analytic factors averaged 6.1% ± 4.6%; the three largest statistically significant changes (95% confidence interval) were: PCT, +14.2% (+2.1% to +26.4%, p = 0.02) with liver insufficiency; ProADM, +13.2% (+10.2% to +16.1%, p < 0.01) with age above median; CRP, -12.8% (-25.4% to -0.2%, p = 0.05) with steroid pretreatment. In post hoc sensitivity analyses, reclassification statistics showed that these factors did not result in significant changes of biomarker levels across clinically used cut-off ranges.

CONCLUSIONS

Despite statistically significant associations of some pre-analytic factors and biomarker levels, a clinically relevant influence seems unlikely. Our observations reinforce the concept of using biomarkers in algorithms with widely-separated cut-offs and overruling criteria considering the entire clinical picture.

TRIAL REGISTRATION

Identifier ISRCTN95122877.

Significance of serum procalcitonin as biomarker for detection of bacterial peritonitis: a systematic review and meta-analysis

Background

Bacterial peritonitis is serious disease and remains a diagnostic challenge for clinicians. Many studies have highlighted the potential usefulness of procalcitonin (PCT) for identification of bacterial peritonitis, however, the overall diagnostic value of PCT remains unclear. Therefore, we performed a meta-analysis to assess the accuracy of PCT for detection of bacterial peritonitis.

Methods

We performed a systematic searched in MEDLINE, EMBASE, SCOPUS, China Biology Medicine Database (CBM), China National Knowledge Infrastructure Database (CNKI) and Cochrane databases for trials that evaluated the diagnostic role of PCT for bacterial peritonitis. Sensitivity, specificity and other measures of accuracy of PCT were pooled using bivariate random effects models.

Results

Eighteen studies involving 1827 patients were included in the present meta-analysis. The pooled sensitivity and specificity of serum PCT for the diagnosis bacterial peritonitis were 0.83 (95% CI: 0.76–0.89) and 0.92 (95% CI: 0.87–0.96), respectively. The positive likelihood ratio was 11.06 (95% CI: 6.31–19.38), negative likelihood ratio was 0.18 (95% CI: 0.12–0.27) and diagnostic odds ratio (DOR) was 61.52 (95% CI: 27.58–137.21). The area under the receiver operating characteristic curve (AUROC) was 0.94. Use of a common PCT cut-off value could improve the DOR to 75.32 and the AUROC to 0.95. Analysis of the seven studies that measured serum C-reactive protein (CRP) indicated that PCT was more accurate than CRP for the diagnosis of bacterial peritonitis.

Conclusions

Our results indicate that PCT determination is a relatively sensitive and specific test for the diagnosis of bacterial peritonitis. However, with regard to methodological limitations and significant heterogeneity, medical decisions should be based on both clinical findings and PCT test results.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2334-14-452) contains supplementary material, which is available to authorized users.

Prevention of infectious complications after heart surgery in children: procalcitonin-guided strategy

Introduction

Infectious complications remain a significant problem of modern cardiac surgery. New prevention strategies, based on the pathogenesis of such complications occurring after cardiopulmonary bypass (CPB) procedures, should be evaluated.

Aim of the study

To evaluate the effectiveness of a procalcitonin (PCT)-guided strategy involving the use of IgM-enriched intravenous immunoglobulins (IVIGs) in children with congenital heart disease with systemic inflammation during the early postoperative period.

Material and methods

Sixty consecutive patients aged 25 (21-30) months who underwent cardiac surgery with CPB and had blood PCT levels > 2 ng/mL on the 1^st postoperative day were enrolled in this single-center prospective randomized clinical trial. The patients were randomized into two groups, comparable in terms of the severity of their initial condition, age, and CPB time. IgM-enriched IVIGs (Pentaglobin, Biotest Pharma GmbH, Germany) were administered during the first 3 postoperative days (5 mL/kg each day) in the study group (n = 30) in addition to the standard treatment, which was also provided to the control group (n = 30). The data are presented as medians with 25-75^th percentiles; they were compared by the Mann-Whitney U-test, and p values of < 0.05 were considered as statistically significant.

Results

Postoperatively, 1/30 (3.3%) patients in the study group and 8/30 (26.7%) in the control group suffered from infectious complications (study group: urinary tract infection [UTI] – 1; control group: pneumonia – 4, pneumonia and sepsis – 2, peritonitis with multiorgan failure – 1, UTI – 1), p = 0.03. The length of hospital stay in the study group was shorter than in the control group: 19 (16-23) days vs. 24 (19-29) days, p = 0.002, as was the length of intensive care unit (ICU) stay: 3 (2-4) days vs. 4 (2-8) days, p = 0.03.

Conclusions

High PCT levels on the 1st postoperative day are associated with an increased risk of infectious complications after cardiac surgery. Early administration of IgM-enriched IVIGs can prevent the development of infectious complications.

Update on procalcitonin measurements

Procalcitonin (PCT) is used as a biomarker for the diagnosis of sepsis, severe sepsis and septic shock. At the same time, PCT has also been used to guide antibiotic therapy. This review outlines the main indications for PCT measurement and points out possible pitfalls. The classic indications for PCT measurement are: (i) confirmation or exclusion of diagnosis of sepsis, severe sepsis, or septic shock, (ii) severity assessment and follow up of systemic inflammation mainly induced by microbial infection, and (iii) individual, patient adapted guide of antibiotic therapy and focus treatment. Using serially monitored PCT levels, the duration and need of antibiotic therapy can be better adapted to the individual requirements of the patient. This individualized approach has been evaluated in various studies, and it is recommended to be a part of an antibiotic stewardship program.

Procalcitonin testing for diagnosis and short-term prognosis in bacterial infection complicated by congestive heart failure: a multicenter analysis of 4,698 cases

Introduction

Procalcitonin (PCT) is a biomarker for the clinical diagnosis of bacterial infection that is more specific and earlier than fever, changes in white blood cell count, and blood cultures. Congestive heart failure is an important cause of endotoxin resorption from the intestine, which significantly increases PCT expression in noninfected patients with heart failure. The diagnostic performance and cut-off value of PCT in patients with bacterial infection complicated by congestive heart failure needs to be confirmed.

Methods

A total of 4,698 cases from different cities in China, including those with different classes of congestive heart failure, bacterial infection, bacterial infection complicated by heart failure and healthy individuals, were chosen for the diagnostic value analysis of PCT and screening candidate predictors of mortality in subjects with bacterial infection complicated by congestive heart failure.

Results

Patients with simple heart failure had significantly higher PCT levels than normal controls (P < 0.01), whereas patients with bacterial infection complicated by congestive heart failure had significantly higher PCT levels than those with simple infection (P < 0.01). Although it was useful for the diagnosis of infection (area under the receiver operating characteristic curve >80%), the positive predictive value of PCT decreased significantly with increasing severity of heart failure (P < 0.05), and the cut-off value of PCT concentrations for infection complicated by classes II, III and IV heart failure were 0.086, 0.192 and 0.657 μg/L, respectively. Heart failure degree, PCT level, and age were the candidate predictors of mortality in patients with bacterial infection complicated by congestive heart failure.

Conclusions

These data suggest that complicated heart failure elevates the PCT level in patients with bacterial infection. Thus, the results of the PCT test must be analyzed correctly in consideration of the severity of heart failure. Close attention should be paid to cardiac function and PCT expression in aged patients with infection complicated by congestive heart failure.

Description and predictive factors of infection in patients with chronic kidney disease admitted to the critical care unit

OBJECTIVES

To describe the spectrum of infection and multidrug-resistant bacterial colonization, and to identify early predictors of infection in patients with chronic kidney disease (CKD) admitted to the critical care unit (CCU).

METHODS

A 7-month observational prospective single-centre study in a French university hospital.

RESULTS

791 patients were admitted to the CCU, 135 of whom (17%) had severe CKD. Among these, 41 (30%) were infected on admission. Infection was microbiologically documented in 32 patients (78%), of which 7 (22%) were related to Pseudomonas aeruginosa. There was no infection related to extended-spectrum β-lactamase-producing enterobacteriaceae despite a 12% carriage rate on admission. A temperature ≥37.6 °C and a leukocyte count >12.000/mm³ were specific but poorly sensitive of infection (91% and 80%, and 45% and 39%, respectively). Using the threshold of 0.85 ng/ml, procalcitonin was a strong independent predictor of infection on admission (OR 12.8, 95% CI 4.4-37.3). Age (≥60 years) and the cause of CKD were two other predictors.

CONCLUSIONS

Infection accounts for one-third of CCU admissions in CKD patients, with a high prevalence of P. aeruginosa. The usual diagnostic criteria are inaccurate for diagnosing infection in this population. A procalcitonin ≥0.85 ng/ml might be helpful for early identifying CKD patients with infection.

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 predictive marker for surgical site infection in elective colorectal cancer surgery

PURPOSE

Surgical site infection (SSI) is a frequent complication of elective surgery for colorectal cancer. The classical clinical markers of infection-elevations in white blood cell count, C-reactive protein (CRP) level, and body temperature-do not precisely predict SSI after elective colorectal resection. The objective of this study was to evaluate the efficacy of procalcitonin (PCT) as a tool for diagnosis of SSI in elective surgery for colorectal cancer.

METHODS

A total of 114 consecutive patients undergoing elective colorectal resection for cancer were evaluated. Routine blood samples, for determining PCT level, CRP plasma concentration, and white blood cell count, were obtained on postoperative days (POD) 1 and 3. Predictive values for each of the laboratory markers were examined.

RESULTS

SSI was diagnosed in 18 (15.7 %) of 114 patients. Patients with SSI exhibited significantly higher PCT levels (on PODs 1 and 3) and CRP levels (on POD 3) than did patients without SSI. According to receiver operating characteristic analysis, PCT showed the highest area under the curve (AUC) for predicting SSI on both PODs 1 and 3 (AUC, 0.76 and 0.77, respectively). Multivariate logistic regression analysis showed that PCT (on PODs 1 and 3) was an independent predictor for SSI (odds ratio = 14.41 and 9.79, respectively).

CONCLUSION

Serum PCT is more reliable laboratory marker for the early diagnosis of SSI after elective colorectal cancer surgery, compared with conventional inflammatory indicators. PCT could serve as an additional diagnostic tool for the early identification of SSI to improve clinical decision making.

Plasma procalcitonin and the risk of cardiovascular events and death: a prospective population-based study

OBJECTIVES

A number of inflammatory biomarkers such as C-reactive protein (CRP) are independent predictors of cardiovascular risk. The inflammatory biomarker procalcitonin (PCT) has previously been shown to be associated with coronary atherosclerosis and the metabolic syndrome. We evaluated the ability of PCT to predict future cardiovascular events in a population of apparently healthy individuals.

DESIGN

We measured plasma PCT levels in 3713 subjects with no previous history of cardiovascular disease, randomly selected from the Malmö Diet and Cancer cohort. The correlation between PCT concentration and the incidence of coronary events, stroke and cardiovascular death over a median follow-up period of 13.7 years was studied using a Cox regression analysis corrected for age, sex, CRP level, traditional risk factors and renal function.

RESULTS

Age and sex were strong determinants of PCT; the concentration of PCT was significantly higher in men than in women. PCT was associated with several of the established cardiovascular risk factors (CRP, hypertension, diabetes and renal function) as determined by multivariate linear regression. Of note, PCT was inversely correlated with HDL and smoking. We found significant correlations between PCT levels, coronary events and cardiovascular death. However, these relationships lost statistical significance when the analysis was corrected for CRP and the traditional risk factors.

CONCLUSIONS

This is the largest population-based prospective study to demonstrate a positive association between plasma PCT levels and cardiovascular risk in subjects with no previous history of acute cardiovascular events. However, the high degree of covariation between PCT and other cardiovascular risk factors limits the value of PCT as an independent cardiovascular risk predictor.

Baseline evaluation of serum markers of inflammation and their utility in clinical practice in paediatric liver transplant recipients

BACKGROUND

Several biomarkers of penetrating infections vs. rejection in liver transplant (LT) have been suggested; however, baseline values in paediatric LT recipients have not been studied.

AIM

We evaluated the baseline concentration of procalcitonin (PCT), C-reactive protein (CRP) and interleukin-6 (IL-6) in a post-LT paediatric group.

METHODS

We measured serum PCT, CRP and IL-6 in 58 consecutive paediatric LT recipients. Specimens were collected for group 1 (n=22) at day 1, group 2 (n=12) at day 7 post-LT and group 3 (n=24) at onset of febrile episode. Day 7 samples were obtained from patients who had no graft dysfunction or signs/symptoms of sepsis.

RESULTS

Median values for PCT were: group 1 was 5.16 μg/L (95% CI, 2.18-21.13); group 2: 0.170 μg/L (95% CI, 0.15-0.36) and, group 3: 1.93 μg/L (95% CI, 1.36-2.66) for bacterial and fungal infection, 0.19 μg/L (95% CI, 0.10-0.48) for rejection, and 0.31 μg/L (95% CI, 0.15-0.44) for viral infection. The area under the ROC (AUROC) for PCT, CRP and IL-6 in bacterial infection vs. rejection was 1.0 (P<0.0001), 0.842 (95% CI 0.686-0.998; P<0.0001) and 0.739 (95% CI 0.559-0.919; P 0.0046), respectively.

CONCLUSION

PCT levels were significantly higher in bacterial and fungal infection in comparison to other inflammatory markers. PCT proved to be the most specific parameter in differentiating bacterial infection from viral infection and allograft rejection.

Serum and pleural fluid procalcitonin in predicting bacterial infection in patients with parapneumonic effusion

This study evaluated the value of procalcitonin (PCT) levels in pleural effusion to differentiate the etiology of parapneumonic effusion (PPE). Forty-one consecutive PPE patients were enrolled and were divided into bacterial and non-bacterial PPE. Blood and pleural effusion samples were collected for PCT measurement on admission and analyzed for diagnostic evaluation. PCT of pleural fluid was significantly increased in the bacterial PPE group (0.24 ng/mL) compared to the non-bacterial PPE group (0.09 ng/mL), but there was no significant difference for serum PCT. A PCT concentration of pleural fluid >0.174 ng/mL (best cut-off value) was considered positive for a diagnosis of bacterial PPE (sensitivity, 80%; specificity, 76%; AUC, 0.84). Pleural effusion PCT in the bacterial PPE is significantly different from those of the non-bacterial PPE and control groups, so the diagnostic use of PCT still warrants further investigation.

[Procalcitonin as an early marker of sepsis]

A 64-year-old male with an APC resistance (factor V mutation Leiden) and interrupted oral anticoagulation due to an erosive gastritis, was admitted to hospital for increasing dyspnoea. Transthoracic echocardiography revealed a floating thrombus via an open foramen ovale in both atria reaching both ventricles. Sonography showed multiple stage thrombosis of the left leg reaching to the V. femoralis superficialis. A few months previously, peripheral pulmonary artery embolization has been confirmed by scintigraphy. The patient was transferred to our hospital and underwent emergency surgery for closure of the atrial septum defect and thrombus removal. On the 4th postoperative day, the patient was transferred to the normal ward, however, on the 10th postoperative day, the patient developed a symptomatic transitory psychotic syndrome and became hypotensive before he was transferred to the ICU. Due to impaired oxygenation and the patient's history, a new pulmonary artery embolization was suspected. After ICU admission, the patient required increasing norepinephrine support and rapidly developed septic fever. However, serum procalcitonin was elevated and a computed tomography (skull, chest and abdomen) was performed for a focus search. Pulmonary artery embolism could be ruled out but an oval structure near to the ampulla recti (ca. 30 x 20 mm) was identified as an abscess and immediate abscess incision was performed. After surgery, the further course was characterized by a steep fall in vasopressor support and body temperature. The patient was transferred to the normal ward on the 2nd postoperative day. This case shows that procalcitonin allows early and reliable diagnosis of sepsis in patients with undefined shock.

Procalcitonin in children with Escherichia coli O157:H7 associated hemolytic uremic syndrome

Shiga toxin producing Escherichia coli (STEC) are noninvasive enteric pathogens that may cause hemorrhagic colitis (HC) and diarrhea-associated hemolytic uremic syndrome (D+ HUS). We hypothesized that development of D+ HUS is associated with increased serum procalcitonin (PCT) levels. PCT was measured by an immunoluminometric assay in 113 patients. Concentrations of PCT were different in normal controls, disease control groups (rotavirus enteritis, HC due to non-STEC pathogens, chronic renal failure), and children with uncomplicated O157:H7 HC or D+ HUS. Children with D+ HUS showed higher PCT levels than those with uncomplicated O157:H7 HC, and increased concentrations were noted in cases requiring peritoneal dialysis. Severely increased concentrations were observed in children with D+ HUS on d 5 or 6 after the onset of enteritis, whereas serial measurements in those with uncomplicated O157:H7 HC remained within the normal range throughout the first week of illness. PCT was correlated with serum concentrations of lipopolysaccharide (LPS)-binding protein and serum levels of alanine aminotransferase. Using two separate sets of real-time PCR primers, we were unable to detect elevated PCT mRNA transcripts in nonadherent undifferentiated (monocytic) or differentiated (macrophage-like) THP-1 cells stimulated with purified Shiga toxin-1 and/or LPS. Our data show that serum levels of PCT are associated with the severity of illness in children with D+ HUS. Further studies are needed to determine the role of PCT in the pathogenesis of thrombotic microangiopathy associated to childhood D+ HUS.

Mannan-binding lectin and procalcitonin measurement for prediction of postoperative infection

Introduction

Postoperative infection is a major cause of morbidity and mortality. We investigated two serum markers for their ability to identify patients at risk for postoperative infection. Mannan-binding lectin (MBL) is a central molecule of the innate immune system and MBL deficiency is known to predispose to infection. Procalcitonin (PCT) is a sensitive marker for bacterial infection.

Methods

We investigated 162 patients undergoing elective surgery for cancer of the gastrointestinal tract. Patients were classified as having no complications (group A), having infection for unknown reason (group B) or having sepsis after events like aspiration or anastomotic leakage (group C). Analysis was done pre- and postoperatively for serum levels of MBL, PCT and C-reactive-protein. DNA was preoperatively sampled and stored and later analysed for genetic polymorphisms of MBL.

Results

The preoperative serum levels of MBL were significantly lower in group B patients than in group A patients (1332 ± 466 ng/ml versus 2523 ± 181 ng/ml). PCT measured on day one post-surgery was significantly higher in group B patients than in group A (3.33 ± 1.08 ng/ml versus 1.38 ± 0.17 ng/ml). Patients with an aberrant MBL genotype had a significantly higher risk of postoperative infections than wild-type carriers (p < 0.05).

Conclusion

Preoperative MBL and early postoperative PCT measurement may help identify patients at risk for postoperative infection.

Clinical laboratory differentiation of infectious versus non-infectious systemic inflammatory response syndrome

OBJECTIVE

To evaluate the accuracy of C-reactive protein (CRP), procalcitonin (PCT), neopterin, and endotoxin in the differential diagnosis of sepsis and non-infectious systemic inflammatory response syndrome (SIRS).

METHODS

A Medline database and references from identified articles were used to perform a literature search relating to the differential diagnosis of sepsis versus non-infectious SIRS.

RESULTS

CRP, PCT, and neopterin are released both in sepsis and in non-infectious inflammatory disease. CRP and PCT are equally effective, although not perfect, in differentiating between sepsis and non-infectious SIRS. However, CRP and PCT have different kinetics and profiles. The kinetics of CRP is slower than that of PCT, and CRP levels may not further increase during more severe stages of sepsis. On the contrary, PCT rises in proportion to the severity of sepsis and reaches its highest levels in septic shock. PCT tends to be higher in nonsurvivor than in survivor. Therefore, PCT demonstrated a closer correlation with the severity of sepsis and outcome than CRP. Unlike CRP and PCT, neopterin is increased in viral infection as well as bacterial infection, and neopterin is also a useful indicator of sepsis. Endotoxemia was detected in no more than half of patients with Gram-negative bacteremia, and Gram-negative bacteremia was detected in half of patients with endotoxemia.

CONCLUSIONS

The diagnostic capacity of PCT is superior to that of CRP due to the close correlation between PCT levels and the severity of sepsis and outcome. Neopterin is very useful in the diagnosis of viral infection. The endotoxin assay in combination with CRP, PCT, or neopterin may help as a diagnostic marker for Gram-negative bacterial infection.

Modulation and Source of Procalcitonin in Reduced Renal Function and Renal Replacement Therapy

Serum procalcitonin (PCT), an accurate marker of severe infection, is moderately increased in chronic kidney disease (CKD), peritoneal dialysis (PD) and haemodialysis (HD). We studied the extent of PCT elevation and factors accounting for elevated PCT in CKD and dialysis, and whether peripheral blood mononuclear cells (PBMC) contribute to increased PCT. In 37 controls, 281 CKD, 31 PD, and 65 HD patients without infection, PCT was measured and correlated with CKD stage, PD, HD, C-reactive protein (CRP), cardiovascular disease (CVD) and other clinical parameters. PCT release by PBMC from controls, advanced CKD, PD and HD patients (12 subjects each) was measured. PCT increased in parallel to the deterioration of CKD. Oliguria, advanced CKD, PD, HD, CVD and elevated CRP were independently associated with PCT elevation. PCT release from PBMC significantly increased in advanced CKD, PD and HD. PCT release from PBMC correlated closely with the corresponding serum PCT values (r=0.76, P <0.001). In the absence of infection, PCT may increase due to reduced renal elimination and increased synthesis, as due to PBMC. Furthermore, serum PCT could serve as a marker of low-grade inflammation and CVD, which substantially increase mortality in CKD and dialysis.

Serum procalcitonin and C-reactive protein levels as markers of bacterial infection: a systematic review and meta-analysis

A meta-analysis was performed to evaluate the accuracy of determination of procalcitonin (PCT) and C-reactive protein (CRP) levels for the diagnosis of bacterial infection. The analysis included published studies that evaluated these markers for the diagnosis of bacterial infections in hospitalized patients. PCT level was more sensitive (88% [95% confidence interval [CI], 80%-93%] vs. 75% [95% CI, 62%-84%]) and more specific (81% [95% CI, 67%-90%] vs. 67% [95% CI, 56%-77%]) than CRP level for differentiating bacterial from noninfective causes of inflammation. The Q value for PCT markers was higher (0.82 vs. 0.73). The sensitivity for differentiating bacterial from viral infections was also higher for PCT markers (92% [95% CI, 86%-95%] vs. 86% [95% CI, 65%-95%]); the specificities were comparable (73% [95% CI, 42%-91%] vs. 70% [95% CI, 19%-96%]). The Q value was higher for PCT markers (0.89 vs. 0.83). PCT markers also had a higher positive likelihood ratio and lower negative likelihood ratio than did CRP markers in both groups. On the basis of this analysis, the diagnostic accuracy of PCT markers was higher than that of CRP markers among patients hospitalized for suspected bacterial infections.

Procalcitonin: improved biochemical severity stratification and postoperative monitoring in severe abdominal inflammation and sepsis

BACKGROUND

Infections and sepsis are among the most devastating complications in abdominal surgery and significantly contribute to morbidity and mortality. Early and reliable diagnosis of septic complications is notoriously difficult, and the search for novel approaches to overcome this problem is still a compelling issue for clinicians. Among a large array of inflammatory parameters, procalcitonin (PCT), the 116-amino-acid pro-peptide of calcitonin, has gained considerable importance in identifying patients at risk of developing infection and sepsis in clinical practice.

METHODS

Along with the latest insights into pathophysiological aspects of this pro-hormone, the literature as well as our own experience on the usefulness of PCT determinations in patients with severe inflammatory abdominal disorders was reviewed.

RESULTS

Although the term "sepsis" does not embrace the integral properties of PCT, a remarkable number of clinical studies have demonstrated the pivotal role of this parameter in the host response to microbial and fungal infections. In acute pancreatitis PCT allows early severity stratification and closely correlates with the development of subsequent pancreatic infections. In patients with peritonitis PCT reflects overall disease severity and is an early and reliable indicator of overall prognosis. Postoperative monitoring of PCT is a helpful tool to identify patients with evolving or persisting septic complications after elective and emergency abdominal surgery.

CONCLUSIONS

Compared with established biochemical routine variables, PCT significantly contributes to earlier and better stratification of patients at risk of developing septic complications and provides excellent prognostic assessment in severe abdominal inflammation. The currently available test systems render PCT an applicable and readily available parameter under clinical routine and emergency conditions.

Pathobiochemistry and clinical use of procalcitonin

Induction of the protein procalcitonin during infection and inflammation was first described approximately 10 years ago. A large number of publications, primarily clinical studies, demonstrate the increasing use of procalcitonin in modern clinical practice. However, data on the biological function and origin of procalcitonin is scarce. Findings regarding the possible role and source of procalcitonin in sepsis and infection were recently published, and the pathophysiology of the protein has meanwhile been investigated in various experimental models. Procalcitonin obviously has certain biological functions, and it is also known to be specifically induced. Given the hormonal origin of the mature protein and the inflammation-related functions of its propeptides, some investigators suggest that procalcitonin should be referred to as a "hormokine," although its biological functions should be studied in more detail. This review will survey the data now available in recent publications on the induction, production sources, possible biological functions and clinical uses of procalcitonin.