Comparison between procalcitonin, serum amyloid A, and C-reactive protein as markers of serious bacterial and fungal infections after solid organ transplantation

Pneumonia in solid organ transplantation: Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

These guidelines from the AST Infectious Diseases Community of Practice review the diagnosis and management of pneumonia in the post-transplant period. Clinical presentations and differential diagnosis for pneumonia in the solid organ transplant recipient are reviewed. A two-tier approach is proposed based on the net state of immunosuppression and the severity of presentation. With a lower risk of opportunistic, hospital-acquired, or exposure-specific pathogens and a non-severe presentation, empirical therapy may be initiated under close clinical observation. In all other patients, or those not responding to the initial therapy, a more aggressive diagnostic approach including sampling of tissue for microbiological and pathological testing is warranted. Given the broad range of potential pathogens, a microbiological diagnosis is often key for optimal care. Given the limited literature comparatively evaluating diagnostic approaches to pneumonia in the solid organ transplant recipient, much of the proposed diagnostic algorithm reflects clinical experience rather than evidence-based data. It should serve as a template which may be modified according to local needs. The same holds true for the suggested empiric therapies, which need to be adapted to the local resistance patterns. Further study is needed to comparatively evaluate diagnostic and empiric treatment strategies in SOT recipients.

Prognostic Value of Procalcitonin, CRP, Serum Amyloid A, Lactate and IL-6 Markers in Liver Transplant Patients Admitted to ED with Suspected Infection

BACKGROUND/AIM

Infections are one of the most important causes of mortality and morbidity after liver transplantation as in all transplantations. Infectious complications are known to be among the preventable causes with appropriate diagnosis and treatment. So early prediction of the risk of infections will provide an effective approach to determine the local antimicrobial resistance and prevention of specific risk factors. The aim of this study was to deterimne whether specific markers are useful or not to deterimne a suspected infection in patients that have undergone liver transplantation.

PATIENTS AND METHODS

The study included 65 patients with liver transplantation admitted to emergency room with suspicion of infection. These patient's CRP, procalsitonin (PCT), lactate, SAA and IL-6 levels were initially measured in the emergency department. The patients were classified to three categories according to culture results; culture-negative, culture-positive and control group. Studying parameters were investigated according to whether the culture was positive or negative in these patients.

RESULTS

CRP, PCT, lactate, SAA and IL-6 levels were significanlty high in patients with suspected infeciton when compared to the control group (p<0.05). CRP, PCT and IL-6 levels were higher in the culture-positive group than in the culture-negative group and there was a significant variation (p<0.05). When suspecting an infection evaluating the parameters CRP, PCT and IL-6 was very meaningfull (p<0.05).

CONCLUSION

We can use CRP, PCT, lactate, SAA and IL-6 parameters to identify presence of infection at the liver transplantation patients admitted to the emergency department with suspected infection. If CRP, PCT and IL-6 levels are significantly high we can guess the patient's positive culture.

Role of biomarkers in early infectious complications after lung transplantation

Background

Infections and primary graft dysfunction are devastating complications in the immediate postoperative period following lung transplantation. Nowadays, reliable diagnostic tools are not available. Biomarkers could improve early infection diagnosis.

Methods

Multicentre prospective observational study that included all centres authorized to perform lung transplantation in Spain. Lung infection and/or primary graft dysfunction presentation during study period (first postoperative week) was determined. Biomarkers were measured on ICU admission and daily till ICU discharge or for the following 6 consecutive postoperative days.

Results

We included 233 patients. Median PCT levels were significantly lower in patients with no infection than in patients with Infection on all follow up days. PCT levels were similar for PGD grades 1 and 2 and increased significantly in grade 3. CRP levels were similar in all groups, and no significant differences were observed at any study time point. In the absence of PGD grade 3, PCT levels above median (0.50 ng/ml on admission or 1.17 ng/ml on day 1) were significantly associated with more than two- and three-fold increase in the risk of infection (adjusted Odds Ratio 2.37, 95% confidence interval 1.06 to 5.30 and 3.44, 95% confidence interval 1.52 to 7.78, respectively).

Conclusions

In the absence of severe primary graft dysfunction, procalcitonin can be useful in detecting infections during the first postoperative week. PGD grade 3 significantly increases PCT levels and interferes with the capacity of PCT as a marker of infection. PCT was superior to CRP in the diagnosis of infection during the study period.

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.

Prognostic and diagnostic value of procalcitonin in the post-transplant setting after liver transplantation

INTRODUCTION

The aim of the study was to assess the diagnostic accuracy of procalcitonin (PCT) as a marker for complications and as a prognostic factor for mortality after liver transplantation.

MATERIAL AND METHODS

Liver transplant patients between January 2007 and April 2011 were prospectively included in the study. Procalcitonin serum concentration was recorded before, 6 h after reperfusion and then daily. Postoperative clinical course was prospectively analyzed from admission to discharge. Main surgical data such as operating procedure, type of reperfusion, operating and ischemic times, high urgency (HU) status and MELD score at the time of transplantation were also recorded.

RESULTS

Sixteen patients with initial PCT > 5 ng/ml suffered ≥ 1 complication (p = 0.03). However, there was no association between the level of the 1(st) peak PCT and the further postoperative course or the occurrence of complications. Patients in whom a 2(nd) PCT peak occurred had a significantly higher risk for a complicated course, for a complicated sepsis course and for mortality (p < 0.0001). Warm ischemic time over 58 min, operating time over 389 min and HU status were significant independent factors for a complicated postoperative course (p < 0.001, p < 0.001 and p = 0.03 respectively).

CONCLUSIONS

Based on our results, we believe that PCT course and the occurrence of a 2(nd) peak seem to possess important diagnostic and prognostic power in the post-transplant setting after liver transplantation.

The use and value of procalcitonin in solid organ transplantation

Procalcitonin (PCT) has been increasingly used as a biomarker of bacterial infection and as a tool to guide antimicrobial therapy, especially in lower respiratory tract and bloodstream infections. Despite its increased use, data in patients with solid organ transplants are limited. Even without the presence of infection, PCT increases as a result of surgical procedures during transplantation, implantation of devices, and use of induction immunosuppressive therapy. The risk of infection is also higher in solid organ transplant recipients when compared to the general population. Monitoring PCT in the early post-transplant period seems to be a promising method for early detection of infectious complications. It has been shown that elevated PCT levels after one wk of transplantation are correlated with infectious complications. PCT may be a useful adjunctive biomarker that may improve early identification and guide appropriate treatment of infection or rejection, with the potential to further improve clinical outcomes. The use of serial PCT measurements may be more reliable than single values. It is important to recognize which factors may lead to PCT increases in the post-transplantation period, which in turn will help understand the kinetics and utility of this biomarker in this important patient population.

Diagnostic value of serum procalcitonin in solid organ transplant recipients: a systematic review and meta-analysis

PURPOSE

To perform a systematic review and meta-analysis to define the role of procalcitonin (PCT) in identifying infectious complication in organ transplant recipients.

METHODS

We searched EMBASE, MEDLINE, the Cochrane database, and reference lists of relevant articles, with no language restrictions, published from inception through May 2013. We selected original research that reported the diagnostic performance of PCT alone or when compared with other biomarkers to diagnose infectious complication among organ transplant recipients. We summarized test performance characteristics with the use of forest plots, hierarchical summary receiver operating characteristic curves, and bivariate random-effects models.

RESULTS

We found 7 qualifying studies (studying 1226 episodes of suspected infection with 186 confirmed infectious episodes) from 4 countries. The patients were lung, kidney, liver, and heart transplant recipients. Bivariate pooled sensitivity, specificity, positive likelihood ratios, and negative likelihood ratios for identification of bacterial infections in patients after transplantation were 85% (95% confidence interval [CI], 75%-92%), 81% (95% CI, 72%-88%), 4.41 (95% CI, 2.86-6.81), and 0.18 (95% CI, 0.10-0.33), respectively. Of the 4 studies that reported the experience of liver transplant patients, the pooled sensitivity, specificity, positive likelihood ratios, and negative likelihood ratios were 90% (95% CI, 75%-97%), 85% (95% CI, 77%-91%), 6.12 (95% CI, 3.79-9.88), and 0.11 (95% CI, 0.04-0.32), respectively. There was no evidence of significant heterogeneity.

CONCLUSION

The existing literature suggests reasonable sensitivity and specificity for the PCT test in identifying infection complications among patients undergoing solid organ transplantation. Given the imperfect sensitivity and specificity of the PCT test, medical decisions should be based on both PCT test results and clinical findings.

Utility of Procalcitonin as a Biomarker for Rejection and Differentiation of Infectious Complications in Lung Transplant Recipients

Objective: To evaluate the utility of procalcitonin (PCT) as a biomarker for rejection and differentiation of infectious complications in lung transplant recipients. Data Sources: An English-language literature search was conducted using MEDLINE (1966-September 2013) using the terms procalcitonin, transplantation, and lung transplantation. Additional articles were identified through a manual search of reference lists of the articles obtained. Study Selection and Data Extraction: All articles evaluating PCT use in lung transplant recipients, including those where lung transplant patients were a subgroup of immunocompromised patients, were included. Data Synthesis: Infection and rejection are leading causes of mortality in lung transplant recipients, with similar clinical presentations; PCT could be a valuable biomarker to differentiate between these complications. Five prospective and 2 retrospective single-center observational evaluations were reviewed. Study populations were diverse, with only 3 focused solely on lung transplant recipients. PCT levels were not elevated during episodes of rejection and viral infections, whereas elevations were seen with bacterial infections. The effect of colonization or fungal infection on PCT varied. Conclusions: Current data suggest that PCT can be used to differentiate bacterial infections from rejection in lung transplant recipients, with unclear utility in colonization or fungal infection. It is reasonable to conclude that PCT values more than 8.18 ng/mL and PCT area under receiver operating curve greater than 0.97 indicate bacterial infection in this population, and PCT trends may increase predictive value. Because of the lack of randomized controlled trials, PCT should only be utilized in conjunction with standard tests for infection and rejection diagnosis.

Procalcitonin in the setting of complicated postoperative course after liver transplantation

BACKGROUND

Orthotopic liver transplantation (OLT) is a treatment for end-stage liver disease. The shortage of available organs leads to the acceptance of marginal grafts, thereby increasing the risk of perioperative complications such as acute rejection, infection, and graft dysfunction Procalcitonin (PCT) has been shown to be a reliable marker for a complicated course after traumatic injury as well as in the courses of systemic inflammatory response syndrome and sepsis. The aim of our study was to evaluate PCT as an early prognostic marker for the occurrence of complication during the postoperative course after OLT.

METHOD

We analyzed PCT levels and clinical and paraclinical data of 32 patients who underwent 33 OLTs. The highest PCT was termed as peak-PCT. Patients were stratified into noncomplication and complication groups. Renal replacement therapy, respiratory insufficiency, postoperative bleeding, refractory ascites, pleural effusion, rejection, sepsis, and fatal outcome were defined as complications. A secondary stratification, using a peak-PCT of 5 ng/mL, was used to analyzed the risk of a complication. We also analyzed the course of PCT after OLT in each group.

RESULTS

The peak-PCT, which occurred between the first and third postoperative day in 30 patients, was followed by halving of the value every second day. Three subjects died because of sepsis. A constantly rising PCT or a secondary rise observed in 2 patients was associated with a fatal outcome. The noncomplication group included 18 patients, 8 of them showing a peakPCT <5 ng/mL and 10 above. The complication group included 14 patients who underwent 15 transplantations; Only 1 displayed a peakPCT <5 ng/mL. When the peak-PCT was >5 ng/mL, the odds ratio of a complication was 11.2 (95% Confidence interval, 10.81-11.59; P < .025). However, not before the 7th postoperative day was the course of mean PCT levels significantly different between the complication and noncomplication groups. In transplant patients, an elevation of PCT was observed only in the presence of bacterial infection and not rejection or wound infection. PCT rose during respiratory failure and sepsis, but not renal replacement therapy, ascites, pleural effusion, rejection, or bleeding.

CONCLUSION

PCT was a reliable marker. A decline was observed in 31 cases with subject, who both had fatal outcomes showing a constantly rising level. An initial high PCT indicated a poor prognosis; some members of the noncomplication group also had levels >15 ng/mL. The patients in the complication group showed a higher mean PCT, which was significant at 7 days, most probably because of the high variation among levels. Still, a peak-PCT >5 ng/mL showed an odds ratio of 11.2 for patients to experience a complication.

Procalcitonin as a prognostic marker for infectious complications in liver transplant recipients in an intensive care unit

Clinically significant infections (CSIs) are life-threatening but difficult to diagnose after liver transplantation (LTx). This study investigates the value of procalcitonin (PCT) in addition to c-reactive protein (CRP) and the leukocyte count (LC) as a prognostic marker for CSIs in LTx recipients. The clinical course of 135 LTx recipients was prospectively studied. CSIs were defined as pulmonary, bloodstream, or intra-abdominal infections. Independent risk factors for CSIs were determined by Cox proportional hazard analysis. The concordance statistics (c-statistics) were used to assess the discrimination effect of PCT. Thirty recipients (22%) experienced a CSI. They had significantly higher peak PCT (27.2 versus 12.7 ng/mL, P = 0.014) and peak CRP (13.7 versus 9.9 mg/dL, P < 0.001) and a tendency toward a higher peak LC (19.3 versus 14.2 cells/nL, P = 0.051) in comparison with recipients without CSIs. Independent risk factors for CSIs were male sex [hazard ratio (HR) = 6.4], a body mass index (BMI) < 20 kg/m(2) (versus a BMI > 25 kg/m(2), HR = 13.8), acute liver failure as an indication for LTx (HR = 7.1), a cold ischemic time > 420 minutes (HR = 3.5), and peak CRP (HR = 1.1) but not peak PCT. The addition of peak PCT marginally improved the c-statistic from 0.815 to 0.827. In conclusion, although peak PCT differed significantly between recipients with and without CSIs, it was not an independent risk factor for CSIs and added little prognostic accuracy. Interestingly, the parameters peak CRP, male sex, low BMI, acute liver failure, and long cold ischemic time were independent risk factors for CSIs. They could serve as risk stratifiers directing medical therapy in clinical practice.

The potential role of C-reactive protein in distinguishing cytomegalovirus from tuberculosis and bacterial infections in renal transplant recipients

INTRODUCTION

The delay in the diagnosis of infections can be deleterious in renal transplant recipients. Thus, laboratory tests leading to an earlier diagnosis are very useful for these patients.

PURPOSE

To assess the behavior of C-reactive protein (CRP) in renal transplant recipients with a diagnosis of cytomegalovirus (CMV) infection, tuberculosis (TB) and bacterial infection (BI).

METHODS

A retrospective analysis of 129 patients admitted at our hospital, from 2006 to 2008 because of CMV, TB or BI, was carried out. Appropriate statistical analysis was done and values were expressed as medians, range.

RESULTS

When CRP levels were compared among the groups with CMV disease, TB or BI, the group with CMV disease presented lower levels of CRP (18.4 mg/L, 0.28-44 mg/L) than the TB and BI (p < 0.05) groups. The area under the receiver-operating characteristics curve, distinguishing CMV disease from TB/BI, was 0.96 (p < 0.0001), resulting in 100% sensitivity and 90.63% specificity to detect CMV disease when CRP < 44.5 mg/L. The subgroup analysis of CMV infection showed increasing levels of CRP (0.28, 16 and 29.5 mg/L) in the asymptomatic, symptomatic and invasive disease subgroups, respectively (p < 0.05).

CONCLUSION

The measurement of CRP levels may be a useful tool for differentiating CMV infection from the other types (bacterial or TB) of infection in kidney transplant recipients.

Diagnostic value and prognostic implications of serum procalcitonin after cardiac surgery: a systematic review of the literature

INTRODUCTION

Systemic inflammatory response syndrome is common after surgery, and it can be difficult to discriminate between infection and inflammation. We performed a review of the literature with the aims of describing the evolution of serum procalcitonin (PCT) levels after uncomplicated cardiac surgery, characterising the role of PCT as a tool in discriminating infection, identifying the relation between PCT, organ failure, and severity of sepsis syndromes, and assessing the possible role of PCT in detection of postoperative complications and mortality.

METHODS

We performed a search on MEDLINE using the keyword 'procalcitonin' crossed with 'cardiac surgery,' 'heart,' 'postoperative,' and 'transplantation.' Our search was limited to human studies published between January 1990 and June 2006.

RESULTS

Uncomplicated cardiac surgery induces a postoperative increase in serum PCT levels. Peak PCT levels are reached within 24 hours postoperatively and return to normal levels within the first week. This increase seems to be dependent on the surgical procedure and on intraoperative events. Although PCT values reported in infected patients are generally higher than in non-infected patients after cardiac surgery, the cutoff point for discriminating infection ranges from 1 to 5 ng/ml, and the dynamics of PCT levels over time may be more important than absolute values. PCT is superior to C-reactive protein in discriminating infections in this setting. PCT levels are higher with increased severity of sepsis and the presence of organ dysfunction/failure and in patients with a poor outcome or in those who develop postoperative complications. PCT levels typically remain unchanged after acute rejection but increase markedly after bacterial and fungal infections. Systemic infections are associated with greater PCT elevation than is local infection. Viral infections are difficult to identify based on PCT measurements.

CONCLUSION

The dynamics of PCT levels, rather than absolute values, could be important in identifying patients with infectious complications after cardiac surgery. PCT is useful in differentiating acute graft rejection after heart and/or lung transplantation from bacterial and fungal infections. Further studies are needed to define cutoff points and to incorporate PCT levels in useful prediction models.

Predictive value of procalcitonin for the diagnosis of bowel strangulation

Intestinal obstruction is responsible for 3% of admissions to hospital emergency surgical departments, but it is difficult to distinguish simple obstruction from strangulation. Simple criteria for this distinction are sought. In this experimental study, procalcitonin, a known marker of bacterial inflammation, was used to detect strangulation. The predictive value of procalcitonin for small bowel strangulation was evaluated. Thirty male New Zealand rabbits (mean weight: 3.0 kg) were divided into three groups. In the first (control) group, only laparatomy was performed. In the second group, simple obstruction was created by ligating a 10-cm distal ileum segment. In the third group, distal strangulation was created by ligating a 10-cm distal ileum segment with the mesentery. Blood (1 cc) was taken from the right auricular vein of each animal for measuring the procalcitonin level. In both the control group and the simple obstruction group the procalcitonin levels were normal. In the strangulation group, elevation of procalcitonin was detected after 30 minutes, and the elevation was statistically significant at 120th minute compared with the control and simple obstruction groups. In patients with small bowel obstruction, measurement of procalcitonin levels is easy to perform and can be used in the follow-up. A more extensive clinical study is needed to evaluate the accuracy of the test as a marker.

Potential risk factors for infection with Candida spp. in critically ill patients

The incidence, risk factors and prognostic factors for candidal infection were determined in a prospective study of 280 infected patients. Thirty-one (11%) patients were infected with Candida spp., sub-divided into 18 (58%) with C. albicans, and 13 (42%) with non-albicans spp. (six C. glabrata, three C. parapsilosis, and one each of C. krusei, C. tropicalis, C. guilliermondii and C. lusitaniae). Infection with Candida spp. was always associated with concurrent bacterial infection. By univariate logistic regression analysis, the degree of morbidity and the duration of mechanical ventilation were independent predictive factors for death, but infection with Candida spp., was not. Factors associated with Candida spp. infection were the degree of morbidity, intensive care unit length of stay, alterations of immune response, and the number of medical devices involved. By multivariate logistic regression analysis, the only independent risk factor for candidal infection was intensive care unit length of stay.

Procalcitonin as a marker of sepsis

Prompt diagnosis and treatment with appropriate antimicrobial chemotherapy is of paramount importance to reduce morbidity and mortality associated with sepsis. Inflammatory markers currently in use, such as C-reactive protein (CRP) do not reliably differentiate between the systemic inflammatory response and sepsis. Procalcitonin (PCT), a precursor of calcitonin, is a 116 amino acid protein that has been proposed as a marker of disease severity in conditions such as septicaemia, meningitis, pneumonia, urinary tract infection (UTI) and fungal and parasitic infection. In particular, serial measurements are useful in order to monitor response to therapy. Together with good clinical judgement and judicious use of antimicrobial agents, PCT should serve as a valuable adjunct in the diagnosis and management of sepsis.