C-reactive protein concentrations during bacteraemia: A comparison between patients with and without liver dysfunction

Innate Immune Zonation in the Liver: NF-κB (p50) Activation and C-Reactive Protein Expression in Response to Endotoxemia Are Zone Specific

Hepatic innate immune function plays an important role in the pathogenesis of many diseases. Importantly, a growing body of literature has firmly established the spatial heterogeneity of hepatocyte metabolic function; however, whether innate immune function is zonated remains unknown. To test this question, we exposed adult C57BL/6 mice to endotoxemia, and hepatic tissue was assessed for the acute phase response (APR). The zone-specific APR was evaluated in periportal and pericentral/centrilobular hepatocytes isolated using digitonin perfusion and on hepatic tissue using RNAscope and immunohistochemistry. Western blot, EMSA, chromatin immunoprecipitation, and immunohistochemistry were used to determine the role of the transcription factor NF-κB in mediating hepatic C-reactive protein (CRP) expression. Finally, the ability of mice lacking the NF-κB subunit p50 (p50-/-) to raise a hepatic APR was evaluated. We found that endotoxemia induces a hepatocyte transcriptional APR in both male and female mice, with Crp, Apcs, Fga, Hp, and Lbp expression being enriched in pericentral/centrilobular hepatocytes. Focusing our work on CRP expression, we determined that NF-κB transcription factor subunit p50 binds to consensus sequence elements present in the murine CRP promoter. Furthermore, pericentral/centrilobular hepatocyte p50 nuclear translocation is temporally associated with zone-specific APR during endotoxemia. Lastly, the APR and CRP expression is blunted in endotoxemic p50-/- mice. These results demonstrate that the murine hepatocyte innate immune response to endotoxemia includes zone-specific activation of transcription factors and target gene expression. These results support further study of zone-specific hepatocyte innate immunity and its role in the development of various disease states.

Ultrastructural evidence of four types of lipofuscins in the melanomacrophagic centers in hepatocytes of zebrafish (Denio rerio)

Melanomacrophagic centers (MMCs) were studied in the hepatocytes of zebrafish using transmission electron microscope (TEM). The MMCs with irregular or amoeboid nucleus were located in the hepatocytes adjacent to the bile canaliculi. Several engulfed structures were present in the cytoplasm of MMCs. The most frequent observation was the presence of mitochondria, ranging in size from small to giant, with distorted shape and inconspicuous cristae. Occasionally the fragments of erythrocytes were found. The rough endoplasmic reticulum (rER) showed whirling around the mitochondria and lipid droplets, forming membrane-like structures. The damaged mitochondria were invaded by the lysosomes, and this was covered by a membrane led to the formation of lipofuscin. Four different types of lipofuscins were observed; namely, (1) granular with/without vacuoles of high electron-density, (2) homogenous surrounded by indistinct limiting membrane, (3) lamellated structures similar to inner matrix and cristae of mitochondria, and, (4) compound structure made by the combinations of first 3 types, (granular and homogenous, granular and lamellated, homogenous and lamellated). The present evidence suggests that MMCs in the hepatocytes of zebrafish perform continuous functions of removal of the damaged cellular organelles. The lipofuscin formation work in coordination with the cellular players of immune system and remove pathogens and maintain the internal homeostasis of cells.

Systemic Inflammation Evaluated by Interleukin-6 or C-Reactive Protein in Critically Ill Patients: Results From the FROG-ICU Study

Background

The prognostic impact of high concentration of interleukin-6 (IL-6) or C-reactive protein (CRP), two routinely available markers of systemic inflammation in the general population of critically ill patients, remains unclear. In a large cohort of critically ill patients including septic and non-septic patients, we assessed the relationship between baseline IL-6 or CRP and mortality, organ dysfunction, and the need for organ support.

Methods

This was an ancillary analysis of the prospective French and euRopean Outcome reGistry in Intensive Care Units (FROG-ICU) study including patients with a requirement for invasive mechanical ventilation and/or vasoactive drug support for more than 24 h following intensive care unit (ICU) admission. The primary objective was to determine the association between baseline IL-6 or CRP concentration and survival until day 90. Secondary outcomes included organ dysfunction as evaluated by the Sequential Organ Failure Assessment (SOFA) score, and the need for organ support, including vasopressors/inotropes and/or renal replacement therapy (RRT).

Results

Median IL-6 and CRP concentrations (n = 2,076) at baseline were 100.9 pg/ml (IQR 43.5–261.7) and 143.7 mg/L (IQR 78.6–219.8), respectively. Day-90 mortality was 30%. High IL-6 or CRP was associated with worse 90-day survival (hazard ratios 1.92 [1.63–2.26] and 1.21 [1.03–1.41], respectively), after adjustment on the Simplified Acute Physiology Score II (SAPS-II). High IL-6 was also associated with the need for organ-support therapies, such as vasopressors/inotropes (OR 2.67 [2.15–3.31]) and RRT (OR 1.55 [1.26–1.91]), including when considering only patients independent from those supports at the time of IL-6 measurement. Associations between high CRP and organ support were inconsistent.

Conclusion

IL-6 appears to be preferred over CRP to evaluate critically ill patients’ prognoses.

Beyond Metabolism: Role of the Immune System in Hepatic Toxicity

The liver is primarily thought of as a metabolic organ; however, the liver is also an important mediator of immunological functions. Key perspectives on this emerging topic were presented in a symposium at the 2018 annual meeting of the American College of Toxicology entitled "Beyond metabolism: Role of the immune system in hepatic toxicity." Viral hepatitis is an important disease of the liver for which insufficient preventive vaccines exist. Host immune responses inadequately clear these viruses and often potentiate immunological inflammation that damages the liver. In addition, the liver is a key innate immune organ against bacterial infection. Hepatocytes and immune cells cooperatively control systemic and local bacterial infections. Conversely, bacterial infection can activate multiple types of immune cells and pathways to cause hepatocyte damage and liver injury. Finally, the immune system and specifically cytokines and drugs can interact in idiosyncratic drug-induced liver injury. This rare disease can result in a disease spectrum that ranges from mild to acute liver failure. The immune system plays a role in this disease spectrum.

Diagnostic and prognostic role of presepsin in patients with cirrhosis and bacterial infection

Objectives

Serum biomarkers have suboptimal accuracy for the early diagnosis of bacterial infection (BI) in cirrhosis.

Aim

To evaluate the diagnostic and prognostic accuracy of presepsin (PSP) in a cohort of hospitalized patients with cirrhosis.

Methods

All adult cirrhotics admitted between 03.2016 and 06.2019 were consecutively evaluated. PSP was measured using chemiluminescent enzyme immunoassay, and its accuracy was compared with that of common biomarkers.

Results

A total of 278 cirrhotic patients for a total of 448 hospitalizations were prospectively collected. Prevalence of BI at admission was 28.3%. Median (range) Log10PSP in the whole cohort was 2.83 (2.48-3.19) ng/L, significantly higher in patients with BI than in patients without (p<0.001). For a cutoff value of 2.87 ng/L, Log10PSP showed sensitivity, specificity and AUC-ROC of 0.66 (95% CI 0.57-0.74), 0.63 (95% CI 0.57-0.68) and 0.69 (95% CI 0.63-0.73), lower than that of C-reactive protein (p=0.002), but similar to procalcitonin (p=0.18) Patients with BI at hospitalization had higher probability of 28-day mortality (sub-hazard ratio [sHR] 2.65;95% CI 1.49-4.70; p=0.001). At multivariate Cox's regression analysis, Log10PSP (sHR 2.4; 95% CI 1.22-4.82; p=0.01) together with age and severity of liver disease, was an independent predictor of short-term mortality.

Conclusions

PSP shows low diagnostic accuracy for BI in cirrhosis, but it is an independent predictor of short-term mortality. PSP may be a biomarker of systemic inflammation, commonly seen in end-stage liver disease.

Development of a novel score for the diagnosis of bacterial infection in patients with acute-on-chronic liver failure

BACKGROUND

The diagnosis of bacterial infection is difficult in patients with acute-on-chronic liver failure (ACLF).

AIM

To evaluate the diagnostic accuracy of widely used parameters for bacterial infection in ACLF and to develop a simple scoring system to improve diagnostic efficiency.

METHODS

This was a retrospective study. Procalcitonin (PCT), white blood cells (WBC), proportion of neutrophils (N%), and C-reactive protein (CRP) were examined. Logistic regression was used to select variables for the scoring models and receiver operating characteristic curve (ROC) analysis was used to evaluate the diagnostic value of different indices.

RESULTS

This study included 386 patients with ACLF, 169 (43.78%) of whom had bacterial infection on admission. The area under the ROC (AUROC) of PCT, CRP, WBC and N% for the diagnosis of bacterial infection ranged from 0.637 to 0.692, with no significant difference between them. Logistic regression showed that only N%, PCT, and CRP could independently predict infection. A novel scoring system (infection score) comprised of N%, PCT and CRP was developed. The AUROC of the infection score was 0.740, which was significantly higher than that for the other four indices (infection score vs N%, PCT, CRP, and WBC, P = 0.0056, 0.0001, 0.0483 and 0.0008, respectively). The best cutoff point for the infection score was 4 points, with a sensitivity of 78.05%, a specificity of 55.29%, a positive predictive value of 57.91% and a negative predictive value of 76.16%.

CONCLUSION

The infection score is a simple and useful tool for discriminating bacterial infection in ACLF.

C-reactive protein at ICU admission as a marker of early graft dysfunction after liver transplant. A prospective, single-center cohort study

OBJECTIVE

To explore the behavior of C-reactive protein (CRP) after orthotopic liver transplantation (OLT) during the first postoperative days, and its usefulness as a marker of severe early allograft dysfunction (EAD).

DESIGN

A prospective, single-center cohort study was carried out.

SETTING

The Intensive Care Unit (ICU) of a regional hospital with a liver transplant program since 1997.

PATIENTS

The study comprised a total of 183 patients admitted to our ICU immediately after liver transplantation between 2009 and 2015.

VARIABLES OF INTEREST

C-reactive protein levels upon ICU admission and after 24 and 48h, severe EAD and hospital mortality.

RESULTS

The CRP levels after OLT were: upon ICU admission 57.5 (51.6-63.3)mg/L, after 24h 80.1 (72.9-87.3)mg/L and after 48h 69.9 (62.5-77.4)mg/L. Severe EAD patients (14.2%) had higher mortality (23.1 vs 2.5; OR 11.48: 2.98-44.19) and lower CRP upon ICU admission (39.3 [29.8-48.7]mg/L) than the patients without EAD (0.5 [53.9-67.0]; p<0.05] - the best cut-off point being 68mg/L (sensitivity 92.3%; specificity 40.1%; Youden index 0.33). Lower CRP upon ICU admission was correlated to higher mortality (24.5 [9.2-39.7] vs 59.4 [53.4-65.4]; p<0.01, AUC 0.79 [0.65-0.92]).

CONCLUSION

Liver transplant is a strong inflammatory stimulus accompanied by high levels of C-reactive protein. A blunted rise in CRP on the first postoperative day after OLT may be a marker of poor allograft function and is related to hospital mortality.

Latent class analysis of ARDS subphenotypes: a secondary analysis of the statins for acutely injured lungs from sepsis (SAILS) study

PURPOSE

Using latent class analysis (LCA), we have consistently identified two distinct subphenotypes in four randomized controlled trial cohorts of ARDS. One subphenotype has hyper-inflammatory characteristics and is associated with worse clinical outcomes. Further, within three negative clinical trials, we observed differential treatment response by subphenotype to randomly assigned interventions. The main purpose of this study was to identify ARDS subphenotypes in a contemporary NHLBI Network trial of infection-associated ARDS (SAILS) using LCA and to test for differential treatment response to rosuvastatin therapy in the subphenotypes.

METHODS

LCA models were constructed using a combination of biomarker and clinical data at baseline in the SAILS study (n = 745). LCA modeling was then repeated using an expanded set of clinical class-defining variables. Subphenotypes were tested for differential treatment response to rosuvastatin.

RESULTS

The two-class LCA model best fit the population. Forty percent of the patients were classified as the "hyper-inflammatory" subphenotype. Including additional clinical variables in the LCA models did not identify new classes. Mortality at day 60 and day 90 was higher in the hyper-inflammatory subphenotype. No differences in outcome were observed between hyper-inflammatory patients randomized to rosuvastatin therapy versus placebo.

CONCLUSIONS

LCA using a two-subphenotype model best described the SAILS population. The subphenotypes have features consistent with those previously reported in four other cohorts. Addition of new class-defining variables in the LCA model did not yield additional subphenotypes. No treatment effect was observed with rosuvastatin. These findings further validate the presence of two subphenotypes and demonstrate their utility for patient stratification in ARDS.

Clarifying the role of C-reactive protein as a bacterial infection predictor in decompensated cirrhosis

INTRODUCTION

Bacterial infections are frequent in cirrhosis and may induce other deleterious complications. Ultrasensitive C-reactive protein (US-CRP), like other acute-phase proteins, is often considered useful in predicting bacterial infection in decompensated cirrhosis. However, US-CRP's reliability remains inconclusive, as inflammation in cirrhosis causes US-CRP synthesis independently of infection. The aim of this study was to clarify US-CRP's role as an infection predictor in decompensated cirrhosis.

PATIENTS AND METHODS

This was a prospective single-center study with systematic inclusion of cirrhotic patients admitted because of decompensation.

RESULTS

A total of 118 patients were enrolled, of whom 47 (39.8%) had an overt infection, defined by clinical and laboratory/imaging criteria. Within those, 17 had infection confirmed by culture bacterial identification. Escherichia coli was the most frequent isolated bacteria. Seventeen patients had spontaneous bacterial peritonitis, but only four (23.5%) had positive ascitic fluid cultures. US-CRP levels were significantly higher in cases of overt infection and positive culture groups than the no infection group (median: 4.14 and 6.40 vs. 1.11 mg/dl, P<0.0001 for both). When considering both overt infection and positive culture groups, the US-CRP values of area under the curve as an infection predictor were, respectively, 0.824 and 0.870, P<0.0001 for both, with associated cutoff values of 2.40 and 3.92 mg/dl, and sensitivity and specificity of 78.7/74.6 and 82.4/79.2%, respectively.

CONCLUSION

The ideal US-CRP infection confirmatory cutoff is probably situated between 2.40 and 3.92 mg/dl. However, as infection is somewhat concealed and hazardous in cirrhotic patients, if not considered with lower US-CRP levels according to specific clinic scenarios, it should be carefully considered, at least, if US-CRP is greater than 2.40 mg/dl (0.5 mg/dl normal upper cutoff).

Detection of bacterial DNA by in situ hybridization in patients with decompensated liver cirrhosis

Background

Spontaneous bacterial peritonitis (SBP) is often difficult to diagnose because bacteria in ascites cannot be detected accurately by conventional culture. In situ hybridization (ISH) was previously developed for rapid detection of genes from bacteria phagocytized by neutrophils. SBP may develop after bacteria enter into the systemic circulation following bacterial translocation. Therefore, we performed ISH to identify bacteria in blood samples collected from patients with decompensated liver cirrhosis (LC).

Methods

In this retrospective study, peripheral blood samples were collected from 60 patients with decompensated LC, and bacteria were detected by both blood culture and ISH. Moreover, 35 patients underwent paracentesis for diagnosis of SBP.

Results

Eight of 35 patients were diagnosed with SBP by polymorphonuclear neutrophil counts, and one patient was diagnosed with bacterascites. Seven of the nine patients showed positive results for ISH, whereas bacteria were detected in only two cases by blood culture. Thirty-seven of 60 cases (62%) showed positive results for ISH, whereas only six samples (10%) were positive by blood culture analysis. Compared with the 23 cases of negative ISH, the 37 cases of positive ISH showed a higher frequency of fever, higher Child-Pugh scores, and lower albumin levels.

Conclusions

Detection of bacteria by ISH suggested that bacterial translocation, which cannot be proven by conventional culture, occurred in these patients, and that ISH could be helpful for the early diagnosis of some types of infection and prevention of SBP in these patients.

Do vitamin D and high-sensitivity-C reactive protein levels differ in patients with hyperemesis gravidarum? A preliminary study

OBJECTIVES

The high sensitivity-C reactive protein (hs-CRP) is an inflammatory marker and vitamin D is an immune modulator that might play a critical role in the pathogenesis of hyperemesis gravidarum. Therefore, in the current study, we tested the hypothesis that suggests women with hyperemesis gravidarum have lower 25-hydroxyvitamin D levels and higher hs-CRP levels, compared to controls.

MATERIALS AND METHODS

This prospective case-control study included 30 women with hyperemesis gravidarum (study group) and 30 age- and body mass index-matched healthy women (control group). The levels of 25-hydroxyvitamin D and hs-CRP were compared between two groups.

RESULTS

Both the serum 25-hydroxyvitamin D (5.30 μg/L vs. 6.44 μg/L; p=0.09) and hs-CRP levels (0.29 mg/dL vs. 0.47 mg/dL; p=0.93) were not significantly different between the study and control groups. Vitamin D deficiency was present in 27 (90.0%) women in the study group and 22 (73.3%) women in the control group (p=0.181). There was also no correlation between 25-hydroxyvitamin D and hs-CRP levels in both groups.

CONCLUSION

Although it did not reach statistical significance, vitamin D levels were lower in the study group compared with controls. Therefore, vitamin D might be speculated to play a crucial role in controlling the inflammatory status associated with hyperemesis gravidarum. Larger studies are required to clarify whether there is a relation between vitamin D deficiency and hyperemesis gravidarum.

Bloodstream infections in patients with liver cirrhosis

Bloodstream infections are a serious complication in patients with liver cirrhosis. Dysregulated intestinal bacterial translocation is the predominant pathophysiological mechanism of infections in this setting. For this reason enteric Gram-negative bacteria are commonly encountered as the first etiological cause of infection. However, through the years, the improvement in the management of cirrhosis, the recourse to invasive procedures and the global spread of multidrug resistant pathogens have importantly changed the current epidemiology. Bloodstream infections in cirrhotic patients are characterized by high mortality rate and complications including metastatic infections, infective endocarditis, and endotipsitis (or transjugular intrahepatic portosystemic shunt-related infection). For this reason early identification of patients at risk for mortality and appropriated therapeutic management is mandatory. Liver cirrhosis can significantly change the pharmacokinetic behavior of antimicrobials. In fact hypoproteinaemia, ascitis and third space expansion and impairment of renal function can be translated in an unpredictable drug exposure.

Hepatocytes: a key cell type for innate immunity

Hepatocytes, the major parenchymal cells in the liver, play pivotal roles in metabolism, detoxification, and protein synthesis. Hepatocytes also activate innate immunity against invading microorganisms by secreting innate immunity proteins. These proteins include bactericidal proteins that directly kill bacteria, opsonins that assist in the phagocytosis of foreign bacteria, iron-sequestering proteins that block iron uptake by bacteria, several soluble factors that regulate lipopolysaccharide signaling, and the coagulation factor fibrinogen that activates innate immunity. In this review, we summarize the wide variety of innate immunity proteins produced by hepatocytes and discuss liver-enriched transcription factors (e.g. hepatocyte nuclear factors and CCAAT/enhancer-binding proteins), pro-inflammatory mediators (e.g. interleukin (IL)-6, IL-22, IL-1β and tumor necrosis factor-α), and downstream signaling pathways (e.g. signal transducer and activator of transcription factor 3 and nuclear factor-κB) that regulate the expression of these innate immunity proteins. We also briefly discuss the dysregulation of these innate immunity proteins in chronic liver disease, which may contribute to an increased susceptibility to bacterial infection in patients with cirrhosis.

Kinetics of interleukin-6, procalcitonin, and C-reactive protein after pediatric liver transplantation

In the early phase after pediatric liver transplantation (pLT) several concomitant factors may reduce the performance of established sepsis markers. To date, their clinical interpretation is hindered by a lack of information on their postoperative kinetics. To gather more information on the postoperative course and their changes in bacterial sepsis, we prospectively studied C-reactive protein (CRP), interleukin-6 (IL-6), and procalcitonin (PCT) on 9 perioperative days in 25 consecutive pLTs. After an initial postoperative peak, IL-6 and CRP levels significantly re-increased in patients with bacterial sepsis (P < .001). In contrast, PCT had very high postoperative levels; therefore severe infection was a comparatively inferior trigger for PCT elevation compared with the initial operation. The area under the receiver operating characteristic curve to diagnose postoperative sepsis for PCT was only 0.52, compared with 0.95 for IL-6 and 0.89 for CRP. None of the studied biomarkers were depressed by poor graft function. In conclusion, PCT performs poorly as a biomarker for sepsis in the early phase after pLT. With a rapid decline of initially elevated levels, IL-6 provides the best kinetics for detection of postoperative bacterial sepsis.

Factors associated with maternal serum C-reactive protein throughout pregnancy: A longitudinal study in women of Rio de Janeiro, Brazil

OBJECTIVES

The aim of this study was to evaluate the longitudinal changes of C-reactive protein (CRP) concentrations during pregnancy and to assess whether socioeconomic, anthropometric, dietary, behavioral, and biochemical factors are associated with these changes.

METHODS

This was a prospective cohort study of 115 adult pregnant women, followed at gestational weeks 5 to 13, 20 to 26, and 30 to 36. Serum concentrations of CRP (mg/L) were measured by the immunoturbidimetric method with ultrasensitive kits (sensitivity 0.05 mg/dL). The statistics included descriptive analysis (mean + SD) and longitudinal linear mixed-effects models, reporting the β coefficient and 95% confidence intervals (CI).

RESULTS

Serum CRP concentrations progressively increased throughout pregnancy (β = 0.121; 95% CI, 0.071-0.171). Parity (β = 1.579; 95% CI, 0.731-2.427) and prepregnancy body mass index (BMI) (β = 0.316; 95% CI, 0.053-0.587) were positively associated and dietary glycemic load was negatively associated (β = -0.203; 95% CI, -0.380 to -0.026) with CRP concentrations in the multiple model. Prepregnancy obese women presented a more pronounced increase of CRP concentrations compared with normal weight women (β = 0.210; 95% CI, 0.059-0.360 versus 0.115, respectively; 95% CI, 0.049-0.181). A statistically significant interaction was observed between parity and gestational age (β = -0.045; 95% CI, -0.084 to -0.005), indicating that the variation of CRP throughout pregnancy differed according to parity categories.

CONCLUSION

CRP concentrations increased throughout pregnancy. Parity and prepregnancy BMI were positively associated and dietary glycemic load was negatively associated with concentrations of CRP.

[Usefulness of procalcitonin for diagnosing infection in critically ill patients with liver cirrhosis]

OBJECTIVE

To evaluate the usefulness of procalcitonin (PCT) for diagnosing infection in patients with liver cirrhosis admitted to an Intensive Care Unit.

DESIGN

A retrospective study was carried out.

SCOPE

Intensive Care Unit. Versatile, twenty-four beds. Participants Patients with liver cirrhosis admitted to our Intensive Care Unit in the last four years with suspected infection and measurement of PCT.

RESULTS

Among the 255 patients with cirrhosis admitted to our unit, PCT was determined for the differential diagnosis of infection in 69 cases (27%). Three patients were excluded from analysis due to a lack of clinical data. The average stay was 10.6 ± 9.2 days, with a mortality rate of 65%. The origin of cirrhosis was mainly viral (57%) or alcoholic (37%). The Child-Pugh and MELD scores were 9.5 ± 2 and 23 ± 8, respectively. Infection was diagnosed in 54 patients (82%). The most common infection was pneumonia (72%), followed by intraabdominal infections (18%) and bacteremia (5%). In patients without infection, the median PCT concentration was 0.57 ng/ml (range 0.28 to 1.14) versus 2.99 (1.31 to 9.4) in those with infection (p<.001). Diagnostic capacity was maintained in patients with intraabdominal infections. The diagnostic cutoff point was set at 0.8 ng/ml (sensitivity 83%, specificity 75%, AUC 0.82 [0.702-0.93]).

CONCLUSIONS

In patients with liver cirrhosis, PCT is useful for identifying bacterial infections, including intraabdominal processes.

Cirrhosis-associated immune dysfunction: distinctive features and clinical relevance

The term cirrhosis-associated immune dysfunction refers to the main syndromic abnormalities of immune function, immunodeficiency and systemic inflammation that are present in cirrhosis. The course of advanced cirrhosis, regardless of its aetiology, is complicated by cirrhosis-associated immune dysfunction and this constitutes the pathophysiological hallmark of an increased susceptibility to bacterial infection, distinctive of the disease. Cirrhosis impairs the homeostatic role of the liver in the systemic immune response. Damage to the reticulo-endothelial system compromises the immune surveillance function of the organ and the reduced hepatic synthesis of proteins, involved in innate immunity and pattern recognition, hinders the bactericidal ability of phagocytic cells. Systemic inflammation, in form of activated circulating immune cells and increased serum levels of pro-inflammatory cytokines, is the result of persistent episodic activation of circulating immune cells from damage-associated molecular patterns, released from necrotic liver cells and, as cirrhosis progresses, from pathogen-associated molecular patterns, released from the leaky gut. Cirrhosis-associated immune dysfunction phenotypes switch from predominantly "pro-inflammatory" to predominantly "immunodeficient" in patients with stable ascitic cirrhosis and in patients with severely decompensated cirrhosis and extra-hepatic organ failure (e.g. acute-on-chronic liver failure), respectively. These cirrhosis-associated immune dysfunction phenotypes represent the extremes of a spectrum of reversible dynamic events that take place during the course of cirrhosis. Systemic inflammation can affect the functions of tissue somatic cells and modify the clinical manifestation of cirrhosis. The best characterized example is the contribution of systemic inflammation to the haemodynamic derangement of cirrhosis, which correlates negatively with prognosis.

Serum procalcitonin and C-reactive protein levels as markers of bacterial infection in patients with liver cirrhosis: a systematic review and meta-analysis

The diagnostic value of procalcitonin (PCT) for patients with liver cirrhosis is unclear. We searched the PubMed, EMBASE, and Cochrane databases for studies published through December 2013 that evaluated the diagnostic performance of PCT for patients with acute or chronic liver disease with suspected systemic infection. We summarized the test performance characteristics by using forest plots, hierarchical summary receiver operating characteristic curves, and bivariate random effects models. Our search identified 230 citations, of which 10 diagnostic studies that evaluated 1144 patients and 435 bacterial infection episodes (32.1%) were ultimately included for analysis. The bivariate pooled sensitivity estimates were 79% (95% confidence interval [CI]: 64%-89%) for PCT tests and 77% (95% CI: 69%-84%) for C-reactive protein (CRP) tests. Pooled specificity estimates were higher for both PCT and CRP tests (PCT, 89% [95% CI: 82%-94%]; CRP, 85% [95% CI: 76%-90%]). The positive likelihood ratio for PCT (LR+, 7.38, 95% CI: 4.70-11.58) was sufficiently high to qualify PCT as a rule-in diagnostic tool, and the negative likelihood ratio for CRP was sufficiently low to qualify CRP as an acceptable rule-out diagnostic tool (LR- 0.23, 95% CI: 0.13-0.41) in patients with no signs of infection. Available clinical evidence showed that PCT has comparable accuracy to CRP for the diagnosis of systemic infection in patients with liver cirrhosis. Compared with patients with normal liver function, both PCT and CRP tests have acceptable accuracy for diagnosing bacterial infection among patients with liver cirrhosis.

Group B streptococcal bacteremia in non-pregnant adults: results from two Korean centers

Patients with liver cirrhosis (LC) have impaired immunity and are, thus, predisposed to infection. Few studies have attempted to evaluate group B streptococcal (GBS) bacteremia in LC patients. A retrospective study of patients with GBS bacteremia was performed at the Dongguk University Ilsan Hospital and National Health Insurance Service Ilsan Hospital over a 13-year period (October 2000 to July 2013). During the study period, 97 patients with GBS bacteremia were enrolled. The median age of the patients was 67 years and 54 % were men. Among them, 23 (24 %) patients were classified as LC patients. The 30-day mortality rate of LC patients was significantly higher than that of patients with other diseases (26 % vs. 8 %, p = 0.03). The multivariate analysis indicated that LC was associated with an increased risk of 30-day mortality [hazard ratio (HR) 5.0; 95 % confidence interval (CI) 1.53-16.3; p = 0.008], as well as age (HR 1.07; 95 % CI 1.03-1.13; p = 0.02) and high Pitt bacteremia score (HR 1.23; 95 % CI 1.02-1.46; p = 0.03). The probability of survival at day 30 was significantly different for the Child-Pugh class C and the Child-Pugh classes A or B (44 % vs. 93 %, respectively; p = 0.01 by the log-rank test). The mortality rates of LC patients with GBS bacteremia were significantly higher than those of patients with other diseases. The severity of hepatic dysfunction plays an important role in the development of adverse events. Cirrhosis-specific scores such as the Child-Pugh class might be useful for predicting the prognosis of GBS bacteremia in LC patients.

High-sensitivity C-reactive protein level is an independent predictor of poor prognosis in cirrhotic patients with spontaneous bacterial peritonitis

BACKGROUND/AIMS

The production of high-sensitivity C-reactive protein (hs-CRP) may be affected by hepatic function, and the clinical importance of hs-CRP in patients with liver cirrhosis is still not clear. The aim of this study was to evaluate the clinical implications of hs-CRP in cirrhotic patients with spontaneous bacterial peritonitis (SBP).

METHODS

We retrospectively investigated 336 consecutive patients treated for SBP from 2007 to 2012. The relationship between serum hs-CRP and the result of the treatment was assessed.

RESULTS

A response to antibiotics was observed in 182 patients (54.2%), and 126 patients (37.5%) died of SBP. The initial hs-CRP (odds ratio=1.061, P=0.016), coexistent hepatocellular carcinoma, and Child-Pugh (CP) score were independent prognostic factors for high in-hospital mortality. Serum hs-CRP level was also an independent predictor of lower antibiotic response rate (odds ratio=0.916, P<0.001). However, hs-CRP was negatively correlated with the CP score (r=-0.199, P<0.001) and Model for End-Stage Liver Disease score (r=-0.182, P=0.001).

CONCLUSIONS

This study found that serum hs-CRP level is related to a lower response rate to antibiotics, a higher mortality rate in patients with SBP. The hs-CRP level was negatively correlated with the CP and Model for End-Stage Liver Disease scores, which suggests that the prognostic function of hs-CRP was not a surrogate for hepatic dysfunction.

Procalcitonin as a Biomarker of the Early Stage of Bacterial Infections in HIV/AIDS Patients

We observed that low concentrations of procalcitonin (PCT) in the early stages of bacterial infection among HIV/AIDS patients are not always associated with a good prognosis. Many of our patients developed sepsis despite a PCT level of <0.5 ng/ml on the first days of infection. The aim of our study was to assess whether laboratory standards for PCT in patients with HIV/AIDS correlate with their clinical condition. We analyzed the concentration of PCT and other inflammatory markers in the early stages of bacterial infection among 40 HIV-infected patients and 52 AIDS patients enrolled for the study. The control group consisted of 37 healthy individuals. In comparison with PCT and WBC, PCT proved to be the most reliable in the early stages of bacterial infection. To conclude, we suggest new PCT cut-off ranges for HIV/AIDS patients with bacterial infection.

Sepsis in AIDS patients: clinical, etiological and inflammatory characteristics

INTRODUCTION

Intensive care mortality of HIV-positive patients has progressively decreased. However, critically ill HIV-positive patients with sepsis present a worse prognosis. To better understand this condition, we propose a study comparing clinical, etiological and inflammatory data, and the hospital course of HIV-positive and HIV-negative patients with severe sepsis or septic shock.

METHODS

A prospective observational study enrolling patients with severe sepsis or septic shock associated or not with HIV infection, and admitted to intensive care unit (ICU). Clinical, microbiological and inflammatory parameters were assessed, including C-reactive protein (CRP), procalcitonin (PCT), interleukin-6, interleukin-10 and TNF-α. Outcome measures were in-hospital and six-month mortality.

RESULTS

The study included 58 patients with severe sepsis/septic shock admitted to ICU, 36 HIV-positive and 22 HIV-negative. All HIV-positive patients met the criteria for AIDS (CDC/2008). The main foci of infection in HIV-positive patients were pulmonary and abdominal (p=0.001). Fungi and mycobacteria were identified in 44.4% and 16.7% of HIV-positive patients, respectively. In contrast, the main etiologies for sepsis in HIV-negative patients were Gram-negative bacilli (36.4%) and Gram-positive cocci (36.4%) (p=0.001). CRP and PCT admission concentrations were lower in HIV-positive patients (130 vs. 168 mg/dL p=0.005, and 1.19 vs. 4.06 ng/mL p=0.04, respectively), with a progressive decrease in surviving patients. Initial IL-10 concentrations were higher in HIV-positive patients (4.4 pg/mL vs. 1.0 pg/mL, p=0.005), with moderate accuracy for predicting death (area under receiver-operating characteristic curve =0.74). In-hospital and six-month mortality were higher in HIV-positive patients (55.6 vs. 27.3% p=0.03, and 58.3 vs. 27.3% p=0.02, respectively).

CONCLUSIONS

The course of sepsis was more severe in HIV-positive patients, with distinct clinical, etiological and inflammatory characteristics.

Management of bacterial infections in cirrhosis

Bacterial infections are very frequent in advanced cirrhosis and become the first cause of death of these patients. Despite numerous experimental data and significant advances in the understanding of the pathogenesis of sepsis in cirrhosis, the outcome remains poor. Classical diagnostic parameters such as C-reactive protein and SIRS criteria have less diagnostic capacity in the cirrhotic population, often delaying the diagnosis and the management of bacterial infection. Prompt and appropriate empirical antibiotic treatment of infection and early resuscitation of patients with severe sepsis or septic shock are essential in determining patient's outcome. A strategy of careful restriction of prophylactic antibiotics to the high-risk populations could reduce the spread of multidrug resistant bacteria. This review is focused on the currently recommended diagnostic, therapeutic and prophylactic strategies for bacterial infections in the cirrhotic population.

C-reactive protein level as a predictor of mortality in liver disease patients with bacteremia

BACKGROUND AND OBJECTIVE

C-reactive protein (CRP) is synthesized in the liver in response to inflammation, and CRP is a widely used marker of sepsis. In bacteremia the initial CRP level is an independent predictor of mortality. Since the CRP response in patients with chronic liver disease is lower than in patients without liver disease the objective was to assess whether CRP levels in chronic liver disease and bacteremia was associated with case fatality.

PATIENTS

The study enrolled 105 patients with chronic liver disease and bacteremia as well as 202 patients with bacteremia and no recorded liver disease from the same region and time period.

METHODS

Retrospective review of medical records with registration of demography, co-morbidity, bacteriological, biochemical and clinical findings, and Child-Turcotte-Pugh scores. The primary outcome was 30-day mortality.

RESULTS

Mortality was significantly higher in patients with chronic liver disease (mortality rate ratio 2.2; 95% confidence interval 1.2-3.9) and it was correlated to Child-Turcotte-Pugh scores. CRP levels were not different between the three Child-Turcotte-Pugh classes (p = 0.33), and no linear correlation with 30-day mortality was observed.

CONCLUSION

Mortality associated with bacteremia is increased in patients with chronic liver disease and it is correlated with Child-Turcotte-Pugh score. The prognostic information of initial CRP levels in patients with chronic liver disease is weak. The clinical management of patients with chronic liver disease and suspected infection should initiate antimicrobial therapy based on clinical, radiological and microbiological findings, whereas the measurement of CRP in bacteremia is less helpful as compared with patients without liver disease.

Usefulness of C-reactive protein for evaluating clinical outcomes in cirrhotic patients with bacteremia

BACKGROUND/AIMS

The purpose of this study was to evaluate the value of initial C-reactive protein (CRP) as a predictor of clinical outcome and to investigate whether follow-up CRP measurement is useful for the prediction of the clinical outcome of bloodstream infections in patients with liver cirrhosis (LC), whose CRP production in response to infection may be attenuated.

METHODS

A retrospective, observational study including 202 LC patients with Escherichia coli or Klebsiella pneumoniae bacteremia was conducted to assess the usefulness of serial CRP measurements in predicting clinical outcome in LC patients. The CRP ratio was defined as the ratio of the follow-up CRP level to the initial CRP level.

RESULTS

The overall 30-day mortality rate of the study population was 23.8% (48/202). In the multivariate analysis, advanced age (≥ 70 years), healthcare-associated or nosocomial infections, model for end-stage liver disease (MELD) score of ≥ 30, and initial body temperature of < 37℃ were significant factors associated with mortality (all p < 0.05). No association between initial CRP level and mortality was found. In a further analysis including 87 evaluable cases who had repeated CRP measurements at day 4 and/or 5, a CRP ratio of ≥ 0.7 was found to be a significant factor associated with mortality (odds ratio, 19.12; 95% confidence interval, 1.32 to 276.86; p = 0.043) after adjusting for other confounding variables.

CONCLUSIONS

Initial CRP level did not predict mortality of sepsis in LC patients. However, serial CRP measurements during the first week of antimicrobial therapy may be useful as a prognostic factor for mortality in LC patients.

Urinary L-type fatty acid-binding protein as a new biomarker of sepsis complicated with acute kidney injury

OBJECTIVE

This study is aimed to examine whether urinary L-type fatty acid-binding protein can detect the severity of sepsis with animal sepsis models and septic shock patients complicated with established acute kidney injury.

DESIGN

Experimental animal models and a clinical, prospective observational study.

SETTING

University laboratory and tertiary hospital.

SUBJECTS AND PATIENTS

One hundred fourteen human L-type fatty acid-binding protein transgenic mice and 145 septic shock patients with established acute kidney injury.

INTERVENTIONS

Animals were challenged by abdominal (cecal ligation and puncture) and pulmonary (intratracheal lipopolysaccharide injection) sepsis models with different severities that were confirmed by survival analysis (n = 24) and bronchoalveolar lavage fluid analysis (n = 38).

MEASUREMENTS AND MAIN RESULTS

In animal experiments, significant increases of urinary L-type fatty acid-binding protein levels were induced by sepsis (severe cecal ligation and puncture 399.0 ± 226.8 μg/g creatinine [n = 12], less-severe cecal ligation and puncture 89.1 ± 25.3 [n = 11], sham 13.4 ± 3.4 [n = 10] at 6 hrs, p < .05 vs. sham; 200 μg of lipopolysaccharide 190.6 ± 77.4 μg/g creatinine [n = 6], 50 μg of lipopolysaccharide 145.4 ± 32.6 [n = 8], and saline 29.9 ± 14.9 [n = 5] at 6 hrs, p < .05 vs. saline). Urinary L-type fatty acid-binding protein predicted severity more accurately than blood urea nitrogen, serum creatinine, and urinary N-acetyl-d-glucosaminidase levels. In clinical evaluation, urinary L-type fatty acid-binding protein measured at admission was significantly higher in the nonsurvivors of septic shock with established acute kidney injury than in the survivors (4366 ± 192 μg/g creatinine [n = 68] vs. 483 ± 71 [n = 77], p < .05). Urinary L-type fatty acid-binding protein showed the higher value of area under the receiver operating characteristic curve for mortality compared with Acute Physiology and Chronic Health Evaluation (APACHE) II and Sepsis-related Organ Failure Assessment (SOFA) scores (L-type fatty acid-binding protein 0.994 [0.956-0.999], APACHE II 0.927 [0.873-0.959], and SOFA 0.813 [0.733-0.873], p < .05).

CONCLUSIONS

Our results suggest that urinary L-type fatty acid-binding protein can be a useful biomarker for sepsis complicated with acute kidney injury for detecting its severity.

Acute-phase proteins as indicators of bacterial infection in patients with cirrhosis

BACKGROUND

Cirrhosis is associated with elevated levels of acute-phase proteins (APP), irrespective of the presence of infection. This condition limits the clinical application of APP determination in cirrhotic patients with bacterial infections.

AIMS

To weigh the diagnostic value of several APP in cirrhotics with or without bacterial infection, and to correlate them with the clinical outcome.

METHODS

We investigated 88 consecutive cirrhotic patients (67 males, 21 females; range 28-85 years) with mean age (SD) 58.9 (13.8) on admission, according to a standard protocol for infection. We measured the following APP: C-reactive protein (CRP), fibrinogen (FIB), haptoglobin (Hpt), ferritin (Fer), beta2-microglobulin (beta2-mg), C3, C4 and C1 inhibitor.

RESULTS

From the 88 patients, 19 (21.6%) had documented infection at the entry based on clinical, radiological and microbiological data. This group of patients did not differ in basic demographics from those without infection. CRP [17.5 (20.7) vs 77.1 (43.9), P<0.001], beta2-mg [4.4 (4.1) vs 5.6 (2.2), P<0.001] and ferritin [461.2 (776.4) vs 825.8 (870), P=0.03] were significantly higher in infection, whereas C3 was significantly lower. No significant differences were noted in the remaining APP levels between the two groups. After receiver operating characteristic curves were fitted, CRP was the best diagnostic test for infection (area under the curve 0.91), followed by beta2-mg, ferritin, FIB, C1 inhibitor, C4, Hpt and C3.

CONCLUSIONS

Serum CRP is the best test, among the examined APP, to discriminate bacterial infection in cirrhotics. A cut-off value of >55.8 mg/L has high sensitivity (79%) and specificity (96%), with the best diagnostic accuracy (92%).

An inhibitor of interleukin-6 trans-signalling, sgp130, contributes to impaired acute phase response in human chronic liver disease

In chronic liver disease, high circulating interleukin (IL)-6 contrasts with a poor acute phase response. We evaluated the impact of liver and circulating IL-6-receptor (IL-6R) forms on IL-6 bioactivity in chronic liver disease. IL-6, soluble IL-6-receptor and sgp130 levels were assayed in plasma from 45 patients with alcoholic liver disease, 84 with hepatitis C virus (HCV) infection undergoing transjugular liver biopsies and 15 healthy subjects. IL-6R mRNA was quantified on liver extracts from 54 patients with alcoholic liver disease with or without cirrhosis and 18 HCV-infected patients. The effect of gp130-Fc on fibrinogen secretion induced by IL-6 trans-signalling was evaluated on hepatocyte cultures. Levels of plasma IL-6 and sgp130, but not soluble IL-6R, increased with the stage of chronic liver disease, and correlated significantly with disease severity. Alcoholic liver disease patients had higher plasma IL-6 levels than hepatitis C, but lower liver IL-6R expression. In alcoholic and HCV-related liver diseases, liver IL-6R expression decreased with advanced fibrosis stage. In vitro, on hepatocytes, gp130-Fc blunted the acute phase response while soluble IL-6R enhanced IL-6 stimulation. In advanced chronic liver disease, high plasma IL-6 is associated with low liver IL-6R expression. This situation enables high plasma sgp130 to act as a major negative regulator of liver IL-6 trans-signalling, as demonstrated functionally here on hepatocytes. This might explain the poor acute phase response induced by IL-6 in chronic liver disease.

C-reactive protein: a poor marker of cardiovascular disease risk in HIV+ populations with a high prevalence of elevated serum transaminases

Blood lipids and high-sensitivity C-reactive protein (hsCRP) are used to assess cardiovascular disease (CVD) risk. We evaluated in a cross-sectional design the relationship of hsCRP to markers of liver function (aspartate and alanine transaminases [AST and ALT, respectively]), CVD risk factors and HIV-disease progression markers in 226 HIV-1 sero-positive drug users. hsCRP showed a significant inverse relationship with ALT and high-density lipoprotein, independent of age, gender, viral load, CD4 cell-count and antiretroviral (ARV) use, and was not significantly associated with HIV-disease progression markers. Serum markers of liver damage, AST and ALT, were associated with lower hsCRP, total cholesterol, low-density lipoproteins and triglycerides. Elevated liver enzymes (> or =40 IU/L) were predictive of hsCRP levels that are considered a low risk for CVD. In conclusion, hsCRP may not be a reliable marker of CVD risk in populations with HIV at-risk for elevated liver enzymes due to high hepatitis B virus/hepatitis C virus prevalence and ARV use.

Advances in pathogenesis and management of sepsis

PURPOSE OF REVIEW

The rationale for therapeutic targets in sepsis has arisen from the concept of pathogenesis. This review focuses on recent advances in pathogenesis of sepsis that can aid in management of sepsis patients.

RECENT FINDINGS

Cellular survival in sepsis is related to the magnitude of the stimulus, the stage of the cell cycle and the type of microbe. While phenotypic modification of the endothelium (procoagulant and proadhesive properties, increased endothelial permeability, endothelial apoptosis and changes in vasomotor properties) leads to vasoplegia as a direct correlate to septic shock mortality, phenotypic changes in the epithelium cause activation of the virulence of the opportunistic pathogens and loss of mucosal barrier function, the latter causing a vicious circle in severe sepsis. Early identification of sepsis with protocolized screening, triggering evidence-based protocolized care, is anticipated to reduce sepsis morbidity and mortality. Current treatment of sepsis includes early antibiotic therapy, early aggressive goal-directed resuscitation targeting tissue hypoperfusion, steroids (for refractory shock), activated protein C (for high risk of death) and maintaining support of organ systems.

SUMMARY

A better understanding of pathogenesis of sepsis has led to specific proven management tools that are likely to improve clinical outcome once incorporated into protocolized care.