Iron Parameters Determine the Prognosis of Critically Ill Patients. Crit Care Med. 2016;44:1049-1058. [PMID: 26934143 DOI: 10.1097/ccm.0000000000001607]

C-Reactive Protein Concentration Can Help to Identify Bacteremia in Children Visiting the Emergency Department: A Single Medical Center Experience

BACKGROUND

For febrile children who are evaluated in a pediatric emergency department (PED), blood culture can be considered the laboratory criterion standard to detect bacteremia. However, high rates of negative, false-positive, or contaminated blood cultures in children often result in this testing being noncontributory. This study determined the factors associated with true-positive blood cultures in children.

METHODS

This retrospective study was conducted at a tertiary medical center's PED. The blood culture use reports were prepared by an infectious disease specialist and were classified as bacteremia, nonbacteremia, and contamination.

RESULTS

We registered a total of 239,459 PED visits during the 8-year period, and 21,841 blood culture samples were taken. Of the laboratory test studies, higher C-reactive protein (CRP) levels and lower hemoglobin levels were observed in the bacteremia group compared with other groups (all P < 0.001). The cut-off value calculated for each age group was adjusted for better clinical usage and significantly improved the blood culture clinical utility documented in the following age groups: 0 to 1 years (CRP level = 30 mg/L, odds ratio [OR] = 5.4, P < 0.001), 1 to 3 years (CRP level = 45 mg/L, OR = 3.7, P < 0.001), and 12 to 18 years (CRP level = 50 mg/L, OR = 6.3, P = 0.006). Using the CRP cut-off value established in this study, we could reduce the blood culture samples in the PED by 14,108 (64.6%).

CONCLUSIONS

This study provides new evidence that CRP may be a useful indicator for blood culture sampling in certain age groups and may help improve the efficiency of blood culture in the PED.

Iron metabolism imbalance at the time of listing increases overall and infectious mortality after liver transplantation

BACKGROUND

Liver transplantation (LT) is the best treatment for patients with liver cancer or end stage cirrhosis, but it is still associated with a significant mortality. Therefore identifying factors associated with mortality could help improve patient management. The impact of iron metabolism, which could be a relevant therapeutic target, yield discrepant results in this setting. Previous studies suggest that increased serum ferritin is associated with higher mortality. Surprisingly iron deficiency which is a well described risk factor in critically ill patients has not been considered.

AIM

To assess the impact of pre-transplant iron metabolism parameters on post-transplant survival.

METHODS

From 2001 to 2011, 553 patients who underwent LT with iron metabolism parameters available at LT evaluation were included. Data were prospectively recorded at the time of evaluation and at the time of LT regarding donor and recipient. Serum ferritin (SF) and transferrin saturation (TS) were studied as continuous and categorical variable. Cox regression analysis was used to determine mortality risks factors. Follow-up data were obtained from the local and national database regarding causes of death.

RESULTS

At the end of a 95-mo median follow-up, 196 patients were dead, 38 of them because of infections. In multivariate analysis, overall mortality was significantly associated with TS > 75% [HR: 1.73 (1.14; 2.63)], SF < 100 µg/L [HR: 1.62 (1.12; 2.35)], hepatocellular carcinoma [HR: 1.58 (1.15; 2.26)], estimated glomerular filtration rate (CKD EPI Cystatin C) [HR: 0.99 (0.98; 0.99)], and packed red blood cell transfusion [HR: 1.05 (1.03; 1.08)]. Kaplan Meier curves show that patients with low SF (< 100 µg/L) or high SF (> 400 µg/L) have lower survival rates at 36 mo than patients with normal SF (P = 0.008 and P = 0.016 respectively). Patients with TS higher than 75% had higher mortality at 12 mo (91.4% ± 1.4% vs 84.6% ± 3.1%, P = 0.039). TS > 75% was significantly associated with infection related death [HR: 3.06 (1.13; 8.23)].

CONCLUSION

Our results show that iron metabolism imbalance (either deficiency or overload) is associated with post-transplant overall and infectious mortality. Impact of iron supplementation or depletion should be assessed in prospective study.

Haptoglobin Therapeutics and Compartmentalization of Cell-Free Hemoglobin Toxicity

Hemolysis and accumulation of cell-free hemoglobin (Hb) in the circulation or in confined tissue compartments such as the subarachnoid space is an important driver of disease. Haptoglobin is the Hb binding and clearance protein in human plasma and an efficient antagonist of Hb toxicity resulting from physiological red blood cell turnover. However, endogenous concentrations of haptoglobin are insufficient to provide protection against Hb-driven disease processes in conditions such as sickle cell anemia, sepsis, transfusion reactions, medical-device associated hemolysis, or after a subarachnoid hemorrhage. As a result, there is increasing interest in developing haptoglobin therapeutics to target 'toxic' cell-free Hb exposures. Here, we discuss key concepts of Hb toxicity and provide a perspective on the use of haptoglobin as a therapeutic protein.

Serum Transferrin Is an Independent Predictor of Mortality in Severe Alcoholic Hepatitis

OBJECTIVES

Severe alcoholic hepatitis (sAH) confers substantial mortality, but the disease course is difficult to predict. As iron parameters are attractive outcome predictors in other liver diseases, we tested their prognostic ability in sAH.

METHODS

Serum ferritin, transferrin, iron, transferrin saturation, nontransferrin-bound iron, soluble transferrin receptor, and hepcidin were measured in 828 patients with sAH recruited prospectively through the STOPAH trial. The cohort was randomly divided into exploratory (n = 200) and validation sets (n = 628).

RESULTS

Patients with sAH had diminished serum transferrin but increased transferrin saturation. Among iron parameters, baseline transferrin was the best predictor of 28-day (area under the receiver operated characteristic 0.72 [95% confidence interval 0.67-0.78]) and 90-day survival (area under the receiver operated characteristic 0.65 [0.61-0.70]). Transferrin's predictive ability was comparable with the composite scores, namely model of end-stage liver disease, Glasgow alcoholic hepatitis score, and discriminant function, and was independently associated with survival in multivariable analysis. These results were confirmed in a validation cohort. Transferrin did not correlate with markers of liver synthesis nor with non-transferrin-bound iron or soluble transferrin receptor (as markers of excess unbound iron and functional iron deficiency, respectively).

DISCUSSION

In patients with sAH, serum transferrin predicts mortality with a performance comparable with commonly used composite scoring systems. Hence, this routinely available parameter might be a useful marker alone or as a component of prognostic models.

Hepcidin and Anemia in Surgical Critical Care: A Prospective Cohort Study

OBJECTIVE

Because anemia of inflammation is common in ICU patients and hepcidin is the key regulator of iron homeostasis, we examined time-dependent changes in hepcidin, erythropoietin, iron, and inflammatory markers in surgical ICU patients with anemia.

DESIGN

Prospective single-center clinical noninterventional study.

SETTING

Surgical ICUs; U.S. university hospital.

PATIENTS

One hundred surgical adult ICU patients.

MEASUREMENTS AND MAIN RESULTS

Time-dependent changes in serum hepcidin, hematologic, and erythropoietic studies were performed on ICU admission and at serial time-points through day 28, and correlated with hematologic and iron parameters and inflammatory response. Median serum hepcidin levels were significantly increased at ICU admission and decreased over time (144-36 ng/mL; p < 0.0001). Despite increased reticulocyte counts (1.3-2.9%), mean serum erythropoietin levels remained low (29-44 mU/mL) and hemoglobin did not significantly change. Hepcidin was positively correlated with RBC transfusion, C-reactive protein, interleukin-6, ferritin, and negatively correlated with iron, total iron binding capacity, transferrin, and reticulocyte response. Hepcidin did not correlate with tumor necrosis factor-α serum concentrations. Regression analyses confirmed that ferritin, C-reactive protein, and reticulocyte number were predictive of same-day hepcidin; hepcidin and C-reactive protein were predictive of same-day reticulocyte count.

CONCLUSIONS

Hepcidin serum concentrations are markedly increased on ICU admission, and decrease significantly over the course of the ICU stay (28 d). Decreased hepcidin concentrations are associated with increased reticulocyte response and decreased inflammatory response reflected by decreased interleukin-6 and C-reactive protein concentrations, but not with anemia resolution.

INtravenous Iron to Treat Anaemia following CriTical care (INTACT): A protocol for a feasibility randomised controlled trial

Background

Anaemia is common in patients who survive critical illness and is associated with high levels of fatigue and poor quality of life. In non-critically ill patients, treating anaemia with intravenous iron has resulted in meaningful improvements in quality of life, but uncertainties regarding the benefits, risks, timing and optimal route of iron therapy in survivors of critical illness remain.

Methods / Design

INtravenous Iron to Treat Anaemia following CriTical care (INTACT) is an open-label, feasibility, parallel group, randomised controlled trial with 1:1 randomisation to either intravenous iron (1000 mg ferric carboxymaltose) or usual medical care. The primary objective is to assess the feasibility of a future, multicentre randomised controlled trial. Participants will be followed up for up to 90 days post-randomisation. The primary outcome measures, which will be used to determine feasibility, are recruitment and randomisation rates, protocol adherence and completeness of follow-up. Secondary outcome measures include collecting clinical, laboratory, health-related quality of life and safety data to inform the power calculations of a future definitive trial.

Conclusion

Improving recovery from critical illness is a recognised research priority. Whether or not correcting anaemia, with intravenous iron, improves health-related quality of life and recovery requires further investigation. If so, it has the potential to become a rapidly translatable intervention. Prior to embarking on a phase III multicentre trial, a carefully designed and implemented feasibility trial is essential.

The clinical value of plasma hepcidin levels in predicting bacterial infections in febrile children

BACKGROUND

Febrile children are often evaluated for the risk of bacterial infections in the pediatric emergency department (PER). Hepcidin is an acute phase inflammatory protein. In this study, we examined the plasma hepcidin levels in febrile children.

METHODS

This study was conducted at a pediatric emergency department with 123 febrile children. We measured plasma hepcidin levels using an enzyme-linked immunosorbent assay. We further evaluated clinical characteristics and routine blood tests along with the hepcidin levels.

RESULTS

We observed significantly higher plasma hepcidin levels in bacterial enteritis (p = 0.026) and combined with urinary tract infection (p = 0.007). Furthermore, hepcidin levels had a significantly positive correlation with CRP level and length of hospital stay (R = 0.296, p = 0.001 and R = 0.213, p = 0.018). Hepcidin levels greater than 65 ng/mL also more accurately predicted bacterial infections than values below 65 ng/mL (11.7% vs. 2.1%, Odds ratio 8.4, 95% confident interval 1.7-40.9, p = 0.002).

CONCLUSION

This study provides evidence that febrile children with bacterial infection have higher plasma hepcidin levels, and the values correlated with CRP level and length of hospital stay. Therefore, hepcidin values can potentially be adopted as a biomarker for identifying febrile children with bacterial infection, particularly bacterial enteritis and urinary tract infection.

The role of hepcidin in regulating iron homeostasis in selected diseases

Iron is an element whose content in the human organism remains under strict control not only due to its involvement in many life processes but also because of its potential toxicity. The latest studies in iron metabolism, especially the involvement of hepcidin, which is the main regulator of iron homeostasis, broadened our knowledge in many medical fields (immunology, nephrology, hematology, gastrology). The present paper is a review of the literature devoted to the importance of hepcidin under selected conditions.

Inflammatory anemia-associated parameters are related to 28-day mortality in patients with sepsis admitted to the ICU: a preliminary observational study

Background

Anemia is one of the most common complications of sepsis. Sepsis-related anemia is associated mainly with inflammation. We aimed to observe the changes in the inflammatory anemia-associated parameters of patients with sepsis in the early stage of intensive care unit (ICU) admission and to evaluate their association with 28-day mortality.

Methods

A total of 198 patients with sepsis were divided into survivor (n = 110) and non-survivor (n = 88) groups on the basis of 28-day survival. Healthy volunteers (n = 20) were enrolled as a control group. Plasma levels of iron, ferritin, erythropoietin (EPO), soluble transferrin receptor (sTfR), hepcidin, interleukin-6 (IL-6), hemoglobin and the red blood cell distribution width (RDW) were measured on days 1, 3 and 7 of ICU admission. Clinical data and laboratory findings were collected, and the Sequential Organ Failure Assessment (SOFA) score was calculated.

Results

Patients with sepsis showed significant decreases in hemoglobin, plasma iron and sTfR/log ferritin and significant increases in plasma EPO, sTfR, hepcidin, ferritin and IL-6 on days 1, 3 and 7 of ICU admission compared with healthy volunteers. Hemoglobin was correlated negatively with plasma IL-6 and hepcidin. In patients with sepsis, non-survivors had significantly lower plasma iron, EPO and sTfR/log ferritin, but higher plasma hepcidin, ferritin and IL-6 than survivors on days 1, 3 and 7 of ICU admission. Plasma EPO, hepcidin, ferritin, IL-6, sTfR/log ferritin, the RDW and SOFA score were associated significantly with 28-day mortality but to a varying extent. In particular, in predicting 28-day mortality, plasma hepcidin had an area under the receiver operating curve of 0.808 and 87.3% specificity, which was the highest among the inflammatory anemia-associated parameters tested.

Conclusions

Inflammatory anemia-associated parameters changed significantly in patients with sepsis in the first week of ICU admission. Plasma EPO, hepcidin, ferritin, IL-6, sTfR/log ferritin, the RDW and SOFA score were associated significantly with 28-day mortality. Plasma hepcidin might have a superior predictive value, with high specificity, compared with other inflammatory anemia-associated parameters for 28-day mortality of sepsis patients in the ICU.

Electronic supplementary material

The online version of this article (10.1186/s13613-019-0542-7) contains supplementary material, which is available to authorized users.

Low Serum Hepcidin Is Associated With Reduced Short-Term Survival in Adults With Acute Liver Failure

The liver has an important role in iron homeostasis through the synthesis of the serum transporter transferrin and the iron hormone hepcidin. The aim of this study was to analyze parameters of iron metabolism in a multicenter cohort of adult patients with acute liver failure (ALF) and in an acetaminophen (APAP)-induced ALF mouse model. A representative subset of 121 adults with ALF (including 66 APAP-related patients) had baseline serum samples tested for ferritin, transferrin, iron, and hepcidin. Outcomes at 3 weeks after enrollment were categorized as spontaneous survivor (SS) versus death/transplantation (NSS). Mice were assessed before (controls) and 4 and 18 hours after injection of 300 mg/kg APAP. Patients with ALF as well as APAP-treated mice displayed increased ferritin and diminished serum hepcidin and hepcidin/ferritin ratio. SS had lower iron (29.1% vs. 34.5 µmol/L; P < 0.05) and transferrin saturation (60.9% vs. 79.1%; P < 0.01), but higher hepcidin levels (8.2 vs. 2.7 ng/mL; P < 0.001) and hepcidin/ferritin ratio (0.0047 vs. 0.0009; P < 0.001) than NSS. In a multivariate analysis, a log-transformed hepcidin-containing model displayed similar prognostic power as the established Acute Liver Failure Study Group index (C-statistic 0.87 vs. 0.85) and was better than Model for End-Stage Liver Disease score (C-statistic 0.76). In mice, hepcidin levels inversely correlated with the surrogate of liver injury. Conclusion: Our findings demonstrate that several serum iron parameters significantly associate with 3-week outcomes in adults with ALF. Among them, hepcidin decreases early during experimental APAP-induced ALF, is an independent predictor and might be a useful component of future prognostic scores.

Diagnostic values of C-reactive protein and complete blood cell to identify invasive bacterial infection in young febrile infants

BACKGROUND

Newborn infants younger than 3 months old with a fever are frequently evaluated for the risk of invasive bacterial infections (IBIs), which include bacteremia and/or bacterial meningitis, in the pediatric emergency department (PED). The purpose of this study was to determine the individual complete blood cell count and biochemistry levels associated with IBIs in febrile infants.

METHODS

We carried out this retrospective study using a pediatric emergency department at a tertiary medical center in southern Taiwan, where we also evaluated the clinical characteristics and routine blood tests between experimental groups.

RESULTS

We enrolled 1231 febrile infants under the age of 3 months old in this study. We found higher body temperature, neutrophil percentage, and C-Reactive protein (CRP) values and a lower hemoglobin level in the IBIs group. Furthermore, a CRP value greater than 25 mg/L can predict IBIs at a better rate than the group with values lower than 25 mg/L (11.7% vs. 2.1%, Odds ratio 6.3, p < 0.001).

CONCLUSION

This study provides evidence that a CRP level greater than 25 mg/L can more accurately predict IBIs in febrile infants. Furthermore, lower hemoglobin levels were also found in IBIs. Nevertheless, additional laboratory tests are needed to identify young febrile infants with IBIs.

Iron Metabolism: An Emerging Therapeutic Target in Critical Illness

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2019. Other selected articles can be found online at https://www.biomedcentral.com/collections/annualupdate2019. Further information about the Annual Update in Intensive Care and Emergency Medicine is available from http://www.springer.com/series/8901.

Tuberculosis-associated anemia is linked to a distinct inflammatory profile that persists after initiation of antitubercular therapy

Pulmonary tuberculosis (PTB) is associated with chronic inflammation and anemia. How anemia impacts systemic inflammation in PTB patients undergoing antitubercular therapy (ATT) is not fully understood. In the present study, data on several blood biochemical parameters were retrospectively analyzed from 118 PTB patients during the first 60 days of ATT. Multidimensional statistical analyses were employed to perform detailed inflammatory profiling of patients stratified by anemia status prior to treatment. Anemia was defined as hemoglobin levels <12.5 g/dL for female and <13.5 g/dL for male individuals. The findings revealed that most of anemia cases were likely caused by chronic inflammation. A distinct biosignature related to anemia was detected, defined by increased values of uric acid, C-reactive protein, and erythrocyte sedimentation rate. Importantly, anemic patients sustained increased levels of several biochemical markers at day 60 of therapy. Preliminary analysis failed to demonstrate association between persistent inflammation during ATT with frequency of positive sputum cultures at day 60. Thus, TB patients with anemia exhibit a distinct inflammatory profile, which is only partially reverted at day 60 of ATT.

The effect of red blood cell transfusion on iron metabolism in critically ill patients

BACKGROUND

Anemia of inflammation (AI) has a high prevalence in critically ill patients. In AI, iron metabolism is altered, as high levels of inflammation-induced hepcidin reduce the amount of iron available for erythropoiesis. AI is treated with red blood cell (RBC) transfusions. The effect of RBC transfusion on iron metabolism during inflammatory processes in adults is unknown. We investigated the effect of RBC transfusion on iron metabolism in critically ill patients.

METHODS

In a prospective cohort study in 61 critically ill patients who received 1 RBC unit, levels of iron variables were determined before, directly after, and 24 hours after transfusion in septic and nonseptic patients.

RESULTS

Serum iron levels were low and increased after transfusion (p = 0.02). However, RBC transfusion had no effect on transferrin saturation (p = 0.14) and ferritin levels (p = 0.74). Hepcidin levels increased after RBC transfusion (p = 0.01), while interleukin-6 levels decreased (p = 0.03). In septic patients, RBC transfusion induced a decrease in haptoglobin levels compared to baseline, which did not occur in nonseptic patients (p = 0.01). The effect of RBC transfusion on other iron variables did not differ between septic and nonseptic patients.

CONCLUSION

Transfusion of a RBC unit transiently increases serum iron levels in intensive care unit patients. The increase in hepcidin levels after transfusion can further decrease iron release from intracellular storage making it available for erythropoiesis. RBC transfusion is associated with a decrease in haptoglobin levels in septic compared to nonseptic patients, but did not affect other markers of hemolysis.

Predictive value of iron parameters in neurocritically ill patients

BACKGROUND

Iron, an essential mineral for human body, has the potential to cause toxicity at high levels. Previous studies have shown inconsistent predictive value of iron parameters in critically ill patients. Thus, we aimed to evaluate the performance of iron parameters in outcome prediction of neurocritically ill patients.

METHODS

Retrospective data were collected from patients admitted to the neurocritical care unit (NCU) of a tertiary teaching hospital between August 2016 and January 2017. The iron parameters were obtained at NCU admission. Primary endpoints were short-term (30-day) mortality and long-term (6-month) poor outcome, with the latter defined as modified Rankin Scale of 4-6. The predictive value of variables was determined with univariate and multivariate logistic analysis. A further subanalysis was conducted in patients stratified by the level of estimated glomerular filtration rate (eGFR).

RESULTS

Of 103 eligible patients, the etiology included stroke (58.2%, N = 60), central nervous system infection (13.6%, N = 14), and other neurologic disorders (28.2%, N = 29). The correlation analysis showed that the increase in ferritin, as well as the reduction in transferrin and total iron-binding capacity, had strong correlation with C-reactive protein, procalcitonin, duration of NCU stay, Acute Physiology and Chronic Health Evaluation II score, and Sequential Organ Failure Assessment score. In a further subanalysis of 75 patients with eGFR ≥ 60 ml/min/1.73 m² , twelve (16.0%) patients died within 30 days and 39 (52.0%) patients achieved good follow-up outcome data. In the multivariate logistic regression analysis, we identified baseline ferritin level as an independent predictor of short-term mortality (OR: 1.002; 95% CI: 1.000-1.003; p = 0.008) and long-term functional outcome (OR: 1.002; 95% CI: 1.000-1.004; p = 0.031).

CONCLUSIONS

Serum ferritin level at admission could be used as an independent predictor of short-term mortality and long-term functional outcome in neurocritically ill patients with eGFR ≥ 60 ml/min/1.73 m² .

Hepcidin predicts response to IV iron therapy in patients admitted to the intensive care unit: a nested cohort study

Background

Both anaemia and red blood cell (RBC) transfusion are common and associated with adverse outcomes in patients admitted to the intensive care unit (ICU). The aim of this study was to determine whether serum hepcidin concentration, measured early after ICU admission in patients with anaemia, could identify a group in whom intravenous (IV) iron therapy decreased the subsequent RBC transfusion requirement.

Methods

We conducted a prospective observational study nested within a multicenter randomized controlled trial (RCT) of IV iron versus placebo. The study was conducted in the ICUs of four tertiary hospitals in Perth, Western Australia. Critically ill patients with haemoglobin (Hb) of < 100 g/L and within 48 h of admission to the ICU were eligible for participation after enrolment in the IRONMAN RCT. The response to IV iron therapy compared with placebo was assessed according to tertile of hepcidin concentration.

Results

Hepcidin concentration was measured within 48 h of ICU admission in 133 patients. For patients in the lower two tertiles of hepcidin concentration (< 53.0 μg), IV iron therapy compared with placebo was associated with a significant decrease in RBC transfusion requirement [risk ratio 0.48 (95% CI 0.26–0.85), p = 0.013].

Conclusions

In critically ill patients with anaemia admitted to an ICU, baseline hepcidin concentration predicts RBC transfusion requirement and is able to identify a group of patients in whom IV iron compared with placebo is associated with a significant decrease in RBC transfusion requirement.

Trial registration

Australian New Zealand Clinical Trials Registry: ANZCTRN12612001249 Registered 26/11/2012

Electronic supplementary material

The online version of this article (10.1186/s40560-018-0328-2) contains supplementary material, which is available to authorized users.

Serum iron levels are an independent predictor of in-hospital mortality of critically ill patients: a retrospective, single-institution study

Objective

This study aimed to examine the relationship between serum iron levels and in-hospital mortality in critically ill patients.

Methods

We retrospectively studied 250 critically ill patients who received treatment at the intensive care unit between June 2015 and May 2017. Blood chemistry and hepatic and renal function were measured. Kaplan–Meier survival curves were plotted according to serum iron levels. Correlations between serum iron levels and other variables were analyzed.

Results

A total of 165 (66.0%) patients had abnormally low serum iron levels (<10.6 μmol/L). Patients who died during hospitalization had markedly higher Acute Physiology and Chronic Health Evaluation II scores and significantly lower serum iron levels compared with those who survived. Cumulative survival was significantly lower in patients with low serum iron levels than in those with normal serum iron levels in subgroup analysis of older patients (n = 192). Multivariate regression analysis showed that, after adjusting for relevant factors, low serum iron levels remained an independent risk for in-hospital mortality (odds ratio 2.014; 95% confidence interval 1.089, 3.725).

Conclusions

Low serum iron levels are present in a significant proportion of critically ill patients and are associated with higher in-hospital mortality, particularly in older patients.

Liver - master and servant of serum proteome

Hepatocytes synthesise the majority of serum proteins. This production occurs in the endoplasmic reticulum (ER) and is adjusted by complex local and systemic regulatory mechanisms. Accordingly, serum levels of hepatocyte-made proteins constitute important biomarkers that reflect both systemic processes and the status of the liver. For example, C-reactive protein is an established marker of inflammatory reaction, whereas transferrin emerges as a liver stress marker and an attractive mortality predictor. The high protein flow through the ER poses a continuous challenge that is handled by a complex proteostatic network consisting of ER folding machinery, ER stress response, ER-associated degradation and autophagy. Various disorders disrupt this delicate balance and result in protein accumulation in the ER. These include chronic hepatitis B infection with overproduction of hepatitis B surface antigen or inherited alpha1-antitrypsin deficiency that give rise to ground glass hepatocytes and alpha1-antitrypsin aggregates, respectively. We review these ER storage disorders and their downstream consequences. The interaction between proteotoxic stress and other ER challenges such as lipotoxicity is also discussed. Collectively, this article aims to sharpen our view of liver hepatocytes as the central hubs of protein metabolism.

High Serum Iron level is Associated with Increased Mortality in Patients with Sepsis

Iron is an essential nutrient for bacterial survival and thus higher iron levels may precipitate bacterial infections. We investigated the association between the serum iron level and prognosis in patients with sepsis by using the single-centre Medical Information Mart for Intensive Care III (MIMIC-III) database. Sepsis patients with iron parameters measured on ICU admission were included and stratified according to quartiles of serum iron levels. A total of 1,891 patients diagnosed with sepsis according to the Sepsis-3 criteria were included in this study, 324 of whom were septic shock. After adjusting for confounding variables, higher iron quartile was associated with an increase in 90-day mortality in the Cox regression analysis. Moreover, a stepwise increase in the risk of 90-day mortality was observed as the quartiles of serum iron levels increased in the patients with sepsis. In conclusion, higher serum iron levels were independently associated with increased 90-day mortality in this large cohort of patients with sepsis.

Iron metabolism in critically ill patients developing anemia of inflammation: a case control study

BACKGROUND

Anemia occurring as a result of inflammatory processes (anemia of inflammation, AI) has a high prevalence in critically ill patients. Knowledge on changes in iron metabolism during the course of AI is limited, hampering the development of strategies to counteract AI. This case control study aimed to investigate iron metabolism during the development of AI in critically ill patients.

METHODS

Iron metabolism in 30 patients who developed AI during ICU stay was compared with 30 septic patients with a high Hb and 30 non-septic patients with a high Hb. Patients were matched on age and sex. Longitudinally collected plasma samples were analyzed for levels of parameters of iron metabolism. A linear mixed model was used to assess the predictive values of the parameters.

RESULTS

In patients with AI, levels of iron, transferrin and transferrin saturation showed an early decrease compared to controls with a high Hb, already prior to the development of anemia. Ferritin, hepcidin and IL-6 levels were increased in AI compared to controls. During AI development, erythroferrone decreased. Differences in iron metabolism between groups were not influenced by APACHE IV score.

CONCLUSIONS

The results show that in critically ill patients with AI, iron metabolism is already altered prior to the development of anemia. Levels of iron regulators in AI differ from septic controls with a high Hb, irrespective of disease severity. AI is characterized by high levels of hepcidin, ferritin and IL-6 and low levels of iron, transferrin and erythroferrone.

Transferrin as a predictor of survival in cirrhosis

Patients with cirrhosis frequently present with high serum ferritin and low transferrin concentrations, reflecting impaired liver function and inflammation. Recent studies have shown that transferrin and its saturation with iron are Model for End-Stage Liver Disease-independent predictors of mortality in patients with acute-on-chronic liver failure or decompensated cirrhosis. The aim of this study was to evaluate the prognostic utility of serum iron parameters in relation to markers of liver function and immune activation. Clinical, demographic, and biochemical data were retrospectively analyzed from a cohort of 1255 consecutive patients with cirrhosis (age ≥ 18 years) who presented from August 1, 2004 until December 31, 2014 at the University Hospital of Innsbruck. Patients with malignancies at diagnosis including hepatocellular carcinoma were excluded. Survival analysis was carried out by Cox regression by using baseline laboratory parameters, and findings were validated in an independent patient cohort. During a median follow-up of 2.4 years, 193 deaths occurred and 254 patients underwent liver transplantation. In patients with transferrin < 180 mg/dL, 3-month, 1-year, and 5-year transplant-free survival estimates were significantly lower (91.7%, 79.0%, and 30.5%) when compared with the group of patients with transferrin ≥ 180 mg/dL (98.9%, 95.5%, and 68.0%, P < 0.001). Transferrin predicted transplant-free survival independently of Model for End-Stage Liver Disease-sodium (MELD-Na) and C-reactive protein (CRP) in multivariate regression analysis including all patients. When patients with alcoholic or nonalcoholic fatty liver disease were excluded, transferrin was in addition an albumin-independent predictor of transplant-free survival. In conclusion, the association of transferrin with transplant-free survival is independent of MELD-Na score and CRP. In patients without fatty liver disease, transferrin also predicts survival independently of albumin. Liver Transplantation 24 343-351 2018 AASLD.

Pathological Role and Diagnostic Value of Endogenous Host Defense Peptides in Adult and Neonatal Sepsis: A Systematic Review

BACKGROUND

Sepsis is a systemic host response to an infection leading to organ failure. This is associated with dynamic expression of endogenous host defense peptides. Dysregulation of these peptides is associated with septic morbidity and mortality.

METHODS

We performed a systematic search of articles indexed in PubMed, ISI Web of Knowledge, EmBase, and Scopus database from inception to October 2016. Both preclinical and clinical studies investigating the role of host defense peptides in pathogenesis and as biomarkers for sepsis were included.

RESULTS

Of the available literature, cathelicidin, defensin, and hepcidin are among the best-characterized peptides. These regulate immune response, and crosstalk with pyroptosis and coagulation cascades. The applicability of these peptides as septic biomarkers has been investigated in vitro and in vivo studies. However, numerous studies were based on endotoxemia without an infection, jeopardizing interpretation of the outcomes. Cathelicidin and defensin were frequently reported in adult sepsis while hepcidin in neonatal sepsis. The expression level of these peptides is significantly associated with septic condition. Most of the studies employed a cross-sectional design, precluding the establishment of a temporal relationship between candidate peptide biomarkers and sepsis.

CONCLUSIONS

Innate defense peptides have been insufficiently evaluated as either diagnostic or prognostic biomarkers. In the future, evaluation of host defense peptides as septic biomarkers may employ a longitudinal design and consider a panel of multiple peptides.

Prognostic implications of low transferrin saturation in patients with primary myelofibrosis

OBJECTIVES

Transferrin saturation (TSAT) 20% or less is considered to represent functional iron deficiency in the context of malignant disease, phenomenon mediated through inflammatory changes of iron homeostasis. We aimed to investigate clinical and prognostic significance of low TSAT in patients with primary (PMF) and secondary myelofibrosis (SMF), malignant diseases characterized by strong inflammatory milieu.

METHODS

We retrospectively analyzed 87 patients with myelofibrosis and compared TSAT with disease specific parameters.

RESULTS

One-third of patients had TSAT ≤20%. Lower TSAT was significantly associated with Janus-kinase-2 (JAK2) mutation (P = 0.007), transfusion independency (P = 0.003), higher platelets (P = 0.004), lower mean-corpuscular-volume (P < 0.001), lower ferritin (P < 0.001), higher absolute-neutrophil-count (P = 0.027), lower absolute-lymphocyte-count (P = 0.041) and lower albumin (P = 0.018). PMF patients presenting with low TSAT (≤20%) experienced significantly shorter overall-survival (OS) (HR = 2.43; P = 0.017), whereas TSAT did not affect OS of SMF patients (HR = 1.48; P = 0.623). Low TSAT remained significantly associated with inferior OS in PMF in a series of multivariate Cox regression models comparing its properties to anemia, transfusion dependency, ferritin and Dynamic-International-Prognostic-System (DIPSS).

CONCLUSIONS

Low TSAT has detrimental effect on survival of PMF patients. This effect is independent of anemia and of ferritin levels that seem to be better at representing iron overload in PMF patients.

Correlation of HAMP gene polymorphisms and expression with the susceptibility and length of hospital stays in Taiwanese children with Kawasaki disease

Kawasaki disease (KD) is a form of systemic vasculitis. Regarding its pathogenesis, HAMP gene encoding hepcidin, which is significant for iron metabolism, has a vital function. In this study, we recruited a total of 381 KD patients for genotyping. Data from 997 subjects (500 subjects from cohort 1; 497 subjects from cohort 2) were used for analysis. Using TaqMan allelic discrimination, we determined five tag SNPs (rs916145, rs10421768, rs3817623, rs7251432, and rs2293689). Treatment outcome data related to such clinical phenotypes as coronary artery lesions (CAL), coronary artery aneurysms (CAA), and intravenous immunoglobulin (IVIG) effects were also collected. Furthermore, we measured plasma hepcidin levels with an enzyme-linked immunosorbent assay. We found that HAMP gene polymorphism (rs7251432, and rs2293689) was significantly correlated with KD risk and that plasma hepcidin levels both before and after IVIG treatment had a significantly positive correlation with length of hospital stays (R = 0.217, p = 0.046 and R = 0.381, p < 0.0001, respectively). In contrast, plasma hepcidin levels has a negative correlation with KD patients' albumin levels (R = -0.27, p < 0.001) prior to IVIG treatment. This study's findings indicate that HAMP might have a role in the disease susceptibility, as well as its expressions correlated length of hospital stays, and albumin levels in Taiwanese children with KD.

Sustained elevated levels of C-reactive protein and ferritin in pulmonary tuberculosis patients remaining culture positive upon treatment initiation

Background

Clinical trials that evaluate new anti-tubercular drugs and treatment regimens take years to complete due to the slow clearance of Mycobacterium tuberculosis infection and the lack of early biomarkers that predict treatment outcomes. Host Inflammation markers have been associated with tuberculosis (TB) pathogenesis. In the present study, we tested if circulating levels of C-reactive protein (CRP) and ferritin reflect mycobacterial loads and inflammation in pulmonary TB (PTB) patients undergoing anti-tuberculous therapy (ATT).

Methods

Prospective measurements of CRP and ferritin, used as readouts of systemic inflammation, were performed in cryopreserved serum samples from 165 Brazilian patients with active PTB initiating ATT. Associations between levels of these laboratory parameters with mycobacterial loads in sputum as well as with sputum conversion at day 60 of ATT were tested.

Results

Circulating levels of both ferritin and CRP gradually decreased over time on ATT. At pre-treatment, concentrations of these parameters were unable to distinguish patients with positive from those with negative acid-fast bacilli (AFB) in sputum cultures. However, patients who remained with positive cultures at day 60 of ATT exhibited heightened levels of these inflammatory markers compared to those with negative cultures at that time point.

Conclusions

CRP and Ferritin levels in serum may be useful to identify patients with positive cultures at day 60 of ATT.

Low serum transferrin correlates with acute-on-chronic organ failure and indicates short-term mortality in decompensated cirrhosis

BACKGROUND & AIMS

Iron represents an essential, but potentially harmful micronutrient, whose regulation has been associated with poor outcome in liver disease. Its homeostasis is tightly linked to oxidative stress, bacterial infections and systemic inflammation. To study the prognostic short-term significance of iron parameters in a cohort study of patients with decompensation of cirrhosis at risk of acute-on-chronic liver failure (ACLF).

METHODS

Ferritin, transferrin, iron, transferrin saturation (TSAT) and hepcidin were determined in sera from 292 German patients hospitalized for decompensation of cirrhosis with ascites, of which 78 (27%) had ACLF. Short-term mortality was prospectively assessed 30 and 90 days after inclusion.

RESULTS

Transferrin concentrations were significantly lower, whereas ferritin and TSAT were higher in patients with ACLF compared to patients without ACLF (P≤.006). Transferrin, TSAT and ferritin differentially correlated with the severity of organ failure, active alcoholism and surrogates of systemic inflammation and macrophage activation. As compared with survivors, 30-day non-survivors displayed lower serum transferrin (P=.0003) and higher TSAT (P=.003), whereas 90-day non-survivors presented with higher ferritin (P=.03) and lower transferrin (P=.02). Lower transferrin (continuous or dichotomized at 87 mg/dL) and consecutively higher TSAT (continuous or dichotomized >41%) indicated increased mortality within 30 days and remained significant after adjustment for organ failure and inflammation in multivariate regression models and across subgroups of patients.

CONCLUSION

Among the investigated indicators of iron metabolism, serum transferrin concentration was the best indicator of organ failure and an independent predictor of short-term mortality at 30 days.

Liver - guardian, modifier and target of sepsis

Sepsis and septic shock are characterized by life-threatening organ dysfunction caused by a dysregulated host response to infection. The liver has a central role during sepsis, and is essential to the regulation of immune defence during systemic infections by mechanisms such as bacterial clearance, acute-phase protein or cytokine production and metabolic adaptation to inflammation. However, the liver is also a target for sepsis-related injury, including hypoxic hepatitis due to ischaemia and shock, cholestasis due to altered bile metabolism, hepatocellular injury due to drug toxicity or overwhelming inflammation, as well as distinct pathologies such as secondary sclerosing cholangitis in critically ill patients. Hence, hepatic dysfunction substantially impairs the prognosis of sepsis and serves as a powerful independent predictor of mortality in the intensive care unit. Sepsis is particularly problematic in patients with liver cirrhosis (who experience increased bacterial translocation from the gut and impaired microbial defence) as it can trigger acute-on-chronic liver failure - a syndrome with high short-term mortality. Here, we review the importance of the liver as a guardian, modifier and target of sepsis, the factors that contribute to sepsis in patients with liver cirrhosis and new therapeutic strategies.

[Hospital-acquired anemia: Facts, consequences and prevention]

Hospital-acquired anemia is common, especially in the most critically ill patients. It may be associated with poor patient outcomes. It may result from increased blood loss, impaired red cell production or reduced red cell life span. Multiple associated factors may contribute simultaneously or sequentially to the decrease in hemoglobin level. Some of them are related to the underlying disease and others are iatrogenic. Clinicians should be aware of the importance and consequences of iatrogenic anemia caused by diagnostic blood sampling. Strategies and measures to minimize iatrogenic blood loss should be prioritized. They may reduce the risk of developing anemia and then red blood cells transfusion requirement.