Serum interleukin-18 at commencement of renal replacement therapy predicts short-term prognosis in critically ill patients with acute kidney injury

Association between early, small creatinine elevation and severe acute kidney injury in critically ill adult patients

BACKGROUND

Early prediction of AKI is crucial for critically ill patients. We investigated the association between small increase in creatinine and subsequent severe AKI in ICU patients.

METHODS

We conducted this retrospective cohort with a multi-institutional database between 2007 and 2019. We included adult patients admitted to the ICU with creatinine changes that did not meet the criteria for AKI diagnosis within 48 h of ICU admission. The outcomes were stage 2 or 3 AKI, kidney replacement therapy, and mortality.

RESULTS

We identified 44,805 patients and divided them into 3 groups by baseline creatinine levels: <1 mg/dL, 1 to 2 mg/dL, and ≥ 2 mg/dL. Compared with patients with higher baseline creatinine levels, patients with normal baseline creatinine levels had fewer comorbidities and less severe condition at ICU admission. The odds ratios of their outcomes increased exponentially with creatinine elevation within the first 48 h of ICU admission. The increasing odds ratios were more prominent in patients with normal baseline creatinine (P for interaction <0.001).

CONCLUSION

Small creatinine elevation within the first 48 h of ICU admission was strongly associated with the AKI, kidney replacement therapy, and death. This association was more prominent in patients with normal baseline creatinine.

Assessment of APACHE II Score to Predict ICU Outcomes of Patients with AKI: A Single Center Experience from Haryana, North India

Background

The acute physiology and chronic health evaluation (APACHE) II severity score has shown a good calibration and discriminatory value across a range of disease processes and remains the most widely used source of prognostic information on the risk for death in patients admitted to intensive care units (ICUs).

Objectives

To study APACHE II scores in patients of acute kidney injury (AKI) admitted in the ICU and to find its association with outcome.

Materials and methods

One hundred patients with AKI aged 18 years or above were admitted in the ICU, department of general medicine, of a tertiary care institute in Haryana, North India, from October 2019 to September 2020, were studied. Patients who had known causes of chronic kidney disease (CKD), on maintenance hemodialysis, and those who underwent renal replacement therapy (RRT) or nephrectomy were excluded. All required investigations were performed, and data were collected. The patients were followed till discharge or in-hospital mortality.

Results

The mean age of the patients was 55.92 ± 18.18 years. Male–female ratio was 1.5:1. Thirty-five percent of the admitted patients had an in-hospital mortality. Sepsis (47%) was the most common cause of AKI, and 83% of the patients had underlying comorbid conditions. The mean APACHE II score of the expired patients on admission, i.e., 24.80 ± 13.65, was found to be significantly higher compared to the mean APACHE II score (17.25 ± 10.12) of the discharged patients (p-value <0.001). APACHE II score was found to have 57.14% sensitivity, 86.15% specificity, 69% PPV, 78.9% NPV, and 76% diagnostic accuracy to predict mortality among the AKI patients.

Conclusion

APACHE II scoring system has a good discrimination and calibration when applied to ICU-admitted AKI patients and is a good predictor of prognosis in them.

How to cite this article

Patel P, Gupta S, Patel H, Bashar MDA. Assessment of APACHE II Score to Predict ICU Outcomes of Patients with AKI: A Single-center Experience from Haryana, North India. Indian J Crit Care Med 2022;26(3):276–281.

Complement Blockade in Recipients Prevents Delayed Graft Function and Delays Antibody-mediated Rejection in a Nonhuman Primate Model of Kidney Transplantation

BACKGROUND

Complement activation in kidney transplantation is implicated in the pathogenesis of delayed graft function (DGF). This study evaluated the therapeutic efficacy of high-dose recombinant human C1 esterase inhibitor (rhC1INH) to prevent DGF in a nonhuman primate model of kidney transplantation after brain death and prolonged cold ischemia.

METHODS

Brain death donors underwent 20 h of conventional management. Procured kidneys were stored on ice for 44-48 h, then transplanted into ABO-compatible major histocompatibility complex-mismatched recipients. Recipients were treated with vehicle (n = 5) or rhC1INH 500 U/kg plus heparin 40 U/kg (n = 8) before reperfusion, 12 h, and 24 h posttransplant. Recipients were followed up for 120 d.

RESULTS

Of vehicle-treated recipients, 80% (4 of 5) developed DGF versus 12.5% (1 of 8) rhC1INH-treated recipients (P = 0.015). rhC1INH-treated recipients had faster creatinine recovery, superior urinary output, and reduced urinary neutrophil gelatinase-associated lipocalin and tissue inhibitor of metalloproteinases 2-insulin-like growth factor-binding protein 7 throughout the first week, indicating reduced allograft injury. Treated recipients presented lower postreperfusion plasma interleukin (IL)-6, IL-8, tumor necrosis factor-alpha, and IL-18, lower day 4 monocyte chemoattractant protein 1, and trended toward lower C5. Treated recipients exhibited less C3b/C5b-9 deposition on day 7 biopsies. rhC1INH-treated animals also trended toward prolonged mediated rejection-free survival.

CONCLUSIONS

Our results recommend high-dose C1INH complement blockade in transplant recipients as an effective strategy to reduce kidney injury and inflammation, prevent DGF, delay antibody-mediated rejection development, and improve transplant outcomes.

Biomarkers for Diagnosis and Prediction of Outcomes in Contrast-Induced Nephropathy

Background

Serum creatinine is suboptimal as a biomarker in the early diagnosis of contrast-induced nephropathy (CIN). In this study, we investigated a panel of novel biomarkers in the early diagnosis of CIN and in assessing patient outcomes.

Methods

This single-centre, nested, prospective case-controlled study included 30 patients with CIN and 60 matched controls. Serum and urine samples were collected before contrast administration and at 24 hours, 48 hours, and ≥5 days after contrast administration. Concentrations of NGAL, cystatin C, β₂M, IL18, IL10, KIM1, and TNFα were determined using Luminex and ELISA assays. Outcomes were biomarker diagnostic discrimination performance for CIN and mortality after generation of area under receiver operating characteristic curves (AUROCs).

Results

Median serum levels for 24 h cystatin C (p < 0.01) and 48 h β₂M levels (p < 0.001) and baseline urine NGAL (p=0.02) were higher in CIN patients compared to controls with AUROCs of 0.75, 0.78, and 0.74, respectively, for the early diagnosis of CIN. Serum β₂M levels were higher in CIN patients at all time points. Elevated baseline serum concentrations of IL18 (p < 0.001), β₂M (p=0.04), TNFα (p < 0.001), and baseline urine KIM (p=0.01) and 24 h urine NGAL (p=0.02) were significantly associated with mortality. Baseline serum concentrations of IL18, β₂M, and TNFα showed the best discrimination performance for mortality with AUROCs, all >0.80. Baseline NGAL was superior for excluding patients at risk for CIN, with positive and negative predictive ranges of 0.50–0.55 and 0.81–0.88, respectively. Cystatin C (p=0.003) and β₂M (p=0.03) at 24 h independently predicted CIN risk. β₂M predicted increased mortality of 40% at baseline and 50% at 24 hours.

Conclusion

Serum cystatin C at 24 h was the best biomarker for CIN diagnosis, while baseline levels of serum IL18, β₂M, and TNFα were best for predicting prognosis.

Outcome Prediction of Acute Kidney Injury Biomarkers at Initiation of Dialysis in Critical Units

: The ideal circumstances for whether and when to start RRT remain unclear. The outcome predictive ability of acute kidney injury (AKI) biomarkers measuring at dialysis initializing need more validation. This prospective, multi-center observational cohort study enrolled 257 patients with AKI undergoing renal replacement therapy (RRT) shortly after admission. At the start of RRT, blood and urine samples were collected for relevant biomarker measurement. RRT dependence and all-cause mortality were recorded up to 90 days after discharge. Areas under the receiver operator characteristic (AUROC) curves and a multivariate generalized additive model were applied to predict outcomes. One hundred and thirty-five (52.5%) patients died within 90 days of hospital discharge. Plasma c-terminal FGF-23 (cFGF-23) had the best discriminative ability (AUROC, 0.687) as compared with intact FGF-23 (iFGF-23) (AUROC, 0.504), creatinine-adjusted urine neutrophil gelatinase-associated lipocalin (AUROC, 0.599), and adjusted urine cFGF-23 (AUROC, 0.653) regardless whether patients were alive or not on day 90. Plasma cFGF-23 levels above 2050 RU/mL were independently associated with higher 90-day mortality (HR 1.76, p = 0.020). Higher cFGF-23 levels predicted less weaning from dialysis in survivors (HR, 0.62, p = 0.032), taking mortality as a competing risk. Adding cFGF-23 measurement to the AKI risk predicting score significantly improved risk stratification and 90-day mortality prediction (total net reclassification improvement = 0.148; p = 0.002). In patients with AKI who required RRT, increased plasma cFGF-23 levels correlated with higher 90-day overall mortality after discharge and predicted worse kidney recovery in survivors. When coupled to the AKI risk predicting score, cFGF-23 significantly improved mortality risk prediction. This observation adds evidence that cFGF-23 could be used as an optimal timing biomarker to initiate RRT.

Overview of the IL-1 family in innate inflammation and acquired immunity

The interleukin-1 (IL-1) family of cytokines and receptors is unique in immunology because the IL-1 family and Toll-like receptor (TLR) families share similar functions. More than any other cytokine family, the IL-1 family is primarily associated with innate immunity. More than 95% of living organisms use innate immune mechanisms for survival whereas less than 5% depend on T- and B-cell functions. Innate immunity is manifested by inflammation, which can function as a mechanism of host defense but when uncontrolled is detrimental to survival. Each member of the IL-1 receptor and TLR family contains the cytoplasmic Toll-IL-1-Receptor (TIR) domain. The 50 amino acid TIR domains are highly homologous with the Toll protein in Drosophila. The TIR domain is nearly the same and present in each TLR and each IL-1 receptor family. Whereas IL-1 family cytokine members trigger innate inflammation via IL-1 family of receptors, TLRs trigger inflammation via bacteria, microbial products, viruses, nucleic acids, and damage-associated molecular patterns (DAMPs). In fact, IL-1 family member IL-1a and IL-33 also function as DAMPs. Although the inflammatory properties of the IL-1 family dominate in innate immunity, IL-1 family member can play a role in acquired immunity. This overview is a condensed update of the IL-1 family of cytokines and receptors.

Predictors of Mortality in Acute Kidney Injury Patients Admitted to Medicine Intensive Care Unit in a Rural Tertiary Care Hospital

Background:

Acute kidney injury (AKI) is a challenging problem faced by intensive care clinicians worldwide, and it is associated with high morbidity and mortality, especially in critically ill patients.

Materials and Methods:

A hospital-based prospective, observational study was conducted in patients of AKI admitted to the Intensive Care Unit (ICU) of the Department of Medicine in a rural tertiary care hospital located in central India. Data of all consecutive AKI inpatients related to demographic variables, clinical profile, and laboratory investigations were collected from patient's medical records.

Results:

Of the total 229 AKI patients enrolled in this study, 65 (28.4%) patients died during their hospital stay. The presence of metabolic acidosis, hypotension, Glasgow coma scale (GCS) and Acute Physiologic Assesment and Chronic Health Evaluation (APACHE 2) score, advanced AKI stage, higher serum creatinine and blood urea levels on diagnosis of AKI and the peak rise in their level within 48 h of diagnosis of AKI, the use of mechanical ventilator, leukocytosis, and hyperkalemia were significantly associated with in-hospital mortality in AKI patients (P < 0.05).

Conclusion:

The overall in-hospital mortality in patients of AKI admitted to medicine-ICU was 28.4%. Sepsis was the most common cause of AKI (24.5%). The presence of metabolic acidosis, hypotension, GCS and APACHE 2 score, advanced AKI stage, higher serum creatinine, and blood urea levels on diagnosis of AKI and the peak rise in their level within 48 h of diagnosis of AKI, use of mechanical ventilator, leukocytosis, and hyperkalemia were associated with in-hospital mortality in AKI patients.

Biomarkers upon discontinuation of renal replacement therapy predict 60-day survival and renal recovery in critically ill patients with acute kidney injury

INTRODUCTION

There is no consensus on the specific indications for weaning critically ill patients with acute kidney injury (AKI) off renal replacement therapy (RRT). This study aimed to explore the prognostic value of several biomarkers measured upon discontinuation of RRT for their value in predicting 60-day survival and renal recovery in an effort to add knowledge to the decision-making process regarding RRT withdrawal.

METHODS

We prospectively enrolled 102 patients with AKI who required RRT from the intensive care unit. Serum osteopontin (sOPN), serum interleukin 6 (sIL-6), serum cystatin C (sCysC), sIL-18, serum neutrophil gelatinase-associated lipocalin and urinary IL-18 and urinary neutrophil gelatinase-associated lipocalin were measured upon discontinuation of RRT. Patients were followed up at 60 days for survival and renal recovery.

FINDINGS

Patients who survived showed lower levels of all serum and urinary biomarkers. Serum OPN (OR 1.029, 95% CI 1.013-1.047, P = 0.001), diabetes (OR 23.157, 95% CI 4.507-118.981, P < 0.001) and APACHE II score (OR 1.308, 95% CI 1.121-1.527, P = 0.001) were independent predictors of 60-day mortality. Patients whose sOPN values fell within the highest and middle tertiles showed 5.25- and 2.31-fold increased risks of mortality, respectively, compared with that of patients in the lowest tertile. The addition of sOPN to the clinical model resulted in significant net reclassification improvement of 0.453 (P = 0.026) and an integrated discriminative index of 0.155 (P = 0.032). Lower levels of sOPN and sIL-6 were associated with greater odds of 60-day survival (AUC 0.812 and 0.741). The AUC value for predicting survival reached its highest level when all biomarkers were combined with urine output (UO) and urinary and serum creatinine upon discontinuation of RRT (0.882). Lower sCysC performed as well as higher UO in predicting 60-day renal recovery with the greatest AUC of 0.743.

DISCUSSION

Upon discontinuation of RRT, serum and urinary biomarkers, particularly sOPN, may predict 60-day survival and renal recovery in critically ill patients with AKI. The serum levels of OPN, IL-6 and CysC may be useful when considering withdrawal of RRT on the basis of conventional indicators.

Using acute kidney injury severity and scoring systems to predict outcome in patients with burn injury

BACKGROUND/PURPOSE

Acute kidney injury (AKI) is a frequent complication of severe burn injury and is associated with mortality. The definition of AKI was modified by the Kidney Disease Improving Global Outcomes Group in 2012. So far, no study has compared the outcome accuracy of the new AKI staging guidelines with that of the complex score system. Hence, we compared the accuracy of these approaches in predicting mortality.

METHODS

This was a post hoc analysis of prospectively collected data from an intensive care burn unit in a tertiary care university hospital. Patients admitted to this unit from July 2004 to December 2006 were enrolled. Demographic, clinical, and laboratory data and prognostic risk scores were used as predictors of mortality.

RESULTS

A total of 145 adult patients with a mean age of 41.9 years were studied. Thirty-five patients (24.1%) died during the hospital course. Among the prognostic risk models, the Acute Physiology and Chronic Health Evaluation III system exhibited the strongest discriminative power and the AKI staging system also predicted mortality well (areas under the receiver operating characteristic curve: 0.889 vs. 0.835). Multivariate logistic regression analysis identified total burn surface area, ventilator use, AKI, and toxic epidermal necrolysis as independent risk factors for mortality.

CONCLUSION

Our results revealed that AKI stage has considerable discriminative power for predicting mortality. Compared with other prognostic models, AKI stage is easier to use to assess outcome in patients with severe burn injury.

Inflammatory Cytokines as Risk Factors for Mortality After Acute Cardiac Events

INTRODUCTION

Inflammatory markers have been identified as potential indicators of future adverse outcome after acute cardiac events.

AIM

This study aimed to analyze baseline inflammatory cytokines levels in patients with acute heart failure (AHF) and/or acute coronary syndrome (ACS) according to survival. The main objective was to identify risk factors for mortality after an episode of AHF and/or ACS.

METHODS

In this prospective longitudinal study 75 patients with the diagnosis of AHF and/or ACS were enrolled. Baseline laboratory and clinical data were retrieved. Serum and urine interleukin-6 (IL-6) and interleukin-18 (IL-18) levels, plasma B-type natriuretic peptide (BNP) and serum cystatin C values were determined. The primary outcome was in-hospital mortality while secondary outcome was six-month mortality.

RESULTS

Median serum and urine IL-6 levels, serum and urine IL-18 levels, as well as median concentrations of plasma BNP and serum cystatin C, were significantly increased in deceased in comparison to surviving AHF and/or ACS patients. Univariate Cox regression analysis identified serum IL-6, serum IL-18, urine IL-6, urine IL-18 as well as serum cystatin C and Acute Physiology and Chronic Health Evaluation (APACHE) II score as risk factors for mortality after an episode of AHF and/or ACS. Multivariate Cox regression analysis revealed that only serum IL-6 is the independent risk factor for mortality after acute cardiac events (HR 61.7, 95% CI 2.1-1851.0; p=0.018).

CONCLUSION

Present study demonstrated the strong prognostic value of serum IL-6 in predicting mortality of patients with AHF and/or ACS.

Elevation of Interleukin-18 Correlates With Cardiovascular, Cerebrovascular, and Peripheral Vascular Events: A Cohort Study of Hemodialysis Patients

Cardiocerebral vascular events are the major cause of mortality among patients with end-stage renal disease (ESRD). Subclinical inflammation and atherosclerosis have been implicated in the pathophysiology of ESRD. Evidence has shown the crucial role of interleukin-18 (IL-18) in inflammation. Interleukin-18 has been markedly upregulated in ESRD patients. Nevertheless, the ability of the IL-18 level to predict cardiocerebral vascular events and the correlation between IL-18 levels and cardiocerebral vascular events have not been established in hemodialysis patients.To determine whether the serum IL-18 level predicts cardiocerebral vascular events, the authors studied 171 ESRD patients. Samples were collected and patients were followed for 24 months. Demographic data, the duration of hemodialysis, nutrition status, inflammatory parameters, dialysis adequacy, and lipid profiles were analyzed to predict the outcome by using multivariate logistic regression. Cutoff points were calculated by acquiring the highest Youden index. The Kaplan-Meier method was used to scrutinize the cumulative proportion of events.The multivariate logistic regression model revealed that serum creatinine, C-reactive protein, and IL-18 levels were independent predictors for cardiocerebral vascular events. The odds ratio of events for each increase in IL-18 (pg/mL) was 1.008 for cardiocerebral vascular events. The area under the receiver operating characteristic curve of IL-18 was 0.779 ± 0.039, the overall correctness was 73%, and the Youden index was highest at a cutoff of 463 pg/mL. In the Kaplan-Meier model, patients with an IL-18 level higher than 463 pg/mL exhibited the highest probability of experiencing an adverse event during the entire follow-up period.Increased serum IL-18 could be considered as a predictor of cardiocerebral vascular events in dialysis patients. It is noteworthy that various comorbidities might interfere the expression of IL-18; therefore, further validation study is required to incorporate IL-18 in clinical use.

Biomarkers in Acute Kidney Injury

Acute kidney injury (AKI) is a common and often lethal complication that is also associated with severe morbidity in hospitalized patients. During the last decade, the standardization of AKI diagnostic criteria has helped to facilitate several large-scale investigations of biomarkers of AKI. These studies have led to the international clinical implementation of several biomarkers of renal injury. This review summarizes the results of many of these multicenter investigations and discusses the clinical utility and interpretation of several of these new clinical tests. The merits of combining biomarkers of kidney function is also discussed.

Novel biomarkers of acute kidney injury: Evaluation and evidence in urologic surgery

Patients undergoing urologic surgery are at risk of acute kidney injury (AKI) and consequently long-term deterioration in renal function. AKI is further associated with significantly higher odds of perioperative complications, prolonged hospital stay, higher mortality and costs. Therefore, better awareness and detection of AKI, as well as identification of AKI determinants in the urological surgery setting is warranted to pre-empt and mitigate further deterioration of renal function in patients at special risk. New consensus criteria provide precise definitions of diagnosis and description of the severity of AKI. However, they rely on serum creatinine (SCr), which is known to be an inaccurate marker of early changes in renal function. Therefore, several new urinary and serum biomarkers promise to address the gap associated with the use of SCr. Novel biomarkers may complement SCr measurement or most likely improve the diagnostic accuracy of AKI when used in combinations. However, novel biomarkers have to prove their clinical applicability, accuracy, and cost effectiveness prior to implementation into clinical practice. Most preferably, novel biomarkers should help to positively improve a patient’s long-term renal functional outcomes. The purpose of this review is to discuss currently available biomarkers and to review their clinical evidence within urologic surgery settings.

Acute kidney injury in adults receiving extracorporeal membrane oxygenation

Extracorporeal membrane oxygenation (ECMO) has been utilized for critically ill patients such as patients with postcardiotomy cardiogenic shock or life-threatening respiratory failure. Acute kidney injury (AKI) that develops during ECMO is associated with a very poor outcome, possibly because of accumulated extravascular water causing interstitial overload, impaired oxygen transport through tissues, and increased extravascular lung water volume with impaired O(2) transport. Increased water is associated with subsequent organ dysfunction, particularly of the heart, lungs, and brain. Based on single-center studies, the incidence of AKI is 70-85% in ECMO patients. Therefore, renal replacement therapy is required in approximately 50% of these patients. This review summarizes three modalities that can be used to introduce renal replacement therapy to patients on ECMO, the pathophysiology of AKI in ECMO, and the impact of AKI on mortality. This review also identifies specific research-focused questions that need to be addressed to predict AKI early and to improve outcomes in this at-risk adult population.

Role of TLR4 in lipopolysaccharide-induced acute kidney injury: protection by blueberry

Inflammation has been implicated in the pathophysiology of kidney disorders. Previous studies have documented the contributions of various inflammatory cascades in the development of kidney and other organ dysfunctions. The Toll-like receptor 4 (TLR4) inflammatory pathway is a major contributor of inflammation in the kidney. Interestingly, lipopolysaccharide (LPS), a specific ligand for TLR4, has been shown to induce acute kidney injury (AKI) in animal models. We have previously studied the beneficial effects of nonpharmacological agents, particularly blueberries (BB), in attenuating inflammation and oxidative stress. We hypothesize that BB protect against the LPS-induced AKI by inhibiting TLR4 activation and kidney injury markers. Twelve-week-old male Sprague-Dawley rats received a BB solution or saline intragastric gavage for 2 days. One group of BB and saline-gavaged animals was injected with LPS (10 mg/kg bw). Another group of rats was injected with VIPER (0.1 mg/kg iv), a TLR4-specific inhibitory peptide, 2 h before LPS administration. Compared to LPS-administered rats, the BB-pretreated animals exhibited improved glomerular filtration rate, elevated renal blood flow, and a reduced renal vascular resistance. In addition, a reduction in the rate of production of free radicals, namely total reactive oxygen species (ROS) and superoxide, was observed in the BB-supplemented LPS group. Gene and protein expressions for TLR4, proinflammatory cytokine, and acute kidney injury markers were also attenuated in animals that were pretreated with BB as measured by real time RT-PCR and Western blotting, respectively. These results in the BB-pretreated group were consistent with those in the VIPER-treated rats, and indicate that BB protects against AKI by inhibiting TLR4 and its subsequent effect on inflammatory and oxidative stress pathways.

[Definition and biomarkers of acute renal damage: new perspectives]

The RIFLE and AKIN criteria have definitely help out to draw attention to the relationship between a deterioration of renal function that produces a small increase in serum creatinine and a worse outcome. However, the specific clinical utility of using these criteria remains to be well-defined. It is believed that the main use of these criteria is for the design of epidemiological studies and clinical trials to define inclusion criteria and objectives of an intervention. AKI adopting term, re-summoning former ARF terminology, it is appropriate to describe the clinical condition characterized by damage to kidney, in the same way as the term is used to describe acute lung damage where the lung injury situation still has not increased to a situation of organ failure (dysfunction). The serum and urine biomarkers (creatinine, urea, and diuresis) currently in use are not sensitive or specific for detecting kidney damage, limiting treatment options and potentially compromising the outcome. New biomarkers are being studied in order to diagnose an earlier and more specific AKI, with the potential to change the definition criteria of AKI with different stages, currently based in diuresis and serum creatinine.

Plasma inflammatory and apoptosis markers are associated with dialysis dependence and death among critically ill patients receiving renal replacement therapy

BACKGROUND

Survivors of critical illness complicated by acute kidney injury requiring renal replacement therapy (RRT) are at an increased risk of dialysis dependence and death but the mechanisms are unknown.

METHODS

In a multicenter, prospective, cohort study of 817 critically ill patients receiving RRT, we examined association between Day 1 plasma inflammatory [interleukin (IL)-1β, IL-6, IL-8, IL-10 and IL-18; macrophage migration inhibitory factor (MIF) and tumor necrosis factor]; apoptosis [tumor necrosis factor receptor (TNFR)-I and TNFR-II and death receptor (DR)-5]; and growth factor (granulocyte macrophage colony stimulating factor) biomarkers and renal recovery and mortality at Day 60. Renal recovery was defined as alive and RRT independent.

RESULTS

Of 817 participants, 36.5% were RRT independent and 50.8% died. After adjusting for differences in demographics, comorbid conditions; premorbid creatinine; nephrotoxins; sepsis; oliguria; mechanical ventilation; RRT dosing; and severity of illness, increased concentrations of plasma IL-8 and IL-18 and TNFR-I were independently associated with slower renal recovery [adjusted hazard ratio (AHR) range for all markers, 0.70-0.87]. Higher concentrations of IL-6, IL-8, IL-10 and IL-18; MIF; TNFR-I and DR-5 were associated with mortality (AHR range, 1.16-1.47). In an analysis of multiple markers simultaneously, increased IL-8 [AHR, 0.80, 95% confidence interval (95% CI) 0.70-0.91, P < 0.001] and TNFR-I (AHR, 0.63, 95% CI 0.50-0.79, P < 0.001) were associated with slower recovery, and increased IL-8 (AHR, 1.26, 95% CI 1.14-1.39, P < 0.001); MIF (AHR, 1.18, 95% CI 1.08-1.28, P < 0.001) and TNFR-I (AHR, 1.26, 95% CI 1.02-1.56, P < 0.03) were associated with mortality.

CONCLUSIONS

Elevated plasma concentrations of inflammatory and apoptosis biomarkers are associated with RRT dependence and death. Our data suggest that future interventions should investigate broad-spectrum immune-modulation to improve outcomes.