Renal Replacement Therapy in Cirrhosis: A Contemporary Review.

Acute kidney injury is a common complication of decompensated cirrhosis, frequently requires hospitalization, and carries a high short-term mortality. This population experiences several characteristic types of acute kidney injury: hypovolemic-mediated (prerenal), ischemic/nephrotoxic-mediated (acute-tubular necrosis), and hepatorenal syndrome. Prerenal acute kidney injury is treated with volume resuscitation. Acute-tubular necrosis is treated by optimizing perfusion pressure and discontinuing the offending agent. Hepatorenal syndrome, a unique physiology of decreased effective arterial circulation leading to renal vasoconstriction and ultimately acute kidney injury, is treated with plasma expansion with albumin and splanchnic vasoconstrictors such as terlipressin or norepinephrine. Common acute stressors such as bleeding, infection, and volume depletion often contribute to multifactorial acute kidney injury. Even with optimal medical management, many clinicians are faced with the challenge of initiating renal replacement therapy in these patients. This article reviews the epidemiology, indications, and complex considerations of renal replacement therapy for acute kidney injury in decompensated cirrhosis.

Healthcare Resource Utilization and Goals of Care Discussions in Patients with Cirrhosis and Acute Kidney Injury.

BACKGROUND: Patients with cirrhosis and acute kidney injury (AKI) are critically ill and have high health care resource utilization (HCRU). The impact and timing of goals of care discussions on HCRU are not well described. METHODS: 221 patients enrolled in a prospective cohort study of patients admitted with AKI and cirrhosis were reviewed. Documentation and timing of a goals of care discussions were analyzed as predictors of HCRU, defined as a composite outcome of intubation, initiation of renal replacement therapy, and/or admission to the intensive care unit. RESULTS: Median MELD score was 26 [IQR 19, 33]. 29% patients were listed for liver transplant. 90-day mortality was 61%. 51% patients had at least one HCRU episode. Code status changed from admission to discharge from 91%/7%/0% to 68%/14%18% (full code/do not resuscitate/comfort measures, p < 0.001). 28% patients underwent goals of care discussions, with change in code status at a median of 16 [9, 22] days into admission. Only 18% of discussions were within 7 days of admission and all were after an HCRU event. Being listed for liver transplant was not associated with whether goals of care discussions occurred (23% listed vs. 31% non-listed, p = 0.24) but was associated with higher HCRU (69% vs. 43%; p < 0.001). CONCLUSION: Goals of care discussions occurred late into the hospital course, after episodes of HCRU. Efforts should be made to engage in these discussions earlier in the hospital stay, which may decrease HCRU rates in this critically ill population and align with patients' goals of care.

Urinary NGAL as a Diagnostic and Prognostic Marker for Acute Kidney Injury in Cirrhosis: A Prospective Study.

INTRODUCTION: Urinary neutrophil gelatinase-associated lipocalin (NGAL) has shown promise in differentiating acute tubular necrosis (ATN) from other types of acute kidney injuries (AKIs) in cirrhosis, particularly hepatorenal syndrome (HRS). However, NGAL is not currently available in clinical practice in North America. METHODS: Urinary NGAL was measured in a prospective cohort of 213 US hospitalized patients with decompensated cirrhosis (161 with AKI and 52 reference patients without AKI). NGAL was assessed for its ability to discriminate ATN from non-ATN AKI and to predict 90-day outcomes. RESULTS: Among patients with AKI, 57 (35%) had prerenal AKI, 55 (34%) had HRS, and 49 (30%) had ATN, with a median serum creatinine of 2.0 (interquartile range 1.5, 3.0) mg/dL at enrollment. At an optimal cutpoint of 244 µg/g creatinine, NGAL distinguished ATN (344 [132, 1,429] µg/g creatinine) from prerenal AKI (45 [0, 154] µg/g) or HRS (110 [50, 393] µg/g; P < 0.001), with a C statistic of 0.762 (95% confidence interval 0.682, 0.842). By 90 days, 71 of 213 patients (33%) died. Higher median NGAL was associated with death (159 [50, 865] vs 58 [0, 191] µg/g; P < 0.001). In adjusted and unadjusted analysis, NGAL significantly predicted 90-day transplant-free survival (P < 0.05 for all Cox models) and outperformed Model for End-Stage Liver Disease score by C statistic (0.697 vs 0.686; P = 0.04), net reclassification index (37%; P = 0.008), and integrated discrimination increment (2.7%; P = 0.02). DISCUSSION: NGAL differentiates the type of AKI in cirrhosis and may improve prediction of mortality; therefore, it holds potential to affect management of AKI in cirrhosis.

Desymmetrization of Diols by Phosphorylation with a Titanium-BINOLate Catalyst.

The desymmetrization of ten prochiral diols by phosphoryl transfer with a titanium-BINOLate complex is discussed. The phosphorylation of nine 1,3-propane diols is achieved in yields of 50-98%. Enantiomeric ratios as high as 92:8 are achieved with diols containing a quaternary C-2 center incorporating a protected amine. The chiral ligand, base, solvent, and stoichiometry are evaluated along with a nonlinear effect study to support an active catalyst species that is oligomeric in chiral ligand. The use of pyrophosphates as the phosphorylating agent in the desymmetrization facilitates a user-friendly method for enantioselective phosphorylation with desirable protecting groups (benzyl, o-nitrobenzyl) on the phosphate product.

Filter clotting with continuous renal replacement therapy in COVID-19.

Coronavirus disease 2019 (COVID-19) appears to be associated with increased arterial and venous thromboembolic disease. These presumed abnormalities in hemostasis have been associated with filter clotting during continuous renal replacement therapy (CRRT). We aimed to characterize the burden of CRRT filter clotting in COVID-19 infection and to describe a CRRT anticoagulation protocol that used anti-factor Xa levels for systemic heparin dosing. Multi-center study of consecutive patients with COVID-19 receiving CRRT. Primary outcome was CRRT filter loss. Sixty-five patients were analyzed, including 17 using an anti-factor Xa protocol to guide systemic heparin dosing. Fifty-four out of 65 patients (83%) lost at least one filter. Median first filter survival time was 6.5 [2.5, 33.5] h. There was no difference in first or second filter loss between the anti-Xa protocol and standard of care anticoagulation groups, however fewer patients lost their third filter in the protocolized group (55% vs. 93%) resulting in a longer median third filter survival time (24 [15.1, 54.2] vs. 17.3 [9.5, 35.1] h, p = 0.04). The rate of CRRT filter loss is high in COVID-19 infection. An anticoagulation protocol using systemic unfractionated heparin, dosed by anti-factor Xa levels is reasonable approach to anticoagulation in this population.

Accelerated Venovenous Hemofiltration as a Transitional Renal Replacement Therapy in the Intensive Care Unit.

BACKGROUND: Continuous renal replacement therapy (CRRT) is commonly employed in the intensive care unit (ICU), though there are no guidelines around the transition between CRRT and intermittent hemodialysis (iHD). Accelerated venovenous hemofiltration (AVVH) is a modality utilizing higher hemofiltration rates (4-5 L/h) with shorter session durations (8-10 h) to "accelerate" the clearance and volume removal that normally is spread out over a 24-h period in CRRT. We examined AVVH as a transition therapy between CRRT and iHD, with the aim of decreasing time on CRRT and providing a more graduated transition for hemodynamically unstable patients requiring RRT. METHODS: Retrospective cohort study describing the clinical outcomes and quality initiative experience of the integration of AVVH into the CRRT program at an academic tertiary care center. Outcomes of interest included mortality, ICU length of stay and readmission rates, and technical characteristics of treatments. RESULTS: In total, 97 patients received a total of 298 AVVH treatments (3.1 ± 3.3 treatments per patient). Totally, 271/298 (91%) treatments were completed successfully. During an average treatment time of 9.5 ± 1.6 h with 4.2 ± 0.5 L/h -replacement fluid rate, urea reduction ratio was 23 ± 26% per 10-h treatment, and net ultrafiltration volume was 2.4 ± 1.3 L/treatment. Inpatient mortality was 32%, mean total hospital length of stay was 54 ± 47 days. Sixty-four out of 97 (66%) patients recovered renal function by discharge. Among those who transferred out of the ICU, 7/62 (11%) patients required readmission to the ICU after developing hypotension on iHD. CONCLUSION: AVVH can serve as a transition therapy between CRRT and iHD in the ICU and has the potential to decrease total time on CRRT, improve patient mobility, and sustain low ICU readmission rates. Future study is needed to analyze the implications on resource use and cost of this modality.

Crohn's disease: failure of a proprietary fluorescent in situ hybridization assay to detect M. avium subspecies paratuberculosis in archived frozen intestine from patients with Crohn's disease.

OBJECTIVES: Although controversial, there is increasing concern that Crohn's disease may be a zoonotic infectious disease consequent to a mycobacterial infection. The most plausible candidate is M. avium subspecies paratuberculosis (MAP) that is unequivocally responsible for Johne's disease in ruminants. The purpose of this study was to evaluate a proprietary (Affymetrix™ RNA view®) fluorescent in situ hybridization (FISH) assay for MAP RNA. Non-identifiable intestine from patients with documented Crohn's disease was assayed according to the manufacturer's instructions and with suggested modifications. Probes were custom designed for MAP and human ß-actin (as the eukaryotic housekeeping gene) from published genomes. RESULTS: Repetitively, false positive signal was observed in our "No-Probe" negative control. Attempts were made to correct this according to the manufacturer's suggestions (by modifying wash solutions, using recommended hydrochloric acid titration and different fluorescent filters). None prevented false positive signal in the "No-Probe" control. It is concluded that when performed according to manufactures instruction and with multiple variations on the manufactures recommended suggestions to correct for false positive signal, that the Affymetrix™ RNA view® cannot be used to detect MAP in pre-frozen resected intestine of humans with Crohn's disease.

Positron emission tomography as an adjuvant diagnostic test in the evaluation of checkpoint inhibitor-associated acute interstitial nephritis.

BACKGROUND: Acute interstitial nephritis is an immune-related adverse event that can occur in patients receiving immune checkpoint inhibitor therapy. Differentiating checkpoint inhibitor-associated acute interstitial nephritis from other causes of acute kidney injury in patients with cancer is challenging and can lead to diagnostic delays and/or unwarranted immunosuppression. In this case report, we assess the use of 18F-flourodeoxyglucose positron-emission tomography imaging as an alternative diagnostic modality in the evaluation of potential acute interstitial nephritis. CASE PRESENTATION: A 55-year-old woman with metastatic vulvar melanoma underwent treatment with two cycles of ipilimumab plus nivolumab, followed by seven cycles of nivolumab combined with radiation therapy. During her treatment, she developed non-oliguric acute kidney injury to a creatinine of 4.5 mg/dL from a baseline of 0.5 mg/dL. A clinical diagnosis of acute interstitial nephritis was made, and steroids were initiated, with rapid improvement of her acute kidney injury. Retrospectively, four positron-emission tomography scans obtained for cancer staging purposes were reviewed. We found a markedly increased 18F-flourodeoxyglucose uptake in the renal cortex at the time acute interstitial nephritis was diagnosed compared to baseline. In three cases of acute kidney injury due to alternative causes there was no increase in 18F-flourodeoxyglucose uptake from baseline. CONCLUSIONS: To our knowledge, this is the first report describing increased 18F-flourodeoxyglucose uptake in the renal cortex in a patient with checkpoint inhibitor-associated acute interstitial nephritis. Our findings suggest that 18F-flourodeoxyglucose positron-emission tomography may be a valuable test for diagnosing immune-mediated nephritis, particularly in patients where timely kidney biopsy is not feasible.

Evaluation of model performance to predict survival after transjugular intrahepatic portosystemic shunt placement.

BACKGROUND/AIMS: The MELD score was developed to predict survival after transjugular intrahepatic portosystemic shunt (TIPS) placement. Given changes in practice patterns and development of new prognostic tools in cirrhosis, we aimed to evaluate common models to predict mortality after TIPS placement. METHODS: Analysis of consecutive patients who underwent TIPS placement for ascites or bleeding. Performance to predict 90-day mortality was assessed by C statistic for six models (MELD, MELD-Na, CLIF-C ACLF, Child-Pugh, Platelet-Albumin-Bilirubin, and Emory score). Added predictive value to MELD score was assessed for univariate predictors of 90-day mortality. Stratified analysis by TIPS indication, emergent placement status, and TIPS stent type was performed. RESULTS: 413 patients were analyzed (248 with variceal bleeding, 165 with refractory ascites). 90-day mortality was 27% (113/413). Mean MELD score was 15 ± 7.9. MELD score best predicted mortality for all patients (c = 0.779), for variceal bleeding (c = 0.844), and for emergent TIPS (c = 0.817). CLIF-C ACLF score best predicted mortality for refractory ascites (c = 0.707). Addition of sodium to the MELD score did not improve predictive value across multiple strata. Addition of hemoglobin improved MELD score's predictive value in variceal bleeding. Addition of age improved MELD score's predictive value in refractory ascites. CONCLUSIONS: MELD score best predicted 90-day mortality. Addition of sodium to the MELD score did not improve its performance, though mortality prediction was improved using Age-MELD for ascites and Hemoglobin-MELD for bleeding. An individualized risk stratification approach may be best when considering candidates for TIPS placement.

Pancreatoblastoma: a rare tumor still evolving in clinical presentation and histology.

CONTEXT: Pancreatoblastoma is a rare neoplasm in adults with a total of only 24 cases that have been reported in the literature. Adult pancreatoblastomas are large tumors and majority are larger than 8 cm at the time of diagnosis. Metastasis is seen in 26% of adults and usually involves the liver and then the lymph nodes. Metastasis is usually observed in cases where the primary tumor measures more than 10 cm. Pancreatoblastoma is named after its resemblance to fetal pancreatic tissue in the seventh week of life. The presence of squamoid corpuscles with a morular appearance is the most characteristic feature of the tumor. Pancreatoblastomas can have mixed features of both endocrine and exocrine cells; however, acinar differentiation is the most prevalent feature. CASE REPORT: We present a case of a 27-year-old female with a 3.6 cm pancreatoblastoma with metastasis to the liver and lungs as well as to the breast. This case has several distinguishing features from previously reported cases. Such widespread metastasis is unusual given the small size of the primary tumor. Also, metastasis to the breast from a pancreatoblastoma has been previously undescribed in literature. The histological features in our case of pancreatoblastoma were atypical, characterized by the absence of acinar component, supported by the lack of staining for both trypsin and lipase in the tumor, which has not been described in literature. Additionally, the nests of squamous cells in this tumor had a pilomatricoma like morphology as opposed to the morular appearance of the squamoid corpuscles seen in classical cases. CONCLUSION: Pancreatoblastoma can have an atypical clinical picture and a small primary with extensive metastasis to unusual sites may present a diagnostic challenge. Given its rarity, a high index of suspicion is required to correctly diagnose this condition. The histology reported on this case is unique and has not been reported in the literature.

Urothelial metaplasia of the seminal vesicles: a report of 2 cases.

Although urothelial metaplasia has been reported in the fallopian tube, urothelium in the seminal vesicle has been rarely reported. We report 2 cases of urothelial epithelium in seminal vesicles from radical prostatectomy specimens. One case involved a 63-year-old patient with pT2c prostatic adenocarcinoma (Gleason pattern 3+4; total score, 7). The other case involved a 60-year-old patient with pT2c prostatic adenocarcinoma (Gleason pattern 4+3; total score, 7; with focal Gleason pattern 5). Representative sections of the left seminal vesicles from both patients demonstrated a portion of urothelial epithelium consisting of 3 to 8 cell layers, which included superficial (umbrella), intermediate, and basal cells. An abrupt transition from the normal single layer of cuboidal cells of seminal vesicle to multilayered urothelium was identified in 1 case, and circumferential urothelium was identified in the other case. No urothelial metaplasia was seen in the prostatic tissue. The histogenesis of urothelial metaplasia in the seminal vesicle is unclear, but it possibly is a reaction to mechanical irritation, inflammation, or infection, as has been proposed for urothelial metaplasia in the fallopian tube and squamous metaplasia of the pelvic peritoneum. Nevertheless, a rare congenital malformation cannot be ruled out as an etiology. Clinical follow-up of patients with urothelial cell metaplasia of the fimbriae suggests that it bears no biologic significance, yielding no instances of carcinoma. However, whether there will be an impact on fertility awaits further study.

Cell-permeable MR contrast agents with increased intracellular retention.

Magnetic resonance imaging (MRI) is a technique used in both clinical and experimental settings to produce high-resolution images of opaque organisms without ionizing radiation. Currently, MR imaging is augmented by contrast agents, and the vast majority these small molecule Gd(III) chelates are confined to the extracellular regions. As a result, contrast agents are confined to vascular regions reducing their ability to provide information about cell physiology or molecular pathology. We have shown that polypeptides of arginine have the capacity to transport Gd(III) contrast agents across cell membranes. However, this transport is not unidirectional, and once inside the cell, the arginine-modified contrast agents efflux rapidly, decreasing the intracellular Gd(III) concentration and corresponding MR image intensity. By exploiting the inherent disulfide reducing environment of cells, thiol compounds, Gd(III)-DOTA-SS-Arg 8 and Gd(III)-DTPA-SS-Arg 8, are cleaved from their cell-penetrating peptide transduction domains upon cell internalization. This reaction prolongs the cell-associated lifetime of the chelated Gd(III) by cleaving it from the cell transduction domain.

DNA-TiO2 nanoconjugates labeled with magnetic resonance contrast agents.

Recent efforts have shown that nanoscale materials, specifically, metal-based nanoparticles, hold particular promise for the development of multifunctional imaging probes. These new materials provide the means to chaperone and concentrate both drugs and contrast agents in specific organs, tissues, and cells. Therefore, we have prepared a Gd(III)-modified DNA-TiO2 semiconducting nanoparticle that is detectable in cells by MR imaging. These labeled particles are retained at specific subcellular locations via DNA hybridization to intracellular targets, hence creating the first nanoparticle system capable of targeting specific DNA sequences while being simultaneously detected via MR imaging.

Quantitative imaging of cell-permeable magnetic resonance contrast agents using x-ray fluorescence.

The inability to transduce cellular membranes is a limitation of current magnetic resonance imaging probes used in biologic and clinical settings. This constraint confines contrast agents to extracellular and vascular regions of the body, drastically reducing their viability for investigating processes and cycles in developmental biology. Conversely, a contrast agent with the ability to permeate cell membranes could be used in visualizing cell patterning, cell fate mapping, gene therapy, and, eventually, noninvasive cancer diagnosis. Therefore, we describe the synthesis and quantitative imaging of four contrast agents with the capability to cross cell membranes in sufficient quantity for detection. Each agent is based on the conjugation of a Gd(III) chelator with a cellular transduction moiety. Specifically, we coupled Gd(III)-diethylenetriaminepentaacetic acid DTPA and Gd(III)-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid with an 8-amino acid polyarginine oligomer and an amphipathic stilbene molecule, 4-amino-4'-(N,N-dimethylamino)stilbene. The imaging modality that provided the best sensitivity and spatial resolution for direct detection of the contrast agents is synchrotron radiation x-ray fluorescence (SR-XRF). Unlike optical microscopy, SR-XRF provides two-dimensional images with resolution 10(3) better than (153)Gd gamma counting, without altering the agent by organic fluorophore conjugation. The transduction efficiency of the intracellular agents was evaluated by T(1) analysis and inductively coupled plasma mass spectrometry to determine the efficacy of each chelate-transporter combination.