Gastrointestinal disorders of the critically ill. Cholestasis of sepsis

Cholangitis Lenta: What Hepatologists Need to Know

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Tracking Modified Vaccinia Virus Ankara in the Chicken Embryo: In Vivo Tropism and Pathogenesis of Egg Infections

The Modified Vaccinia virus Ankara (MVA) is a highly attenuated vaccinia virus serving as a promising vector vaccine platform to develop vaccines against infectious diseases. In contrast to the well-established replication deficiency and safety of MVA in mammals, much less is known about MVA infection in avian hosts. Here, we used a recombinant MVA expressing fluorescent reporter proteins under transcriptional control of specific viral early and late promoters to study in vivo tropism, distribution, and pathogenesis of MVA infections in embryonated chicken eggs. The chorioallantoic membrane (CAM) of embryonated chicken eggs was inoculated with recombinant MVA, MVA or phosphate-buffered saline. The infection was analyzed by fluorescence microscopy, histology, immunohistochemistry, and virus titration of embryonic tissues. After infection of the CAM, MVA spread to internal and external embryonic tissues with the liver as a major target organ. Macrophages and hematopoietic cells were identified as primary target cells of MVA infection and may be involved in virus spread. Increasing doses of MVA did not result in increased lesion severity or embryonic death. Despite MVA generalization to embryonic tissues, the CAM seems to be the major site of MVA replication. The absence of considerable organ lesions and MVA-associated mortality highlights an excellent safety profile of MVA in chicken hosts.

Prognostic value of biochemical liver parameters in neonatal sepsis-associated cholestasis

AIMS

The aim of the study was to evaluate the significance of total bilirubin, aspartate transaminase (AST), alanine transaminase and gamma-glutamyltransferase (GGT) for predicting outcome in sepsis-associated cholestasis.

METHODS

A retrospective cohort review of the hospital records was performed in 181 neonates admitted to the Neonatal Care Unit. A comparison was performed between subjects with low and high liver values based on cut-off values from ROC analysis. We defined poor prognosis to be when a subject had prolonged cholestasis of more than 3.5 months, developed severe sepsis, septic shock or had a fatal outcome.

RESULTS

The majority of the subjects were male (56%), preterm (56%) and had early onset sepsis (73%). The poor prognosis group had lower initial values of GGT compared with the good prognosis group (P = 0.003). Serum GGT (cut-off value of 85.5 U/L) and AST (cut-off value of 51 U/L) showed significant correlation with the outcome following multivariate analysis. The odds ratio (OR) of low GGT and high AST were OR 4.3 (95% CI:1.6 to 11.8) and OR 2.9 (95% CI:1.1 to 8), respectively, for poor prognosis. In subjects with normal AST values, those with low GGT value had relative risk of 2.52 (95% CI:1.4 to 3.5) for poorer prognosis compared with those with normal or high GGT.

CONCLUSION

Serum GGT and AST values can be used to predict the prognosis of patients with sepsis-associated cholestasis.

Hepatic failure-induced hypogonadism in a prostate cancer patient

Hypogonadism owing to systemic diseases in prostate cancer is rare. Here, we present a patient with metastatic prostate cancer to the pericardium who had low serum testosterone level due to hepatic failure. The patient had cardiac tamponade, and pericardiocentesis revealed sanguineous exudate. Cytology revealed adenocarcinoma. High serum prostate-specific antigen level of 244 ng/mL was detected. The patient experienced complications of stress gastric and duodenal ulcer perforation and underwent subtotal gastrectomy. Perioperative intra-abdominal inflammatory process caused subsequent cholestasis and hepatic dysfunction. Transrectal ultrasound-guided prostate biopsy confirmed prostate cancer. Hypogonadism and a gradual decline in prostate-specific antigen were detected without any hormone therapy. The patient died due to hepatic failure in the 12(th) postoperative week.

Pregnancy-associated liver disorders

Liver disorders associated with pregnancy include hyperemesis gravidarum (HG), intrahepatic cholestasis of pregnancy (ICP), preeclampsia, syndrome of hemolysis, elevated liver enzymes and low platelets (HELLP), and acute fatty liver of pregnancy (AFLP). These conditions are relatively common and unique to pregnancy and are more likely to occur at certain terms of gestation specific to each condition. They can be associated with significant maternal and fetal morbidity and mortality. Although managing such patients may be very challenging, spontaneous resolution of the disease occurs shortly after termination of the pregnancy, usually without hepatic sequellae. Early diagnosis and timely treatment is a key to therapeutic success. This article explores the clinical features, pathophysiology, and management of these disorders.

Hepatocellular transport in acquired cholestasis: new insights into functional, regulatory and therapeutic aspects

The recent overwhelming advances in molecular and cell biology have added enormously to our understanding of the physiological processes involved in bile formation and, by extension, to our comprehension of the consequences of their alteration in cholestatic hepatopathies. The present review addresses in detail this new information by summarizing a number of recent experimental findings on the structural, functional and regulatory aspects of hepatocellular transporter function in acquired cholestasis. This comprises (i) a short overview of the physiological mechanisms of bile secretion, including the nature of the transporters involved and their role in bile formation; (ii) the changes induced by nuclear receptors and hepatocyte-enriched transcription factors in the constitutive expression of hepatocellular transporters in cholestasis, either explaining the primary biliary failure or resulting from a secondary adaptive response; (iii) the post-transcriptional changes in transporter function and localization in cholestasis, including a description of the subcellular structures putatively engaged in the endocytic internalization of canalicular transporters and the involvement of signalling cascades in this effect; and (iv) a discussion on how this new information has contributed to the understanding of the mechanism by which anticholestatic agents exert their beneficial effects, or the manner in which it has helped the design of new successful therapeutic approaches to cholestatic liver diseases.

Intrahepatic cholestasis after liver transplantation

Biochemical cholestasis after liver transplantation is common and often has no clinical significance if biliary anastomosis strictures and leaks have been excluded. There is no agreed upon definition for severe cholestasis, but it is associated with a worse mortality. There has been little evaluation on risk factors, but these include cryoprecipitate and platelet transfusion intraoperatively, nonidentical blood group, suboptimal graft appearance, inpatient status before transplant, and bacteremia within the first month. Associated causes considered as early (<6 months) include ischemia-reperfusion injury, primary nonfunction, small-for-size graft syndrome, infection, drugs and acute cellular rejection. Late causes include hepatic artery thrombosis, chronic rejection, biliary complications, recurrent viral and cholestatic disease, and posttransplant lymphoproliferative disorder.

Diagnosis and management of cholestatic liver disease

Cholestasis (slowing of bile flow) may be acute or chronic and affect any age group. In infants and children the causes often are congenital or inherited and as a result of improved management some affected children now survive to adulthood. Although jaundice is a hallmark of cholestasis it may be absent, particularly in adults with chronic cholestatic liver disease most of whom are entirely asymptomatic. A detailed history and physical are crucial to the diagnosis and noninvasive radiologic tests (ultrasound, computerized tomography scan, and magnetic resonance cholangiography) greatly facilitate diagnosis, particularly when the cause is extrahepatic. Only if sufficient portal tracts (>10) are present on liver biopsy examination can this test reliably evaluate damage to the small bile ducts. Therapy should address both the cause and the consequences of retained bile acids within the liver, and diminished delivery of bile to the gastrointestinal tract. Therapies should address symptoms, mostly pruritus and prevention, particularly osteoporosis and osteomalacia. Portal hypertension can be an early event in chronic cholestatic liver disease, sometimes occurring before the development of cirrhosis. Ursodeoxycholic acid improves the biochemical markers of cholestasis regardless of cause and may delay liver disease progression; only liver transplant is potentially curative.

Jaundice in critical illness: promoting factors of a concealed reality

OBJECTIVE

In critical illness, liver dysfunction (LD) is associated with a poor outcome independently of other organ dysfunctions. Since strategies to support liver function are not available, a timely and accurate identification of factors promoting LD may lead to prevention or attenuation of its consequences. The aim of this study was to assess risk factors for LD in critically ill patients.

DESIGN

Prospective, observational study.

SETTING

A multidisciplinary intensive care unit (ICU) of a university hospital.

PATIENTS

All patients consecutively admitted over a 6-month period.

INTERVENTION

None.

MEASUREMENTS AND RESULTS

LD was defined as serum bilirubin levels >or=2 mg/dl and lasting for at least 48 h. Out of 283 patients, 141 matched inclusion criteria. Forty-four patients (31.2%) showed LD (LD group), while 97 (68.8%) were included in control group (C group). A binomial analysis showed that LD occurrence was associated with moderate (odds ratio [OR] 3.11; p=0.04) and severe shock (OR 3.46; p= 0.05), sepsis (OR 3.03; p=0.04), PEEP ventilation (OR 4.25; p=0.006), major surgery (OR 4.03; p=0.03), and gram-negative infections (OR 3.94; p=0.002). In stepwise multivariate analysis, the single independent predictive factors of LD resulted in severe shock (p=0.002), sepsis (p=0.03), PEEP ventilation (p=0.04), and major surgery (p=0.05).

CONCLUSIONS

In critically ill patients jaundice is common, and severe shock states, sepsis, mechanical ventilation with PEEP and major surgery are critical risk factors for its onset. Since there is no specific treatment, prompt resuscitation, treatment of sepsis and meticulous supportive care will likely reduce its incidence and severity.

Enteric microbial flora, bacterial overgrowth, and short-bowel syndrome

Small intestinal bacterial overgrowth (SIBO) occurs commonly in short-bowel syndrome (SBS) and, in some instances, may result in significant problems. SIBO is characterized by a variety of signs and symptoms resulting from nutrient malabsorption caused by an increased number and/or type of bacteria in the small intestine. The anatomic and physiologic changes that occur in SBS together with medications commonly used in these patients facilitate the development of SIBO. Because many aspects related to SIBO in the SBS population remain poorly understood, it was our aim to review the current understanding of the gut flora and issues related to SIBO occurring in SBS.

Cholestatic syndromes

PURPOSE OF REVIEW

This review highlights recent developments in the molecular pathogenesis of cholestasis as well new aspects of pathogenesis and management of clinical cholestatic disorders.

RECENT FINDINGS

Highlights include the role of nuclear receptors including FXR ligands as potential therapeutic agents, new genetic defects for pediatric cholestasis and sclerosing cholangitis, and novel infections and environmental agents as etiologies for primary biliary cirrhosis. Important clinical studies have been published in the area of pediatric cholestatic syndromes, intrahepatic cholestasis of pregnancy, primary biliary cirrhosis, primary and secondary sclerosing cholangitis, cholestasis of sepsis, viral cholestatic syndromes, and drug-induced cholestasis.

SUMMARY

These advances continue to improve understanding of the pathophysiology, diagnosis, and management of cholestatic liver disease.