Accuracy of immunoassay and mass spectrometry urinary free cortisol in the diagnosis of Cushing's syndrome

PURPOSE

Urinary free cortisol (UFC) determination by highly specific methods as mass spectrometry instead of commercially available antibody-based immunoassays is increasingly recommended. However, clinical comparisons of both analytical approaches in the screening of Cushing's syndrome (CS) are not available. The aim of this study was to evaluate the diagnostic value of mass spectrometry versus immunoassay measurements of 24 h-UFC in the screening of CS.

METHODS

Cross-sectional study of 33 histologically confirmed CS patients: 25 Cushing's disease, 5 adrenal CS and 3 ectopic CS; 92 non-CS patients; and 35 healthy controls. UFC by immunoassay (UFCxIA) and mass spectrometry (UFCxMS), urinary free cortisone (UFCo) and UFC:UFCo ratio were measured, together with creatinine-corrected values. Sensitivity, specificity, AUC and Landis and Koch concordance index were determined.

RESULTS

AUC for UFCxIA and UFCxMS were 0.77 (CI 0.68-0.87) and 0.77 (CI 0.67-0.87) respectively, with a kappa coefficient 0.60 and strong Landis and Koch concordance index. The best calculated cutoff values were 359 nmol/24 h for UFCxIA (78 % sensitivity, 62 % specificity) and 258.1 nmol/24 h for UCFxMS (53 % sensitivity, 86 % specificity). The upper limit of UFCxIA and UCFxMS reference ranges were 344.7 and 169.5 nmol/24 h respectively. Sensitivity and specificity for CS diagnosis at these cutpoints were 84 and 56 % for UFCxIA and 81 and 54 % for UFCxMS.

CONCLUSIONS

According to our data, both methods present a very similar diagnostic value. However, results suggest that lower cutoff points for mass spectrometry may be necessary in order to improve clinical sensitivity.

Neutrophil gelatinase-associated lipocalin is a biomarker of acute-on-chronic liver failure and prognosis in cirrhosis

BACKGROUND & AIMS

Acute-on-chronic liver failure (ACLF) is a syndrome that occurs in cirrhosis characterized by organ failure(s) and high mortality rate. There are no biomarkers of ACLF. The LCN2 gene and its product, neutrophil gelatinase-associated lipocalin (NGAL), are upregulated in experimental models of liver injury and cultured hepatocytes as a result of injury by toxins or proinflammatory cytokines, particularly Interleukin-6. The aim of this study was to investigate whether NGAL could be a biomarker of ACLF and whether LCN2 gene may be upregulated in the liver in ACLF.

METHODS

We analyzed urine and plasma NGAL levels in 716 patients hospitalized for complications of cirrhosis, 148 with ACLF. LCN2 expression was assessed in liver biopsies from 29 additional patients with decompensated cirrhosis with and without ACLF.

RESULTS

Urine NGAL was markedly increased in ACLF vs. no ACLF patients (108(35-400) vs. 29(12-73)μg/g creatinine; p<0.001) and was an independent predictive factor of ACLF; the independent association persisted after adjustment for kidney function or exclusion of variables present in ACLF definition. Urine NGAL was also an independent predictive factor of 28day transplant-free mortality together with MELD score and leukocyte count (AUROC 0.88(0.83-0.92)). Urine NGAL improved significantly the accuracy of MELD in predicting prognosis. The LCN2 gene was markedly upregulated in the liver of patients with ACLF. Gene expression correlated directly with serum bilirubin and INR (r=0.79; p<0.001 and r=0.67; p<0.001), MELD (r=0.68; p<0.001) and Interleukin-6 (r=0.65; p<0.001).

CONCLUSIONS

NGAL is a biomarker of ACLF and prognosis and correlates with liver failure and systemic inflammation. There is remarkable overexpression of LCN2 gene in the liver in ACLF syndrome.

LAY SUMMARY

Urine NGAL is a biomarker of acute-on-chronic liver failure (ACLF). NGAL is a protein that may be expressed in several tissues in response to injury. The protein is filtered by the kidneys due to its small size and can be measured in the urine. Ariza, Graupera and colleagues found in a series of 716 patients with cirrhosis that urine NGAL was markedly increased in patients with ACLF and correlated with prognosis. Moreover, gene coding NGAL was markedly overexpressed in the liver tissue in ACLF.

Early non-invasive selection of patients at high risk of severe hepatitis C recurrence after liver transplantation

BACKGROUND

The early identification of patients at high risk of severe post liver transplant hepatitis C recurrence is relevant, as these patients may be treated using interferon (IFN)-free regimens.

METHODS

In a retrospective study with prospectively collected data, we investigated whether the use of several non-invasive methods (fibrosis 4 index [FIB-4], AST-to-platelets ratio index [APRI], enhanced liver fibrosis test [ELF], IFN-γ-inducible protein 10 [IP-10], and transient elastography by Fibroscan) and their combinations 6 months after transplantation could identify those recipients at higher risk of severe recurrence, defined by the presence of significant fibrosis (F ≥2) and/or portal hypertension (hepatic venous pressure gradient ≥6 mmHg) 12 months after transplant. Seventy-two hepatitis C virus (HCV)-infected liver transplant patients and 10 recipients in whom HCV was eradicated before transplantation were included in the study.

RESULTS

The levels of all biomarkers were significantly higher in HCV-infected recipients than in controls. Among HCV recipients, levels of biomarkers were significantly higher in patients with severe recurrence. Although there were no statistically significant differences between biomarkers, APRI, ELF, and FIB-4 obtained the highest area under the ROC curve values. The combination of serum biomarkers with Fibroscan increased the negative and positive predictive values, although diagnostic accuracy of individual tests was not significantly improved.

CONCLUSIONS

Patients at higher risk of severe HCV recurrence can be identified early, 6 months after transplantation, using readily available non-invasive methods.

Adenoviral dominant-negative soluble PDGFRβ improves hepatic collagen, systemic hemodynamics, and portal pressure in fibrotic rats

BACKGROUND & AIMS

Platelet-derived growth factor (PDGF) is the most potent stimulus for proliferation and migration of stellate cells. PDGF receptor β (PDGFRβ) expression is an important phenotypic change in myofibroblastic cells that mediates proliferation and chemotaxis. Here we analyzed the relationship between PDGFRβ expression, hemodynamic deterioration, and fibrosis in CCl(4)-treated rats. Thereafter, we investigated the effects produced by an adenovirus encoding a dominant-negative soluble PDGFRβ (sPDGFRβ) on hemodynamic parameters, PDGFRβ signaling pathway, and fibrosis.

METHODS

Mean arterial pressure, portal pressure, PDGFRβ mRNA expression, and hepatic collagen were assessed in 6 controls and 21 rats induced to hepatic fibrosis/cirrhosis. Next, 30 fibrotic rats were randomized into three groups receiving iv saline and an adenovirus encoding for sPDGFRβ or β-galactosidase. After 7days, mean arterial pressure, portal pressure, serum sPDGFRβ, and hepatic collagen were measured.

RESULTS

CCl(4)-treated animals for 18weeks showed a significantly higher increase in PDGFRβ mRNA compared to those treated for 13weeks and control rats. In CCl(4)-treated rats, the fibrous tissue area ranged from moderate to severe fibrosis. A direct relationship between the degree of fibrosis, hemodynamic changes, and PDGFRβ expression was observed. Fibrotic rats transduced with the adenovirus encoding sPDGFRβ showed increased mean arterial pressure, decreased portal pressure, lower activation of the PDGFRβ signaling pathway, and reduced hepatic collagen than fibrotic rats receiving β-galactosidase or saline.

CONCLUSIONS

PDGFRβ activation closely correlates with hemodynamic disorders and increased fibrosis in CCl(4)-treated rats. Adenoviral dominant negative soluble PDGFRβ improved fibrosis. As a result, the hemodynamic abnormalities were ameliorated.

Assessment of liver fibrosis before and after antiviral therapy by different serum marker panels in patients with chronic hepatitis C

BACKGROUND

Liver biopsy is the reference standard to assess liver fibrosis in chronic hepatitis C.

AIM

To validate and compare the diagnostic performance of non-invasive tests for prediction of liver fibrosis severity and assessed changes in extracellular matrix markers after antiviral treatment.

METHODS

The performances of Forns' score, AST to platelet ratio index (APRI), FIB-4 index and Enhanced Liver Fibrosis (ELF) score were validated in 340 patients who underwent antiviral therapy. These scores were determined 24 weeks after treatment in 161 patients.

RESULTS

Forns' score, APRI, FIB-4 and ELF score showed comparable diagnostic accuracies for significant fibrosis [area under the receiver operating characteristic curve (AUROC) 0.83, 0.83, 0.85 and 0.81, respectively]. To identify cirrhosis, FIB-4 index showed a significantly better performance over APRI and ELF score (AUROC 0.89 vs. 0.83 and 0.82, respectively). ELF score decreased significantly in patients with sustained virological response (SVR) (P < 0.0001) but remained unchanged in nonresponders. Non-1 hepatitis C virus (HCV) genotype, baseline lower HCV RNA, glucose, hyaluronic acid and higher cholesterol levels were independently associated with SVR.

CONCLUSIONS

Simple panel markers and ELF score are accurate at identifying significant fibrosis and cirrhosis in chronic hepatitis C. A decrease in ELF score after antiviral treatment reflects the impact of viral clearance in hepatic extracellular matrix and probably in the improvement of liver fibrosis.

Inactivation of extrahepatic vascular Akt improves systemic hemodynamics and sodium excretion in cirrhotic rats

BACKGROUND & AIMS

Increased activity of the vascular Akt/eNOS signaling pathway is involved in the hemodynamic and renal complications developed by patients and rats with cirrhosis and ascites. This occurs in the setting of impaired Akt/eNOS activity within the cirrhotic liver. Here we assessed the feasibility of selectively inhibiting vascular eNOS without further impairing the intrahepatic activity of this enzyme. Ultimately, we sought to determine whether endothelial transduction of a constitutively inactive mutant of Akt (AA-Akt) improves circulatory function and sodium excretion in cirrhotic rats with ascites.

METHODS

First, we administered recombinant adenoviruses that encode the β-galactosidase gene (β-gal) to 5 control rats and 5 cirrhotic rats with ascites and analyzed their tissue distribution by chemiluminescence. Next, urine samples were obtained from 18 cirrhotic rats with ascites and then the animal randomly received saline or adenoviruses containing the β-gal or the AA-Akt genes. Following a 24-h urine collection period, hemodynamic studies were performed and tissue samples were obtained to analyze Akt and eNOS expressions.

RESULTS

No β-gal activity was detected in the liver of cirrhotic rats compared to that of controls. This was paralleled by increased β-gal activity in other territories such as the thoracic aorta. AA-Akt transduction improved systemic hemodynamics, splanchnic perfusion pressure and renal excretory function in comparison with cirrhotic rats transduced with β-gal adenoviruses or receiving saline. Moreover, the AA-Akt transgene did not modify portal pressure.

CONCLUSIONS

Inactivation of extrahepatic vascular Akt and the concomitant decrease in nitric oxide expression ameliorate systemic hemodynamics and renal excretory function in experimental cirrhosis.

Vascular endothelial growth factor and angiopoietin-2 play a major role in the pathogenesis of vascular leakage in cirrhotic rats

BACKGROUND AND AIMS

The extent and molecular mechanisms governing plasma extravasation and formation of ascites in cirrhosis are unknown. Vascular endothelial growth factor-A (VEGF-A) and angiopoietin-2 (Ang-2) are endogenous substances with powerful vascular permeability effects. We assessed regional blood flow, vascular leakage, mRNA and tissular expression of VEGF-A and Ang-2 and vascular permeability following VEGF receptor 2 blockade in control and cirrhotic rats to define the vascular territories showing altered vascular permeability in cirrhosis and to determine whether VEGF-A and Ang-2 are involved in this phenomenon.

METHODS

Arterial blood flow was analysed with the coloured microsphere method. Vascular leakage was measured and visualised with the dye Evan's Blue and colloidal carbon techniques, respectively. VEGF-A and Ang-2 expression were determined by real-time polymerase chain reaction (RT-PCR), immunohistochemistry and western blot. The effect on vascular permeability induced by VEGFR(2) blockade was assessed by administration of the receptor inhibitor SU11248.

RESULTS

Arterial blood flow was increased in the mesentery, pancreas and small intestine but not in the kidney and spleen of cirrhotic rats as compared to controls. Increased vascular leakage was observed in the mesentery and liver, where colloidal carbon spread from microvessels to the adjacent fibrotic tracts. Increased hepatic and mesenteric expression of VEGF-A and Ang-2 was found in cirrhotic rats as compared to controls. Blockade of VEGFR(2) markedly reduced hepatic and mesenteric vascular leakage in cirrhotic rats.

CONCLUSIONS

Enhanced endothelial permeability is restricted to the hepatic and mesenteric vascular beds in cirrhotic rats with ascites and VEGF-A and Ang-2 are key factors in the signalling pathways regulating this dysfunction.

Gene transduction of an active mutant of akt exerts cytoprotection and reduces graft injury after liver transplantation

Akt is expected to be an effective target for the treatment of ischemia-reperfusion injury (I/R) due to its anti-apoptotic properties and its ability to activate the endothelial nitric oxide synthase (eNOS) enzyme. Therefore, this study was aimed to determine the efficacy of an active mutant of Akt (myr-Akt) to decrease I/R injury in a model of orthotopic liver transplantation in pigs. In addition, we analyzed the contribution of nitric oxide in the Akt-mediated effects by using an eNOS mutant (S1179DeNOS) that mimics the phosphorylation promoted by Akt in the eNOS sequence. Donors were treated with adenoviruses codifying for myr-Akt, S1179DeNOS or beta-galactosidase 24 h before liver harvesting. Then, liver grafts were orthotopically transplanted into their corresponding recipients. Levels of transaminases and lactate dehydrogenase (LDH) increased in all recipients after 24 h of transplant. However, transaminases and LDH levels were significantly lower in the myr-Akt group compared with vehicle. The percentage of apoptotic cells and the amount of activated-caspase 3 protein were also markedly reduced in myr-Akt-treated grafts after 4 days of liver transplant compared with vehicle and S1179DeNOS groups. In conclusion, myr-Akt gene therapy effectively exerts cytoprotection against hepatic I/R injury regardless of the Akt-dependent eNOS activation.

Increased anandamide induced relaxation in mesenteric arteries of cirrhotic rats: role of cannabinoid and vanilloid receptors

BACKGROUND AND AIMS

Anandamide is an endocannabinoid that evokes hypotension by interaction with peripheral cannabinoid CB1 receptors and with the perivascular transient receptor potential vanilloid type 1 protein (TRPV1). As anandamide has been implicated in the vasodilated state in advanced cirrhosis, the study investigated whether the mesenteric bed from cirrhotic rats has an altered and selective vasodilator response to anandamide.

METHODS

We assessed vascular sensitivity to anandamide, mRNA and protein expression of cannabinoid CB1 receptor and TRPV1 receptor, and the topographical distribution of cannabinoid CB1 receptors in resistance mesenteric arteries of cirrhotic and control rats.

RESULTS

Mesenteric vessels of cirrhotic animals displayed greater sensitivity to anandamide than control vessels. This vasodilator response was reverted by CB1 or TRPV1 receptor blockade, but not after endothelium denudation or nitric oxide inhibition. Anandamide had no effect on distal femoral arteries. CB1 and TRPV1 receptor protein was higher in cirrhotic than in control vessels. Neither CB1 mRNA nor protein was detected in femoral arteries. Immunochemistry showed that CB1 receptors were mainly in the adventitia and in the endothelial monolayer, with higher expression observed in vessels of cirrhotic rats than in controls.

CONCLUSIONS

These results indicate that anandamide is a selective splanchnic vasodilator in cirrhosis which predominantly acts via interaction with two different types of receptors, CB1 and TRPV1 receptors, which are mainly located in perivascular sensory nerve terminals of the mesenteric resistance arteries of these animals.

Plasma nitrite/nitrate and endothelin-1 concentrations in neonatal sepsis

AIM

To determine the changes in plasma nitrite/nitrate (NOx) and endothelin-1 (ET-1) concentrations during neonatal sepsis.

METHODS

In a prospective study, 60 consecutive newborns meeting the criteria for sepsis and without receiving exogenous nitric oxide (25 haemoculture-positive [HC+] and 35 haemoculture-negative [HC-]) were compared with 68 healthy newborns (46 full-term and 22 preterm). NOx and ET-1 concentrations were measured in each newborn within 48 h of diagnosis of sepsis and then every third day up to three determinations. SNAP-II and SNAPPE-II severity scores were performed at the moment of highest clinical severity.

RESULTS

At the beginning of the sepsis period, controls and septicaemic newborns had similar NOx and ET-1 levels, with the exception of infants with severe HC+ sepsis. Throughout the sepsis period, NOx increased in moderate HC+ sepsis and decreased in HC--sepsis, reaching a significant difference at the end of the study period (59.9 +/- 72.7 vs 33.9 15.3 micromol/L; p = 0.036). Meanwhile, ET-1 in newborns with severe HC+ sepsis remained higher than that in the moderate HC+ sepsis group and HC--group, reaching significant differences in all the periods. The highest ET-1 value was positively correlated with SNAP-II and SNAPPE-II scores.

CONCLUSION

NOx concentrations increased throughout the neonatal HC+ sepsis period, reaching significant differences after 7-9 d. The highest ET-1 levels in neonatal HC+ sepsis emerged before the NOx peak, at 3-5 d, and later decreased. Only newborns with severe HC+ sepsis presented a significant increase in ET-1 concentrations from the beginning of the septicaemic process.

Expired nitric oxide in the newborn with high risk of perinatal infection

The objective of this study is to determine expired nitric oxide (expNO) in the first 3 days of life in relation to: hours of life, gestational age, type of labor, and risk of perinatal infection. Our hypothesis has been that expNO increases in newborns with high risk of perinatal infection. Total expNO was measured in 166 newborns: 108 healthy (63 full-term and 45 preterm), 30 with low risk of perinatal infection, and 28 with high risk of perinatal infection treated with antibiotics but without positive hemoculture. Expired gas was collected using a face mask and NO concentration was determined by chemiluminescence. Total expNO neither correlated with gestational age, birth weight or serum NOx, nor changed after cesarean section, but was related to hours of life. Total expNO in the < or = 36-hour subgroups (median, interquartile range) was higher in the high-risk perinatal infection newborns ( n = 8; 5.33 (4.5-7.2) nL/min*Kg) than in healthy newborns ( n = 59; 4.13 (3.5-4.7) nL/min*kg) or low-risk perinatal infection newborns ( n = 18; 3.99 (3.4-4.7) nL/min*kg). In the 37 to 72-hour subgroups there were also differences between healthy newborns ( n = 49; 4.68 (4.1-5.3) nL/min*kg) or low-risk perinatal infection newborns on the one hand ( n = 12, 4.55 (3.9-5.2) nL/min*kg) and high risk perinatal infection newborns on the other ( n = 20; 9.69 (7.6-11.1) nL/min*kg). Then, total expNO increased in newborns with high risk of perinatal infection, regardless of hours of life.

Increased production of vascular endothelial growth factor in peritoneal macrophages of cirrhotic patients with spontaneous bacterial peritonitis

Spontaneous bacterial peritonitis (SBP) is a common complication of cirrhotic patients with ascites that usually results in renal failure and death despite the efficacy of the current antibiotic therapy. The pathogenesis of these phenomena is poorly known but it has been related to the production of vasoactive cell mediators locally acting on the splanchnic vasculature. Because previous studies showed that peritoneal macrophages of cirrhotic patients may produce high quantities of vascular endothelial growth factor (VEGF), a powerful vessel permeabilizing agent, when stimulated by cytokines and bacterial lipopolysaccharide, the present study was aimed to seek whether peritoneal macrophages of SBP patients are induced to produce increased amounts of VEGF. Our results indicate that the production rate and the messenger RNA (mRNA) and protein expression of this substance are increased in macrophages of patients with SBP in comparison with those of noninfected cirrhotic patients. This characteristic feature is absent in circulating monocytes of these patients. Moreover, enhanced endothelial cell proliferation induced by conditioned medium of macrophages isolated from the ascites of patients with SBP is abolished by anti-VEGF antibody, and peritoneal tissue of cirrhotic patients expresses both VEGF receptors, Flt-1 and KDR. These results, therefore, are consistent with the concept that locally released macrophage-derived VEGF may result in increased vascular permeability and plasma leakage in the peritoneal vessels of cirrhotic patients with SBP.

[Estradiol enhances endothelium-dependent vasodilation via a nitric oxide pathway]

BACKGROUND AND AIM

The mechanisms by which estradiol dilates arterial vessels are still unclear. Our aim was to study if estradiol enhances endothelium-dependent vasodilation in an experimental model of human arteries in vitro, and if this effect is nitric oxide mediated.

METHODS

Using organ bath chambers, we studied 18 arterial rings obtained from left internal mammary arteries during coronary artery bypass grafting surgery. Response to acetylcholine was evaluated at baseline and after the addition of estradiol 10-6 mol/l to the medium, both in the presence or absence of a nitric oxide synthase inhibitor (L-NNA 10-4 mol/l).

RESULTS

Estradiol significantly enhanced the relaxation of the arterial rings in response to acetylcholine (52 +/- 20% after estradiol versus 42 +/- 22% at baseline; n = 10; p = 0.02). However, endothelium-dependent vasodilation relaxation after estradiol addition was not enhanced in the presence of L-NNA (47 +/- 25% after estradiol versus 38 +/- 22% at baseline; n = 8; p = NS).

CONCLUSIONS

Estradiol in vitro enhances endothelium-dependent vasodilation of internal human mammary artery rings; this effect is blunted after the addition to the medium of a nitric oxide inhibitor. Therefore, the vasodilator properties of estradiol at the studied dosage depend on the nitric oxide pathway.

Effect of salt intake on endothelium-derived factors in a group of patients with essential hypertension

The aim of the present study was to evaluate the effects of the level of salt intake on endothelium-derived factors in a group of patients with essential hypertension. A group of 50 patients with essential hypertension who had never been treated for the condition were placed on a low-sodium (50 mmol/day), low-nitrate (400 micromol/day) diet, which was supplemented, in a single-blind fashion, with placebo tablets for the first 7 days and then with NaCl tablets (200 mmol/day) for a further 7 days (total sodium intake 250 mmol/day). At the end of both periods, 24-h ambulatory blood pressure monitoring was performed. In addition, plasma levels and 24-h urinary excretion of nitrites plus nitrates and cGMP were measured, along with plasma levels of endothelin. A high salt intake promoted significant decreases in plasma levels of nitrites plus nitrates (from 41.0+/-2.1 to 32.8+/-1.8 nmol/ml; P<0.001), 24-h urinary nitrate excretion (from 417+/-36 to 334+/-37 micromol/24 h; P=0.045) and plasma endothelin levels (from 5.6+/-0.3 to 4.6+/-0.3 pg/ml; P=0.007). The plasma concentration and 24-h urinary excretion of cGMP were not altered significantly by a high salt intake. We did not find any relationship between endothelium-derived products and 24-h mean blood pressure, at either low or high salt intakes, or between changes induced by the high-salt diet. A high salt intake also induced significant decreases in plasma renin activity, angiotensin II and aldosterone, and a significant increase in atrial natriuretic peptide. We conclude that a high salt intake decreases the plasma concentration and urinary excretion of nitrates and plasma levels of endothelin in patients with essential hypertension, suggesting that the level of salt intake may affect endothelial cell function. However, these alterations are not correlated with changes in blood pressure induced by the high salt intake.

Human hepatic stellate cells secrete adrenomedullin: potential autocrine factor in the regulation of cell contractility

BACKGROUND/AIMS

Hepatic stellate cells (HSCs) are perisinusoidal pericytes which have receptors for vasoactive factors, such as endothelin-1, which can regulate cell contractility in an autocrine manner. It is unknown whether human HSCs have receptors for and are able to synthesize the vasodilator peptide adrenomedullin (ADM), a peptide produced by most contractile cells.

METHODS AND RESULTS

Stimulation of HSCs with ADM resulted in a dose-dependent raise in cAMP concentration (radioimmunoassay) and markedly blunted the endothelin-induced increase in [Ca2+]i and cell contraction, as assessed in cells loaded with fura-2 using a morphometric method. The existence of the receptor CRLR for ADM and their associated proteins RAMP-1 and RAMP-2 was demonstrated by reverse transcriptase-polymerase chain reaction (RT-PCR). Moreover, activated human HSCs spontaneously secreted ADM in the culture medium in a time-dependent manner. ADM secretion was markedly enhanced by tumour necrosis factor-alpha and interleukin-1beta. Specific mRNA for ADM (RT-PCR and Northern blot) was detected in HSCs and increased after incubation of cells with cytokines.

CONCLUSIONS

Human HSCs have functional receptors for ADM, the stimulation of which blunts the contractile effect of endothelin-1. Cultured human HSCs secrete ADM in baseline conditions. This secretion is markedly increased by cytokines. These results suggest that ADM can regulate HSCs' contractility in an autocrine manner.

A prognostic model for predicting survival in cirrhosis with ascites

BACKGROUND/AIMS

Parameters evaluating renal function and systemic hemodynamics are of prognostic significance in cirrhosis with ascites but are rarely used in the evaluation of survival of these patients. The aim of the current study was to develop a prognostic model to estimate survival of patients with cirrhosis and ascites.

METHODS

216 Cirrhotic patients admitted to hospital for the treatment of ascites were evaluated. Thirty-two demographic, clinical and laboratory variables, including parameters assessing liver and renal function and systemic hemodynamics, were analyzed as predictive factors of survival by using a Cox regression model.

RESULTS

Four variables had independent prognostic value: renal water excretion, as assessed by measuring diuresis after water load, mean arterial pressure, Child-Pugh class, and serum creatinine. According to these features a prognostic index was calculated that allows to estimate survival in patients with cirrhosis and ascites. The model accurately predicted survival in an independent series of 84 patients with cirrhosis and ascites.

CONCLUSION

A prognostic model that uses four easily available variables and predicts prognosis in cirrhotic patients with ascites has been developed. This model may be useful in the evaluation of patients with ascites for liver transplantation.

Long-term aquaretic efficacy of a selective nonpeptide V(2)-vasopressin receptor antagonist, SR121463, in cirrhotic rats

Water retention in experimental cirrhosis can be reversed by blocking V(2)-vasopressin (AVP) receptors with the nonpeptide antagonist OPC-31260 or by using the kappa-opioid receptor agonist niravoline, a compound inhibiting central AVP release. However, reluctance to use these drugs in human beings has emerged because the former loses aquaretic efficacy in rats after 2 days of treatment and the latter may have adverse effects in humans. Recently, a new potent and selective nonpeptide V(2)-AVP receptor antagonist, SR121463, has been developed that could be useful for the treatment of dilutional hyponatremia in human cirrhosis. The current study assessed the aquaretic efficacy of 10-day chronic oral administration of SR121463 (0.5 mg/kg/day) in cirrhotic rats with ascites and impaired water excretion after a water load (minimum urinary osmolality >160 mOsm/kg and percentage of water load excreted <60%). Urine volume (UV), osmolality (U(Osm)V), and sodium excretion (U(Na)V) were measured daily. At the end of the 10-day treatment, mean arterial pressure also was measured. In basal conditions cirrhotic rats showed ascites, sodium retention, and impaired water excretion. UV, U(Osm)V, and U(Na)V did not change throughout the study in cirrhotic rats receiving the vehicle. In contrast, SR121463 increased UV and reduced U(Osm)V during the 10-day treatment. This resulted in a greater renal ability to excrete a water load and normalization in serum sodium and osmolality. During the first 6 days of treatment, SR121463 also increased U(Na)V without affecting mean arterial pressure. These data suggest that SR121463 could be of therapeutical value for chronic management of human cirrhosis.

[Increased adrenomedullin levels in hypertensive patients on maintenance hemodialysis]

Hypertension is a frequent finding in uremic patients. The pathogenesis of this complication in uremia is complex and not fully elucidated. An imbalance between the vasoconstrictor and vasodilator systems may be involved in its pathogenesis. In this study we have evaluated the state of nitric oxide (NO) and adrenomedullin (ADM) in hemodialyzed patients, especially those with hypertension. We included a group of hypertensive hemodialyzed patients (n = 9) and a group of normotensive control patients (n = 10). We measured plasma renin activity, as well as plasma catecholamines, ADM, and nitrite/nitrate levels in basal conditions before starting the hemodialysis session. Plasma volume, as well as left ventricular ejection fraction were also measured. Hemodialysis patients showed plasma levels of nitrite/nitrates and ADM higher than the reference values in the normal population. We observed no differences in the plasma levels of nitrite/nitrates, but ADM levels were higher in hypertensive (278.2 +/- 15.5 pg/ml) patients than in normotensive patients (225 +/- 9.9 pg/ml) (p < 0.05). When considering all patients together, mean arterial pressure positively correlated with plasma ADM (r = 0.468, p < 0.05). Plasma volume and left ventricular ejection fraction were similar in the two groups of patients. In summary, plasma levels of nitrite/nitrates and ADM are increased in hemodialyzed patients, although only ADM levels were further increased in hypertensive patients. Our results do not suggest that a decreased production in the vasodilator factors evaluated is involved in the pathogenesis of hypertension in uremic patients.

Hepatocyte-derived cysteinyl leukotrienes modulate vascular tone in experimental cirrhosis

BACKGROUND & AIMS

The leukotrienes C(4)/D(4)/E(4) (cysteinyl-LTs) are 5-lipoxygenase (5-LO)-derived eicosanoids with potent vasoconstrictor, proliferative, and profibrogenic properties that may participate in key pathophysiologic events in liver cirrhosis. We examined the cysteinyl-LT biosynthetic pathway in liver tissue and purified liver cells isolated from rats with carbon tetrachloride-induced cirrhosis, and assessed the vasoactive properties of LTD(4) in hepatic stellate cells (HSCs) and anesthetized rats.

METHODS & RESULTS

Liver homogenates from cirrhotic rats had increased 5-LO mRNA and cysteinyl-LT content, as determined by Northern blot and enzyme immunoassay, respectively. In isolated rat liver cells, 5-LO mRNA expression was found to be restricted to Kupffer cells. However, among the liver cells (i.e., hepatocytes, Kupffer cells, HSCs, and sinusoidal endothelial cells), hepatocytes exhibited the highest ability to generate cysteinyl-LTs from the unstable intermediate LTA(4). Hepatocytes from cirrhotic rats showed an enhanced baseline generation of cysteinyl-LTs, but their ability to synthesize cysteinyl-LTs from exogenous LTA(4) was found to be similar to that of hepatocytes from normal animals. Both LTD(4) and hepatocyte-conditioned medium increased intracellular Ca(2+) concentration and induced contraction in HSCs, suggesting that hepatocyte-derived cysteinyl-LTs could act in a paracrine fashion on nearby nonparenchymal liver cells. The relevance of these in vitro findings was further established in vivo by the observation that LTD(4) significantly increased portal pressure in anesthetized rats.

CONCLUSIONS

These data suggest a role for hepatocyte-derived cysteinyl-LTs in mediating hepatic vascular tone abnormalities in cirrhosis.

Terlipressin plus albumin infusion: an effective and safe therapy of hepatorenal syndrome

BACKGROUND/AIM

Ornipressin, a vasopressin analog with potent splanchnic vasoconstrictor action, has been shown to reverse hepatorenal syndrome. However, its usefulness in clinical practice is limited by frequent ischemic complications. The aim of this study was to assess the efficacy of terlipressin, an analog of vasopressin with a low profile of side effects, plus albumin in this condition.

METHODS

Nine consecutive patients with cirrhosis and hepatorenal syndrome were included in a pilot study of terlipressin (0.5-2 mg/4 h i.v.) therapy associated with iv albumin.

RESULTS

Treatment (9 days, range 5-15) was associated with a marked reduction of serum creatinine (3.9+/-0.7 to 1.3+/-0.1 mg/dl, p<0.001, mean+/-SE). Reversal of hepatorenal syndrome (reduction of creatinine below 1.5 mg/dl) was observed in seven of the nine patients. There was a remarkable improvement in circulatory function, with an increase in mean arterial pressure (68+/-2 to 80+/-4 mmHg, p<0.05) and suppression of vasoconstrictor systems activity (plasma renin activity and plasma norepinephrine decreased from 23+/-12 ng/ml x h and 1549+/-373 pg/ml to 3.5+/-2 ng/ml x h and 373+/-98 pg/ml, respectively, p<0.01 for both). No patient developed signs of intestinal, myocardial or distal ischemia.

CONCLUSIONS

Terlipressin associated with albumin appears to be a safe and effective treatment of hepatorenal syndrome.

Circulating levels of nitric oxide in successful and unsuccessful implantation after in vitro fertilization and embryo transfer. Relationship to estradiol and progesterone

BACKGROUND

Nitric oxide (NO) may play an important role in embryo implantation and early embryo development. This study investigated the potential role of circulating nitric oxide (NO) measurement to predict the outcome of implantation and pregnancy after IVF and ET.

METHODS

Two blood samples were collected from 237 IVF patients on days 13-14 and 20-21 after ET. Serum concentration of nitrite/nitrate (the two stable oxidation products of NO metabolism), estradiol (E2), progesterone and beta-hCG were measured on days 13-14 after ET and one week later.

RESULTS

No significant differences were found with respect to nitrite/nitrate serum concentrations in conception versus non-conception cycles, viable versus abnormal pregnancies, and viable pregnancy group versus non-conception cycles, respectively, despite that significant differences were observed regarding E2 and progesterone values. Nitrite/nitrate serum concentrations were similar for singleton and multiple pregnancies at both study points. In viable pregnancies, no significant change was observed for nitrite/nitrate serum concentration from days 13-14 to 20-21 after ET. No correlation was found between nitrite/nitrate serum concentration and E2 or progesterone serum levels.

CONCLUSIONS

Circulating levels of nitrite/nitrate are similar in successful and unsuccessful implantation after IVF and are unrelated to the outcome of pregnancy. This precludes the use of serum NO measurement as a marker of implantation and successful pregnancy in IVF.

Follicular fluid concentrations of adrenomedullin, vascular endothelial growth factor and nitric oxide in IVF cycles: relationship to ovarian response

Marked granulosa cell proliferation along with important changes in the vascular bed of the ovary characterize IVF cycles associated with multiple follicular growth and maturation. The present report investigated follicular fluid (FF) and circulating concentrations of adrenomedullin, vascular endothelial growth factor (VEGF) and nitric oxide (NO) in 70 IVF patients (14 of whom became pregnant); these three vasoactive substances may be implicated in extensive ovarian tissue remodelling. Serum and FF concentrations of oestradiol and progesterone were also measured in the 70 IVF cycles studied. Follicular fluid concentrations of VEGF and adrenomedullin but not nitrite/nitrate (the two stable oxidation products of NO metabolism) were significantly higher (P < 0.0001) than the corresponding circulating concentrations. Follicular fluid concentrations of oestradiol and progesterone were not correlated with those of adrenomedullin, VEGF or nitrite/nitrate. No relationship existed between circulating concentrations of adrenomedullin, VEGF or nitrite/nitrate on the day of oocyte aspiration and parameters of ovarian response to gonadotrophin stimulation. In contrast, FF adrenomedullin concentration showed a direct relationship with day 3 FSH serum concentration (r = 0.53, P < 0.01) and the number of ampoules of gonadotrophin administered (r = 0.36, P < 0.005), but an inverse correlation with the total number of oocytes retrieved (r = -0.29, P < 0.01) and the number of mature oocytes (r = -0.25, P < 0. 05). A positive correlation was found for FF VEGF concentration and chronological age (r = 0.29, P < 0.05) and ampoules of gonadotrophins administered (r = 0.30, P < 0.05). There was no relationship between nitrite/nitrate FF concentrations and parameters of ovarian response. Neither serum concentrations nor FF concentrations of adrenomedullin, VEGF or nitrite/nitrate were correlated with IVF outcome. This study suggested for the first time that increased FF concentrations of adrenomedullin can be a marker of decreased ovarian response in IVF. Our results also provide further evidence favouring an association between FF VEGF and patient's age, while on the basis of our findings NO measurements are not a useful marker of ovarian response.

Complications of cirrhosis. II. Renal and circulatory dysfunction. Lights and shadows in an important clinical problem

The pathophysiology of circulatory and renal dysfunction in cirrhosis and the treatment of ascites and related conditions (hepatorenal syndrome and spontaneous bacterial peritonitis) have been research topics of major interest during the last two decades. However, many aspects of these problem remain unclear and will constitute major areas of investigation in the next millennium. The pathogenesis of sodium retention, the most prevalent renal function abnormality of cirrhosis, is only partially known. In approximately one third of patients with ascites, sodium retention occurs despite normal activity of the renin-aldosterone and sympathetic nervous systems and increased circulating plasma levels of natriuretic peptides and activity of the so-called natriuretic hormone. These patients present an impairment in circulatory function which, although less intense, is similar to that of patients with increased activity of the renin-aldosterone and sympathetic nervous systems, suggesting that antinatriuretic factors more sensitive to changes in circulatory function that these systems may be important in the pathogenesis of sodium retention in cirrhosis. The development of drugs that inhibit the tubular effect of antidiuretic hormone and increase renal water excretion without affecting urine solute excretion has opened a field of great interest for the management of water retention and dilutional hyponatremia in cirrhosis. Two families of drugs, the V2 vasopressin receptor antagonists and the kappa-opioid agonists, have been shown to improve free water clearance and correct dilutional hyponatremia in human and experimental cirrhosis with ascites. The first type of drugs blocks the tubular effect of antidiuretic hormone and the second inhibits antidiuretic hormone secretion by the neurohypophysis. On the other hand, two new treatments have also been proved to reverse hepatorenal syndrome in cirrhosis. The most interesting one is that based on the simultaneous administration of plasma volume expansion and vasoconstrictors. The second is transjugular intrahepatic porto-systemic shunt. The long-term administration (1-3 weeks) of analogs of vasopressin (ornipressin or terlipressin) or other vasoconstrictors together with plasma volume expansion with albumin is associated with a dramatic improvement in circulatory function and normalization of serum creatinine concentration in patients with severe hepatorenal syndrome. Of interest is the observation that in many of these patients, hepatorenal syndrome does not recur following discontinuation of the treatment, thus raising important questions about the mechanism by which hepatorenal syndrome follows a progressive course in most untreated cases. The pathogenesis of circulatory dysfunction in cirrhosis and the role of local mechanisms in the development of the splanchnic arteriolar vasodilation associated with portal hypertension will continue as important topics in clinical and basic research in Hepatology. Of special interest is the study of the mechanism by which circulatory function further deteriorates following complications such as severe bacterial infection or therapeutic interventions such as therapeutic paracentesis, and the adverse consequences of the impairment in circulatory function on renal and hepatic hemodynamics. Finally, although major advances have been made concerning the treatment and secondary prophylaxis of spontaneous bacterial peritonitis in cirrhosis, many aspects of the pathogenesis of this infection remain unclear. The mechanism of bacterial translocation and of the colonization of bacteria in the ascitic fluid are particularly important to design adequate measures for primary prophylaxis of this severe bacterial infection.

Increased activity of guanosine 3'-5'-cyclic monophosphate phosphodiesterase in the renal tissue of cirrhotic rats with ascites

A possible defect of guanosine 3'-5'-cyclic monophosphate (cGMP) content in the renal tissue caused by an increased activity of cGMP phosphodiesterase (PDE) has, so far, not been evaluated in the pathogenesis of renal resistance to endogenous natriuretic peptides (ENP) in cirrhosis with ascites. To test this hypothesis the activity of cGMP-PDE and the concentration of cGMP were evaluated in vitro in the renal tissue of 10 control rats and 10 cirrhotic rats with ascites before and after the intravenous (IV) administration of Zaprinast (Sigma, St. Louis, MO), a specific cGMP-PDE inhibitor (30 microgram/kg/min). Moreover, the effects of the intravenous administration of Zaprinast (15 microgram/kg/min and 30 microgram/kg/min) on renal plasma flow (RPF), glomerular filtration rate (GFR), and urinary sodium excretion (U(Na)V) were evaluated in 10 conscious control rats and 10 conscious cirrhotic rats with ascites. The effects of Zaprinast on plasma renin activity (PRA) was also evaluated in 10 control rats and in 10 cirrhotic rats with ascites. Finally, the effect of Zaprinast on RPF, GFR, and U(Na)V were evaluated in 10 cirrhotic rats after the IV administration of the ENP-receptor antagonist, HS-142-1. The renal content of cGMP was reduced in cirrhotic rats because of increased activity of cGMP-PDE. Zaprinast inhibited cGMP-PDE activity and increased the renal content of cGMP in these animals. The inhibition of cGMP-PDE was associated with an increase in RPF, GFR, and U(Na)V and a reduction in PRA. HS-142-1 prevented any renal effect of Zaprinast in cirrhotic rats. In conclusion, an increased activity of the cGMP-PDE in renal tissue contributes to the renal resistance to ENP in cirrhosis with ascites.

Nitric oxide synthase II mRNA expression in cardiac tissue of patients with heart failure undergoing cardiac transplantation

OBJECTIVES

To examine whether inducible nitric oxide synthase is expressed in myocardial tissue of patients with heart failure.

BACKGROUND

There is increasing evidence that alterations in nitric oxide synthesis are of pathophysiologic importance in heart failure. Nitric oxide (NO) can exert negative inotropic and cytotoxic effects on cardiomyocytes. A number of studies have shown altered nitric oxide production by the endothelial constitutive isoform of nitric oxide synthase (NOS III), but there is little information on the role of NOS II. Expression of NOS II could lead to excessive production of NO in the myocardium and affect cardiac contractility.

METHODS

NOS II mRNA expression in myocardial tissue of 18 patients with idiopathic dilated cardiomyopathy (DCM), 7 patients with ischemic cardiopathy and severe ventricular dysfunction (ISCH), 4 patients with acute myocardial infarction (AMI) and 11 controls. Serum concentration of NO2-/NO3- (NOx) was also measured.

RESULTS

NOS II gene expression occurred in all the patients with DCM, in 1 out of the 7 ISCH patients, in 2 out of the 4 patients with AMI and in none of the controls. Moreover, DCM patients showed a significant 6-fold increase in NOx concentration (253+/-47 nm/ml) as compared to controls (40+/-2 nm/ml) P < 0.001, a phenomenon not observed in ISCH patients (56+/-3 nm/ml).

CONCLUSIONS

NOS II expression occurs in failing human cardiac myocytes and can play an specific role in the pathogenesis of DCM.

Clinical implications of increased plasma angiotensin II despite ACE inhibitor therapy in patients with congestive heart failure

AIMS

The aim of the study was to assess the incidence and clinical implications of increased plasma angiotensin II despite chronic ACE inhibitor therapy in patients with heart failure.

METHODS AND RESULTS

The studied population consisted of 70 patients (mean age 59+/-9 years). Plasma renin activity and plasma concentration of aldosterone, norepinephrine, atrial natriuretic peptide, angiotensin II, tumour necrosis factor, interleukin-6 and interleukin-1B were assessed at 6 months of ACE inhibitor therapy. Mean left ventricular ejection fraction was 24+/-5% and the end-systolic and end-diastolic diameters were 59+/-9 and 71+/-8 mm, respectively. Despite chronic enalapril or captopril therapy, 35 patients (50%) had increased plasma angiotensin II (median 33 pg. ml(-1), range 17-84), while it was in the normal range in the remaining 35 patients (median 10 pg. ml(-1), range 5-15). Plasma renin activity (P=0.005), interleukin-6 (P=0.004), New York Heart Association functional class III-IV (P=0. 006), furosemide dose (P=0.01), lack of beta-blocker therapy (P=0. 04) and norepinephrine (P=0.04) were univariately associated with increased angiotensin II. Multivariate regression analysis identified the plasma renin activity (0.0004), norepinephrine (0.02) and interleukin-6 (0.03) as independent predictors of plasma angiotensin II. During follow-up (35+/-29 months), nine (12.8%) patients died and 13 had new heart failure episodes. Increased plasma angiotensin II, despite ACE inhibitor therapy, was a significant predictor of death or heart failure according to the Kaplan-Meier survival method by log rank test (P=0.002).

CONCLUSION

Fifty per cent of patients with heart failure, ha increased plasma angiotension II despite chronic ACE inhibitor therapy. These patients had higher neurohormonal activation and poor prognosis.

Nitric oxide production and inducible nitric oxide synthase expression in peritoneal macrophages of cirrhotic patients

The present study assessed whether peritoneal macrophages isolated from cirrhotic patients produce nitric oxide (NO) and express NO synthase type II (NOS II) mRNA and protein. Patients with cirrhosis and ascites without peritonitis or with unresolved or resolved spontaneous bacterial peritonitis (SBP) were studied. Following paracentesis, ascites NO(2)(-) + NO(3)(-) content (NOx) was measured. Peritoneal macrophages from ascites were seeded on well plates, and NO(2)(-) in the medium was determined. NOx was higher in patients with unresolved or resolved SBP than in cirrhotic patients without peritonitis. Macrophages of patients with SBP or resolved SBP produced NO(2)(-) after 30 hours in culture, but those obtained from patients without peritonitis did not. Reverse-transcription polymerase chain reaction (RT-PCR) and immunocytochemical analysis revealed the presence of a clear signal for NOS II mRNA and protein in macrophages of SBP patients, regardless of whether or not the infection subsided. Therefore, peritoneal macrophages isolated from cirrhotic patients with unresolved or resolved SBP produce NO and express the NOS II mRNA and protein, suggesting that NOS II may contribute to the control of SBP, or to its associated pathology, in human cirrhosis.

Adrenomedullin and nitric oxide in menstrual and in vitro fertilization cycles. Relationship to estradiol

BACKGROUND

Estradiol has marked systemic vasodilator effects which may be partially mediated by nitric oxide. Recently, a new vasodilator peptide, adrenomedullin, having potent vasodilatory action which is mediated at least in part by nitric oxide, has been isolated. This study investigated whether a relationship exists between circulating levels of estradiol, adrenomedullin, and nitrite/nitrate (the two stable oxidation products of NO metabolism) both in the spontaneous menstrual cycle and IVF cycles.

METHODS

Ten normal ovulatory infertile patients were included in this prospective longitudinal study. Circulating levels of estradiol, adrenomedullin, and nitrite/nitrate were investigated. Follicular fluid concentrations of adrenomedullin and nitrite/nitrate, as well as estradiol, were also determined in IVF cycles.

RESULTS

Serum nitrite/nitrate levels were significantly elevated in the late follicular phase compared to cycle day 3 of the spontaneous menstrual cycle thus paralleling plasma estradiol. However, no significant change in serum nitrite/nitrate concentration was found associated to multifollicular development and supraphysiological levels of estradiol in IVF cycles. Adrenomedullin plasma levels did not show significant variation either in menstrual or IVF cycles. No correlation was found between plasma estradiol levels and nitrite/nitrate serum concentrations or adrenomedullin plasma levels nor between circulating adrenomedullin and nitrite/nitrate both in menstrual and IVF cycles. Follicular fluid concentrations of estradiol and adrenomedullin but not nitrite/nitrate were significantly higher than those found in plasma or serum. Neither estradiol follicular fluid concentration correlated with those of adrenomedullin or nitrite/nitrate nor a relationship was observed between adrenomedullin and nitrite/nitrate.

CONCLUSIONS

Circulating levels of nitrite/nitrate show a significant increase during the late follicular phase in the normal menstrual cycle which is unrelated to adrenomedullin. In addition, this does not necessarily indicate a cause and effect relationship between nitrite/nitrate and estradiol levels given that no increase in nitrite/nitrate was observed from a hypoestrogenic to a hyperestrogenic state during IVF cycles. Further studies are necessary to clarify this subject. Also, the biological and clinical significance of the presence of adrenomedullin in the human follicular fluid remains to be elucidated.

Selective inhibition of cyclooxygenase 2 spares renal function and prostaglandin synthesis in cirrhotic rats with ascites

BACKGROUND & AIMS

The critical role of cyclooxygenase (COX) products in maintenance of renal function in cirrhosis with ascites discourages the use of nonsteroidal anti-inflammatory drugs in this disease. The recent development of selective COX-2 inhibitors opens new avenues for the use of these compounds in decompensated cirrhosis. The current study evaluates the effects of a selective COX-2 inhibitor (SC-236) on renal function in cirrhotic rats with ascites.

METHODS

In protocol 1, urine volume, urinary excretion of sodium and prostaglandins, glomerular filtration rate, and renal plasma flow were measured before and after administration of SC-236 (n = 12) or ketorolac (n = 10) to rats with cirrhosis. Protocol 2 was aimed at assessing the effects of COX inhibitors on renal water metabolism in 28 cirrhotic rats.

RESULTS

Administration of SC-236 to cirrhotic animals did not produce significant renal effects, whereas administration of the nonselective COX-1/COX-2 inhibitor, ketorolac, resulted in a marked reduction in urine volume, urinary excretion of prostaglandins, and glomerular filtration rate and in a significant impairment in renal water metabolism.

CONCLUSIONS

These findings indicate that SC-236 does not significantly impair renal function in rats with cirrhosis.

Ascites and liver test abnormalities during severe ovarian hyperstimulation syndrome

OBJECTIVE

Severe ovarian hyperstimulation syndrome is an uncommon cause of ascites that is being increasingly recognized because of the high number of women undergoing assisted reproductive techniques, mainly in vitro fertilization. This prospective study investigates the clinical and biochemical characteristics of a large series of patients with this syndrome and ascites, including renal and electrolyte abnormalities, activity of neurohormonal systems participating in the regulation of extracellular fluid volume, and liver function tests.

METHODS

This was a prospective longitudinal study including 50 consecutive patients with ascites due to severe ovarian hyperstimulation syndrome. Renal function, serum electrolytes, body weight, mean arterial pressure, pulse rate, plasma renin activity, plasma concentration of aldosterone, norepinephrine, antidiuretic hormone and atrial natriuretic peptide, and standard liver function tests were measured during the syndrome and 4-5 wk after recovery. A sample of ascitic fluid was obtained from eight patients for protein measurement and cell count.

RESULTS

At diagnosis, patients had ascites associated with low urinary sodium excretion, oliguria, and hyponatremia. They had also markedly low arterial pressure and increased pulse rate in association with marked activation of vasoconstrictor and antinatriuretic factors. The ascitic fluid was characterized by a high protein concentration, low leukocyte count, and relatively high number of red blood cells. Fifteen (30%) patients had abnormal liver tests characterized by mild to moderate increases in AST (mean 103 +/- 17.1 IU/L) and ALT (76 +/- 8.3 IU/L), which were associated in some cases with increases in gamma-glutamyl transpeptidase or alkaline phosphatase. All abnormalities reverted to normal after the resolution of the syndrome.

CONCLUSIONS

With the increasing use of assisted reproductive techniques, physicians should be aware of severe ovarian hyperstimulation syndrome as a cause of ascites. The syndrome is associated with sodium retention, hyponatremia, arterial hypotension, and marked activation of vasoconstrictor and antinatriuretic systems. In one third of patients, liver tests abnormalities are present.

Comparison of two aquaretic drugs (niravoline and OPC-31260) in cirrhotic rats with ascites and water retention

kappa-Opioid receptor agonists (niravoline) or nonpeptide antidiuretic hormone (ADH) V2 receptor antagonists (OPC-31260) possess aquaretic activity in cirrhosis; however, there is no information concerning the effects induced by the chronic administration of these drugs under this condition. To compare the renal and hormonal effects induced by the long-term oral administration of niravoline, OPC-31260, or vehicle, urine volume, urinary osmolality, sodium excretion, and urinary excretion of aldosterone (ALD) and ADH were measured in basal conditions and for 10 days after the daily oral administration of niravoline, OPC-31260, or vehicle to cirrhotic rats with ascites and water retention. Creatinine clearance, serum osmolality, ADH mRNA expression, and systemic hemodynamics were also measured at the end of the study. Niravoline increased water excretion, peripheral resistance, serum osmolality, and sodium excretion and reduced creatinine clearance, ALD and ADH excretion, and mRNA expression of ADH. OPC-31260 also increased water metabolism and sodium excretion and reduced urinary ALD, although the aquaretic effect was only evident during the first 2 days, and no effects on serum osmolality, renal filtration, and systemic hemodynamics were observed. Therefore, both agents have aquaretic efficacy, but the beneficial therapeutic effects of the long-term oral administration of niravoline are more consistent than those of OPC-31260 in cirrhotic rats with ascites and water retention.

Vascular endothelial growth factor production in peritoneal macrophages of cirrhotic patients: regulation by cytokines and bacterial lipopolysaccharide

Vascular endothelial growth factor (VEGF) is an angiogenic peptide with vascular permeability and relaxing properties. This study assessed whether peritoneal macrophages of cirrhotic patients can be up-regulated to produce VEGF under proper stimulatory conditions. Macrophages were isolated from ascites. VEGF protein secretion and mRNA expression were measured in basal conditions and after stimulation with lipopolysaccharide (LPS), tumor necrosis factor alpha (TNF-alpha), and interleukin-1 (IL-1). These substances induced a time- and dose-dependent increase in both VEGF production and transcript expression. Assays with actinomycin D showed that VEGF mRNA induction is secondary to both higher VEGF gene transcription and mRNA stability. Ascites and plasma concentration of VEGF was also measured in cirrhotic patients with (n = 15) and without (n = 10) spontaneous bacterial peritonitis (SBP). Plasma values did not differ between both groups of patients. However, ascites VEGF levels were higher in SBP patients than in noninfected cirrhotic patients (710 +/- 183 vs. 94 +/- 15 pg/mL; P <.025). These results indicate that cytokines and LPS markedly increase VEGF protein secretion and mRNA expression in macrophages of cirrhotic patients, and suggest that this substance could be an important mediator of the pronounced arterial vasodilation frequently occurring in SBP patients.

Regulation of cyclooxygenase-2 expression in human mesangial cells--transcriptional inhibition by IL-13

Activated mesangial cells may play an important part in glomerulonephritis. Cytokines can modulate the release of prostanoids by human mesangial cells (HMC). We have investigated the effects of pro-inflammatory stimuli on COX-2 expression in HMC and its potential modulation by interleukin (IL)-13. HMC released increased amounts of prostaglandin E2 (PGE2) after treatment with several combinations of IL-1 beta, tumor necrosis factor (TNF)-alpha and/or lipopolysaccharide. Increases in PGE2 correlated with the induction of COX-2 protein expression. The accumulation of PGE2 elicited by a combination of IL-1 beta/TNF-alpha correlated closely with the temporal pattern of COX-2 protein expression, which reflected the induction of COX-2 mRNA. IL-13 inhibited IL-1 beta/TNF-alpha-elicited PGE2 production, as well as COX-2 protein and mRNA expression in a concentration-dependent fashion. With 50 ng.mL-1 IL-13 these parameters were inhibited by 90, 80 and 84%, respectively. In HMC transfected with the 5' regulatory region of the COX-2 gene, IL-13 suppressed cytokine-induced promoter activation. Our results suggest that COX-2 expression is a major target for IL-13-mediated abrogation of prostaglandin release by HMC and support that this process takes place by transcriptional inhibition of the COX-2 gene.

Chronic blockade of endothelin receptors in cirrhotic rats: hepatic and hemodynamic effects

BACKGROUND & AIMS

Because controversial roles have been attributed to activation of the hepatic paracrine endothelin (ET) system in cirrhosis, this study assessed whether chronic ET receptor blockade modifies the development of portal hypertension in cirrhotic rats.

METHODS

Cirrhotic and control rats received the mixed ET receptor antagonist RO 48-5695 or vehicle daily for 10 weeks. At the end of the treatment period, portal pressure, systemic hemodynamics, standard renal and liver function tests, hepatic concentration of hydroxyproline, and liver messenger RNA (mRNA) expression of procollagen type I were measured.

RESULTS

Cirrhotic rats had portal hypertension and hyperdynamic circulation with no differences between animals treated or not treated with the ET-receptor antagonist. However, cirrhotic rats receiving ET-receptor blockade long-term showed a higher hepatic hydroxyproline content and procollagen type I mRNA expression than cirrhotic animals receiving vehicle.

CONCLUSIONS

The results indicate that the liver paracrine ET system does not play a major role in the pathogenesis of portal hypertension and support the concept that this system takes part in an autocrine loop that counteracts the development of liver fibrogenesis.

Effects of increasing blood hemoglobin levels on systemic hemodynamics of acutely anemic cirrhotic patients

BACKGROUND/AIMS

In experimental portal hypertension, blood hemoglobin levels have been shown to influence the hyperdynamic circulatory state. The aim of this study was to assess the hemodynamic effects of increasing hemoglobin concentration in human portal hypertension.

METHODS

Sixteen cirrhotic patients recovering from a variceal bleeding episode were randomly assigned to receive two units of packed red cells or 500 ml of a protein solution. Systemic and portal hemodynamics, and rheological and hormonal parameters were measured at baseline and after expansion.

RESULTS

Both groups were similar with respect to the degree of liver failure, severity of the bleeding episode, activation of the endogenous vasopressor systems, and hemodynamic parameters. The administration of either erythrocytes or a protein solution prompted a similar increase in total blood volume and suppression of vasopressor systems. Both groups of patients experienced similar increases in wedged hepatic venous pressure. Hepatic venous pressure gradient was not significantly modified but tended to increase in erythrocyte-transfused patients. Cardiopulmonary pressures increased, but this increment was significant in the non-blood-transfused patients only. Cardiac output decreased in erythrocyte-transfused patients, while it increased in the group receiving a protein solution. Red blood cell transfusion resulted in an increase in systemic vascular hindrance (resistance/blood viscosity), whereas the administration of a protein solution prompted a decrease in this parameter, thus reflecting true vasoconstriction and vasodilation, respectively.

CONCLUSIONS

An increase in blood hemoglobin in acutely anemic cirrhotic patients attenuates their hyperdynamic circulation beyond viscosity-dependent changes, an effect which might be counteracted by the effects on portal venous pressure gradient.

Insulin therapy in type 2 diabetic patients: effects on arterial blood pressure and endothelin-1 plasma levels

OBJECTIVE

To evaluate the possible effect of short- and long-term insulin treatment on arterial blood pressure (BP) and endothelin-1 (ET-1) plasma levels in type 2 diabetic patients.

RESEARCH DESIGN AND METHODS

Seven type 2 diabetic patients with secondary failure to oral hypoglycemic drugs (SFOH) were studied. Twenty-four-hour arterial BP monitorization (Spacelabs 90207) was performed before initiation of insulin treatment (time 0), 6 days after (time 1) and 1 year later (time 2). Moreover, ET-1 plasma levels were measured.

RESULTS

Insulin treatment did not produce any variation in systolic (124.3 +/- 11.6; 120.7 +/- 7.9; 127.0 +/- 13.4 mmHg) and diastolic (72.8 +/- 5.9; 71.5 +/- 3.4; 71.8 +/- 5.2 mmHg) 24-h BP monitorization at times 0, 1 and 2, respectively. The systolic and diastolic day/night differences did not change in the three times studied. Neither were significant differences observed in ET-1 plasma levels.

CONCLUSIONS

In patients with SFOH, insulin treatment did not induce any short- or long-term increase in BP or any variation in plasma ET-1 levels.

Haematocrit, leukocyte and platelet counts and the severity of the ovarian hyperstimulation syndrome

Previous studies have shown that severe ovarian hyperstimulation syndrome (OHSS) is secondary to circulatory dysfunction due to the simultaneous occurrence of increased vascular permeability and marked arteriolar vasodilation which lead to an intense homeostatic stimulation of the renin-aldosterone and sympathetic nervous systems and antidiuretic hormone (ADH). In the present report, we have investigated the correlation between changes in haematocrit concentration, and white blood cell (WBC) and platelet counts and the severity of OHSS, as assessed by these markers of effective intra-arterial blood volume, in a series of 50 patients. In comparison with recovery values (4-5 weeks after hospital discharge), OHSS patients showed arterial hypotension, tachycardia, oliguria, very high plasma concentrations of renin, aldosterone, norepinephrine and ADH, and increased mean haematocrit values and WBC and platelet counts. The haematocrit concentration values were directly related to the plasma concentrations of vasoactive substances (plasma renin activity, aldosterone, norepinephrine and ADH) during OHSS (P < 0.001). In contrast, no correlation was evident between WBC or platelet counts and neurohormonal measurements during the syndrome. It is concluded that haematocrit, but not WBC or platelet counts, can act as a biological marker of the severity of OHSS as indicated by plasma measurement of volume-dependent endogenous vasoactive substances.

Transjugular intrahepatic portosystemic shunt in hepatorenal syndrome: effects on renal function and vasoactive systems

Little information exists on the effects of transjugular intrahepatic portosystemic shunts (TIPS) in the management of cirrhotic patients with hepatorenal syndrome (HRS). The current study was aimed to prospectively evaluate the effects of TIPS on renal function and vasoactive systems in patients with type I HRS. Glomerular filtration rate (GFR) (inulin clearance), renal plasma flow (RPF) (para-aminohippurate clearance), plasma renin activity (PRA), aldosterone (ALDO), norepinephrine (NE), and endothelin (ET) were determined in baseline conditions and at different time intervals after TIPS in 7 patients with type I HRS. TIPS induced a marked reduction of portal pressure gradient (PPG) (20 +/- 1 to 10 +/- 1 mm Hg; P < .05). Renal function improved in 6 of the 7 patients. Serum creatinine and blood urea nitrogen (BUN) decreased from 5 +/- 0.8 and 109 +/- 7 to 1.8 +/- 0.4 mg/dL and 56 +/- 11 mg/dL, respectively (P < .05 for both), and GFR and RPF increased from 9 +/- 4 and 103 +/- 33 to 27 +/- 7 mL/min and 233 +/- 40 mL/min, respectively (P < .05 for both), 30 days after TIPS. These beneficial effects on renal function were associated with a significant (P < .05) reduction of PRA (18 +/- 5 to 3 +/- 1 ng/mL x h), ALDO (279 +/- 58 to 99 +/- 56 ng/dL), and NE (1,257 +/- 187 to 612 +/- 197 pg/mL). ET did not change significantly (28 +/- 8 to 27 +/- 11 pg/mL). Mean survival was 4.7 +/- 2 months (0.3-17 months). Three patients remained alive more than 3 months after TIPS insertion. In conclusion, TIPS improves renal function and reduces the activity of the renin-angiotensin and sympathetic nervous systems in cirrhotic patients with type I HRS. Nevertheless, the efficacy of TIPS in the management of these patients should be confirmed in controlled investigations.

Increased cerebrovascular resistance in cirrhotic patients with ascites

Studies assessing regional hemodynamics in patients with cirrhosis and ascites have shown vasodilation in the splanchnic circulation and vasoconstriction in the renal circulation and in the brachial and femoral artery vascular territories. The aim of this study was to assess the cerebral vascular resistance in cirrhotic patients with ascites. The resistive index in the middle cerebral artery (an index of the cerebral vascular resistance) and in a renal interlobar artery were measured by Doppler ultrasonography in 7 healthy subjects: 13 patients with compensated cirrhosis and 24 patients with ascites (13 with renal failure). The arterial blood pressure and the activity of the renin-angiotensin and sympathetic nervous systems, as estimated by plasma renin activity and plasma norepinephrine concentration, respectively, were also measured. The resistive index in the middle cerebral artery was significantly increased in patients with ascites (0.68 +/- 0.05, mean +/- SD) as compared with patients without ascites (0.60 +/- 0.01, P < .05) and with healthy patients (0.52 +/- 0.01, P < .01). Renal resistive index was also increased in patients with ascites (0.77 +/- 0.01) compared with the other two groups (0.68 +/- 0.02 and 0.62 +/- 0.00, respectively; P < .001). The resistive index in the middle cerebral artery showed a direct correlation with renal resistive index (r = .73, P < .01), plasma renin activity (r = .61, P < .01), and norepinephrine (r = .53, P < .01). The resistive index in the middle cerebral artery showed an inverse correlation with mean arterial pressure (r = -.45, P < .01). These results indicate that in patients with cirrhosis and ascites there is a cerebral vasoconstriction which is probably related with the arterial hypotension and the overactivity of vasoconstrictor systems.

Altered biosynthesis of leukotrienes and lipoxins and host defense disorders in patients with cirrhosis and ascites

BACKGROUND & AIMS

Advanced cirrhosis is associated with impaired leukocyte function, but the mechanism underlying this host defense alteration is unknown. The aim of this study was to investigate the lipoxygenase pathway of arachidonic acid metabolism and its influence in leukocyte trafficking in patients with cirrhosis and ascites.

METHODS

Neutrophils (polymorphonuclear leukocytes [PMN]) were isolated from patients with cirrhosis and ascites and healthy subjects, and 5-lipoxygenase (5-LO) messenger RNA levels and 5-LO-derived products were measured. The effect of leukotrienes (LT) and lipoxins (LX) on PMN adhesion and migration was also assessed.

RESULTS

PMN from patients with cirrhosis showed increased 5-LO messenger RNA expression. However, in vitro generation of LTB4, cysteinyl-containing LT and LX was significantly decreased in cirrhotic patients. Interestingly, a close relationship between the activity of the renin-angiotensin system and LXA4 biosynthesis was observed both in vitro and in vivo. PMN isolated from cirrhotic patients with ascites showed significantly decreased adhesion and migration in response to LTB4. LXA4 did not provoke PMN adhesion and migration, but rather abrogated the differences between control and cirrhotic PMN. Cirrhotic monocytes showed marked impairment in adherence to laminin when stimulated with either LTB4 or LXA4.

CONCLUSIONS

These results show the existence of altered biosynthesis of LT and LX and defective response to these lipoxygenase products in leukocytes from patients with cirrhosis and ascites. This abnormality may be relevant to the pathogenesis of host defense disorders in chronic liver disease.

Increased renal expression of nitric oxide synthase type III in cirrhotic rats with ascites

This article assesses the circulating levels of L-arginine, the renal response to L-arginine infusion, and the renal expression of inducible and constitutive nitric oxide synthase (NOS II and NOS III, respectively) in cirrhotic rats with ascites. Systemic and renal hemodynamics and renal function were measured in basal conditions and following two doses of L-arginine (5 and 10 mg x kg(-1) x min for 40 minutes). Renal NOS II and III messenger RNA (mRNA) expression was evaluated in basal conditions by polymerase chain reaction and Northern blot, respectively. Renal NOS II and III protein expression was assessed by Western blot and immunohistochemistry. Plasma concentration of L-arginine was significantly lower in cirrhotic rats than in control rats (48+/-11 vs. 86+/-9 micromol/L, P < .025). In both groups L-arginine infusion had no effect on systemic hemodynamics, but markedly increased renal perfusion. This effect was significantly more intense in cirrhotic rats. A very weak signal of similar intensity was found for NOS II mRNA in both groups of animals. However, no NOS II protein expression was detected. In contrast, higher NOS III mRNA abundance and protein expression, which was mainly located in the endothelial lining of the renal arterioles, were found in the kidney of cirrhotic animals. These results indicated increased renal expression of NOS III mRNA and protein, deficient circulating levels of L-arginine, and increased renal hemodynamic response to this amino acid in cirrhotic rats with ascites. Our results suggest that L-arginine supplementation at doses not affecting arterial pressure could have beneficial effects on renal perfusion in cirrhosis.

Circulatory dysfunction in asymptomatic in vitro fertilization patients. Relationship with hyperestrogenemia and activity of endogenous vasodilators

Severe ovarian hyperstimulation syndrome (OHSS) is consistently associated with a circulatory dysfunction characterized by arterial hypotension, low peripheral vascular resistance, and increased activity of the renin-aldosterone system. To investigate whether circulatory dysfunction also occurs in asymptomatic patients undergoing controlled gonadotropin ovarian hyperstimulation under pituitary suppression for in vitro fertilization (IVF), 12 women without clinical manifestations of OHSS underwent sequential blood, urine, and hemodynamic measurements at five study points: the 7th day of the menstrual cycle preceding IVF (study point 1 or baseline), the day when pituitary suppression was shown (study point 2), the day of hCG ovulatory injection (study point 3), the day after hCG was injected (study point 4), and 7 days after hCG administration (study point 5). Mean arterial pressure, cardiac output, peripheral vascular resistance, plasma concentrations of estradiol (E2) and aldosterone, and plasma renin activity (PRA) were measured at each study point in all women. Serum levels of nitrite/nitrate, and plasma concentration of atrial natriuretic peptide, norepinephrine, adrenomedullin, and cyclic guanosine 3'5'-monophosphate were measured in samples obtained at study points 1 and 5. Multiple follicular development during ovarian stimulation associated with increased plasma E2 concentration (mean peak plasma E2 level, 2430 +/- 428 pg/mL, range 1630-3840 pg/mL) were observed in each woman. All patients developed a significant increase in cardiac output and decrease in arterial pressure and peripheral vascular resistance, and a marked elevation in PRA and aldosterone, all indicating the development of arteriolar vasodilation. Changes in circulatory measurements were temporarily related with the increase in E2 both being detected at study points 3-5. In contrast, there was a clear chronological dissociation between the increase in plasma E2 concentration and the stimulation of the renin-aldosterone system. PRA and aldosterone only reached abnormal levels at study point 5 in association with a significant increase in plasma norepinephrine concentration. Serum levels of nitrite/nitrate and plasma concentrations of atrial natriuretic peptide, adrenomedullin, and cyclic GMP were similar at study points 1 and 5. It is concluded that the circulatory dysfunction that characterizes severe OHSS is a universal event in patients undergoing controlled ovarian hyperstimulation for IVF. Although the increase in E2 levels during IVF cycles is associated with significant circulatory changes, the circulatory dysfunction that characterizes severe OHSS is clearly unrelated to the onset of hyperestrogenemia. Arteriolar vasodilation during IVF cycles was not associated with an increased activity of the vasodilator substances atrial natriuretic peptide, adrenomedullin, and nitric oxide.

Tumor necrosis factor and interleukin-6 in spontaneous bacterial peritonitis in cirrhosis: relationship with the development of renal impairment and mortality

Spontaneous bacterial peritonitis (SBP) is associated with an important production of inflammatory mediators. However, it is unknown whether there is a relationship between the abdominal production of these mediators and the development of renal impairment, one of the most important prognostic parameters in spontaneous bacterial peritonitis. We studied 52 cirrhotic patients at diagnosis and resolution of the infection, by measuring endotoxin, tumor necrosis factor (TNF), and interleukin-6 (IL-6) levels in plasma and ascitic fluid. Thirteen patients (25%) developed renal impairment. Patients developing renal impairment showed significantly higher plasma and ascitic fluid cytokine levels at diagnosis of infection than patients who did not (plasma TNF-alpha: 96.0+/-38.7 vs. 39.1+/-3.6 pg/mL, P=.0209; ascitic fluid TNF-alpha: 474.5+/-118.1 vs. 160.8+/-42.7 pg/mL, P=.0173; plasma IL-6: 6,635+/-2,897 vs. 458+/-109 pg/mL, P=.0004; ascitic fluid IL-6: 182,559+/-47,328 vs. 39,250+/-10,803 pg/mL, P=.0001). Independent predictors of development of renal impairment at diagnosis were: renal failure (blood urea nitrogen > 30 mg/dL or serum creatinine > 1.5 mg/dL) (P < .001), IL-6 levels in ascitic fluid (P < .001), and mean arterial pressure (P < .05). Ten of the 13 (77%) patients who developed renal impairment died during hospitalization, but only 2 of the 39 (5%) patients who did not (P=.0001). In addition, renal failure at diagnosis of the infection was the only independent predictor of hospital mortality (P < .001). In conclusion, the inflammatory response to the infection may be an important mechanism of renal impairment and the associated mortality in SBP.