Causes of altered liver function tests - the role of alpha-1 antitrypsin.

BACKGROUND: Altered liver function tests are a common finding in clinical practice. Our retrospective study aimed to identify the diagnoses in a non-selected cohort of patients with altered liver tests and to investigate whether alpha-1 antitrypsin genotyping should be part of the diagnostic workup. PATIENTS AND METHODS: 501 patients who were admitted to our outpatient clinic for further evaluation of altered liver function tests were included in the study. The patients underwent a standardized diagnostic program with history taking, physical examination, laboratory tests and ultrasonography. Liver biopsy was performed if appropriate. RESULTS: More than 50 % of the patients had nonalcoholic fatty liver disease. Alcoholic and drug-induced liver injury were found in 8.6 % and 7 % of patients, respectively. Chronic hepatitis B and C, autoimmune liver disease and inherited causes of liver disease made up for approximately 16 % of the diagnoses. The remaining patients were diagnosed with kryptogenic liver disease or had miscellaneous diagnoses. In 3.7 % of the genotyped patients, the alpha-1 antitrypsin genotype PiMZ was found. CONCLUSION: Nonalcoholic fatty liver disease is nowadays the most frequent cause of altered liver tests. Alcoholic liver disease might be underrepresented in our study since these patients less often seek medical attention or the diagnosis is already made by the primary care physician. Drug-induced liver injury was found in more patients than expected and might therefore be underdiagnosed in practice. The alpha-1 antitrypsin genotype PiMZ was found in absence of other possible causes of liver disease, indicating that the PiMZ genotype is itself a risk factor for liver disease. Genotyping for alpha-1 antitrypsin should therefore be done when other causes for altered liver function tests have been ruled out.

[Recurring, severe upper abdominal pain in a 45 year old patient]. / Rezidivierende, stärkste Oberbauchschmerzen bei einem 45-jährigen Patienten.

A 45-year-old patient presented with a history of recurrent abdominal pain of unknown origin. The CT scan of the abdomen demonstrated a thickened mesenteric root and a segmental ileus of the jejunum. Laparotomy revealed a neuroendocrine tumour of the small bowel. Such tumours are rare causes of recurrent abdominal pain. Especially when the CT scan of the abdomen reveals mesenteric abnormalities (desmoplastic reaction) and/or a segmental ileus, a neuroendocrine tumour of the small bowel should be considered. The therapy of choice is resection of the tumour followed by systemic therapy including somatostain analogues and chemotherapy in the case of a hormone secreting tumour or metastases.

Portal hypertension and nodular regenerative hyperplasia in a patient with celiac disease.

Nodular regenerative hyperplasia (NRH) is an uncommon cause of portal hypertension. The disease is often associated with rheumatological or lymphoproliferative disorders. We report the case of a 19-year old patient with celiac disease and portal hypertension. Biopsy of the liver revealed NRH as the underlying cause. There were no signs of autoimmune diseases or defects in the coagulation system that might cause NRH. Celiac disease is often associated with liver abnormalities, but the association with NRH has rarely been described. We discuss the possible relationship of celiac disease and NRH.

Intrahepatic upregulation of RhoA and Rho-kinase signalling contributes to increased hepatic vascular resistance in rats with secondary biliary cirrhosis.

BACKGROUND AND AIMS: Portal hypertension in cirrhosis is mediated in part by increased intrahepatic resistance, reflecting an increased sensitivity of the hepatic microvasculature to vasoconstrictors. Activation of the RhoA/Rho-kinase pathway is essential for contraction of vascular smooth muscle. The aim of this study was to investigate RhoA/Rho-kinase mediated regulation of the intrahepatic vascular tone in cirrhotic rats. METHODS: Cirrhosis was induced by bile duct ligation (BDL). Hepatic RhoA and Rho-kinase expressions were studied by real time reverse transcription polymerase chain reaction and western blot analysis. Hepatic Rho-kinase activity in rat and human livers was assessed as phosphorylation of the Rho-kinase substrate moesin. The effect of the Rho-kinase inhibitor Y-27632 on hepatic perfusion pressure was measured in livers perfused at constant flow. The in vivo effect of intravenous application of Y-27632 was studied by haemodynamic measurements. RESULTS: Hepatic expressions of RhoA and Rho-kinase were increased at mRNA and protein level in BDL rats. Intrahepatic moesin phosphorylation was increased in livers from cirrhotic rats and patients with alcohol induced cirrhosis. Y-27632 reduced the basal perfusion pressure of in situ perfused livers in BDL rats but not in sham operated rats. Y-27632 reduced the sensitivity to methoxamine in isolated perfused livers in sham operated rats more than in BDL rats. In vivo, Y-27632 reduced portal pressure to a greater extent in BDL rats than in sham operated rats. Intrahepatic vascular resistance was decreased in response to bolus injection of Y-27632 in BDL rats but not in sham operated rats. CONCLUSIONS: Upregulation of RhoA and Rho-kinase contributes to increased intrahepatic resistance in cirrhotic rats and to an increased sensitivity of cirrhotic livers to vasoconstrictors.

[Gastrointestinal bleeding in portal hypertension in liver cirrhosis]. / Die intestinale Blutung bei portaler Hypertension bei Leberzirrhose.

There are three major goals in the prophylaxis and treatment of upper gastrointestinal bleeding in portal hypertensive patients: prophylaxis of the first bleeding episode, therapy of active bleeding and prophylaxis of recurrent bleeding. Several therapeutic options are available: non-selective beta-blockers are the treatment of choice in the primary prophylaxis of the first bleeding episode in patients with large esophageal varices. Alternatively, endoscopic band ligation therapy is an option. Acute bleeding varices should be treated by ligation pharmacological and antibiotic therapy. Prophylaxis of recurrent bleeding is patient-dependent: shunt surgery is an option in young patients in a good medical condition (Child-Pugh class A). In patients with refractory ascites and a bilirubin below 3 mg/dl, TIPS is a good option together with recurrent bleeding. At the moment, there are no trials showing that endoscopic ligation therapy is superior to prevent pharmacological therapy. Nevertheless, the first-line treatment in most patients in Germany is endoscopic band ligation. Bleeding from ectopic varices and bleeding from hypertensive gastropathy should be treated individually either by endoscopy, TIPS or drug therapy.

Altered endothelin-1 levels in acute lower limb ischemia and reperfusion.

Tourniquet-induced ischemia is often used in orthopedic and reconstructive procedures. This is associated with muscle damage and dysfunction, which limits tourniquet application time. Endothelin-1 (ET-1) is a potent vasoconstrictor, which has been implicated in ischemic conditions and ischemia-reperfusion injury. This study aimed to investigate the role of ET-1 in human skeletal muscle subjected to tourniquet-induced acute ischemia and reperfusion. Thirteen patients undergoing total knee replacement were studied. Plasma and muscle ET-1 concentrations were measured at the start of surgery, after an hour of acute ischemia, and 15 minutes following reperfusion. ET-1 receptor binding was also studied by use of autoradiography, and ET-1 mRNA expression investigated by use of real-time polymerase chain reaction (RT-PCR). Tissue ET-1 increased following the period of acute ischemia and persisted during reperfusion. ET-1 was associated with microvessels and macrophages in the muscle. No changes in circulating ET-1 levels, ET-1 mRNA expression, or ET-1 receptor binding were found. It is concluded that the ET-1 pathway is involved in acute ischemia and reperfusion and it may contribute to the muscle injury that occurs during surgical procedures.

Vasodilator mRNA levels are increased in the livers of portal hypertensive NO-synthase 3-deficient mice.

BACKGROUND/AIMS: Nitric oxide synthase (NOS) 3-deficient (NOS-3 KO) mice have an increased systemic arterial pressure but develop portal hypertension to the same extent as wildtype (WT) mice. We hypothesized that other vasodilators in the portal circulation compensate for the lack in NOS-3 activity. We used quantitative PCR as a screening method to identify mediators that possibly compensate for NOS-3 in NOS-3 KO mice. METHODS: Mean arterial pressure (MAP) and portal venous pressure (PVP) were measured in the anaesthetized animal. mRNA levels in whole liver tissue were determined by quantitative RT-PCR. RESULTS: NOS-3 KO mice had a significantly higher mean arterial pressure than WT mice, but portal venous pressure did not differ. Bile duct ligation (BDL) induced a drop in MAP and a rise in PVP in both groups. Bile duct ligation induced a significant increase in mRNA levels of the cannabinoid receptor (CB)-1, adrenomedullin and NOS-2 in the liver of NOS-3 KO and WT mice. Nitric oxide synthase-1 and NOS-3 mRNA levels were elevated in BDL WT mice compared with sham-operated WT mice. Higher mRNA levels of CB-1, NOS-1 and the adrenomedullin receptor were found in sham-operated NOS-3 KO mice compared with sham-operated WT mice. CONCLUSIONS: We used quantitative PCR as a screening method to identify vasodilative mediators that might be involved in the compensation for the lack of NOS-3 activity in NOS-3 KO mice. Elevated mRNA levels in sham-operated NOS-3 KO mice compared with sham-operated WT mice were demonstrated for CB-1, NOS-1 and the adrenomedullin receptor.

Spontaneous regression of an inflammatory pseudotumor of the liver.

Inflammatory pseudotumors (IPT) have been described for virtually every site in the body but is rare in the liver. The clinical presentation of hepatic IPT is unspecific, patients complain of fever, malaise, weight loss and often of symptoms related to a mass effect. Routine imaging procedures are not sufficient to make the diagnosis and a biopsy is necessary to differentiate IPT from neoplasms. The course of the disease is unpredictable and in most of the reported cases the patients underwent resection or were medically treated. We report a patient with a histologically proven IPT of the liver that regressed spontaneously over several months without any specific treatment.

Evidence for the involvement of endothelin-1 but not urotensin-II in chronic lower limb ischaemia in man.

BACKGROUND: endogenous vasoconstrictor peptides may play a role in the pathophysiology of critical limb ischaemia (CLI). This study investigated endothelin-1 (ET-1) and urotensin-II (U-II) mRNA expression, peptide distribution and ET receptor subtype binding in chronically ischaemic muscle. METHODS: open muscle biopsies were taken from patients undergoing amputations for CLI and from patients undergoing coronary artery bypass surgery (controls). ET-1 and U-II mRNA expression in muscle biopsies was studied using real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR). ET-1 and U-II immunohistochemistry was performed on muscle sections and ET receptor binding studied using in vitro autoradiography. RESULTS: ET-1 mRNA expression was significantly increased in CLI compared to controls (p<0.05) whilst no significant change in U-II expression occurred. ET-1 immunoreactivity was also increased in CLI with no difference in U-II immunostaining observed. ET(B) receptor binding was significantly increased in CLI (median 4, range 1-8 vs 2, range 1-3, dpm x 10(3)/mm(2), p=0.01, Mann-Whitney test) whilst ET(A) receptor binding was not significantly raised. Binding was associated with microvessels and macrophages. CONCLUSIONS: in CLI, the ET-1 pathway is upregulated but U-II is unaffected. ET-1 may vasoconstrict microvessels and mediate inflammation in chronically ischaemic muscle. ET-1 binding to ET(B) receptors in particular may play an important role in the pathophysiology of CLI underscoring the therapeutic potential of ET(B) receptor antagonists in the management of CLI.

Benign hepatic tumours.

Benign hepatic tumours include a broad spectrum of regenerative and true neoplastic processes. Due to advances in imaging procedures like MRI, Cf-scan and ultrasound as well as progress in immunohistochemistry, the appropriate diagnosis is made ina high percentage of patients without laparotomy and resection. Most important in clinical practice is the differential diagnosis of focal nodular hyperplasia and hepatocellular adenoma because of the risk of rupture and bleeding in the latter. Cavernous haemangioma, the most common benign hepatic tumour, rarely needs treatment. The diagnosis of nodular regenerative hyperplasia is often missed and patients present with secondary complications and signs of portal hypertension that necessitate treatment. The main problem in angiomyolipoma is to distinguish it from malignant processes which do require treatment. Because of its clinical presentation, inflammatory pseudotumour is also sometimes confused with a malignant tumour. Therapeutic options are drug therapy or surgical resection. Benign haemangioendothelioma of the infant is rare but may cause life-threatening complications. Bile duct adenoma is an incidental finding that is not known to cause any symptoms whereas biliary cystadenoma is often symptomatic and may progress to cystadenocarcinoma and therefore needs resection.

Portal hypertension is associated with increased mRNA levels of vasopressor G-protein-coupled receptors in human hepatic arteries.

BACKGROUND: The contractile response of human splanchnic vessels to different vasoconstrictors is attenuated in cirrhosis. Functional studies indicate a cellular signalling defect upstream of the G-protein level. The aim of the present study was to analyze expression and mRNA levels of the following most relevant vasopressor receptors in the smooth musculature of human hepatic arteries: alpha1 adrenoceptor (AR) subtypes a, b and d, angiotensin II type 1 receptor (AT1), arginine vasopressin receptor type 1a (V1a), endothelin receptor type A (ETA) and B (ETB). MATERIALS AND METHODS: Hepatic arteries were collected from 10 donors (noncirrhotic) and 14 recipients (cirrhotic) at liver transplantations. Real-time-PCR was performed to quantify steady-state levels of receptor mRNAs. RESULTS: alpha 1aAR mRNA levels showed no significant difference between the cirrhotic arteries and the controls while the mRNA levels of the other vasoactive receptors were significantly higher in the cirrhotic hepatic arteries (alpha 1bAR: 4-fold, P = 0.013; AT1: 16-fold, P = 0.024; V1a: 23-fold, P = 0.001; ETA: 4-fold, P = 0.02; ETB: 8-fold, P = 0.008). No mRNA for the alpha 1dAR was detected either in the donor or recipient hepatic arteries. CONCLUSION: We conclude that vascular hyporeactivity to the most relevant endogenous vasoconstrictors of cirrhotic hepatic arteries is not caused by a receptor down-regulation at mRNA levels. In contrast they were up-regulated.

Potential role of endothelin 1 in ischaemia-induced angiogenesis in critical leg ischaemia.

BACKGROUND: Ischaemia-induced angiogenesis occurs in critical leg ischaemia (CLI) and endothelin (ET) 1 may be involved in this process. The aim of this study was to quantify microvessels and study ET receptor expression and distribution in critically ischaemic leg muscle. METHODS: Leg muscle biopsies were taken from 12 patients with CLI and 12 patients with no leg ischaemia. Microvessels were identified immunohistochemically on muscle sections, and the number of immunopositive cells was quantified. ETA and ETB receptor messenger RNA (mRNA) expression was studied using real-time quantitative reverse transcriptase-polymerase chain reaction, and receptor binding was localized and assessed by in vitro autoradiography. RESULTS: The number of microvessels in CLI muscle biopsies was 2.6 times higher than that in controls (P < 0.01). ETB receptor mRNA expression and binding were significantly increased in CLI tissue (P < 0.05), while ETA receptor levels were not significantly raised. High-resolution autoradiography showed that ET receptor binding was associated with microvessels. CONCLUSION: Angiogenesis occurs in CLI and raised ETB receptors within the muscle were associated with microvessels, suggesting that ET-1 may mediate angiogenesis via these receptors in critically ischaemic muscle.

[Decreased stimulation of glycosaminoglycan synthesis by human skin fibroblasts by interleukin 6 within the scope of in vitro aging]. / Verminderte Stimulation der Glycosaminoglycansynthese von humanen Hautfibroblasten durch Interleukin-6 im Rahmen der in vitro Alterung.

Addition of human recombinant interleukin 6 (IL-6) to culture medium (supplemented MEM without or with 10% fetal calf serum (FCS)) of human skin fibroblasts exerted a stimulating effect in a dose-dependent manner on glycosaminoglycan (GAG) synthesis, including hyaluronic acid (hyaluronan) synthesis, of young (phase-II) skin fibroblasts in concentrations of 1 ng/ml and 10 ng/ml. Stimulation was mainly due to an increase in extracellular GAGs (secreted into culture medium), and to a lesser extent to an increase in peri- and intracellular GAGs. Stimulation with 1 ng/ml and 10 ng/ml IL-6 led to an increase in hyaluronic acid from 48% to 61% (-FCS) and from 77% to 90% (+10% FCS), respectively. Maximum stimulation, with and without FCS, was achieved by 10 ng/ml IL-6. Compared to young (phase-II) cells, senescent (phase-III) cells, showed no significant stimulation of total GAG (including hyaluronic acid) synthesis by IL-6. The diminished response of GAG- and hyaluronic acid synthesis during aging of these in vitro cultured fibroblasts should motivate further research if similar processes occur during aging in an organism.

Hemodynamic effects of the angiotensin II receptor antagonist irbesartan in patients with cirrhosis and portal hypertension.

BACKGROUND & AIMS: Angiotensin II receptor antagonists have been proposed as new drugs for portal hypertension. This randomized, placebo-controlled, double-blind study aimed to assess the effect of the angiotensin II receptor antagonist irbesartan on portal and systemic hemodynamics and renal function in patients with cirrhosis. METHODS: Thirty-six patients with cirrhosis and portal hypertension received 150 mg/d irbesartan or placebo for 1 week. Systemic hemodynamics, kidney and liver function parameters were recorded regularly; hepatic venous pressure gradient and plasma renin were assessed on days 0 and 7. RESULTS: Irbesartan reduced the hepatic venous pressure gradient by 12.2% +/- 6.6% (P < 0.05) and mean arterial pressure by 5.3% +/- 4.0% in 13 of 18 verum patients. In 4 (22%) verum patients, arterial hypotension, accompanied by significant renal impairment, required withdrawal of irbesartan. In these patients, baseline plasma renin (P < 0.002) and cystatin C (P < 0.001) levels were higher, and creatinine clearance (P < 0.02), serum sodium (P < 0.01), and albumin (P < 0.05) were lower than in patients who tolerated irbesartan. Four of five patients with baseline renin >900 microU/mL developed treatment-limiting hypotension. CONCLUSIONS: The angiotensin II receptor antagonist irbesartan is not advisable in patients with advanced cirrhosis and high plasma renin because it may induce arterial hypotension and only moderately reduces portal pressure.

[Decreased stimulation of glycosaminoglycan synthesis in cultured human skin fibroblasts within the scope of in vitro aging caused by interleukin 1]. / Verminderte Stimulation der Glycosaminoglycansynthese von kultivierten humanen Hautfibroblasten im Rahmen der In-vitro-Alterung durch Interleukin-1.

Addition of human recombinant interleukin-1 (IL-1 alpha or IL-1 beta) to culture medium (supplemented MEM without or with 1%, 10%, or 20% fetal calf serum (FCS)) of human skin fibroblasts exerted a stimulating effect in a dose-dependent manner on glycosaminoglycan (GAG) synthesis, including hyaluronic acid synthesis, of young (Phase II) skin fibroblasts in concentrations of 4, 20, or 100 pg/ml. Stimulation was due to increase in total GAGs, namely extracellular (secreted into culture medium) and cell-bound (pericellular) GAGs. Stimulation with 100 or 200 pg/ml IL-1 beta led to a relative increase (total GAGs: 100%) in hyaluronic acid from 49% to 64 (-FCS) and from 79% to 92% (+10% FCS), respectively. The increase in total GAG synthesis was mainly due to increased synthesis of hyaluronic acid. Maximum stimulation, with and without FCS, was reached by 100 pg/ml IL-1 beta. Compared to young (Phase II) cells senescent (Phase III) cells showed significantly diminished stimulation of hyaluronic acid synthesis by IL-1 beta. Both, IL-1 alpha and IL-1 beta, showed no influence on DNA synthesis. These results suggest that both, IL-1 beta and IL-1 alpha, stimulate GAG and especially hyaluronic acid synthesis, but not DNA synthesis, in vitro. The diminished response of GAG and hyaluronic acid synthesis during ageing of these in vitro cultured fibroblasts gives support to the hypothesis that similar processes might occur during ageing in organisms.