[Transplantation for acute-on-chronic liver failure]. / Transplantation beim akut-auf-chronischen Leberversagen.

A review and discussion of the current literature on liver transplantation for acute-on-chronic liver failure (ACLF) was performed. The ACLF represents an acute deterioration of liver function with pre-existing liver disease and is associated with increasing multiorgan failure, depending on the stage. The 28-day mortality ranges to well over 70% in stage 3 and requires rapid intensive medical treatment involving an interdisciplinary team experienced in transplantation medicine. Under optimized conditions, liver transplantation provides long-term survival rates comparable to other indications. Achieving this requires a differentiated donor selection, choosing the appropriate time for transplantation in the context of a dynamic disease course and the use of appropriate surgical techniques.

Liver stiffness regression after successful Hepatitis C treatment is independent of HIV coinfection.

OBJECTIVES: The aim of the study was to assess the regression of liver stiffness after successful direct-acting antiviral (DAA) treatment in patients with hepatitis C virus (HCV) monoinfection and HCV/-HIV coinfection. In addition, we aimed to identify factors associated with liver stiffness regression. METHODS: We studied patients treated with interferon-free DAA regimens with a sustained virological response at week 12 (SVR12 ) or 24 (SVR24 ) post-treatment. Liver stiffness was assessed by transient elastography (TE) before the initiation and after the end of treatment (median 12 weeks). RESULTS: Of 214 enrolled patients, 85 (40%) were HCV monoinfected and 129 (60%) HCV/HIV coinfected. Baseline median TE values were 7.8 kPa [interquartile range (IQR) 5.9-12.0 kPa] in mono-infected patients and 10.7 kPa (IQR 7.8-17.0 kPa) in coinfected patients. Overall, the median TE value decreased from 10.1 to 6.8 kPa (n = 214; P < 0.0001). There was no difference between mono- and coinfected patients (-2.2 versus -3.3 kPa, respectively; P = 0.88), which was verified by an analysis of covariance (ANCOVA) adjusting for baseline TE values. Significant (≥ 30%) regression of liver stiffness was achieved by 45% of patients (54% with baseline TE ≥ 7.1 kPa). In multivariate analysis, a prior HCV treatment was a negative predictor of liver stiffness regression [odds ratio (OR) 0.31; P = 0.001]. A higher baseline TE value was positively associated with achieving a significant regression (OR 1.06; P = 0.02). HIV coinfection status, HCV genotype, age, sex, treatment duration, controlled attenuation parameter value, bilirubin concentration, platelet count and aspartate aminotransferase concentration were not associated with liver stiffness regression. CONCLUSIONS: Regression of liver stiffness after successful DAA treatment did not differ in patients with HCV monoinfection and those with HCV/HIV coinfection. Half of all patients achieved a significant (≥ 30%) regression. Prior treatment for HCV was a negative predictor for this endpoint, while a higher baseline TE value was positively associated with regression.

Perforin inhibition protects from lethal endothelial damage during fulminant viral hepatitis.

CD8 T cells protect the liver against viral infection, but can also cause severe liver damage that may even lead to organ failure. Given the lack of mechanistic insights and specific treatment options in patients with acute fulminant hepatitis, we develop a mouse model reflecting a severe acute virus-induced CD8 T cell-mediated hepatitis. Here we show that antigen-specific CD8 T cells induce liver damage in a perforin-dependent manner, yet liver failure is not caused by effector responses targeting virus-infected hepatocytes alone. Additionally, CD8 T cell mediated elimination of cross-presenting liver sinusoidal endothelial cells causes endothelial damage that leads to a dramatically impaired sinusoidal perfusion and indirectly to hepatocyte death. With the identification of perforin-mediated killing as a critical pathophysiologic mechanism of liver failure and the protective function of a new class of perforin inhibitor, our study opens new potential therapeutic angles for fulminant viral hepatitis.

[Recent thrombosis of splanchnic veins : Two case reports of catheter-assisted local thrombolysis and thrombus aspiration]. / Frische venöse Thrombose splanchnischer Gefäße : Zwei Fallberichte zur kathetergestützten lokalen Thrombolyse und -aspiration.

Recent non-cirrhotic and non-malignant splanchnic vein thrombosis is now defined as extrahepatic portal vein thrombosis with or without involvement of the mesenteric vein according to the Baveno VI consensus from 2015. An early diagnosis is often challenging due to unspecific symptoms with abdominal pain or diarrhea but extremely important because of the potential acute and chronic complications, such as mesenteric ischemia and portal hypertension; therefore, rapid treatment is crucial. We present two cases of severe splanchnic vein thrombosis, which were treated with catheter-directed local thrombolysis and thrombus aspiration. These minimally invasive catheter-directed techniques have recently been successfully used in selected patients. A review of the literature is provided in this article. In summary, the management of splanchnic vein thrombosis must be individually planned for each patient and should be performed at experienced centers, which can provide all therapeutic options. In selected cases with the correct indications transjugular transhepatic catheter-directed local thrombolysis is a safe option with a good outcome.

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.

Circulating Elastin Fragments Are Not Affected by Hepatic, Renal and Hemodynamic Changes, But Reflect Survival in Cirrhosis with TIPS.

BACKGROUND AND AIMS: Progressive fibrosis increases hepatic resistance and causes portal hypertension with complications. During progressive fibrosis remodeling and deposition of collagens and elastin occur. Elastin remodeling is crucially involved in fibrosis progression in animal models and human data. This study investigated the association of circulating elastin with the clinical outcome in cirrhotic patients with severe portal hypertension receiving transjugular intrahepatic porto-systemic shunt (TIPS). METHODS: We analyzed portal and hepatic venous samples of 110 cirrhotic patients obtained at TIPS insertion and 2 weeks later. The circulating levels of elastin fragments (ELM) were determined using specific monoclonal ELISA. The relationship of ELM with clinical short-time follow-up and long-term outcome was investigated. RESULTS: Circulating levels of ELM showed a gradient across the liver before TIPS with higher levels in the hepatic vein. Interestingly, the circulating ELM levels remained unchanged after TIPS. The circulating levels of ELM in portal and hepatic veins correlated with platelet counts and inversely with serum sodium. Hepatic venous levels of ELM were higher in CHILD C compared to CHILD A and B and were associated with the presence of ascites. Patients with high levels of ELM in the hepatic veins before TIPS showed poorer survival. In multivariate analysis ELM levels in the hepatic veins and MELD were independent predictors of mortality in these patients. CONCLUSION: This study demonstrated that circulating levels of ELM are not associated with hemodynamic changes, but might reflect fibrosis remodeling and predict survival in patients with severe portal hypertension receiving TIPS independently of MELD.

The carbon tetrachloride model in mice.

Recently, the need for more standardized operation procedures in experimental liver fibrosis research was suggested due to dramatic changes in European animal welfare rules. Here, we present a short series of standard operation procedures (SOPs) summarizing the most relevant and widely accepted experimental models for the induction of liver injury leading to liver fibrosis. The described procedures are based on the long-term experience of the Collaborative Research Centre 'Organ Fibrosis: From Mechanisms of Injury to Modulation of Disease' (http://www.sfbtrr57.rwth-aachen.de/), which is supported by the German Research Foundation (SFB/TRR57). These SOPs will help to improve standardization of fibrosis models and to increase the comparability of data between different laboratories with the aim of reducing animal experimentation according to the principle that was proposed in 1959 by Russell and Burch as an ethical framework for conducting scientific experiments with animals, namely the replacement, refinement and reduction (3R) principle. In the first section we focus on the carbon tetrachloride (CCl4) model in mice, which is the toxic model of liver fibrosis induction most commonly used worldwide.

Mouse models of metabolic liver injury.

Metabolic liver injury is one of the fastest growing health problems worldwide. Alcoholic and non-alcoholic fatty livers have been shown to be associated with progression to end-stage liver diseases, as well as to liver cancers, in humans. More importantly, there are no validated therapies for these disorders, therefore intensive research is required in this area. This review of standard operation procedures focuses on the experimental models of fatty liver disease in the mouse. Firstly, use of these experimental models might improve understanding of underlying mechanisms, and secondly this might help to test potential therapeutic options. This article includes, besides a short historic background, an insight into the pathobiochemical mechanisms and detailed experimental procedures as well as the practical implementation of these models.

Novel serological neo-epitope markers of extracellular matrix proteins for the detection of portal hypertension.

BACKGROUND: The hepatic venous pressure gradient (HVPG) is an invasive, but important diagnostic and prognostic marker in cirrhosis with portal hypertension (PHT). During cirrhosis, remodelling of fibrotic tissue by matrix metalloproteinases (MMPs) is a permanent process generating small fragments of degraded extracellular matrix (ECM) proteins known as neoepitopes, which are then released into the circulation. AIM: To investigate their potential as plasma markers for detection of PHT. METHODS: Ninety-four patients with alcoholic cirrhosis and 20 liver-healthy controls were included. Clinical and laboratory data of the patients were collected. All patients received HVPG measurement with blood sampling. In these samples, the following degradation or formation markers were measured: C1M (type I-collagen), C3M and PRO-C3 (type III collagen), C4M and P4NP 7S (type IV collagen), C5M (type V collagen), C6M (type VI collagen), BGM (biglycan), ELM (elastin), CRPM (CRP). RESULTS: All ECM markers except for CRPM correlated significantly with HVPG. Interestingly, C4M, C5M and ELM levels were significantly higher in patients with HVPG >10 mmHg. Multiple regression analysis identified PRO-C3, C6M and ELM as significant determinants, while the models A and B including PRO-C3, ELM, C6M and model for end-stage liver disease (MELD) provided better description of PHT (r = 0.75, P < 0.0001). The models provided odds ratios of >100 for having clinical significant PHT. CONCLUSIONS: These novel non-invasive extracellular matrix markers reflect the degree of liver dysfunction. The different degrees of portal hypertension correlated with these circulating neoepitopes. Using a single blood sample, these neoepitopes in combination with MELD detect the level of portal hypertension.

Physical activity of predialysis patients with chronic kidney disease measured using SenseWear Armban.

AIM: The aim of the study was to analyze the correlations between age, BMI, fat mass, muscle mass, GFR and factors related to physical activity (PA) of predialysis individuals with chronic kidney disease (CKD). METHODS: Into the study were enrolled 24 predialysis CKD patients: 6 male, 18 female (mean age 60.3 ± 10.2 years, BMI 27.5 ± 4.5 kg/m2, GFR 17.67 ± 6.52 mL/min/1.73 m2). PA was assessed during 24-hours using the multisensor system Armband SenseWear Pro 3. Body composition (BC) was measured using bioimpedance. RESULTS: Total energy expenditure was 32.4±5.8 kcal/kg of body mass. Number of steps was 10423 ± 3680/day. Average lying down duration was 527 ± 107 min, median of physical activity duration was 74 min. All analyzed factors, except sleep duration, were dependent on the age. Fat mass and muscle mass were correlated with total energy expenditure (respectively r=-0.59, P=0.003; r=0.56, P=0.005), lying down duration (r=0.43, P=0.030; r=-0.52, P=0.009), physical activity duration (r=-0.53, P=0.008; r=0.56, P=0.004). GFR was correlated with lying down duration (r=-0.42, P=0.046). CONCLUSION: PA of CKD patients was satisfactory - all patients demonstrated PA duration higher than 40 min. No influence of gender on the level of PA was observed, but PA decreased with the age progress. Higher level of PA was connected with favourable BC. The GFR level in the observed patients did not influence PA, except lying down duration, which was longer in patients with lower GFR.

Vascular hyporesponsiveness to angiotensin II in rats with CCl(4)-induced liver cirrhosis.

BACKGROUND: Portal hypertension is triggered by vasodilation due to impaired contraction of extrahepatic vessels. Angiotensin II type 1 (AT(1)) receptor-induced vasocontraction is mediated by G proteins and may be desensitized by recruitment of beta-arrestin-2 to the receptor. In this study, we analysed the interaction of AT(1) receptors with beta-arrestin-2 in the context of vascular hypocontractility in rats with CCl(4)-induced cirrhosis. METHODS: Micronodular liver cirrhosis in rats (n = 15) was induced by regular CCl(4) exposure. Age-matched rats (n = 15) served as controls. Contractility of aortic rings was measured by myography. Protein expressions and phosphorylations were assessed by Western blot analysis, and AT(1) receptor interaction with beta-arrestin-2 by co-immunoprecipitation. RESULTS: Aortic rings from CCl(4) rats were hypocontractile to angiotensin II independent of nitric oxide synthases (Nomega-nitro-l-arginine methyl ester 200 microM). Expression of the AT(1) receptor, Galpha(q/11) and the contraction-mediating effector Rho kinase was similar in aortas from both groups. Expression and AT(1) receptor binding of beta-arrestin-2 were up-regulated in aortas from CCl(4) rats. Stimulation of isolated aortas with exogenous angiotensin II caused recruitment of beta-arrestin-2 in aortas from noncirrhotic rats, but no further interaction of AT(1) receptors with beta-arrestin-2 was found in aortas from CCl(4) rats. While angiotensin II stimulation resulted in Rho kinase activation in aortas from noncirrhotic rats but not in aortas from CCl(4) rats, extracellular signal-regulated kinase activation in response to angiotensin II was observed in aortas from both groups. CONCLUSIONS: Vascular hyporesponsiveness to angiotensin II in CCl(4) rats is due to enhanced interaction of the AT(1) receptor with beta-arrestin-2 and consecutively changed receptor function.

Sorafenib targets dysregulated Rho kinase expression and portal hypertension in rats with secondary biliary cirrhosis.

BACKGROUND AND PURPOSE: Extrahepatic vasodilation and increased intrahepatic vascular resistance represent attractive targets for the medical treatment of portal hypertension in liver cirrhosis. In both dysfunctions, dysregulation of the contraction-mediating Rho kinase plays an important role as it contributes to altered vasoconstrictor responsiveness. However, the mechanisms of vascular Rho kinase dysregulation in cirrhosis are insufficiently understood. They possibly involve mitogen-activated protein kinase/extracellular signal-regulated kinase (ERK)-dependent mechanisms in extrahepatic vessels. As the multikinase inhibitor sorafenib inhibits ERK, we tested the effect of sorafenib on haemodynamics and dysregulated vascular Rho kinase in rats with secondary biliary cirrhosis. EXPERIMENTAL APPROACH: Secondary biliary cirrhosis was induced by bile duct ligation (BDL). Sorafenib was given orally for 1 week (60 mg.kg(-1).d(-1)). Messenger RNA levels were determined by quantitative real time polymerase chain reaction, protein expressions and protein phosphorylation by Western blot analysis. Aortic contractility was studied by myographic measurements, and intrahepatic vasoregulation by using livers perfused in situ. In vivo, haemodynamic parameters were assessed invasively in combination with coloured microspheres. KEY RESULTS: In BDL rats, treatment with sorafenib decreased portal pressure, paralleled by decreases in hepatic Rho kinase expression and Rho kinase-mediated intrahepatic vascular resistance. In aortas from BDL rats, sorafenib caused up-regulation of Rho kinase and an improvement of aortic contractility. By contrast, mesenteric Rho kinase remained unaffected by sorafenib. CONCLUSIONS AND IMPLICATIONS: Intrahepatic dysregulation of vascular Rho kinase expression is controlled by sorafenib-sensitive mechanisms in rats with secondary biliary cirrhosis. Thus, sorafenib reduced portal pressure without affecting systemic blood pressure.

Mechanisms of extrahepatic vasodilation in portal hypertension.

In liver cirrhosis, abnormal persistent extrahepatic vasodilation leads to hyperdynamic circulatory dysfunction which essentially contributes to portal hypertension. Since portal hypertension is a major factor in the development of complications in cirrhosis, the mechanisms underlying this vasodilation are of paramount interest. Extensive studies performed in cirrhotic patients and animals revealed that this vasodilation is associated on the one hand with enhanced formation of vasodilators, and on the other hand with vascular hyporesponsiveness to vasoconstrictors. The latter phenomenon has been termed "vascular hypocontractility". It is caused by a combination of different mechanisms and factors described in this review.

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.

Acute haemodynamic effects of losartan in anaesthetized cirrhotic rats.

BACKGROUND: Portal hypertension in cirrhosis is the result of increased intrahepatic vascular resistance to portal outflow as well as increased portal tributary blood flow. The angiotensin II type 1 receptor antagonist losartan has been suggested as a portal pressure-lowering drug in patients with cirrhosis. AIM: To investigate the systemic and splanchnic haemodynamic effects of different doses of losartan. METHODS: In 35 anaesthetized rats with secondary biliary cirrhosis, 3, 10 or 30 mg of losartan kg(-1) or solvent were administered intravenously. Ten sham-operated rats served as controls. Mean arterial pressure and portal pressure were measured by catheters in the femoral artery or portal vein. Systemic and splanchnic haemodynamics and mesenterico-systemic shunt rate were determined by the coloured microsphere method. RESULTS: Losartan reduced portal pressure (sham: 9.1 +/- 0.4. cirrhosis: 19.3 +/- 1.1, after 3 mg kg(-1) of losartan 16.4 +/- 0.4, after 10 mg kg(-1) of losartan 15.6 +/- 0.6, after 30 mg kg(-1) of losartan 14.9 +/- 0.6 mmHg) without reducing portal sinusoidal resistance. However, in cirrhotic rats it reduced portal tributary blood flow (sham: 4.3 +/- 0.6. cirrhosis: 8.6 +/- 1.4, after 3 mg kg(-1) of losartan 3.8 +/- 0.7, after 10 mg kg(-1) of losartan 4.7 +/- 0.5, after 30 mg kg(-1) of losartan 5.9 +/- 0.9 mmHg). This was owing either to an increase in splanchnic vascular resistance at the 3 mg kg(-1) dose or to a reduction in the splanchnic perfusion-pressure gradient secondary to a reduction in mean arterial pressure at the 10 and 30 mg kg(-1) doses (mean arterial pressure: sham: 109.7 +/- 4.8. cirrhosis: 109.4 +/- 2.8, after 3 mg kg(-1) of losartan 99.7 +/- 2.9, after 10 mg kg(-1) of losartan 89.9 +/- 3.4, after 30 mg kg(-1) of losartan 81.0 +/- 2.9 mmHg). CONCLUSIONS: Low doses of losartan reduce portal hypertension by an increase in splanchnic vascular resistance without hypotensive side-effects on arterial pressure.

[Antibiotic-resistant cystitis in the course of urinary bladder calculi after vesicoureteral reflux operation many years ago]. / Oporne na leczenie przeciwbakteryjne zapalenie pecherza moczowego w przebiegu kamicy u osoby po operacji odplywu pecherzowo-moczowodowego przed laty.

This is the introduction of chronic cystitis in course of urinary bladder calculi, 12 years after vesicoureteral reflux operation. The nucleus of the calculus (3 x 3 x 4 cm) were unresorbed dexon sutures left after the surgical treatment. Inaccuracy of radiological and ultrasonography examination delayed the settlement of the diagnosis about 18 months, and patient was caused of many months antibacterial therapy. After removal the calculus from the urinary bladder, dysuric disorders abated quickly and than after 8 weeks antibacterial therapy pathological changes in urine analysis disappeared, urine culture was sterile.

[Effect of hemodialysis on the level of serum digoxin-like substance and sodium-potassium pump activity in erythrocytes from patients with chronic renal failure]. / Wplyw hemodializy na stezenie substancji digoksynopodobnej w surowicy krwi i aktywnosc pompy sodowo-potasowej w erytrocytach chorych z przewlekla niewydolnoscia nerek.

Digoxin-like immunoreactivity (DLS) and erythrocyte sodium-potassium pump (PSP) activity were measured in a group of 16 patients with chronic renal failure (CRF) before and just after haemodialysis and in a group of 9 healthy persons. Before haemodialysis DLS was present in the blood of most CRF patients, at the mean concentration of 0,14 +/- 0,13 micrograms/l. After haemodialysis DLS concentration decreased to 0,09 +/- 0,09 microgram/l (p less than 0,01). In the control group blood DLS concentration was nondetectable. In the CRF group PSP activity was higher before than after haemodialysis (p less than 0,01; 12,1 +/- 1,8 and 7,6 +/- 1,4 muMol Pi/h/g Hb. PSP activity in the control groups was 10,3 +/- 1,9 muMol Pi/h/g Hb). In the CRF group PSP activity was higher before haemodialysis (p less than 0,05) and lower after haemodialysis (p less than 0.01) than in the control group. Our results confirmed the presence of DLS in the blood of the majority of CRF patients. DLS concentration decreased after haemodialysis but we did not found any parallel increase in PSP activity in these patients. These results did not confirm the hypothesis that DLS might inhibit PSP activity in red blood cells from CRF patients.