Hepatopulmonary syndrome is associated with low sphingosine-1-phosphate levels and can be ameliorated by the functional agonist fingolimod.

BACKGROUND & AIMS: Hepatopulmonary syndrome (HPS) is characterised by a defect in arterial oxygenation induced by pulmonary vascular dilatation in patients with liver disease. Fingolimod, a sphingosine-1-phosphate (S1P) receptor modulator, suppresses vasodilation by reducing nitric oxide (NO) production. We investigated the role of S1P in patients with HPS and the role of fingolimod as a therapeutic option in an experimental model of HPS. METHODS: Patients with cirrhosis with HPS (n = 44) and without HPS (n = 89) and 25 healthy controls were studied. Plasma levels of S1P, NO, and markers of systemic inflammation were studied. In a murine model of common bile duct ligation (CBDL), variations in pulmonary vasculature, arterial oxygenation, liver fibrosis, and inflammation were estimated before and after administration of S1P and fingolimod. RESULTS: Log of plasma S1P levels was significantly lower in patients with HPS than in those without HPS (3.1 ± 1.4 vs. 4.6 ± 0.2; p <0.001) and more so in severe intrapulmonary shunting than in mild and moderate intrapulmonary shunting (p <0.001). Plasma tumour necrosis factor-α (76.5 [30.3-91.6] vs. 52.9 [25.2-82.8]; p = 0.02) and NO (152.9 ± 41.2 vs. 79.2 ± 29.2; p = 0.001) levels were higher in patients with HPS than in those without HPS. An increase in Th17 (p <0.001) and T regulatory cells (p <0.001) was observed; the latter inversely correlated with plasma S1P levels. In the CBDL HPS model, fingolimod restored pulmonary vascular injury by increasing the arterial blood gas exchange and reducing systemic and pulmonary inflammation, resulting in improved survival (p = 0.02). Compared with vehicle treatment, fingolimod reduced portal pressure (p <0.05) and hepatic fibrosis and improved hepatocyte proliferation. It also induced apoptotic death in hepatic stellate cells and reduced collagen formation. CONCLUSIONS: Plasma S1P levels are low in patients with HPS and even more so in severe cases. Fingolimod, by improving pulmonary vascular tone and oxygenation, improves survival in a murine CBDL HPS model. IMPACT AND IMPLICATIONS: A low level of plasma sphingosine-1-phosphate (S1P) is associated with severe pulmonary vascular shunting, and hence, it can serve as a marker of disease severity in patients with hepatopulmonary syndrome (HPS). Fingolimod, a functional agonist of S1P, reduces hepatic inflammation, improves vascular tone, and thus retards the progression of fibrosis in a preclinical animal model of HPS. Fingolimod is being proposed as a potential novel therapy for management of patients with HPS.

Tolerance of standard dose albumin infused over 6 hrs for treatment of spontaneous bacterial peritonitis-A randomized controlled trial.

BACKGROUND AND AIMS: Twenty per cent albumin (1.5 g/kg at diagnosis and 1 g/kg on day three, infused over six-hour duration) is recommended particularly in high-risk spontaneous bacterial peritonitis (SBP). Whether reduced dose albumin infusion is as effective as the standard dose albumin infusion is not clear. The aim of this study was to compare standard dose albumin infusion with reduced dose albumin infusion in acute kidney injury (AKI) development or progression in patients with cirrhosis and high-risk SBP. METHODS: Sixty-three patients were randomized to the standard dose albumin arm (n = 31) and reduced dose albumin arm (n = 32, 0.75 g/kg at diagnosis and 0.5 g/kg 48 h later). The albumin was infused over six-hour duration in both groups. When the patient developed respiratory distress, the albumin infusion was stopped and that dose (i.e. of day one or day three) was not restarted and no attempt was made to finish the whole dose of that day. However, the next dose was started at the pre-calculated infusion rate if there was no evidence of respiratory distress at the start of next infusion. RESULTS: All 31 patients in standard dose and two (6.25%) in the reduced dose group developed symptomatic circulatory overload (p < 0.001), with infusions being stopped prematurely. The actual albumin dose received on day one was similar in both groups and only slightly higher in the standard dose group on day three. Resolution of SBP, progression of AKI to higher stage, in-hospital mortality and 28 days' mortality were similar in both groups. CONCLUSIONS: For treatment of SBP, standard dose albumin infusion (1.5 g/kg at diagnosis and 1 g/kg 48 hours later) infused over six hours is not tolerated by Indian patients. The effectiveness of standard dose albumin infused over more prolonged periods, as compared to reduced dose albumin, should be evaluated in further studies. TRIAL REGISTRATION: Clinical Trials.gov Identifier: NCT04273373 .

Natural history, risk factors, and outcome of hepatopulmonary syndrome in pediatric liver diseases.

BACKGROUND: Limited pediatric literature is available regarding hepatopulmonary syndrome (HPS) especially in subjects with biliary atresia (BA) despite its proven prognostic significance. Thus, we aimed to study the natural history, risk factors, and outcome of HPS in BA and other chronic liver disease (CLD) subjects. METHODS: All children (BA and other non-BA CLDs) older than 6 months of age were included in the study. HPS was diagnosed on the basis of standard international criteria. Also, fractional exhaled nitric oxide (FeNO) was measured at baseline. RESULTS: During the study period from January 2017 to December 2018, there were 42 children in BA and 62 in the CLD group. The overall prevalence of HPS was 42.3%: 57.1% in the BA group and 32.2% in the CLD group. Median age at HPS diagnosis was 14.4 months and 90 months in the BA and non-BA CLD groups, respectively. By the end of study period, the prevalence of HPS in the BA group further increased to 73.8% at 0.7% per month. Lower serum albumin (p < 0.05) in BA and higher splenic Z scores (p 0.013) in other CLDs were found to be significant risk factors for HPS. FeNO measurement did not reach diagnostic significance. CONCLUSION: Prevalence of HPS is higher and also develops at an earlier age in the BA group compared to other CLDs. Also, risk of HPS development increases with increasing disease duration in BA. Lower serum albumin in BA and higher splenic Z scores in other CLDs may predict risk for HPS development.

Antioxidant status in rheumatoid arthritis and role of antioxidant therapy.

BACKGROUND: Oxygen free radicals have been implicated as mediators of tissue damage in patients of rheumatoid arthritis (RA). This study was designed to elucidate plasma oxidant/antioxidant status in rheumatoid arthritis, with the aim of evaluating the importance of antioxidant therapy in the management of this disease. METHODS: The study included 40 patients of rheumatoid arthritis who were randomly divided into two subgroups of 20 each. One group received conventional treatment for 12 weeks and in the other group conventional treatment was supplemented with antioxidants for the same duration. Twenty age- and sex-matched normal individuals constituted the control group. Blood samples of controls and patients were collected at the time of presentation and analyzed for total thiols, glutathione, vitamin C and malondialdehyde (MDA-marker of oxidative stress). The investigations were repeated in the patients after 12 weeks. RESULTS: The blood concentrations of total thiols, glutathione and vitamin C were found to be significantly lower in rheumatoid arthritis patients as compared to healthy controls, while the concentrations of MDA were much higher. There was a statistically significant increase in the posttreatment concentrations of these antioxidants, along with a decrease in the concentrations of MDA. CONCLUSIONS: The antioxidant defense system is compromised in rheumatoid arthritis patients. There is a shift in the oxidant/antioxidant balance in favor of lipid peroxidation, which could lead to the tissue damage observed in the disease. The results suggest the necessity for therapeutic co-administration of antioxidants along with conventional drugs to such patients. However, due to the limited number of cases included in this study, more studies may be required to substantiate the results and arrive at a definite conclusion, in terms of safety and efficacy of adding on antioxidant therapy for the treatment of RA.