The management of iron deficiency in inflammatory bowel disease--an online tool developed by the RAND/UCLA appropriateness method

BACKGROUND

Iron deficiency is a common and undertreated problem in inflammatory bowel disease (IBD).

AIM

To develop an online tool to support treatment choice at the patient-specific level.

METHODS

Using the RAND/UCLA Appropriateness Method (RUAM), a European expert panel assessed the appropriateness of treatment regimens for a variety of clinical scenarios in patients with non-anaemic iron deficiency (NAID) and iron deficiency anaemia (IDA). Treatment options included adjustment of IBD medication only, oral iron supplementation, high-/low-dose intravenous (IV) regimens, IV iron plus erythropoietin-stimulating agent (ESA), and blood transfusion. The panel process consisted of two individual rating rounds (1148 treatment indications; 9-point scale) and three plenary discussion meetings.

RESULTS

The panel reached agreement on 71% of treatment indications. 'No treatment' was never considered appropriate, and repeat treatment after previous failure was generally discouraged. For 98% of scenarios, at least one treatment was appropriate. Adjustment of IBD medication was deemed appropriate in all patients with active disease. Use of oral iron was mainly considered an option in NAID and mildly anaemic patients without disease activity. IV regimens were often judged appropriate, with high-dose IV iron being the preferred option in 77% of IDA scenarios. Blood transfusion and IV+ESA were indicated in exceptional cases only.

CONCLUSIONS

The RUAM revealed high agreement amongst experts on the management of iron deficiency in patients with IBD. High-dose IV iron was more often considered appropriate than other options. To facilitate dissemination of the recommendations, panel outcomes were embedded in an online tool, accessible via http://ferroscope.com/.

Impaired endothelial nitric oxide synthase activity associated with enhanced caveolin binding in experimental cirrhosis in the rat

BACKGROUND & AIMS

A reduction in nitric oxide (NO) has been implicated as a cause of intrahepatic vasoconstriction in cirrhosis, but the regulatory mechanisms remain undefined. The aim of this study was to examine a contributory role for caveolin-1, a putative negative regulator of endothelial NO synthase, in mediating deficient intrahepatic NO production in the intact cirrhotic liver.

METHODS

Cirrhosis was induced by carbon tetrachloride inhalation. Flow regulation of NO production and perfusion pressure was examined in the perfused rat liver. Protein expression of endothelial NO synthase (eNOS), caveolin, and calmodulin was examined by Western blotting and immunohistochemistry. NOS activity and NO production were assessed by citrulline generation and chemiluminescence, respectively. Protein-protein interactions were examined using whole tissue protein immunoprecipitation.

RESULTS

In response to incremental increases in flow, cirrhotic animals produced significantly less NO(x) than control animals. NOS activity was significantly reduced in liver tissue from cirrhotic animals compared with control animals in the presence of similar eNOS protein levels. Deficient eNOS activity was associated with a severalfold increase in binding of eNOS with caveolin. Protein levels of caveolin-1 were markedly increased in the cirrhotic liver.

CONCLUSIONS

These studies provide evidence that enhanced expression and interaction of caveolin with eNOS contribute to impaired NO production, reduced NOS activity, and vasoconstriction in the intact cirrhotic liver.

Endothelial dysfunction and decreased production of nitric oxide in the intrahepatic microcirculation of cirrhotic rats

Increased intrahepatic resistance in cirrhotic livers is in part caused by increased vascular tone. Several morphological abnormalities have been described in the sinusoidal endothelial cells of cirrhotic livers, but the functional impact of these abnormalities on the intrahepatic vascular tone has not been studied. The aim of this study was to investigate the intrahepatic endothelial function and the role of nitric oxide (NO) with regard to vascular tone in cirrhotic livers. Isolated rat liver perfusions were performed in cirrhotic rats (induced by chronic carbon tetrachloride inhalation) and weight-matched normal controls. After preconstricting the intrahepatic microcirculation with methoxamine (10(-4) mol/L), response to cumulative doses of receptor-mediated endothelial agonist, acetylcholine (10(-7) mol/L-10(-5) mol/L), was obtained. In another series, response to the receptor-independent endothelial agonist, calcium ionophore A23187 (10(-7) mol/L and 3 x 10(-7) mol/L), was obtained in the absence and presence of Nomega-nitro-L-arginine (NNA) and indomethacin. In a third series of rats, nitrate and nitrite production was measured in the perfusate of perfused normal and cirrhotic livers. There was significantly less vasorelaxation in cirrhotic livers as compared with normal livers in response to acetylcholine and calcium ionophore A23187 (P < .0001). The impaired vasorelaxation was a result of a decrease in both NO-mediated and non-NO-mediated components of vasorelaxation. Cirrhotic livers from ascitic rats had significantly less vasorelaxation as compared with livers from nonascitic rats (P < .005). There was significantly less production of nitrates and nitrites in cirrhotic livers (P < .05). The liver microcirculation of cirrhotic livers is characterized by endothelial dysfunction that results in impaired release of endothelial relaxing factors including NO.