Matthew J. Brookes

Effects of allogeneic red blood cell transfusions on clinical outcomes in patients undergoing colorectal cancer surgery: a systematic review and meta-analysis.

Objective:To determine the effect of allogeneic blood transfusion (ABT) on clinical outcomes in patients with colorectal cancer undergoing surgery. Background:Perioperative ABTs may be associated with adverse clinical outcomes. Methods:Systematic review of the literature with odds ratio (OR) and incidence rate ratio (IRR) meta-analyses of predefined clinical outcomes based on a MEDLINE search. Results:In total, 20,795 colorectal cancer (CRC) patients observed for more than 59.2 ± 26.1 months (108,838 patient years) were included, of which 58.8% were transfused. ABT was associated with increased all-cause mortality OR = 1.72 (95% confidence interval [CI] 1.55 − 1.91, P < 0.001); I2 = 23.3% (0 − 51.1) and IRR = 1.31 (1.23 − 1.39, P < 0.001), I2 = 0.0% (0 − 37.0). ABT was also associated with increased ORs (95% CI, P) for cancer-related mortality of 1.71 (1.43 − 2.05, P <0.001), combined recurrence—metastasis—death 1.66 (1.41 − 1.97, P < 0.001), postoperative infection 3.27 (2.05 − 5.20, P < 0.001), and surgical reintervention 4.08 (2.18 − 7.62, <0.001). IRR (95% CI, P) was 1.45 (1.26 − 1.66, <0.001) for cancer-related mortality and 1.32 (1.19 − 1.46, <0.001) for recurrence—metastasis—death. Mean length of hospital stay was significantly longer in transfused compared with nontransfused patients (17.8 ± 4.8 vs 13.9 ± 4.7 days, P = 0.005). Conclusions:In patients with colorectal cancer (CRC) undergoing surgery, ABTs are associated with adverse clinical outcomes, including increased mortality. Measures aimed at limiting the use of ABTs should be investigated further.

Modulation of iron transport proteins in human colorectal carcinogenesis

Background and aims: Total body iron and high dietary iron intake are risk factors for colorectal cancer. To date there is no comprehensive characterisation of iron transport proteins in progression to colorectal carcinoma. In this study, we examined expression of iron import (duodenal cytochrome b (DCYTB), divalent metal transporter 1 (DMT1), and transferrin receptor 1 (TfR1)) and export (hephaestin (HEPH) and ferroportin (FPN)) proteins in colorectal carcinoma. Methods: Perl’s staining was used to examine colonocyte iron content. Real time polymerase chain reaction (PCR) and western blotting were used to examine mRNA and protein levels of the molecules of interest in 11 human colorectal cancers. Semiquantitative immunohistochemistry was used to verify protein levels and information on cellular localisation. The effect of iron loading on E-cadherin expression in SW480 and Caco-2 cell lines was examined by promoter assays, real time PCR and western blotting. Results: Perl’s staining showed increased iron in colorectal cancers, and there was a corresponding overexpression of components of the intracellular iron import machinery (DCYTB, DMT1, and TfR1). The iron exporter FPN was also overexpressed, but its intracellular location, combined with reduced HEPH levels, suggests reduced iron efflux in the majority of colorectal cancers examined. Loss of HEPH and FPN expression was associated with more advanced disease. Iron loading Caco-2 and SW480 cells caused cellular proliferation and E-cadherin repression. Conclusions: Progression to colorectal cancer is associated with increased expression in iron import proteins and a block in iron export due to decreased expression and aberrant localisation of HEPH and FPN, respectively. This results in increased intracellular iron which may induce proliferation and repress cell adhesion.

A role for iron in Wnt signalling

There is an emerging body of evidence implicating iron in carcinogenesis and in particular colorectal cancer, but whether this involves Wnt signalling, a major oncogenic signalling pathway has not been studied. We aimed to determine the effect of iron loading on Wnt signalling using mutant APC (Caco-2 and SW480) and wild-type APC (HEK-293 and human primary fibroblasts) containing cell lines. Elevating cellular iron levels in Caco-2 and SW480 cells caused increased Wnt signalling as indicated by increased TOPFLASH reporter activity, increased mRNA expression of two known targets, c-myc and Nkd1, and increased cellular proliferation. In contrast wild-type APC and β-catenin-containing lines, HEK 293 and human primary fibroblasts were not responsive to iron loading. This was verified in SW480 cells that no longer induced iron-mediated Wnt signalling when transfected with wild-type APC. The cell line LS174T, wild type for APC but mutant for β-catenin, was also responsive suggesting that the role of iron is to regulate β-catenin. Furthermore, we show that E-cadherin status has no influence on iron-mediated Wnt signalling. We thus speculate that excess iron could exacerbate tumorigenesis in the background of APC loss, a common finding in cancers.

Luminal Iron Levels Govern Intestinal Tumorigenesis after Apc Loss In Vivo

It is clear from epidemiological studies that excess iron is associated with increased risk of colorectal cancer; however, questions regarding the mechanism of how iron increases cancer risk, the source of the excess iron (circulating or luminal), and whether iron reduction represents a potential therapeutic option remain unanswered. In this study, we show that after Apc deletion, the cellular iron acquisition proteins TfR1 and DMT1 are rapidly induced. Conversely, restoration of APC reduces cellular iron due to repression of these proteins. To test the functional importance of these findings, we performed in vivo investigations of the impact of iron levels on intestinal tumorigenesis. Strikingly, depletion of luminal (but not systemic) iron strongly suppressed murine intestinal tumorigenesis, whereas increased luminal iron strongly promoted tumorigenesis. Taken together, our data definitively delineate iron as a potent modifier of intestinal tumorigenesis and have important implications for dietary iron supplementation in patients at high risk of colorectal cancer.

Between-assay variability of faecal calprotectin enzyme-linked immunosorbent assay kits

Background Faecal calprotectin (f-Cp), a marker of intestinal inflammation, can be used to distinguish between functional and organic bowel disease. F-Cp, following extraction, is commonly quantified using enzyme-linked immunosorbent assays (ELISAs) but there are no data comparing the different f-Cp assays or sample extraction devices. We, therefore, evaluated and compared the performance of the Immunodiagnostik, Bühlmann and Eurospital f-Cp ELISA assays as well as the Roche, Immunodiagnostik and ScheBo Biotech commercial faecal extraction devices. We also briefly report results from a pilot f-Cp external quality assurance (EQA) scheme. Methods Imprecision, linearity, recovery, drift and limit of quantitation of the f-Cp assays were evaluated and between-assay variability assessed. The three commercial sample extraction devices were compared with the manual weighing method. Four faecal samples were distributed as part of a pilot EQA scheme to 15 laboratories using quantitative ELISA f-Cp assays. Results The three f-Cp assays demonstrated adequate intra-/interbatch imprecision, linearity and recovery. The crosscomparison study and EQA data demonstrated that, for the same sample, the Bühlmann assay reports up to 3.8 times higher f-Cp concentrations than the Immunodiagnostik and Eurospital assays. On average, the commercial extraction devices led to a 7.8-28.1% under-recovery of f-Cp in comparison to the manual weighing method. Conclusions Laboratories should be aware of the lack of the assay standardization, as demonstrated by the between-assay variability. A comparison between f-Cp concentrations reported by these assays and clinical markers of disease severity is required in order to determine their diagnostic accuracy. The EQA scheme represents the first available programme for f-Cp.

A role for tumour necrosis factor α in human small bowel iron transport

Cytokines are integral to the development of anaemia of chronic inflammation. Cytokines modulate hepcidin expression and iron sequestration by the reticuloendothelial system but their direct effects on small bowel iron transport are not well characterized. The aim of the present study was to examine the local effects of TNFalpha (tumour necrosis factor alpha) on small bowel iron transport and on iron transporter expression in the absence of hepcidin. The effects of TNFalpha on iron transport were determined using radiolabelled iron in an established Caco-2 cell model. The effect of TNFalpha on the expression and localization of the enterocyte iron transporters DMT-1 (divalent metal transporter 1), IREG-1 (iron-regulated transporter 1) and ferritin was determined utilizing Caco-2 cells and in a human ex vivo small bowel culture system. TNFalpha mediated an early induction in both iron import and iron export, which were associated with increased DMT-1 and IREG-1 mRNA and protein expression (P<0.05). However, by 24 h, both iron import and iron export were significantly inhibited, coinciding with an induction of ferritin heavy chain (P<0.05) and a decrease in DMT-1 and IREG-1 to baseline levels. In addition, there was a relocalization of IREG-1 away from the basolateral cell border and increased iron deposition in villous enterocytes. In conclusion, TNFalpha has a direct effect on small bowel iron transporter expression and function, leading to an inhibition of iron transport.

Serum pro-hepcidin: measuring active hepcidin or a non- functional precursor?

We read with great interest the paper “Pro-hepcidin: expression and cell specific localisation in the liver and its regulation in hereditary haemochromatosis, chronic renal insufficiency, and renal anaemia” ( Gut 2004; 53 :735–43) . We have two observations. Firstly it was shown that pro-hepcidin and hepcidin were colocalised within the liver and in Hep-G cells. However, it was not possible, using serum ELISA, to identify the C terminus of …

Hypertension and fatty liver: guilty by association?

Essential hypertension is associated with the metabolic syndrome, insulin resistance and the development of fatty liver. Fatty liver disease is a spectrum of liver diseases ranging from simple hepatic steatosis through steato-hepatitis to cirrhosis and hepatoma. The purpose of this review is to discuss the evidence for an association between essential hypertension and non-alcoholic fatty liver disease, and to consider the diagnosis and management of non-alcoholic fatty liver disease. We conclude that it is important to consider the diagnosis of fatty liver disease in hypertensive patients, to measure the liver function tests at diagnosis and not to ignore minor elevations of serum aminotransferases. Hypertensive patients with raised liver enzymes should be referred for further assessment, particularly if risk factors for progressive liver disease, such as obesity and diabetes, are present.

The feasibility and clinical efficacy of intravenous iron administration for preoperative anaemia in patients with colorectal cancer

The study aimed to analyse the feasibility and efficacy of administration of a single intravenous iron infusion (IVI) in the preoperative optimization of colorectal cancer patients with anaemia.

Cerebral salt wasting syndrome in meningoencephalitis: a case report

Acute hyponatraemia is a common finding in patients with intracranial pathology. The diagnosis of the syndrome of inappropriate antidiuretic hormone (SIADH) is often made, but it is important to distinguish this from cerebral salt wasting syndrome, which responds to very different management. Cerebral salt wasting is well documented in neurosurgical patients and in patients with space occupying pathology. We present a case of a 26 year old man who developed cerebral salt wasting syndrome during an episode of meningoencephalitis. A 26 year old man was admitted through the A&E department to a local district general hospital with four days of episodic confusion. There was no significant past medical or family history. Recreational drug use was denied and a urine screen was negative. A diagnosis of toxic encephalopathy was made. On day 2 he became pyrexial and agitated, and was sedated with haloperidol. Otherwise his examination was unremarkable, and his Glasgow coma scale (GCS) was 15, with no focal neurology. Routine blood tests, chest x ray, and computed tomography (CT) of the head were normal. CSF examination …