Cerebellar degeneration and hearing loss in a patient with idiopathic myenteric ganglionitis

A 35-year-old male with an 11-year history of intestinal pseudo-obstruction associated with an idiopathic inflammatory insult of the myenteric plexus and the presence of circulating anti-Hu antibodies developed a neurological syndrome characterized by bilateral hearing loss, deteriorating balance, an unsteady gait and difficulty in estimating distances. A similar neurological syndrome has previously been described in older patients among the paraneoplasic syndromes associated with small-cell lung carcinoma and the presence of circulating anti-Hu antibodies, but never in the rare cancer-free patients with anti-Hu-associated chronic idiopathic intestinal pseudo-obstruction. The patient underwent a steroid treatment. No further episodes of functional intestinal obstruction were observed and, after an initial improvement, the neurological symptoms stabilized, leaving a permanent reduction in hearing function and an unsteady gait. The case shows that an idiopathic inflammatory insult of the myenteric plexus may precede (and perhaps lead to) central nervous system impairment in patients with anti-Hu-associated chronic idiopathic intestinal pseudo-obstruction.

"Pseudotumoral" hepatic areas in acute alcoholic hepatitis: a computed tomography and histological study

Computed tomography (CT) findings in acute alcoholic hepatitis (AAH) have not been investigated and a "pseudotumoral aspect" of the liver parenchyma has rarely been reported as an exceedingly unusual finding. We observed 11 patients with AAH over a 1-yr period, five of whom underwent CT for concomitant clinical reasons. Arterial enhancement indicated areas of hypervascularized tissue in all cases, and the histological findings were fully consistent with AAH without any sign of malignancy. The present findings suggest that the above pattern is not uncommon in AAH and should be carefully considered in order to avoid diagnostic errors.

Plasma chromogranin A in patients with autoimmune chronic atrophic gastritis, enterochromaffin-like cell lesions and gastric carcinoids

OBJECTIVE

In atrophic body gastritis (ABG) chronic hypergastrinaemia stimulates enterochromaffin-like (ECL) cell proliferation with development of cell hyperplasia, dysplasia and possibly type-1 gastric carcinoids. As circulating chromogranin A (CgA) levels are a marker of neuroendocrine tumours, we evaluated the clinical usefulness of CgA assay in ABG patients to detect those with carcinoids.

DESIGN AND METHODS

Plasma CgA levels were measured using a commercial ELISA in 45 healthy volunteers, nine patients with type-1 gastric carcinoids and 43 consecutive ABG patients (21 without and 22 with ECL cell hyperplasia/dysplasia).

RESULTS

CgA levels were significantly higher in ABG patients with and without gastric carcinoids than in healthy subjects (P < 0.001). The highest values occurred in patients with carcinoids (median (interquartile range): 58.1 (44.5-65.3) U/l) and with ECL cell hyperplasia/dysplasia (35.5 (31.8-48.65) U/l) but there were no significant differences in CgA among the various subgroups of ABG patients classified according to ECL cell status. Nevertheless, in ABG patients without carcinoids CgA values correlated with the presence and severity of ECL cell lesions (r(s) = 0.428, P < 0.01). The sensitivity and specificity of the CgA assay in identifying patients with carcinoids were 100 and 23% respectively.

CONCLUSIONS

CgA plasma levels reflect the histological degree of ECL cell lesions in patients with ABG but the assay specificity is too low to detect among these patients those with gastric carcinoids.

[Therapy strategies in the prevention of chronic allograft nephropathy]

Chronic allograft nephropathy (CAN) is an anatomical and clinical alteration, characterized by proteinuria, hypertension and a progressive decline in kidney function, which begins at variable times (months, years) and can lead to the loss of the transplanted organ. CAN pathogenesis, which remains to be fully clarified, involves both immunological (early acute rejection, hyperimmunization, HLA-mismatches between donor and recipient, suboptimal immunosuppression, etc) and non-immunological factors (ischemia/reperfusion injury, reduced nephron mass, age differences between donor and recipient, dialysis time, hypertension, dislipidemia, proteinuria, etc). The possible prevention strategies for CAN consist of procedures aimed at the reduction of some potential risk factors: optimization of the conditions for organ explantation, diminution of ischemia/reperfusion injury, aggressive pharmacological treatment of acute rejection episodes, routine utilization of anti-hypertensive and hypolipidemic agents, and appropriate and rational immunosuppressive regimen. Moreover, some categories of immunosuppressive drugs, such as calcineurin inhibitors, can have a nephrotoxic effect, often regardless of therapeutic dosage. The introduction in clinical practice of novel immunosuppressive drugs with no nephrotoxicity, like mycophenolate mofetil and rapamycin, makes therapeutical strategies able to reduce the incidence of CAN feasible.

Erythrocyte ferritin concentration: analytical performance of the immunoenzymatic IMx-Ferritin (Abbott) assay

Together with serum ferritin, erythrocyte ferritincan be a valuable diagnostic tool for evaluating the degree of impaired iron metabolism in different diseases. We collected peripheral blood samples from 64 subjects (22 healthy volunteers, 20 patients with hereditary hemochromatosis, and 22 patients on regular hemodialysis with secondary anemia) to evaluate whether an immunoenzymatic method generally used for serum ferritin can also be used to determine erythrocyte ferritin levels under various conditions of body iron status. Serum and erythrocyte ferritin levels were assayed in parallel using a microparticle enzyme immunoassay (MEIA) IMx-Ferritin kit and an IMx analyzer. The inter-assay imprecision of the serum and erythrocyte ferritin assays was 4.9% and 5.05%, the intra-assay imprecision was 2.2% and 2.3%, and the mean recovery was 102% (range 96–105%) and 101% (range 99–105%), respectively. Both serum and erythrocyte ferritin assays showed a detection limit of 1μg/L and good linearity (R

Transmitter content, origins and connections of axons in the spinal cord that possess the serotonin (5-hydroxytryptamine) 3 receptor

Recent evidence suggests that serotonin has pronociceptive actions in the spinal cord when it acts through 5-hydroxytryptamine (5-HT)(3) receptors. Cells and axon terminals which are concentrated in the superficial dorsal horn possess this receptor. We performed a series of immunocytochemical studies with an antibody raised against the 5-HT(3A) subunit in order to address the following questions: 1) Are axons that possess 5-HT(3) receptors excitatory? 2) Are 5-HT(3) receptors present on terminals of myelinated primary afferents? 3) What is the chemical nature of dorsal horn cells that possess 5-HT(3) receptors? 4) Do axons that possess 5-HT(3) receptors target lamina I projection cells? Approximately 45% of 5-HT(3A) immunoreactive boutons were immunoreactive for the vesicular glutamate transporter 2 and almost 80% formed synapse-like associations with GluR2 subunits of the AMPA receptor therefore it is principally glutamatergic axons that possess the receptor. Immunoreactivity was not present on myelinated primary afferent axons labeled with the B-subunit of cholera toxin or those containing the vesicular glutamate transporter 1. Calbindin (which is associated with excitatory interneurons) was found in 44% of 5-HT(3A) immunoreactive cells but other markers for inhibitory and excitatory cells were not present. Lamina I projection cells that possessed the neurokinin-1 receptor were associated with 5-HT(3A) axons but the density of contacts on individual neurons varied considerably. The results suggest that 5-HT(3) receptors are present principally on terminals of excitatory axons, and at least some of these originate from dorsal horn interneurons. The relationship between lamina I projection cells and axons possessing the 5-HT(3) receptor indicates that this receptor has an important role in regulation of ascending nociceptive information.

Quality-related variables at hepatological websites

BACKGROUND

The amount of hepatology-related information available on the Internet has substantially increased, but little is known about the characteristics and quality of the websites.

AIM

The aim of this study was to describe analytically and evaluate critically the information concerning three diseases of hepatological interest: chronic hepatitis, hemochromatosis and Caroli's disease.

METHODS

In accordance with a validated method, the three search terms were entered into four English language search engines and the first five links of each were considered (a total of 60 sites). The characteristics of the websites were described and their quality was evaluated by three independent reviewers who assigned scores of 1-5 for accuracy, reliability and depth. The relationships between the site characteristics and quality scores were analysed by means of multiple logistic regression.

RESULTS

The overall rating score was sufficient (>3) in 51% (95% confidence interval: 38-65%) of cases. The majority of the sites (73%) were aimed at patients rather than at physicians. Commercial sponsorship was significantly more frequent among the chronic hepatitis sites (45%) than among the hemochromatosis (15%) or Caroli's disease sites (0%) (P = 0.002); 61% of the commercial sites did not include a financial disclosure. The only variable that independently related to poor quality was the presence of commercial sponsorship (odds ratio 18.1; 95% confidence interval: 1.7-192.5).

CONCLUSIONS

Hepatological websites are characterised by poor quality and are mainly aimed at patients. Quality is negatively affected by commercial interests, which are often undeclared. Guidelines for the certification and surveillance of websites relating to liver diseases are highly advisable.

Epstein-Barr virus-associated lymphoma in Crohn's disease

Although no increased risk of developing lymphoproliferative disorders has been observed in population-based studies of patients with Crohn's disease, the possibility has been suggested in the subset of patients previously treated with thiopurine metabolites and suffering from concomitant Epstein-Barr virus infection. A few cases of lymphomas have occurred in patients with Crohn's disease treated with infliximab, only one of whom showed the presence of the Epstein-Barr virus genome. We here describe the case of a patient with steroid-dependent ileal Crohn's disease treated with azathioprine and a single infusion of infliximab, who developed a diffuse large B cell ileal lymphoma. Epstein-Barr virus genome was detected in the neoplastic cells by means of polymerase chain reaction. Epstein-Barr virus may be detected in the neoplastic tissues of lymphomas of patients with Crohn's disease treated with immunosuppressants and infliximab. The identification of such cases may help to define the frequency of this association and how to manage the lymphoproliferative disorder.

Adaptive changes of duodenal iron transport proteins in celiac disease

Iron deficiency is a manifestation of celiac disease (CD) usually attributed to a decreased absorptive surface, although no data on the regulation of iron transport under these conditions are currently available. Our aim was to evaluate divalent metal transporter 1 (DMT1), duodenal cytochrome b (Dcytb), ferroportin 1 (FP1), hephaestin, and transferrin receptor 1 (TfR1) expression, as well as iron regulatory protein (IRP) activity in duodenal biopsies from control, anemic, and CD patients. We studied 10 subjects with dyspepsia, 6 with iron-deficiency anemia, and 25 with CD. mRNA levels were determined by real-time PCR, protein expression by Western blotting or immunohistochemistry, and IRP activity by gel shift assay. Our results showed that DMT1, FP1, hephaestin, and TfR1 mRNA levels were significantly increased in CD patients with reduced body iron stores compared with controls, similar to what was observed in anemic patients. Protein expression paralleled the mRNAs changes. DMT1 protein expression was localized in differentiated enterocytes at the villi tips in controls, whereas with iron deficiency it was observed throughout the villi. FP1 expression was localized on the basolateral membrane of enterocytes and increased with low iron stores. TfR1 was localized in the crypts in controls but also in the villi with iron deficiency. These changes were paralleled by IRP activity, which increased in all iron-deficient subjects. We conclude that duodenal DMT1, FP1, hephaestin, and TfR1 expression and IRP activity, thus the iron absorption capacity, are upregulated in CD patients as a consequence of iron deficiency, whereas the increased enterocyte proliferation observed in CD has no effect on iron uptake regulation.

Accuracy of ultrasonography in predicting celiac disease

BACKGROUND

Various ultrasonographic (US) signs have been reported in overt celiac disease (CD). The aim of this study was to investigate the diagnostic accuracy of 6 US parameters in predicting CD.

METHODS

One hundred sixty-two consecutive patients with chronic diarrhea (n=105), iron deficiency anemia (n=25), or dyspepsia (n=32) underwent anti-endomysial IgA antibody determination and duodenal biopsy. Moreover, US evaluation of 6 parameters (ie, fasting gallbladder volume, transverse diameter of small bowel loops, thickness of the small bowel wall, pattern of peristalsis, presence of free abdominal fluid, and diameter of the mesenteric lymph nodes) was done by 2 operators blind to the serological and histological findings. The pretest probability of CD was estimated to be between 5% and 10%. The percentage of agreement between US and histologic findings, the sensitivity, specificity, positive and negative likelihood ratios, and the posttest probability for positive and negative results were calculated.

RESULTS

Celiac disease was diagnosed in 12 patients (7.4%). An increased gallbladder volume, the presence of free fluid in the abdominal cavity, and enlarged mesenteric lymph nodes showed a specificity of 96%, 96%, and 97%, respectively (95% confidence intervals [CIs], 92%-99%, 93%-99%, and 95%-99%), whereas the presence of dilated small bowel loops with increased fluid content and increased peristalsis had a sensitivity of 92% and 83%, respectively (95% CIs, 76%-100% and 62%-100%). Eleven (92%) of the 12 patients with celiac disease and 35 (23%) of the 150 patients who did not have the disease had at least 1 US sign (P=.001); all of the US signs were concomitantly present in 4 patients with CD (33%) and 1 patient without CD (0.6%) (P=.001).

CONCLUSION

Ultrasonographic evaluation can accurately predict CD but its place in the diagnostic algorithm depends upon the probability of the disease in the considered population.

Gallstone disease and related risk factors in a large cohort of diabetic patients

BACKGROUND AND AIM

The aim of this study of a large cohort of consecutive patients with diabetes mellitus was to investigate the still controversial questions concerning the prevalence and possible risk factors of gallstone disease in diabetics.

PATIENTS AND METHODS

We enrolled 1337 consecutive patients (710 males aged 63 +/- 11 years and 627 females aged 65 +/- 11 years), of whom 1235 (92%) had type 2 and 102 (8%) had type 1 diabetes mellitus. The data were statistically analysed using multiple logistic regression analysis.

RESULTS

The prevalence of gallstone disease was significantly higher in diabetics than in the general population with comparable characteristics (MICOL study) (332/1337 (24.8%) versus 4083/29684 (13.8%); z = 11.208, P = 0.0001) and this difference maintained its statistical significance even when only the North Italian centers involved in this nation-wide survey were considered (332/1337 (24.8%) versus 2469/18091 (13.6%); z = 11.225, P = 0.0001). A total of 332 diabetics (25%) had gallstone disease: 261 had stone(s) and 71 had previously undergone cholecystectomy for gallstone disease after a diagnosis of diabetes mellitus. The prevalence of gallstone disease was higher in the females (29% versus 22%, P = 0.003), and increased with age (13, 20 and 30% in patients aged < or = 40, 41-65 and > 65 years, respectively; P = 0.001), body mass index (24% in patients with a body mass index of < or = 30 and 30% in those with a body mass index of > 30 kg/m2; P = 0.001) and a positive family history of gallstone disease (31% versus 23%; P = 0.001). Gallstone disease was not significantly related to the type of diabetes, plasma total and HDL cholesterol and triglyceride levels, alcohol intake, smoking habits, physical activity, weight reduction in the last year, the use of oral contraceptives, parity or menopause. At multivariate analysis, increasing age, a higher body mass index and a positive family history maintained their statistical significance.

CONCLUSIONS

In patients with type 1 or type 2 diabetes mellitus, the prevalence of gallstone disease was significantly related to age, body mass index and a family history of gallstone disease.

Ghrelin administration affects circulating pituitary and gastro-entero-pancreatic hormones in acromegaly

OBJECTIVE

Ghrelin, a gut-brain peptide involved in the control of energy homeostasis, affects antero-pituitary and gastro-entero-pancreatic (GEP) hormone secretion in healthy subjects. We aimed to verify whether such hormonal responses are retained in acromegaly, a disease characterized by high GH, subnormal ghrelin and abnormal GEP hormone levels.

DESIGN AND METHODS

The effect of ghrelin (3.3 microg/kg given after overnight fasting as an i.v. bolus) on GH, prolactin (PRL), adrenocorticotropin (ACTH), cortisol, insulin, glucose, total somatostatin (SS) and pancreatic polypeptide (PP) circulating levels were evaluated in seven non-diabetic patients with newly diagnosed acromegaly and in nine healthy controls.

RESULTS

Ghrelin elicited a prompt, marked increase of serum GH and PRL levels in all normal (from 1.6+/-0.6 to 52.9+/-7.8 and from 9.7+/-0.8 to 24.2+/-4.8 microg/l (means+/-S.E.M.), respectively) and acromegalic subjects (from 11.2+/-4.9 to 91.6+/-21.0 and from 42.9+/-26.1 to 113.8+/-79.0 microg/l, respectively). Both plasma ACTH and serum cortisol levels rose significantly in the controls, whereas the cortisol response was blunted in the acromegalic patients. Glucose levels rose earlier and insulin levels fell later in all subjects, with a significantly greater net insulin decrease in acromegalic than in healthy subjects (-80+/-21 vs -17+/-4 pmol/l, P<0.01). A prompt PP rise and a biphasic SS response occurred in all controls, whereas in the acromegalic group the PP response (from 26.1+/-5.0 to 92.2+/-39.0 pmol/l) and the SS response (from 11.9+/-3.0 to 19.7+/-4.0 ng/l) were quite variable.

CONCLUSIONS

Ghrelin affects both pituitary and GEP hormones in acromegalic patients as in normal subjects. These findings suggest that ghrelin actions on the energy balance are mediated by complex interactive endocrine loops that involve also the gut and pancreas.

Circulating ghrelin levels in celiac patients

OBJECTIVE

Ghrelin, the gut-brain peptide, recently identified as the natural endogenous ligand for growth hormone secretagogue receptors, exerts various endocrine and nonendocrine effects, including the control of energy homeostasis and food intake, but its possible relevance in malabsorption syndromes is unknown. Therefore, the aim of this study was to evaluate circulating ghrelin levels in adults with untreated and treated celiac disease (CD) and, for comparison, in healthy subjects.

METHODS

Fasting serum ghrelin levels were measured in 30 consecutive patients with newly diagnosed CD, 13 celiac patients successfully treated with a gluten-free diet (GFD), and 30 healthy controls.

RESULTS

Ghrelin levels were abnormally high in patients with active CD compared with controls (297 +/- 17.6 vs 218 +/- 15.2 pmol/L, p<0.01) and correlated positively with intestinal mucosal lesion severity (rs=0.444, p<0.02). In the successfully GFD-treated patients, ghrelin values were normal compared with controls (233 +/- 22.0 vs 218 +/- 15.2 pmol/L, ns) and, moreover, correlated negatively with body mass index (r=-0.632, p=0.02), unlike in the untreated patient group (r=-0.263, ns).

CONCLUSION

High ghrelin levels characterized our series of adult patients with newly diagnosed CD and correlated significantly with the degree of severity of intestinal mucosal lesions. This is the first evidence of a relationship between ghrelin and inflammatory processes, but the mechanisms involved are still unclear. Furthermore, our findings suggest that an interplay of hormonal, metabolic, and nutritional factors could influence ghrelin secretion under pathophysiological circumstances.

Oxidative stress-mediated down-regulation of rat hydroxyacid oxidase 1, a liver-specific peroxisomal enzyme

Hydroxyacid oxidase 1 (Hao1) is a liver-specific peroxisomal enzyme that oxidizes glycolate to glyoxylate with concomitant production of H2O2. In Hao1 messenger RNA (mRNA), an iron-responsive element (IRE) homologous to the sequence recognized by iron regulatory proteins (IRP), key regulators of iron homeostasis, is present, but the involvement of iron in Hao1 regulation remains unclear. In this study, we found a reduction of Hao1 mRNA content in livers of rats with chronic dietary iron overload, which showed decreased IRP activity and higher ferritin expression as expected, but also induction of heme oxygenase (HO-1), a marker of oxidative damage, and lipid peroxidation. Hao1 mRNA levels were not altered significantly in livers of rats administered doses of iron sufficient to induce ferritin expression and to repress IRP activity, but not to activate HO-1 and to promote lipid peroxidation, as well as in the liver of iron-deficient rats. These observations were not consistent with a post-transcriptional down-regulation of Hao1 by iron through the IRE/IRP pathway and suggested an effect of reactive oxygen species (ROS). Indeed, a marked decrease of Hao1 mRNA was observed in the liver of rats subjected to oxidative stress induced by either glutathione depletion or postischemic reperfusion. Nuclear run-on analysis showed an effect of ROS at the transcriptional level. In conclusion, down-regulation of Hao1 expression during oxidative stress may provide a mechanism to prevent excessive H2O2 formation in liver peroxisomes and may represent the prototype of a poorly recognized but potentially relevant response to oxidative injury involving down-regulation of ROS-producing enzymes.

Gallbladder motility in obesity, diabetes mellitus and coeliac disease

We reviewed data on gallbladder motility in obesity, diabetes and coeliac disease. In obesity, a condition characterised by increased risk of gallstone(s), decreased gallbladder motility has heterogeneously been reported as a consequence of the different type of meals used to induce gallbladder contraction, characteristics of the population studied, technique used, and proportion of patients with hyperinsulinaemia. Moreover, recent studies have evaluated the effect of dietary restriction on gallbladder motility in obese patients. A two- to three-fold increase in the risk of cholesterol gallstone(s) has been reported in diabetic patients, mainly in relation to obesity and hypertriglyceridaemia. Furthermore, decreased gallbladder motility has been described and attributed to other factors, including underlying autonomic neuropathy, reduced gallbladder sensitivity to cholecystokinin and/or reduced number of cholecystokinin receptors on the gallbladder wall. Impaired gallbladder motility has been reported also in patients with coeliac disease in relation to reduced secretion of enteric hormones and/or decreased gallbladder sensitivity to them. In particular, untreated coeliacs, when compared to controls, showed low postprandial cholecystokinin and increased fasting somatostatin levels. Interestingly, the correlation between fasting somatostatin levels and gallbladder size has clearly been confirmed in patients affected by somatostatinoma or treated with somatostatin or its analogues. Gallbladder motility can be affected by various clinical conditions, such as obesity, diabetes mellitus and coeliac disease.

Severe liver fibrosis or cirrhosis: accuracy of US for detection--analysis of 300 cases

PURPOSE

To determine the accuracy of various ultrasonographic (US) signs for assessment of the degree of liver fibrosis, with histologic results as reference standard.

MATERIALS AND METHODS

Three hundred consecutive asymptomatic patients with at least 6 months of increased levels of aspartate aminotransferase and/or alanine aminotransferase underwent liver US and biopsy. The estimated pretest probability of severe fibrosis or cirrhosis was 35%. Three US parameters were investigated: liver surface nodularity, caudate lobe hypertrophy, and pattern of hepatic venous blood flow. US results were compared with histologic results obtained after liver biopsy, which constituted the reference standard for diagnosis of severe fibrosis or cirrhosis. The degree of fibrosis was graded according to METAVIR criteria, with stages 3 and 4 considered together. Data were analyzed with kappa and chi2 statistics. Sensitivity, specificity, positive and negative likelihood ratios, and posttest probability were calculated for each US sign.

RESULTS

In 107 (36%) patients with severe fibrosis (n = 34) or cirrhosis (n = 73), liver surface nodularity had the highest diagnostic accuracy, with specificity of 95% and positive and negative likelihood ratios 11.6 and 0.51, respectively. When liver surface nodularity was considered alone, posttest probability of severe fibrosis or cirrhosis increased from 35% to 86%. When caudate lobe hypertrophy and hepatic venous blood flow were also taken into account, posttest probability increased by only 2% (ie, to 88%).

CONCLUSION

US determination of liver surface nodularity is an accurate method for identifying the subset of asymptomatic patients with severe liver fibrosis or cirrhosis, which indicates a worse prognosis.

A puzzling jaundice

In an adult beta-thalassaemic patient admitted on account of the sudden onset of nausea, vomiting and biliary pain, the concomitant jaundice was considered "obstructive" on the basis of ultrasonographic evidence of cholecysto-choledocal stones. However, when the patient was re-evaluated it was found that concomitant Gilbert's disease, hepatitis C virus related cirrhosis and dilated cardiomyopathy had a detrimental effect on clinical and laboratory findings.

Plasma chromogranin A in patients with sporadic gastro-entero-pancreatic neuroendocrine tumors or multiple endocrine neoplasia type 1

OBJECTIVE

As circulating chromogranin A (CgA) has been claimed to be the best general neuroendocrine marker so far available, we evaluated the usefulness of CgA determination in the clinical assessment of patients with sporadic gastro-entero-pancreatic neuroendocrine tumors (GEP NETs) or multiple endocrine neoplasia type 1 (MEN 1).

DESIGN AND METHODS

Plasma CgA levels were measured using a commercial enzyme-linked immunosorbent assay in 61 patients with sporadic GEP NET and in 25 with MEN 1 including 16 with GEP NET. Controls were 50 healthy volunteers, 46 patients with pituitary adenoma and 35 patients with primary hyperparathyroidism.

RESULTS

The cutoff value for CgA established in our healthy subjects (as mean+2 s.d.) was 20 U/l. CgA levels were above the normal range in 71/77 patients with sporadic or MEN 1-related GEP NETs (92%), in four out of nine MEN 1 patients without GEP NETs (44%), and only in 22/81 control patients with pituitary or parathyroid disease (27%). Furthermore, CgA levels of over 100 U/l occurred in 36/77 patients with GEP NETs (47%) and only in one patient with a non-functioning pituitary adenoma. In the patients with GEP NETs, both tumor burden and secretory activity affected CgA levels, and successful surgical resection was associated with markedly decreased CgA values.

CONCLUSIONS

Plasma CgA was confirmed to be a reliable marker for GEP NETs. Moreover, in MEN 1 patients the finding of very high CgA levels strongly suggests the presence of a GEP NET, as both primary hyperparathyroidism and pituitary adenomas rarely cause marked CgA increases.

Transferrin receptor 1 (TfR1) and putative stimulator of Fe transport (SFT) expression in iron deficiency and overload: an overview

Transferrin Receptor 1 (TfR1) and putative Stimulator of Fe Transport (SFT) represent two different proteins involved in iron metabolism in mammalian cells. The expression of TfR1 in the duodenum of subjects with normal body iron stores has been mainly localized in the basolateral portion of the cytoplasm of crypt cells, supporting the idea that this molecule may be involved in the sensing of body iron stores. In iron deficiency anemia TfR1 expression demonstrated an inverse relationship with body iron stores as assessed by immunohistochemistry with anti-TfR1 antibodies. In iron overload, TfR1 expression in the duodenum differed according to the presence or absence of the C282Y mutation in the HFE gene, being increased in HFE-related hemochromatosis and similar to controls in non-HFE-related iron overload. SFT is characterized by its ability to increase iron transport both through the transferrin dependent and independent uptake, and could thus affect iron absorption in the intestine. Immunohistochemistry using anti-SFT antibodies which recognize a putative stimulator of Fe transport of approximately 80 KDa revealed a localization of this protein in the apical part of the cytoplasm of enterocytes localized at the tip of the villi. The expression of the protein recognized by these antibodies was increased in iron deficiency, as well as in patients carrying the C282Y HFE mutation. Thus, the increased expression of both proteins only in patients with HFE-related hemochromatosis suggests that other factors should be involved in determining non-HFE-related iron overload.

Tissue transglutaminase antibodies in patients with end-stage heart failure

OBJECTIVE

For celiac disease (CD), screening a trend has recently emerged to measure tissue transglutaminase antibodies (tTGA) by immunoassays instead of the more laborious endomysial antibodies (EmA), as they recognize the same target, tissue transglutaminase (tTG). However, a high rate of false-positive results has been reported in some patient series with diseases known to be associated with CD. Moreover, tTG is a ubiquitous, multifunctional enzyme, overexpressed in experimental models of heart failure. Therefore, we assessed the specificity of tTGA assays in a large series of EmA-negative patients with end-stage heart failure.

METHODS

We studied 288 patients with end-stage heart failure and 60 blood donors. No subject had clinical evidence of CD or IgA deficiency, and all were EmA negative. Serum IgA and IgG tTGA were measured by means of commercial kits using as substrate, either guinea pig or recombinant human tTG. Blocking studies and Western blots were also performed using recombinant human tTG.

RESULTS

All blood donor sera were IgA tTGA negative. IgA tTGA positivity was observed in 47.6% and 49.1% of patients with heart failure using, respectively, guinea pig tTG and recombinant human tTG as substrates. Preincubation of positive sera with recombinant human tTG resulted in 81% blocking of IgA tTGA in immunoassay. Western blot analysis confirmed the presence of antibodies against recombinant human tTG. IgA tTGA-positive sera were also IgG tTGA positive.

CONCLUSIONS

IgA and IgG tTGA occur in a large number of EmA-negative patients with end-stage heart failure, and their presence is unlikely to be caused by concomitant CD.