Efficacy of Retreatment After Failed Direct-acting Antiviral Therapy in Patients With HCV Genotype 1-3 Infections

Hepatitis C virus infection is causing chronic liver disease, cirrhosis, and hepatocellular carcinoma. By combining direct-acting antivirals (DAAs), high sustained virologic response rates (SVRs) can be achieved. Resistance-associated substitutions (RASs) are commonly observed after DAA failure, and especially nonstructural protein 5A (NS5A) RASs may impact retreatment options.^1-3 Data on retreatment of DAA failure patients using first-generation DAAs are limited.^4-7 Recently, a second-generation protease- and NS5A-inhibitor plus sofosbuvir (voxilaprevir/velpatasvir/sofosbuvir [VOX/VEL/SOF]) was approved for retreatment after DAA failure.⁸ However, this and other second-generation regimens are not available in many resource-limited countries or are not reimbursed by regular insurance, and recommendations regarding the selection of retreatment regimens using first-generation DAAs are very important. This study aimed to analyze patients who were re-treated with first-generation DAAs after failure of a DAA combination therapy.

Effect of mycophenolic acid on inosine monophosphate dehydrogenase (IMPDH) activity in liver transplant patients

BACKGROUND

Due to the development of immunosuppressants, the focus in transplanted patients has shifted from short-term to long-term survival as well as a better adjustment of these drugs in order to prevent over- and under-immunosuppression. Mycophenolic acid (MPA) is a noncompetitive inhibitor of inosine monophosphate dehydrogenase (IMPDH) and approved for prophylaxis of acute rejection after kidney, heart, and liver transplantation, where it has become a part of the standard therapy. Targeting inosine monophosphate IMPDH activity as a surrogate pharmacodynamic marker of MPA-induced immunosuppression may allow a more accurate assessment of efficacy and aid in limiting toxicity in liver transplanted patients.

AIM

Assess IMPDH-inhibition in liver transplant recipients and its impact on biliary/infectious complications, acute cellular rejection (ACR) and liver dependent survival.

METHODS

This observational cohort study comprises 117 liver transplanted patients that were treated with mycophenolate mofetil (MMF) for at least 3 months. Blood samples (BS) were collected and MPA serum level and IMPDH activity were measured before (t(0)), 30minutes (t(30)) and 2h after (t(120)) MMF morning dose administration. Regarding MPA, we assessed the area under the curve (AUC). Patients were prospectively followed up for one year and assessed for infectious and biliary complications, episodes of ACR and liver dependent survival.

RESULTS

The MPA levels showed a broad interindividual variability at t(0) (2.0±1.8ng/ml), t(30) (12.7±9.0ng/ml) and t(120) (7.5±4.3ng/ml). Corresponding IMPDH activity was at t(o) (23.2±9.5 nmol/h/mg), at t(30) (16.3±8.8 nmol/h/mg) and t(120) (18.2±8.7 nmol/h/mg). With regard to MPA level we found no correlation with infectious or biliary complications within the follow-up period. Patients with baseline IMPDH(a) below the median had significant more viral infections (6 (10.2%) vs. 17 (29.3%); P=0.009) with especially more cytomegalovirus (CMV) infections (1 (3.4%) vs. 6 (21.4%); P=0.03)). Furthermore, patients with baseline IMPDH(a) above the median developed more often non-anastomotic biliary strictures (8 (13.6%) vs. 1 (1.7%), P=0.03). We found the group reaching the combined clinical endpoint of death and re-transplantation showing significantly lower MPA baseline values (t(0) 0.9±0.7 vs. 2.1±1.8μg/ml Mann-Whitney-U: P=0.02). We calculated a simplified MPA(AUC) with the MPA level at baseline, 30 and 120minutes after MPA administration. Whereas we found no differences with regard to baseline characteristics at entry into the study patients with MPA (AUC) below the median experienced significantly more often the combined clinical endpoint (12.1% (7/58) vs. 0.0% (0/57); P=0.002) and had a reduced actuarial re-transplantation-free survival (1.0 year vs. 0.58 years; Log-rank: P=0.007) during the prospective one-year follow-up period. In univariate and multivariate analysis including gender, age, BMI, ACR, MPA (AUC) and IMPDH(a) only BMI, MPA (AUC) and IMPDH(a) were independently associated with reduced actuarial re-transplantation-free survival.

CONCLUSION

MPA-levels and IMPDH-activity in liver transplanted patients allows individual risk assessment. Patients with higher IMPDH inhibition acquire more often viral infections. Insufficient IMPDH inhibition is associated with development of non-anastomotic bile duct strictures and reduced re-transplantation-free survival.

Cardiac volume overload and pulmonary hypertension in long-term follow-up of patients with a transjugular intrahepatic portosystemic shunt

BACKGROUND

Transjugular intrahepatic portosystemic shunt (TIPSS) cause haemodynamic changes in patients with cirrhosis, yet little is known about long-term cardiopulmonary outcomes.

AIM

To evaluate the long-term cardiopulmonary outcome after TIPSS.

METHODS

We evaluated cardiopulmonary parameters including echocardiography during long-term follow-up after TIPSS. Results at 1-5 years after TIPSS were compared to those of cirrhotic controls. Pulmonary hypertension (PH) diagnoses rates were included. Endothelin 1, thromboxane B2 and serotonin were measured.

RESULTS

We found significant differences 1-5 years after TIPSS compared to pre-implantation values: median left atrial diameter (LAD) increased from 37 mm [interquartile range (IQR): 33-43] to 40 mm (IQR: 37-47, P = 0.001), left ventricular end-diastolic diameter (LV-EDD) increased from 45 mm (range: 41-49) to 48 mm (IQR: 45-52, P < 0.001), pulmonary artery systolic pressure (PASP) increased from 25 mmHg (IQR: 22-33) to 30 mmHg (IQR: 25-36, P = 0.038). Comparing results 1-5 years post-implantation to the comparison cohort revealed significantly higher (P < 0.05) LAD, LV-EDD and PASP values in TIPSS patients. PH prevalence was higher in the shunt group (4.43%) compared to controls (0.91%, P = 0.150). Thromboxane B2 levels correlated with PASP in the TIPSS cohort (P = 0.033). There was no transhepatic gradient observed for the vasoactive substances analysed.

CONCLUSIONS

TIPSS placement is accompanied by long-term cardiovascular changes, including cardiac volume overload, and is associated with an increased rate of pulmonary hypertension. The need for regular cardiac follow-up after TIPSS requires further evaluation.

Reduction in alkaline phosphatase is associated with longer survival in primary sclerosing cholangitis, independent of dominant stenosis

BACKGROUND

Alkaline phosphatase (ALP) is an important serum marker in primary sclerosing cholangitis (PSC). Patients with obstruction of the large bile ducts due to dominant strictures (DS) are a special, clinically important phenotype.

AIM

To determine the impact of ALP reduction on liver transplantation-free survival in PSC patients with DS.

METHODS

Prospective cohort study in 215 PSC patients. We performed subgroup analysis for patients without DS (no DS, n = 84), DS at first presentation (DS early, n = 72) and development of DS during the course of the study (DS late, n = 59). We evaluated two scores of ALP reduction. ALP reduction 1 was defined as ALP normalisation, 50% reduction compared with baseline values, or reduction below 1.5 times of upper limit of normal (ULN) within 6 months. ALP reduction 2 was defined as ALP reduction below 1.5 times of ULN within 12 months.

RESULTS

Of the patients, 59.5% reached an ALP reduction 1 and 56.7% according to ALP reduction 2. Achievement of each score was associated with longer transplantation-free survival in all three groups (ALP reduction 1: no DS P = 0.001; DS early P < 0.001; DS late P = 0.022; ALP reduction 2: no DS P = 0.014; DS early P = 0.001; DS late P = 0.002). Cox-regression analysis revealed each score as an independent predictor for improved transplantation-free survival (ALP reduction 1 and 2 P < 0.001 each). We further analysed previously published scores of ALP improvement in PSC showing also improved survival in patients with ALP normalisation or a reduction below 1.5 times of ULN (P = 0.003, P = 0.001, respectively), whereas the score determined by 40% reduction did not show significant differences in survival (P = 0.55).

CONCLUSIONS

Reduction in alkaline phosphatase values within the first year is associated with improved transplantation-free survival in patients with primary sclerosing cholangitis independent of the presence of dominant strictures. Alkaline phosphatase might be an adequate surrogate marker for outcome assessment in clinical studies both for patients with and without dominant strictures.

Fut2 genotype is a risk factor for dominant stenosis and biliary candida infections in primary sclerosing cholangitis

BACKGROUND

A recent genome-wide association study identified the FUT2 secretor status and genotype defined by the single-nucleotide polymorphism rs601338 as potential genetic risk factor in primary sclerosing cholangitis (PSC), which significantly influences biliary bacterial composition.

AIM

To determine the impact of the rs601338-FUT2 genotype on frequency of biliary infections, development of dominant stenosis and liver-transplantation-free survival in patients with PSC.

METHODS

Cohort study of 215 patients with PSC treated at our tertiary care centre with respect to their rs601338-FUT2 genotype. Results of endoscopic retrograde cholangiography and bile culture were analysed; 639 biliary samples were obtained, cultured and subjected to microbial analysis. Clinical and laboratory data were analysed using chart reviews.

RESULTS

For the rs601338-FUT2 genotype, 69 patients (32.1%) were found to be wildtype (GG), 97 (45.1%) patients were heterozygous (AG) and 49 patients (22.8%) were homozygous-mutated (AA). In addition to alterations in the bacterial pattern, especially in heterozygous carriers, patients with mutated alleles had a marked increase in the frequency of biliary Candida infections (P = 0.025). Further, patients with mutated alleles showed an increased frequency of episodes of cholangitis (P = 0.0025), development of dominant stenosis (P < 0.002) and a reduced actuarial transplantation-free survival (P = 0.044). Levels of biliary Ca19-9 were significantly elevated in the homozygous-mutated patients.

CONCLUSIONS

The rs601338-FUT2 genotype is strongly associated with episodes of cholangitis, fungobilia and the incidence of dominant stenosis, which are three clinical hallmarks of PSC; FUT2 is thus an important genetic risk factor for host-microbial diversity and disease progression in PSC.

Reduced residual gene expression of nuclear factor of activated T cells-regulated genes correlates with the risk of cytomegalovirus infection after liver transplantation

BACKGROUND

Pharmacokinetic monitoring of calcineurin inhibitors (CNIs) is unsatisfactory because, at comparable blood concentrations, side effects vary considerably. We recently confirmed the applicability of a pharmacodynamic (PD) assay that measures the suppression of CNI target genes, specifically the suppression of nuclear factor of activated T cells (NFAT)-regulated genes in liver transplant (LT) recipients. The aim of this prospective study was to prove the clinical reliability of this assay. Therefore, we quantified the residual gene expression (RGE) of NFAT-regulated genes and evaluated the association between the RGE of NFAT-regulated genes and the incidence of cytomegalovirus (CMV) infection.

PATIENTS AND METHODS

In 20 LT recipients, 10 patients on cyclosporine (CsA) and 10 patients on tacrolimus (Tac) therapy, who presented with CMV infection, the RGEs of interleukin-2, interferon-γ (IFNγ), and granulocyte-monocyte colony-stimulating factor were measured and compared with the RGEs of these cytokines in 40 healthy dose-matched LT controls.

RESULTS

CsA-treated CMV patients demonstrated a lower RGE of all NFAT-regulated genes compared with controls (30 ± 17 vs. 44 ± 20, P = 0.067). For IFNγ, the level of significance was reached (26 ± 17 vs. 43 ± 17, P = 0.0125). Daily CsA dosage, CsA baseline (C0 ) and 2 h (C2 ) concentrations were comparable (CsA dosage 169 mg/day vs. 165 mg/day; CsA C0 94 μg/L vs. 85 μg/L; CsA C2 389 μg/L vs. 381 μg/L). In addition, Tac-treated CMV patients demonstrated a lower RGE of all NFAT-regulated genes compared with controls (68 ± 25 vs. 84 ± 22, P = 0.0769). Analogous to CsA-treated CMV patients, the level of significance was reached for IFNγ (61 ± 24 vs. 88 ± 29, P = 0.0154). Daily Tac dosage and Tac 1.5 h concentrations (C1.5 ) were comparable in both groups (Tac dosage 4 mg/day vs. 4 mg/day; Tac C1.5 8 μg/L vs. 10 μg/L), whereas Tac C0 concentrations were significantly higher in controls (Tac C0 4 μg/L vs. 6 μg/L, P = 0.0276).

CONCLUSION

Measuring the RGE of NFAT-regulated genes is appropriate to assess the risk of infections in LT recipients. Measuring the RGE of IFNγ is particularly suitable to assess the risk of CMV infection. PD monitoring of CNIs in LT recipients is an approach to individualize immunosuppression, which may help to reduce infectious complications.

[Mucosal protection by phosphatidylcholine as new therapeutic concept in ulcerative colitis]

The colonic mucus serves a first barrier towards invasion of commensal bacteria in stool. One essential component of intestinal mucus is phosphatidylcholine (PC) which represents more than 90 % of the phospholipids in mucus indicative for a selective transport of PC into this compartment. It is arranged in lamellar structures as surfactant-like particles which provide a hydrophobic surface on top of the hydrated mucus gel to prevent invasion of bacteria from the intestinal lumen. In ulcerative colitis (UC) the mucus PC content is reduced by 70 % irrespective of the state of inflammation. Thus, it could represent an intrinsic primary pathogenetic condition predisposing to bacterial invasion and precipitation of inflammation. Since PC was shown to be mainly secreted by the ileal mucosa from where it is assumed to move distally to the colon, the PC content along the colonic wall towards the rectum gradually thins out with lowest PC content in the rectum. It explains the start of the clinical manifestation of UC in the rectum and expansion from there to the upper parts of the colon. When the lacking mucus PC in the UC was supplemented by an oral, delayed released PC preparation, it was shown in three clinical trials that the inflammation improved and even resolved. The data indicate the essential role of the mucus phosphatidylcholine content for protection against inflammation in colon. This can be the basis for the development of an innovative therapy for ulcerative colitis using orally available delayed released phosphatidylcholine.

An unusual case of paralytic ileus

A 26-year-old female patient presented with the clinical picture of an acute ileus. Since childhood the patient has been diagnosed as having a MELAS syndrome, a mitochondriopathy. A subtotal colectomy was performed some years ago because of a similar ileus episode. The further diagnostic work-up revealed an expanded small intestine in abdominal radiography. Laboratory analysis showed increased levels of serum lactate with a consecutive respiratory compensated metabolic acidosis. A conservative treatment regime with nasogastric tube, fluid therapy, parental nutrition via peripheral veins and peristalsis inducing drugs was initiated, but did not resolve ileus symptoms. Under the hypothesis that in MELAS syndrome the ileus-related catabolic state aggravates the ileus symptoms in terms of a circulus vitiosus, we started high-caloric parenteral nutrition by using a central venous catheter. A few hours after this intervention, a clear clinical improvement could be observed. Since this initial presentation, the patient was admitted to our hospital several times with the same ileus symptoms. Each of the episodes was successfully and rapidly treated by this high-caloric parenteral nutrition therapy. The reproducible rapid clinical improvement after starting parenteral nutrition supports the hypothesis that an optimal energy supply is the key therapy not only for cerebral but also for gastrointestinal symptoms in patients with MELAS syndrome.

Temporary placement of fully covered self-expandable metal stents in biliary complications after liver transplantation

In the present study we prospectively evaluated the safety and efficacy of temporary fully covered, self-expandable metal stents (fcSEMS) to treat biliary strictures (n = 9), leaks (n = 9), and combined lesions (n = 1) occurring after liver transplantation, when standard endoscopic attempts had failed. Placement of fcSEMS and their removal in scheduled patients were successful and without complications. Resolution of the biliary lesion was confirmed in 15 of 19 patients (79 %). Treatment was not successful in two patients and not evaluable in 2 other patients. Complications occurred in 9 /19 patients (47 %): stent migration in 6, stent occlusion in 1, and de novo stricture after successful treatment of a biliary leak in 2. After a median follow-up of 12 months, one recurrent anastomotic stricture was noted. Temporary placement of fcSEMS in biliary strictures and leaks after liver transplantation provides satisfactory results even in patients who have undergone multiple previous conventional endoscopic attempts, and offers an alternative approach to surgical intervention.

Algorithm for detection of small-bowel metastasis in malignant melanoma of the skin

BACKGROUND AND STUDY AIM

The aim of this study was to develop an algorithm to detect small-bowel metastasis (SBM) of melanoma by sequential laboratory parameters and pan-intestinal endoscopy (PIE) including video capsule endoscopy (VCE).

PATIENTS AND METHODS

A total of 390 melanoma patients (AJCC stage I/II/III/IV, 140/80/121/49) were screened for signs of intestinal blood loss (fecal occult blood test [FOBT] or overt bleeding) in an open, multicenter, prospective study, and those who were positive underwent PIE. Independent of the presence of intestinal bleeding, all stage IV patients were offered PIE. Follow-up was obtained in 357 patients (91.5 %) for a median of 16 months. We undertook to identify possible associations between SBM and clinical and laboratory data. Survival data were analyzed with regard to clinical and laboratory data and small-bowel findings.

RESULTS

Intestinal blood loss was suspected in 49 of 390 patients (12.6 %), 38 of whom (77.6 %) agreed to undergo endoscopy. In 10 patients, SBM was detected by VCE (intention-to-diagnose, 20.4 %; AJCC III, n = 2; AJCC IV, n = 8). The SBM was resected in five patients. Total detection rates of SBM were 14 of 49 patients in stage IV (28.6 %, intention-to-diagnose), 2 of 121 in stage III (1.7 %), and 0 in stage I/II. In FOBT-positive patients, SBM detection rates were 72.7 %, 14.3 %, and 0 % in tumor stages IV, III, and I/II, respectively. Positive FOBT proved to be an independent negative prognostic factor for total survival in stage III and IV melanoma.

CONCLUSIONS

SBMs are frequent in advanced melanoma. In stage III patients, screening for intestinal blood loss by PIE may help to identify SBMs. In stage IV, indication for PIE should depend on the individual consequences of detecting SBM, but not on bleeding symptoms alone.

Lipopolysaccharide binding protein, interleukin-6 and C-reactive protein in acute gastrointestinal infections: value as biomarkers to reduce unnecessary antibiotic therapy

AIM

Several new biomarkers, such as lipopolysaccharide binding protein (LBP) and interleukin-6 (IL-6), have the potential to determine the severity and outcome of infectious diseases. LBP and IL-6 serum levels have not been reported in patients with gastrointestinal infections. The aim of this study was to compare established markers of infection with new markers, such as LBP and IL-6, in patients with acute gastrointestinal infections

METHOD

LBP, C-reactive protein (CRP), white blood cell count (WBC) and IL-6 serum levels were determined in patients with acute viral or bacterial (positive stool cultures) gastroenteritis. The final diagnosis and empiric antibiotic use were recorded. In total, medical data on 88 patients with acute gastroenteritis (22 bacterial, 66 viral or nonspecific) were analyzed.

RESULTS

LBP and CRP levels were significantly increased in patients with acute bacterial gastroenteritis [28.5 ± 16.5 vs. 15.2 ± 11.5 μg/mL (p < 0.05) and 10.4 ± 9.6 vs. 3.8 ± 5.5 mg/dL (p < 0.001), respectively]. LBP at a cut-off value of 14.6 μg/mL and CRP at a cut-off value of 1.7 mg/dL distinguished between bacterial and non-bacterial gastrointestinal infection (receiver operator characteristic analysis). Empiric antibiotic therapy was initiated in 82% of patients with bacterial gastroenteritis and in 27% of patients with viral gastroenteritis.

CONCLUSION

The use of the cut-off values for LBP and CRP determined here would have avoided unnecessary antibiotic therapy in 14 and 11%, of patients respectively. CRP and LBP appear to be superior to IL-6 and WBC as diagnostic markers of bacterial gastrointestinal infection. Cut-off values may be a useful tool to support clinical decision-making on whether or not to initiate empiric antibiotic therapy.

Pantoprazole induces severe acute hepatitis

A female patient receiving pantoprazole during a corticosteroid therapy for encephalomyelitis disseminata developed severe acute hepatitis one month after initiation of pantoprazole treatment. Other causes of hepatic dysfunction including viral hepatitis, autoimmune hepatitis, primary sclerosing cholangitis, primary biliary cirrhosis, haemochromatosis or Wilson's disease were excluded. Liver biopsy showed severe hepatic lesions with extensive necroses of the parenchyma. One week after discontinuation of pantoprazole the liver function began to improve and gradually the patient fully recovered. One year earlier the patient had been treated with pantoprazole before and had developed a milder form of hepatitis then. This case argues for an idiosyncratic hepatocellular damage caused by pantoprazole.

[Wilson disease--evaluation of disease-related topics through the eyes of patients by patient-generated paintings--a cooperative study with the German patient organisation Verein morbus Wilson e. V]

BACKGROUND

The importance of disease-related topics can vary widely between patients and doctors. Patient organisations such as the German Verein Morbus Wilson e. V. can overcome this discrepancy. The goal of the present cooperative study was the collection of topics important to Wilson patients by asking patients to generate paintings about their disease.

METHODS

Patients with Wilson disease were asked by mail to draw paintings about their disease and to donate them to the Verein Morbus Wilson e. V.

RESULTS

32 paintings from 27 patients were donated. The majority of the patients added written comments to their art work. Disease-related topics included in the paintings were as follows: psychological work-up of the disease 33 % (n = 11), presentation of affected organs (liver/brain) 22 % (n = 6), therapy 19 % (n = 5), diagnostic path 15 % (n = 4), inheritance 15 % (n = 4), copper-related diet 11 % (n = 3). 33 % (n = 11) of the paintings were composed of two parts reflecting before and after the disease or presenting the individual time course of the disease.

CONCLUSION

Psychological aspects of disease acceptance are the prominent topic in the paintings. The timepoint of diagnosis is experienced as major change in life. The paintings enable both the patient organisation and the caretakers to put more focus on the psychological aspects of the disease. Asking for paintings opens a new channel for patient-physician contacts and produces a feeling of interest and competence in patients.

Thyroid morphology and function after surgical treatment of thyroid diseases

In 1992 we performed a prospective study with 300 patients after thyroid resection. Indication for the operation was a benign nodular goiter in 280 cases, Graves' disease in 11 cases and a differentiated thyroid carcinoma in 9 cases. 269 patients (89.6%) returned for a follow-up visit which contained an ultrasound of the thyroid region and a determination of the serum thyrotropin concentration. Patients with less than 10 ml had a thyroxine replacement of 100 yg daily for six months. This therapy was discontinued for the next three months and they received their follow-up nine months after the operation. All other patients with benign diseases had their follow-up without thyroxine replacement eight weeks after the operation. The mean remnant volume was 2.4 ml for selective resected lobes, 0.8 ml after near total resection and 0.2 ml after lobectomy. We found residual or recurrent nodular tissue in 7.2% of the partially resected lobes. Visualization of the recurrent nerve and ligation of the inferior thyroid artery reduced the risk of nodular tissue in the remnant thyroid tissue significantly. Only 153 patients (62%) were treated according to our postoperative treatment schedule. Thyroxine replacement therapy was given to 96 patients at the time of their follow-up. 34% of the patients without replacement therapy had signs of insufficient hormone production of the remnant thyroid tissue. However, 22% of the patients under thyroxine replacement therapy showed signs of iatrogenic subclinical hyperthyroidism. We found a significant correlation between the volume of the remnant tissue and the serum thyrotropin concentration in patients without continuous thyroxine replacement. The corresponding calculated volume for a functionally potent remnant thyroid volume was 7.3 ml. This value was significantly higher in patients with both inferior thyroid arteries ligated at 9.8 ml. An individual postoperative therapy with iodine and/or thyroxine, which results in neither a high rate of thyrotropin elevation nor an unnescessary and undesirable part of the patients with suppressed serum thyrotropin concentrations is an indispensable component of the surgical treatment of benign nodular thyroid disease in areas of endemic iodine deficiency. As a result of this study we changed our postoperative treatment schedule. Patients with less than 10 ml remnant thyroid volume will have a continuous replacement therapy with a reduced dose of 75 yg thyroxine daily.

Fatal varicella in an immunocompromised adult associated with a European genotype E2 variant of varicella zoster virus

Varicella zoster virus (VZV) seronegative patients under immunosuppressive therapy are at risk for severe life-threatening varicella. A 25-year-old male patient presented with rash and hepatitis. He had been known to suffer from Crohn's disease and received immunosuppressive treatment with azathioprine. The patient showed dyspnoea, and presented with a generalized rash with vesicular lesions typical for herpesvirus infections. He was started immediately on acyclovir therapy. Varicella infection was determined in this VZV seronegative patient in rash vesicles, blood and tracheal secretions and a high VZV viral load was detected in these specimens. The causative agent was genotyped by sequencing of several genes as a variant of the European genotype E2 containing several unique single nucleotide polymorphisms. Despite all measures, there was progressive septic shock, and the patient died due to multi-organ failure. Immunocompromised adults without varicella history are at high risk to develop life-threatening complications of varicella. Antiviral therapy with acyclovir can only be successful when administered as early as possible on suspicion of varicella infection in this group of patients. The most effective method to prevent severe varicella in immunocompromised patients is active immunization prior to immunosuppressive therapy.

[Hemoptysis and acute renal failure in a 29-year-old patient with chronic hepatitis C infection]

A 29-year-old male patient with chronic hepatitis C infection and interferon alpha therapy in his medical history was admitted to the hospital because of the clinical manifestation of a pulmonary renal syndrome. High titers of proteinase-3-ANCA were detected, while an infectious agent was ruled out. After diagnosis of Wegener's granulomatosis the patient received prednisolone and cyclophosphamide pulse therapy and remission developed rapidly. Chronic hepatitis C infection as well as interferon therapy are frequently associated with autoimmune disorders. We assume that the interferon therapy itself has triggered autoimmune processes resulting in Wegener's granulomatosis in our patient. Thus we recommend to search specifically for autoimmune disorders in the past medical history and if necessary to consider a screening for autoantibodies before starting an interferon therapy. An autoimmune disease should also be taken into account if new symptoms develop under an ongoing interferon alpha therapy.

Regulatory CD4+ CD25+ T cells prevent thymic dysfunction in experimental chronic colitis

Chronic colitis in T-cell deficient Tg epsilon26 mice develops due to a dysfunction of the thymus which generates colitogenic T cells after bone marrow (BM) transplantation. Regulatory CD4+ CD25+ T cells have been shown to prevent colitis in this model by normalizing the peripheral T-cell pool. We tested the hypothesis that T-cell normalization takes place in the thymus. Tg epsilon26 mice were transplanted with BM (BM-->Tg epsilon26 mice) and consequently received either CD4+ CD25+ or CD4+ CD25- cells from syngenic wild type mice. Furthermore, untransplanted Tg epsilon26 mice received CD4+ CD25+ or CD4+ CD25- cells or complete mesenteric lymph node cells. Transfer of regulatory. CD4+ CD25+ cells normalized the total number of thymocytes and the percentage and number of double positive CD4+ CD8+ cells in transplanted mice while percentage of single positive CD4+ and CD8+ thymocytes in BM-->Tg epsilon26 mice was reduced upon CD4+ CD25+ transfer. Timing of CD4+ CD25+ cell injection was important as transfer later than 7 days after BM transplantation failed to prevent abnormal thymic T-cell distribution in BM-->Tg epsilon26 mice. Isolated CD4+ CD25+ cell transfer without preceding BM transplantation failed to reconstitute thymic architecture. Differences of thymic cell composition could not be exclusively explained by presence or absence of colitis, respectively, because 19 days after BM transplantation when both groups showed no histological signs of colitis, animals transferred with CD4+ CD25+ T cells had a significantly higher percentage and number of CD4+ CD25+ thymocytes and CD4+ Foxp3+ cells than BM-->Tg epsilon26 mice. In conclusion, early CD4+ CD25+ cotransfer prevents thymic dysfunction which underlies immune-mediated bowel inflammation in BM-->Tg epsilon26 mice.

The satiety factor apolipoprotein A-IV modulates intestinal epithelial permeability through its interaction with alpha-catenin: implications for inflammatory bowel diseases

INTRODUCTION

Apolipoprotein A-IV (apoA-IV), an intestinally and cerebrally synthesized satiety factor and anti-atherogenic plasma apolipoprotein, was recently identified as an anti-inflammatory protein. In order to elucidate whether intestinal apoA-IV exerts similar repair function as its hepatic homologue apolipoprotein A-V (apoA-V), apoA-IV-interactive proteins were searched and in vitro functional studies were performed with apoA-IV overexpressing cells. ApoA-IV was also analyzed in the intestinal mucosa of patients with inflammatory bowel diseases (IBD), together with other genes involved in epithelial junctional integrity.

METHODS

A yeast-two-hybrid screening was used to identify apoA-IV-interactors. ApoA-IV was overexpressed in Caco-2 and HT-29 mucosal cells for colocalization and in vitro epithelial permeability studies. Mucosal biopsies from quiescent regions of colon transversum and terminal ileum were subjected to DNA-microarray analysis and pathway-related data mining.

RESULTS

Four proteins interacting with apoA-IV were identified, including apolipoprotein B-100, alpha1-antichymotrypsin, cyclin C, and the cytosolic adaptor alpha-catenin, thus linking apoA-IV to adherens junctions. Overexpression of apoA-IV was paralleled with a differentiated phenotype of intestinal epithelial cells, upregulation of junctional proteins, and decreased paracellular permeability. Colocalization between alpha-catenin and apoA-IV occurred exclusively in junctional complexes. ApoA-IV was downregulated in quiescent mucosal tissues from patients suffering from IBD. In parallel, only a distinct set of junctional genes was dysregulated in non-inflamed regions of IBD gut.

CONCLUSIONS

ApoA-IV may act as a stabilizer of adherens junctions interacting with alpha-catenin, and is likely involved in the maintenance of junctional integrity. ApoA-IV expression is significantly impaired in IBD mucosa, even in non-inflamed regions.

Second-line chemotherapy in advanced pancreatic cancer: A retrospective, single-center analysis

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Background: Patients with advanced pancreatic cancer profit from palliative chemotherapy. The role of second-line chemotherapy is not yet established. Methods: We performed a retrospective analysis in 98 patients who were treated at our department from 1/2004–6/2006 due to locally advanced or metastatic adenocarcinoma of the pancreas. Results: At the time of analysis 67 patients had died (median overall survival 9 months), 31 patients are still alive (median follow up 9 months). 12 patients were initially treated with radiochemotherapy. 86 patients received systemic chemotherapy; 43 of these patients were treated with second-line chemotherapy after disease progression. OS was significantly longer in patients who received second-line chemotherapy (10 months versus 5.0 months, p=0.023). Response to second-line chemotherapy was partial remission in 2 patients (4.6 %), stable disease in 18 patients (44.8 %), and progressive disease in 19 patients (44.2 %), in 3 patients the treatment was stopped due to toxicity (6.9 %). 12 patients received second-line treatment after early disease progression under first-line chemotherapy. 9 of these patients did not respond to second-line treatment, 2 achieved stable disease and 1 patient had partial remission. Elevated LDH and CA19.9 serum levels at the time of diagnosis were identified as negative prognostic factors. Conclusions: Prognosis of patients with advanced pancreatic cancer is still poor. Selected patients may benefit from salvage chemotherapy after failure of first-line chemotherapy.

No significant financial relationships to disclose.

Development of a heterologous, multigenotype vaccine against hepatitis C virus infection

BACKGROUND

Unquestionably viral diversity and genetic heterogeneity in hepatitis C virus (HCV) infection and other viral diseases play an essential role in viral immune escape and the development of chronicity. Despite this knowledge most vaccine approaches against HCV have excluded this important issue. Moreover the feasibility of developing an effective HCV vaccine has been questioned, mainly because prophylactic immunity against HCV cannot be achieved in chimpanzees by either vaccination or previous HCV infection, and reinfection in men has been reported, most likely due to genetic shift and immune escape. To analyse and characterize a new technique of a 'multigenotype'- and/or 'library'-vaccine, we established an envelope 1 (E1) plasmid vaccine against HCV and characterized humoral and cellular immune responses after vaccination in a mouse model.

MATERIAL AND METHODS

Normally genetic information of one or two target proteins is cloned into a DNA-vaccine. In our approach we cloned a defined number of different genotypes and subtypes (defined vaccine, DV) or the genetic information from 20 patients (undefined) into a plasmid (library vaccine, LV).

RESULTS

As expected, immunized animals showed both stronger humoral (ELISA) and cellular (T-cell proliferation, ELISPOT) immune responses against genotype 1, since the stimulating antigen was genotype 1 derived. However, not all genotype 1 immunized animals recognized this viral antigen leading to the assumption that some epitopes lost their immunogenicity through a change in the amino acid sequence. Interestingly, some of the genotype 4 and 5 immunized mice sera were able to react against E1 protein.

CONCLUSION

Most of the assays showed immune reactivity against the DV or LV vaccine demonstrating the cross-reactive potential of such a vaccination approach. This cloning and immunization strategy based on the viral heterogeneity of the virus has in our view major implications for HCV, a virus with a broad viral genetic diversity, and may become in the future in the context of DNA- or viral-based vaccination strategies a possibility to overcome viral immune escape both in the prophylactic or therapeutic setting.

Helicobacter pylori-induced apoptosis in T cells is mediated by the mitochondrial pathway independent of death receptors

BACKGROUND

Chronic infection with Helicobacter pylori is related to the pathogenesis of the noncardia carcinoma of the stomach. In this study we investigated the mechanisms of H. pylori-induced apoptosis in T lymphocytes, which could explain a mechanism of immune evasion facilitating chronic inflammation of the mucosa and gastric carcinogenesis.

MATERIALS AND METHODS

The supernatant of H. pylori culture was used to study the mechanism of apoptosis induction in human leukaemia T cell lines Jurkat and CEM and in primary T cells. The cytotoxin associated gene A (CagA) and vacuolating cytotoxin A (Vac A) positive bacterial strain H. pylori 60190 (CagA(+), VacA(+)) and as a control the less toxic H. pylori strain Tx30a (CagA(-), VacA(-)) were used to produce the supernatant. Cell death was determined by DNA fragmentation and protein expression by Western blot.

RESULTS

H. pylori 60190-induced apoptosis was neither blocked by inhibition of the death ligands TRAIL (TNF-related apoptosis-inducing ligand), CD95L/FasL and TNF-alpha (tumour necrosis factor-a) in wild type Jurkat cells nor in FADD(def) (Fas-associated death domain protein) and caspase-8(def) subclones of the Jurkat cell line. Yet, the pancaspase inhibitor zVAD-fmk could inhibit up to 90% of H. pylori-induced apoptosis. Stable transfection of Jurkat wild type cells with Bcl-x(L and) Bcl-2 resulted in marked reduction of H. pylori-induced apoptosis, showing that the mitochondrial pathway is the key regulator. This is supported by the finding that surviving primary human lymphocytes upregulate Bcl-2 when exposed to H. pylori supernatant.

CONCLUSIONS

H. pylori-induced apoptosis of T cells is mediated by the mitochondrial pathway and could create a local environment that facilitates life-long infection by immune evasion.

Liver and Iron Metabolism - A Comprehensive Hypothesis for the Pathogenesis of Genetic Hemochromatosis

It is hypothesized that a homozygous C282Y mutation of the HFE gene prohibits the assembly of the transferrin-receptor 1 (TFR1) with the divalent metal transporter (DMT1) as the main iron update complex in hepatocytes membrane. Thus, the cellular influx of transferrin-bound iron from the endosomal compartment into the cytasol is compromised. As a consequence, transferrin saturation increases while concomitantly a cytosolic iron deficiency state develops. This in turn triggers the suppression of hepcidin synthesis in hepatocytes. Its impaired release into the bloodstream, causes the increased intestinal iron absorption of hemochromatosis. Excessively absorbed iron cannot be used by the erythron as a surplus for hemoglobin synthesis and is therefore trapped in ferritin complexes of RES macrophages. The ferritin is thereafter released into the bloodstream and taken up by hepatocytes for final disposal. In the lysosomal compartment ferritin is degraded to hemosiderin. Here, the release of excessive iron molecules may induce cellular injury via free radicals. The phenotypic expression of genetic hemochromatosis may depend on the activity of the erythron to use transferrin-bound-iron for heme synthesis. Therefore, a high erythron requirement for iron can utilize excess iron and may represent the rationale of phlebotomy therapy in this disease.

Clinical presentation, diagnosis and long-term outcome of Wilson's disease: a cohort study

BACKGROUND

Wilson's disease is a rare inborn disease related to copper storage, leading to liver cirrhosis and neuropsychological deterioration. Clinical data on larger cohorts are limited owing to low disease frequency.

OBJECTIVE AND METHODS

We performed a retrospective analysis of 163 patients with Wilson's disease, examined at the University of Heidelberg, Heidelberg, Germany, to determine clinical presentation, diagnostic course and long-term outcome.

RESULTS

Diagnostic criteria for non-caeruloplasmin-bound serum copper, serum caeruloplasmin, 24-h urinary copper excretion, liver copper content, presence of Kayser-Fleischer rings and histological signs of chronic liver damage were reached in 86.6%, 88.2%, 87.1%, 92.7%, 66.3% and 73% of patients, respectively. By analysis of the coding region of ATP7B (except exons 2, 3 and 21), disease-causing mutations were detected in 57% and 29% of patients with Wilson's disease on both chromosomes and on one chromosome, respectively. No mutations were detected in 15% of patients with Wilson's disease. No significant differences were found in clinical parameters or initial presentation between patients grouped according to their mutations. The patients with neurological symptoms were significantly older at the onset of symptoms than patients with hepatitic symptoms (20.2 v 15.5 years of age, p<0.05), and the neurological symptoms were associated with a significantly longer time from onset to diagnosis than hepatic symptoms (44.4 v 14.4 months, p<0.05). After initiating treatment, 76.1% of the patients had a stable or improved course of the disease. Disease progression under treatment was more likely for neuropsychiatric than for hepatic symptoms. Side effects of treatment occurred in 74.4% of patients.

CONCLUSIONS

Patients with Wilson's disease having predominantly neuropsychiatric symptoms manifest symptoms later, have a longer time delay from onset of symptoms until definitive diagnosis and have a poorer outcome than patients with hepatic symptoms.

Prophylactic and therapeutic vaccination with dendritic cells against hepatitis C virus infection

Antigen uptake and presentation capacities enable DC to prime and activate T cells. Recently, several studies demonstrated a diminished DC function in hepatitis C virus (HCV) infected patients showing impaired abilities to stimulate allogenic T cells and to produce IFN-gamma in HCV infected patients. Moreover, DC of patients who have resolved HCV infection behave like DC from healthy donors responding to maturation stimuli, decrease antigen uptake, up-regulate expression of appropriate surface marker, and are potent stimulators of allogenic T cells. A number of studies have demonstrated in tumour models and models of infectious diseases strong induction of immune responses after DC vaccination. Because DC are essential for T-cell activation and since viral clearance in HCV infected patients is associated with a vigorous T-cell response, we propose a new type of HCV vaccine based on ex vivo stimulated and matured DC loaded with HCV specific antigens. This vaccine circumvents the impaired DC maturation and the down regulated DC function of HCV infected patients in vivo by giving the necessary maturation stimuli and the HCV antigens in a different setting and location ex vivo. Strong humoral and cellular immune responses were detected after HCV core DC vaccination. Furthermore, DC vaccination shows partial protection in a therapeutic and prophylactic model of HCV infection. In conclusion, mice immunized with HCV core pulsed DC generated a specific antiviral response in a mouse HCV challenge model. Our results indicate that HCV core pulsed DC may serve as a new modality for immunotherapy of HCV especially in chronically infected patients.

TAp73/Delta Np73 influences apoptotic response, chemosensitivity and prognosis in hepatocellular carcinoma

We investigated the mechanisms by which TAp73 beta and dominant-negative p73 (Delta Np73) regulate apoptosis. TAp73 beta transactivated the CD95 gene via the p53-binding site in the first intron. In addition, TAp73 beta induced expression of proapoptotic Bcl-2 family members and led to apoptosis via the mitochondrial pathway. Endogenous TAp73 was upregulated in response to DNA damage by chemotherapeutic drugs. On the contrary, DeltaNp73 conferred resistance to chemotherapy. Inhibition of CD95 gene transactivation was one mechanism by which DeltaNp73 functionally inactivated the tumor suppressor action of p53 and TAp73 beta. Concomitantly, DeltaNp73 inhibited apoptosis emanating from mitochondria. Thus, DeltaNp73 expression in tumors selects against both the death receptor and the mitochondrial apoptosis activity of TAp73 beta. The importance of these data is evidenced by our finding that upregulation of DeltaNp73 in hepatocellular carcinoma patients correlates with reduced survival. Our data indicate that Delta Np73 is an important gene in hepatocarcinogenesis and a relevant prognostic factor.

HJV gene mutations in European patients with juvenile hemochromatosis

A large variety of mutations within the genes encoding hepcidin (HAMP) and hemojuvelin (HJV) have been identified in patients with the severe iron overload disorder juvenile hemochromatosis (JH). The aim of the present study was to evaluate the molecular background of JH in patients from central parts of Europe. Sequence analyses of HAMP and HJV were performed in seven JH patients from six families from Germany, Slovakia, and Croatia. For detection of the G320V mutation in HJV, a rapid polymerase chain reaction-based assay was developed. No mutations were found within the HAMP gene. Six of seven (86%) JH patients carried at least one copy of the G320V mutation within the HJV gene. Four of these patients were homozygous for the G320V mutation. In addition, two novel HJV mutations were identified (C119F and S328fsX337). Taken together, the present study demonstrates that molecular analysis of the HJV gene is a powerful tool for an early and reliable diagnosis of JH. As in affected patients from Greece, the G320V mutation seems to be widely distributed among JH patients from central parts of Europe. Therefore, detection of the G320V mutation could identify the majority of JH cases from these regions non-invasively.

Retarded release phosphatidylcholine benefits patients with chronic active ulcerative colitis

BACKGROUND AND AIMS

We examined the hypothesis of an anti-inflammatory effect of phosphatidylcholine in ulcerative colitis.

METHODS

A phase IIA, double blind, randomised, placebo controlled study was performed in 60 patients with chronic active, non steroid dependent, ulcerative colitis, with a clinical activity index (CAI) of > or = 4. Retarded release phosphatidylcholine rich phospholipids and placebo were administered at a dose of 6 g daily over three months. The primary end point was a change in CAI towards clinical remission (CAI < or = 3) or CAI improvement by > or = 50%. Secondary end points included > or = 50% changes in endoscopic activity index (EAI), histology, and quality of life scores.

RESULTS

Induction of clinical remission (CAI < or = 3) as the primary outcome variable was attained by 16 (53%) patients in the phosphatidylcholine treated group compared with three (10%) in the placebo group (p<0.00001). The rate of clinical remission and CAI improvement was 90% in the phosphatidylcholine group and only 10% in the placebo group. A median drop of seven points in the CAI score (70% improvement) was recorded in the phosphatidylcholine group compared with no change in the placebo group. Secondary end point analysis revealed concomitant drops in EAI and histology scores (p = 0.00016 and p = 0.0067 compared with placebo, respectively). Improvement in quality of life was reported by 16 of 29 evaluated patients in the phosphatidylcholine group compared with two of 30 in the placebo group (p = 0.00005).

CONCLUSION

Retarded release oral phosphatidylcholine is effective in alleviating inflammatory activity caused by ulcerative colitis.

[A young diabetic with small-nodule liver cirrhosis, high transferrin saturation and negative HFE test]

HISTORY

A 28 year young female presented to our hospital for further evaluation with recently diagnosed diabetes mellitus, hyperpigmentation of the skin, hepato- and splenomegaly, thrombocytopenia and an elevated transferrin saturation (96 %), but a negative test for HFE gene mutations such as C282Y and H63D.

FINDINGS

Using the mini-laparascopic technique we diagnosed a smallnodular liver cirrhosis with an iron overload.

DIAGNOSIS AND TREATMENT

This is the clinical presentation of one subtype of the so called Non-HFE-hemochromatosis, the juvenile hemochromatosis (HFE2). Other causes of primary and secondary iron overload have been ruled out. Different from the HFE-positive hemochromatosis (HFE 1) in which the gene defect is located on chromosome 6, the defect in HFE 2 is located on chromosome 1. The underlying genetic defect has been localized within recently identified HJV gene. Phlebotomy is the treatment of choice, to be performed until the ferritin level is lower than 50 microg/l.

CONCLUSIONS

If liver cirrhosis is present in hemochromatosis, the overall risk of developing heptatocellular carcinoma is 20 times higher than in the normal population. Therefore it is suggested to perform an ultrasound examination of the liver and an AFP-test every 6 months, whereas an MRI-scan should be performed once a year, as a basis for further treatment options.

Integriertes Skills-Lab-Konzept für die studentische Ausbildung in der Inneren Medizin

BACKGROUND AND OBJECTIVE

An amendment to the German medical curriculum in April 2002 will place basic practical skills at the centre of medical training. We report here on the implementation and evaluation of an obligatory, tutor-guided, and integrated skills laboratory concept in the field of internal medicine.

METHODS

To test the effectiveness of a skills laboratory training on OSCE performance a pilot study was carried out. The experimental group, of 77 students, participated in seven sessions of communication training, skills laboratory training, and bedside teaching, each lasting one and a half hours. The control group of 66 students had as many sessions but was only offered bedside-teaching. The evaluation of acceptance of skills' training as well as the related increase in individual competence is on-going (summer term 2004: n = 176 students).

RESULTS

The integrated skills laboratory concept was rated at 3.5 (SD = 1.2) on a 5-point scale and was acknowledged as practice-oriented (M = 4.2; SD = 1.0) and relevant for doctors' everyday lives (M = 3.6; SD = 1.1). Increased levels of competence according to individual self-evaluations proved to be highly significant (p<.001), and results of the pilot study showed that the experimental group had a significantly better OSCE performance than the control group (p<.001).

CONCLUSION

This pilot study shows that curriculum changes promoting basic clinical skills are effective and lead to an improved practical education of tomorrow's physicians. The integrated skills laboratory concept is well accepted and leads to a relevant increase in competence in the practice of internal medical. The presented skills laboratory concept in internal medicine is proving to be a viable and efficient learning tool.

Enhanced caspase-8 recruitment to and activation at the DISC is critical for sensitisation of human hepatocellular carcinoma cells to TRAIL-induced apoptosis by chemotherapeutic drugs

Tumour necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) exhibits potent antitumour activity upon systemic administration in mice without showing the deleterious side effects observed with other apoptosis-inducing members of the TNF family such as TNF and CD95L. TRAIL may, thus, have great potential in the treatment of human cancer. However, about 60% of tumour cell lines are not sensitive to TRAIL. To evaluate the mechanisms of tumour resistance to TRAIL, we investigated hepatocellular carcinoma (HCC) cell lines that exhibit differential sensitivity to TRAIL. Pretreatment with chemotherapeutic drugs, for example, 5-fluorouracil (5-FU), rendered the TRAIL-resistant HCC cell lines sensitive to TRAIL-induced apoptosis. Analysis of the TRAIL death-inducing signalling complex (DISC) revealed upregulation of TRAIL-R2. Caspase-8 recruitment to and its activation at the DISC were substantially increased after 5-FU sensitisation, while FADD recruitment remained essentially unchanged. 5-FU pretreatment downregulated cellular FLICE-inhibitory protein (cFLIP) and specific cFLIP downregulation by small interfering RNA was sufficient to sensitise TRAIL-resistant HCC cell lines for TRAIL-induced apoptosis. Thus, a potential mechanism for TRAIL sensitisation by 5-FU is the increased effectiveness of caspase-8 recruitment to and activation at the DISC facilitated by the downregulation of cFLIP and the consequent shift in the ratio of caspase-8 to cFLIP at the DISC.

Severe rhabdomyolysis and renal failure triggered by a sauna visit in sickle cell trait: a case report

Sickle cell trait (SCT) is an usually asymptomatic hemoglobinopathy. Cases of sudden excertional deaths in individuals with SCT have been described. We here report an exceptional case of excessive rhabdomyolysis and acute renal failure triggered by a sauna visit in a 29 year-old African American with SCT.

Regulatory CD4+CD25+ cells reverse imbalances in the T cell pool of bone marrow transplanted TGepsilon26 mice leading to the prevention of colitis

BACKGROUND AND AIMS

Erroneous thymic selection of developing T lymphocytes may be responsible for the expansion of self reactive T cells or may contribute to the absence of regulatory T cells important in controlling peripheral inflammatory processes. Colitis in bone marrow (BM) transplanted Tgepsilon26 mice is induced by abnormally activated T cells developing in an aberrant thymic microenvironment. We investigated the protective role of regulatory CD4+CD25+ T cells in this model.

METHODS

BM from (C57BL/6 x CBA/J) F1 mice was transplanted into specific pathogen free Tgepsilon26 mice (BM-->Tgepsilon26). Transplanted mice received no cells (control), sorted CD4+CD25+, or CD4+CD25- cells from mesenteric lymph nodes (MLN) of normal mice. MLN cell subsets were analysed using membrane markers. Cytokine secretion of MLN cells was measured using intracellular cytokine staining and cytokine secretion in anti-CD3 stimulated cell cultures. Colitis was measured by histological scores.

RESULTS

CD4+CD25+ cells were reduced in the MLNs of BM-->Tgepsilon26 mice. Transfer of regulatory CD4CD4+CD25+ but not of CD4+CD25- cells reduced the number of MLN CD4+ T cells in BM-->Tgepsilon26 recipients and increased the number of MLN CD8+ cells, thereby normalising the CD4+/CD8+ ratio. CD4+CD25+ but not CD4+CD25- cell transfer into BM-->Tgepsilon26 mice reduced the number of tumour necrosis factor alpha+ CD4+ cells and increased the secretion of transforming growth factor beta by MLN cells. Transfer of 3 x 10(5) CD4+CD25+ cells after BM transplantation into Tgepsilon26 mice prevented colitis whereas CD4+CD25- cells had no protective effect.

CONCLUSIONS

These results suggest that defective selection or induction of regulatory T cells in the abnormal thymus is responsible for the development of colitis in BM-->Tgepsilon26 mice. Transfer of CD4+CD25+ cells can control intestinal inflammation in BM-->Tgepsilon26 mice by normalising the number and function of the MLN T cell pool.

The iron-regulatory peptide hormone hepcidin: expression and cellular localization in the mammalian kidney

It is generally accepted that iron homeostasis is mainly controlled in the gastrointestinal tract by absorption of dietary iron. However, recent studies have shown that the kidneys are also involved in iron metabolism. Since the iron-regulatory and antimicrobial peptide hormone hepcidin was originally isolated from human urine we have investigated the expression as well as the zonal and cellular localization of hepcidin in the mammalian kidney and developed an ELISA assay to analyze hepcidin concentrations in serum and urine. The expression of hepcidin was shown by RT-PCR and immunoblot experiments; its cellular localization was studied by immunocytochemistry in human, mouse and rat kidney, which revealed similar patterns of immunoreactivity. Hepcidin expression was absent from the proximal tubule and descending and ascending thin limbs. There was strong expression in the thick ascending limb of the cortex and in connecting tubules. Moderate expression was noted in the thick ascending limb and collecting ducts of the medulla and in collecting ducts of the papilla. Importantly, the cells of the macula densa were unstained. At the cellular level, hepcidin was localized to the apical cell pole of the renal epithelial cells. Based on its presence in urine, hepcidin may be released apically into the urine. Enhanced levels of hepcidin were determined in patients with chronic renal insuffciency (156.8 ng/ml, controls 104.2 ng/ml) indicating that the kidneys may metabolize and/or eliminate the circulating peptide. From the expression of hepcidin in the mammalian kidney, we have concluded that the iron-regulatory hormone is an intrinsic renal peptide which is not only eliminated by the kidney but is also synthesized in the kidney tubular system. Localization of hepcidin in the kidney implicates an iron-regulatory role of this peptide hormone in the renal tubular system, possibly in connection with the iron transporter divalent metal transporter-1.