Static cold storage compared with normothermic machine perfusion of the liver and effect on ischaemic-type biliary lesions after transplantation: a propensity score-matched study.

BACKGROUND: Given the susceptibility of organs to ischaemic injury, alternative preservation methods to static cold storage (SCS), such as normothermic machine perfusion (NMP) are emerging. The aim of this study was to perform a comparison between NMP and SCS in liver transplantation with particular attention to bile duct lesions. METHODS: The outcomes of 59 consecutive NMP-preserved donor livers were compared in a 1 : 1 propensity score-matched fashion to SCS control livers. Postoperative complications, patient survival, graft survival and bile duct lesions were analysed. RESULTS: While patients were matched for cold ischaemia time, the total preservation time was significantly longer in the NMP group (21 h versus 7 h, P < 0.001). Patient and graft survival rates at 1 year were 81 versus 82 per cent (P = 0.347) and 81 versus 79 per cent (P = 0.784) in the NMP and SCS groups, respectively. The postoperative complication rate was comparable (P = 0.086); 37 per cent NMP versus 34 per cent SCS patients had a Clavien-Dindo grade IIIb or above complication. There was no difference in early (30 days or less) (NMP 22 versus SCS 19 per cent, P = 0.647) and late (more than 30 days) (NMP 27 versus SCS 36 per cent, P = 0.321) biliary complications. However, NMP-preserved livers developed significantly fewer ischaemic-type bile duct lesions (NMP 3 versus SCS 14 per cent, P = 0.047). CONCLUSION: The use of NMP allowed for a significantly prolonged organ preservation with a lower rate of observed ischaemic-type bile duct lesions.

Autologous stem cell transplantation following simultaneous liver and kidney transplantation in severe amyloid light chain amyloidosis associated with multiple myeloma: a case report.

INTRODUCTION: The involvement of vital organs in multiple myeloma (MM) with systemic amyloid light-chain (AL) amyloidosis can lead to acute organ failure. In this case, the fear of recurrence or progression of multiple myeloma often excludes those patients from undergoing organ transplantation. Nevertheless, clinically fit patients might benefit from a different therapeutic approach. This case presentation might highlight this particular unmet need and strengthen a different treatment approach. CASE PRESENTATION: To our knowledge, we present the first case of successful simultaneous liver and kidney transplantation, followed by autologous stem cell transplantation in a 60-year-old Caucasian male patient suffering from MM (Durie-Salmon stage IIB; ISS-stage: III, RISS stage: III) with primary AL amyloidosis. Chemotherapy treatment led to end-stage kidney disease requiring dialysis. Liver failure also occurred after at least three cycles of CyBorD (bortezomib, cyclophosphamide, and dexamethasone) of induction therapy with a good hematologic response. Over three years after the initial diagnosis, the patient is reportedly showing an excellent quality of life and a complete remission. DISCUSSION AND CONCLUSION: We conclude that kidney and liver transplantation followed by autologous stem cell transplantation can be a treatment option for a selected group of patients with MM if AL amyloidosis is leading. In the end, the remission assessment by IMWG response criteria displayed a complete remission of MM together with complete reconstitution of organ functions (liver & renal function) as long as upfront clinical evaluation excludes significant cardiac involvement and other severe co-morbidities.

Evaluation of liver iron overload with R2* relaxometry with versus without fat suppression: both are clinically accurate but there are differences.

OBJECTIVES: To assess clinically relevant difference in hepatic iron quantification using R2* relaxometry with (FS) and without (non-FS) fat saturation for the evaluation of patients with suspected hepatic iron overload. METHODS: We prospectively enrolled 134 patients who underwent 1.5-T MRI R2* relaxometry with FS and non-FS gradient echo sequences (12 echoes, initial TE = 0.99 ms). Proton density fat fraction for the quantification of steatosis was assessed. Linear regression analyses and Bland-Altman plots including Lin's concordance correlation coefficient were performed for correlation of FS R2* with non-FS R2*. Patients were grouped into 4 severity classes of iron overload (EASL based), and agreement was evaluated by contingency tables and the proportion of overall agreement. RESULTS: A total of 41.8% of patients showed hepatic iron overload; 67.9% had concomitant steatosis; and 58.2% revealed no iron overload of whom 60.3% had steatosis. The mean R2* value for all FS data was 102.86 1/s, for non-FS 108.16 1/s. Linear regression resulted in an R-squared value of 0.99 (p < 0.001); Bland-Altman plot showed a mean R2* difference of 5.26 1/s (SD 17.82). The concordance correlation coefficient was only slightly lower for patients with steatosis compared with non-steatosis (0.988 vs. 0.993). The overall agreement between FS and non-FS R2* measurements was 94.8% using either method to classify patients according to severity of iron storage. No correlation between R2* and proton density fat fraction was found for both methods. CONCLUSION: R2* relaxometry showed an excellent overall agreement between FS and non-FS acquisition. Both variants can therefore be used in daily routine. However, clinically relevant differences might result when switching between the two methods or during patient follow-up, when fat content changes over time. We therefore recommend choosing a method and keeping it straight in the context of follow-up examinations. KEY POINTS: • Both variants of R2* relaxometry (FS and non-FS) may be used in daily routine. • Clinically relevant differences might result when switching between the two methods or during patient follow-up, when fat content changes over time. • It seems advisable choosing one method and keeping it straight in the context of follow-up examinations.

Does gadoxetate disodium affect MRE measurements in the delayed hepatobiliary phase?

OBJECTIVES: To assess if the administration of gadoxetate disodium (Gd-EOB-DTPA) significantly affects hepatic magnetic resonance elastography (MRE) measurements in the delayed hepatobiliary phase (DHBP). METHODS: A total of 47 patients (15 females, 32 males; age range 23-78 years, mean 54.28 years) were assigned to standard hepatic magnetic resonance imaging (MRI) with application of Gd-EOB-DTPA and hepatic MRE. MRE was performed before injection of Gd-EOB-DTPA and after 40-50 min in the DHBP. Liver stiffness values were obtained before and after contrast media application and differences between pre- and post-Gd-EOB-DTPA values were evaluated using a Bland-Altman plot and the Mann-Whitney-Wilcoxon test. In addition, the data were compared with regard to the resulting fibrosis classification. RESULTS: Mean hepatic stiffness for pre-Gd-EOB-DTPA measurements was 4.01 kPa and post-Gd-EOB-DTPA measurements yielded 3.95 kPa. We found a highly significant individual correlation between pre- and post-Gd-EOB-DTPA stiffness values (Pearson correlation coefficient of r = 0.95 (p < 0.001) with no significant difference between the two measurements (p =0.49)). Bland-Altman plot did not show a systematic effect for the difference between pre- and post-stiffness measurements (mean difference: 0.06 kPa, SD 0.81). Regarding the classification of fibrosis stages, the overall agreement was 87.23% and the intraclass correlation coefficient was 96.4%, indicating excellent agreement. CONCLUSIONS: Administration of Gd-EOB-DTPA does not significantly influence MRE stiffness measurements of the liver in the DHBP. Therefore, MRE can be performed in the DHBP. KEY POINTS: • MRE of the liver can reliably be performed in the delayed hepatobiliary phase. • Gd-EOB-DTPA does not significantly influence MRE stiffness measurements of the liver. • MRE performed in the delayed hepatobiliary-phase is reasonable in patients with reduced liver function.

Impact of patatin-like phospholipase domain containing 3 rs738409 G/G genotype on hepatic decompensation and mortality in patients with portal hypertension.

BACKGROUND: The rs738409 C>G p.I148M variant in the patatin-like phospholipase domain containing 3 (PNPLA3)-gene promotes triglyceride accumulation in hepatocytes and hepatic stellate cell activation and has previously been linked to hepatic steatosis/liver fibrosis. AIM: To investigate its impact on hepatic decompensation and (liver-related) mortality in patients who had already developed portal hypertension. Moreover, we assessed its link with hepatic steatosis as evaluated by controlled attenuation parameter. METHODS: We performed a retrospective analysis in prospectively characterised patients with viral hepatitis/fatty liver disease-induced portal hypertension (hepatic venous pressure gradient [HVPG] ≥ 6 mm Hg) diagnosed at the Medical University of Vienna who underwent HVPG measurement (until 2013; n = 372; longitudinal study) or simultaneous HVPG and controlled attenuation parameter measurement (2014-2017; n = 153; cross-sectional study). RESULTS: While survival was similar between PNPLA3-C/C and -C/G patients, we observed substantially increased mortality in PNPLA3-G/G patients. PNPLA3-G/G had no impact on mortality in the subgroup of patients with viral hepatitis; however, we observed a strong independent association between PNPLA3-G/G and hepatic decompensation (adjusted subdistribution hazard ratio [aSHR]: 2.1, 95% confidence interval [95% CI]: 1.1-4; P = 0.024) as well as mortality (overall: aSHR: 2.2, 95% CI: 1.22-3.98; P = 0.009; liver-related: aSHR: 2.2, 95% CI: 1.08-4.46; P = 0.029) in patients with fatty liver disease. Interestingly, even in the subgroup of patients who had already progressed to clinically significant portal hypertension (HVPG ≥ 10 mm Hg), PNPLA3-G/G substantially increased mortality (aSHR: 2.33, 95% CI: 1.27-4.29; P = 0.006). PNPLA3-genotype had no influence on controlled attenuation parameter or the prevalence of values ≥248 dB/m. CONCLUSION: PNPLA3-G/G-genotype seems to double the risks of hepatic decompensation and (liver-related) mortality in patients with portal hypertension due to fatty liver disease. Further studies are warranted to investigate potential underlying pathophysiological mechanisms unrelated to hepatic steatosis.

A rare case of Epstein-Barr virus-associated hepatosplenic smooth muscle tumors after kidney transplantation.

A 27-year old caucasian male was diagnosed 2.7 years after kidney transplantation with Epstein-Barr virus (EBV)-associated smooth muscle tumors in liver and spleen. The reduction in immunosuppression and conversion from tacrolimus to sirolimus did not lead to a regression of the tumors. Additionally, the patient developed a cellular rejection of his renal allograft, which was successfully treated. A combined approach with stereotactic radiofrequency ablation (SRFA) and surgical resection was effective in the treatment of the tumors.

R2*-relaxometry of the pancreas in patients with human hemochromatosis protein associated hereditary hemochromatosis.

PURPOSE: To evaluate pancreatic iron in patients with human hemochromatosis protein associated hereditary hemochromatosis (HHC) using R2* relaxometry. MATERIALS AND METHODS: 81 patients (58 male, 23 female; median age 49.5, range 10-81 years) with HHC were retrospectively studied. All underwent 1.5T magnetic resonance imaging (MRI) of the abdomen. A fat-saturated multi-gradient echo sequence with 12 echoes (TR=200ms; TE-initial 0.99ms; Delta-TE 1.41ms; 12 echoes; flip-angle: 20°) was used for the R2* quantification of the liver and the pancreas. Parameter maps were analyzed using regions of interest (3 in the liver and 2 in the pancreas) and R2* values were correlated. RESULTS: 59/81 patients had a liver R2*≥70 1/s of which 10/59 patients had a pancreas R2*≥50 1/s. No patient presented with a liver R2*<70 1/s and pancreas R2*≥50 1/s. All patients with pancreas R2* values≥50 1/s had liver R2* values≥70 1/s. ROC analysis resulted in a threshold of 209.4 1/s for liver R2* values to identify HFE positive patients with pancreas R2* values≥50 1/s with a median specificity of 78.87% and a median sensitivity of 90%. CONCLUSION: In patients with HHC R2* relaxometry of the pancreas should be performed when liver iron overload is present and can be omitted in cases with no sign of hepatic iron.

R2* relaxometry for the quantification of hepatic iron overload: biopsy-based calibration and comparison with the literature.

PURPOSE: We compared the calibration of hepatic iron based on R2* relaxometry and liver biopsy with similar studies that have already been published to investigate the transferability of published calibration curves. MATERIALS AND METHODS: 17 patients with clinically suspected hepatic iron overload (HIO) were enrolled. All patients underwent liver biopsy and MRI of the liver using a multi-echo gradient echo sequence (TR = 200 ms; TE-initial 0.99 ms; Delta-TE 1.41 ms; 12 echos; flip-angle: 20 °). R2* parameter maps were analyzed using manually placed regions of interest and R2* values were correlated with liver iron concentration (LIC) obtained from liver biopsy. In addition, the results of our study were compared with 6 similar, already published studies. RESULTS: A linear relationship between R2* and LIC was found. Regression analysis yielded a correlation coefficient of 0.926, a slope of 0.024 (s mg/g) [95 % CI 0.013 - 0.024] and an intercept of 0.277 (mg/g) [95 % CI -0.328 - 2.49]. We found a significant correlation between the calibration curves obtained from our study in comparison to 3/6 similar studies. The other 3 studies used a different reference standard or sequence parameters which lead to a significant difference for slope, intercept or both in comparison to our data. CONCLUSION: Calibration curves from published studies that are based on a correlation of liver biopsy and R2* can be used for the estimation of liver iron concentration, although different scanning parameters and post-processing protocols were used. Low initial TEs might be a prerequisite for pooling data for liver iron quantification. KEY POINTS: • Calibration curves from different studies can be used for liver iron quantification• For that purpose calibration curves from published studies should be based on liver biopsy• Low initial TEs might be a prerequisite for pooling data for liver iron quantification.

Automated two-point dixon screening for the evaluation of hepatic steatosis and siderosis: comparison with R2-relaxometry and chemical shift-based sequences.

OBJECTIVES: To evaluate the automated two-point Dixon screening sequence for the detection and estimated quantification of hepatic iron and fat compared with standard sequences as a reference. METHODS: One hundred and two patients with suspected diffuse liver disease were included in this prospective study. The following MRI protocol was used: 3D-T1-weighted opposed- and in-phase gradient echo with two-point Dixon reconstruction and dual-ratio signal discrimination algorithm ("screening" sequence); fat-saturated, multi-gradient-echo sequence with 12 echoes; gradient-echo T1 FLASH opposed- and in-phase. Bland-Altman plots were generated and correlation coefficients were calculated to compare the sequences. RESULTS: The screening sequence diagnosed fat in 33, iron in 35 and a combination of both in 4 patients. Correlation between R2* values of the screening sequence and the standard relaxometry was excellent (r = 0.988). A slightly lower correlation (r = 0.978) was found between the fat fraction of the screening sequence and the standard sequence. Bland-Altman revealed systematically lower R2* values obtained from the screening sequence and higher fat fraction values obtained with the standard sequence with a rather high variability in agreement. CONCLUSIONS: The screening sequence is a promising method with fast diagnosis of the predominant liver disease. It is capable of estimating the amount of hepatic fat and iron comparable to standard methods. KEY POINTS: • MRI plays a major role in the clarification of diffuse liver disease. • The screening sequence was introduced for the assessment of diffuse liver disease. • It is a fast and automated algorithm for the evaluation of hepatic iron and fat. • It is capable of estimating the amount of hepatic fat and iron.

Serum prolactin in advanced chronic liver disease.

Hyperprolactinemia is a frequent endocrine disorder with well known harmful effects on the reproductive system and bone metabolism. Besides prolactinomas several drugs and disorders such as renal failure and hypothyroidism have been shown to cause hyperprolactinemia. Based on former studies, liver cirrhosis has also been suggested to cause hyperprolactinemia, while mechanisms have not been identified yet. In this study, we set out to investigate the prevalence and predictors of hyperprolactinemia in 178 patients with liver cirrhosis of different etio-logies. Eighteen out of 178 patients - 7 females and 11 males - displayed elevated serum pro-lactin levels. When patients were excluded who suffered from co-morbidities or took medication that are discussed to potentially interfere with prolactin metabolism, only 3 males displayed increased serum prolactin levels. Prolactin levels were similar in patients with liver cirrhosis of different etiologies. Our data suggest that hyperprolactinemia is not commonly found in patients with liver cirrhosis, but is mostly associated with intake of drugs or presence of comorbidites which are known to potentially cause hyperprolactinemia. We thus hypothesize that in contrast to former studies liver cirrhosis is not a common cause of hyperprolactinemia and that in the absence of co-morbidities or drugs that are known to potentially increase prolactin levels, marked hyperprolactinemia needs further investigation in patients with liver cirrhosis.

Evaluation of MR imaging with T1 and T2* mapping for the determination of hepatic iron overload.

OBJECTIVES: To evaluate MRI using T1 and T2* mapping sequences in patients with suspected hepatic iron overload (HIO). METHODS: Twenty-five consecutive patients with clinically suspected HIO were retrospectively studied. All underwent MRI and liver biopsy. For the quantification of liver T2* values we used a fat-saturated multi-echo gradient echo sequence with 12 echoes (TR = 200 ms, TE = 0.99 ms + n × 1.41 ms, flip angle 20°). T1 values were obtained using a fast T1 mapping sequence based on an inversion recovery snapshot FLASH sequence. Parameter maps were analysed using regions of interest. RESULTS: ROC analysis calculated cut-off points at 10.07 ms and 15.47 ms for T2* in the determination of HIO with accuracy 88 %/88 %, sensitivity 84 %/89.5 % and specificity 100 %/83 %. MRI correctly classified 20 patients (80 %). All patients with HIO only had decreased T1 and T2* relaxation times. There was a significant difference in T1 between patients with HIO only and patients with HIO and steatohepatitis (P = 0.018). CONCLUSIONS: MRI-based T2* relaxation diagnoses HIO very accurately, even at low iron concentrations. Important additional information may be obtained by the combination of T1 and T2* mapping. It is a rapid, non-invasive, accurate and reproducible technique for validating the evidence of even low hepatic iron concentrations. KEY POINTS: • Hepatic iron overload causes fibrosis, cirrhosis and increases hepatocellular carcinoma risk. • MRI detects iron because of the field heterogeneity generated by haemosiderin. • T2* relaxation is very accurate in diagnosing hepatic iron overload. • Additional information may be obtained by T1 and T2* mapping.

Hepcidin is correlated to soluble hemojuvelin but not to increased GDF15 during pregnancy.

Increased maternal and foetal iron requirements during pregnancy are compensated by an increase of intestinal iron absorption. Animal studies have shown that the expression of the main iron regulator hepcidin is significantly suppressed during pregnancy, but the factors associated with hepcidin suppression remain unknown. To investigate possible suppressors of hepcidin expression during pregnancy we determined serum concentrations of growth-differentiation factor-15 (GDF15), erythropoietin (EPO), soluble hemojuvelin (HJV) and hepcidin in 42 pregnant women at different time points of gestation and correlated them with serum iron and haematological parameters. Serum iron parameters and serum hepcidin concentration significantly decreased during pregnancy, whereas serum concentrations of GDF15, EPO and soluble HJV significantly increased. A negative correlation of hepcidin with EPO and soluble HJV but no correlation between hepcidin and GDF15 was found. Hepcidin and ferritin were positively correlated throughout the pregnancy. Our findings suggest that hepcidin expression is controlled by body iron stores where soluble HJV and EPO may act as suppressors of hepcidin.

Network "Rodent-borne pathogens" in Germany: longitudinal studies on the geographical distribution and prevalence of hantavirus infections.

Hantavirus infections are known in Germany since the 1980s. While the overall antibody prevalence against hantaviruses in the general human population was estimated to be about 1-2%, an average of 100-200 clinical cases are recorded annually. In the years 2005 and 2007 in particular, a large increase of the number of human hantavirus infections in Germany was observed. The most affected regions were located in the federal states of Baden-Wuerttemberg, Bavaria, North Rhine Westphalia, and Lower Saxony. In contrast to the well-documented situation in humans, the knowledge of the geographical distribution and frequency of hantavirus infections in their rodent reservoirs as well as any changes thereof was very limited. Hence, the network "Rodent-borne pathogens" was established in Germany allowing synergistic investigations of the rodent population dynamics, the prevalence and evolution of hantaviruses and other rodent-associated pathogens as well as their underlying mechanisms in order to understand their impact on the frequency of human infections. A monitoring of hantaviruses in rodents from endemic regions (Baden-Wuerttemberg, Bavaria, North Rhine Westphalia, Lower Saxony) and regions with a low number of human cases (Mecklenburg Western-Pomerania, Brandenburg, Saxony, Saxony-Anhalt) was initiated. Within outbreak regions, a high prevalence of Puumala virus (PUUV) was detected in bank voles. Initial longitudinal studies in North Rhine Westphalia (city of Cologne), Bavaria (Lower Bavaria), and Lower Saxony (rural region close to Osnabrück) demonstrated a continuing presence of PUUV in the bank vole populations. These longitudinal studies will allow conclusions about the evolution of hantaviruses and other rodent-borne pathogens and changes in their distribution, which can be used for a risk assessment of human infections. This may become very important in order to evaluate changes in the epidemiology of rodent-borne pathogens in the light of expected global climate changes in the future.

Distribution of DMT 1 within the human glandular system.

BACKGROUND & AIMS: DMT1 is a transmembrane protein which transports the divalent metal ions Fe2+, Zn2+, Cu2+ and Mn2+. Although DMT1 has been functionally linked to duodenal absorption and cellular utilisation of iron hardly anything is known about its distribution and potential role within the human glandular system. METHODS: Two polyclonal antibodies were raised to study the expression of DMT1 in tissues obtained from human corpus by the means of immunocytochemistry and Western blotting. RESULTS: All antibodies specifically detected a 60 kD protein band referring to human DMT1. Significant amounts of DMT1 expression were detected on the luminal site of organs, which are involved in excretion/re-absorption processes, such as salivary glands, pancreas, biliary tract and gallbladder. CONCLUSIONS: Our results suggest that DMT1 may be of pivotal importance for the regulation of metal ion homeostasis within organs involved in absorption and excretion of ions.

Interleukin-6 stimulates thrombopoiesis through thrombopoietin: role in inflammatory thrombocytosis.

Baseline platelet production is dependent on thrombopoietin (TPO). TPO is constitutively produced and primarily regulated by receptor-mediated uptake by platelets. Inflammatory thrombocytosis is thought to be related to increased interleukin-6 (IL-6) levels. To address whether IL-6 might act through TPO to increase platelet counts, TPO was neutralized in vivo in C57BL/10 mice treated with IL-6, and hepatic TPO mRNA expression and TPO plasma levels were studied. Transcriptional regulation of TPO mRNA was studied in the hepatoblastoma cell line HepG2. Furthermore, TPO plasma levels were determined in IL-6-treated cancer patients. It is shown that IL-6-induced thrombocytosis in C57BL/10 mice is accompanied by enhanced hepatic TPO mRNA expression and elevated TPO plasma levels. Administration of IL-6 to cancer patients results in a corresponding increase in TPO plasma levels. IL-6 enhances TPO mRNA transcription in HepG2 cells. IL-6-induced thrombocytosis can be abrogated by neutralization of TPO, suggesting that IL-6 induces thrombocytosis through TPO. A novel pathway of TPO regulation by the inflammatory mediator IL-6 is proposed, indicating that the number of platelets by themselves might not be the sole determinant of circulating TPO levels and thus of thrombopoiesis. This regulatory pathway might be of relevance for the understanding of reactive thrombocytosis.

Expression of the duodenal iron transporters divalent-metal transporter 1 and ferroportin 1 in iron deficiency and iron overload.

BACKGROUND & AIMS: Imbalances of iron homeostasis are accompanied by alterations of intestinal iron absorption. The identification of divalent-metal transporter 1 (DMT1) and ferroportin 1 (FP1) has improved our understanding of transmembrane iron trafficking. To gain insight into the regulatory properties of these transporters in the duodenum, we studied their expression in patients with hereditary hemochromatosis (HFE-associated and non-HFE-associated), secondary iron overload, and iron deficiency. METHODS: DMT1, FP1 messenger RNA (mRNA), and protein expression were analyzed in duodenal biopsy specimens from patients by means of TaqMan real-time polymerase chain reaction, Western blotting technique, and immunohistochemistry. RESULTS: DMT1 and FP1 mRNA levels are positively correlated with each other in all patient groups (P < 0.001). Moreover, DMT1 and FP1 mRNA levels were significantly increased in patients with iron deficiency, HFE and non-HFE hemochromatosis, whereas they were unchanged in patients with secondary iron overload. Alterations in DMT1 and FP1 mRNA levels were paralleled by comparable changes in the duodenal expression of these proteins. In patients with normal iron status or iron deficiency, significant negative correlations between DMT1, FP1 mRNA, and serum iron parameters were found, which were absent in subjects with primary hemochromatosis. CONCLUSIONS: DMT1 and FP1 are centrally involved in iron uptake/transfer in the duodenum and in the adaptive changes of iron homeostasis to iron deficiency and overload.

Duodenal metal-transporter (DMT-1, NRAMP-2) expression in patients with hereditary haemochromatosis.

BACKGROUND: Although the gene for hereditary haemochromatosis has been cloned, the mechanism by which iron uptake is inappropriately increased in this disorder is unclear. Iron absorption is regulated by the duodenal metal transporter, DMT-1, also called NRAMP-2. We investigated the expression of NRAMP-2 in patients with hereditary haemochromatosis. METHODS: Duodenal biopsy samples were taken from 20 patients with haemochromatosis homozygous for the C282Y mutation and from ten controls. NRAMP-2 expression was assessed by northern blotting and competitive PCR. NRAMP-2 mRNA was sequenced in seven patients and two controls. FINDINGS: Duodenal NRAMP-2 mRNA concentrations were increased in patients as estimated by Northern blotting. Accordingly, competitive PCR showed significantly higher NRAMP-2 cDNA concentrations in patients than in controls (mean 3.43 [SD 0.61] vs 1.11 [0.74] log ng competitor x 10(4); p<0.001). No mutations were found within the NRAMP-2 mRNA. Duodenal NRAMP-2 mRNA expression was correlated with serum ferritin in controls (r=-0.94, p=0.001) but not in patients (r=-0.18, p=0.8). INTERPRETATION: Increased NRAMP-2 mRNA expression in duodenal mucosa of patients with hereditary haemochromatosis may promote duodenal iron uptake and lead to iron overload.

Modulation of neopterin formation and tryptophan degradation by Th1- and Th2-derived cytokines in human monocytic cells.

In order to examine the regulatory effects of major Th1-derived cytokines, such as IL-12, and Th2 cytokines, IL-4 and IL-10, on the formation of neopterin and degradation of tryptophan, two metabolic pathways induced by interferon-gamma (IFN-gamma) in human monocytes/macrophages, we investigated the human monocytic cell line THP-1, primary human macrophages, and peripheral blood mononuclear cells (PBMC). Neopterin formation and tryptophan degradation were induced similarly by IFN-gamma in all three cell types investigated, but the effects of interleukins were different between THP-1, primary macrophages and PBMC. In PBMC, but not in THP-1 cells and primary macrophages, IL-12 was found to be additive to the effects of IFN-gamma to superinduce neopterin formation and tryptophan degradation. IL-4 and IL-10 reduced the effects of IFN-gamma on monocytic cells, and both cytokines were additively antagonistic to IFN-gamma in PBMC and THP-1 cells. Finally, on preincubation, but not on addition of IL-12, the effects of IL-4 and IL-10 on PBMC could be abrogated, whereas no such effect was seen in THP-1 cells. The results show that IL-12 up-regulates neopterin formation and tryptophan degradation by inducing additional IFN-gamma production by Th1 cells, while a direct effect of IL-12 on monocytes/macrophages appears to be absent. Similarly, IL-4 and IL-10 inhibit neopterin production and tryptophan degradation in PBMC by down-regulating Th1-type cytokine production and possibly also via direct deactivation of IFN-gamma effects towards monocytes/macrophages. The results clearly show how Th1 cell-mediated immunity may be up- or down-regulated by endogenous cytokine production.