Stefano Marchini

Hyperhomocysteinaemia in chronic liver diseases: role of disease stage, vitamin status and methylenetetrahydrofolate reductase genetics

Abstract: Background/Aims: The liver plays a key role in sulphur aminoacid metabolism hence, homocysteine metabolism may be impaired in chronic liver diseases. The aim of this study was to investigate, in patients affected by chronic liver diseases, (1) the prevalence of hyperhomocysteinaemia and (2) the role of its determinants such as the stage and the aetiology of disease, vitamin status, genetic documented alterations (methylenetetrahydrofolate reductase deficiency) and presence/absence of documented malignant evolution (hepatocellular carcinoma).

Antioxidant liposoluble vitamins and carotenoids in chronic hepatitis.

Background: It is known that antioxidant liposoluble vitamins and carotenoids are reduced in liver cirrhosis, but little is known about chronic viral hepatitis, where oxidative damage has to be taken into account. Methods: Fifty-five patients with chronic hepatitis, mainly C virus-related, were matched with 16 patients with biliary stones and 20 healthy controls. Plasma and liver analyses were carried out using a well-tried HPLC technique that affords an accurate quantification of retinol, tocopherol, alpha- and beta-carotene, cryptoxanthin, and lycopene. Results: Plasma concentration of retinol, tocopherol, beta-carotene, and lycopene was significantly decreased in both patient groups, particularly in those with chronic hepatitis. In contrast, liver concentration of both esterified and free retinol, tocopherol, and some carotenoids was better preserved in the hepatitis group than in the cholelithiasis group. A strict correspondence between aminotransferases and the amount of liver-stored retinol was documented. Conclusions: Plasma vitamin and carotenoid depletion co-existing with preserved liver storage may indicate a functional defect in liver pool mobilization or even a real depletion of the antioxidant defenses, which play a key role in averting cellular damage. The implications for nutrition and therapy need to be taken into account.

Hyperhomocysteinaemia in HIV-infected patients: determinants of variability and correlations with predictors of cardiovascular disease.

We evaluated hyperhomocysteinaemia (HHcy) in a cohort of HIV‐infected patients in order to assess its relation to cardiovascular risk (CVR) and identify determinants of HHcy variability.

Clinical, biochemical and genetic characteristics of Variegate Porphyria in Italy.

Variegate Porphyria (VP) is an autosomal dominant disorder found worldwide but is rare in Italy. In this study we provide an overview of clinical, biochemical and genetic background of 33 Italian VP patients diagnosed in the last fifteen years. About 70% of patients had experienced clinical symptoms: 43.4% had photosensivity, 8.7% acute attacks and 47.8% both. Among the 33 patients, 14 different mutations were identified. Of these only 6 defects have been previously described in other countries and 8 are unique having been identified for the first time in Italy. Two of these, the c.851G>T and the c.1013C>G, were found in two and four unrelated families respectively. No mutation has been found in homozygosis and no significant correlation has been observed between specific clinical and biochemical manifestations and the type of mutation. In contrast, normal faecal protoporphyrin excretion was high predictive of silent phenotype. Normal urinary excretion of PBG and ALA, predicted absence of neurovisceral symptoms. This paper represents the first compilation of data on genotype-phenotype relation in Italian patients with VP.

Hyperhomocysteinemia and MTHFR C677T polymorphism in patients with portal vein thrombosis complicating liver cirrhosis

BACKGROUND Portal vein thrombosis (PVT) is serious complication of liver cirrhosis (LC), especially in the presence of hepatocellular carcinoma (HCC). The liver plays a key role in homocysteine (Hcy) metabolism: mild hyperhomocysteinemia (HHcy) has been described in LC. HHcy is a risk factor for deep vein thrombosis. Methylen-tetrahydrofolate-reductase (MTHFR) C677T polymorphism is the commonest determinant of mild HHcy and has been involved also in cancer development. AIM To investigate a possible relation between HHcy, MTHFR status, HCC and PVT in patients affected by LC. MATERIALS AND METHODS 100 patients affected by LC, 38 with (PVT group, 24 with HCC) and 62 without PVT (LC group, 14 with HCC) sex-, age-, liver disease stage and etiology-matched were assessed for thrombophilia, smoking status, plasma Hcy, MTHFRC677T polymorphism and homocysteine-related vitamin status. RESULTS A higher prevalence of HCC, HHcy and MTHFR TT status was observed in PVT group. No significant difference in vitamin status was observed between groups. Patients with HCC showed significantly higher plasma Hcy and higher prevalence of HHcy than patients without HCC. They had also higher prevalence of MTHFR TT status. In patients with TT status (n=11) and HCC, 10 had HHcy e 9 had PVT. CONCLUSIONS Mild HHcy is associated to LC may have a role in PVT development and assessment of plasma Hcy may be suggested in patients with LC (especially if complicated by HCC). Association between HCC and MTHFR TT status is intriguing, due the postulated role for this polymorphism in cancer: it may represent a possible link between HCC and PVT.

Role of Multidrug-Resistance Protein 2 in coproporphyrin transport: results from experimental studies in bile fistula rat models

Coproporphyrin (CP) is one of the main by-products of heme biosynthesis and its abnormal accumulation is associated with different forms of porphyria. Indirect data obtained from animal and human models have suggested a possible role for Multidrug Resistance-associated Protein 2 (MRP2) and other MRPs in hepatocyte excretion of CP. Using normal, MRP2-deficient and a cholestatic rat model, we have assessed the role of MRPs in CP disposition. MRP levels were assayed using immunofluorescence. Biliary and urinary excretion patterns of CP and conjugate bilirubin were measured during equimolar infusions of CP isomers with and without phenoldibromopthalein sulfonate (BSP), a well-known MRP2 substrate. Our results suggest a role for the MRP system as a possible regulator of CP traffic and accumulation in normal and pathological conditions. Alteration in this systems (as observed in cholestatic disease) may play an important role in triggering clinical expression of porphyria in individuals with underlying mutations leading to porphyrin accumulation and may help explain the phenotypic heterogeneity in patients affected by different forms of porphyrias.

Acute Intermittent Porphyria in a Child with Severe Neuropathy

Clinical presentation of acute intermittent porphyria before puberty is unusual. We diagnosed the non-erythroid variant form of this disease in a male child, who first presented, at the age of 6 years, with unexplained neurological symptoms and behavioural abnormalities. We also report the successful treatment, and the long-term clinical management.