Contribution of zinc deficiency to insulin resistance in patients with primary biliary cirrhosis

The relationship between metabolic abnormalities of trace elements and insulin resistance has been established. Recent studies have revealed that insulin resistance is associated with autoimmune responses. The purpose of this study was to examine the correlation between zinc or copper metabolism and insulin resistance in patients with primary biliary cirrhosis (PBC). Sixteen patients with PBC were divided into two groups: early and advanced stage disease. The overall value of the homeostasis model assessment of insulin resistance (HOMA-IR) in patients with advanced stage PBC was significantly higher than that in patients with early stage PBC, although the mean value in advanced stage PBC was significantly lower than that in hepatitis C virus (HCV)-related liver cirrhosis. There was an inverse correlation between serum zinc concentrations and HOMA-IR values in patients with PBC, while we found no correlation between serum copper levels and HOMA-IR values. HOMA-IR values were inversely associated with peripheral platelet counts, indicating the relationship between insulin resistance and hepatic fibrosis. These results suggest that zinc deficiency plays important roles of insulin resistance and subsequent hepatic fibrosis in patients with PBC, although insulin resistance in advanced stage PBC was significantly milder than that in HCV-related liver cirrhosis.

Clinical characteristics of patients with autoimmune hepatitis seropositive for anticentromere antibody

AIM

Recent studies have revealed that primary biliary cirrhosis patients with anticentromere antibody (ACA) commonly develop portal hypertension. However, the clinical characteristics of autoimmune hepatitis (AIH) remain uncertain. We investigated the clinical features of patients with AIH seropositive for ACA (ACA-AIH), comparing them with those of patients with AIH seropositive for other immunofluorescent patterns of antinuclear antibodies (ANA) (other-AIH).

METHODS

AIH was diagnosed on the basis of the scoring system proposed by the International Autoimmune Hepatitis Group. Seropositivity for ACA was determined by a discrete speckled pattern on HEp-2 cells by an immunofluorescent technique. The severity of histological grading and staging was evaluated by the histological activity index (HAI) score.

RESULTS

Eight (17%) of 47 patients with AIH had ACA. No significant differences in age, sex, onset pattern of the disease, progression to hepatic failure and relapse rate were present between the ACA-AIH and other-AIH groups. The frequency of concurrent autoimmune diseases in ACA-AIH was significantly higher than that in other-AIH (75% vs 36%, P = 0.0406). Biochemical analysis revealed a significantly lower mean immunoglobulin G (IgG) level than that in other-AIH (2176 +/- 641 vs 3013 +/- 923 mg/dL, P = 0.0150). However, there were no differences in serum alanine aminotransferase levels, titers of ANA, HAI scores or the positive rate of human leukocyte antigen (HLA)-DR4 between the groups.

CONCLUSION

These results suggest that the emergence of ACA is not a distinct entity of AIH, despite its clinical characteristics of a significantly higher frequency of concurrent autoimmune diseases and lower serum IgG levels.

Efficacy of zinc administration in patients with hepatitis C virus-related chronic liver disease

OBJECTIVE

Zinc supplementation has been shown to contribute to inhibition of liver fibrosis and improvement in hepatic encephalopathy. However, little is known about the anti-inflammatory effect of zinc on hepatitis C virus (HCV)-related chronic liver disease (CLD). We therefore examined the effects of zinc administration on inflammatory activity and fibrosis in the liver of patients with HCV-related CLD.

MATERIAL AND METHODS

Polaprezinc, a complex of zinc and l-carnosine, was administrated at 225 mg/day for 6 months to 14 patients with HCV-related CLD, in addition to their ongoing prescriptions. Peripheral blood cell counts, liver-related biochemical parameters, serological markers for liver fibrosis, HCV-RNA loads, and serum levels of zinc and ferritin were evaluated before and after zinc administration.

RESULTS

Serum zinc concentrations were positively correlated with hepatic reserve before zinc supplementation. A significant increase in serum zinc level was observed after zinc supplementation (64+/-15 versus 78+/-26 mg/dl, p=0.0156). Treatment with polaprezinc significantly decreased serum aminotransferase levels (aspartate aminotransferase (AST): 92+/-33 versus 63+/-23 IU/l, p=0.0004; alanine aminotransferase (ALT): 106+/-43 versus 65+/-32 IU/l, p=0.0002), whereas alkaline phosphatase levels were significantly increased (305+/-117 versus 337+/-118 U/l, p=0.0020). Serum ferritin levels were significantly decreased by treatment with polaprezinc (158+/-141 versus 101+/-80 ng/ml, p=0.0117). The reduction rate of ALT levels by polaprezinc was positively correlated with that of ferritin (r(2)=0.536, p=0.0389). There was a tendency toward a decrease in serum type IV collagen 7S levels after treatment with polaprezinc. However, administration of polaprezinc did not affect peripheral blood cell counts, other liver function tests, or HCV-RNA loads.

CONCLUSIONS

These findings suggest that polaprezinc exerts an anti-inflammatory effect on the liver in patients with HCV-related CLD by reducing iron overload.