Effects of penicillamine on serum immunoglobulins and immune complex-reactive material in primary biliary cirrhosis

Targeting FcRn for immunomodulation: Benefits, risks, and practical considerations

The neonatal fragment crystallizable (Fc) receptor (FcRn) functions as a recycling mechanism to prevent degradation and extend the half-life of IgG and albumin in the circulation. Several FcRn inhibitors selectively targeting IgG recycling are now moving rapidly toward clinical practice in neurology and hematology. These molecules accelerate the destruction of IgG, reducing pathogenic IgG and IgG immune complexes, with no anticipated effects on IgA, IgM, IgE, complement, plasma cells, B cells, or other cells of the innate or adaptive immune systems. FcRn inhibitors have potential for future use in a much wider variety of antibody-mediated autoimmune diseases. Given the imminent clinical use, potential for broader utility, and novel mechanism of action of FcRn inhibitors, here we review data from 4 main sources: (a) currently available activity, safety, and mechanism-of-action data from clinical trials of FcRn inhibitors; (b) other procedures and treatments that also remove IgG (plasma donation, plasma exchange, immunoadsorption); (c) diseases resulting in loss of IgG; and (d) primary immunodeficiencies with potential mechanistic similarities to those induced by FcRn inhibitors. These data have been evaluated to provide practical considerations for the assessment, monitoring, and reduction of any potential infection risk associated with FcRn inhibition, in addition to highlighting areas for future research.

D-penicillamine for primary biliary cirrhosis

BACKGROUND

D-penicillamine is used for patients with primary biliary cirrhosis due to its hepatic copper decreasing and immunomodulatory potentials. The results from randomised clinical trials have been inconsistent.

OBJECTIVES

To systematically review the beneficial and harmful effects of D-penicillamine for patients with primary biliary cirrhosis.

SEARCH STRATEGY

We identified trials through electronic searches of The Cochrane Hepato-Biliary Group Controlled Trials Register (September 2003), The Cochrane Central Register of Controlled Trials on The Cochrane Library (Issue 3, 2003), MEDLINE (January 1966 to September 2003), EMBASE (January 1980 to September 2003), The Chinese Biomedical CD Database (January 1979 to August 2003), and LILACS (1982 to 2003); through manual searches of bibliographies; and by contacting authors of the trials and pharmaceutical companies.

SELECTION CRITERIA

We included randomised clinical trials comparing D-penicillamine with placebo/no intervention or other control intervention irrespective of language, year of publication, and publication status.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed the methodological quality of the trials and extracted data, validated by a third reviewer. The primary outcomes were 1) mortality and 2) a combination of those who died or underwent liver transplantation. We analysed dichotomous outcomes as relative risk (RR) with 95% confidence interval (CI) by a fixed effect model and a random effects model. We investigated sources of heterogeneity by subgroup analyses and tested the robustness of our findings by sensitivity analyses.

MAIN RESULTS

We included seven trials randomising 706 patients with primary biliary cirrhosis. D-penicillamine compared with placebo/no intervention tended to increase mortality (RR 1.34, 95% CI 1.09 to 1.64, fixed; RR 1.46, 95% CI 0.85 to 2.50, random). However, there was substantial heterogeneity. No significant differences were detected regarding the risks of mortality or liver transplantation, pruritus, liver complications, progression of liver histological stage, or the levels of liver biochemical variables (except alanine aminotransferase). D-penicillamine versus placebo/no intervention significantly increased the risk of adverse events (RR 3.11, 95% CI 2.33 to 4.16, fixed; RR 4.18, 95% CI 1.38 to 12.69, random).

REVIEWERS' CONCLUSIONS

D-penicillamine did not appear to reduce the risk of mortality, but significantly increased the occurrences of adverse events in patients with primary biliary cirrhosis. We do not support the use of D-penicillamine for patients with primary biliary cirrhosis.

Evaluation of colchicine therapy in primary biliary cirrhosis

We have conducted a double-blind controlled trial of colchicine in patients with primary biliary cirrhosis. Fifty-seven patients with biopsy-proven primary biliary cirrhosis were randomized to receive either 0.6 mg of colchicine twice daily or an identically appearing placebo. Patients underwent clinical and laboratory evaluation every 3 mo and liver biopsy annually. Differences in mean alkaline phosphatase and alanine aminotransferase values between the colchicine and placebo recipients were statistically significant at 4 yr. Differences in mean bilirubin and immunoglobulin M values, although lower in the colchicine group, did not reach statistical significance. In colchicine-treated patients, mean alkaline phosphatase values fell significantly compared with controls, from 281 to 112 IU/L (p less than 0.01). Similarly, mean alanine aminotransferase values fell significantly compared with controls, from 129 to 86 IU/L (p less than 0.05). Bilirubin values remained stable in drug-treated patients, even in those patients with initially elevated bilirubin values, whereas they nearly doubled in subjects receiving placebo. Although biochemical parameters of disease activity improved or stabilized in colchicine-treated subjects, no difference in histologic progression was detected between the two treatment groups. We conclude that colchicine is of clinical benefit to patients with primary biliary cirrhosis as judged by improvement in alkaline phosphatase and alanine aminotransferase activities as well as a tendency for stabilization of bilirubin values.

Review: the treatment of primary biliary cirrhosis

Considerable improvement in quality of life can be achieved by treating the complications of primary biliary cirrhosis. However, once fibrosis, cirrhosis, portal hypertension and hyperbilirubinaemia occur, it is unlikely that 'medical' treatment will cure the disorder. Trials of medical therapy should aim to delay or halt the progression of the early phase of the disease and clinicians should refer patients to centres conducting clinical trials. If the disease progresses, and the quality of life is seriously impaired, liver transplantation offers the realistic chance of a new life.