Mycophenolate mofetil--a new treatment for autoimmune hepatitis?

Long-term outcome of patients with difficult-to-treat autoimmune hepatitis receiving mycophenolate mofetil

BACKGROUND

Most patients with autoimmune hepatitis (AIH) respond to a combination of prednisolone and azathioprine. For patients who are intolerant or refractory to azathioprine, proposed alternative therapies are based on scarce data, limited to transplant centres and with short-term follow-up periods.

OBJECTIVE

To evaluate the long-term efficacy and safety of MMF as a second-line therapy in patients with AIH managed at a tertiary non-transplant centre.

METHODS

Retrospective analysis of a prospectively collated database identified AIH patients who received MMF from 2006 to 2015. Clinical, biochemical and immunological parameters were assessed at 3-, 6- and 12-months, and at last follow-up. Biochemical response (BR) was defined as improvement of transaminases, complete remission (CR) as normalisation of transaminases and IgG, while others were considered non-responders (NR).

RESULTS

Eighteen out of 151 (12%) AIH patients received MMF. Nine received MMF due to azathioprine-intolerance (group 1), while nine due to refractory disease (group 2). In group 1, CR and BR was achieved in six (67%) and two (22%) patients respectively. In group 2, CR and BR was achieved in one (11%) and five (56%) patients respectively. Adverse events occurred in eight patients (44%), with one patient requiring drug discontinuation. After a medium follow-up of 78 (31-116) months, there was a significant decrease in transaminase levels, mirrored by decrease in prednisolone dose from 25 to 6.25 mg/day (P<0.05).

CONCLUSION

Long-term therapy with MMF is safe and effective in AIH patients requiring second-line therapies, and these patients can be effectively managed at tertiary non-liver transplant centres.

Tacrolimus and mycophenolate mofetil as second-line treatment in autoimmune hepatitis: Is the evidence of sufficient quality to develop recommendations?

BACKGROUND

The standard management of autoimmune hepatitis (AIH) is based on corticosteroids, alone or in combination with azathioprine. Second-line treatments are needed for patients who have refractory disease. However, high-quality data on the alternative management of AIH are scarce.

AIM

To evaluate the efficacy and safety of tacrolimus and mycophenolate mofetil (MMF) and the quality of evidence by using the Grading of Recommendations Assessment, Development and Evaluation approach (GRADE).

METHODS

A systematic review and meta-analysis of the available data were performed. We calculated pooled event rates for three outcome measures: Biochemical remission, adverse events, and mortality, with their corresponding 95% confidence intervals (CI).

RESULTS

The pooled biochemical remission rate was 68.9% (95%CI: 60.4-76.2) for tacrolimus, and 59.6% (95%CI: 54.8-64.2) for MMF, and rates of adverse events were 25.5% (95%CI: 12.4-45.3) for tacrolimus and 24.1% (95%CI: 15.4-35.7) for MMF. The pooled mortality rate was estimated at 11.5% (95%CI: 7.1-18.1) for tacrolimus and 9.01% (95%CI: 6.2-12.8) for MMF. Pooled biochemical remission rates for tacrolimus and MMF in patients with intolerance to standard therapy were 56.6% (CI: 43.4-56.6) vs 73.5% (CI: 58.1-84.7), and among non-responders were 59.1% (CI: 48.7-68.8) vs 40.8% (CI: 32.3-50.0), respectively. Moreover, the overall quality assessments using GRADE proved to be very low for all our outcomes in both treatment groups.

CONCLUSION

Tacrolimus and MMF are in practice considered effective for patients with AIH who are non-responders or intolerant to first-line treatment, but we found no high-quality evidence to support this statement.

Mycophenolate mofetil as a rescue therapy for autoimmune hepatitis patients who are not responsive to standard therapy

Autoimmune hepatitis (AIH) is a chronic liver disease of unknown etiology that is responsive to steroid and azathioprine treatment in more than 80% of patients after 3 years of treatment. There are few alternative treatment options for individuals with AIH who are unresponsive to steroids and azathioprine, and research on this is limited to open-label studies of a variety of immunosuppressive agents that involve only small numbers of patients. Mycophenolate mofetil is one of the most frequently used alternative agents for the treatment of AIH patients not responsive to standard therapy. In this article, we review and summarize currently available data regarding the use of mycophenolate mofetil as an alternative treatment option for patients with AIH.

Inosine 5'-monophosphate dehydrogenase inhibition by mycophenolic acid impairs maturation and function of dendritic cells

BACKGROUND

The mechanism of action of mycophenolic acid (MPA) has been described as a blockade of inosine 5'-monophosphate dehydrogenase (IMPDH) and is thought to selectively influence T- and B-lymphocytes due to their strong dependency on guanine nucleotides synthesized via the de novo purine synthesis pathway. Recent evidence suggests MPA to affect antigen-presenting cells.

METHODS

Using CD14+ derived human dendritic cells (DC) we have investigated the effects of MPA on differentiation, maturation and function and studied intracellular nucleotide content and IMPDH activity.

RESULTS

GTP content and IMPDH activities of DC were strongly and dose-dependently decreased when MPA was present during the entire culture period or was added after the fifth (immature DC) or the seventh (mature DC) day of culture. Concurrent to low GTP levels, a dose-dependent reduction in the expression of CD80, CD86, CD40, CD54 and CD83 was seen which was accompanied by a decreased capacity of DC to stimulate T-cells. Our data for the first time shows a direct effect of MPA on the maturation and function of human CD14+ derived DC, indicates a role of IMPDH and a dependency on the de novo purine synthesis pathway.

Autoimmune hepatitis in children

AIH, ASC, and de novo AIH after liver transplantation are childhood liver diseases of an autoimmune nature. The mode of presentation of AIH in childhood is variable, and the disease should be suspected and excluded in all children presenting with symptoms and signs of prolonged or severe acute liver disease. Although corticosteroids are effective in all types of childhood AIH, patients with LKM1 have a higher frequency of acute hepatic failure and relapse after corticosteroid withdrawal than do patients with ANA/SMA. ASC occurs commonly in the absence of inflammatory bowel disease, requires cholangiography for diagnosis, and improves during corticosteroid therapy. The development of AIH de novo in children who undergo liver transplantation for nonautoimmune liver disease may reflect interference with the maturation of T cells by immunosuppressive drugs.

Autoimmune liver disease

Autoimmune liver disorders are inflammatory liver diseases characterised histologically by a dense mononuclear cell infiltrate in the portal tract and serologically by the presence of non-organ and liver specific autoantibodies and increased levels of immunoglobulin G (IgG), in the absence of a known etiology. They usually respond to immunosuppressive treatment, which should be instituted as soon as diagnosis is made. The onset is variable and often mimics acute hepatitis. The previously accepted requirement of six month duration of symptoms before a diagnosis of autoimmune disease could be made has been abandoned.

Autoimmune hepatitis

Autoimmune liver disease encompasses several disorders (Table 1). Autoimmune hepatitis (AIH) affects mainly women and is characterized histologically by a portal tract mononuclear cell infiltrate disrupting the limiting plate and invading the parenchyma ("interface hepatitis") and serologically by the presence of autoantibodies and increased levels of immunoglobulin G (IgG), in the absence of a known cause. AIH responds to immunosuppressive treatment. It can present insidiously or as an acute hepatitis. The previously accepted requirement of 6-month duration of symptoms before diagnosis can be made has been abandoned and treatment should be instituted as soon as the disease is diagnosed. In this review, we concentrate on those reports that add to our knowledge in terms of pathogenesis, differential diagnosis, treatment, and clinical course. Special attention is given to overlap syndromes.