Controlled trial of a thymic hormone extract (Thymostimulin) in 'autoimmune' chronic active hepatitis

Systematic review of response criteria and endpoints in autoimmune hepatitis by the International Autoimmune Hepatitis Group

BACKGROUND & AIMS

Autoimmune hepatitis (AIH) has been well characterised and codified through the development of diagnostic criteria. These criteria have been adapted and simplified and are widely used in clinical practice. However, there is a need to update and precisely define the criteria for both treatment response and treatment.

METHODS

A systematic review was performed and a modified Delphi consensus process was used to identify and redefine the response criteria in autoimmune hepatitis.

RESULTS

The consensus process initiated by the International Autoimmune Hepatitis Group proposes that the term 'complete biochemical response' defined as 'normalization of serum transaminases and IgG below the upper limit of normal' be adopted to include a time point at 6 months after initiation of treatment. An insufficient response by 6 months was a failure to meet the above definition. Non-response was defined as '<50% decrease of serum transaminases within 4 weeks after initiation of treatment'. Remission is defined as liver histology with a Hepatitis Activity Index <4/18. Intolerance to treatment was agreed to stand for 'any adverse event possibly related to treatment leading to potential drug discontinuation'.

CONCLUSIONS

These definitions provide a simple and reproducible framework to define treatment response and non-response, irrespective of the therapeutic intervention. A consensus on endpoints is urgently required to set a global standard for the reporting of study results and to enable inter-study comparisons. Future prospective database studies are needed to validate these endpoints.

LAY SUMMARY

Consensus among international experts on response criteria and endpoints in autoimmune hepatitis is lacking. A consensus on endpoints is urgently required to set a global standard for the reporting of study results and to enable the comparison of results between clinical trials. Therefore, the International Autoimmune Hepatitis Group (IAIHG) herein presents a statement on 5 agreed response criteria and endpoints: complete biochemical response, insufficient response, non-response, remission, and intolerance to treatment, which can be used to guide future reporting.

Comparative efficacy and tolerability of treatments for adult autoimmune hepatitis: A systematic review and network meta-analysis

The most suitable treatment regimen for autoimmune hepatitis (AIH) in adults remains unknown and requires further investigation. The current study therefore aimed to integrate evidence to provide hierarchies of the comparative efficacies of treatments measured by clinical and biochemical remission. A Bayesian-framework network meta-analysis of randomized controlled trials (RCTs) was preformed to compare eight treatments for AIH. Eligible RCTs were identified by searching Embase, Pubmed and the Cochrane Library for publications between 1966 and April 2017. All outcomes were independently extracted from the included studies by two authors. A total of six RCTs were subsequently included in the current study. The network of comparisons on remission indicated that patients treated with prednisone (pred) experienced significantly increased rates of remission compared with those treated with azathioprine [AZA; odds ratio (OR), 0.21; 95% confidence interval (CI), 0.06-0.71] and budesonide (bude) + AZA significantly increased remission compared with placebo treatment (OR, 36.66; 95% CI, 1.40-962.49) or AZA (OR, 10.30; 95% CI, 1.50-70.70). Based on the cumulative ranking probabilities, bude + AZA (89.4) was ranked first, pred (69.1) was ranked second, pred + AZA (63.2) was ranked third and placebo (7.8) treatment was ranked last. Bude + AZA may be the most appropriate candidate for the treatment of non-cirrhotic patients. However, bude + AZA as frontline therapy for AIH requires more large-scale studies with a longer duration of follow-up histology and a focus on dose-response. Additionally, development of other prospective treatments, which may be used as alternative therapy or first line therapy, and their subsequent evaluation in clinical RCTs is required.

Treatment options for autoimmune hepatitis: a systematic review of randomized controlled trials

BACKGROUND & AIMS

Predniso(lo)ne with or without azathioprine is considered the mainstay in the treatment of autoimmune hepatitis (AIH), but many therapeutic options are available. The primary objective of this review was to explore the published literature on the optimal induction and subsequent maintenance therapy for AIH.

METHODS

We performed a systematic search on electronic databases MEDLINE (1950-07.2009), Web of Science, Cochrane, and the website www.clinicaltrials.gov. Randomized controlled trials (RCTs) on apparent beneficial treatment regimens as induction or maintenance treatment in AIH were included. Pediatric studies were excluded. We calculated relative risks (RR) for comparison of treatment options on the primary outcome measure, which was defined as clinical, biochemical and histological remission.

RESULTS

Eleven RCTs were included, of which 7 studies evaluated the induction therapy in AIH patients: 3 treatment naive (n=253), 2 relapse (n=53), 2 combination of naive and relapse (n=110). The remaining 4 studies (n=162) assessed maintenance therapy. All but one maintenance study (thymostimulin versus no therapy) studied predniso(lo)ne (PRED), azathioprine (AZA) or combination PRED+AZA. We found no differences in primary outcome between induction therapy with PRED and PRED+AZA in treatment naive patients (RR=0.98; 95% CI 0.65-1.47). AZA monotherapy as induction was considered as not viable because of a high mortality rate (30%). This was similar in AIH patients who relapsed: RR for PRED versus PRED+AZA for inducing remission was not different: 0.71 (95% CI 0.37-1.39). PRED+AZA maintained remission more often than PRED (RR=1.40; 95% CI 1.13-1.73). Also AZA maintained a higher remission rate than PRED (RR=1.35; 95% CI 1.07-1.70). Maintenance of remission was not different between PRED+AZA and AZA (RR=1.06; 95% CI 0.94-1.20).

CONCLUSIONS

Based on available RCTs, PRED monotherapy and PRED+AZA combination therapy are both viable induction therapies for AIH treatment naives and relapsers, while for maintenance therapy PRED+AZA and AZA therapy are superior to PRED monotherapy.

Review article: immunopathogenetic and therapeutic aspects of autoimmune hepatitis

Autoimmune hepatitis is a chronic, progressive liver disease that responds well to immunosuppressive therapy, but has a poor prognosis if untreated. Possible triggering factors include viruses, other autoimmune disorders and drugs. The molecular mechanisms contributing to the pathogenesis include: reactions of autoantibodies against their corresponding autoantigens; aberrant expression of histocompatibility antigen class I and II molecules, cell adhesion molecules and cytokines; increased oxidative stress; and the occurrence of angiogenesis. The prevalence of the disease is highest in Caucasians, Europeans and women. The natural history of autoimmune hepatitis shows a poor prognosis, with frequent progression to cirrhosis and hepatic insufficiency in untreated patients. The occurrence of hepatocellular carcinoma is rare and is found only in long-standing cirrhosis. Corticosteroids as monotherapy or in combination with azathioprine are the treatments of choice; different therapeutic schedules and particularities of treatment for pregnant women and children have been established. To avoid treatment-associated adverse effects, alternative therapies have been proposed, including ciclosporin, budesonide, tacrolimus, mycophenolate mofetil, ursodeoxycholic acid, methotrexate, cyclophosphamide, mercaptopurine and free radical scavengers. Liver transplantation is indicated for patients refractory to or intolerant of immunosuppressive therapy.

Autoimmune liver disease. Current standards, future directions

The diagnosis and management of autoimmune hepatitis continues to evolve as new diagnostic tests and new therapies are added to the armamentarium. Also encouraging are the advances in the understanding of the human immune system and its involvement in the origin and course of auto immune diseases in general and in the variants of autoimmune liver disease. Promising changes are expected in the next few years as new medications become available to the practicing hepatologist. New immune tests may allow therapies to be customized to patients, and antiviral therapies may also eventually be used in the management of this autoimmune liver diseases.

Drug therapy in the management of type 1 autoimmune hepatitis

Prednisone alone or in combination with azathioprine is the treatment of choice for severe type 1 autoimmune hepatitis. The combination regimen is preferred, especially in the elderly, because of a lower incidence of corticosteroid-related complications. Only patients with sustained severe laboratory abnormalities, bridging necrosis or multilobular necrosis on histological assessment, and/or incapacitating symptoms, have absolute indications for treatment based on controlled clinical trials. The institution of therapy must be individualised in other patients, based mainly on symptoms and disease behaviour. Serum aspartate aminotransferase and gamma-globulin levels are the most useful indices to monitor during therapy. Liver tissue examination is the best method of evaluating completeness of response. Most patients enter remission, but relapse occurs in 50 to 86% after drug withdrawal. Maintenance therapy with low dosages of prednisone or azathioprine can be used long term in patients who have relapsed repeatedly. Inability to achieve remission after 3 years (incomplete response), deterioration during therapy (treatment failure) and drug toxicity are unsatisfactory responses that warrant alternative strategies. Liver transplantation is effective in managing decompensated disease, but recurrence of autoimmune hepatitis after transplantation is possible. Tacrolimus and budesonide are promising new drugs.

Diagnosis and therapy of autoimmune liver disease

The diagnostic criteria for autoimmune hepatitis have been codified by international consensus. Standardized clinical criteria or a scoring system that grades each relevant feature secure the diagnosis. Three types of autoimmune hepatitis have been proposed based on immunoserologic markers, but various forms exist. Multiple autoantibodies have diagnostic capability, but their clinical relevancy remains uncertain. Prednisone alone or in combination with azathioprine is effective therapy in most patients. Poor outcomes justify alternative strategies and evaluation of promising new drugs.

In vitro effect of TP-1 (a calf thymic extract) on suppressor T-cell function of patients with autoimmune chronic active hepatitis

Concanavalin A-activated T-lymphocyte suppression of IgG production was found to be significantly impaired in patients with untreated active autoimmune chronic hepatitis when compared to normals or patients with inactive disease. When the dose-response effect of TP-1, a calf thymic extract, on in vitro suppressor cell activity was assessed, lymphocytes from six out of eight patients with previously reduced suppressor cell function showed a significant improvement, while over a similar range the suppressor cell activity of most normal controls declined. These results support the possibility that defective immunoregulation in patients with autoimmune chronic active hepatitis may be related to a deficiency in thymic hormone levels.

Effect of thymosin immunostimulation with and without corticosteroid immunosuppression on chimpanzee hepatitis B carriers

Carriers of hepatitis B surface antigen (HBsAg) are at a high personal risk of developing chronic hepatitis, cirrhosis, and primary hepatocellular carcinoma, and they pose a potential health threat to others. Accordingly, erradication of the carrier state is an important therapeutic goal. Several categories of drugs have been evaluated for this purpose, with, at best, limited success. The immune stimulants constitute a drug group considered to have potential benefit, since altered cell-mediated immunity (CMI) appears to have a pathogenic role in the perpetuation of the carrier state. One such immune stimulant is the thymic hormone, thymosin, which is known to enhance suppressor T-cell activity. We therefore examined its possible therapeutic role by evaluating its effect on four chronic HBsAg- and hepatitis B e antigen (HBeAg)-positive chimpanzees. After baseline biochemical, serological, immunological, and histochemical studies were conducted, all four chimpanzees received parenteral thymosin for a period of 10-14 weeks; two of them were pretreated for 4 weeks with corticosteroids. All four were then reevaluated in the same manner at regular intervals during the 14-week period. Neither immunosuppression nor immunostimulation significantly affected biochemical, serological, or histological measures. Indices of CMI were altered, however: both T4 and T8 cells increased with thymosin treatment, although the T4/T8 ratio declined because of the relatively greater increase of the T8 than of the T4 cells. Thymosin did not affect the mitogen assays. Thus, while immunostimulation with thymosin did slightly alter CMI, it had no affect on the HBsAg carrier state or on measures of chronic hepatitis, even when preceded by corticosteroid immunosuppression.