[Hepatotoxicity induced by new immunosuppressants]

Current Advancement of Immunomodulatory Drugs as Potential Pharmacotherapies for Autoimmunity Based Neurological Diseases

Dramatic advancement has been made in recent decades to understand the basis of autoimmunity-mediated neurological diseases. These diseases create a strong influence on the central nervous system (CNS) and the peripheral nervous system (PNS), leading to various clinical manifestations and numerous symptoms. Multiple sclerosis (MS) is the most prevalent autoimmune neurological disease while NMO spectrum disorder (NMOSD) is less common. Furthermore, evidence supports the presence of autoimmune mechanisms contributing to the pathogenesis of amyotrophic lateral sclerosis (ALS), which is a neurodegenerative disorder characterized by the progressive death of motor neurons. Additionally, autoimmunity is believed to be involved in the basis of Alzheimer’s and Parkinson’s diseases. In recent years, the prevalence of autoimmune-based neurological disorders has been elevated and current findings strongly suggest the role of pharmacotherapies in controlling the progression of autoimmune diseases. Therefore, this review focused on the current advancement of immunomodulatory drugs as novel approaches in the management of autoimmune neurological diseases and their future outlook.

Drug-Induced Liver Injury After Liver Transplantation

Drug-induced liver injury (DILI) is an adverse reaction to many drugs in common use that in a liver transplantation (LT) recipient may cause graft dysfunction and may even lead to graft loss and the need for retransplantation. However, several potential clinical scenarios, such as graft rejection and infection, can confound the diagnosis of suspected DILI in the setting of LT. This makes causal assessment of a new liver injury more uncertain and has traditionally precluded collection of bona fide cases of DILI affecting LT patients in prospective DILI registries and cohorts. Although no studies have yet determined a greater susceptibility of the transplant patient to DILI, these patients nevertheless present certain risk factors that can theoretically increase the risk of DILI. These include the fact that these patients are polymedicated, use drugs that are potentially hepatotoxic, and can have coexisting hepatitis B or C viruses in addition to other factors found in nontransplant patients, such as genetic variants. Therefore, awareness is crucial of any potential hepatotoxic effect of drugs used in the LT recipient and their possible implication in any case of liver dysfunction. In the present article, we review the most common drugs used in LT recipients from a liver safety perspective and address the main pitfalls in attributing causality in this clinical setting. We also affirm the need for further research and collaboration in this somewhat neglected topic in the field of DILI.

Role of enterohepatic recirculation in drug disposition: cooperation and complications

Enterohepatic recirculation (EHC) concerns many physiological processes and notably affects pharmacokinetic parameters such as plasma half-life and AUC as well as estimates of bioavailability of drugs. Also, EHC plays a detrimental role as the compounds/drugs are allowed to recycle. An in-depth comprehension of this phenomenon and its consequences on the pharmacological effects of affected drugs is important and decisive in the design and development of new candidate drugs. EHC of a compound/drug occurs by biliary excretion and intestinal reabsorption, sometimes with hepatic conjugation and intestinal deconjugation. EHC leads to prolonged elimination half-life of the drugs, altered pharmacokinetics and pharmacodynamics. Study of the EHC of any drug is complicated due to unavailability of the apposite model, sophisticated procedures and ethical concerns. Different in vitro and in vivo methods for studies in experimental animals and humans have been devised, each having its own merits and demerits. Involvement of the different transporters in biliary excretion, intra- and inter-species, pathological and biochemical variabilities obscure the study of the phenomenon. Modeling of drugs undergoing EHC has always been intricate and exigent models have been exploited to interpret the pharmacokinetic profiles of drugs witnessing multiple peaks due to EHC. Here, we critically appraise the mechanisms of bile formation, factors affecting biliary drug elimination, methods to estimate biliary excretion of drugs, EHC, multiple peak phenomenon and its modeling.

Immune-mediated diseases: what can be found in the oral cavity?

Immune-mediated diseases frequently affect oral mucosa, which may often be the first site of clinical manifestation. In this review, we describe the most important oral lesions related to inflammatory disorders and present their management and novel therapies. The review is based on an open PubMed literature search from 1980 to 2012 with relevant keywords. Pemphigus vulgaris, oral lichen planus, cicatricial pemphigoid, erythema multiforme, Stevens-Johnson syndrome, systemic lupus erythematosus, Sjögren's syndrome, and linear IgA dermatosis are the immune-mediated diseases with oral manifestations discussed. Etiology is unknown in most of these diseases, but recently some of them have been found to share common genes. Modern treatment of these diseases is based on drugs that interfere along the pathogenic mechanisms instead of the still commonly used palliative measures. However, the immunomodulatory drugs may also cause oral side effects, complicating the clinical picture. Therefore, consulting dental or oral medicine specialists can be necessary in some cases with various immune-mediated diseases.

Drug-induced autoimmune liver disease: A diagnostic dilemma of an increasingly reported disease

The aetiology of autoimmune hepatitis (AIH) is uncertain but the disease can be triggered in susceptible patients by external factors such as viruses or drugs. AIH usually develops in individuals with a genetic background mainly consisting of some risk alleles of the major histocompatibility complex (HLA). Many drugs have been linked to AIH phenotypes, which sometimes persist after drug discontinuation, suggesting that they awaken latent autoimmunity. At least three clinical scenarios have been proposed that refers to drug- induced autoimmune liver disease (DIAILD): AIH with drug-induced liver injury (DILI); drug induced-AIH (DI-AIH); and immune mediated DILI (IM-DILI). In addition, there are instances showing mixed features of DI-AIH and IM-DILI, as well as DILI cases with positive autoantibodies. Histologically distinguishing DILI from AIH remains a challenge. Even more challenging is the differentiation of AIH from DI-AIH mainly relying in histological features; however, a detailed standardised histologic evaluation of large cohorts of AIH and DI-AIH patients would probably render more subtle features that could be of help in the differential diagnosis between both entities. Growing information on the relationship of drugs and AIH is being available, being drugs like statins and biologic agents more frequently involved in cases of DIAILD. In addition, there is some evidence on the fact that patients diagnosed with DIAILD may have had a previous episode of hepatotoxicity. Further collaborative studies in DIAILD will strengthen the knowledge and understanding of this intriguing and complex disorder which might represent different phenotypes across the spectrum of disease.

Treatment of ankylosing spondylitis with TNF inhibitors does not have adverse effect on results of liver function tests: a longitudinal study

AIM

To retrospectively investigate and compare the effects of tumor necrosis factor alpha inhibitors (TNFi) on hepatic enzymes in ankylosing spondylitis (AS) patients.

METHODS

A retrospective analysis of the records of 94 AS (66 male, 28 female) patients using TNFi was performed. Patients' clinical data, Bath Ankylosing Spondylitis Disease Activity (BASDAI) scores, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels were all examined. Liver function test (LFTs) results of patients before the treatment and 3, 6 and 12 months after treatment with TNFi were investigated. Aspartate transaminase (AST) and alanine transaminase (ALT) levels were investigated as indicators of LFTs.

RESULTS

The TNFi drugs used were infliximab (n = 28), adalimumab (n = 32) and etanercept (n = 34). Pre-treatment values of ESR, CRP and BASDAI scores were 28.3 ± 20.1 mm/h, 1.5 ± 1.2 ng/dL and 5.2 ± 0.8, respectively. Following TNFi use there was a statistically significant decrease in disease activity score (P = 0.001). There was a significant increase in LFT at the third month evaluation compared to the initial values, while the average value was within normal range (baseline AST 19.6 ± 10.8 U/L, ALT 19.1 ± 6.4 U/L, third month AST 31.3 ± 21.6 U/L, ALT 28.1 ± 18.1 U/L, P = 0.001). Drug group comparison analysis revealed a significant difference in the adalimumab group value at the end of the first year, but no other significant difference in the data for the other months (P > 0.05). No significant correlation was determined between initial disease activity scores and LFT.

CONCLUSION

TNFi use-associated rises in hepatic enzymes were determined compared to pre-treatment but the mean values remained within normal limits. Considering the cases in the literature, in daily practice patients must be carefully monitored for liver function before treatment and at follow-up.

Immunomodulatory drugs: oral and systemic adverse effects

OBJECTIVE

The main objectives are to present the different adverse effects of the immunomodulatory drugs that can impair the quality of life of the immunosuppressed patients and study the impact of immunomodulation on oral diseases. Immunomodulatory drugs have changed the treatment protocols of many diseases where immune functions play a central role, such as rheumatic diseases. Their effect on oral health has not been systematically investigated, however.

STUDY DESIGN

We review current data on the new immunomodulatory drugs from the oral health perspective based on open literature search of the topic.

RESULTS

These target specific drugs appear to have less drug interactions than earlier immunomodulating medicines but have nevertheless potential side effects such as activating latent infections. There are some data showing that the new immunomodulatory drugs may also have a role in the treatment of certain oral diseases such as lichen planus or ameliorating symptoms in Sjögren's syndrome, but the results have not been overly promising.

CONCLUSION

In general, data are sparse of the effect of these new drugs vs. oral diseases and there are no properly powered randomized controlled trials published on this topic.

On the performance of trimetazidine and vitamin e as pharmacoprotection agents in cyclosporin a-induced toxicity

The immunosuppressant drug cyclosporin A (CyA) has been used in diseases with immunological basis and in transplant patients. Nephrotoxicity and hepatotoxicity are the main adverse effects of this drug. To find a protective drug against those effects we assayed the cardioprotector Trimetazidine (TMZ) and vitamin E, used as nutritional supplements to alleviate oxidative stress. Six groups of eight male Wistar rats each were prepared (groups A-F): A, control; B, vitamin E (10 mg/Kg/day); C, TMZ (20 mg/Kg/day); D, 25 mg/Kg/day CyA; E, CyA and vitamin E (25 mg/Kg/day CyA + 10 mg/Kg/day Vit E); F, TMZ for 20 days (20 mg/kg/day); and then CyA (25 mg/kg/day) and TMZ (20 mg/Kg/day). The experiment lasted 120 days. The exposure of rats to CyA promoted nephrotoxicity and hepatotoxicity with an increase in serum urea, creatinine, and glutamate dehydrogenase (GLDH). Structural and ultrastructural studies of liver and kidney were performed. Group D showed adverse effects induced by CyA since statistically significant differences were found with respect to the control group (A). Vitamin E (E) showed no protective effect. Pretreatment with TMZ (F) attenuated the adverse effects of CyA. We conclude that CyA-induced nephrotoxicity and hepatotoxicity are attenuated by the cytoprotective effect of TMZ. TMZ inhibits the reabsorption and, consequently, the accumulation of CyA in the cell. The antioxidant capacity of vitamin E did not improve the effect of CyA.

Prevalence and risk factors for liver biochemical abnormalities in Canadian patients with systemic lupus erythematosus

OBJECTIVE

To determine the prevalence of abnormal liver enzymes in patients with systemic lupus erythematosus (SLE) and whether further investigations were done, and the differences in SLE-related and/or metabolic factors in patients with and without liver biochemical abnormalities.

METHOD

Patients from the University of Toronto Lupus Clinic who met at least 4 of the American College of Rheumatology classification criteria for SLE and had 1.5 times the upper limit for aspartate transaminase or alanine transaminase on 2 consecutive visits within a 2-year period were matched with controls for age, sex, and SLE duration. Demographic, clinical, and laboratory data were extracted at the time of the first appearance of liver enzyme abnormality for the cases and at the reference point for the controls.

RESULTS

From the 1533 patients reviewed, 134 (8.7%) met the inclusion criteria. Thirty of these patients were evaluated by a hepatologist, 75 had imaging studies (41 were done specifically for liver investigation), and 13 had liver biopsies. Results based on these investigations showed 31 fatty livers, 35 cases of drug-induced hepatotoxicity, 10 autoimmune etiologies, and 3 cases of viral hepatitis. Compared to controls, cases were higher in body mass index, anti-dsDNA antibody, prevalence of hypertension, antiphospholipid syndrome, and use of immunosuppressive medication, especially azathioprine and methotrexate; they were lower in IgM.

CONCLUSION

Metabolic abnormalities such as obesity and hypertension and hepatotoxic effects of medication used to treat SLE may contribute more than SLE-related factors to liver biochemical abnormalities in patients with SLE.