TPMT testing before azathioprine therapy?

Long-term efficacy and safety of tailored immunosuppressive therapy in immune-mediated biopsy-proven myocarditis: A propensity-weighted study

AIMS

Standardized immunosuppressive therapy (IS) had been previously investigated in biopsy-proven (BP) lymphocytic myocarditis with heart failure (HF). This study evaluated efficacy and safety of tailored IS in BP immune-mediated myocarditis, irrespective of histology and clinical presentation.

METHODS AND RESULTS

Consecutive BP myocarditis patients treated with long-term tailored IS on top of optimal medical therapy (OMT), were compared with OMT non-IS controls using propensity-score weighting. The primary outcome was a composite of death or heart transplant, the secondary outcome was a composite of biventricular function, New York Heart Association (NYHA) class variation, and relapse. IS was managed by a multidisciplinary Cardioimmunology Team, involved a safety checklist and active patients' education. Ninety-one IS patients were compared with 267 non-IS patients. IS patients more frequently had systemic immune-mediated diseases (35% vs. 9.7%), lower baseline echocardiographic left ventricular ejection fraction (35% vs. 43%), lower right ventricular fractional area change (34% vs. 41%) and higher frequency of active lymphocytic, eosinophilic and giant cell myocarditis (71% vs. 58%, 12% vs. 1.1%, and 6.6% vs. 1.5%, respectively). At 5-year follow up, no difference was observed in the primary outcome (survival rate 93% in IS vs. 87% in non-IS), but IS patients had a higher relapse rate. Thus, IS patients, with a lower biventricular function and a higher risk profile at baseline, presented similar biventricular function and NYHA class to non-IS patients at follow-up. Minor adverse drug reactions occurred in 13% of patients, all resolved with therapy switch.

CONCLUSIONS

Prolonged tailored IS is effective and safe in BP immune-mediated myocarditis irrespective of histology and clinical presentation.

Advancements in autoimmune hepatitis management: Perspectives for future guidelines

The first-line treatment for autoimmune hepatitis involves the use of prednisone or prednisolone either as monotherapy or in combination with azathioprine (AZA). Budesonide has shown promise in inducing a complete biochemical response (CBR) with fewer adverse effects and is considered an optional first-line treatment, particularly for patients without cirrhosis; however, it is worth noting that the design of that study favored budesonide. A recent real-life study revealed higher CBR rates with prednisone when equivalent initial doses were administered. Current guidelines recommend mycophenolate mofetil (MMF) for patients who are intolerant to AZA. It is important to mention that the evidence supporting this recommendation is weak, primarily consisting of case series. Nevertheless, MMF has demonstrated superiority to AZA in the context of renal transplant. Recent comparative studies have shown higher CBR rates, lower therapeutic failure rates, and reduced intolerance in the MMF group. These findings may influence future guidelines, potentially leading to a significant modification in the first-line treatment of autoimmune hepatitis. Until recently, the only alternative to corticosteroids was lifelong maintenance treatment with AZA, which comes with notable risks, such as skin cancer and lymphoma. Prospective trials are essential for a more comprehensive assessment of treatment suspension strategies, whether relying on histological criteria, strict biochemical criteria, or a combination of both. Single-center studies using chloroquine diphosphate have shown promising results in significantly reducing relapse rates compared to placebo. However, these interesting findings have yet to be replicated by other research groups. Additionally, second-line drugs, such as tacrolimus, rituximab, and infliximab, should be subjected to controlled trials for further evaluation.

Therapeutic effects of biological treatments on AA amyloidosis associated with inflammatory bowel disease: a case report and literature review

AA amyloidosis is a rare and significant complication of long-term inflammation that can be caused by a variety of disorders, including inflammatory bowel disease, and is linked to an increased risk of morbidity and mortality. To date, there has been no effective direct treatment, and treatment aims at treating the underlying condition with potent immunosuppression to limit inflammatory activity and, as a result, switch off amyloidogenesis. Theoretically, biological treatment can control AA amyloidosis by inducing and maintaining inflammatory bowel disease remission and inhibiting the synthesis of Serum Amyloid A, which is an acute phase reactant and precursor protein of AA amyloidosis that accumulates in the organs. We report the first case of ustekinumab's therapeutic effect after infliximab's loss of response in AA amyloidosis associated with Crohn's disease. We also conducted a literature review of the therapeutic effect of biological treatment on AA amyloidosis.

Incidence of Myelotoxicity and Other Adverse Effects Related to Thiopurine Starting in Patients with Inflammatory Bowel Disease: Retrospective Observational Study in a Third-Level Hospital

BACKGROUND AND OBJECTIVES

Thiopurines are an effective treatment for the maintenance of remission in inflammatory bowel disease (IBD). They can present adverse effects (AEs), with myelotoxicity being the most relevant. This study aims to determine the incidence of AEs related to the starting of thiopurines in our centre.

METHODOLOGY

Retrospective study. The AEs in patients that were started on thiopurines between January 2016 and June 2020 were registered, with a two-year follow-up. The mean and standard deviation were used to describe the quantitative variables, and percentages and confidence intervals were used for the qualitative variables. The statistical significance was set at a p-value < 0.05.

RESULTS

98 patients were included, with 64 AEs detected in 48 patients (49%). Most of the AEs appeared in the first 6 months. The most relevant were: 21 neutropenia (21.4%), 19 hypertransaminasemia (19.4%), 13 digestive intolerances (13.2%), 6 acute pancreatitis (6.12%), 3 phototoxicity (3%), and 2 unknown origin fevers (2%). In 29 patients (29.4%) the treatment had to be suspended due to AEs. In 11 cases (11.2%), azathioprine (AZA) was switched to 6-mercaptopurine (6 MP) as 5 showed tolerance and 6 patients needed suspension due to AEs. Eight patients required hospital admission, but none of them needed intensive care unit admission. There were no fatal adverse effects.

CONCLUSIONS

Thiopurines are a safe drug with few AEs, especially after the first months of treatment. These results suggest that periodic analytic follow-up may not be necessary after the initial period of treatment.

Immunosuppressive Therapy of Biopsy-Proven, Virus-Negative, Autoimmune/Immune-Mediated Myocarditis-Focus on Azathioprine: A Review of Existing Evidence and Future Perspectives

The use of immunosuppressive therapy (IT) in biopsy-proven, autoimmune/immune-mediated (AI), virus-negative myocarditis has become the standard of care. In particular, according to recent guidelines, azathioprine (AZA), in association with steroids, is a cornerstone of first-line therapy regimens. IT may have a crucial impact on the natural history of AI myocarditis, preventing its progression to end-stage heart failure, cardiovascular death, or heart transplantation, provided that strict appropriateness and safety criteria are observed. In particular, AZA treatment for AI virus-negative myocarditis requires the consideration of some crucial aspects regarding its pharmacokinetics and pharmacodynamics, as well as a high index of suspicion to detect its overt and/or subclinical side effects. Importantly, besides a tight teamwork with a clinical immunologist/immuno-rheumatologist, before starting IT, it is also necessary to carry out a careful "safety check-list" in order to rule out possible contraindications to IT and minimize patient's risk. The aim of this review is to describe the pharmacological properties of AZA, as well as to discuss practical aspects of its clinical use, in the light of existing evidence, with particular regard to the new field of cardioimmunology.

Knowing when to use steroids, immunosuppressants or biologics for the treatment of sarcoidosis

Introduction: Care of patients with sarcoidosis requires familiarity with its natural history as well as of various immunosuppressants employed in its treatment. We would like to share our approach to management based on our experience and understanding of the relevant literature.Areas covered: Asymptomatic patients with pulmonary sarcoidosis ought to be managed conservatively. Systemic sarcoidosis with burdensome symptoms usually responds to corticosteroids, but one needs to consider the risk of long-term steroid toxicity as well as relapse. Rapidly tapering steroids can decrease cumulative exposure without compromising efficacy. Steroid-sparing anti-sarcoidosis (SSAS) agents take longer to act and are associated with unique but mostly reversible toxicities. Used judiciously and with careful monitoring, they effectively suppress granulomatous inflammation. Patients intolerant of or failing to improve with a particular drug can be switched to another, and occasionally combination therapy with two SSAS agents might prove effective. A small proportion of patients are refractory, but often achieve control and sometimes remission with stepping up to biologic therapy.Expert opinion: Adopting a strategy of early SSAS therapy ought to effectively control sarcoidosis and avoid harm from prolonged corticosteroid dosing.

Pharmacogenetics: A strategy for personalized medicine for autoimmune diseases

For many years, a considerable number of patients with autoimmune diseases (ADs) have suffered from a lack of drug response and drug-related toxicity. Despite the emergence of new therapeutic options such as biological agents, patients continue to struggle with these problems. Unfortunately, new challenges, including the paradoxical effects of biological drugs, have complicated the situation. In recent decades, efforts have been made to predict drug response as well as drug-related side effects. Thanks to the many advances in genetics, evaluation of markers to predict drug response/toxicity before the initiation of treatment may be an avenue toward personalizing treatments. Implementing pharmacogenetics and pharmacogenomics in the clinic could improve clinical care; however, obstacles remain to effective personalized medicine for ADs. The present study attempted to clarify the concept of pharmacogenetics/pharmacogenomics for ADs. After an overview on the pathogenesis of the most common types of treatments, this paper focuses on pharmacogenetic studies related to the selected ADs. Bridging the gap between pharmacogenetics and personalized medicine is also discussed. Moreover, the advantages, disadvantages and recommendations related to making personalized medicine practical for ADs have been addressed.

Hepatic involvement in sarcoidosis

Sarcoidosis is a multisystem granulomatous disease of unknown etiology. Liver is frequently involved in the pathological process. Wide range of clinical manifestations can be seen: from asymptomatic lesion with normal liver function tests to cirrhosis with portal hypertension. Biopsy plays the key role in diagnosis of the hepatic sarcoidosis. It is essential for morphological diagnosis to exclude other causes of granulomatous liver disease, most often - primary biliary cholangitis. Nowadays there are no standard treatment protocols for patients with hepatic sarcoidosis.

Screening and vaccinations in patients requiring systemic immunosuppression: an update for dermatologists

Immunomodulatory agents are becoming an increasingly important tool in the dermatologist's armamentarium against autoimmune and auto-inflammatory conditions. This review addresses the guidelines for vaccination and screening studies prior to the initiation of immunomodulatory agents. Included are discussions of vaccination schedules, hepatitis vaccination and screening, tuberculosis screening, and specific screening recommendations for antimalarials, azathioprine, cyclosporine, methotrexate, mycophenolate mofetil, tumor necrosis factor-α inhibitors, and newer medications like apremilast and tofacitinib.

Clinical presentation and protocol for management of hepatic sarcoidosis

The liver is one of the most commonly involved extrapulmonary sites in sarcoidosis. Hepatic sarcoidosis has a broad range of presentations from scattered, asymptomatic noncaseating granulomas with normal liver enzymes, which are very common in patients with known pulmonary sarcoidosis, to portal hypertension and cirrhosis, which are relatively uncommon. Diagnosis is based on a combination of clinical, laboratory and histological manifestations. The authors' protocol for management of patients with suspected sarcoidosis of the liver without focal lesions includes a transjugular liver biopsy with portal pressure measurements to confirm the diagnosis, rule out coexisting liver diseases and to identify select patients with fibrosis or portal hypertension for consideration of immunosuppression. Steroids and azathioprine are the preferred agents and methotrexate is not recommended.

Implementation of TPMT testing

The activity of the enzyme thiopurine methyltransferase (TPMT) is regulated by a common genetic polymorphism. One in 300 individuals lack enzyme activity and 11% are heterozygous for a variant low activity allele and have an intermediate activity. The thiopurine drugs azathioprine, mercaptopurine and thioguanine are substrates for TPMT; these drugs exhibit well documented myelosuppressive effects on haematopoietic cells and have a track record of idiosyncratic drug reactions. The development of severe bone marrow toxicity, in patients taking standard doses of thiopurine drugs, is associated with TPMT deficiency whilst the TPMT heterozygote is at an increased risk of developing myelosuppression. Factors influencing TPMT enzyme activity, as measured in the surrogate red blood cell, are discussed in this review to enable an appreciation of why concordance between TPMT genotype and phenotype is not 100%. This is particularly important for lower/intermediate TPMT activities to avoid misclassification of TPMT status. TPMT testing is now widely available in routine service laboratories. The British National Formulary suggests TPMT testing before starting thiopurine drugs. Dermatologists were quick to adopt routine TPMT testing whilst gastroenterologists do not specifically recommend TPMT screening. TPMT testing is mandatory prior to the use of mercaptopurine in childhood leukaemia. Thiopurine drug dose and other treatment related influences on cell counts explain some of the differing recommendations between clinical specialities. TPMT testing is cost-effective and the major role is in the identification of the TPMT deficient individual prior to the start of thiopurine drugs.

How genetic variation affects patient response and outcome to therapy for psoriasis

Psoriasis is a prevalent chronic inflammatory condition that affects the skin. There are many treatments available for psoriasis but they are not universally effective and some have associated toxicities. Pharmacogenetics and pharmacogenomics explore the relationship between individual genetic variation and drug effect to allow targeted 'personalized' therapy for patients. There has been very limited pharmacogenetic research regarding psoriasis, with most limited to small retrospective case-control studies looking at single-nucleotide polymorphisms in candidate genes involved in drug pharmacokinetics. We review the pharmacogenetic investigation of treatments for psoriasis to date, including emerging pharmacogenomic studies. In addition, we discuss how such genetic data could be incorporated into routine clinical practice and future areas for development in this field.

Thiopurine S-methyltransferase (TPMT) assessment prior to starting thiopurine drug treatment; a pharmacogenomic test whose time has come

Thiopurine S-methyltransferase (TPMT) is involved in the metabolism of thiopurine drugs. Patients that due to genetic variation lack this enzyme or have lower levels than normal, can be adversely affected if normal doses of thiopurines are prescribed. The evidence for measuring TPMT prior to starting patients on thiopurine drug therapy has been reviewed and the various approaches to establishing a service considered. Until recently clinical guidelines on the use of the TPMT varied by medical specialty. This has now changed, with clear guidance encouraging clinicians to use the TPMT test prior to starting any patient on thiopurine therapy. The TPMT test is the first pharmacogenomic test that has crossed from research to routine use. Several analytical approaches can be taken to assess TPMT status. The use of phenotyping supported with genotyping on selected samples has emerged as the analytical model that has enabled national referral services to be developed to a high level in the UK. The National Health Service now has access to cost-effective and timely TPMT assay services, with two laboratories undertaking the majority of the work at national level and with several local services developing. There appears to be adequate capacity and an appropriate internal market to ensure that TPMT assay services are commensurate with the clinical demand.

Expressing thiopurine S-methyltransferase activity as units per litre of whole-blood overcomes misleading high results in patients with anaemia

BACKGROUND

Thiopurine S-methyltransferase (TPMT) phenotype analysis, expressed as TPMT activity, is established as a routine pharmacogenomic test to screen patients prior to initiating thiopurine drug therapy. Conventionally measured TPMT activity is corrected for red blood cell (RBC) parameters. Here we present evidence that supports the simplification of the TPMT assay: by expressing TPMT activity in mU/L whole blood, without undertaking any haemoglobin (Hb) correction.

METHODS

Hb concentrations were compared in consecutive samples that had been received for TPMT phenotype analysis and which were stratified into samples with high (n = 111) and samples with normal (n = 50) Hb-corrected enzyme activity. TPMT activity was also measured in samples received for full blood count determination, stratified into those with low (n = 50) and normal (n = 50) Hb. A reference interval for TPMT activity in mU/L was derived from a correlation between activity expressed in conventional units and that expressed in mU/L (n = 1563), supported by comparison with associated genotype (n = 201).

RESULTS

In the high TPMT activity group, 83% of specimens had a low Hb concentration compared with 14% of specimens in the normal TPMT group. Samples with a low Hb concentration were found to have significantly higher Hb-corrected TPMT activity than samples with a normal Hb concentration: 83 versus 44 nmol 6-methyl thioguanine /g Hb/h, P < 0.0001. These results strongly suggest that misleading high Hb-corrected TPMT activity is found in anaemic patients. Based on the reference interval for enzyme activity of 70-150 mU/L, phenotype-genotype concordance compared well with the conventional approach (88% versus 89%). Furthermore, distribution of TPMT phenotypes with activity expressed in mU/L was identical: 0.5% deficient, 11% low, 86% normal and 2.5% high, to when it was expressed in conventional units.

CONCLUSION

Expressing TPMT activity in mU/L can overcome misleading high Hb-corrected TPMT results occurring in patients with anaemia, which could lead to inappropriate treatment. Removing the need to measure RBC indices further simplifies TPMT phenotyping, leading to a more robust assay, with reduced turn-around time and cost.

Management strategies for pulmonary sarcoidosis

SARCOIDOSIS IS A SYSTEMIC INFLAMMATORY CONDITION WITH AN UNEXPLAINED PREDILECTION FOR THE LUNG: over 90% of patients have radiographic or physiological abnormalities. Respiratory physicians therefore often manage patients, but any organ may be involved, with noncaseating granulomas the characteristic feature. Sarcoidosis is the commonest interstitial lung disease (ILD), differing from most other ILDs in that many patients remain asymptomatic or improve spontaneously. Careful baseline assessment of disease distribution and severity is thus central to initial management. Subsequently, the unpredictable clinical course necessitates regular monitoring. Sarcoidosis occurs worldwide, with a high prevalence in Afro-Caribbeans and those of Swedish or Danish origin. African Americans also tend to have severe disease. Oral corticosteroids have been used since the 1950s, with evidence of short to medium response; more recent studies have examined the role of inhaled steroids. Long-term benefits of steroids remain uncertain. International guidelines published in 1999 represent a consensus view endorsed by North American and European respiratory societies. Updated British guidelines on interstitial lung disease, including sarcoidosis, were published in 2008. This review describes current management strategies for pulmonary disease, including oral and inhaled steroids, commonly used alternative immunosuppressant agents, and lung transplantation. Tumor necrosis factor alpha inhibitors are briefly discussed.