Propylthiouracil-associated liver failure presenting as probable autoimmune hepatitis in a child with Graves' disease

Differential characteristics in drug-induced autoimmune hepatitis

BACKGROUND AND AIM

Drug-induced autoimmune hepatitis (DIAIH) is an adverse effect associated with several drugs that usually occurs acutely, with variable latency, and it may potentially be mortal. There are a few reports and studies about DIAIH.

METHODS

This was an analytical study of a retrospective cohort of patients, discriminated according to idiopathic or drug-induced etiology, followed up for a 7-year period until 31 December 2016.

RESULTS

A total of 190 patients were selected for the analysis, 12 (6.3%) with DIAIH. The two main drugs related to DIAIH were nitrofurantoin, n = 8 (67%), and NSAID, n = 2 (17%), constituting 84% of the cases. There were no significant differences in seropositivity between AIH with DIAIH in antinuclear antibodies (ANA) and anti-smooth muscle antibodies (ASMA) antibodies, with 82.6% versus 82.6% and 34% versus 16%, respectively. The fibrosis stages were similar, except for the F4 stage, in a greater proportion in AIH. None of the patients with DIAIH had cirrhosis or developed it during follow-up, but it was present in 42.1% of the AIH cases at diagnosis (P = 0.003). Biochemical remission with management was higher in DIAIH but not significant (91.7% vs 80.9%, P = 0.35). The definitive interruption of immunosuppression was successfully performed in 25% of those with DIAIH without relapses but was only possible in 2.8% in AIH (P < 0.001) with 32 cases of relapses.

CONCLUSION

DIAIH constitutes a minor proportion of AIH. The clinical and histological characteristics may be similar; DIAIH patients have a greater chance of having treatment suspended with a low risk of relapse, progression to cirrhosis, or need for liver transplant.

Investigating Antithyroid Effects of Propylthiouracil on the Ischemia and Reperfusion Injury in Rat' Kidney and Determining the Role of Nitric Oxide in Mediating this Effect

BACKGROUND

Renal ischemia/reperfusion injury (IRI) is a major problem in renal transplantation, which occurs during the process of organ retrieval and storage, and is closely associated with acute rejection episodes and late allograft failure. Recent studies have revealed a new phenomenon called "chemical preconditioning" that can induce tolerance against the ischemic stress via a variety of proposed pathways especially nitric oxide (NO) system. Propylthiouracil (PTU) is suggested to modulate the intracellular NO signaling.

OBJECTIVES

In this study, we investigated the preconditioning properties of chronic pretreatment with PTU in preventing renal IRI. In addition, we evaluated the involvement of NO pathway.

MATERIALS AND METHODS

Sixty adult male Wistar rats were allocated into six groups. All groups underwent right nephrectomy 15 days before intervention. In groups 1 (Chronic PTU + L-NG-nitro arginine methyl ester [L-NAME]) and 2 (Chronic PTU) oral PTU (500 mg/L in water) treatment was started 15 days before right nephrectomy to achieve the therapeutic plasma level of PTU. Fourteen days after nephrectomy, animals received either L-NAME (10 mg/kg) or its vehicle and renal IRI was induced 45 minutes later. Groups 3 and 4 (Control) received respectively L-NAME (10 mg/kg) and its vehicle 45 minutes before IRI. The last two groups were normal sham operated rats and PTU + sham. Rats were killed 24 hours after IRI. The blood samples were collected and assessed for serum blood urea nitrogen (BUN) and creatinine (Cr) level, and tissue samples were fixed in formalin for histopathologic scoring of tubular damage (H-score).

RESULTS

The mean BUN, Cr, and H-score of control group were 176.66 ± 12.24 mmol/L, 4.45 ± 0.44 μmol/L, and 83.5% ± 3.5%, respectively. Chronic pretreatment with PTU significantly improved BUN (40.4 ± 6.1 mmol/L), Cr (0.96 ± 0.068 μmol/L), and H-score (7.83% ± 4.02%) in IRI animals in comparison to those that were not treated with chronic PTU (P < 0.001) and L-NAME; however, it did not completely reversed the chronic PTU-induced protection (BUN, 93.33 ± 12.22 mmol/L; Cr, 2.7 ± 1.15 μmol/L, and H-score, 24.83% ± 3.5%). There was no significant difference between rats that were treated with L-NAME alone (group 5) and the control group.

CONCLUSIONS

Our study demonstrates that preconditioning of kidney with chronic PTU administration protects renal tissue against IRI and this phenomenon was mediated through NO system. The results suggest a potential indication for using PTU to protect the kidney before transplantations and to reduce the risk of tissue rejection afterwards.

Propylthiouracil, and methimazole, and carbimazole-related hepatotoxicity

INTRODUCTION

Propylthiouracil (PTU) has been used for the treatment of hyperthyroidism since the 1940s, but over the years reports of significant hepatotoxicity have come forth, particularly in children. This led to a black box warning being issued by the US FDA in 2009, followed by a similar warning by the European Medicines Agency and the United Kingdom Medicines and Healthcare Regulatory Agency later that year.

AREAS COVERED

This article provides a concise review of the data on hepatotoxicity associated with the currently available antithyroid drugs: PTU, methimazole (MMI) and carbimazole. The differences in mechanism are examined in detail, as well as clinical presentation, management and monitoring. Use in special populations and trends in use of antithyroid medication are also discussed.

EXPERT OPINION

PTU is known to cause severe hepatic failure, particularly in children. Its use in children should be avoided. In adults, it is beneficial to use in the first trimester of pregnancy and thyroid storm. In the rest of the adult population, it should be used with caution. Carbimazole and MMI are associated with less severe hepatic injury and should be preferred when choosing thionamides as a treatment option.

Autoimmune hepatitis

Autoimmune hepatitis is a disease of the hepatic parenchyma that can present in acute or chronic forms. In common with many autoimmune diseases, autoimmune hepatitis is associated with non-organ-specific antibodies in the context of hepatic autoimmunity. This dichotomy has made definition of a unifying hypothesis in the pathophysiology of the disease difficult, although data from the past 8 years have drawn attention to the role of regulatory T cells. Several triggers have been identified, and the disease arises in genetically susceptible individuals. Clinical and biochemical remission is achievable in up to 85% of cases. For the remaining patients, alternative immunosuppression strategies are an option. Liver transplantation provides an excellent outcome for patients with acute liver failure or complications of end-stage liver disease, including hepatocellular carcinoma. Variant or overlapping syndromes are worthy of consideration when unexpected disease features arise.

Acute liver failure associated with propylthiouracil in a pregnant 26-year-old woman

It seems appropriate to use propylthiouracil to treat maternal hyperthyroidism during the first trimester of pregnancy. We present the case of a 26-year-old woman with acute liver failure associated with propylthiouracil during the first trimester of pregnancy. She was successfully treated without liver transplantation. Attention should be paid to the possible occurrence of propylthiouracil-induced hepatotoxicity even during the first trimester of pregnancy.

Propylthiouracil (PTU) Hepatoxicity in Children and Recommendations for Discontinuation of Use

Propylthiouracil (PTU) was introduced for clinical use in July 1947 for Graves' disease (GD) treatment. Over the 60 years that this medication has been used, reports of PTU-related liver failure and death have accumulated. On October 28, 2008, an expert panel evaluated PTU drug safety in children at the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) It is estimated that about 4000 pediatric patients per year with GD are being treated with antithyroid drugs (ATDs) in the United States, and up to 30% of pediatric patients with GD are being treated with PTU. The risk of severe PTU-induced liver failure is estimated as 1 in 2000-4000 children. The number of children developing reversible PTU-induced liver injury is estimated to be at least 1 in 200. Routine biochemical surveillance of liver function and hepatocellular integrity is not useful in identifying children who will develop liver failure. Children appear to be at higher risk for PTU-induced liver injury than adults. PTU should not be used as first line therapy for the treatment of GD in children. Current PTU use in children taking this medication should be stopped in favor of alternate therapies.

Drug-induced splenic enlargement

Splenomegaly results from different abnormal conditions susceptible to drugs. Their diagnosis is based on a history of exposure to a drug before the spleen enlargement. This paper reviews studies on drugs that may induce to splenomegaly. Drugs may provoke the enlargement of the spleen by direct effect on splenic cells or as a side effect of disturbances in other organs, such as the liver, or systems, such as the haematoimmunological system. Some drugs provoke severe haemolysis associated with splenomegaly. Another cause of spleen increasing in size is the venous congestion due to liver disturbance with portal vein occlusion as side complications of drugs. All these drug side effects are usually transitory and splenomegaly disappears when the medication is discontinued. This is a complex problem that must be better studied to be understood in order to prevent its occurrence and to find the best treatment.

Autoimmune hepatitis in children: diagnosis, pathology and treatment

Autoimmune hepatitis (AIH) is characterized by progressive inflammation of the liver and destruction of liver parenchyma. Rare in absolute terms, it is nevertheless an important cause of noninfectious chronic liver disease in children. In many ways, the diagnosis and treatment of children with AIH has changed little over the last 10 years. However, in recent years, steady progress in defining the genetic, immunologic and potential environmental triggers that underlie this disease, in addition to increasing experience with a wider array of therapeutic agents, promises to expand our understanding and ability to treat AIH effectively. This review will summarize the current clinical and pathophysiological understanding of AIH in children, along with therapeutic options.