Case Report of Isoniazid-Related Acute Liver Failure Requiring Liver Transplantation

Treatment of Psoriasis Patients with Latent Tuberculosis Using IL-17 and IL-23 Inhibitors: A Retrospective, Multinational, Multicentre Study

BACKGROUND

Tuberculosis has a major global impact. Immunocompetent hosts usually control this disease, resulting in an asymptomatic latent tuberculosis infection (LTBI). Because TNF inhibitors increase the risk of tuberculosis reactivation, current guidelines recommend tuberculosis screening before starting any biologic drug, and chemoprophylaxis if LTBI is diagnosed. Available evidence from clinical trials and real-world studies suggests that IL-17 and IL-23 inhibitors do not increase the risk of tuberculosis reactivation.

OBJECTIVE

To evaluate psoriasis patients with treated or untreated newly diagnosed LTBI who received IL-17 and IL-23 inhibitors and the tolerability/safety of tuberculosis chemoprophylaxis.

METHODS

This is a retrospective, observational, multinational study from a series of 14 dermatology centres based in Portugal, Spain, Italy, Greece and Brazil, which included adult patients with moderate-to-severe chronic plaque psoriasis and newly diagnosed LTBI who were treated with IL-23 or IL-17 inhibitors between January 2015 and March 2022. LTBI was diagnosed in the case of tuberculin skin test and/or interferon gamma release assay positivity, according to local guideline, prior to initiating IL-23 or IL-17 inhibitor. Patients with prior diagnosis of LTBI (treated or untreated) or treated active infection were excluded.

RESULTS

A total of 405 patients were included; complete/incomplete/no chemoprophylaxis was administered in 62.2, 10.1 and 27.7% of patients, respectively. The main reason for not receiving or interrupting chemoprophylaxis was perceived heightened risk of liver toxicity and hepatotoxicity, respectively. The mean duration of biological treatment was 32.87 ± 20.95 months, and only one case of active tuberculosis infection (ATBI) was observed, after 14 months of treatment with ixekizumab. The proportion of ATBI associated with ixekizumab was 1.64% [95% confidence interval (CI): 0-5.43%] and 0% for all other agents and 0.46% (95% CI 0-1.06%) and 0% for IL-17 and IL-23 inhibitors, respectively (not statistically significant).

CONCLUSIONS

The risk of tuberculosis reactivation in patients with psoriasis and LTBI does not seem to increase with IL-17 or IL-23 inhibitors. IL-17 or IL-23 inhibitors should be preferred over TNF antagonists when concerns regarding tuberculosis reactivation exists. In patients with LTBI considered at high risk for developing complications related to chemoprophylaxis, this preventive strategy may be waived before initiating treatment with IL-17 inhibitors and especially IL-23 inhibitors.

Isoniazid-Induced Acute Liver Failure Requiring Liver Transplantation

Tuberculosis (TB) is a contagious disease caused by the bacilli Mycobacterium tuberculosis complex. Currently, about a quarter of the world's population is infected with Mycobacterium tuberculosis. According to the World Health Organization, in 2018, Portugal had a TB incidence rate of about 24 cases per 100,000 inhabitants. It is estimated that 5-15% of individuals with latent TB infection progress to active TB. Isoniazid is one of the most widely used drugs for the treatment of active and latent TB. However, care must be taken with the possible development of toxicity, particularly hepatic. The authors report a case of a 60-year-old woman diagnosed with latent TB who started therapy with isoniazid. Five months later, she developed acute liver failure secondary to the drug, requiring liver transplantation, with a favorable clinical outcome. Thus, we intend to alert to the potential toxicities of isoniazid, establishing follow-up strategies in patients on this therapy.

A Case of Acute Liver Failure in a Patient on Isoniazid Prophylaxis for Latent Tuberculosis

Isoniazid (INH) is widely used for latent Mycobacterium tuberculosis despite the known risk of liver injury, with severe hepatitis occurring in up to 1% of patients. We report a patient who presented with two weeks of anorexia, nausea, and jaundice following six months of INH monotherapy for latent tuberculosis (TB). After other causes of liver injury were ruled out, she underwent a liver biopsy showing submassive necrosis, hepatocellular dropout, and lobular inflammation with no evidence of fibrosis. She was also found to have acute portal hypertension. She was diagnosed with drug-induced liver injury (DILI) and was treated with n-acetyl cysteine (NAC), ursodiol, and vitamin K. She recovered without the need for a liver transplant. This case supports the need for monitoring of liver tests in high-risk individuals on INH therapy to reduce the risk of hepatotoxicity.

A pilot study to investigate the utility of NAT2 genotype-guided isoniazid monotherapy regimens in NAT2 slow acetylators

Isoniazid is a therapeutic agent for the treatment of latent tuberculosis infection. Genetic variants in the N-acetyltransferase 2 (NAT2) are associated with the safety and pharmacokinetics of isoniazid. The study aimed to evaluate the safety and pharmacokinetics of a NAT2 genotype-guided regimen of isoniazid monotherapy. A randomized, open-label, parallel-group and multiple-dosing study was performed in healthy subjects. The subjects received isoniazid for 29 days. The NAT2 slow acetylators (NAT2*5/*5, -*5/*6, -*5/*7, -*6/*6, -*6/*7, -*7/*7) randomly received standard dose (300 mg, standard-treatment group) or reduced dose (200 mg, PGx-treatment group) of isoniazid. Also, all the NAT2 rapid acetylators (NAT2*4/*4) received isoniazid 300 mg (reference group). The safety and pharmacokinetics were evaluated during the study. The PGx-treatment group showed a more stable serum liver enzyme profile and a lower incidence of adverse drug reactions (ADRs) than the standard-treatment group. The emergence rates of ADRs were 12.5, 60 and 33.3% in the reference, standard-treatment and PGx-treatment groups, respectively. The PGx-treatment group showed higher plasma isoniazid concentrations than the reference group, although the PGx-treatment group received a reduced dose of isoniazid. Our results showed that a NAT2 genotype-guided regimen may reduce ADRs during isoniazid monotherapy without concern over insufficient drug exposure.

Risk of tuberculosis reactivation with interleukin (IL)-17 and IL-23 inhibitors in psoriasis - time for a paradigm change

Tuberculosis is an infectious disease with a major global impact, ranked in the top 10 mortality causes worldwide. In an immunocompetent individual, the host defence mechanisms control Mycobacterium tuberculosis infection and induce the latent form of the disease. However, in the presence of diseases or therapies, which exert an immunosuppressive effect, latent tuberculosis can be re-activated. Psoriasis is an immune-mediated, inflammatory disease, and its treatment has rapidly evolved over the last few years. It has long been recognized that the tumour necrosis factor (TNF)-α inhibitors are associated with increased risk of reactivation of latent tuberculosis infection. Thus, international guidelines have been suggesting tuberculosis screening before starting the treatment with all biological agents since then. In addition, the institution of chemoprophylaxis in the presence of latent tuberculosis and the annual screening for tuberculosis thereafter have also been indicated. However, anti-tuberculosis treatments can have significant side-effects and there are currently several contraindications to their use. The risk benefit of starting anti-tuberculous treatment should be carefully weighed up. The emergence of new biological drugs for the treatment of psoriasis, such as interleukin (IL)-17 and IL-23 inhibitors, has reignited the subject of tuberculosis reactivation as it is possible that IL-17 and 23 blockade do not carry the same risk of TB reactivation as TNF-α inhibitors. Although preclinical studies have shown that cytokines IL-17 and IL-23 have a possible role against infection with M. tuberculosis, data from clinical trials and post-marketing surveillance with drugs that inhibit these cytokines appear to suggest that they are not crucial to this response. In this article, we review the available data on tuberculosis reactivation after the treatment of psoriasis with IL-17 and IL-23 inhibitors, and its possible impact on the way we currently manage latent tuberculosis infection before or after starting treatment with these new drugs.