Chemoprophylaxis with isoniazid in liver transplant recipients

Safety and outcome of treatment of latent tuberculosis infection in liver transplant recipients

PURPOSE

Liver transplant (LT) recipients have an increased risk of tuberculosis (TB), which is associated with higher mortality rates. This retrospective cohort study assessed the outcome and tolerability of screening and treatment of latent tuberculosis infection (LTBI) in LT recipients.

METHODS

Between March 2020 and February 2022, all adult LT candidates at our institution were screened for LTBI. The candidates who tested positive for interferon-γ-releasing assay or met epidemiological or clinical-radiological criteria for LTBI were treated and monitored.

RESULTS

Among the 857 LT recipients, 199 (23.2%) were diagnosed with LTBI, of which 171 (85.9%) initiated LTBI treatment. The median duration of follow-up was 677 days. Adequate LTBI treatment occurred in 141/171 (82.5%) patients and was discontinued prematurely in 30/171 (17.5%) patients. The most common reason for discontinuation was liver enzyme elevation (11/30, 36.7%), although only five discontinued treatment due to suspicion of isoniazid-associated hepatotoxicity. None of the LTBI-treated patients developed active TB during the follow-up period, while 3.6% (1/28) of untreated LTBI patients and 0.6% (4/658) of patients without LTBI developed TB.

CONCLUSION

These findings demonstrate that LTBI screening and treatment is a safe and effective strategy to prevent TB in LT recipients. However, monitoring for adverse events and liver enzyme elevation is recommended.

Isoniazid prophylaxis in liver transplant recipient with latent tuberculosis; Is it harmful for transplanted liver?

BACKGROUND

Liver transplantation (LT) is considered the only treatment for patients with end-stage liver disease and, despite its incredible impacts on the patients' health status, places them in an immunocompromised state in which opportunistic infection would find a way to present. Latent Tuberculosis Infection (LTBI) is the most common form of TB and can be diagnosed through Tuberculin Skin Test (TST) or Interferon-Gamma Release Assays (IGRA). LT recipients are at significant risk of TB activation. There is no strict guideline to approaching these cases though, in most centers, Isoniazid (INH) would be prescribed prophylactically. INH is a hepatotoxic medication and can have adverse effects on the transplanted liver. There is no consensus on this issue; therefore, we aimed to survey the potential hepatotoxic effects of INH among LT recipients in Shiraz, Iran.

METHODS

A retrospective cohort study was conducted among LT candidates and recipients at Abu Ali Sina Organ Transplantation Center between 1993 and 2019. All the cases underwent TST and chest X-ray to detect LTBI. All the LTBI were treated with INH from six to nine months and followed by the level of liver enzymes for quick detection of hepatotoxicity. A control group was selected among LT recipients and matched for age, gender, MELD score, and donor age.

RESULTS

Among 4895 medical records reviewed, 55 (1.12%) cases had LTBI. Neither INH-related hepatotoxicity, nor signs and symptoms that were suspicious to TB reactivation were reported. Overall, three deaths were reported, two because of myocardial infarction and one due to pneumonia. Ten patients (18.2%) experienced acute rejection as confirmed with pathology and responded to methylprednisolone. Aspartate aminotransferase (AST) was diminished from pre-LT time to the first time after transplantation; after that, it showed a steady pattern. Meanwhile, Alanine transaminase (ALT) was constant before and one stage later and decreased after that. Statistical analyses only showed significant changes in the total bilirubin titer between the case and control groups.

CONCLUSION

This survey showed prophylactic management of LTBI with INH in LT candidates and recipients was associated with no hepatotoxicity or related death. It seems INH prophylaxis is safe in LT settings and can efficiently prevent TB activation; however, careful monitoring for adverse effects and liver enzymes elevation is highly recommended. This article is protected by copyright. All rights reserved.

Mycobacterial infections in solid organ transplant recipients

Mycobacterium tuberculosis (MTB) infection in solid organ transplant (SOT) recipients remains a major challenge for physicians and surgeons. Active tuberculosis (TB) is associated with increased morbidity and mortality in SOT recipients. MTB usually develops after transplantation in a recipient with latent TB infection (LTBI) before transplantation and may also be transmitted from the donor or acquired from the community. Therefore, screening for LTBI in donors and recipients before transplantation is very important in preventing active disease after transplantation. This review article is based on recently published data, case series, and expert recommendations. We reviewed updated information about the epidemiology, diagnosis, and treatment of latent and active TB before and after transplantation. We also reviewed recent treatments for multidrug-resistant TB.

Latent tuberculosis: Risk factors, screening and treatment in liver transplantation recipients from an endemic area

BACKGROUND

Patients undergoing solid organ transplantation, particularly those who live or have lived in tuberculosis (TB) endemic areas, are at a high risk of developing TB. The majority of post-transplantation TB cases are associated with reactivation of latent TB infection (LTBI). Brazil is in a single position with overlapping areas of high TB endemicity and high transplant activity. In liver transplant (LT), one should be aware of the potential hepatotoxicity associated with the treatment regimens for LTBI.

AIM

To evaluate the frequency of LTBI in LT patients and treatment-related issues.

METHODS

This was a retrospective analysis of a cohort of cirrhotic patients aged ≥ 18 years, who underwent LT at a high-complexity teaching hospital from January 2005 to December 2012.

RESULTS

Overall, 429 patients underwent LT during the study period. Of these, 213 (49.7%) underwent the tuberculin skin test (TST) during the pre-transplant period, and 35 (16.4%) of them had a positive result. The treatment for LTBI was initiated after LT in 12 (34.3%) of the TST-positive patients; in 3 (25.0%), treatment was maintained for at least 6 mo.

CONCLUSION

The prevalence of LTBI was lower than expected. Initiation and completion of LTBI treatment was limited by difficulties in the management of these special patients.

Risk Groups of Developing Active Tuberculosis in Liver Transplant Recipients in a Tuberculosis Endemic Area: Risk Stratification by Chest Image and Interferon Gamma Release Assay

OBJECTIVES

We implemented a stratified risk analysis to predict the development of active tuberculosis (TB) in liver transplantation (LT) recipients based on IGRA and chest images in a TB-endemic area.

METHODS

In this retrospective cohort study, LT recipients who tested for IGRA between May 2008 and December 2017 were included. Chest images compatible with old TB lesions were considered as positive images. LT recipients were divided into six groups: LT recipients with history of treated TB, image (+)/IGRA (+), image (+)/IGRA (-), image (-)/IGRA (+), image (-)/IGRA (-) and LTBI treated. The Cox regression model was used to analyze risk groups.

RESULTS

Among the 717 eligible LT recipients included in this study, 21 patients developed active TB. Incidence rates of TB were 2,261, 724, and 119 cases/100,000 person-years in the 1st, 2nd, and ≥ 3rd year after transplantation, respectively. History of treated TB (HR 18.92; 95% CI 4.10-87.25) and image (+)/IGRA (+) (HR 10.86; 95% CI 2.75-42.89) were independent risk factors for developing active TB. IGRA (+) with a negative image was not a risk factor.

CONCLUSIONS

Our findings suggested that both IGRA and chest images should be considered to identify risk groups for LTBI treatment.

Prevention and treatment of tuberculosis in solid organ transplant recipients

Introduction: Tuberculosis (TB) in solid organ transplant (SOT) recipients is associated with significant morbidity and mortality. Its management in transplant recipients is difficult and highly complex, given the underlying immunosuppression and the risks of drug-drug interactions imposed by immunosuppressive drugs that are needed to maintain the transplant allograft.Areas covered: We provide a brief review of TB in SOT and discuss the clinical indications, mechanisms of action and drug resistance, drug-drug interactions, and adverse effects of anti-TB drugs. We provide a summary of recent clinical trials, which serve as the foundation for current recommendations. We further include relevant updates on new agents being evaluated for clinical use in TB management.Expert commentary: TB causes significant morbidity in SOT recipients. The drugs used in the treatment for latent TB and active disease in SOT are similar to the regimens used in the general population. However, TB disease in transplant recipients is more difficult to manage because of the potential for hepatotoxicity and the complex drug-drug interactions with immunosuppressive drugs. We believe that alternative regimens suited for the vulnerable transplant population, and more therapeutic drug options are needed given the adverse toxicities associated with currently approved anti-TB drugs.

Treatment of latent TB Infection and the risk of tuberculosis after solid organ transplantation: Comprehensive review

BACKGROUND

Mycobacterium tuberculosis disease may occur after treatment of latent TB infection (LTBI). Prompted by a case of reactivation TB disease in a solid organ transplant (SOT) recipient who received LTBI treatment, we reviewed the literature to examine outcomes, adverse effects, resistance, and treatment choices of tuberculosis after LTBI therapy.

METHODS

MEDLINE and Web of Science from inception to 5/2019 were reviewed using key words "latent tuberculosis infection" and "SOT" or "transplantation." The search yielded nine cases, 41 cohort studies and six randomized controlled trials (RCT).

RESULTS

Cohort and RCT demonstrated significant reduction in TB disease among transplanted patients who received LTBI therapy; only 56/2651 (2.1%) SOT patients developed TB after LTBI therapy. Adverse drug reactions occurred in 149/1148 (12.9%) and 73/641 (11.4%) of cohort and RCT patients, respectively. Among liver recipients, 56/266 (21%) developed side effects, of which half (29/56, 51.8%) was INH-related. There was no reported INH resistance.

CONCLUSIONS

Latent TB infection treatment is efficacious in SOT recipients at risk of TB disease. However, tuberculosis may still occur despite LTBI treatment. Hepatotoxicity associated with LTBI therapy is infrequent, although more commonly observed among liver recipients.

Tests for latent tuberculosis in candidates for solid organ transplantation: A systematic review and meta-analysis

Reactivation of latent tuberculosis following solid organ transplantation has serious consequences for the recipient. The most useful diagnostic test for latent TB is not clear. We conducted a systematic review and meta-analysis to assess the relative test performance of interferon gamma release assays (IGRAs) and the tuberculin skin test (TST) in people undergoing solid organ transplantation. The clinical or radiological risk factors were used as the proxy reference standard. Test performance was expressed as an odd ratio (OR). We identified 24 studies (N = 7811), 12 studies compared IGRAs with TST directly, nine studies evaluated only TST and three studies only IGRAs. Direct comparison between tests and clinical risk factors indicated both tests were strongly associated with the presence of clinical risk factors for TB (TST: OR 3.17; 95%CI 1.55-6.48, IGRA: OR 2.78; 95%CI 1.55-5.01), and radiological evidence of past TB (TST: OR 3.26; 95%CI 1.85-5.73, IGRA: OR 3.85; 95%CI 2.16-6.86). Relative comparison indicated IGRAs positivity was more strongly associated with presence of radiological evidence of TB than TST (relative OR: 3.24; 95%CI 1.10-9.56). While there is no strong evidence in supporting use of IGRAs over TST for diagnosing latent TB, IGRAs positivity is more associated with the presence of radiological evidence of previous TB.

Tuberculosis in children presenting with chylothorax - Report of two cases and review of the literature

One third of the world's population is estimated to be infected with Mycobacterium tuberculosis. Tuberculosis (TB) is endemic in many sub-Saharan African counties. The burden is further made worse by the HIV scourge. The number of children with TB and its attendant complications, is equally on the rise. TB can mimic many diseases ranging from infections to malignancies. Among pleuro-pulmonary TB complications, exudative effusion is more common while chylothorax is rare and thus easily missed especially if not the classical milky appearance.

We present two children from a TB endemic region, with microbiologically-confirmed TB presenting with chylothoraces that were initially misdiagnosed as pleural empyema. Tuberculosis in children presenting as chylothorax is uncommon. These cases are instructive as they bring to the fore the importance of a full investigation of pleural effusions in children, to ensure a correct diagnosis and prompt effective management.

A practical approach to tuberculosis diagnosis and treatment in liver transplant recipients in a low-prevalence area

Solid organ transplant candidates/recipients are at risk of mycobacterial infections. Although guidelines on the management of latent tuberculosis infection and active tuberculosis are available for solid organ transplant recipients, limited guidance focuses on end-stage liver disease or liver transplant recipients who require management in a referral center. Therapeutic challenges arise from direct antituberculosis drug-related hepatotoxicity, and substantial metabolic interactions between immunosuppressive and antituberculosis drugs. Another issue is the optimal timing of therapy with regards to the time of transplantation. This review focuses on the importance of tuberculosis screening with immunological tests, challenges in the diagnosis, management, and treatment of latent tuberculosis infection and active tuberculosis, as well as risk assessment for active tuberculosis in the critical peri-liver transplantation period. We detail therapeutic adjustments required for the management of antituberculosis drugs in latent tuberculosis infection and active tuberculosis, particularly when concomitantly using rifampicin and immunosuppressive drugs.

Tuberculosis and Transplantation

Mycobacterium tuberculosis is a major opportunistic pathogen in transplant recipients. Compared to that in the general population, the frequency of tuberculosis (TB) is 10 to 40 times higher in hematopoietic stem cell transplant (HSCT) recipients and 20 to 74 times higher in solid-organ transplant (SOT) recipients. Transplant recipients with TB are also more likely to develop disseminated disease, have longer time to definitive diagnosis, require more invasive diagnostic procedures, and experience greater anti-TB treatment-related toxicity than the general population. Specific risk factors for TB in SOT recipients include previous exposure to M. tuberculosis (positive tuberculin skin tests and/or residual TB lesions in pretransplant chest X ray) and the intensity of immunosuppression (use of antilymphocyte antibodies, type of basal immunosuppression, and intensification of immunosuppressive therapy for allograft rejection). Risk factors in HSCT recipients are allogeneic transplantation from an unrelated donor; chronic graft-versus-host disease treated with corticosteroids; unrelated or mismatched allograft; pretransplant conditioning using total body irradiation, busulfan, or cyclophosphamide; and type and stage of primary hematological disorder. Transplant recipients with evidence of prior exposure to M. tuberculosis should receive treatment appropriate for latent TB infection. Optimal management of active TB disease is particularly challenging due to significant drug interactions between the anti-TB agents and the immunosuppressive therapy. In this chapter, we address the epidemiology, clinical presentation, diagnostic considerations, and management strategies for TB in SOT and HSCT recipients.

Isoniazid Prophylaxis for Latent Tuberculosis Infections in Liver Transplant Recipients in a Tuberculosis-Endemic Area

Background

Isoniazid (INH) prophylaxis (Px) has good efficacy for preventing tuberculosis (TB) in the general population. However, its use for the treatment of latent TB infections (LTBI) in liver transplant (LT) recipients is challenging because little is known about INH-induced hepatotoxicity in graft recipients. We evaluated the efficacy and safety of INH Px in LT recipients.

Material/Methods

From March 2008 to December 2012, we retrospectively reviewed data on 277 patients who received LT at a single center. We examined the results of tuberculin skin tests and interferon-γ release assays, use of INH, INH-induced hepatotoxicity, and post-LT TB occurrence.

Results

Among 277 recipients, 7 cases of post-transplant TB were detected (2.52%). Seventeen patients received post-transplant INH Px. Among INH Px recipients, post-LT TB infection did not occur. Hepatotoxicity after INH Px was significantly lower in the patients who received INH Px at an aspartate aminotransferase (AST) level that was less than 50 U/L than in those who received INH Px at an AST level that was more than 50 U/L (P=0.046, 0.002).

Conclusions

INH is likely to be effective for preventing post-LT TB recurrence in LTBI. However, because of INH-induced hepatotoxicity, it is better to avoid using it in the early post-LT period and to wait to initiate INH Px until liver function is stable in LT recipients.

Globalization of pediatric transplantation: The risk of tuberculosis or not tuberculosis

The risk of TB among pediatric SOT recipients increases as the globalization of medical care continues to broaden. Unlike adults, children and especially infants are more susceptible to TB as a complication after transplantation. Little data exist regarding the true incidence of TB and the optimal risk-based management of this very vulnerable population. Here, we highlight the theoretical and practical issues that complicate the management of these patients and pose some questions that should be addressed when managing these patients. More data are needed to provide optimal guidance of the best diagnostic and management practices to this unique population.

Three months of weekly rifapentine plus isoniazid for latent tuberculosis treatment in solid organ transplant candidates

BACKGROUND

Isoniazid daily for 9 months is the recommended regimen for latent tuberculosis infection (LTBI) in solid organ transplant (SOT) candidates, but its use is controversial, due to reports of hepatotoxicity and low treatment completion rates. A 12-week course of once weekly directly observed therapy (DOT) with isoniazid plus rifapentine (3HP) is a new LTBI treatment regimen. Tolerability and safety data of 3HP LTBI treatment in SOT candidates are limited.

METHODS

Twelve consecutive SOT candidates who underwent DOT with 3HP for LTBI at Westchester Medical Center, Valhalla, New York, USA, between January 2013 and August 2016 were prospectively evaluated for tolerability and safety of 3HP. The diagnosis of LTBI was made in a person with a positive interferon-gamma release test, without a history of previously treated active or latent tuberculosis infection, and without signs, symptoms, or radiographic evidence of active tuberculosis. Patients were followed up 1 month after treatment completion and at routine follow-up visits with their transplant providers.

RESULTS

Eleven patients were men, and the median age was 60 years (range 44-72). Eight patients were liver, and four kidney transplant candidates. The median Model for End-Stage Liver Disease (MELD score) was 17 (range 10-31). All patients completed treatment. Only a single patient developed transaminitis greater than twice the baseline value. Three patients underwent liver transplantation. None of them developed tuberculosis at 9, 22, or 40 months following transplantation.

CONCLUSION

Directly observed 3HP LTBI treatment was not associated with hepatotoxicity, even in patients with higher MELD scores. Further studies are needed to confirm the safety and efficacy of this LTBI treatment regimen in the SOT population.

Mycobacterial infections in solid organ transplant recipients

Mycobacterial infections represent a growing challenge for solid organ transplant recipients (SOT). The adverse effects of tuberculosis (TB) therapy present a major difficulty, due to the interactions with immunosuppressive drugs and direct drug toxicity. While TB may be donor-transmitted or community-acquired, it usually develops at a latent infection site in the recipient. Pre-transplant prevention efforts will improve transplant outcomes and avoid the complications associated with post-transplant diagnosis and treatment. The present review and consensus manuscript is based on the updated published information and expert recommendations. The current data about epidemiology, diagnosis, new regimens for the treatment of latent TB infection (LTBI), the experience with rifamycins for the treatment of active TB in the post-transplant period and the experience with isoniazid for LTBI in the liver transplant population, are also reviewed. We attempt to provide useful recommendations for each transplant period and problem concerning mycobacterial infections in SOT recipients.

Latent tuberculosis in kidney and liver transplant patients: a review of treatment practices and outcomes

BACKGROUND

The standard treatment of latent tuberculosis infection (LTBI) is associated with toxicities and data are limited on tolerability among patients with advanced organ disease listed for transplant. Alternate options are available, but they have yet to be studied in this population.

METHODS

A retrospective review of the treatment of LTBI among kidney and/or liver transplant candidates was conducted to assess factors impacting therapy initiation, tolerability, and completion of therapy.

RESULTS

Of 174 eligible patients, treatment of LTBI was initiated in 129, of which 91 were listed for kidney transplant and 38 were listed for liver or liver/kidney transplant. Infectious Diseases consultation was independently associated with treatment initiation when controlling for waitlisted organ and receipt of hemodialysis (odds ratio [OR] 81.14, 95% confidence interval [CI] 23.94-274.94, P < 0.001). Documented completion of first-line therapy was 47% overall, and 49% and 39%, respectively, among kidney and liver/kidney candidates (P = not significant). On multivariable analysis, controlling for baseline aspartate aminotransferase and waitlisted organ, first-line receipt of rifampin was associated with lower rates of treatment completion (OR 0.19, 95% CI 0.05-0.77, P = 0.02).

CONCLUSION

Based on medical record documentation, completion of first-line therapy was <50% in this cohort, although this is likely an underestimate, as 34% of patients had no chart documentation that therapy was completed. Approximately 20% of patients did not complete first-line therapy because of adverse effects.

Risk factors for hepatotoxicity in solid organ transplants recipients being treated for tuberculosis

BACKGROUND

Tuberculosis (TB) is associated with high morbidity and mortality in solid organ transplant (SOT) recipients. Also, SOT patients have a 20- to 74-fold increase in the chance of developing TB compared to the general population. Here we evaluated the incidence of hepatotoxicity in SOT recipients on treatment for TB and determined risk factors for liver toxicity in these patients.

PATIENTS AND METHODS

Retrospective cohort conducted in a reference hospital for SOT in Southern Brazil. All SOT recipients who underwent TB treatment during the years 2000-2012 were considered for the study.

RESULTS

A total of 69 patients were included in the study and 23 had liver toxicity (incidence 33.3%). Independent risk factors for hepatotoxicity were rifampin use at doses of ≥600 mg daily (P = .016; OR 2.47; 95% CI, 1.18-5.15) and lung transplantation (P = .017; OR 2.05; 95% CI, 1.14-3.70). Kidney transplantation appeared as a protective factor (P = .036; OR 0.50; 95% CI, 0.26-0.96). Mortality was higher in the patients who had hepatotoxicity (43.5%), compared with those who did not (19.6%).

CONCLUSION

In this study, the use of rifampin at doses of 600 mg daily or higher was found to be an independent risk factor for liver toxicity in SOT recipients. The importance of additional risk factors for hepatotoxicity, such as lung transplantation as well as the protective role of kidney transplantation, should be better investigated in SOT recipients being treated for TB.

Outcome of latent tuberculosis infection in solid organ transplant recipients over a 10-year period

BACKGROUND

Screening and therapy of latent tuberculosis infection (LTBI) is recommended in solid organ transplant (SOT). However, there are limited data on the tolerability of LTBI therapy pretransplant and posttransplant. We studied the tolerability of LTBI therapy and effectiveness of a centralized LTBI treatment program in a low-risk population.

METHODS

Provincial TB and transplant databases were retrospectively reviewed for LTBI therapy referrals in SOT candidates and recipients over a 10-year period. Using univariate logistic regression, we examined factors associated with failure to complete therapy and followed patients for active TB.

RESULTS

From 2001 to 2010, 200/461 SOT candidates referred to the TB program (43.4%) were eligible for therapy for LTBI. Eleven patients refused therapy. The remaining patients (n=189) were initially prescribed isoniazid (73%), rifampin (12.7%), or another regimen (14.3%). Adequate LTBI therapy occurred in 122 (64.5%). Patients who were liver transplant candidates or recipients were less likely to complete therapy than nonliver transplant patients (OR, 0.20; P<0.001) as were patients treated in the posttransplant phase (OR, 0.47; P=0.034). Liver enzyme elevation led to discontinuation of therapy more often in liver transplant candidates and recipients (OR, 10.48; P<0.001) and posttransplant treatment (OR, 3.50; P=0.019). In 599.4 patient-years of follow-up posttransplant (mean, 4.9 year/patient), there were no cases of active TB.

CONCLUSION

A centralized referral program for LTBI therapy in transplant candidates is effective to prevent TB reactivation posttransplant. A significant proportion of liver transplant candidates and recipients do not tolerate standard LTBI therapy. Alternative therapies for these patients should be evaluated.

Infections after orthotopic liver transplantation

Opportunistic infections are a leading cause of morbidity and mortality after orthotopic liver transplantation. Systemic immunosuppression renders the liver recipient susceptible to de novo infection with bacteria, viruses and fungi post-transplantation as well to reactivation of pre-existing, latent disease. Pathogens are also transmissible via the donor organ. The time from transplantation and degree of immunosuppression may guide the differential diagnosis of potential infectious agents. However, typical systemic signs and symptoms of infection are often absent or blunted after transplant and a high index of suspicion is needed. Invasive procedures are often required to procure tissue for culture and guide antimicrobial therapy. Antimicrobial prophylaxis reduces the incidence of opportunistic infections and is routinely employed in the care of patients after liver transplant. In this review, we survey common bacterial, fungal, and viral infections after orthotopic liver transplantation and highlight recent developments in their diagnosis and management.

Tuberculosis exposure, infection and disease among children with medical comorbidities

Sixty-nine children with medical comorbidities were treated for tuberculosis (TB) exposure (7), infection (40) or disease (22). The most common comorbidities in children with TB disease were malignancy (23%), cyanotic heart disease (18%), hemoglobinopathies (18%) and autoimmune disease (14%). Ninety-six percent who received TB medications had no adverse events and 98% completed therapy. Two (9%) died of TB.

Hepatotoxicity of antibiotics: a review and update for the clinician

Collectively, the various classes of antibiotics are a leading cause of drug-induced liver injury (DILI). However, acute antibiotic-associated DILI can be difficult to diagnose, as the course of therapy is usually brief, and other confounding factors are often present. In addition to the broad clinicopathologic spectrum of hepatotoxicity associated with the antimicrobials, the underlying infectious disease being treated may itself be associated with hepatic dysfunction and jaundice. This review provides summarized information on several classes of antimicrobial agents, highlighting new agents causing DILI and updating information on older agents.