Management of tuberculosis in the transplant recipient

Drug Metabolism, Drug Interactions, and Drug-Induced Liver Injury in Living Donor Liver Transplant Patients

Living donor liver transplant (LDLT) fills a critically needed gap in the number of livers available for transplant. However, little is known about the functional recovery of the liver in the donor and in the recipient after surgery. Given that both donor and recipients are treated with several drugs, it is important to characterize the time course of recovery of hepatic synthetic, metabolic, and excretory function in these patients. In the absence of data from LDLT, information on the effect of liver disease on the pharmacokinetics of medications can be used as guidance for drug dosing in LDLT patients.

Clinical features and outcomes of tuberculosis in transplant recipients as compared with the general population: a retrospective matched cohort study

There are no previous studies comparing tuberculosis in transplant recipients (TRs) with other hosts. We compared the characteristics and outcomes of tuberculosis in TRs and patients from the general population. Twenty-two TRs who developed tuberculosis from 1996 through 2010 at a tertiary hospital were included. Each TR was matched by age, gender and year of diagnosis with four controls selected from among non-TR non-human immunodeficiency virus patients with tuberculosis. TRs (21 patients, 96%) had more factors predisposing to tuberculosis than non-TRs (33, 38%) (p <0.001). Pulmonary tuberculosis was more common in non-TRs (77 (88%) vs. 12 TRs (55%); p 0.001); disseminated tuberculosis was more frequent in TRs (five (23%) vs. four non-TRs (5%); p 0.005). Time from clinical suspicion of tuberculosis to definitive diagnosis was longer in TRs (median of 14 days) than in non-TRs (median of 0 days) (p <0.001), and invasive procedures were more often required (12 (55%) TRs and 15 (17%) non-TRs, respectively; p 0.001). Tuberculosis was diagnosed post-mortem in three TRs (14%) and in no non-TRs (p <0.001). Rates of toxicity associated with antituberculous therapy were 38% in TRs (six patients) and 10% (seven patients) in non-TRs (p 0.014). Tuberculosis-related mortality rates in TRs and non-TRs were 18% and 6%, respectively (p 0.057). The adjusted Cox regression analysis showed that the only predictor of tuberculosis-related mortality was a higher number of organs with tuberculosis involvement (adjusted hazard ratio 8.6; 95% CI 1.2-63). In conclusion, manifestations of tuberculosis in TRs differ from those in normal hosts. Post-transplant tuberculosis resists timely diagnosis, and is associated with a higher risk of death before a diagnosis can be made.

Drug-drug interactions with oral anti-HCV agents and idiosyncratic hepatotoxicity in the liver transplant setting

Studies of boceprevir and telaprevir based antiviral therapy in liver transplant (LT) recipients with hepatitis C genotype 1 infection have demonstrated dramatic increases in tacrolimus, cyclosporine, and mTOR inhibitor exposure. In addition to empiric dose reductions, daily monitoring of immunosuppressant blood levels is required when initiating as well as discontinuing the protease inhibitors to maximize patient safety. Although improved suppression of HCV replication is anticipated, 20 to 40% of treated subjects have required early treatment discontinuation due to various adverse events including anemia (100%), infection (30%), nephrotoxicity (20%) and rejection (5 to 10%). Simeprevir and faldaprevir will likely have improved efficacy and safety profiles but potential drug interactions with other OATP1B1 substrates and unconjugated hyperbilirubinemia are expected. In contrast, sofosbuvir and daclatasvir based antiviral therapy are not expected to lead to clinically significant drug-drug interactions in LT recipients but confirmatory studies are needed. Liver transplant recipients may also be at increased risk of developing drug induced liver injury (DILI). Establishing a diagnosis of DILI in the transplant setting is very difficult with the variable latency, laboratory features and histopathological manifestations of hepatotoxicity associated with a given drug, the need to exclude competing causes of allograft injury, and the lack of an objective and verifiable confirmatory test. Nonetheless, a heightened awareness of the possibility of DILI is warranted in light of the large number of medications used in LT recipients and the potential adverse impact that DILI may have on patient outcomes.

Detection and management of latent tuberculosis in liver transplant patients

The optimal means for detecting and managing liver transplantation (LT) patients with latent tuberculosis (TB) are not well defined. Our study aims were to (1) determine the frequency and risk factors of latent TB in a large cohort of consecutive adult LT candidates and (2) determine the safety and efficacy of isoniazid treatment in LT recipients with latent TB. A review of patients assessed for latent TB by skin testing using purified protein derivative (PPD; January 2004 to September 2008) or with the interferon-γ release assay QuantiFERON-TB Gold (QFT; March 2008 to October 2009) was undertaken. The baseline clinical features and outcomes of subjects with latent TB and subjects without latent TB were compared. Twenty-five of 420 subjects (6.0%) were positive for PPD. In comparison, 11 of 119 subjects (9.2%) had a positive QFT assay, and 15 others (13%) had indeterminate results. Both PPD-positive and QFT-positive subjects were less likely to be Caucasian than subjects without latent TB (p < 0.001). The 3-year survival rate of the 25 LT recipients with latent TB was similar to that of the 296 LT recipients without latent TB (78.7% versus 74.6%, P = 0.58). Fifteen of the 25 latent TB patients received isoniazid at a mean of 0.67 months after LT. Although isoniazid was discontinued in 8 subjects because of possible side effects, none of the 25 latent TB patients developed TB reactivation after transplantation with a mean follow-up of 33 months. In conclusion, both QFT testing and PPD testing demonstrate similar rates of detecting latent TB infection in American LT candidates, but QFT testing also leads to a moderate rate of indeterminate test results. Early isoniazid chemoprophylaxis after LT is poorly tolerated and is frequently discontinued.

Solitary pulmonary nodule in the liver transplant candidate: importance of diagnosis and treatment

Our objectives were to define the incidence and etiology of solitary pulmonary nodules (SPNs) in patients undergoing living donor liver transplantation (LDLT), describe a diagnostic approach to the management of SPNs in LDLT, and define the impact of SPNs on the overall survival of adult LDLT recipients. Nine patients (9/152, 5.9%) were diagnosed with an SPN on the basis of chest radiography findings during the pretransplant survey. All were male. The mean age was 52 years. All the patients had hepatitis B virus-related cirrhosis with hepatocellular carcinoma. All were asymptomatic for the lung lesion. All underwent contrast-enhanced chest computed tomography (CT) to verify the presence and possible etiology of the SPNs. In 3 cases, CT was used to definitely determine that there was no pulmonary nodule; in 2, CT led to a definite diagnosis of pulmonary tuberculosis. In 4, CT led to a definite identification of an SPN but not to an etiological diagnosis. Two patients underwent outright thoracoscopy and biopsy of their SPNs. Biopsy showed cryptococcosis in both patients. One received a therapeutic trial of an antituberculosis treatment, and repeat CT after 1 month showed a regression in the size of the SPN. A diagnosis of tuberculosis was made. One patient had an inconclusive whole body positron emission tomography scan and subsequently underwent thoracoscopy where biopsy showed tuberculosis. A concomitant malignancy, either primary lung cancer or metastasis from the liver tumor, was not identified. All patients were surviving with their original grafts and were lung infection-free. The overall mean posttransplant follow-up was 54 months (range = 33-96 months).

Safety of Treatment of Latent Tuberculosis Infection in Compensated Cirrhotic Patients During Transplant Candidacy Period

BACKGROUND

Treatment of latent tuberculosis infection with isoniazid (INH) or rifampin (RIF) is controversial in liver transplant candidates due to potential hepatotoxicity. In this study, treatment of latent tuberculosis during transplant candidacy period is explored, and relevant literature is reviewed.

METHODS

Liver transplant candidates with latent tuberculosis infection by positive tuberculin skin test (>5 mm) were prospectively enrolled and treated with 9 months of INH or 4 months of RIF, and were monitored monthly for their liver enzyme profiles, adverse effects, compliance, and completion rate.

RESULTS

Four of nine patients with INH had asymptomatic, mild elevations of aspartate aminotransferase (AST) or alanine aminotransferase (ALT) versus none of five patients in the RIF group. Two cases of elevations were attributed to INH. Two other cases were attributed to alcoholism or active chronic hepatitis B virus infection. Only one patient in the INH group experienced symptoms possibly attributed to INH hepatotoxicity. Compliance was 100% per patient reporting. Completion rates were 79% for INH and 100% for RIF. No fulminant hepatic failure or death was observed.

CONCLUSION

Treatment of latent tuberculosis in liver transplant patients during their candidacy with INH or RIF appears to be a safe, viable option, if carefully monitored for adverse effects and liver enzymes.

Antituberculous therapy-induced fulminant hepatic failure: successful treatment with liver transplantation and nonstandard antituberculous therapy

Standard antituberculous therapy including isoniazid, rifampin, ethambutol, and pyrazinamide is widely used for the treatment of active tuberculosis. Its most important side effect is hepatotoxicity, ranging from asymptomatic transaminitis to fulminant hepatic failure. A 19-year-old woman was admitted to our unit due to jaundice and unconsciousness. According to her past medical history, she was diagnosed as having extrapulmonary tuberculosis and had been prescribed standard antituberculous therapy. The patient became icteric and unconscious on the fourth day after therapy initiation. She was diagnosed with drug-induced acute fulminant hepatic failure and underwent living-related liver transplantation. Nonhepatotoxic antituberculous therapy (cycloserine, ciprofloxacin, streptomycin, and ethambutol) and low-dose immunosuppressive therapy were started after transplantation. Currently the patient is very well with normal graft function 42 months after transplantation. Here we report a case of a patient with acute fulminant hepatic failure caused by isoniazid, rifampicin, or both, who was successfully treated with living-related liver transplantation and a relatively less hepatotoxic antituberculous therapy. In conclusion, liver transplantation is a feasible therapy for individuals with standard antituberculous therapy-induced hepatic failure. Nonhepatotoxic antituberculous therapy may achieve control of active tuberculosis in such individuals after transplantation.