Hepatic involvement with tuberculosis-associated immune reconstitution disease

Integrated therapy for HIV and tuberculosis

Tuberculosis (TB) has been the most common opportunistic infection and cause of mortality among HIV-infected patients, especially in resource-limited countries. Clinical manifestations of TB vary and depend on the degree of immunodeficiency. Sputum microscopy and culture with drug-susceptibility testing are recommended as a standard method for diagnosing active TB. TB-related mortality in HIV-infected patients is high especially during the first few months of treatment. Integrated therapy of both HIV and TB is feasible and efficient to control the diseases and yield better survival. Randomized clinical trials have shown that early initiation of antiretroviral therapy (ART) improves survival of HIV-infected patients with TB. A delay in initiating ART is common among patients referred from TB to HIV separate clinics and this delay may be associated with increased mortality risk. Integration of care for both HIV and TB using a single facility and a single healthcare provider to deliver care for both diseases is a successful model. For TB treatment, HIV-infected patients should receive at least the same regimens and duration of TB treatment as HIV-uninfected patients. Currently, a 2-month initial intensive phase of isoniazid, rifampin, pyrazinamide, and ethambutol, followed by 4 months of continuation phase of isoniazid and rifampin is considered as the standard treatment of drug-susceptible TB. ART should be initiated in all HIV-infected patients with TB, irrespective of CD4 cell count. The optimal timing to initiate ART is within the first 8 weeks of starting antituberculous treatment and within the first 2 weeks for patients who have CD4 cell counts <50 cells/mm(3). Non-nucleoside reverse transcriptase inhibitor (NNRTI)-based ART remains a first-line regimen for HIV-infected patients with TB in resource-limited settings. Although a standard dose of both efavirenz and nevirapine can be used, efavirenz is preferred because of more favorable treatment outcomes. In the settings where raltegravir is accessible, doubling the dose to 800 mg twice daily is recommended. Adverse reactions to either antituberculous or antiretroviral drugs, as well as immune reconstitution inflammatory syndrome, are common in patients receiving integrated therapy. Early recognition and appropriate management of these consequences can reinforce the successful integrated therapy in HIV-infected patients with TB.

Efficacy and Safety of Antiretroviral Therapy Initiated One Week after Tuberculosis Therapy in Patients with CD4 Counts < 200 Cells/μL: TB-HAART Study, a Randomized Clinical Trial

Background

Given the high death rate the first two months of tuberculosis (TB) therapy in HIV patients, it is critical defining the optimal time to initiate combination antiretroviral therapy (cART).

Methods

A randomized, open-label, clinical trial comparing efficacy and safety of efavirenz-based cART initiated one week, four weeks, and eight weeks after TB therapy in patients with baseline CD4 count < 200 cells/μL was conducted. The primary endpoint was all-cause mortality rate at 48 weeks. The secondary endpoints were hepatotoxicity-requiring interruption of TB therapy, TB-associated immune reconstitution inflammatory syndrome, new AIDS defining illnesses, CD4 counts, HIV RNA levels, and AFB smear conversion rates. All analyses were intention-to-treat.

Results

We studied 478 patients with median CD4 count of 73 cells/μL and 5.2 logs HIV RNA randomized to week one (n = 163), week four (n = 160), and week eight (n = 155). Sixty-four deaths (13.4%) occurred in 339.2 person-years. All-cause mortality rates at 48 weeks were 25 per 100 person-years in week one, 18 per 100 person-years in week four and 15 per 100 person-years in week eight (P = 0.2 by the log-rank test). All-cause mortality incidence rate ratios in subgroups with CD4 count below 50 cells/μL versus above were 2.8 in week one (95% CI 1.2–6.7), 3.1 in week four (95% CI 1.2–8.6) and 5.1 in week eight (95% CI 1.8–16). Serum albumin < 3gms/dL (adjusted HR, aHR = 2.3) and CD4 < 50 cells/μL (aHR = 2.7) were independent predictors of mortality. Compared with similar subgroups from weeks four and eight, first-line TB treatment interruption was high in week one deaths (P = 0.03) and in the CD4 subgroup <50 cells/μL (P = 0.02).

Conclusions

Antiretroviral therapy one week after TB therapy doesn’t improve overall survival. Despite increased mortality with CD4 < 50 cells/μL, we recommend cART later than the first week of TB therapy to avoid serious hepatotoxicity and treatment interruption.

Trial Registration

ClinicalTrials.gov NCT 01315301

Management of the immune reconstitution inflammatory syndrome

The immune reconstitution inflammatory syndrome (IRIS) is a frequent early complication of antiretroviral therapy (ART) in patients with advanced HIV. Because there is no confirmatory diagnostic test, the diagnosis is based on clinical presentation and exclusion of alternative causes for deterioration, such as antimicrobial drug resistance. Opportunistic infection treatment should be optimized. Mild cases may require symptomatic therapy alone or nonsteroidal anti-inflammatory drugs. Corticosteroids have been used to treat more severe cases of IRIS associated with mycobacterial and fungal infections. There is evidence from a randomized controlled trial that prednisone reduces morbidity and improves symptoms in paradoxical tuberculosis (TB)-IRIS. Neurological TB-IRIS is potentially life-threatening; high-dose corticosteroids are indicated and ART interruption should be considered if level of consciousness is depressed. When considering corticosteroid treatment clinicians should be aware of their side effects and only use them when the diagnosis of IRIS is certain. In viral forms of IRIS corticosteroids are generally avoided.

Clinicopathological correlates in HIV seropositive tuberculosis cases presenting with jaundice after initiating antiretroviral therapy with a structured review of the literature

Background

The development of jaundice after initiation of HAART in HIV-TB co-infected patients is a challenging presentation in resource constrained settings, and is often attributed to drug induced liver injury (DILI).Some investigators have described hepatic tuberculosis Immune Reconstitution Inflammatory Syndrome (TB-IRIS) as a cause of liver disease in patients initiating HAART, which could also cause jaundice.

Case presentations

We report the clinical and histopathological features of five HIV-TB co-infected patients presenting with a syndrome of jaundice, tender hepatomegaly, bile canalicular enzyme rise and return of constitutional symptoms within 8 weeks of initiation of highly active antiretroviral therapy (HAART) for advanced HIV infection at a rural clinic in KwaZulu Natal, South Africa.

All five patients had been diagnosed with tuberculosis infection prior to HAART initiation and were on antituberculous medication at time of developing jaundice. There was evidence of multiple aetiologies of liver injury in all patients. However, based on clinical course and pathological findings, predominant hepatic injury was thought to be drug induced in one case and hepatic tuberculosis associated immune reconstitution inflammatory syndrome (TB-IRIS) in the other four.

In these later 4 patients, liver biopsy findings included necrotising and non-necrotising granulomatous inflammation in the lobules and portal tracts. The granulomas demonstrated – in addition to epithelioid histiocytes and Langhans giant cells – neutrophils, plasma cells and large numbers of lymphocytes, which are not features of a conventional untreated tuberculous response.

Conclusion

In this high TB prevalent, low resource setting, TB-IRIS may be an important cause of jaundice post-HAART initiation. Clinicopathological correlation is essential for optimal diagnosis. Further multi-organ based histopathological studies in the context of immune reconstitution would be useful to clinicians in low resource settings dealing with this challenging presentation.

Incidence and risk factors of serious adverse events during antituberculous treatment in Rwanda: a prospective cohort study

Background

Tuberculosis (TB) and TB-human immunodeficiency virus infection (HIV) coinfection is a major public health concern in resource-limited settings. Although TB treatment is challenging in HIV-infected patients because of treatment interactions, immunopathological reactions, and concurrent infections, few prospective studies have addressed this in sub-Saharan Africa.

In this study we aimed to determine incidence, causes of, and risk factors for serious adverse events among patients on first-line antituberculous treatment, as well as its impact on antituberculous treatment outcome.

Methods and findings

Prospective observational cohort study of adults treated for TB at the Internal Medicine department of the Kigali University Hospital from May 2008 through August 2009.

Of 263 patients enrolled, 253 were retained for analysis: median age 35 (Interquartile range, IQR 28–40), 55% male, 66% HIV-positive with a median CD4 count 104 cells/mm³ (IQR 44–248 cells/mm³). Forty percent had pulmonary TB, 43% extrapulmonary TB and 17% a mixed form. Sixty-four (26%) developed a serious adverse event; 58/167 (35%) HIV-infected vs. 6/86 (7%) HIV-uninfected individuals. Commonest events were concurrent infection (n = 32), drug-induced hepatitis (n = 24) and paradoxical reactions/TB-IRIS (n = 23).

HIV-infection (adjusted Hazard Ratio, aHR 3.4, 95% Confidence Interval, CI 1.4–8.7) and extrapulmonary TB (aHR 2, 95%CI 1.1–3.7) were associated with an increased risk of serious adverse events. For TB/HIV co-infected patients, extrapulmonary TB (aHR 2.0, 95%CI 1.1–3.9) and CD4 count <100 cells/mm3 at TB diagnosis (aHR 1.7, 95%CI 1.0–2.9) were independent predictors. Adverse events were associated with an almost two-fold higher risk of unsuccessful treatment outcome at 6 months (HR 1.89, 95%CI 1.3–3.0).

Conclusion

Adverse events frequently complicate the course of antituberculous treatment and worsen treatment outcome, particularly in patients with extrapulmonary TB and advanced immunodeficiency. Concurrent infection accounts for most events. Our data suggest that deterioration in a patient already receiving antituberculous treatment should prompt an aggressive search for additional infections.

Tuberculosis-associated immune reconstitution inflammatory syndrome and unmasking of tuberculosis by antiretroviral therapy

The tuberculosis-associated immune reconstitution inflammatory syndrome (TB-IRIS) is a frequent early complication of antiretroviral therapy (ART), used to treat HIV-1 infection, especially in countries where TB is prevalent. TB-IRIS is characterized by an exaggerated inflammatory response toward the antigens of Mycobacterium tuberculosis that results in clinical deterioration in patients experiencing immune recovery during early ART. Two forms of TB-IRIS are recognized: paradoxical; and unmasking. Paradoxical TB-IRIS manifests with new or recurrent TB symptoms or signs in patients being treated for TB during early ART, and unmasking TB-IRIS is characterized by an exaggerated, unusually inflammatory initial presentation of TB during early ART. In this review the incidence, clinical features, risk factors, treatment, and prevention of TB-IRIS in adult and pediatric patients are discussed.

Validation of a published case definition for tuberculosis-associated immune reconstitution inflammatory syndrome

OBJECTIVE

To evaluate the International Network for the Study of HIV-associated IRIS (INSHI) case definitions for tuberculosis (TB)-associated immune reconstitution inflammatory syndrome (IRIS) in a South African cohort.

METHODS

Prospective cohort of 498 adult HIV-infected patients initiating antiretroviral therapy. Patients were followed up for 24 weeks and all clinical events were recorded. Events with TB-IRIS as possible cause were assessed by consensus expert opinion and INSHI case definition. Positive, negative, and chance-corrected agreement (kappa) were calculated, and reasons for disagreement were assessed.

RESULTS

One hundred and two (20%) patients were receiving TB therapy at antiretroviral therapy initiation. Three hundred and thirty-three events were evaluated (74 potential paradoxical IRIS, 259 potential unmasking IRIS). Based on expert opinion, there were 18 cases of paradoxical IRIS associated with TB and/or other opportunistic disease. The INSHI criteria for TB-IRIS agreed in 13 paradoxical cases, giving positive agreement of 72.2%, negative agreement in 52/56 non-TB-IRIS events (92.9%), and kappa of 0.66. There were 19 unmasking TB-IRIS cases based on expert opinion, of which 12 were considered IRIS using the INSHI definition (positive agreement 63.2%). There was agreement in all 240 non-TB-IRIS events (negative agreement 100%) and kappa was 0.76.

CONCLUSION

There was good agreement between the INSHI case definition for both paradoxical and unmasking TB-IRIS and consensus expert opinion. These results support the use of this definition in clinical and research practice, with minor caveats in its application.

Management of individuals requiring antiretroviral therapy and TB treatment

PURPOSE OF REVIEW

Globally, tuberculosis (TB) is the commonest opportunistic infection in people living with HIV. Many co-infected patients first present with advanced immunosuppression and require antiretroviral therapy (ART) initiation during TB treatment. The incidence of TB in patients established on ART remains high. Co-treatment presents several management challenges. Recent data on these management issues are reviewed.

RECENT FINDINGS

Efavirenz concentrations at standard doses are similar with and without concomitant rifampicin-based TB treatment. Nevirapine concentrations are frequently subtherapeutic during lead-in dosing at 200 mg daily in patients on rifampicin-based TB treatment, which may result in inferior virological outcomes. Hepatotoxicity occurred in three pharmacokinetic studies (conducted in healthy volunteers) of boosted protease inhibitors initiated in participants on rifampicin. Results of a clinical trial comparing efavirenz-based and nevirapine-based ART in patients on TB treatment, with no lead-in dosing of nevirapine, are awaited. Concurrent TB treatment increases the need for stavudine substitutions, mainly related to neuropathy. Consensus case definitions for TB immune reconstitution inflammatory syndrome (TB-IRIS) have been published. It is important to exclude TB drug resistance in patients with suspected TB-IRIS. A clinical trial demonstrated benefit of prednisone for treating TB-IRIS, reducing a combined endpoint of days of hospitalization and outpatient therapeutic procedures. Starting ART during TB treatment improved survival in patients with CD4 cell count less than 500 cells/mul, but the optimal interval between starting TB treatment and starting ART remains to be determined in several ongoing trials.

SUMMARY

ART improves survival in co-infected TB patients, but is complicated by several management challenges that compromise programmatic implementation in resource-limited settings. Recent findings and the findings of ongoing studies will assist clinicians in dealing with these challenges.

Novel relationship between tuberculosis immune reconstitution inflammatory syndrome and antitubercular drug resistance

BACKGROUND

Tuberculosis (TB) immune reconstitution inflammatory syndrome (IRIS) is emerging as an important early complication of combination antiretroviral therapy in patients with TB in developing countries. The differential diagnosis of TB IRIS includes deterioration caused by other human immunodeficiency virus-related morbidities and drug-resistant TB.

METHODS

We prospectively evaluated consecutive patients with suspected TB IRIS from February 2005 through July 2006 at a community-based secondary hospital in Cape Town, South Africa, by means of clinical case definitions for TB IRIS. Specimens were sent for TB culture and susceptibility testing, and a rapid test (FASTplaque-Response) was performed to expedite determination of rifampin susceptibility.

RESULTS

One hundred patients with suspected TB IRIS were evaluated, 26 of whom were being retreated for TB. IRIS symptoms developed a median of 14 days (interquartile range, 7-25 days) after the initiation of combination antiretroviral therapy. In 7 patients, an alternative opportunistic disease was diagnosed. Rifampin-resistant TB was present in 13 patients, 9 of whom received a diagnosis after study entry (7 of 9 had multidrug-resistant TB). Undiagnosed rifampin-resistant TB was thus present in 10.1% of patients (95% confidence interval, 3.9%-16.4%) who presented with TB IRIS, once those with alternative diagnoses and TB with known rifampin resistance were excluded. In the remaining 80 patients, TB IRIS without rifampin resistance was the final diagnosis.

CONCLUSIONS

TB IRIS that is clinically indistinguishable from TB IRIS that occurs in the context of drug-susceptible disease may occur in patients with undiagnosed multidrug-resistant TB. Antitubercular drug resistance should be excluded in all cases of suspected TB IRIS, and corticosteroids should be used with caution for patients with presumed TB IRIS until the result of drug-susceptibility testing is known.

Immune reconstitution disease associated with mycobacterial infections

PURPOSE OF REVIEW

We review immune reconstitution disease associated with mycobacterial infections in patients receiving antiretroviral treatment. We draw particular attention to data relevant to resource-limited settings and focus predominantly on publications over the past year.

RECENT FINDINGS

Worldwide mycobacteria are the most important group of pathogens associated with immune reconstitution disease. In cohorts of patients with tuberculosis in high-income countries, up to one-third develop immune reconstitution disease compared with only 8-13% in current reports from resource-limited settings. We speculate on potential explanations for this difference. While most cases of tuberculosis immune reconstitution disease are self-limiting, deaths have been reported in South African and Thai cohorts. We discuss how risk and outcomes of tuberculosis immune reconstitution disease represent key variables regarding the optimum time to initiate antiretroviral treatment in tuberculosis patients. A new conceptual framework has been proposed regarding 'unmasking' of tuberculosis during antiretroviral treatment. Increasing numbers of cases of leprosy immune reconstitution disease and Bacillus Calmette-Guérin immune reconstitution disease have also been reported, mainly from resource-limited settings. Immune reconstitution disease associated with a variety of mycobacteria (tuberculous and nontuberculous) was common in a cohort of Thai children.

SUMMARY

Immune reconstitution disease associated with a range of mycobacteria constitutes a challenge to delivery of antiretroviral treatment worldwide. Data concerning the pathogenesis and management of all forms of mycobacterial immune reconstitution disease are lacking.