• When should HBV treatment be started in patients with coinfection?
An ART regimen containing TDF (creatinine clearance > 50 mL/min) or TAF (creatinine clearance > 30 mL/min) with lamivudine or emtricitabine should be used in all HIV/HBV patients as soon as the infection is diagnosed. If TDF or TAF cannot be used, the alternate recommended regimen for HBV is entecavir plus a fully suppressive ART. In those with decreased renal function, entecavir should be adjusted to renal function [19].
Although control of viremia is feasible, clearance of infection as marked by loss of HBsAg and development of anti-HBs is unlikely to occur in the majority of patients. Therefore, the goals of treatment focus on prevention of chronic liver disease complications by suppressing viral replication, which can halt disease progression. A suggested algorithm for the management of coinfected patients is provided (Figure).
• What is the duration of therapy for hepatitis B?
Most patients with HIV/HBV coinfection will require lifelong treatment. All patients on HBV therapy as a part of ART should continue HBV therapy, regardless of seroconversion status. Also, patients should be educated and advised against self-discontinuation as it may trigger hepatitis exacerbations and/or hepatic failure.
Case Patient 3
Initial Presentation and History
Two months after starting treatment for HIV and chronic HBV infection, a 46-year-old Hispanic woman presents to clinic with jaundice and right upper quadrant (RUQ) pain. The patient was recently diagnosed with HIV infection and was naïve to treatment with ART. Her CD4 cell count was 50 cells/µL, and her HIV viral load was 743,000 copies/mL, with no baseline mutations on HIV genotype. The patient was also diagnosed with chronic HBV infection with positive HBsAg and HBeAg and negative HBc IgM serologies, as well as an HBV DNA level of 87 million IU/mL. Routine blood work revealed normal renal function and serum transaminases. The decision was made to start the patient on darunavir/ritonavir and TDF/emtricitabine. The patient was also started on sulfamethoxazole/trimethoprim and azithromycin for opportunistic infection prophylaxis.
Physical Examination and Laboratory Testing
Examination is remarkable for mild tenderness in the RUQ and icteric sclera. Laboratory testing demonstrates the following: AST, 1523 U/L; ALT, 795 U/L; albumin, 2.8 mg/dL; and total bilirubin, 3.5 mg/dL. Her CD4 count has increased to 565 cells/µL, and her HIV viral load is 4320 copies/mL. Results of repeat hepatitis serologies are as follows: HBsAg positive, anti-HBc IgM positive, and an HBV DNA level of 4.2 million IU/mL. Testing for hepatitis A, C, and D is negative, and RUQ sonogram reveals no gallstones.
• What monitoring should be done for coinfected patients on HBV therapy?
Monitoring
Providers should routinely monitor patients’ response to HIV/HBV therapy. Initially, all coinfected patients should have liver function tests and HBV DNA levels checked every 12 weeks on therapy. Frequent monitoring allows early detection of HBV drug resistance as well as drug-related hepatotoxicity. In HBeAg-positive coinfected patients who achieve HBV DNA suppression, HBeAg and anti-HBe testing should be performed every 6 to 12 months to assess for seroconversion. In HBeAg-negative patients, only HBV DNA and liver function tests are needed. HBV virologic failure is defined as a greater than 1-log10 rise in HBV DNA levels or development of viremia in a patient with a previously suppressed DNA level on therapy.
Typically, virologic failure results from either the development of drug resistance or abrupt withdrawal of active HBV therapy due to patient nonadherence or changes to the ART regimen. Virologic failure can result in a rise in serum aminotransferases as well as decompensation in patients with significant underlying liver disease. Due to this risk, providers must counsel patients about the importance of adherence to therapy and should continue medications active against HBV when making a change in ART regimens, unless HBV drug resistance dictates a change in HBV therapy.
• What is the likely cause of this patient’s hepatitis “flare”?
Several studies indicate that patients with HIV/HBV coinfection are at increased risk of drug-related hepatotoxicity and grade 4 liver enzyme elevations [54,55].The first 3 months after initiation of ART is a particularly vulnerable time for liver injury. The differential diagnosis for an acute hepatitis “flare” following the initiation of ART is broad and includes the following: development of HBV drug resistance [16]; withdrawal of HBV-active medications due to nonadherence [54]; ART-related hepatotoxicity; superimposed infection with HAV, HCV, or HDV; other opportunistic infections including cytomegalovirus and mycobacterium avium complex; or IRIS, resulting in an exaggerated cytotoxic response by the recovering immune system [56,57]. Complete evaluation is critical to distinguish between the possible causes.
In this case, several clues point toward HBV-related IRIS as the most likely cause for the hepatitis “flare.” A low pretreatment CD4 cell count with a rapid rise after initiation of ART is associated with a higher rate of IRIS [57]. Serologic testing and imaging excluded superinfection with another hepatotropic virus or biliary tract disease. Appropriate declines in HIV viral load and HBV DNA levels imply patient adherence to therapy and argue against the development of HBV drug resistance. Finally, the emergence of anti-HBc IgM positivity signals HBV reactivation, which is commonly seen in patients with HBV-related IRIS [57]. The preferred treatment for HBV-related IRIS involves continuation of therapy, frequently leading to normalization of aminotransferases and subsequent HBeAg seroconversion. Because IRIS usually manifests within the first 6 to 12 weeks after starting ART, liver enzymes should be monitored closely during this period.
• What health maintenance should be done for coinfected patients?
All patients with HIV/HBV coinfection should be monitored for evidence of portal hypertension or cirrhosis and, if these conditions exist, should undergo endoscopic screening for esophageal varices as well as evaluation of ascites and encephalopathy. Patients with HBV are at increased risk for the development of HCC even in the absence of cirrhosis. A recent study showed low rates of HCC screening in HIV/HBV patients by HIV providers [58]. Whether HIV coinfection potentiates HCC risk is uncertain, though coinfected patients present at younger ages and with more symptoms than HIV-negative comparators [59]. Other risk factors for HCC include HCV infection, alcohol abuse, diabetes, obesity, exposure to environmental toxins, and cirrhosis of any etiology (most commonly non-alcoholic fatty liver disease, primary sclerosing cholangitis, primary biliary cirrhosis and hemochromatosis) [60].