Hepatitis C virus infection in HIV-infected patients

Challenges in managing HIV in people who use drugs

PURPOSE OF REVIEW

HIV management in people who use drugs (PWUD) is typically complex and challenging due to the presence of multiple medical and psychiatric comorbidities as well as social, physical, economic and legal factors that often disrupt the HIV continuum of care. In this review, we describe the individual, health systems and societal barriers to HIV treatment access and care retention for PWUD. In addition, the clinical management of HIV-infected PWUD is often complicated by the presence of multiple infectious and noninfectious comorbidities.

RECENT FINDINGS

Improved HIV treatment outcomes can be enhanced through improved testing and linkage strategies along with better treatment retention and antiretroviral (ART) adherence. Improved ART adherence can be achieved through the provision of opioid substitution therapy (OST), directly administered ART (DAART) and integration of ART with OST services. Recent advances with direct-acting antivirals (DAAs) for hepatitis C virus (HCV) have shown superior outcomes than interferon-based regimes in HIV-HCV coinfected patients. Newer diagnostic technologies for tuberculosis (TB) hold promise for earlier diagnosis for PWUD coinfected with TB, and TB treatment outcomes are improved through combination with OST.

SUMMARY

HIV-infected PWUDs are a key population who frequently experience suboptimal outcomes along the HIV continuum of care. A comprehensive strategy that encompasses evidence-based prevention and treatment interventions that target the individual, family, healthcare system, legal and societal structure is required to ensure greater participation and success in HIV treatment and care.

The changing epidemiology of HIV-infected patients in the intensive care unit

With the introduction of highly active antiretroviral therapy (HAART), HIV has become a chronic disease. As HIV-infected patients are aging, they are at increased risk for comorbid diseases. These non-AIDS related diseases account for a growing proportion of intensive care unit (ICU) admissions in HIV-infected patients in recent studies. HIV-infected patients still present to the ICU with HIV-related conditions such as Pneumocystis jirovecii pneumonia (PCP), but these conditions are becoming less common. Respiratory failure remains the most common indication for ICU admission. Immune reconstitution inflammatory response syndrome and toxicities related to HAART may also result in ICU admission. While ICU survival has improved since the earliest era of the HIV epidemic, hospital mortality for HIV-infected patients admitted to the ICU remains around 30%. Risk factors for ICU mortality include poor functional status, weight loss, more than one year between HIV diagnosis and ICU admission, lower serum albumin, higher severity of illness, need for mechanical ventilation, and respiratory failure-particularly if due to PCP and accompanied by pneumothorax. The impact of HAART on ICU outcomes is unclear. HAART administration in the ICU can be challenging due to limited delivery routes, concern for viral resistance and medication toxicities. There are no data to determine the safety or efficacy of HAART initiation in the ICU. Future studies are needed to address the role of age, associated comorbidities and impact of HAART on outcomes of HIV-infected patients admitted to the ICU.

Infectious disease comorbidities adversely affecting substance users with HIV: hepatitis C and tuberculosis

The linkage between drug use, particularly injection drug use, and HIV/AIDS, hepatitis C (HCV), and tuberculosis (TB) has been recognized since the beginning of the HIV pandemic. These comorbid conditions affect drug users worldwide and act synergistically, with resultant adverse biologic, epidemiologic, and clinical consequences. Prevention, care, and treatment of TB and HCV can be successful, and both diseases can be cured. Special clinical challenges among drug users, however, can result in increased morbidity, mortality, and decreased therapeutic success. Among these are limited disease screening, inadequate and insensitive diagnostics, difficult treatment regimens with varying toxicities, and complicated pharmacokinetic and pharmacodynamic drug interactions. These may result in delayed diagnosis, deferred treatment initiation, and low completion rates, with the potential for generation and transmission of drug resistant organisms. Strategies to address these challenges include outreach programs to engage substance abusers in nonmedical settings, such as prisons and the streets, active screening programs for HIV, HCV, and TB, increased and broadened clinician expertise, knowledge and avoidance of drug interactions, attention to infection control, use of isoniazid preventive therapy, and creative strategies to insure medication adherence. All of these require structural changes directed at comprehensive prevention and treatment programs and increased collaboration and integration of needed services for substance abusers.

Spontaneous clearance of hepatitis C virus after liver transplantation in two patients coinfected with hepatitis C virus and human immunodeficiency virus

Spontaneous resolution of chronic hepatitis C virus (HCV) infection is exceedingly rare and poorly understood. As HCV and human immunodeficiency virus (HIV) have shared routes of transmission, HCV coinfection is estimated to affect 15%-30% of the HIV-positive population. We report 2 patients with HCV-HIV coinfection who underwent orthotopic liver transplantation at our center and had spontaneous clearance of their chronic HCV infection after transplantation without any anti-HCV treatment. Both patients showed no evidence of HCV recurrence for more than 3 years despite long-term immunosuppressant therapy. Spontaneous clearance of chronic HCV infection can occur in HIV-HCV-coinfected patients after liver transplantation. The mechanism of this phenomenon remains unclear.

Prevalence of coinfection with human immunodeficiency virus and hepatitis C virus in Japan

People with human immunodeficiency virus (HIV) infection are frequently infected with hepatitis C virus (HCV), because of the common transmission routes. Since the dissemination of hyperactive antiretrovirus therapy (HAART), the morbidity and mortality associated with HIV infection have declined. However, the reduction in mortality due to opportunistic infection has made HCV-associated liver diseases the leading cause of mortality in Western countries. A similar situation is assumed in Japan, but the status of coinfection with HIV and HCV is unclear. We conducted a nationwide survey to determine the prevalence of coinfection with HIV and HCV by distributing a questionnaire to the hospitals in the HIV/AIDS Network of Japan. Among 4877 patients reported to be HIV-positive, 935 (19.2%) were also positive for the anti-HCV antibody. Most (84.1%) of the patients coinfected with HIV and HCV were recipients of blood products. These data, for the first time, show the current status of coinfection with HIV and HCV in Japan. A detailed analysis of the progression and severity of liver diseases in the coinfected patients is expected.

Treatment of hepatitis C infection

HCV infection is one of the leading causes of chronic liver disease worldwide,and it results in cirrhosis, liver failure, and HCC. As a result, hepatitis C cirrhosis has become the principal indication for liver transplantation. Ironically,HCV infection can be cured with available antiviral therapies, but only a minority of infected persons has ever been treated. The current standard of therapy isa combination of PEG-IFNalpha and ribavirin, which produces high rates of SVRs(absence of detectable HCV RNA at least 24 weeks after cessation of therapy):42% to 56% in genotype 1 and 75% to 84% in genotypes 2 and 3. Recent reports indicate that the less frequent genotypes 4, 5, and 6 also are responsive to combination therapy. Recommendations for treatment of conventional and special patient populations were reviewed in detail. Newer therapeutics that are entering clinical trials provide hope that SVRs may be possible in patients who are difficult to treat and in nonresponders to current therapy.