When Liver Disease Causes HIV

Abstract

Introduction: In the U.S., about 30% of HIV patients are co-infected with hepatitis C virus (HCV). The high rate of co-infection is largely due to similar routes of transmission. Sequence of infection varies by transmission route based on the efficiency of transmission. Injection drug users usually acquire HCV before HIV because HCV is so efficiently transmitted percutaneously. Alternatively, men who have sex with men are typically infected with HIV first. Due to their similar risk factors, patients with either virus should be screened for the other. Case history: 34 year old male with a history of intravenous drug use and hepatitis C infection presents to the emergency department (ED) with arm pain for 5 days. Patient stated that one week prior to admission, he had a relapse and injected heroin in his right antecubital fossa. Two days later, patient noticed redness on his right arm associated with pain, bringing him to the ED. Since then, pain worsened and became so severe that he felt he could not flex or extend his upper extremity at the elbow. Denied fevers, chills, rashes, nausea, vomiting, diarrhea, constipation, chest pain, shortness of breath, abdominal pain, urinary symptoms. Patient was admitted for treatment of abscess with overlying cellulitis with incision and drainage as well as intravenous vancomycin. Due to patient's high-risk behaviors, HIV rapid testing was sent. Screening test was resulted as positive. Confirmatory testing was done with HIV-1/HIV-2 antibody differentiation. The result of this test was negative. HIV viral load was then checked which was also negative. Discussion: False negative results for anti-HCV tests have been reported in HIV infected patients. Recommendations exist to additionally check for viral load as a confirmatory test in these patients. However, false positive HIV results in hepatitis C patients has been less well-documented. Because hepatitis C is generally asymptomatic for a long period of time, diagnosis is made later compared to HIV where patients can become acutely symptomatic. Given new recommendations to increase screening for hepatitis C virus in asymptomatic patients of a certain age, hepatitis C diagnosis will start to be made earlier. All patients with hepatitis C should also be screened for HIV given their similar risk factors and routes of transmission. The possibility of false positive results raises the question of appropriate tests for screening in this population.