focused on positive.50,52 non-Asian patients with HBeAg- Diagnosis Hepatitis B virus is a dynamic virus and its co- infection with HIV makes the diagnosis process sig- nificantly difficult. However, proper diagnosis and monitoring of co-infection of hepatitis B and HIV, along with complete understanding of the mecha- nisms of drug resistance, will allow researchers and clinicians to manage co-infection cases more effi- ciently. In general, there is a series of actions for the diagnosis or even prevention of co-infections which are mostly recommended to be accomplished in cases of new HIV infections. First, all individuals diag- nosed with HIV recently, should be examined for hepatitis B surface antigen (HBsAg) and anti-HBs. Positive HBsAg expresses HBV co-infection. For HBsAg positive patients, HBeAg, anti-HBe and HBV DNA should be tested, otherwise it is recommended to apply HBV vaccination. In addition to a complete history and physical examinations, newly HIV infect- ed patients’ bloods should be screened for complete blood pictures, clotting profiles including prothrom- bin time, international normalized ratio (INR), alpha- fetoprotein (AFP) and tests on liver and renal func- tions. Performing a baseline hepatic ultrasound is the next step.46 Finally, to screen the condition of the liver, it is highly recommended to assess fibrosis using liver biopsy in individuals suspicious of having HBV/HIV co-infection. However, sampling variations, inter- observers’ variability and the risk of complications have considerably limited the liver biopsy.53,54 Treatment Significance of HBV/HIV co-infection has led to extensive progress in prescription of HBV in HIV-co- infected individuals. Liver injuries are also more common in these patients for whom treatment options have widely developed. Interferon In HBV monotherapy, suppression of viral replica- tion is the aim of therapy. Interferon in form of stand- ard or pegylated may be a proper treatment for chron- ic HBV infection in patients who have not yet started highly active antiretroviral therapy (HAART) for their HIV.59 Interferon is limited to patients who tend to seroconvert; in other words, the female patients with high ALT levels, low HBV DNA levels, and positive HBeAg status in whom liver decompensation Epidemiology of HIV/HBV co-infections has not occurred yet.55,56 It is also a major concern that interferon therapy is just effective with HBV in- fection not HIV.55 It is known that alpha interferon which is available in pegylated form is the most ef- fective therapy for HBsAg positive patients. Levy and Grant have stated that using IFN-α once-weekly for about 16 weeks can be influential in treatment trend. Flulike symptoms, psychiatric effects, bone marrow suppression and thyroid dysfunction are some factors which limit the interferon activity.57 In a study performed by Matthews, patients re- ceiving interferon therapy were shown to get signifi- cantly more improved with pegylated interferon com- pared to nucleosides and nucleotide analogues alone. After 48 of therapy in these patients, HBeAg sero- conversion, HBV DNA suppression and ALT normal- ization became better.58 Nucleoside and Nucleotide Analogues Entecavir, a partial inhibitor of HIV replication along with lamivudine are applied to induce the YMDD mutation in HIV polymerase which is an indication of resistance to therapy. Tenofovir is another option to be chosen for resistance mutations in HIV polymer- ase.55 In coinfected patients who develop resistance to lamivudine, the recommended treatment is tenofovir plus entecavir (because there is no cross-reactivity between these two agents), tenofovir plus lamivudine or emtricitabine. Some evidences suggest that entecavir resistance is inclined by lamivudine re- sistance, but the same studies were performed in pa- tients with very high baseline viral loads; the effi- ciency of entecavir in patients who had low baseline viral loads is unknown. It is assumed that when entecavir is used along with another potent nucleoside analogue in coinfected patients, the sensitivity of HBV would be more durable than when entecavir is used alone as monotherapy.59 Treating HIV and HBV Infections Concurrently To initiate the treatment in co-infected patients, some factors such as combination antiretroviral therapy for HIV infection, the severity of liver disease, probabil- ity of various reactions, and potential adverse events should be taken into account.57 When treatment is necessary for both HBV and HIV infections, HAART is needed for HIV. Using standard therapy for HIV, it WWW.ircmj.com Vol 13 December 2011 859