AIDS: an overview of the pathology

HBV and HIV co-infection: Impact on liver pathobiology and therapeutic approaches

The consequences of hepatitis B virus (HBV) and human immunodeficiency virus (HIV) co-infection on progression of severe liver diseases is a serious public health issue, worldwide. In the co-infection cases, about 90% of HIV-infected population is seropositive for HBV where approximately 5%-40% individuals are chronically infected. In HIV co-infected individuals, liver-related mortality is estimated over 17 times higher than those with HBV mono-infection. The spectrum of HIV-induced liver diseases includes hepatitis, steatohepatitis, endothelialitis, necrosis, granulomatosis, cirrhosis and carcinoma. Moreover, HIV co-infection significantly alters the natural history of hepatitis B, and therefore complicates the disease management. Though several studies have demonstrated impact of HIV proteins on hepatocyte biology, only a few data is available on interactions between HBV and HIV proteins. Thus, the clinical spectrum as well as the complexity of the co-infection offers challenging fronts to study the underlying molecular mechanisms, and to design effective therapeutic strategies.

Infections of the liver in HIV-infected patients

The liver is a common site of pathology in HIV-infected patients. In patients with controlled HIV and minimal immunosuppression, infection with hepatitis viruses is common owing to the risk factors of sexual transmission or parenteral drug use. In patients with AIDS, the liver is a common site of lymphohematogenous dissemination of several infectious pathogens. A thorough diagnostic approach leads to a diagnosis of most hepatobiliary processes. The therapeutic nihilism that has surrounded hepatic disease, including viral hepatitis, is unwarranted, because treatment of the underlying HIV and the hepatic process may improve the quality of life and longevity of these patients.

Findings and benefit of liver biopsies in 46 patients infected with human immunodeficiency virus

AIMS

The aim of this work is to evaluate the role of liver biopsy and to determine the histological findings in patients infected with the human immunodeficiency virus (HIV) who have abnormal liver function tests (LFT).

METHODS

We performed a percutaneous liver biopsy in 46 HIV-seropositive patients with abnormal LFT. Parts of biopsied tissue were used for bacterial and fungal culture and the rest was processed for histological examination including special staining.

RESULTS

Of these 46 patients, 41 patients were males and five were females. The median age was 31+/-6 years. Mycobacterium tuberculosis was the most common histological finding (15 cases). Of 15 tuberculosis patients, 11 (73.3%) had lymphadenopathy and positive acid-fast bacilli (AFB) in node aspiration or biopsy. The other findings included AFB-negative granuloma (eight cases), histoplasmosis (six cases), cryptococcosis (six cases), penicillosis (four cases), viral hepatitis: hepatitis C virus (HCV; one case), hepatitis B virus and HCV infection (one case), fatty liver (two cases), drug-induced hepatitis (one case) and non-specific changes (five cases). There were double infections in three patients. We were able to demonstrate opportunistic infections in 41 cases (89.3%).

CONCLUSIONS

Mycobacterium tuberculosis was the most common histological finding in HIV patients with abnormal LFT in Thailand. Liver biopsy was a useful procedure in evaluating abnormal LFT in HIV patients.

Diagnosis and treatment of hepatic disease in patients with HIV

Liver involvement with opportunistic infections and neoplasms is a well-recognized component of AIDS, affecting most patients. The cause of hepatic disease in these patients may be divided into hepatitis, granulomatous disease, mass lesions, vascular lesions, hepatotoxic drugs, and nonspecific findings. With a rational approach, most patients with AIDS and liver disease can be diagnosed and treated in a cost-effective manner with low morbidity.

Gastrointestinal manifestations

Gastrointestinal disease is a common problem in the setting of HIV-1 infection. As patients live longer and other opportunistic pathogens are suppressed, these problems are becoming even more important in the quality of life.

Liver biopsy findings in 501 patients infected with human immunodeficiency virus (HIV)

Patients infected with human immunodeficiency virus (HIV) are at risk for a variety of liver diseases. We undertook a retrospective study of 501 HIV-seropositive patients to assess the yield of percutaneous liver biopsy. The most common indications for liver biopsy were liver test abnormalities (89.5%), fever for 2 weeks (71.9%), and hepatomegaly (52.0%). The most common biopsy-derived diagnosis was Mycobacterium avium complex (MAC), seen in 87 (17.4%) biopsies. Mycobacterium tuberculosis was found in 13 biopsies (2.6%). In 28 biopsies (5.6%) mycobacteria was seen, but speciation of the organism was not possible. Chronic active viral hepatitis was seen in 60 biopsies (12.0%). Opportunistic hepatic infection from other organisms was found in 14 biopsies (2.8%). The most common neoplasm was lymphoma, which was seen in 12 biopsies (2.4%). MAC infection of the liver was associated with elevated alkaline phosphatase (p = 0.01). Among patients with fever for 2 weeks after an extensive negative workup including bone marrow biopsy, 58.2% had a diagnosis by liver biopsy. Overall, 64.3% of liver biopsies yielded a histopathological diagnosis, 45.7% of which were potentially treatable. We could not evaluate whether liver biopsy had a positive effect on patient outcome and survival, nor did we attempt to prove that liver biopsy resulted in a change in treatment or a change in preprocedure clinical diagnosis. Thus, questions about the efficacy of liver biopsy cannot be answered. Liver biopsy may be a helpful diagnostic tool in HIV-positive patients with fever, liver test abnormalities or hepatomegaly.

Ill thrift and juvenile llama immunodeficiency syndrome

The problem of "ill thrift" or "failure to thrive" in juvenile llamas is widespread and relatively common in the continental United States. Juvenile llama immunodeficiency syndrome (JLIDS) is one of several causes of the problem and is the most common cause of ill thrift in juvenile llamas evaluated at Colorado State University's Veterinary Teaching Hospital. This article will review current knowledge of JLIDS and will briefly discuss other causes of ill thrift in juvenile llamas.

Acquired immunodeficiency syndrome in forensic autopsies

From May 1985 to May 1989, 126 necropsies were performed at the São Paulo City Morgue on cadavers of individuals AIDS victims whose unnatural deaths had prompted police investigations. One hundred and nineteen males and 17 females were included. Ages were most commonly in the 20-to-30 year range. Fifty four deaths occurred in penal institutions, 29 deaths resulted from suicides, 17 deaths from manslaughter, 17 deaths were considered suspicious, 5 willful murders and 4 others also considered suspicious because corpses were found in advanced stages of putrefaction. Inmates, except one man who was strangled, died as a consequence of the disease. During all autopsies, special attention was paid to the high rate of extrapulmonary Mycobacterial infections. Suicides were committed in different ways and the majority of the victims were documented to be still in the initial stages of the disease. Suspicious deaths and deteriorated corpses were the result of negligence of the subject's families. Homicidal deaths occurred in subjects in the terminal stages of the disease inside the hospital where these subjects were assisted and the immunodeficiency certainly contributed to aggravate the injuries leading to death. Attention is drawn to both legal and social issues affecting AIDS victims. The authors believe these issues may pose a hindrance for efficient control of the AIDS epidemic.

Hepatobiliary complications in patients with human immunodeficiency virus infection

Human immunodeficiency virus (HIV) infection has been associated with a number of hepatic and biliary tract disorders. Case reports, series of liver biopsies, and postmortem studies that examined the hepatobiliary system were retrieved with a MEDLARS search and form the basis of this review. The liver and biliary tract are frequently involved with opportunistic infections (most commonly mycobacteria and cytomegalovirus) and neoplasms (mainly Kaposi's sarcoma) in patients with HIV infection. The patients are often asymptomatic but may have elevated levels of serum liver enzymes. These abnormalities are nonspecific. Sulfa drugs, pentamidine, and ketoconazole are the medications used in HIV-related infections that are most likely to result in abnormalities on liver tests. Acalculous cholecystitis and sclerosing cholangitis also occur in HIV infection. Cytomegalovirus and Cryptosporidium are the organisms most commonly associated with these conditions. Imaging studies of the liver may detect parenchymal abnormalities and guide liver biopsy. The role of this procedure in the diagnosis of opportunistic infections and neoplasms is controversial because these lesions are generally disseminated at the time liver abnormalities are evident. A liver biopsy is best used when other less invasive procedures have failed to provide a diagnosis. Endoscopic retrograde cholangiopancreatography is a useful diagnostic procedure with therapeutic potential in patients with abdominal pain, fever, or an elevated serum alkaline phosphatase level.

Cytomegalovirus infection of the appendix in patient with the acquired immunodeficiency syndrome

Disseminated cytomegalovirus infection occurs predominantly in immunocompromised hosts. Involvement of the gastrointestinal tract in the acquired immunodeficiency syndrome is frequent, but to our knowledge there is only one report of involvement of the appendix. In this study, a patient with a history of the acquired immunodeficiency syndrome who presented with fever and an acute abdomen is described. At surgery, appendicitis was found. In the surgical specimen, appendicitis and cytomegalovirus infection were found. Cytomegalovirus should be considered as a possible cause of appendicitis in the acquired immunodeficiency syndrome.

Pathological features of lymphoid tissues in cats with natural feline immunodeficiency virus infection

A range of tissues from a total of 17 cats naturally infected with the feline immunodeficiency virus was examined histologically. In 11 cases, chronic inflammatory lesions were present in various tissues including, most commonly, the intestine, brain and lung. Extensive inflammation in the intestinal wall was present in seven of the cats. No particular bacterial organisms were demonstrated in these inflammatory lesions. A range of changes was present in the lymph nodes, including hyperplasia, atrophy or a mixed pattern. Erythrophagocytosis was a consistent feature. The changes resembled those reported in human acquired immunodeficiency syndrome as a result of infection with human immunodeficiency virus.

CD4-independent, productive human immunodeficiency virus type 1 infection of hepatoma cell lines in vitro

Five hepatoma cell lines, including CZHC/8571, PLC/PRF/5, Hep3B, HepG2, and HUH7, were inoculated with three diverse isolates of human immunodeficiency virus type 1 (HIV-1). Productive infection was noted in all hepatoma cell lines, and expression of viral p24 antigen lasted for over 3 months, but its level decreased in proportion to the number of viable cells. HIV-1 antigens were also found in the cells by immunohistochemical staining and radioimmunoprecipitation assay, as were viral RNA by in situ hybridization and HIV-1-like particles by electron microscopy. Virus yield assays were also positive on supernatant fluids collected from hepatoma cultures inoculated with HIV-1. Despite their susceptibility to infection, all five hepatoma cell lines were negative for CD4 by immunofluorescence and for CD4 mRNA by slot-blot hybridization. In addition, HIV-1 infection of hepatoma cell lines was not blocked by anti-CD4 monoclonal antibody or soluble CD4. Together, these findings clearly demonstrate that all five hepatoma cell lines were susceptible to productive infection by HIV-1 in vitro via a CD4-independent mechanism.