Surgical pathology of the liver in HIV infection

Concomitant Epstein-Barr Virus-associated smooth muscle tumor and granulomatous inflammation of the liver

Epstein-Barr Virus-associated smooth muscle tumor (EBV-SMT) is a rare mesenchymal tumor typically seen in immunocompromised patients. Here, we report a case of EBV-SMT and associated granulomatous inflammation in the liver of a 32-year-old man with history of human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS). To our knowledge, an association of these two lesions has not been previously reported. We review the literature and discuss pathogenesis, differential diagnosis and immunohistochemical (IHC) stains helpful for the diagnosis of this rare entity. Finally, we consider possible explanations for the concomitant presence of these lesions.

Hepatic Granulomas: A Review With Emphasis on Infectious Causes

CONTEXT

Many diseases that cause granulomas or granulomatous inflammation involve the liver. Some of these disease processes are intrinsic hepatic diseases, whereas others are disseminated systemic diseases that involve the liver as well as other organs.

OBJECTIVE

To review the evaluation of granulomas in the liver with an emphasis on infectious causes, as well as the use of special stains, serologic studies, and molecular diagnostic techniques. Pertinent noninfectious causes of hepatic granulomas that are in the differential diagnosis are also discussed.

DATA SOURCES

Literature review and cases acquired during years of practice.

CONCLUSIONS

A wide variety of infectious and noninfectious entities cause hepatic granulomas.

Hepatic granulomas, with an emphasis on infectious causes

Granulomas are aggregates of macrophages, often admixed with other inflammatory cells, which usually result from chronic antigen presentation. Many diseases that produce granulomas involve the liver. Some are intrinsic hepatic diseases, whereas others are disseminated systemic diseases that involve the liver and other organs. Hepatic granulomas are reportedly present in 2% to 10% of all liver biopsy specimens examined in general practice, and of those supposedly as many as 36% have no discoverable etiology even after extensive evaluation of the specimen. This review focuses on the diagnosis of granulomas in infectious diseases affecting the liver, including use of special stains, serologic studies, and molecular diagnostic techniques, and discusses pertinent noninfectious causes of hepatic granulomas that are in the differential diagnosis.

Role of Liver Biopsy in the Evaluation of Hepatitis C Virus Infection in HIV Coinfection

Hepatitis C virus (HCV) coinfection is common in patients infected with human immunodeficiency virus (HIV), because the viruses share common routes of transmission. With the marked increase in life expectancy of HIV-infected patients associated with the use of highly active antiretroviral therapy, HCV infection has become a significant cause of morbidity and mortality in coinfected patients. As a result, there has been increasing attention to adequate assessment of HCV infection during the last several years. Unlike liver enzymes and HCV RNA levels, which can fluctuate widely and do not correlate with the severity of disease, liver biopsy has become the cornerstone in the evaluation of chronic HCV infection. However, there remain important questions and controversies related to adequately determining the histological severity of liver disease and the role of liver biopsy in HIV-HCV-coinfected patients.

Hepatic pathology in AIDS: a pathological study from Mumbai, India

OBJECTIVES

To assess the spectrum of hepatic disorders in AIDS, liver specimens from 171 patients (155 autopsies and 16 biopsies) were reviewed.

METHODS

A retrospective and prospective study of 171 autopsy and biopsy specimens was carried out at a tertiary level hospital in Mumbai, India.

RESULTS

Of the patients included in the study, 127 (74%) were male and 44 (26%) were female. The heterosexual route was the predominant mode of HIV transmission, identified in 163 (95%) patients. A total of 99 of 171 patients (58%) showed significant pathological lesions, and the most common pathological processes involving the liver appeared to be secondary to infections. None of our patients showed isolated infectious diseases of the liver. The spectrum of liver diseases identified was as follows: tuberculosis in 70 patients (41%), cryptococcosis in eight (5%), cytomegalovirus infection in six (3%), hepatitis B infection in five (3%), candidiasis in one (0.5%), malaria in one (0.5%), cirrhosis in six (3%), amyloidosis in one (0.5%) and primary hepatic lymphoma in one (0.5%).

CONCLUSIONS

AIDS patients were found to have a high prevalence of underlying hepatic abnormalities. The spectrum of disease among patients with AIDS in India differs from that in developed countries. Our results suggest that hepatic tuberculosis is more common in AIDS than previously recognized, and that liver specimens should be examined routinely for the presence of acid-fast bacilli.

The clinical spectrum of hepatitis C virus in HIV coinfection

The biochemical, virologic, and histologic spectrum of hepatitis C virus (HCV) in 66 consecutive patients with HIV-HCV coinfection and 119 HCV controls was compared: 86% of coinfected patients had CD4 counts >200 cells/mm3, 51% had a normal alanine aminotransferase (ALT) value, the mean HCV RNA titer was 5.7 log IU/mL, 92% of coinfected patients were of genotype 1, and the mean histologic activity index was 6.86 with advanced fibrosis in 32% of patients. The biochemical, virologic, and histologic findings of HCV in coinfected patients were similar to those observed in HCV controls. For both groups of patients, no clinical, biochemical, or virologic factors could reliably identify patients with advanced fibrosis or cirrhosis, underscoring the importance of liver biopsy in the evaluation of these patients. The spectrum of liver disease in coinfection includes a significant proportion of patients with normal ALT values, and excluding these patients from previous studies has led to an overestimation of HCV disease severity.

Decreased release of nitric oxide (NO) by alveolar macrophages after in vivo loading of rats with either iron or ethanol

Alveolar macrophages were isolated by pulmonary lavage from rats which had been either chronically overloaded with iron by intraperitoneal injections of iron dextran for four weeks, or rendered alcoholic by administration of increasing concentrations of alcohol vapour, also for four weeks. Although the hepatic iron content increased in both groups of animals, only the macrophages isolated from the iron-loaded animals showed a significant increase in iron content (P = < 0.05). Furthermore, in these macrophages there was a significant increase in oxidative tone as demonstrated by a six fold increase in superoxide dismutase activity. In both the iron-loaded and chronically alcoholised macrophages, there was a significant diminution in nitric oxide release after stimulation with lipopolysaccharide and/or interferon-gamma, which impaired the ability of both of these groups of macrophages to inhibit the germination of spores from the fungus Rhizopus, a nitric oxide-dependent process. Such an alteration in nitric oxide release reduces the macrophage's microbicidal activity.

Fatal haemorrhage following liver biopsy in patients with HIV infection

A retrospective review of all 248 liver biopsies performed in patients with HIV infection at two referral centres in London over a 12 year period revealed five cases of major bleeding following biopsy, with four deaths. The risk of major bleeding was 2.0%, and mortality was 1.6% following liver biopsy. The risk of bleeding as much higher than in published series of biopsies done in patients without HIV infection, owing in part to the high prevalence of thrombocytopaenia and clotting abnormalities in patients with HIV infection. HIV infection per se may also increase the risk of bleeding following liver biopsy.

A sonographic-pathological correlation of liver biopsies in patients with the acquired immune deficiency syndrome (AIDS)

The liver is commonly involved in patients with AIDS and a first line investigation for hepatic dysfunction is liver ultrasound (US) which is often abnormal. It is unclear how these US abnormalities correlate with the underlying pathological processes. A retrospective study was performed in 48 patients with HIV disease who had undergone both liver biopsy and hepatic (US), correlating the findings. Only 25% of patients had an entirely normal liver (US) examination and only 10% patients had a normal liver biopsy. The commonest sonographic abnormalities was a diffusely hyperechoic liver seen in 46% of patients and this correlated with steatosis. Forty-four percent of biopsies contained more than one histological abnormality including granulomas, inflammation, steatosis or siderosis. In addition clinically unsuspected pathology was revealed in five of the cases of mycobacterial infection and in three cases of lymphoma. The combination of multiple histological abnormalities, unsuspected pathology, and the altered immune response in this group makes the US findings even less specific than in non-AIDS patients. We recommend that liver biopsy should remain an essential and early part of the management of AIDS patients.

Iron: mammalian defense systems, mechanisms of disease, and chelation therapy approaches

During the past 6 decades, much attention has been devoted to understanding the uses, metabolism and hazards of iron in living systems. A great variety of heme and non-heme iron-containing enzymes have been characterized in nearly all forms of life. The existence of both ferrous and ferric ions in low- and high-spin configuration, as well as the ability of the metal to function over a wide range of redox potentials, contributes to its unique versatility. Not surprisingly, the singular attributes of iron that permit it to be so useful to life likewise render the metal dangerous to manipulate and to sequester. All vertebrate animals are prone to tissue damage from exposure to excess iron. In order to protect them from this threat, a complex system has evolved to contain and detoxify this metal. This is known as the iron withholding defense system, which mainly serves to scavenge toxic quantities of iron and also for depriving microbial and neoplastic invaders of iron essential for their growth. Since 1970, medical scientists have become increasingly aware of the problems involved in cellular iron homeostasis and of the disease states related to its malfunctioning. Scores of studies have reported that excessive iron in specific tissue sites is associated with development of infection, neoplasia, cardiomyopathy, arthropathy and a variety of endocrine and neurologic deficits. Accordingly, several research groups have attempted to develop chemical agents that might prevent and even eliminate deposits of excess iron. A few of these drugs now are in clinical use, e.g. deferiprone (L1). In the present review, we focus on recent developments in (i) selected aspects of the iron withholding defense system, and (ii) pharmacologic methods that can assist the iron-burdened patient.

Human immunodeficiency virus infection and hepatitis C pathology

To investigate the possible influence of human immunodeficiency virus (HIV) infection on hepatitis C virus-related liver disease, liver morphology was evaluated in 160 HBsAg-negative patients with chronic hepatitis C, including 68 HIV-positive and 92 HIV-negative cases. No differences were detected in the severity of necro-inflammatory hepatic lesions between HIV-negative and HIV-positive patients when the CD4+ lymphocytes count exceeded 400 cells/mm3. In contrast, HIV-positive patients with CD4+ lymphocytes below 400 cells/mm3 showed a significantly lower grade of portal inflammation and piecemeal necrosis. These results suggest that liver lesions in hepatitis C may largely depend on immunomediated mechanisms.

Iron overload in multiply transfused patients who are HIV seropositive

AIMS

To assess histologically the amount of iron deposited in liver biopsy specimens from HIV positive patients; and to perform estimations of liver iron on tissue from patients with an increase in parenchymal stainable iron. To correlate the amount of blood transfused and the degree of iron overload.

METHODS

Liver biopsy specimens (n = 120) from 109 HIV positive patients, 74 of whom had AIDS, were examined retrospectively and the amount of iron, as visualised with Perls's stain, was graded. Fibrosis was assessed using connective tissue stains. Estimations of liver iron were performed on tissue retrieved from paraffin wax blocks in cases with histological grade 3 or 4 iron overload. The amount of blood transfused before liver biopsy was determined from the notes for each patient.

RESULTS

Fifteen of the 120 liver biopsy specimens had significantly increased amounts of iron in their hepatocytes, as assessed histologically, and this was confirmed in seven cases by measurement of liver iron. There was a close correlation between the amount of blood transfused and the degree of iron overload. In the initial biopsy specimens only one case showed portal tract expansion. Three of the five patients who had repeat biopsies, however, showed progressive fibrosis.

CONCLUSION

Multiply transfused HIV positive patients may develop clinically important iron overload and are at risk of developing progressive fibrosis. Superimposed liver disease, especially viral hepatitis, in these high risk patients may exacerbate the effects of the iron overload.

Ultrasound findings in hepatic mycobacterial infections in patients with acquired immune deficiency syndrome (AIDS)

Ultrasound findings in 12 AIDS patients with abdominal mycobacterial infections were reviewed and correlated with liver histology. Liver ultrasound abnormalities were common--present in 4/5 patients with Mycobacterium avium-intracellulare (MAI) and 7/7 patients with Mycobacterium tuberculosis (MTB) infection. The commonest ultrasound abnormality of the liver was a generally 'bright' liver, seen in 7/12 patients. Focal liver lesions were seen in 5/7 patients with MTB but were not seen in any patients with MAI infection. Both hyperechoic (two patients) and hypoechoic (three patients) lesions were seen. Lymphadenopathy as demonstrated on abdominal ultrasound was a relatively infrequent finding--only seen in three patients with MTB, all of whom also had focal liver lesions. On histology, 8/12 patients showed fatty infiltration and 8/12 showed granuloma. Abnormalities are commonly seen on ultrasound examination of the liver in AIDS patients with abdominal mycobacterial infections but are non-specific and ultrasound guided biopsy is indicated to confirm the diagnosis and exclude other disease.