Chronic non-A, non-B hepatitis: ultrastructural and serologic studies

Association of human hepatocellular membrane fusions with non-A, non-B hepatitis

Liver biopsies from patients with alcoholic hepatitis, chemical hepatitis, or viral hepatitis types A, B, or non-A, non-B were examined by electron microscopy. Circular, fused, cytoplasmic membranes were observed in hepatocytes of 17% of patients with hepatitis type B and 92% of patients with hepatitis type non-A, non-B. The membrane alterations were not observed in hepatocytes of patients with the other types of hepatitis. The greater frequency of altered cytoplasmic membranes in hepatocytes of patients with non-A, non-B hepatitis was shown to be statistically significant (p less than 0.05) when compared to that in patients with viral hepatitis type B.

[Hepatitis non-A, non-B: epidemiologic, clinical, serologic and morphologic aspects]

Hepatitis non-A, non-B (HNANB) is due to one or more transmissible agents, probably viruses. Epidemiologically, HNANB is transmitted predominantly by transfusion of blood or plasma derivatives, and percutaneous inoculation, but a non-percutaneous transmission by the fecal-oral route is also established. However, despite 10 years of intense world-wide research, the transmissible agent, or agents, have not been identified and there are no serological assays for either an antigen or an antibody that can be used to detect this infection. The clinical diagnosis of HNANB remains, therefore, a diagnosis of exclusion mainly of hepatitis A and B, Epstein-Barr virus, cytomegalovirus and drug-induced liver disease. In contrast to hepatitis A and B, the clinical and biochemical course of HNANB tends to be less severe and the proportion of asymptomatic and anicteric cases is higher, but fulminant hepatitis and fatalities also occur. Typically, there is a fluctuating waxing and waning pattern of the serum aminotransferase activities in HNANB. HNANB has a relative high tendency to progress to a chronic stage. The exact frequency of HNANB-induced liver cirrhosis and convincing evidence for an association with hepatocellular carcinoma cannot be assessed, although the persistence of the infectious agent in chronic HNANB and the existence of a chronic asymptomatic carrier state have been proved. By light microscopy there is a broad morphologic spectrum of acute and chronic viral hepatitis, but no single pathognomonic lesion exists that allows a reliable distinction to be made of HNANB from hepatitis A and B. Electron microscopy of liver biopsy specimens of chimpanzees, experimentally infected with HNANB agents, permits the visualisation of cytoplasmic changes, which appear to be specific for infection with HNANB viruses. In human liver biopsy specimens from patients with HNANB, identical ultrastructural cytoplasmic changes could not consistently be demonstrated. In contrast, intranuclear aggregates of spherical and tubular particles measuring 20-29 nm, first described in experimental HNANB in chimpanzees, have been repeatedly demonstrated in acute and chronic HNANB in man. These nuclear particles have been considered as compelling evidence of human HNANB infection. The specificity has been challenged, however, by the demonstration of identical particles in other viral and non-viral hepatopathies and in liver biopsies of healthy volunteers. By immune electron microscopy, a multiplicity of virus-like particles are described in association with HNANB.(ABSTRACT TRUNCATED AT 400 WORDS)

The acquired immunodeficiency syndrome: an ultrastructural study

Blood and a variety of tissues from 97 patients with the acquired immunodeficiency syndrome (AIDS) and 25 with the AIDS prodrome were studied ultrastructurally. Tubuloreticular structures (TRS) were found in 85 per cent of the patients with AIDS and in 92 per cent of those with the prodrome. Test tube and ring-shaped forms (TRF), found in 41 per cent of the patients with AIDS and in 8 per cent of those with the prodrome, increased with disease progression. Among the patients with AIDS, as the number of sites examined per case increased, the incidence of TRS and TRF tended to approach 100 per cent, suggesting that they are present in all patients with AIDS. Other changes seen frequently were immunologic capping of blood lymphocytes, intramitochondrial iron in blood reticulocytes and marrow normoblasts, megakaryocytic immaturity and platelet phagocytosis, collections of membranous rings in hepatocytic cytoplasm, suggestive of non-A, non-B hepatitis, and proliferations and engorgement of hepatic Ito cells with lipid. The data suggest that TRS and TRF can be used as diagnostic and prognostic markers.

Electron microscopic evidence of non-A, non-B hepatitis markers and virus-like particles in immunocompromised humans

Characteristic pathological alterations of the liver in chimpanzees inoculated with non-A, non-B hepatitis sera have been described, but no corresponding findings have been reported in humans. Electron microscopic studies of the liver biopsy specimens of two homosexual patients with acquired immune deficiency syndrome, one without hepatitis (Patient 1) and one with chronic active hepatitis in remission (Patient 2), revealed the cytoplasmic tubular structures which are characteristic of chimpanzee non-A, non-B hepatitis. A cluster of 23 nm double-shelled particles was also seen in the cytoplasm of a hepatocyte in patient 1 who had received a blood transfusion 8 days before the biopsy. These particles were smaller than the Dane particles, Epstein-Barr virus, cytomegalovirus or herpes simplex virus, and different from hepatitis A virus particles; the antibodies to all of which are found in high concentration in acquired immune deficiency syndrome patients. These observations may reflect the morphologic findings for non-A, non-B hepatitis infection in humans.

Clinical, biochemical, serological, histological and ultrastructural features of liver disease in drug abusers

Heroin abusers are frequently found to have abnormal liver function tests and hepatic histology. Hepatitis viruses A, B, and NANB, other drugs or drug contaminants and excessive alcohol consumption are factors thought to contribute. One hundred and sixteen heroin abusers attending a London treatment centre were studied. Sixty two (53%) had a raised aspartate transaminase. This was not explained by current infection with hepatitis A and B, cytomegalo or Epstein-Barr viruses, excessive alcohol consumption (greater than 80 g/day) or concomitant drug taking. Abnormal liver function tests were as frequent in those with markers of current or past HBV infection as those without and there was evidence that both HBV infection and the cause of the abnormal liver function tests were acquired in the first few years of intravenous drug abuse. Liver biopsies from eight patients showed chronic hepatitis with a mild lobular and portal inflammatory infiltrate, fatty change and prominent sinusoidal cells. Electron microscopy showed cytoplasmic trilaminar tubular structures and dense fused membranes in dilated endoplasmic reticulum. These clinical, biochemical, serological, and histological features would suggest a major role for NANB virus infection in the aetiology of hepatitis in heroin abusers.

Intracytoplasmic inclusions in human hepatocytes in non-A, non-B hepatitis: an ultrastructural study

An ultrastructural study was carried out on 114 liver biopsies obtained for diagnostic purposes from patients with various pathological disorders of the liver including hepatitis B-related liver disease, non-A, non-B hepatitis, alcoholic liver disease, fatty change, and cryptogenic cirrhosis. The opportunity was taken to evaluate the significance of intracytoplasmic crystalline structures found in the hepatocytes of nine patients with a variety of liver disorders. The cytoplasmic inclusions varied in size up to 2 microns in length and shape and were not limited by membranes. The presence of these inclusions cannot, however, be correlated either specifically with non-A, non-B hepatitis or with other known nonviral liver disease. The functional, physiological, and pathological significance of the crystalline structures remain to be elucidated.

Are nuclear particles specific for non-A, non-B hepatitis?

This study reports the findings of an electron microscopic search for so-called non-A, non-B nuclear particles in liver biopsies from patients with mainly chronic or prolonged liver disease and from chimpanzees. In patients without hepatitis B virus or acute hepatitis A virus serological markers, non-A, non-B-like nuclear particles were seen in hepatocytes in 28 of 31 cases of presumed non-A, non-B hepatitis, but also in 11 of 12 cases of liver disease not usually attributed to hepatitis viruses. They were also seen in 22 of 24 patients with HBsAg, in 3 of 3 patients with anti-HBc and no HBsAg, in 1 of 2 patients with hepatitis A, in a case of cytomegalovirus hepatitis, and in 16 of 19 patients whose serology was not available or inconclusive. The particles were present in 1 of 8 untreated HBsAg-negative chimpanzees and in 2 of 2 HBsAg-positive chimpanzees. They appeared in 4 of 4 chimpanzees developing non-A, non-B hepatitis following exposure to various inocula. Three patterns of particle aggregates were distinguished, all of which had been shown by others in non-A, non-B hepatitis. Dense aggregates were predominant, while others have shown intermediate aggregates more often; reasons for this difference could be technical. No pattern was specific for any condition. Either non-A, non-B-like nuclear particles, although associated with non-A, non-B hepatitis, are not specific for this condition, or non-A, non-B hepatitis viruses are extremely more common than is currently appreciated.

Experimental non-A, non-B hepatitis in chimpanzees: light, electron and immune microscopical observations

Two chimpanzees (Pan troglodytes) were inoculated and cross-challenged with a fibrinogen and factor VIII preparation, respectively. Successful non-A, non-B (NANB) infection was documented by biphasic elevations of aminotransferases (ALT), concomitant hepatitic reactions and typical electron microscopic alterations, the most consistent being dilatation of the endoplasmic reticulum, as well as tubular and sponge-like cytoplasmic inclusions in the absence of nuclear virus-like particles. An anti-nuclear (anti-DNA) antibody of the IgM class in one of the chimpanzees simulating an antiviral antibody is described.

Ultrastructural changes in human hepatocytes in acute non-A, non-B hepatitis

Ultrastructural findings in the liver of a 52-year-old man with acute non-A, non-B (NANB) post-transfusion hepatitis are described. Apart from non-specific alterations also known to occur in hepatocytes in hepatitis A and B--such as proliferation of membranes of smooth endoplasmic reticulum, formation of membrane-bound cytoplasmic vacuoles containing electron-dense material, and accumulation of distorted peroxisomes--unique cytoplasmic changes were observed that have not previously been described in man. A few hepatocytes contained in their cytoplasm tightly packed, bent, parallel structures and small clusters of virus-sized particles. No virus-like material was found in the nucleus of liver cells or in Kupffer and endothelial cells. Closely similar structures have been reported earlier in the acute-phase hepatocytic cytoplasm of chimpanzees with NANB hepatitis. These alterations may represent an ultrastructural hallmark of acute human NANB hepatitis.

Experimental infection of Tamarins with human non-A, non-B hepatitis virus

Non-A, non-B (NANB) viral hepatitis was successfully transmitted to two colony-born Tamarins following inoculation with antihaemophilic factor VIII concentrate or the "H" inoculum. Both animals showed histological and ultrastructural evidence of viral hepatitis, with raised alanine aminotransferase (ALT) levels from the second week after inoculation through to the end of follow-up, 5 months later.