Non-viral Causes Research Articles

Pediatric Cough and Cold Preparations

Pediatric Cough and Cold Preparations

Molecular viral oncology of hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is the fifth most common cancer, but the third leading cause of cancer death, in the world, with more than 500,000 fatalities annually. The major etiology of HCC/liver cancer in people is hepatitis B virus (HBV), followed by hepatitis C virus infection (HCV), although nonviral causes also play a role in a minority of cases. Recent molecular studies confirm what was suspected: that HCC tissue from different individuals have many phenotypic differences. However, there are clearly features that unify HCC occurring in a background of viral hepatitis B and C. HCC due to HBV and HCV may be an indirect result of enhanced hepatocyte turnover that occurs in an effort to replace infected cells that have been immunologically attacked. Viral functions may also play a more direct role in mediating oncogenesis. This review considers the molecular and cellular mechanisms involved in primary hepatocellular carcinoma, using a viral perspective.

Apolipoprotein E-ϵ4 protects against severe liver disease caused by hepatitis C virus

The outcome of infection with hepatitis C virus (HCV) varies greatly. The virus associates with serum lipoproteins, including those containing apolipoprotein E (apoE) and apolipoprotein B (apoB), and may enter cells via the low-density lipoprotein receptor (LDLR). ApoE genotypes can affect the extent of damage in diseases caused by 2 other viruses—herpes simplex virus type 1 (HSV1; in Alzheimer's disease and herpes labialis) and human immunodeficiency virus (HIV). We therefore investigated whether specific apoE and apoB alleles were associated with different outcomes of HCV infection. A total of 156 anti–HCV-positive patients and 104 non–HCV-infected patients were studied. Liver biopsy specimens from patients with chronic HCV infection (n = 111) were assessed for disease severity by the Knodell system. ApoE and apoB genotypes were determined by standard polymerase chain reaction (PCR) methods. There was no significant difference among the apoE genotypes of HCV-infected subjects compared with previously published population data, or between HCV-RNA positive or negative patients. However, chronically HCV-infected subjects with mild liver disease (n = 65) had a significantly higher apoE-ϵ4 allele frequency (20.0%) than those (n = 46) with severe disease (6.5%). ApoB alleles alone or in combination with apoE were not associated with mild or severe disease. The overall apoE allele frequencies of patients with liver disease not caused by HCV were similar to those of the total HCV group and in contrast to the HCV patients, the apoE allele frequencies were similar in those patients with no or mild fibrosis as compared with those with bridging fibrosis or cirrhosis. In conclusion, carriage of an apoE-ϵ4 allele may be protective against liver damage caused by HCV, but not against damage due to various nonviral causes. This is yet another case in which apoE may determine the severity of a viral disease. (H EPATOLOGY 2002;36:456-463.)

Expression of GP73, a resident Golgi membrane protein, in viral and nonviral liver disease

GP73 is a novel type II Golgi membrane protein of unknown function that is expressed in the hepatocytes of patients with adult giant-cell hepatitis (Gene 2000;249:53-65). Its expression pattern in human liver disease and the regulation of its expression in hepatocytes have not been systematically studied. The aims of the present study were to compare GP73 protein levels in viral and nonviral human liver disease and in normal livers, to identify its cellular sources, and to study the regulation of its expression in hepatoma cells in vitro. GP73 protein levels were quantitated in explant livers of patients with well-defined disease etiologies and compared with the levels in normal donor livers. GP73-expressing cells were identified immunohistochemically. GP73 expression in vitro was studied by Western blotting and immunofluorescence microscopy in HepG2 and SK-Hep-1 cells and in the HepG2-derived, hepatitis B virus (HBV)-transfected HepG2215 and HepG2T14.1 cell lines. Whole organ levels of GP73 were low in normal livers. Significant increases were found in liver disease due to viral causes (HBV, HCV) or nonviral causes (alcohol-induced liver disease, autoimmune hepatitis). In normal livers, GP73 was constitutively expressed by biliary epithelial cells but not by hepatocytes. Hepatocyte expression of GP73 was dramatically up-regulated in diseased livers, regardless of the etiology, whereas biliary epithelial cell expression did not change appreciably. GP73 was present at high levels in HepG2215 cells (a cell line that supports active HBV replication), but was absent in HepG2T14.1 cells (an HBV-transfected cell line that does not support HBV replication) and in HBV-free HepG2 cells. In SK-Hep-1 cells, GP73 expression was increased in response to interferon gamma (IFN-γ), and inhibited by tumor necrosis factor α (TNF-α). In conclusion, increased expression of GP73 in hepatocytes appears to be a general feature of advanced liver disease, and may be regulated via distinct pathways that involve hepatotropic viruses or cytokines. (H EPATOLOGY 2002;35:1431-1440.)

Hepatitis C infection is not associated with an increased risk of acute liver allograft rejection

ND-STAGE CHRONIC liver disease (ESCLD) due to hepatitis C virus (HCV) infection is now the most frequent indication for orthotopic liver transplantation (OLT) in North America. HCV is a lymphotrophic virus and has the potential to stimulate immune-mediated diseases. Other lymphotrophic viruses such as cytomegalovirus have been associated with increased risk of rejection following OLT, but little information is available regarding the role of HCV in this respect. 1 In the setting of organ transplantation the immunostimulatory effects of HCV may increase the risk of acute and chronic allograft rejection. A recent report in renal transplant recipients suggests an increased risk of renal allograft rejection in patients with HCV. 2 To investigate the role of HCV in liver allograft rejection and survival, we identified all recipients of first OLT with ESCLD secondary to HCV at our unit during the 5-year period from January 1, 1992 to December 31, 1996 and compared them to contemporaneous patients with nonviral causes of liver disease (non-HCV).

Hepatitis after liver transplantation: the role of the known and unknown viruses.

This study was designed to determine the cause of posttransplantation hepatitis in patients undergoing transplantation for liver disease of nonviral cause; the role of acquired hepatitis B virus (HBV), hepatitis C virus (HCV), and hepatitis G virus (HGV) in posttransplantation hepatitis; and the course of posttransplantation hepatitis of unknown cause. Two hundred forty-three patients underwent transplantation for nonviral liver diseases (mean age, 48 years; 103 men, 140 women). Serological and virological assays for HBV and HCV were performed pretransplantation to exclude preexisting infection and posttransplantation to investigate the cause of posttransplantation hepatitis. Histology was graded on all available biopsy specimens; posttransplantation hepatitis was assessable in 150 patients. Posttransplantation hepatitis was present in 29% (44 of 150) of the patients after a median follow-up of 47 months (range, 1 to 101 months). Actuarial survival was significantly lower in patients with posttransplantation hepatitis compared with patients without (71% v 89% at 5-year follow-up; P = .03). HCV and HBV were identified posttransplantation in 14% and 9% of patients with hepatitis, respectively. After the exclusion of HCV and HBV infection, 22% (33 of 150) of the patients had posttransplantation hepatitis of unknown cause. HGV was present in 58% of these patients, but HGV was equally prevalent in patients without posttransplantation hepatitis. When patients with HBV and HCV were excluded, there was no difference in survival between patients with posttransplantation hepatitis compared with patients without (P = .08, log-rank test). Posttransplantation hepatitis was present in approximately 30% of the patients undergoing transplantation for nonviral diseases, with a median follow-up of 47 months. Known hepatitis viruses (HBV, HCV) were present in one fourth of the patients with posttransplantation hepatitis; 22% (33 of 150) of the patients had hepatitis of unknown cause, suggesting that other, as yet undiscovered, hepatitis viruses may exist.

Molecular epidemiology of Cryptosporidium parvum infection

Cryptosporididal infection is one of the most common nonviral causes of diarrhoea in humans and livestock, worldwide. Most clinical infections cause acute transient diarrhoea but persistent infections may develop causing severe chronic, often life-threatening disease, particularly in immunocompromised individuals. The parasite is considered to be the most commonly detected enteropathogen affecting AIDS patients and presently no effective treatment is available. In the absence of effective drugs to treat this ubiquitous infections, the control and clinical management of cryptosporidiosis depends upon rapid, accurate and sensitive identification and characterisation of the aetiological agent, both in clinical specimens and environmental samples. Conventional detection of Cryptosporidium is time consuming, insensitive and generally requires the skills of highly trained operators. Molecular biology has provided the basis for the development of a new generation of diagnostics. The detection and characterisation of isolates of Cryptosporidium using molecular tools are discussed.

Hepatitis G virus co-infection in liver transplantation recipients with chronic hepatitis C and nonviral chronic liver disease.

Hepatitis G virus (HGV) is a newly described RNA virus that is parenterally transmitted and has been found frequently in patients with chronic hepatitis C infection. To determine the impact of hepatitis G virus co-infection on morbidity and mortality following liver transplantation, we measured HGV RNA by polymerase chain reaction in pre and posttransplantation sera from a cohort of patients transplanted for chronic hepatitis C and a control group of patients transplanted for nonviral causes who were negative for hepatitis C virus (HCV) RNA in serum. The overall prevalence rate of HGV RNA in transplanted patients with chronic hepatitis C was 20.7%. HGV infection was present before transplantation in 13% while it appeared to have been acquired at the time of transplantation in 7.4%. Mean serum alanine aminotransferase activity, hepatic histological activity, and patient and graft survival were similar between HGV-positive and HGV-negative patients. The prevalence rate of HGV RNA in transplanted controls was 64% (P < .01) with a significantly higher rate of acquisition of HGV infection following transplantation (53%, P < .001) when compared with patients with chronic hepatitis C. Mean serum alanine aminotransferase activity was significantly lower in the control patients with HGV infection alone following transplantation than in patients co-infected with hepatitis C (37 +/- 9 vs. 70 +/- 33 U/L, P < .01). Thus, HGV is frequently found in transplantation patients co-infected with hepatitis C although it appears to have minimal clinical impact. In patients transplanted for nonviral causes of end-stage liver disease, a high rate of hepatitis G acquisition at the time of transplantation may occur but does not appear to predispose to chronic hepatitis.

Seroepidemiology of hepatitis B virus (HBV) and hepatitis C virus (HCV) and relationship to alanine transferase (ALT) in Saudi workers at Yanbu industrial city

To study the epidemiology of Hepatitis B virus (HBV) and Hepatitis C virus (HCP) in a relatively new industrial community in Yanbu, and to find out whether any relationship exists between increased serum Alanine Transferase (ALT) and HBV infection. A group of Saudi male workers (n=332) (mean age = 32 years) were screened for Hepatitis B core antibody (anti-HBc), Hepatitis B surface antigen (HBsAg), Hepatitis C virus antibody (anti-HCV), and Alanine Transferase (ALT) level and the results were correlated with age and marital status. Overall, the prevalence of anti-HBc, HBsAg, and anti-HCV were 23.2%, 7.7% and 0.6% respectively. Age-related HBsAg carrier rates were 7.8%, 6.4% and 9.4% for age groups 18-20, 21-30 and over 30 years respec-tively. Anti-HBc positivity rates lucre 7.8%, 24.3% and 23.1 M for the same age groups. Anti-HCV was positive in only two cases (0.6%) of all subjects. Con-sidering marital status, HBsAg and anti-HBc positivity rates were 7.8% and 20.5% for single subjects compared with 7.4% and 24.5% for married subjects (P=> 0.5 and > 0.5). Twenty-two percent of all subjects had ALT levels above 35 U/L with no correlation between the increase of ALT and anti-HBc or HBsAg positivity. THE FINDINGS OF THIS WORK: (1) Support the notion of relatively low prevalence of HCV in the Saudi Population as compared to HBV. (2) Provide clues regarding possible routes of transmission of HBV in Saudis that may help in vaccination policies for control of HBV infection. (3) Emphasize the fact that ALT level is an independent factor of HBV infection, and (4) Signify the need to screen industrial workers fir non-viral causes of liver disease.

Viral Arthritis: The Lessons of Parvovirus B19

Viruses are among the most common and least recognized causes of joint symptoms--including syndromes misclassified as seronegative rheumatoid arthritis. Parvovirus B19 is notably underappreciated in this role. Many cases resolve spontaneously. The challenge is to exclude nonviral causes of joint disease.

Abortion of virologically negative foetuses following experimental challenge of pregnant pony mares with equid herpesvirus 1.

From 1988 to 1991, 51 pregnant pony mares were challenged intranasally or by aerosol with an isolate of EHV-1 (AB4) originally recovered from a quadriplegic mare. This resulted in 32 abortions, occurring from 9 to 29 days after infection. In 14 of the early abortions (Days 9-14), EHV-1 was not demonstrated in the foetal tissues by virus isolation or immunostaining despite no other non-viral cause for the abortion being evident. Application of the polymerase chain reaction to foetal tissues from 9 of these cases also proved negative. One of the 14 mares was destroyed immediately after abortion, and post-mortem examination revealed severe and widespread vasculitis, thrombosis and secondary ischaemic damage in the endometrium with replication of EHV-1 in endothelial cells. These findings suggest that EHV-1 abortion can occur due to endometrial damage without the establishment of a foetal infection.

Post-transfusion hepatitis after open-heart surgery in Finland--a prospective study.

A countrywide prospective study on open-heart surgery patients was performed between 1987 and 1989 to determine the prevalence and nature of post-transfusion hepatitis in Finland. Altogether 685 coronary by-pass operation patients, who received on average 12.3 units of blood products, were postoperatively followed for 6 months. Ten blood samples were drawn from each patient. Hepatitis was diagnosed when the alanine aminotransferase values exceeded the upper normal value 2.5 times in one sample and twice in another, and non-viral causes could reasonably be excluded. Eleven hepatitis cases (1.6%) were recorded with a mean incubation period of 8.4 weeks; all represented the non-A, non-B type. The majority had mild symptoms or were asymptomatic but two became icteric. Six patients (55%) had abnormal alanine aminotransferase values for at least 6 months, which indicates possible chronicity. These 685 open-heart surgery patients received a total of 8,436 units of blood products; thus the rate of NANBH cases per 1000 units was as low as 1.3. This is less than recently reported in six other prospective studies.

Low incidence of non-A, non-B post-transfusion hepatitis in London confirmed by hepatitis C virus serology

To see whether the introduction of screening tests for post-transfusion non-A, non-B hepatitis (NANBH) in the UK would be worth while, the incidence of such hepatitis was assessed among patients receiving blood during operations at five hospitals served by the North London Blood Transfusion Centre. 387 patients, who each received blood or blood components from an average of 3 donors were followed up prospectively and blood samples were taken every 2 weeks for 3 months and then each month for a further 3 months. 229 patients also provided a sample at 12 months. All available patient and donor samples were tested for alanine aminotransferase concentrations and for antibody to hepatitis C virus (anti-HCV) by ELISA. Repeatedly anti-HCV positive samples were submitted to supplementary HCV assays. 1 of the 387 patients showed biochemical evidence of acute post-transfusion NANBH after exclusion of non-viral causes. Anti-HCV developed in this patient and the seroconversion was confirmed by recombinant immunoblot assay and polymerase chain reaction. Serum from 1 of the 8 donors whose blood he received was positive for anti-HCV by all three methods. In another patient HCV seroconversion was shown by ELISA but alanine aminotransferase concentrations remained normal throughout follow-up. His samples and those of his 2 donors were negative for HCV by the polymerase chain reaction. A third patient showed rises in alanine aminotransferase compatible with post-transfusion NANBH, but serology and polymerase chain reaction assays for HCV were negative for her samples and those of her donors. Anti-H CV reactivity likely to be false positive (negative by both confirmatory tests and no adverse effects in recipients) was seen in 6 of 1283 donors. This study, despite its being carried out in the part of the UK with the highest frequency of infectious markers in blood donations, has shown a very low incidence of post-transfusion NANBH.

Acute exanthems in children. Clues to differential diagnosis of viral disease.

The numerous viral skin diseases that affect children present a diagnostic challenge to the clinician. Most of these diseases may be conveniently grouped according to the clinical appearance of the exanthem as maculopapular, petechial, papular, or vesicular. In some situations, viral infection may be difficult to differentiate clinically from nonviral disease; thus, extensive laboratory evaluation is sometimes necessary to pinpoint the virus involved. Nonviral disease should be considered in the differential diagnosis of a patient with skin eruptions, especially of the maculopapular type. Common nonviral causes include Kawasaki disease, toxic shock syndrome, and drug reactions.

The incidence of cryptosporidiosis: a two-year prospective survey in a children's hospital.

A two-year prospective survey of patients with diarrhoea at a children's hospital detected 65 cases of cryptosporidiosis; 56 were index cases representing 1.4% of patients examined. There was a marked seasonal variation with fewer index cases in July-September (0.4-0.6%) than February-April (3-5%). All four adult cases were contacts of infected children and 21 (32%) of the patients were 12 months old or younger. Cryptosporidium was the fourth commonest diagnosed cause of gastroenteritis, the second most common non-viral cause, was responsible for 7.2% of all cases, and 14.7% of non-viral cases where a cause was identified. As such it should be sought routinely in cases of gastroenteritis in children.

Frequency of Chlamydia trachomatis as the cause of pharyngitis.

We evaluated the incidence of Chlamydia trachomatis as the etiologic agent of uncomplicated pharyngitis by the cell culture procedure recommended by the Centers for Disease Control, Atlanta, Ga., and by the MicroTrak direct immunofluorescent stain (Syva Co., Palo Alto, Calif.) for elementary bodies on throat swabs collected from 126 symptomatic patients. Of the 126 cultures, 8% were positive for group A beta-hemolytic streptococci. Of 126 chlamydia cultures, none was positive. The MicroTrak test gave one borderline positive result. In contrast to a previously published report that C. trachomatis is the most frequent nonviral cause of adult pharyngitis (A. L. Komaroff, M. D. Aronson, T. M. Pass, C. T. Ervin, and W. T. Branch, Jr., Science 222:927-929, 1983), our data indicated an infection rate of less than 1%.

Cryptosporidiosis in Immunocompetent Patients

The intestinal protozoan cryptosporidium is known to cause diarrhea in immunocompromised patients, but few cases have been reported in detail in immunocompetent persons. During a 12-month period, we identified cryptosporidium in the stools of 43 immunocompetent patients. The numbers of cases were increased in those under 4 years old and in those from 30 to 39 years old. Of 30 index cases, 23 (77 per cent) were diagnosed in the late summer or the fall. Fifteen of the 43 patients (35 per cent) had other gastrointestinal pathogens, of which only Giardia lamblia was statistically associated with cryptosporidium. In the 28 patients in whom other gastrointestinal pathogens were not identified, the clinical manifestations were predominantly watery, nonbloody diarrhea and, less commonly, abdominal discomfort, anorexia, fever, nausea, and weight loss. The infection was self-limited in all 43 patients. Clustering of cases occurred in a day-care center and in two families. These clinical observations confirm worldwide findings and suggest that cryptosporidium is a relatively common nonviral cause of self-limited diarrhea in immunocompetent persons in the northeastern United States.

Cell killing by simian virus 40: The sequence of ultrastructural alterations leading to cellular degeneration and death

Lytic infection of CV-1 cells with SV40 results in a sequence of ultrastructural alterations characterized by primary swelling of endoplasmic reticulum, followed by condensation of mitochondria, and finally, by swelling of most other membrane systems, including mitochondria and nuclear membranes. Lysosomes, stained for acid phosphatase activity or labeled with ferritin, were found to be relatively stable structures. They remained intact in cells which had become trypan blue stainable and in which the morphology of other organelles had become grossly distorted. Lytic SV40 infection was also characterized by an increase in the intracellular Na +/K + ratio. Important similarities between the pattern of cytopathogenesis resulting from SV40 infection and that resulting from a variety of nonviral causes are noted.

Teratocarcinomas and Other Neoplasms as Developmental Defects in Gene Expression

The chapter discusses the normal stem-cell systems, evidence for the aberrant developmental nature of tumors, first through examples of spontaneous differentiation of malignant stem cells; and then by describing experimental systems for inducing the differentiation of such cells, with respect to teratocarcinomas as well as a number of other kinds of tumors. The chapter deals with mammalian tumors, as they occur in vivo; some information from other organisms and from transformed cell culture lines is included. The investigations-along with the in vivo lessons learned from tumors, such as teratocarcinomas, support the hypothesis that normal cells contain genes that are capable of inducing malignancy if they are expressed at abnormal levels. The experiments demonstrating completely normal differentiation of once-malignant mouse teratocarcinoma cells have supplied a focal point in the chapter, because they reveal with exceptional clarity that changes in gene expression affecting development are one of the crucial aspects of neoplasia. While it is conceivable that the apparently nonmutational basis of malignancy in teratocarcinomas may be relatively exceptional among tumors, it is nevertheless likely that these tumors furnish-albeit at a developmentally primitive stage-a widely applicable model of malignancy as a developmental defect in the behavior of ordinary genes. The malregulated expression of developmentally relevant cellular genes—whether due to mutational or nonmutational, viral or nonviral causes—appears to underlie all cancers, and the genes at issue are any of the numerous banal or ordinary genes involved in cell growth and differentiation, rather than special or exotic cancer genes.

9 - The Dominant Role of Non-A, Non-B in the Pathogenesis of Post-transfusion Hepatitis: A Clinical Assessment

Despite the exclusion of commercial donors and the introduction of sensitive radioimmunoassays for hepatitis B surface antigen, approximately 8 to 10 per cent of prospectively followed patients continue to develop post-transfusion hepatitis. Serological evaluation of these residual hepatitis cases showed them to be distinct from hepatitis B, hepatitis A, cytomegalovirus and the Epstein-Barr virus. These cases have been tentatively designated non-A, non-B and now compromise approximately 90 per cent of post-transfusion hepatitis. There is increasing evidence that non-A, non-B hepatitis is also spread by routes other than blood. In the absence of a specific serological test, the diagnosis of non-A, non-B hepatitis depends on the clinical exclusion of non-viral causes of hepatocellular injury and on the serological exclusion of other known hepatitis viruses. The clinical pattern of non-A, non-B hepatitis is characterized as follows: (1) The incubation period tends to be intermediate between type A and type B hepatitis, but considerable overlap exists. Most cases occur between five and 12 weeks after percutaneous exposure: (2) Non-A, non-B hepatitis tends to be less acutely severe than type B hepatitis; two thirds to three quarters of cases are anicteric, demonstrate only mild to moderate transaminase elevations and are symptomatically mild. Individual cases may, however, be clinically and biochemically severe and cannot be distinguished from acute type A or type B hepatitis. (3) A striking feature of non-A, non-B hepatitis is its propensity to progress to chronic liver disease. Up to 50 per cent of patients have elevated transaminase values in excess of one year and the majority of such patients, when biopsied, demonstrate histological features of chronic active hepatitis. Approximately 10 per cent show features of cirrhosis. Despite these histological changes, the chronic liver disease of non-A, non-B hepatitis seems, in most cases, to be slowly resolving rather than rapidly progressing. Non-A, non-B hepatitis has now been repeatedly induced in chimpanzees using human acute and chronic phase inocula. These studies establish the existence of a transmissible agent and of a chronic asymptomatic carrier state. Transmission appears to be very similar to that for type B hepatitis. Additional studies in humans and chimpanzees suggest that there may be more than one non-A, non-B agent. At present, there is no confirmed serological test for detecting this agent(s). The development of such a test would represent a major breakthrough in the prevention of post-transfusion hepatitis and in better defining the epidemiological pattern and clinical consequences of this increasingly prevalent disease.