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Virus Antigens (virus + antigen)

Distribution by Scientific Domains

Medical Sciences	80%

Selected Abstracts

Erythema dyschromicum perstans and hepatitis C virus infection

INTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 5 2001
George J. Kontochristopoulos MD
A 48-year-old woman with a 10-month history of widespread, hyperpigmented, slightly pruritic macules, with a red border, involving the trunk and the proximal limbs (Fig. 1) was referred to our outpatient department. The oral mucosa, palms, soles, scalp, and nails were normal. Figure 1. Multiple hyperpigmented macules with an active border on the trunk Laboratory tests showed elevated liver enzymes [alanine aminotransferase (ALT), 68 IU/L (normal value, <,40 IU/L); aspartate aminotransferase (AST), 41 IU/L (normal value, <,40 IU/L)], the presence of antibodies to hepatitis C virus (anti-HCV) and HCV RNA (Amplicor Roche). In addition, cryoglobulinemia type III (IgM,,,, IgG,,,) was detected with a high cryocrit value, and there was detectable C-reactive protein, rheumatoid factor, and a low titer of antinuclear antibodies (1 : 80). A percutaneous liver biopsy showed changes compatible with mild chronic hepatitis (grade, 6; stage, 0). The possible source of infection was unknown, as the patient had no history of parenteral transmission (e.g. blood transfusions, intravenous illicit drug use). A skin biopsy specimen from the active border of a lesion showed hyperkeratosis, parakeratosis, and hydropic degeneration of the basal cell layer, with the formation of colloid bodies in the epidermis. A moderate perivascular lymphohistiocytic infiltrate with melanophages and free melanin granules was observed in the upper dermis (Fig. 2). Immunostaining of paraffin-embedded tissue sections with the TORDJT-22 IgG1 mouse monoclonal antibody to HCV (Biogenex, Son Ramon, USA), which is specific for the nonstructural region of HCV (NS3-NSH, C100 antigen) using the avidin,biotin,peroxidase complex (ABC) as well as the alkaline phosphatase antialkaline phosphatase (APAAP) methods, failed to detect HCV in the lesion of erythema dyschromicum perstans (EDP) (Nakopoulou L, Manolaki N, Lazaris A et al. Tissue immunodetection of C100 hepatitis C virus antigen in major thalassemic patients. Hepato-Gastroenterol 1999; 46: 2515,2520). Direct immunofluorescence showed IgG, IgM, IgA, and fibrinogen deposits on colloid bodies. EDP was diagnosed on the basis of these clinical and laboratory findings. Figure 2. Hydropic degeneration of the basal cell layer with colloid bodies in the epidermis. Moderate perivascular lymphohistiocytic infiltrate with melanophages and free melanin granules in the upper dermis (hematoxylin and eosin, ×,200) The patient was treated with interferon-,2b (Intron-A, Schering Plough Athens, Greece), 3 MU thrice weekly subcutaneously for 12 months, with additional topical steroid application. There was no response to this treatment with new lesions appearing in previously unaffected areas of the trunk and extremities. HCV RNA remained persistently positive. Thus, a modified regimen with interferon-,2b, 6 MU thrice weekly for 6 months, was tried. At the end of the treatment course, the eruption of EDP had greatly improved. Liver enzymes were normal (ALT, 22 IU/L; AST, 24 IU/L) and HCV RNA had become negative. Four months later, however, cutaneous lesions reappeared and hepatitis C relapsed. At this time point, combination therapy of interferon-,2b, 3 MU thrice weekly, with ribavirin, 1000 mg daily, was given. Six months later, liver enzymes were normal (ALT, 42 IU/L; AST, 39 IU/L), HCV RNA was negative, and the lesions of EDP had resolved. [source]

Acute myelomonocytic leukaemia with short-term spontaneous remission in a cat

AUSTRALIAN VETERINARY JOURNAL, Issue 6 2008
ME MYLONAKIS
A 2-year-old, spayed female domestic shorthair cat was referred with a history of anorexia and depression of 1 week duration. On physical examination, the cat was lethargic and febrile, with splenomegaly, anisocoria and ulcerative stomatitis. A complete blood count (CBC) and a biochemistry profile showed leukocytosis, numerous blast cells in the peripheral blood, thrombocytopenia, hyperglobulinaemia and a positive test for feline leukaemia virus antigen. A diagnosis of acute myelomonocytic leukaemia was made on the basis of the results of bone marrow cytology, histopathology, and immunochemistry (CD3, CD79a, lysozyme, and myeloperoxidase) tests. Following an unexpected 1-month period of clinical and clinicopathological remission without chemotherapy, the cat relapsed and died 1 week later. [source]

Fluctuations in concentration of two potyviruses in garlic during the growing period and sampling conditions for reliable detection by ELISA

ANNALS OF APPLIED BIOLOGY, Issue 1 2002
C I DOVAS
Summary To optimise sampling conditions for the detection by ELISA of Onion yellow dwarf virus (OYDV) and Leek yellow stripe virus (LYSV), the most important viral pathogens of garlic worldwide, relative virus concentrations were determined during the growing period and in different leaf parts by DAS-ELISA. Both viruses were found to have uneven distributions in garlic plants, with the tips of the two latest fully developed leaves showing the highest concentrations and the oldest leaves the lowest concentrations. The tips of the youngest leaves were found to have higher virus concentrations than their middle and basal sections. In the older leaves, viruses were distributed more uniformly in the three leaf sections. In the oldest leaves virus levels in the leaf tips were significantly decreased. The concentrations of OYDV and LYSV increased until March, whereas later on they decreased. During storage of leaf samples at 6°C for 15 days, a loss was found of both virus antigens of more than 80%, and during 109 days of storage at ,30°C a loss of more than 90% was found. [source]

Elevated Epstein,Barr virus-encoded nuclear antigen-1 immune responses predict conversion to multiple sclerosis

ANNALS OF NEUROLOGY, Issue 2 2010
Jan D. Lünemann MD
Objective The aims of the study were to determine the immune responses to candidate viral triggers of multiple sclerosis (MS) in patients with clinically isolated syndromes (CISs), and to evaluate their potential value in predicting conversion to MS. Methods Immune responses to Epstein,Barr virus (EBV), human herpesvirus 6, cytomegalovirus (HCMV), and measles were determined in a cohort of 147 CIS patients with a mean follow-up of 7 years and compared with 50 demographically matched controls. Results Compared with controls, CIS patients showed increased humoral (p < 0.0001) and cellular (p = 0.007) immune responses to the EBV-encoded nuclear antigen-1 (EBNA1), but not to other EBV-derived proteins. Immunoglobulin G (IgG) responses to other virus antigens and frequencies of T cells specific for HCMV and influenza virus gene products were unchanged in CIS patients. EBNA1 was the only viral antigen with which immune responses correlated with number of T2 lesions (p = 0.006) and number of Barkhof criteria (p=0.001) at baseline, and with number of T2 lesions (p = 0.012 at both 1 and 5 years), presence of new T2 lesions (p = 0.003 and p = 0.028 at 1 and 5 years), and Expanded Disability Status Scale score (p = 0.015 and p = 0.010 at 1 and 5 years) during follow-up. In a univariate Cox regression model, increased EBNA1-specific IgG responses predicted conversion to MS based on McDonald criteria (hazard ratio [95% confidence interval], 2.2 [1.2-4.3]; p = 0.003). Interpretation Our results indicate that elevated immune responses toward EBNA1 are selectively increased in CIS patients and suggest that EBNA1-specific IgG titers could be used as a prognostic marker for disease conversion and disability progression. ANN NEUROL 2010;67:159,169 [source]

Human cytomegalovirus induces a direct inhibitory effect on antigen presentation by monocyte-derived immature dendritic cells

BRITISH JOURNAL OF HAEMATOLOGY, Issue 1 2002
Ulrich Grigoleit
Summary. The hypothesis that productive infection of monocyte-derived immature dendritic cells (DCs) by the human cytomegalovirus (HCMV) is associated with decreased immunostimulatory capacity was tested in this study. DCs were infected with 60,80% efficiency by HCMV strain TB40/E. Infected versus uninfected cells were analysed by fluorescence-activated cell sorting and by immunocytochemistry for surface expression of major histocompatibility complex (MHC) and co-stimulatory molecules as well as cytokine secretion during the 3 d after infection. The immunostimulatory capacity of these cells was measured by mixed leucocyte reaction. In spite of the fact that HCMV infection of DCs induced an increased release of tumour necrosis factor-, (TNF-,) and a decreased interleukin 10 (IL-10) production, expression of MHC class I and II, as well as CD40 and CD80 molecules, were downregulated on infected DCs. The mixed leucocyte reaction showed significantly reduced immunostimulatory capacity of infected DC cultures. Simultaneous detection of MHC antigens and virus antigens by double immunofluorescence revealed that downregulation occurred only on infected cells, but not on uninfected bystander cells. These findings demonstrate on a single cell level, together with the marked downregulation of MHC and co-stimulatory molecules in the presence of high TNF-, and low IL-10 levels, a direct inhibitory effect of HCMV on antigen presentation by immature DCs independent of soluble mediators. [source]