Detection of anti-borna disease virus antibodies from cats in Asian countries, Japan, Philippines and Indonesia using electrochemiluminescence immunoassay.

Anti-Borna disease virus (BDV) antibodies were detected from cats in Japan, Philippines and Indonesia by using electrochemiluminescence immunoassay. Positive rates were 3.1%, 3.8% and 2.0% in Japan, Philippines and Indonesia, respectively. There was no differences in the positive rate of anti-BDV antibodies between male and female cats and among habitats. While, a significantly (P<0.05) higher prevalence (6.5%) was found in the oldest age group (more than 6 years) cats.

A variant of des-gamma-carboxy prothrombin was increased in alcoholic liver disease without hepatocellular carcinoma.

Serum variants of des-gamma-carboxy prothrombin (DCP) recognized by two different monoclonal antibodies, 19B7 and MU-3, were measured in patients with alcoholic liver disease (ALD), and the values were compared with those of viral liver disease (VLD) and hepatocellular carcinoma (HCC). In the assay that used 19B7 antibody, DCP levels in ALD and HCC were significantly higher than that of VLD, although there was no significant difference in the values between ALD and HCC. In the assay that used MU-3 antibody, DCP level of HCC was significantly higher than those of ALD and VLD, although there was no significant difference in values between ALD and VLD. The ratio of 19B7/MU-3 assay values was significantly higher for ALD than the ratios for VLD and HCC. It is suggested that ALD has a different DCP variant pattern compared with VLD and HCC, which suggests that ALD has a different mechanism of DCP production.

[Detection of anti-Borna disease virus antibodies in patients hospitalized in psychiatric hospitals located in the mid-Western region of Poland]. / Przeciwciala prezeciwko wirusowi choroby Borna u pacjentów hospitalizowanych w szpitalach psychiatrycznych na terenach województw lubuskiego i wielkopolskiego.

Borna Disease Virus (BDV) is single stranded RNA virus, which may infect a wide range of animal species. Manifestations of the experimental BDV infection show some resemblance to psychopathological symptoms of mental disorders in humans. Several reports suggest the higher prevalence of anti-BDV antibodies in psychiatric patients than in healthy controls. However, the seroprevalence of anti-BDV antibodies varied due to the different serological methods used in the previous studies. Electrochemiluminescence Immunoassay (ECLIA) is a recently developed, highly specific method of detecting antibodies directed toward two BDV proteins: p24 and p40. We used the ECLIA method for the assessment of seropositivity in 946 psychiatric patients hospitalized in the psychiatric hospitals in the western part of Poland. All patients were clinically diagnosed with ICD-10 criteria. Anti-p40 antibodies have not been found in the studied sample. We found anti p-24 antibodies in 23 cases, which give the seroprevalence rate of 2.4%. This result is consistent with the outcome of Japanese population assessment, done with the same methodology. The seropositive cases did not show diagnostic specificity. We did not find statistically significant gender differences in rate of seropositivity. The seroprevalence of anti-BDV antibodies was not significantly different in patients of urban and rural residence, and in patients of different age groups. This is the first demonstration of anti-BDV antibodies in the Polish population of patients hospitalized in psychiatric hospitals.

Detection of borna disease virus-reactive antibodies from patients with psychiatric disorders and from horses by electrochemiluminescence immunoassay.

The prevalence of Borna disease virus (BDV)-specific antibodies among patients with psychiatric disorders and healthy individuals has varied in several reports using several different serological assay methods. A reliable and specific method for anti-BDV antibodies needs to be developed to clarify the pathological significance of BDV infections in humans. We developed a new electrochemiluminescence immunoassay (ECLIA) for the antibody to BDV that uses two recombinant proteins of BDV, p40 and p24 (full length). Using this ECLIA, we examined 3,476 serum samples from humans with various diseases and 917 sera from blood donors in Japan for the presence of anti-BDV antibodies. By ECLIA, 26 (3.08%) of 845 schizophrenia patients and 9 (3.59%) of 251 patients with mood disorders were seropositive for BDV. Among 323 patients with other psychiatric diseases, 114 with neurological diseases, 75 with chronic fatigue syndrome, 85 human immunodeficiency virus-infected patients, 50 with autoimmune diseases including rheumatoid arthritis and systemic lupus erythematosis and 17 with leprosy, there was no positive case except one case each with alcohol addiction, AIDS, and dementia. Although 19 (1.36%) of 1,393 patients with various ocular diseases, 10 (1.09%) of 917 blood donors, and 3 (4.55%) of 66 multitransfused patients were seropositive for BDV-specific antigen, high levels of seroprevalence in schizophrenia patients and young patients (16 to 59 years old) with mood disorders were statistically significant. The immunoreactivity of seropositive sera could be verified for specificity by blocking with soluble p40 and/or p24 recombinant protein. Anti-p24 antibody was more frequent than p40 antibody in most cases, and in some psychotic patients antibody profiles showed only p40 antibody. Although serum positive for both p40 and p24 antibodies was not found in this study, the p40 ECLIA count in schizophrenia patients was higher than that of blood donors. Furthermore, we examined 90 sera from Japanese feral horses. Antibody profiles of control human samples are similar to that of naturally BDV-infected feral horses. We concluded that BDV infection was associated in some way with psychiatric disorders.

Increase of serum des-gamma-carboxy prothrombin in alcoholic liver disease without hepatocellular carcinoma.

The purpose of this study is to determine serum des-gamma-carboxy prothrombin (DCP) levels in benign liver diseases by a new sensitive method, and to demonstrate the elevation of serum DCP in alcoholic liver disease (ALD) without hepatocellular carcinoma (HCC). Median values of serum DCP were 16.2 mAU/ml (range: 3.2 to 1570 mAU/ml) in ALD and 16.7 mAU/ml (1.2 to 75.4 mAU/ml) in viral liver disease (VLD). Using the cut-off value of 40 mAU/ml as a tumor marker for HCC, 21% (11/52) was positive in ALD and 2% (1/57) was positive in VLD (p = 0.0014, Fisher's exact probability test), and 27% (9/33) was positive in alcoholic liver cirrhosis and 3% (1/39) was positive in viral liver cirrhosis (p = 0.0042, Fisher's exact probability test). The positive rate of DCP was significantly (p < 0.001, Spearman's rank correlation test) correlated with the severity of liver disease in ALD. Serum vitamin K level was not decreased in cases with ALD. In a demonstrable case, serum DCP was decreased after abstinence and was increased again after the beginning of ethanol intake, suggesting the involvement of ethanol to the elevation of serum DCP in ALD. In conclusion, serum DCP was significantly elevated in ALD, compared with VLD, although the mechanism of the elevation of DCP was not clarified. Ethanol intake may act, in part, on the increase of serum DCP in ALD.

Measurement of serum levels of des-gamma-carboxy prothrombin in patients with hepatocellular carcinoma by a revised enzyme immunoassay kit with increased sensitivity.

BACKGROUND: Des-gamma-carboxy prothrombin (DCP) is a useful tumor marker for hepatocellular carcinoma (HCC). The conventional enzyme immunoassay (EIA) kit for DCP lacks adequate sensitivity to detect small HCC. Thus, a revised EIA kit for DCP has been developed. In this revised DCP kit, the blank value has been reduced, making it now possible to obtain a normal value. The authors used this revised EIA kit for DCP with increased sensitivity and evaluated its usefulness as a tumor marker for HCC. METHODS: Serum DCP and alpha-fetoprotein (AFP) levels were determined in 60 patients with HCC, 60 with cirrhosis, 57 with chronic hepatitis, and 273 normal subjects. The cutoff value for the revised DCP kit was determined to be 40 mAU/mL, and the values for the conventional DCP kit and AFP were 100 mAU/mL (0.1 AU/mL) and 20 ng/mL, respectively. RESULTS: The mean DCP value was 17.5 mAU/mL in the normal subjects, and the detection limit was 10 mAU/mL for this revised DCP kit. The positivity rate for DCP in patients with HCC was 60% by the revised DCP kit, in contrast to 40% by the conventional DCP kit. The sensitivity, specificity, and accuracy of the revised kit were 60%, 92.3%, and 81.4%, respectively, whereas those of the conventional kit were 40%, 98.3%, and 78.5%. Thirty-five percent of HCC tumors smaller than 2 cm and 78.1% of those larger than 3 cm were positive for DCP by the revised kit. The corresponding figures were 20% and 56.3% with the conventional kit. Twelve (33.3%) of the 36 HCC patients who were negative for DCP by the conventional kit were positive by the revised kit. When the revised DCP kit was used in combination with AFP, 86.7% of the HCC patients and 78.3% of the patients with solitary HCC were positive for at least 1 of these markers. CONCLUSIONS: The revised DCP kit is more useful than the conventional DCP kit as a tumor marker for HCC and should be used in combination with AFP.

The effect of IL-6 on the des-gamma-carboxy prothrombin synthesis in human hepatoma cells.

Effects of several cytokines on des-gamma-carboxy prothrombin (PIVKA II) synthesis in human hepatoma cells were investigated to know the process of PIVKA II production during a liver allograft rejection. Human recombinant interleukin-6 (IL-6) significantly stimulated the PIVKA II synthesis without any influence on the cell proliferation. The effect was almost completely neutralized by the specific anti-IL-6 antibody. Neither tumor necrosis factor (TNF), interleukin-1 (IL-1) nor interferon-gamma (IFN-gamma) had such a stimulative effect. IL-6 appears to stimulate PIVKA II production, and would be a candidate of factors that enhance the production of PIVKA II during a liver allograft rejection.

Chemical modification of gamma-carboxyglutamic acid residues in prothrombin elicits a conformation similar to that of abnormal (des-gamma-carboxy)prothrombin.

Chemical modification of gamma-carboxyglutamic acid (Gla) residues in human prothrombin to gamma-methyleneglutamic acid (gamma-MGlu) residues elicited a conformation similar, if not identical, to that of des-gamma-carboxy prothrombin or PIVKA-II, i.e., prothrombin molecules induced by vitamin K antagonists or vitamin K deficiency states. The reaction seems to proceed sequentially by preferentially modifying a Gla at residue 32 that is located innermost among 10 Gla residues of human prothrombin. The initial modification resulted in nearly 50% losses of barium salt adsorption, the procoagulant activity and thrombin generation by the prothrombinase complex. The subsequent modification of two Gla residues at positions 6 and 16 gave rise to the immunoreactivity to an established monoclonal antibody that specifically recognizes the des-gamma-carboxy prothrombin. Further modification of Gla residues increased the reactivity to the antibody, indicating that the conformation recognized by the antibody was stabilized so as to more readily fit the recognition site of the antibody. The appearance of the immunoreactivity was obviously related to the modification of Gla residues in prothrombin, since all other similarly treated derivatives of prothrombin lacking the Gla-domain failed to react with the antibody. Such chemically modified prothrombins may serve as models for studying abnormal des-gamma-carboxy prothrombin produced in vitamin K deficiency states.