Prevalence of antibodies to hepatitis C virus (HCV) in haemophiliacs

The prevalence of 1) hepatitis C virus (HCV), an agent likely to be responsible for parenterally transmitted hepatitis non-A, non-B, 2) hepatitis B virus (HBV) and 3) human immunodeficiency virus (HIV) infection was studied in 211 patients with clotting disorders (78% of the patients had residual factor activities of less than or equal to 2%). Of these patients 71% were positive for HBV markers and 44% for HIV markers. Using a new ELISA technique, 80% were anti-HCV-positive. The prevalence of anti-HCV was greater in patients with more severe clotting disorders and was related to the total amount of replacement therapy received; the prevalence was less in older patients. Seroconversion after a single exposure to dry heat-treated factor concentrates was documented in 3 patients 3-4 months after exposure.     

AIDS risk and prevention in transfusions

Transfusion of blood and blood products range from 2 to 8% of the cases of AIDS. The identification of HIV viral agent and the appearance of tests designed to detect antibodies associated with mechanisms of autologous transfusions and inactivation of virus of clotting factors concentrates have contributed to decrease this mean of transmission. Some aspects such as the difference of sensitivity in the tests, immunologic windows, and the appearance of new viruses such as the HIV 2 increase the complexity of the problem. Therefore, the services of hemotherapy all over the world must be aware of mechanisms of exclusion of potentially infected donors, in addition to education, and, mainly, the development of new techniques that can guarantee transfusion safety.     

Prevalence and specificity of some rare red cell pan-reactive alloantibodies against high frequency red cell antigens among hospitalized Saudi patients

Some patients'' sera react with all available donors'' red cells and a compatible donor is difficult or impossible to be found. These may either be due to a complex mixture of antibodies or the presence of alloantibodies against high-frequency antigens (HFAs). The aim of this study is to identify the prevalence and characteristics of antibodies to HFAs in Saudi Arabian patients. A total of 23 out of 172 000 patients who received blood transfusions had rare alloantibodies to HFAs at an incidence of 0.013%. Twenty-three patients suspected with pan-reactive alloantibodies against HFAs had their red cells tested using antisera to HFAs, while their plasma was tested against a selected panel of red blood cells with rare phenotypes. Anti-Ge2 antibody was found in the highest number of patients (56.5%), whereas anti-U, anti JK3, anti H, anti-RH 29, anti-hr^s, anti-Kn^a, anti-Ch, anti-Rg, anti-Yt^a, and anti-Cr^a antibodies were found in the remaining patients (43.5%). This study suggests that although antibodies such as anti-Ge2, anti- Kn^a, anti-Ch, anti-Rg, anti-Yt^a , and anti-Cr^a are not clinically significant, they cause a delay in the provision of compatible blood. Whereas, anti-U, anti JK3, anti H, anti-RH29 and anti-hr^s are clinically significant antibodies. An understanding of antibody characteristics to HFAs and the widespread use of the extended red cell phenotype and antibody identification panel will both be helpful for the diagnosis of these HFAs.     

Immunomanipulation of Appetite and Body Temperature through the Functional Mimicry of Leptin

Objective: Although current obesity therapies produce some benefits, there is a need for new strategies to treat obesity. A novel proposal is the use of anti‐idiotypic antibodies as surrogate ligands or hormones. These anti‐idiotypic antibodies carry an internal motif that imitates or mimics an epitope in the antigen (i.e., hormone or ligand). Thus, anti‐idiotypic antibodies to several ligands may mimic them in transducing signals when binding to their receptors. Research Methods and Procedures: We developed an anti‐idiotypic polyclonal antibody against the region of a leptin monoclonal antibody that competitively binds leptin, mimicking the active site structure of leptin. To test whether our anti‐idiotype could also reproduce leptin functions, we examined food intake, body weight, and colonic temperature in male Wistar rats (n = 9) in response to intracerebroventricular administration of the leptin anti‐idiotype. Results: Our leptin anti‐idiotype induced a significant reduction in food intake coupled with an increase in body temperature comparable to that of leptin. That is, the intracerebroventricular administration of 8.0 μg of leptin anti‐idiotype or 5.0 μg leptin significantly increased colonic temperature (Δ 1.9 ± 0.11 °C and Δ1.7 ± 0.12 °C, respectively). In addition, both decreased 24‐hour food intake (?26.4 ± 2.4% and ?21.9 ± 2.2%) compared with the control. The gain in body weight was also decreased by acute administration of the anti‐idiotype (?1.4 ± 0.28%) and leptin (?1.1 ± 0.17%) vs. the phosphate‐buffered saline control (1.3 ± 0.15%). Discussion: These studies revealed that the leptin anti‐idiotype inhibited food intake and enhanced heat production, mimicking leptin's central actions.     

Study of serological and biological markers in viral hepatitis. 157 hemophiliacs

We observed for a two years period 157 hemophiliacs (138 with hemophilia A whose 13 were severe and 19 with hemophilia B whose 13 were severe) and we studied the incidence of liver dysfunction and the role played by HB and non-A, non-B, viruses. Whereas 32 patients not related had no evidence of serological HB virus markers (by radioimmunoassay), 88 (70,4 %) among the 135 hemophiliacs with large or small exposure to blood products were "HB positive". 90,9 % were positive for anti-HBs and anti-HBc antibodies and only two patients had persistent antigenemia. These results appeared independent of the kind of treatment (factor VIII or factor IX concentrates). Six among 17 children born since 1974, when the antigen was detected by RIA, had the serological HB virus markers, showing that this method is not sufficient to completely eliminate the HB virus. However the amount of viruses injected is too small to induce an acute hepatitis and rather produces specific antibodies which protect hemophiliacs against reinfection. An elevated level of serum transaminases (SGPT) was observed in 9,4 % of non treated hemophiliacs, 15,1 % of treated hemophiliacs with no serological markers of HB virus and 27,7 % of treated hemophiliacs "HB positive". This shows that the use of concentrates and the occurring of HB virus in the patients are not the only factors producing liver dysfunction. The role of non-A, non-B viruses has been recognized in 7 patients out of 9 with transient elevation of serum transaminase levels, by Trepo with an immunodiffusion technique.     

Immune responses of the common seal (Phoca vitulina) to canine distemper antigens during an outbreak of phocid distemper viral infection

In 1988, there was a marked increase in the mortality rate of the common seal ( Phoca vitulina ) in European waters which was shown to be associated with a canine distemper-like virus (CDV), recently named Phocid Distemper Virus (Cosby et al. , 1988). Investigations were carried out to determine the ability of common seals to respond immunologically and to determine the levels of antibody produced. Common seal immunoglobulins were purified, analysed and shown to be similar to those of other mammals. A simple immunoassay to measure seal antibodies to CDV was developed and showed striking differences between the susceptible seals (low levels of antibodies) and the surviving common seals (high amounts of anti-distemper antibodies). Similar results were obtained with a neutralization test currently used to measure antibody titres to canine distemper virus in the dog. The adult common seals had high antibody titres and may be protected for future years, whereas the younger seals did not develop high levels of antibodies. This may be because either the younger seals had not encountered the virus or had not developed effective immunity.     

献血员抗－HCV检测报告

对１５８７名献血员进行了抗－ＨＣＶ检测,总阳性率５．６０％,在不同职业中农民较高,占６．７２％,３０岁以上为１２．７６％。我站自改进采浆工艺,严格使用一次性消毒器具后,未发现ＨＣＶ交叉感染。职业献血者抗－ＨＣＶ阳性率高达３５．４８％,易造成输血后ＨＣＶ感染。对ＨＣＶ感染ＯＤ值阳性３０人又进行４－６个月的观察复测,其中１６人ＯＤ值下降,６人上升,认为ＯＤ值的变化与自限性ＨＣＶ感染有关。     

献血员抗－HCV检测报告

对１５８７名献血员进行了抗－ＨＣＶ检测,总阳性率５．６０％,在不同职业中农民较高,占６．７２％,３０岁以上为１２．７６％。我站自改进采浆工艺,严格使用一次性消毒器具后,未发现ＨＣＶ交叉感染。职业献血者抗－ＨＣＶ阳性率高达３５．４８％,易造成输血后ＨＣＶ感染。对ＨＣＶ感染ＯＤ值阳性３０人又进行４－６个月的观察复测,其中１６人ＯＤ值下降,６人上升,认为ＯＤ值的变化与自限性ＨＣＶ感染有关。     

HIV-specific IgA antibodies in tears of children with aids or at risk of AIDS

To improve on the diagnosis of human immunodeficiency virus (HIV) infection, 14 children with clinical evidence of AIDS, 86 children less than 15 months old and born to seropositive mothers, and 29 controls were tested for the presence of IgA antibody in tears directed against HIV antigens on Western blots. IgA antibodies in tears against env- and pol-encoded proteins were present in 13 of 14 children with AIDS and in 13 of 86 children born to seropositive mothers. No HIV-specific IgA was observed in tears of the 29 controls. Among the 86 children less than 15 months old, 11 had clinical evidence of AIDS and 7 of them (64%) had HIV-specific IgA in tears. Results show that the demonstration of lacrimal HIV-specific IgA may help to distinguish between truly infected children and those whose HIV antibodies are passively transferred from the mother. Therefore, this simple method is a good tool for laboratory diagnosis of paediatric AIDS.     

A serosurvey of viral infections in lions (Panthera leo), from Queen Elizabeth National Park, Uganda

Serum samples from 14 lions (Panthera leo) from Queen Elizabeth National Park, Uganda, were collected during 1998 and 1999 to determine infectious disease exposure in this threatened population. Sera were analyzed for antibodies against feline immunodeficiency virus (FIV), feline calicivirus (FCV), feline herpesvirus 1 (feline rhinotracheitis: FHV1), feline/canine parvovirus (FPV/CPV), feline infectious peritonitis virus (feline coronavirus: FIPV), and canine distemper virus (CDV) or for the presence of feline leukemia virus (FeLV) antigens. Ten lions (71%) had antibodies against FIV, 11 (79%) had antibodies against CDV, 11 (79%) had antibodies against FCV, nine (64%) had antibodies against FHV1, and five (36%) had antibodies against FPV. Two of the 11 CDV-seropositive lions were subadults, indicating recent exposure of this population to CDV or a CDV-like virus. No lions had evidence of exposure to FeLV or FIPV. These results indicate that this endangered population has extensive exposure to common feline and canine viruses.     

Development of immunohistochemistry and enzyme-linked immunosorbent assays for the detection of circulating antibodies against Enteromyxum scophthalmi (Myxozoa) in turbot (Scophthalmus maximus L.)

Immunohistochemistry and enzyme-linked immunosorbent assays were developed for the detection of specific antibodies against the myxosporean parasite Enteromyxum scophthalmi in turbot (Scophthalmus maximus L.). Fish which had survived a previous epizootic were exposed to the parasite by cohabitation with infected animals, and 83 days later the plasma was tested for the presence of antibodies. Plasma of non-exposed fish was used as negative control. Immunohistochemistry (IHC) using rabbit anti-turbot IgM antibody was first used to detect these antibodies, and to study to which parasite structures they were directed against. Also, an antibody-ELISA using whole cell lysates of the parasite as antigen, and a monoclonal antibody anti-turbot IgM, was developed. All the exposed fish were found to have specific antibodies against the parasite, and none of them developed signs of disease or died during the experiment. Primary cells were the main parasite stage immunolabelled, and the staining was distinctly located on the cytoplasm and the cytoplasmic membrane. IHC was more sensitive than ELISA, as the endpoint was two to four fold higher with the former technique. Although there was great individual variation, the antibody titres found can be considered high, reaching up to 1:32,000 with ELISA and 1:64,000 with IHC. The results suggest that turbot showing acquired immunity against E. scophthalmi, could develop resistance against new infections.     

Immunological regression of metastatic cancer in the liver as a result of “in vivo xenogenization”

We attempted to induce the regression of liver metastatic tumor cellsin vivo by the administration to rats of Friend leukemia virus (FV) (in vivo xenogenization). The virus which was used in this experiment, FV, is highly immunogenic and does not normally cause disease in an adult rat. At first, we induced a FV viremia in tumor bearing rats in order to deliver the virus to the site of the tumor cells. FV viremia was induced by injecting 60 mg/kg cyclophosphamide (CY) i.v. after the administration of FV, and by transferring syngeneic bone marrow cells so that FV would be able to infect them and then replicate.In order that the tumor cells which were infected with virus should regress, it was necessary to break down their tolerance to FV antigens. As adoptive immunotherapy we therefore, transferred syngeneic spleen cells from rats which had been immunized with FV to tumor bearing rats. The result of this experiment was that these tumor bearing rats infected with FV which had received either normal syngeneic spleen cells or no spleen cells as controls died from liver metastasis (8 out of 9 rats (89%) and 15 out of 17 (88%) respectively). On the other hand, only 4 out of the 15 (27%) tumor bearing rats which were infected with FV and which received FV-immune spleen cells died from liver metastasis.These sets of data indicate that thein vivo xenogenization of tumor cells are indeed able to induce the regression of metastic tumor cells.     

Safety studies of the oral rabies vaccine SAD B19 in striped skunk (Mephitis mephitis)

Safety of the modified live rabies virus vaccine, SAD B19, was studied in striped skunks (Mephitis mephitis). Seven skunks received 10(7.9) foci formatting units by direct oral administration. In four cages, a vaccinated animal was placed with a control animal, the other three vaccinated skunks were housed individually. Saliva and nasal swabs were collected 1, 2, 4, 24, 48, and 72 hr post-vaccination. From all vaccinated and control animals (n = 11) blood samples were collected 0, 28, 56, 84, and 296 days post-vaccination. Three of seven vaccinated skunks seroconverted. None of the control animals had detectable levels of rabies virus neutralizing antibodies. Also no vaccine virus was isolated from the nasal and saliva swabs collected from any animal. Thus, SAD B19 was innocuous for skunks in our study after direct oral administration at field concentration.     

HIV transmission to patients with hemophilia by heat-treated,donor-screened factor concentrate.

Six hemophilia patients previously seronegative for human immunodeficiency virus (HIV) seroconverted between September 1986 and September 1987. None had risk factors for HIV infection other than hemophilia. We compared the factor concentrates received by these patients with the concentrates received by 10 seronegative hemophilia patients. A statistically significant association was observed between seropositivity and the receipt of two lots of Factor VIII produced from the same plasma pool (odds ratio 77, p = 0.0014); five of the six case subjects but none of the control subjects had received concentrate from one of the two lots. Available evidence suggests that the sixth case subject had also received concentrate from an implicated lot. Symptoms including rash and fever were reported in five cases within 6 weeks after the implicated concentrate had been given. The implicated lots were produced from plasma from paid donors that had been screened and then heated at 60 degrees C for 30 hours in the lyophilized state. Subsequent to our investigation all concentrate produced by this process was removed from distribution.     

IgG-antibodies to HTLV-III in patients with AIDS, LAS, and persons at risk of AIDS in West Germany

In a first seroepidemiological study on the prevalence of the human T-lymphotropic retrovirus HTLV-III in West Germany, sera of 26 patients with acquired immunodeficiency syndrome (AIDS), 33 patients with lymphadenopathy syndrome (LAS) or AIDS related complex (ARC), and 113 homosexual men at risk of AIDS were screened for IgG antibodies to HTLV-III by an enzyme linked immunosorbent assay (ELISA). 22 out of 26 AIDS-patients (84.6%), 24 out of 33 LAS-patients (72.7%), and 44 out of 113 healthy homosexual men with increased risk of AIDS (38.9%) were found positive for antibodies to HTLV-III. Heterosexual controls including healthy laboratory workers and medical personnel with contact to AIDS patients did not show antibodies to HTLV-III. The HTLV-III antibodies analyzed predominantly recognize a protein of molecular weight 41,000 (p41).     

Specific antibodies to viruses HL-23 and BILN in the blood plasma of patients with acute myelogenous leukaemia and with potential preleukaemia

Blood plasma samples from patients with acute myelogenous leukaemia (AML) or potential preleukaemia and from control subjects were tested for antibodies to the viruses HL-23 and BILN by membrane immunofluorescence. Of 15 patients with untreated AML, three, each having a low peripheral leucocyte count at the time of sampling, had detectable antibodies. Antibodies were present in the plasma of 5 out of 8 AML patients being in remission as a result of chemotherapy. In these cases, the antibody levels significantly exceeded those demonstrated in the untreated cases. Of 12 patients with potential preleukaemia, five proved to be positive. Of the 7 antibody-negative patients, four developed manifest leukaemia within 12-18 months after the first testing. The results are suggestive of a favourable prognostic role of the presence of the antibodies under study. In the majority of the antibody-positive AML and potential preleukameia cases antibodies were detectable to both components of the HL-23 virus. Of 30 control subjects, three had demonstrable antibodies to the BILN virus.     

Serological Detection of Grapevine leafroll virus 2 Using an Antiserum Developed against the Recombinant Coat Protein†

Grapevine leafroll associated virus 2 (GLRaV 2) is one of the important components in the leafroll disease complex. The coat protein gene of GLRaV 2 was cloned into a protein expression vector pMAL‐c2x and the recombinant protein, consisting of the maltose binding protein (MBP) and GLRaV 2 coat protein (CP), was expressed in Escherichia coli. The recombinant MBP‐CP was used to raise a high quality antiserum. When used in Western blot analysis, the anti‐MBP‐CP antiserum produced specific reaction to the recombinant protein as well as to the viral coat protein of GLRaV 2. In Immunosorbent electron microscopy study, the anti‐MBP‐CP antibodies strongly decorated the GLRaV 2 virions. Using the newly developed antiserum, an indirect plate‐trapped antigen enzyme‐linked immunosorbent assay method was developed and successfully implemented for virus detection. A field survey was conducted to evaluate the virus infection status by GLRaV 2 and GLRaV 3 using antibodies developed against their respective recombinant coat proteins.     

Deposition of fibronectin on material surfaces exposed to plasma: quantitative and biological studies

Experiments were carried out to characterize plasma fibronectin deposition onto material surfaces exposed to plasma solutions. Under nonclotting conditions, the amount of fibronectin adsorption on the surfaces, determined by an indirect radioactive antibody assay, was maximal at low plasma concentrations (0.1%). At higher concentrations of plasma, other plasma proteins appeared to compete with and inhibit adsorption of fibronectin. Biological activity (fibronectin-promoted cell spreading) was also greatest at low plasma concentrations and decreased as the plasma concentration was raised. When surfaces were exposed to plasma under clotting conditions (i.e., addition of Ca2+ and thrombin), fibronectin deposition on the surfaces and biological activity remained constant or increased as the plasma concentration was raised. Based on indirect immunofluorescent antibody assays, the fibronectin deposited from clotting plasma appeared to be in a punctate distribution over the entire material surface and occasionally was associated with discrete fibrillar structures. The increased deposition of fibronectin from clotting plasma compared to nonclotting plasma (approximately a 10-fold difference with 10% plasma) was partially a result of covalent crosslinking of fibronectin to fibrin based upon studies with putrescine added to inhibit crosslinking during clotting. On the other hand, the increase in biological activity that occurred if the surfaces were exposed to clotting plasma was completely inhibited by putrescine, indicating that fibronectin had to be crosslinked to fibrin to have biological activity under these conditions. Finally, fibronectin deposition also occurred on surfaces exposed to whole blood and was markedly enhanced when clotting occurred.     

AIDS and haemophilia: morbidity and morality in a well defined population.

One hundred and forty-three multitransfused patients with hereditary haemostatic disorders were examined for evidence of disease related to the acquired immune deficiency syndrome (AIDS). Ninety-nine patients with severe haemophilia A were tested for anti-HTLV-III and 76 were found to be positive. All except one of these seropositive patients had received commercial factor VIII concentrates at some time. Eighteen patients with haemophilia B were tested and all were anti-HTLV-III negative. Three out of 36 sexual partners of patients with haemophilia A positive for anti-HTLV-III were also seropositive. One, who had recently received blood transfusions, had AIDS with Pneumocystis carinii pneumonia. Three patients with severe haemophilia A died from Aids. A further 30 haemophiliacs had AIDS related complex or lymphadenopathy that could be related to HTLV-III infection. There was a significant correlation between lymphadenopathy and anti-HTLV-III seropositivity. No evidence of casual spread of AIDS was found since all 68 health care staff tested were anti-HTLV-III negative, including three surgeons who regularly worked with patients positive for anti-HTLV-III. The resources devoted to counselling and laboratory support in centres treating people at risk and their families need to be urgently reassessed.     

Dry-heat treatment process for enhancing viral safety of an antihemophilic factor VIII concentrate prepared from human plasma

Viral safety is a prerequisite for manufacturing clinical antihemophilic factor VIII concentrates from human plasma. With particular regard to the hepatitis A virus (HAV), a terminal dry-heat treatment (100 degrees for 30 min) process, following lyophilization, was developed to improve the virus safety of a solvent/detergent-treated antihemophilic factor VIII concentrate. The loss of factor VIII activity during dry-heat treatment was of about 5%. No substantial changes were observed in the physical and biochemical characteristics of the dry-heat-treated factor VIII compared with those of the factor VIII before dry-heat treatment. The dry-heat-treated factor VIII was stable for up to 24 months at 4oC. The dry-heat treatment after lyophilization was an effective process for inactivating viruses. The HAV, murine encephalomyocarditis virus (EMCV), and human immunodeficiency virus (HIV) were completely inactivated to below detectable levels within 10 min of the dry-heat treatment. Bovine herpes virus (BHV) and bovine viral diarrhea virus (BVDV) were potentially sensitive to the treatment. However porcine parvovirus (PPV) was slightly resistant to the treatment. The log reduction factors achieved during lyophilization and dry-heat treatment were > or =5.55 for HAV, > or =5.87 for EMCV, > or =5.15 for HIV, 6.13 for BHV, 4.46 for BVDV, and 1.90 for PPV. These results indicate that dry-heat treatment improves the virus safety of factor VIII concentrates, without destroying the activity. Moreover, the treatment represents an effective measure for the inactivation of non-lipid-enveloped viruses, in particular HAV, which is resistant to solvent/detergent treatment.