Biomedical subjects
U Bienzle
Publications and source records attributed to U Bienzle.
Immunity against diphtheria in blood donors in East Berlin and West Berlin.
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Hepatitis G virus RNA and hepatitis G virus antibodies in renal transplant recipients: prevalence and risk factors.
BACKGROUND: Hepatitis G virus (HGV/GBV-C) RNA indicating current infection has been frequently isolated from the sera of transplant recipients and other multitransfused individuals. Lifetime exposure to the virus, however, is unknown. We carried out a study to determine the prevalence and risk factors of HGV antibodies and of HGV RNA among renal transplant recipients, and to investigate possible associations between HGV RNA and immunosuppressive treatment. METHODS: HGV RNA was detected by reverse transcriptase-polymerase chain reaction, and HGV antibodies (anti-E2) by a newly developed immunoassay. To assess risk factors for HGV exposure, univariate and multivariate analysis was performed. RESULTS: Of the 221 patients, 14% were HGV RNA positive and 40% had HGV antibodies. Both HGV RNA and anti-HGV were present in only two individuals. Thus, the overall HGV exposure prevalence was 53%. It increased significantly with the number of blood transfusions. In logistic regression, the adjusted HGV exposure prevalence odds ratio was 5.7 (95% confidence interval [CI]: 2.2-15) among patients with > or =10 transfusions (baseline: no transfusions). Other independent risk factors were a longer duration of hemodialysis and a longer time interval since transplantation. HGV viremia was not associated with the type of immunosuppressive treatment. Alanine aminotransferase levels were not significantly increased among HGV RNA-positive patients. CONCLUSIONS: Much higher proportions of renal transplant recipients were exposed to HGV than is suggested by HGV RNA detection alone. The majority of infected individuals apparently eliminate the virus over time. Contaminated blood transfusions have to be regarded as a main risk factor for HGV infection.
Routine immunizations in adult renal transplant recipients.
BACKGROUND: Vaccination guidelines for transplant recipients include regular boosters of tetanus, diphtheria, and inactivated polio vaccine, but there are few published data on the efficacy of these vaccines in patients receiving immunosuppressive therapy. METHODS: Serum antibody values were evaluated before and 4 weeks after tetanus, diphtheria, and inactivated polio vaccination in 164 renal transplant recipients compared with healthy controls. Twelve months later, antibody levels were evaluated in 55 patients. RESULTS: Prebooster tetanus antitoxin values were lower in transplant recipients than in controls. All patients developed protective tetanus antibody levels (> or = 0.01 IU/ml) after vaccination. After 12 months, serum antibodies had decreased, but all patients maintained protective values. Diphtheria antitoxin titers before and after booster vaccination were lower in patients than in controls: 88.5% of patients and 96.2% of controls developed protective diphtheria antibody values. Twelve months after vaccination, diphtheria antitoxin values were below the protective level (0.1 IU/ml) in 38% of patients. Prebooster antibody values to poliovirus types 1 and 3 were comparable in patients and controls, whereas antibodies to poliovirus type 2 were lower in transplant recipients. Seroprotection rates and geometric mean antibody titers after vaccination were equivalent between the two groups for all three poliovirus types. No difference was observed in antibody levels between patients on different immunosuppressive drug regimens. Adverse reactions were significantly less often reported by transplant recipients. CONCLUSIONS: In transplant recipients, tetanus and inactivated polio vaccinations are well tolerated and induce protective antibody levels; diphtheria vaccination as currently recommended is less effective and protective antitoxin values decrease rapidly in these patients within 1 year after vaccination.
Intravenous or intramuscular anti-HBs immunoglobulin for the prevention of hepatitis B reinfection after orthotopic liver transplantation.
To prevent reinfection with hepatitis B virus after orthotopic liver transplantation, patients receive long-term intravenous anti-HBs immunoprophylaxis. We compared the pharmacokinetics of intravenously and intramuscularly administered commercially available hepatitis B virus immunoglobulins. The study group consisted of 12 patients on immunoprophylaxis after orthotopic liver transplantation, who were Hbs antigen negative; 11 were anti-HBe positive and one was HBe positive. The patients first received intravenous immunoglobulin, and six of them were then transferred to intramuscular immunoglobulin. Our findings show that with fortnightly intramuscular application of 1000 IU of anti-HBs, reproducible and stable antibody titers above 100 IU of anti-HBs can be achieved. Side effects of intramuscular immunoprophylaxis are minimal and the method is safe. The switch from intravenous (1500 IU of anti-HBs) to intramuscular (1000 IU of anti-HBs) reduced the cost of immunoprophylaxis by more than 50%.
Aberrant atrioventricular conduction triggered by antimalarial prophylaxis with mefloquine.
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History of syringe sharing in prison and risk of hepatitis B virus, hepatitis C virus, and human immunodeficiency virus infection among injecting drug users in Berlin.
BACKGROUND: Injecting drug users (IDU) are at risk of parenterally transmitted diseases such as hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) infection. We investigated whether a history of syringe sharing in prison is a risk factor for these infections. In the longitudinal part of the study, HBV, HCV, and HIV seroincidence rates were determined. METHODS: The participants were recruited by multisite-sampling at different agencies for IDU. Data on risk behaviour were obtained by a standardized questionnaire. Serological markers for HBV, HCV, and HIV were determined. Logistic regression analysis was performed to adjust for confounding effects. RESULTS: A history of syringe sharing in prison was significantly associated with HBV (adjusted prevalence odds ratio [POR] = 3.9, 95% confidence interval [CI]: 2-10), HCV (POR = 9.7, 95% CI: 3-33), and HIV infection (POR = 10.4, 95% CI: 4-29). The HIV seroincidence rate was 5.9 per 100 person-years. None of the IDU receiving methadone maintenance treatment (MMT) seroconverted whereas the HIV incidence was 8.5 among IDU not in MMT (P = 0.01). CONCLUSIONS: The increased risk of HBV, HCV, and HIV infection among IDU who had shared syringes in prison warrants specific preventive action. The longitudinal data suggest that IDU in MMT have a lower risk of HIV infection.
HLA DRB1-DQA1-DQB1 haplotype diversity in two African populations.
HLA class II DRB1-DQA1-DQB1 haplotypic polymorphism was determined in 120 Liberian and 230 Gabonese individuals. In our study groups, the number of allelic variants observed for each locus was similar to that found in non-African populations. However, 39 novel haplotypes and several yet unrecognized DRB1-DQA1 and DQA1-DQB1 combinations were identified. The extent of HLA-haplotypic variability in Africans appears to result from the high degree of allele combinations rather than from allelic polymorphism.
Malaria Chemoprophylaxis in German Tourists: A Prospective Study on Compliance and Adverse Reactions.
Background: The number of tourists visiting malaria endemic regions is continuously increasing. The risk of aquiring malaria infection can largely be prevented by the regular use of chemoprophylactic drugs combined with using protective measures against mosquito bites. In a prospective study we wished to determine the tolerability of chemoprophylactic drugs and the factors that influence compliance with malaria chemoprophylaxis and antimosquito measures. Method: German travelers (n = 6504) who attended the Berlin Institute of Tropical Medicine in Berlin for pretravel medical advice were interviewed by phone 4 weeks after their journeys about compliance with the recommended malaria chemoprophylaxis and the incidence of side effects. Results: Compliance was better with mefloquine (94.5%) than with chloroquine (85.9%) (p<.001) or chloroquine plus proguanil (79.8%) (p<.001). Compliance was influenced by the purpose of travel, duration of stay, places of stay, and adverse reactions. Side effects occurred in 20.6% of the travelers who took chemoprophylactic drugs. There was no significant difference in the incidence of side effects between the three drug regimens, but people who took mefloquine more often reported neuropsychiatric reactions (6.5% versus 3.9% with chloroquine and 3.6% with chloroquine and proguanil; p<.001)). Side effects were usually mild to moderate and in no instance required hospitalization. People who took their drugs with meals less often reported side effects (15.2%) (p<.01). Conclusion: The knowledge of user profiles (and particular factors that presage side effects and noncompliance) may help us to improve pretravel counseling, thereby reducing the risk that travelers may acquire malaria infection.
Determinants of current HIV risk behaviour among injecting drug users in Warsaw, Poland.
Of the injecting drug users (IDUs), 24% had borrowed, and 37% had passed on syringes in the previous 6 months. In logistic regression analysis, current borrowing of syringes was significantly associated with a shorter duration of injecting drug use, a higher number of drug-injecting sex partners in the previous 6 months, and with current lending of syringes. A majority of the IDUs have modified previous HIV risk behaviour but these modifications are insufficient and not sustained over time. Intensified AIDS prevention measures for IDUs in Poland are needed.
Immunogenicity of an inactivated hepatitis A vaccine administered according to two different schedules and the interference of other "travellers" vaccines with the immune response.
A total of 2036 persons consulting vaccination centers in Germany were vaccinated with an inactivated hepatitis A vaccine (containing 720 ELISA units of antigen) either according to the standard schedule (two vaccinations given 4 weeks apart) or to an abbreviated schedule (two vaccinations given 2 weeks apart) in a controlled clinical study. The abbreviated schedule induced a similar rate of seroconversion and geometric mean antibody titre as compared to the standard schedule. The incidence of reactions reported after vaccination was similar in both groups. When other "travellers" vaccines were given simultaneously neither the immunogenicity nor the reactogenicity of the hepatitis A vaccine were influenced. These findings have considerable practical importance in the prevention of hepatitis A in travellers.
Autochthonous cutaneous larva migrans in Germany.
Cutaneous larva migrans syndrome is extremely rare in Germany. However, three cases of this syndrome were diagnosed in patients from Berlin, Germany, in the summer of 1994. Exposure to the infective agent in endemic areas and close contact with animals were excluded. It is assumed that the extreme temperatures in summer 1994 favoured the conditions of infection.
Detection of the hepatitis G virus genome among injecting drug users, homosexual and bisexual men, and blood donors.
The recently identified hepatitis G virus (HGV) is parenterally transmitted; the impact of sexual transmission is unknown. Moreover, it is unclear what proportion of HGV-infected persons may develop persistent viremia. Sera from injecting drug users (IDUs), non-drug-injecting homosexual and bisexual men with high levels of sexual risk behavior, and blood donors were tested for HGV RNA and hepatitis C virus (HCV) RNA by reverse transcriptase-polymerase chain reaction and for antibodies to human immunodeficiency virus, hepatitis B virus, and HCV. HGV RNA was detected in 33% of IDUs (n = 130), 11% of homosexual and bisexual men (n = 101), and 2% of blood donors (n = 90). HGV RNA seroprevalence significantly decreased with increasing time since first drug injection, whereas the seroprevalences of both HCV RNA and anti-HCV antibody increased. Thus, a high proportion of HGV-infected persons may clear the virus and develop protective antibodies. The relatively high HGV RNA prevalence among non-drug-injecting homosexual and bisexual men indicates that sexual contact may be another important route of HGV transmission.
Upregulation of reactive oxygen and nitrogen intermediates in Plasmodium berghei infected mice after rescue therapy with chloroquine or artemether.
Plasmodium berghei ANKA infected C57B1/6 mice develop cerebral malaria at a parasitaemia of 15-25%. When parasitaemia reached 10%, P. berghei infected mice were treated with artemether, chloroquine or clindamycin in order to prevent the occurrence of cerebral malaria. Artemether and chloroquine were highly efficient. Functional tests revealed that zymosan stimulated spleen cells from untreated mice with cerebral malaria showed a slight decrease in their capacity to produce reactive oxygen intermediates (ROI) when compared with naive mice. After artemether or chloroquine treatment, the ROI production was significantly enhanced. The interferon-gamma induced production of reactive nitrogen intermediates (RNI) was slightly elevated in mice with cerebral malaria, but markedly elevated in artemether or chloroquine treated mice when compared with naive mice. Moreover, high levels of inducible nitric oxide synthase gene expression could be detected by in-situ hybridization in spleen sections of mice which had been treated with artemether or chloroquine. These findings suggest that increased production of ROI and RNI after chemotherapy may play a protective role for the host during malaria.
Methadone maintenance treatment and HIV risk-taking behaviour among injecting drug users in Berlin.
STUDY OBJECTIVE: To determine whether methadone maintenance treatment (MMT) is effective in reducing the levels of HIV risk-taking behaviour (borrowing and lending of injection equipment, irregular condom use) among injecting drug users (IDUs), and to identify independent predictors of the borrowing of used syringes. DESIGN: Cross sectional study of IDUs in MMT and not in MMT, using standardised interviews for collection of sociodemographic and behavioural data, and laboratory tests for detecting HIV antibodies. SETTING AND PARTICIPANTS: The 612 IDUs were recruited at different services for drug users such as treatment centres, walk in agencies, a hospital, and on the streets. MAIN RESULTS: Of all IDUs, 41% had borrowed and 34% had passed on used injection equipment in the previous six months. In univariate analysis, IDUs receiving MMT had injected less frequently and were significantly less likely to borrow and lend syringes. In logistic regression analysis, MMT was protective against the borrowing of syringes (adjusted odds ratio 0.36, 95% confidence interval 0.2, 0.8), but not against syringe lending nor against sexual risk behaviour (i.e., numbers of sex partners, lack of condom use). Important independent predictors of the borrowing of syringes were injecting drug use in prison, use of sedatives, and sex with another IDU in the previous six months. CONCLUSIONS: MMT may play a significant role in reducing the levels of borrowing of syringes among IDUs. However, additional prevention measures are needed which should specifically address sexual risk behaviour and target subgroups of IDUs with high levels of needle sharing, such as IDUs who have been in prison and and those who are sedative users.
Effects of Plasmodium vinckei hemozoin on the production of oxygen radicals and nitrogen oxides in murine macrophages.
When murine peritoneal macrophages were loaded in vitro with Plasmodium vinckei hemozoin and stimulated with opsonized zymosan for 90 min or with lipopolysaccharide and/or murine interferon-gamma for 24 hr, significant decreases in the production of oxygen radicals and nitrogen oxides, respectively, could be detected by comparison with macrophages without hemozoin. Moreover, nonradioactive in situ hybridization and immunohistologic analysis in liver sections of P. vinckei-infected mice with more than 60% parasitemia showed that liver cells were still expressing considerable levels of inducible nitric oxide synthase in the late phase of murine malaria, but most of the liver macrophages presenting accumulation of malaria pigment were negative in this analysis. These results further indicate that malaria pigment accumulation may be responsible for toxicity and impairment of macrophage functions during murine malaria.
Frontloading: a risk factor for HIV and hepatitis C virus infection among injecting drug users in Berlin.
OBJECTIVE: To determine whether frontloading (i.e., syringe-mediated drug-sharing) is a risk factor for HIV, hepatitis B virus (HBV) and hepatitis C virus (HCV) infection among injecting drug users (IDU). DESIGN: Cross-sectional study. Data on sociodemographic and behavioural characteristics were obtained by a standardized questionnaire. Serum samples were tested for seromarkers for HIV, HBV and HCV. SETTING AND PARTICIPANTS: IDU were recruited at 'low-threshold' storefront agencies (out-of-treatment sample), and at a centre for long-term drug use treatment (in-treatment sample). Individuals were included in the study if they had injected drugs within the previous 3 months. MAIN OUTCOME MEASURES: Serological evidence for HIV, HBV, HCV exposure. RESULTS: Of all IDU (n = 324), 84% had ever practised frontloading with non-sterile injecting equipment, and 46% had done so more than 100 times; 32% had front-loaded during the 6 months prior to the interview. The crude seroprevalence rates for HIV, HBV and HCV increased with the overall frequency of frontloading, and reached 22, 71 and 94%, respectively, among IDU who had frontloaded more than 100 times. After controlling for confounding effects by logistic regression, having practised frontloading more than 100 times was significantly associated with HIV infection [adjusted prevalence odds ratio (POR) 3.5; 95% confidence interval (CI), 1.4-9], and HCV infection (adjusted POR, 5.4; 95% CI, 2.3-12), but not with HBV infection. Another independent risk factor for all three virus infections was needle-sharing in prison. CONCLUSIONS: In communities where sterile injection equipment is readily available, and IDU have substantially reduced their overall levels of needle-sharing, the practice of frontloading appears to be a major risk factor for infections by blood-borne viruses among IDU. Prevention activities should specifically address this risk behaviour.
[Side effects of travel vaccinations. Data collection via telephone survey in Berlin].
The local and systemic side effects of some frequently administered travel vaccines were analysed in a prospective study on 3488 travelers using a standardised telephone interview procedure. The vaccines studied were yellow fever, diphtheria toxoid (d), tetanus diphtheria toxoid (Td), oral polio (OPV) and oral typhoid. Combined vaccinations studied were Td + OPV. Td + yellow fever. d + OPV and d + yellow fever. After single vaccination 30% of those inoculated reported slight local reactions. 3% had moderate local reactions and 18% complained about systemic side effects. After combined vaccinations 47% suffered from slight local reactions, 7% had moderate local reactions and 22% developed systemic side effects. Of all vaccines studied Td produced the highest frequency of local reactions. The combined vaccinations containing yellow fever vaccine were less well tolerated than the corresponding single vaccines. Systemic and local side effects were experienced more frequently by women, except in the case of diphtheria toxoid. Young travelers had more frequent and more severe side effects than older travelers after yellow fever vaccination, and after the combinations of Td + yellow fever. Td + OPV and d + yellow fever vaccinations. The side effects observed were mostly mild and none of the vaccinated travelers consulted a doctor for side effects. After travel vaccinations there are frequent, but well tolerated local and systemic side effects. Combined vaccinations are also well tolerated; their components determine the incidence of side effects.