Azide-Free Synthesis of N-Alkyliminophosphoranes from Phosphines and Hydroxylamine Derivatives

A broadly applicable and efficient method for the synthesis of N-alkyliminophosphoranes from phosphines that does not use potentially hazardous alkyl azides is reported. Under iron catalysis, a hydroxylamine-derived triflic acid salt oxidizes phosphines to a wide range of iminophosphorane triflic acid salts. Diphosphines afford phosphine-iminophosphoranes that can serve as ligands in transition metal complexes. The developed method can be employed in the synthesis of mixed diiminophosphoranes and in a traceless Staudinger ligation.

Severe underquantification of HIV-1 group O isolates by major commercial PCR-based assays

HIV-1 diversity poses major challenges to viral load assays because genetic polymorphisms can impede nucleic acid detection. In addition to the on-going viral diversification within the HIV-1 group M pandemic, HIV-1 genetic diversity is further increased by non-group M infections, such as HIV-1 groups O (HIV-1-O), N and P. We here conducted a systematic evaluation of commercially available PCR assays to detect HIV-1-O isolates. We collected 25 primary HIV-1-O isolates covering all genetic clusters within HIV-1-O. Subsequently, this panel of isolates was tested on eight commercially available quantitative and five qualitative HIV-1 PCR-based assays in serial dilutions. Sequence analyses were performed for severe cases of underquantification or lack of detection. We observed differences between the assays in quantification that depended on the HIV-1-O isolate's subgroup. All three tested HIV-1-O subgroup IV isolates were underquantified by the Roche CAP/CTM >800-fold compared to the Abbott RealTime assay. In contrast, the latter assay underquantified several subgroup I isolates >200-fold. Notably, the Xpert HIV-1 Viral Load test from Cepheid failed to detect two of the HIV-1-O isolates, whereas the Roche Cobas 8800 assay readily detected all isolates. Comparative sequence analyses identified polymorphisms in the HIV-1-O long-terminal repeat and integrase genes that likely underlie inadequate nucleic acid amplification. Potential viral load underquantification should be considered in therapeutic monitoring of HIV-1-O-infected patients. Pre-clinical assessments of HIV-1 diagnostic assays could be harmonized by establishing improved and internationally standardized panels of HIV-1 isolates that cover the dynamic diversity of circulating HIV-1 strains.

Correlation of Antibodies to LAV/HTLV III in Hemophiliacs with the Use of Virus-Inactivated Clotting Factors

The retrovirus LAV/HTLV III, highly likely to be responsible for the acquired immunodeficiency syndrome (AIDS) in some recipients of blood products, can be inactivated by chemical and/ or heat treatment, so the use of virus-inactivated factor VIII and factor IX preparations for treating hemophilia A and B has become important. We examined hemophilic children and found that those children treated since 1979 with virus-inactivated preparations did not develop antibodies against LAV/HTLV III. In contrast, 77% of patients treated with conventional factor VIII or factor IX preparations had antibodies against this virus.

Nebenwirkungen der Substitutionstherapie

Viren können über Blut und Blutprodukte übertragen werden. Blut kann nicht, Blutprodukte können bedingt inaktiviert werden und deswegen wird immer eine Restwahrscheinlichkeit der Übertragung von Infektionserregern verbleiben. Zu den heute in Europa transfusionsrelevanten Viren gehören das Hepatitis-B- und -C-Virus und die Immunschwäche-Viren. Diese drei Viren zeichnen sich durch hohe Mortalität und Chronizität der Erkrankung aus. Bedingt transfusionsrelevante Viren sind das Zytomegalievirus und das Parvovirus B19. Wegen der geringen Prävalenz nicht relevant ist das humane T-Leukämie-Virus in Mittel- und Nordeuropa, in Südeuropa kommen relevante Prävalenzen vor. Auf andere, nicht relevante Viren wird wegen ihrer geringen Bedeutung nicht getestet.

Comparison of peak oxygen uptake and exercise efficiency between upper-body poling and arm crank ergometry in trained paraplegic and able-bodied participants

Purpose

To compare peak oxygen uptake (VO_2peak) and exercise efficiency between upper-body poling (UBP) and arm crank ergometry (ACE) in able-bodied (AB) and paraplegic participants (PARA).

Methods

Seven PARA and eleven AB upper-body trained participants performed four 5-min submaximal stages, and an incremental test to exhaustion in UBP and ACE. VO_2peak was the highest 30-s average during the incremental test. Metabolic rate (joule/second = watt) at fixed power outputs of 40, 60, and 80 W was estimated using linear regression analysis on the original power-output-metabolic-rate data and used to compare exercise efficiency between exercise modes and groups.

Results

VO_2peak did not significantly differ between UBP and ACE (p = 0.101), although peak power output was 19% lower in UBP (p < 0.001). Metabolic rate at fixed power outputs was 24% higher in UBP compared to ACE (p < 0.001), i.e., exercise efficiency was lower in UBP. PARA had 24% lower VO_2peak compared to AB (p = 0.010), although there were no significant differences in peak power output between PARA and AB (p = 0.209).

Conclusions

In upper-body-trained PARA and AB participants, VO_2peak did not differ between UBP and ACE, indicating that these two test modes tax the cardiovascular system similarly when the upper body is restricted. As such, the 19% lower peak power output in UBP compared to ACE may be explained by the coinciding lower efficiency.

Electronic supplementary material

The online version of this article (10.1007/s00421-018-3912-1) contains supplementary material, which is available to authorized users.

[Prevention of nosocomial transmission of human immunodeficiency virus (HIV) from HIV-positive healthcare workers. Recommendations of the German Association for the Control of Viral Diseases (DVV) e.V. and the Society for Virology (GfV) e.V]

To the best of our knowledge, the German Association for the Control of Viral Diseases (DVV) e.V. and the Society for Virology (GfV) e.V. are the first in Europe to provide precise recommendations for the management of health care workers (HCWs) who are infected with human immunodeficiency virus (HIV). Requirements for HIV-infected HCWs need to be clearly defined. With a permanent viral burden of less than or equal to 50 copies/mL, HIV-positive HCWs are allowed to perform any surgery and any invasive procedure, as long as the infected HCW uses double-gloving, undergoes follow-up routinely by occupational medicine professionals, undergoes a quarterly examination of viral burden, and has a regular medical examination by a physician who has expertise in the management of HIV. Unrestricted professional activity is only possible with a strict compliance to take antiretroviral therapy and if the HIV-infected HCW strictly adheres to the recommended infection control procedures. Complete compliance with the recommendation almost certainly leads to no HIV transmission risk in patient care.

Mutations in the C-terminal region of the HIV-1 reverse transcriptase and their correlation with drug resistance associated mutations and antiviral treatment

OBJECTIVE

replication of HIV-1 after cell entry is essentially dependent on the reverse transcriptase (RT). Antiretroviral drugs impairing the function of the RT currently aim at the polymerase subunit. One reason for failure of antiretroviral treatment is the evolvement of resistance-associated mutations in the viral genome. For RT inhibitors, almost all identified mutations are located within the polymerase; therefore, general genotyping confines to investigate this subunit. Recently several studies have shown that substitutions within the RNase H and the connection domain increase antiviral drug-resistance in vitro, and some of them are present in patient isolates.

AIM

the aim of the present study was to investigate the prevalence of these substitutions and their association with mutations in the polymerase domain arising during antiretroviral treatment.

MATERIAL AND METHODS

we performed genotypic analyzes on seventy-four virus isolates derived from treated and untreated patients, followed at the HIV Centre of the Johann Wolfgang Goethe University Hospital (Frankfurt/Main, Germany). We subsequently ana?lysed the different substitutions in the c-terminal region to evaluate whether there were associations with each other, n-terminal substitutions or with antiretroviral treatment.

RESULTS

We identified several primer grip substitutions, but almost all of them were located in the connection domain. This is consistent with other in-vivo studies, in which especially the primer grip residues located in the RNase H were unvaried. Furthermore, we identified other substitutions in the connection domain and in the RNase H. Especially E399D seemed to be associated with an antiretroviral treatment and N-terminal resistance-delivering mutations.

CONCLUSION

some of the identified substitutions were associated with antiviral treatment and drug resistance-associated mutations. Due to the low prevalence of C-terminal mutations and as only a few of them could be associated with antiviral treatment and N-terminal resistance-delivering mutations, we would not recommend routinely testing of the C-terminal RT region.

Tissue donation and virus safety: more nucleic acid amplification testing is needed

In tissue and organ transplantation, it is of great importance to avoid the transmission of blood-borne viruses to the recipient. While serologic testing for anti-human immunodeficiency virus (HIV)-1 and -2, anti-hepatitis C virus (HCV), hepatitis B surface antigen (HBsAg), anti-hepatitis B core antigen (HBc), and Treponema pallidum infection is mandatory, there is until now in most countries no explicit demand for nucleic acid amplification testing (NAT) to detect HIV, hepatitis B virus (HBV), and HCV infection. After a review of reports in the literature on viral transmission events, tissue-specific issues, and manufacturing and inactivation procedures, we evaluated the significance of HIV, HCV, and HBV detection using NAT  in  donors of various types of tissues and compared our results with the experiences of blood banking organizations. There is a significant risk of HIV, HCV, and HBV transmission by musculoskeletal tissues because of their high blood content and the high donor-recipient ratio. If no effective virus inactivation procedure for musculoskeletal tissue is applied, donors should be screened using NAT  for  HIV, HCV, and HBV. Serologically screened cardiovascular tissue carries a very low risk of HIV, HCV, or HBV transmission. Nevertheless, because effective virus inactivation is impossible (retention of tissue morphology) and the donor-recipient ratio may be as high as 1:10, we concluded that NAT  should be performed for HIV, HCV, and HBV as an additional safety measure. Although cornea allografts carry the lowest risk of transmitting HIV, HCV, and HBV  owing to corneal physiology, morphology, and the epidemiology of corneal diseases, NAT  for  HCV should still be performed. If the NAT  screening of a donor for HIV, HCV, and HBV is negative, quarantine storage of the donor tissue seems dispensable. In view of numerous synergistic effects with transfusion medicine, it would be advantageous for tissue banks to cooperate with blood bank laboratories in performing virological tests.

[Global warming: trailblazer for tropical infections in Germany?]

Since 1850, the CO (2) content of the atmosphere has increased from 280 to 360 ppm, and the average surface temperature has risen from 14.6 to 15.3 C . A further increase between 1.8 and 4.0 C is expected for the 21st century. Temperate and cold climate zones are affected predominantly, but tropical regions are not spared. At the same time, the world wide climate effects of the "El Niño Southern Oscillation" are amplified. Global warming enhances the growth of tropical pathogens (malarial plasmodia, leishmania, yellow fever virus, dengue virus, West Nile virus, Vibrio cholerae) and vectors (anopheles, aedes, culex, and phlebotomus mosquitos; hard ticks). Global warming may lead to the emergence of diseases which at present are not endemic in Germany, like West Nile fever, Dengue fever, or Leishmaniases, and to enhanced transmission of borreliosis and tick-borne encephalitis. Malaria and cholera, in contrast, are influenced more strongly by socioeconomic factors. Improved surveillance and intensified research on the relationship between climate change and infectious diseases is needed.

No influence of atopic diseases on antibody titres following tetanus, diphtheria and hepatitis B immunisation among adults

Several studies have reported associations between reduced humoral immune response to vaccine antigens and diseases with modified reactions of the immune system. We have investigated the influence of atopic diseases on specific IgG levels to tetanus, diphtheria and hepatitis B (HB), following immunisation, in a general adult population. From the Study of Health in Pomerania, a total number of 3,920 subjects aged 20 to 79 years were included in the analyses. Information on immunisation history, as well as behavioural and socio-demographic characteristics were collected. Anti-tetanus IgG, anti-diphtheria IgG and anti-HBs IgG were measured by indirect enzyme-linked immunosorbent assay (ELISA). Odds ratios and 95% confidence intervals were calculated using logistic regression. Atopic diseases were reported by 14% of participants. Proportions of 67%, 34% and 10% had been vaccinated against tetanus, diphtheria and hepatitis B within the past ten years, respectively. Multi-variable analyses revealed no associations between the presence of atopic diseases and all of the three vaccine-specific antibody titres. We conclude that there is no reduced immune response related to antibody production following immunisations against tetanus, diphtheria and hepatitis B in adults with atopic diseases.

[Bilateral retinal vasculitis with arterial aneurysms]

The authors reported unusual and rare condition of bilateral retinal vasculitis primarily affecting the central retinal artery at the nerve head and its 4 main branches. The most striking feature was the presence of the diffuse vitreous cells, occlusion of branch retinal artery, segmental periarterial infiltration, arterial sheating, retinal arterial aneurysms, disc swelling, peripheral retinal non perfusion and their complications. During 13 year's observation and treatment one eye went blind 3 years after initial examination. Second eye started the same clinical course two years after beginning of the disease. To avoid similar devastating course of the disease we started systemic steroids and immunosuppressive therapy, followed by photocoagulation of nonperfused peripheral retina and vitreoretinal surgery. We achieved stabilization of the disease with decreased visual functions. Comprehensive systemic work-up was unrevealing, no clear etiology was identified and diagnosis of idiopathic retinal vasculitis was made.

Enterovirus RNA sequences in sera of schoolchildren in the general population and their association with type 1-diabetes-associated autoantibodies

Type 1 diabetes (T1D) is an autoimmune disease linked with genetic factors as well as with environmental triggers, such as virus infections, but the aetiology is still unclear. The authors analysed serum from autoantibody-positive (n=50) and autoantibody-negative (n=50) schoolchildren as well as children newly diagnosed with T1D (n=47; time from diagnosis, median 5 days, interquartile range 1-12 days) for the presence and frequency of enterovirus (EV) and adenovirus sequences. The autoantibody-positive and -negative groups were part of the Karlsburg Type 1 Diabetes Risk Study of a Normal Schoolchild Population, which represents a general population without T1D first-degree relatives. There was no significant seasonality of sampling in any of the three groups investigated. EV RNA sequences were detected in 10 of 50 (20%) autoantibody-positive children and in 17 of 47 (36%) children newly diagnosed with T1D, but only in two of 50 (4%) of the age- and sex-matched controls (P<0.05, P<0.001). Characterization of the EV amplicons by direct sequencing revealed high homology with coxsackievirus B group. For adenovirus we found no data to support an association with T1D. The data support the hypothesis that different enteroviruses may be aetiologically important as a trigger and/or accelerating factor in the process of T1D development.

Chlamydophila pneumoniae respiratory tract infection aggravates therapy refractory bronchitis or pneumonia in childhood

BACKGROUND

Chlamydophila pneumoniae was frequently found in bronchial secretions of children with therapy-refractory bronchitis or pneumonia. It was studied, how the agent modifies the course of disease and what findings are associated with the infection.

PATIENTS AND METHODS

Bronchial secretions obtained at bronchoscopy of 428 children were studied for C. pneumoniae infection using polymerase chain reaction with enzyme immunoassay detection. Children tested negative and positive were compared for their clinical findings.

RESULTS

C. pneumoniae was found in 143 children (33 %). A C. pneumoniae infection has been found to be associated with a purulent bronchial inflammation (90/143 vs. 144/285, p = 0.02), a Streptococcus pneumoniae co-infection (13/143 vs. 6/285, p = 0.002) and a restrictive disturbance (11/51 vs. 8/93, p = 0.04). Purulent inflammation (Odds ratio 7.9; 95 % confidence interval [CI] 1.6-39.3), 2 co-infections (Odds ratio 14.3; 95 % CI 1.4-144.4) and co-infection with M. pneumoniae (4/4 versus 9/26, p = 0.03; Mantel Haentzel 3.0; 95 % CI 1.1-8.0) were identified as factors more often associated with a restrictive disturbance in children with bronchial C. pneumoniae infection. An adequate antibiotic therapy improved pulmonary function. No association was found for wheezing, eosinophil inflammation of the nasal mucosa, alpha-1 antitrypsin or immunoglobulin deficiency in serum, level of secretory IgA in bronchial mucus, pathological lung scintigram, gastro-esophageal reflux disease, sweat test and other co-infections.

CONCLUSIONS

In children with therapy-refractory bronchitis or pneumonia bronchial C. pneumoniae infection was associated with a more severe disease in case of several, mostly bacterial co-infections. Adequate antibiotic therapy for C. pneumoniae infection has been demonstrated to improve pulmonary function.

Mikrobiologische Diagnostik ausgewählter bakterieller Hautinfektionen

Using as examples either common or important but less frequent bacterial skin diseases, detailed practice-oriented information is provided on microbiologic diagnostic procedures. Despite the availability of many advanced techniques, often the simplest measures can provide the correct diagnosis and help guide therapy. The practicing physician must also know what is required for more advanced diagnostic procedures; if they are used improperly, unnecessary costs accumulate. Conversely, the decision process and technical methods must be understandable for those without special background in microbiology. The value of all methods is discussed from the perspective of dermatology with emphasis on appropriate sampling and handling of specimens.

[SIV as a source of HIV. On the origin of human immunodeficiency viruses from non-human primates]

It is assumed that HIV, the human immunodeficiency virus, started its spread after the Second World War. Molecular analysis of the genome of various HIV-1 types has shown that this virus can be divided into the groups M, N, and O and that these genome sequences fit perfectly to the genomes found in SIV of chimpanzees (SIVcpz) living in the area of West and Central Africa. SIVcpz is nonpathogenic for chimpanzees indicating that the virus and host have adapted for a long period. HIV-2 genome sequences converge with SIV sequences of sooty mangabey monkeys from West Africa (SIVsm), covering the subtypes A to G from HIV-2. SIVsm is nonpathogenic for mangabey monkeys. All available data indicate that HIV-1 and HIV-2 have been introduced into humans at least several times. Since SIVcpz and SIVs from other monkeys are recombinant viruses, it cannot be excluded that a new recombinant SIV might again enter the human population and initiate a new epidemic.

Are enterovirus infections a co-factor in sudden hearing loss?

Since viral infections are believed to be one of the causes of sudden hearing loss we have used serological assays for herpes simplex virus (HSV), varicella zoster virus (VZV), and enterovirus as well as polymerase chain reaction for enterovirus to test 55 sudden hearing loss patients for viral infections. Serological screening of these patients for HSV and VZV failed to reveal significant differences between the patient group and the controls. In contrast, enterovirus sequences were detected by RT-PCR in 40% of the patient group, but in none of the controls, suggesting that enterovirus infections may be associated with sudden hearing loss.

Molecular and clinical characteristics of respiratory syncytial virus infections in hospitalized children

The objective of this study was to determine the importance of respiratory syncytial virus (RSV) for hospitalization in the north east of Germany and to obtain molecular epidemiological data of the circulating strains. Using a rapid and sensitive reverse transcriptase-PCR, it was found that a quarter of pediatric respiratory disease admissions were due to RSV. Infections caused by RSV in hospitalized patients were determined over the whole year. Both RSV groups A and B were identified with a predominance of RSV A (86%) over the entire period. The analysis of the deduced amino acid sequences by direct sequencing showed that very similar RSV strains are circulating in the community.

Chlamydia pneumoniae Carriage and Infection in Hospitalized Children with Respiratory Tract Diseases

BACKGROUND

The importance of Chlamydia pneumoniae respiratory tract infection in childhood is under discussion.

PATIENTS AND METHODS

798 hospitalized children with respiratory tract diseases were prospectively studied during a 2-year period by polymerase chain reaction and enzyme immunoassay (PCR-EIA) detection from throat swabs. Paired serum samples were used to screen for Chlamydia antibodies.

RESULTS

C. pneumoniae was detected by PCR-EIA in 74 children. Prevalence was 11% in lower and 4% in upper respiratory tract disease (p = 0.049) without age dependency. From November to February prevalence was elevated (42/277 vs. 32/521; p < 0.001). Using serology, prevalence of acute Chlamydia infection increased with age (p < 0.001) and the number of coinfections (p < 0.001), without seasonal variation.

CONCLUSION

Characteristics of C. pneumoniae carriage in the respiratory tract in childhood differ from those in systemic infection.

Real-time PCR to improve the diagnosis of respiratory syncytial virus infection

Respiratory syncytial virus (RSV) is one of the most important virus respiratory pathogens in infants and young children. A rapid and sensitive diagnosis is essential to focus any outbreak due to this virus. A real-time RT-PCR method was designed using a primer/probe pair from the F gene. Simultaneously with nested RT-PCR and antigen ELISA, 71 consecutive specimens from hospitalized children with clinical symptoms of acute respiratory distress were evaluated to confirm the incidence of RSV infection. RSV was detected in 25 (35.2 %) specimens by real-time RT-PCR and in 19 (26.7 %) by nested RT-PCR. The assay was specific for RSV. The procedure offers a rapid and sensitive alternative to conventional RT-PCR. Closed-tube detection eliminates the risk of contamination.

Effect of antiretroviral triple combinations including the protease inhibitor nelfinavir in heavily pretreated children with HIV-1 infection

BACKGROUND

In this retrospective study the effect of antiretroviral triple therapy including the protease-inhibitor nelfinavir (NFV) on CD4-cells and viral load (VL) in heavily pretreated HIV-infected children was evaluated.

PATIENTS AND METHODS

20 children (<18 years) were included. Median duration of antiretroviral pretreatment was 27 months (range, 7 65), median initial VL was 4.7 log subset 10 (3.2 6.1) and median relative CD4-cells was 17.5% (3 33). Patients were put on combinations with NFV because of treatment failure (increasing VL), intolerance to prior therapy with PIs or adherence problems with prior indinavir. Viral load (RT-PCR, detection limit 50 copies/ml) and CD4-cells were measured every 4-8 weeks.

RESULTS

Median viral load decreased 1.2 log(10) (-1.3 2.5), 0.9 log(10) (-0.8 - 2.5) and 0.4 log(10) (-0.5 - 3.0) after 12, 24 and 36 weeks. The VL of 2 patients was below the detection limit (50 copies/ml) after 24 weeks. The relative CD4-cell count increased from a median of 17.5% to 22%, 23% and 25% after 12, 24 and 36 weeks, respectively. Side effects of NFV were usually mild. WHO grade 1 or 2 diarrhea occurred in 70% and moderate elevations of triglycerides in 40% of the patients. At 48 weeks 18/20 patients had to be switched to other combinations due to virological failure.

CONCLUSIONS

In children with intensive prior antiretroviral therapy combination therapy including NFV lead to a modest short-term reduction of the VL and increase in CD4-cells. However, the long-term antiretroviral effect was poor.

[Hepatitis C in Germany. More than 5000 new infections annually]

The number of people infected with HCV in Germany is estimated to be 300,000. New infections total 5100 every year, with drug consumption playing a major transmission role. Since the introduction of routine tests, the risk of contracting HCV infection from donated blood has now decreased to less than 1 in 1 million. For diagnostic purposes, antibody screening assays, confirmation assays to exclude false positive results (immunoblot), core antigen assay and nucleic acid testing are employed. An effective vaccine against HCV infection is still not available, so that prevention of transmission must continue to be the main aim of prophylaxis. In this connection, every practicing physician is expected to know his infection status for HCV, HIV and HBV.

Naturally occurring sequence polymorphisms within HIV type 1 group O protease

Mutations within the protease gene associated with reduced susceptibility to protease inhibitors have been well documented for HIV-1 group M subtype B strains. In contrast, limited genotypic and phenotypic information is available for the genetically diverse HIV-1 group O strains. Preexisting resistance-associated polymorphisms have the potential to contribute to a poor virological response to antiviral drug treatment in group O-infected patients. In the present study, the protease genes of 28 protease inhibitor-naive HIV-1 group O-infected patients were analyzed to identify any naturally occurring amino acid polymorphisms associated with drug resistance. Comparison of the consensus group O protease sequence with subtype B of group M indicated that both groups have almost identical sequences in the protease active site, the flap and the substrate-binding site. Analysis of the 28 individual protease sequences revealed polymorphisms at 34% of the positions within the protease gene, but no primary mutations associated with protease inhibitor resistance. In contrast, each of the strains harbored multiple secondary or accessory mutations associated with resistance to protease inhibitors in group M viruses. Residues 10I, 15V, 36I, 41K, 62V, 63T/A/K/I, 64V, 71V, and 93L were identified in most strains. The presence of multiple natural sequence polymorphisms associated with drug resistance in the protease gene of group O viruses may contribute to a more rapid emergence of drug resistance phenotype and treatment failure in group O-infected patients.

Diagnostics and treatment of HIV-discordant couples who wish to have children

Over the last years the reality surrounding HIV-infection has undergone a considerable change with regard to the life expectancy of patients, and the plans they can make for their lives. Because the majority of the HIV positive population is of reproductive age, one of these plans might be to have children, often as an expression of a fulfilled partnership. The need for medical support to realize this wish, however, is often confronted with ethical, medical or forensic restraints. For this reason, interdisciplinary recommendations have now been developed--for the first time on a global basis--which aim to provide guidelines for practitioners in this complicated area.

Comparison of the efficacy of virus inactivation methods in allogeneic avital bone tissue transplants

Several procedures for inactivating viruses are used presently in the context of bone tissue transplants. Common methods used are gamma irradiation (25 kGy), treatment with moist heat (82.5 degrees C/15 min., lobator-sd2-system) as well as chemical sterilisation using peracetic acid-ethanol treatment (PES, 2% peracetic acid, 96% ethanol, Aqua [2:1:1], 200 mbar, agitation, 4 hours). Based on national and international guidelines, we tested the antivirucidal effectiveness of these methods in human bone transplants. Three enveloped viruses: human immunodeficiency virus type 2 (HIV-2), pseudorabies virus (PRV), bovine virus diarrhoea virus (BVDV), and three non-enveloped viruses were used: hepatitis A virus (HAV), poliovirus (PV-1), porcine/bovine parvovirus (PPV, BPV). Defatted spongiosa cuboids served as model in chemical treatment experiments, while cortical diaphyses were used in gamma irradiation experiments, and the effects of thermal treatment were tested in prepared femoral heads. The log(10) reduction was measured by cytopathogenic effects after virus titration (TCID(50)/mL). A dose of at least 33.9 kGy (bone model) at -30 +/- 5 degrees C was necessary to achieve a sufficient reduction (4 log(10) steps) of BPV, the most resistant one of all viruses investigated. Thermal treatment as well as PES treatment led to a reduction of virus titres by more than 4 log(10). Only HAV showed a reduction below 4 log(10) (2.87) with PES. After validation of the defatting step included for HAV-infected cells, a HAV-reduction of over 7 log(10) was found. All three sterilisation methods tested are recommended for bone transplant sterilisation, but only provided that additional safety measures (anamnestic informations, infectious serology, PCR in case of multiorgan donors) are taken.

Inhibition of adenovirus DNA polymerase by modified nucleoside triphosphate analogs correlate with their antiviral effects on cellular level

Adenovirus (Ad) infection results in significant morbidity and mortality in both immunocompetent and immunosuppressed hosts. There is currently no licensed chemotherapy effective in dealing with this virus infection. In this study the anti-adenoviral activity of a group of modified nucleoside analogs was investigated. The most efficient 3-fluorosubstituted nucleoside triphosphate inhibitors of Ad DNA polymerase were 3'-fluorothymidine triphosphate (IC50 0.63 microM), 2',3'-dideoxy-3'-fluoroguanosine triphosphate (IC50 0.71 microM) and 2',3'-dideoxy-3'-fluorouridine triphosphate (IC50 2.96 microM). The most efficient 2',3'-dideoxynucleoside triphosphates were 2',3'-dideoxycytidine triphosphate (ddCTP; IC50 1.0 microM), 2',3'-dideoxyadenosine triphosphate (IC50 1.6 microM) and 2',3'-dideoxythymidine triphosphate (IC50 1.82 microM). Kinetic studies indicate competitive inhibition of adenovirus DNA polymerase by ddCTP. These data confirm results previously obtained at the cellular level using a focus reduction assay involving Ad2-infected FL cells. Whereas the D-enantiomers 3'-fluorothymidine and 2',3'-dideoxycytidine are potent inhibitors of adenoviral replication, the corresponding L-enantiomers exhibited no inhibitory activity.

Shortening of the diagnostic window with a new combined HIV p24 antigen and anti-HIV-1/2/O screening test

Because antibodies to the human immunodeficiency virus (HIV) are absent in the very early phase of HIV infection, there remains a slight residual risk for HIV transmission by blood donations by viremic but antibody negative donations. To shorten the diagnostic window between infection and the detection of antibodies, Enzygnost HIV Integral (Dade Behring, Germany) was developed. With this new test, HIV p24 antigen and HIV antibodies can be detected simultaneously in a single test. In a multicenter study the new screening assay has been compared with various tests that detect only HIV antibodies or HIV p24 antigen and with assays which permit a simultaneous detection of HIV antigen and HIV antibodies. The new assay showed 100% sensitivity for the detection of antibodies to HIV-1, groups M (n=1102) and O (n=55), and HIV-2 (n=289). In 23 out of 52 seroconversion panels, seroconversion was detected 2-18 days earlier with the new combined antigen/antibody test compared to single antibody tests. All samples from a viral load panel (n=451), all samples containing p24 antigen (n=302), and all but one of the cell culture supernatants (n=38) infected with various HIV-1 subtypes or HIV-2 were identified reliably by the new test. The specificity of the assay for 4002 unselected blood donors was 99.78% initially and 99.80% after retesting. Potentially interfering factors had no systematic influence on specificity. By testing for p24 antigen, which is present prior to the onset of antibody production in some cases of recent HIV infection, the new assay reduces the diagnostic window as compared to third generation screening assays, thus permitting an earlier diagnosis of HIV infection.

Detection of HIV-1 infection in dried blood spots from a 12-year-old ABO bedside test card

BACKGROUND AND OBJECTIVES

We tested dried blood from an ABO bedside test card which had been stored at room temperature for 12 years, to prove that a patient with HIV-1 infection had been infected by blood transfusion.

MATERIALS AND METHODS

Immunoblots for HIV-1 antibodies and threefold PCRs with half-nested primers for the HIV-1 integrase gene were done with eluates from the dried blood spots.

RESULTS

HIV-1 antibodies and HIV-1 DNA could be detected in the sample from one unit of blood, but not from the two other units or from the recipient before transfusion.

CONCLUSION

Further studies should be done on the validity of stored dried blood as an alternative to the storage of frozen donor serum for several years for 'look-back' studies.

Hodgkin's disease related Kaposi's sarcoma in a non HIV infected male patient: a case report and review of the literature on a rare condition

A higher incidence of coexisting lymphoproliferative disease and Kaposi's sarcoma (KS) has been reported. However, the association of Hodgkin's disease (HD) and KS is a rare condition, and only 41 cases have been found upon a literature review of the last 33 years. In this study the case of a 70 year-old male patient with consecutive appearance of Hodgkin's disease (HD) and Kaposi's sarcoma (KS) without evidence of HIV infection or other immunodeficiency is presented. The data suggest, that the association of KS with HD may be due to common pathogenic mechanisms, rather than a direct causal relationship, except the requirement of an impaired immune system for the development of KS. Recently development of HD and KS has been associated with EBV and HHV-8, respectively. Neither immunosuppression, nor EBV or HHV-8 infection alone result in development of HD or KS. There is no clear time relationship between the development of KS and HD when the two occurred together in the same patient. That finding, coupled with the rarity of the association, suggest, that the association is more likely coincidental.

Comparison of ritonavir plus saquinavir- and nelfinavir plus saquinavir-containing regimens as salvage therapy in children with human immunodeficiency type 1 infection

BACKGROUND

In this retrospective study we compared the antiretroviral effect of regimens consisting of simultaneous administration of two protease inhibitors (PI) with at least one nucleoside reverse transcriptase inhibitor on plasma viral load (VL) and CD4 cell count in HIV-infected children intensively pretreated with nucleoside reverse transcriptase inhibitors and PIs.

METHODS

Eleven HIV-infected children were changed to antiretroviral combination regimens including two PIs and followed for a median time of 24 weeks. Group A comprised six patients who were given ritonavir + saquinavir (SQV) and Group B consists of five patients who were changed to nelfinavir + SQV. Patients were treated with these combinations with 2 PIs because of treatment failure (increasing viral load) of prior PI therapy or clinical signs of disease progression.

OUTCOME MEASURES

Serial determinations of plasma viral load (Amplicor, Roche) and CD4 cells were performed every 4 to 8 weeks. The detection limit of the Amplicor-reverse transcriptase-PCR assay was 50 copies/ml (1.7 log10).

RESULTS

In Group A the median VL reduction was 1.1 log10 after 3 months and 1.4 log10 after 6 months. In Group B median VL decreased 0.1 and 0.2 log10 after 3 and 6 months. In both groups during the study period none of the patients reached undetectable VL. The relative changes of CD4 cells above baseline in Group A showed a median increase of 7% after 3 months and 23% after 6 months. In Group B after 3 months CD4 cells did not increase, and after 6 months the median relative increase was only 7%. Both combination therapies were well tolerated, not necessitating any drug interruption during study period.

CONCLUSIONS

In children with intensive prior antiretroviral treatment, a salvage therapy including two PIs demonstrated antiretroviral efficacy in some patients. In this study the reduction of the VL as well as the increase of CD4 cells was more pronounced with ritonavir + SQV than with nelfinavir + SQV. With both combinations complete suppression of HIV replication was not achieved. Therefore the long term effect of these combinations may be limited by the emergence of resistant HIV strains.

Coreceptor requirements of primary HIV type 1 group O isolates from Cameroon

HIV-1 group O has its epicenter in Cameroon and neighboring countries and is responsible for 3 to 5% of all HIV infections in this region. It is believed that HIV-1 group O was introduced into the human population by a separate cross-species transmission, occurring independently of the HIV-1 (group M and group N) and HIV-2 transmissions. We have studied the coreceptor requirements of 12 primary HIV-1 O-type isolates from individuals with different clinical symptoms. Only 2 of these 12 viruses showed a syncytium-inducing phenotype after infection of primary peripheral blood mononuclear cells (PBMCs) and were infectious for the T cell line C8166. These isolates used CXCR4 as a coreceptor for entry, whereas the remaining isolates used only CCR5 efficiently. One isolate was able to use BOB and CCR8 as coreceptors in addition to CXCR4. All group O isolates tested were efficiently inhibited by SDF-1 or RANTES, the natural ligands of CXCR4 and CCR5, respectively. These results indicate that CXCR4 and CCR5 are the principal coreceptors for HIV-1 O-type viruses. Most of the HIV-1 group O isolates studied were derived from patients at later stages of the disease. Although HIV-1 group O and group M infections do not differ in their pathogenesis, the studied isolates did not evolve to use a broad range of coreceptors as described for HIV-1 group M and HIV-2.