SARS-CoV-2-specific cellular and humoral immunity after bivalent BA.4/5 COVID-19-vaccination in previously infected and non-infected individuals

Knowledge is limited as to how prior SARS-CoV-2 infection influences cellular and humoral immunity after booster-vaccination with bivalent BA.4/5-adapted mRNA-vaccines, and whether vaccine-induced immunity may indicate subsequent infection. In this observational study, individuals with prior infection (n = 64) showed higher vaccine-induced anti-spike IgG-antibodies and neutralizing titers, but the relative increase was significantly higher in non-infected individuals (n = 63). In general, both groups showed higher neutralizing activity towards the parental strain than towards Omicron-subvariants BA.1, BA.2 and BA.5. In contrast, CD4 or CD8 T cell levels towards spike from the parental strain and the Omicron-subvariants, and cytokine expression profiles were similar irrespective of prior infection. Breakthrough infections occurred more frequently among previously non-infected individuals, who had significantly lower vaccine-induced spike-specific neutralizing activity and CD4 T cell levels. In summary, we show that immunogenicity after BA.4/5-bivalent vaccination differs between individuals with and without prior infection. Moreover, our results may help to improve prediction of breakthrough infections.

[Cell-based influenza vaccines: an effective vaccine option for under 60-year-olds]

The population < 60 years of age is also affected by a significant disease burden from seasonal influenza. It carries a high economic burden, mainly driven by influenza-associated productivity losses in the working population. Conventional egg-based influenza vaccines may experience reduced effectiveness due to antigen adaptation in eggs. In contrast, cell-based influenza vaccines are less likely to be affected by antigenic adaptations to the host system and showed better effectiveness in individuals 4-64 years old over several seasons compared to conventional egg-based influenza vaccines under real-world conditions. Preferential use of cell-based influenza vaccines, as opposed to conventional egg-based vaccines, could reduce the burden of influenza-related symptoms on individuals and alleviate the economic impact on the German population < 60 years of age.

Microbiological Surveillance of Heater-Cooler Units Used in Cardiothoracic Surgery for Detection of Mycobacterium chimaera

Mycobacterium chimaera is a nontuberculous mycobacterium that was identified as causative agent in a global outbreak of severe infections following open-chest cardiothoracic surgery. Heater-cooler units (HCUs), which were contaminated during the manufacturing process, were elucidated as the origin of this outbreak. Regular surveillance of water-containing HCUs used for cardiac surgery was recommended as one preventive measure. We present data on the occurrence of M. chimaera and other mycobacterial pathogens in different HCUs from one surgical center in Germany over a 42-month period. Water samples and swabs from seven different HCUs were taken between 2015 and 2018, and mycobacteria were detected in 50.6% (78/154) of water samples and 21.1% (4/19) of swabs. M. chimaera accounted for the majority of detected pathogens (77/83 isolates in water samples), but other species such as Mycobacterium gordonae were also found. Despite strict adherence to an intensified, regular disinfection procedure, the majority of HCUs remained positive for mycobacteria until the end of the study. In conclusion, additional measures are needed to reduce the risk of intraoperative transmission of M. chimaera, and our observations underscore the inherent infections risks associated with water-containing medical devices.

Real world evidence for public health decision-making on vaccination policies: perspectives from an expert roundtable

INTRODUCTION

Influenza causes significant morbidity and mortality, but influenza vaccine uptake remains below most countries' targets. Vaccine policy recommendations vary, as do procedures for reviewing and appraising the evidence.

AREAS COVERED

During a series of roundtable discussions, we reviewed procedures and methodologies used by health ministries in four European countries to inform vaccine recommendations. We review the type of evidence currently recommended by each health ministry and the range of approaches toward considering randomized controlled trials (RCTs) and real-world evidence (RWE) studies when setting influenza vaccine recommendations.

EXPERT OPINION

Influenza vaccine recommendations should be based on data from both RCTs and RWE studies of efficacy, effectiveness, and safety. Such data should be considered alongside health-economic, cost-effectiveness, and budgetary factors. Although RCT data are more robust and less prone to bias, well-designed RWE studies permit timely evaluation of vaccine benefits, effectiveness comparisons over multiple seasons in large populations, and detection of rare adverse events, under real-world conditions. Given the variability of vaccine effectiveness due to influenza virus mutations and increasing diversification of influenza vaccines, we argue that consideration of both RWE and RCT evidence is the best approach to more nuanced and timely updates of influenza vaccine recommendations.

Alterations in pathogen-specific cellular and humoral immunity associated with acute peripheral facial palsy of infectious origin

BACKGROUND

Peripheral facial palsy (PFP) is a common neurologic symptom which can be triggered by pathogens, autoimmunity, trauma, tumors, cholesteatoma or further local conditions disturbing the peripheral section of the nerve. In general, its cause is often difficult to identify, remaining unknown in over two thirds of cases. As we have previously shown that the quantity and quality of pathogen-specific T cells change during active infections, we hypothesized that such changes may also help to identify the causative pathogen in PFPs of unknown origin.

METHODS

In this observational study, pathogen-specific T cells were quantified in blood samples of 55 patients with PFP and 23 healthy controls after stimulation with antigens from varicella-zoster virus (VZV), herpes-simplex viruses (HSV) or borrelia. T cells were further characterized by expression of the inhibitory surface molecule CTLA-4, as well as markers for differentiation (CD27) and proliferation (Ki67). Pathogen-specific antibody responses were analyzed using ELISA. Results were compared with conventional diagnostics.

RESULTS

Patients with PFP were more often HSV-seropositive than controls (p = 0.0003), whereas VZV- and borrelia-specific antibodies did not differ between groups. Although the quantity and general phenotypical characteristics of antigen-specific T cells did not differ either, expression of CTLA-4 and Ki67 was highly increased in VZV-specific T cells of 9 PFP patients, of which 5 showed typical signs of cutaneous zoster. In the remaining 4 patients, a causal relationship with VZV was possible but remained unclear by clinical standard diagnostics. A similar CTLA-4- and Ki67-expression profile of borrelia-specific T cells was also found in a patient with acute neuroborreliosis.

DISCUSSION

In conclusion, the high prevalence of HSV-seropositivity among PFP-patients may indicate an underestimation of HSV-involvement in PFP, even though HSV-specific T cell characteristics seem insufficient to identify HSV as a causative agent. In contrast, striking alterations in VZV- and borrelia-specific T cell phenotype and function may allow identification of VZV- and borrelia-triggered PFPs. If confirmed in larger studies, antigen-specific immune-phenotyping may have the potential to improve specificity of the clinical diagnosis.

Attitudes of primary care physicians towards antimicrobial stewardship and the impact of a multi-part training course - a pilot study

Background

A plethora of antimicrobial stewardship (AMS) programs has been initiated during the past years, focusing on hospital settings. Primary-care physicians have seldom been addressed, although the majority of antibiotic prescriptions are issued for outpatients. We sought to investigate attitudes of primary-care physicians and the impact of a customized training course.

Methods

Primary-care physicians in southwest Germany were invited to a multi-part training course on AMS in the primary-care setting. Participants were asked to answer a questionnaire about their attitude and factors that hinder them from implementing AMS or enable them to perform AMS. In addition, a knowledge assessment exam at the beginning and end of the training was conducted on selected infectious diseases/syndromes.

Results

In total, 36 primary-care physicians participated in the training course. The predominant age group was 51-60 years old (36%; 13/36). The majority, 23/35 (66%), indicated never having had AMS training, while 22/35 (63%) acknowledged partly implementing AMS activities in their daily routine. The primary barrier was lack of expertise, while the main motives were reducing antimicrobial resistance and optimizing patient care. The provision of guidelines was regarded as more important than feedback on their prescription behavior. Exam performance improved from the initial to the final exam on all topics.

Conclusion

Customized AMS training courses are a feasible and potentially complimentary tool to address antibiotic misuse in the primary-care setting.

Differences in SARS-CoV-2 specific humoral and cellular immune responses after contralateral and ipsilateral COVID-19 vaccination

BACKGROUND

Individual doses of dual-dose vaccine-regimens are sequentially administered into the deltoid muscle, but little attention has so far been paid to the immunological effects of choosing the ipsilateral or the contralateral side for the second dose.

METHODS

In an observational study, 303 previously naive individuals were recruited, who received the second dose of the COVID-19 vaccine BNT162b2 on either the ipsilateral (n = 147) or the contralateral side (n = 156). Spike-specific IgG, IgG-avidity, and neutralizing antibodies were quantified using ELISA and a surrogate assay 2 weeks after dose 2. A subgroup of 143 individuals (64 ipsilateral, 79 contralateral) was analysed for spike-specific CD4 and CD8 T-cells using flow-cytometry.

FINDINGS

Median spike-specific IgG-levels did not differ after ipsilateral (4590 (IQR 3438) BAU/ml) or contralateral vaccination (4002 (IQR 3524) BAU/ml, p = 0.106). IgG-avidity was also similar (p = 0.056). However, neutralizing activity was significantly lower after contralateral vaccination (p = 0.024). Likewise, median spike-specific CD8 T-cell levels were significantly lower (p = 0.004). Consequently, the percentage of individuals with detectable CD8 T-cells was significantly lower after contralateral than after ipsilateral vaccination (43.0% versus 67.2%, p = 0.004). Spike specific CD4 T-cell levels were similar in both groups, but showed significantly higher CTLA-4 expression after contralateral vaccination (p = 0.011). These effects were vaccine-specific, as polyclonally stimulated T-cell levels did not differ.

INTERPRETATION

Both ipsilateral and contralateral vaccination induce a strong immune response, but secondary boosting is more pronounced when choosing vaccine administration-routes that allows for drainage by the same lymph nodes used for priming. Higher neutralizing antibody activity and higher levels of spike-specific CD8 T-cells may have implications for protection from infection and severe disease and support general preference for ipsilateral vaccination.

FUNDING

Financial support was provided in part by the State chancellery of the Saarland to M.S.

Occurrence, resistance patterns and management of carbapenemase-producing bacteria in war-wounded refugees from Ukraine

We analysed consecutive clinical cases of infections due to carbapenemase-producing Gram-negative bacteria detected in war-wounded patients from Ukraine who were treated at one University medical centre in southwest Germany between June and December 2022. Isolates of multiresistant Gram-negative bacteria were subjected to a thorough microbiological characterisation and whole-genome sequencing. We identified five war-wounded Ukrainian patients who developed infections with NDM-1-positive Klebsiella pneumoniae. Two isolates also carried OXA-48 carbapenemases. The bacteria were resistant to novel antibiotics such as ceftazidime/avibactam and cefiderocol. Employed treatment strategies included combinations of ceftazidime/avibactam + aztreonam, colistin, or tigecycline. Whole-genome sequencing suggested transmission during primary care in Ukraine. We conclude that there is an urgent need for thorough surveillance of multiresistant pathogens in patients from war zones.

Contact times in professional football before and during the SARS-CoV-2 pandemic: Tracking data from the German Bundesliga

The global SARS-CoV-2 pandemic led to a lockdown in team sports in March 2020. Because the risk of virus transmission seems to correlate with the duration of close contacts, data on contact times are necessary to assess the risk of virus transmission in sports. In this study, an optical tracking system was used to determine contact times between players of the two highest men's professional football leagues in Germany in the 2019-20 season and in the first half of the 2020-21 season. Contacts between players were defined as being within a two-metre radius during matches and were differentiated as either match-specific or non-match-specific. In total, 918 matches with 197,087 contacts were analysed. The mean overall contact time of one-to-one situations of 36 s (SD: ± 66) before the lockdown was reduced to 30 s after the lockdown (SD: ± 60) (p < 0.0001). In professional football, contacts between two players infrequently occur within a two-metre radius, averaging less than 35 s. Only 36 player pair contacts lasted for more than 15 min (0.00018%). The mean accumulated contact time per player with all others was 10.6 ± 6.9 min per match, with a decrease from 11.6 ± 7.0 min before the lockdown to 10.0 ± 6.6 min (p < 0.0001) after lockdown in the season 2019-20. The SARS-CoV-2 pandemic has resulted in a reduction in match-specific contacts of 25%. It seems questionable if such short contacts in open-air sports may lead to considerable virus transmission.

Comparative immunogenicity and reactogenicity of heterologous ChAdOx1-nCoV-19-priming and BNT162b2 or mRNA-1273-boosting with homologous COVID-19 vaccine regimens

Comparative analyses of the immunogenicity and reactogenicity of homologous and heterologous SARS-CoV-2 vaccine-regimens will inform optimized vaccine strategies. Here we analyze the humoral and cellular immune response following heterologous and homologous vaccination strategies in a convenience cohort of 331 healthy individuals. All regimens induce immunity to the vaccine antigen. Immunity after vaccination with ChAdOx1-nCoV-19 followed by either BNT162b2 (n = 66) or mRNA-1273 (n = 101) is equivalent to or more pronounced than homologous mRNA-regimens (n = 43 BNT162b2, n = 59 mRNA-1273) or homologous ChAdOx1-nCoV-19 vaccination (n = 62). We note highest levels of spike-specific CD8 T-cells following both heterologous regimens. Among mRNA-containing combinations, spike-specific CD4 T-cell levels in regimens including mRNA-1273 are higher than respective combinations with BNT162b2. Polyfunctional T-cell levels are highest in regimens based on ChAdOx1-nCoV-19-priming. All five regimens are well tolerated with most pronounced reactogenicity upon ChAdOx1-nCoV-19-priming, and ChAdOx1-nCoV-19/mRNA-1273-boosting. In conclusion, we present comparative analyses of immunogenicity and reactogenicity for heterologous vector/mRNA-boosting and homologous mRNA-regimens.

Multiple formulations and technologies for vaccinating against SARS-CoV-2 exist but how the use of these in homologous or heterologous format impacts immunogenicity is far from clear. Here the authors compare a range of heterologous and homologous SARS-CoV-2 vaccination strategies and assess the induced humoral and cellular immune response.

Respiratory viruses dynamics and interactions: ten years of surveillance in central Europe

Background

Lower respiratory tract infections are among the main causes of death. Although there are many respiratory viruses, diagnostic efforts are focused mainly on influenza. The Respiratory Viruses Network (RespVir) collects infection data, primarily from German university hospitals, for a high diversity of infections by respiratory pathogens. In this study, we computationally analysed a subset of the RespVir database, covering 217,150 samples tested for 17 different viral pathogens in the time span from 2010 to 2019.

Methods

We calculated the prevalence of 17 respiratory viruses, analysed their seasonality patterns using information-theoretic measures and agglomerative clustering, and analysed their propensity for dual infection using a new metric dubbed average coinfection exclusion score (ACES).

Results

After initial data pre-processing, we retained 206,814 samples, corresponding to 1,408,657 performed tests. We found that Influenza viruses were reported for almost the half of all infections and that they exhibited the highest degree of seasonality. Coinfections of viruses are frequent; the most prevalent coinfection was rhinovirus/bocavirus and most of the virus pairs had a positive ACES indicating a tendency to exclude each other regarding infection.

Conclusions

The analysis of respiratory viruses dynamics in monoinfection and coinfection contributes to the prevention, diagnostic, treatment, and development of new therapeutics. Data obtained from multiplex testing is fundamental for this analysis and should be prioritized over single pathogen testing.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-13555-5.

Importance and value of adjuvanted influenza vaccine in the care of older adults from a European perspective - A systematic review of recently published literature on real-world data

BACKGROUND

There is an urgent need for improved influenza vaccines especially for older adults due to the presence of immunosenescence. It is therefore highly relevant to compare enhanced influenza vaccines with traditional influenza vaccines with respect to their effectiveness.

OBJECTIVE

To compare vaccine efficacy and effectiveness of adjuvanted influenza vaccines (aTIV/aQIV) vs. non-adjuvanted standard-dose (TIV/QIV) and high-dose (TIV-HD/QIV-HD) influenza vaccines regarding influenza-related outcomes in older adults, complementing findings from the European Centre for Disease Prevention and Control (ECDC)'s systematic review of enhanced seasonal influenza vaccines from February 2020.

METHODS

A systematic literature search was conducted in Embase and MEDLINE to identify randomised controlled trials, observational studies and systematic reviews, published since ECDC's systematic review (between 7 February 2020 and 6 September 2021). Included studies were appraised with either the Cochrane Risk of Bias tool, ROBINS-I or AMSTAR 2.

RESULTS

Eleven analyses from nine real-world evidence (RWE) studies comprising ∼53 million participants and assessing the relative vaccine effectiveness (rVE) of aTIV vs. TIV, QIV and/or TIV-HD in adults aged ≥65 years over the 2006/07-2008/09 and 2011/12-2019/20 influenza seasons were identified. Nine analyses found that aTIV was significantly more effective than TIV and QIV in reducing influenza-related outcomes by clinical setting and suspected influenza outbreaks (rVE ranging from 7.5% to 25.6% for aTIV vs. TIV and 7.1% to 36.3% for aTIV vs. QIV). Seven analyses found similar effectiveness of aTIV vs. TIV-HD in reducing influenza-related medical encounters, inpatient stays and hospitalisations/emergency room visits. In three analyses, aTIV was significantly more effective than TIV-HD in reducing influenza-related medical encounters and office visits (rVE ranging from 6.6% to 16.6%). Risk of bias of identified studies was moderate to high.

CONCLUSIONS

Our study suggests that both adjuvanted and high-dose vaccines are effective alternatives for vaccination programmes in older adults and preferable over conventional standard-dose vaccines.

Central retinal artery occlusion following COVID-19 vaccine administration

Introduction

Increased risk of thromboembolic events has been associated with SARS-CoV-2 infections and more recently, with COVID-19 vaccination. To date, however, there are no reports of an association between the COVID-19 vaccination and retinal artery occlusions. We report a case of a patient who developed central retinal artery occlusion (CRAO) 2 days following the administration of the AstraZeneca COVID-19 vaccine.

Case description

A 76-year-old woman presented to our Department of Ophthalmology complaining of painless vision loss in her left eye 48 hours after she had received her first dose of the AstraZeneca COVID-19 vaccine. Her best-corrected visual acuity was only hand movement in the left eye. Left eye ophthalmologic examination showed the presence of arterial narrowing and a cherry red spot. Optical coherence tomography showed severe macular swelling of the inner retinal layers in the left eye Fluorescein angiography performed the following day confirmed the diagnosis. The cardiovascular examination including Holter ECG was unremarkable. Complete blood count was within normal limits, without thrombocytopenia. A subsequent cerebral CT and CT-angiography scans did not show any other acute vascular event. Doppler angiography of the carotid artery was performed and showed normal flow without clinically significant plaques, stenoses, occlusions or dissections.

Conclusions

To our knowledge, this is the first case of an isolated CRAO following the administration of the AstraZeneca COVID-19 vaccine. Further studies are needed to evaluate this potential association and identify pathophysiologic relationships between COVID-19 vaccinations and CRAO.

Estimation of Reduction in Influenza Vaccine Effectiveness Due to Egg-Adaptation Changes-Systematic Literature Review and Expert Consensus

BACKGROUND

Influenza vaccines are the main tool to prevent morbidity and mortality of the disease; however, egg adaptations associated with the choice of the manufacturing process may reduce their effectiveness. This study aimed to estimate the impact of egg adaptations and antigenic drift on the effectiveness of trivalent (TIV) and quadrivalent (QIV) influenza vaccines.

METHODS

Nine experts in influenza virology were recruited into a Delphi-style exercise. In the first round, the experts were asked to answer questions on the impact of antigenic drift and egg adaptations on vaccine match (VM) and influenza vaccine effectiveness (IVE). In the second round, the experts were presented with the data from a systematic literature review on the same subject and aggregated experts' responses to round one questions. The experts were asked to review and confirm or amend their responses before the final summary statistics were calculated.

RESULTS

The experts estimated that, across Europe, the egg adaptations reduce, on average, VM to circulating viruses by 7-21% and reduce IVE by 4-16%. According to the experts, antigenic drift results in a similar impact on VM (8-24%) and IVE (5-20%). The highest reduction in IVE was estimated for the influenza virus A(H3N2) subtype for the under 65 age group. When asked about the frequency of the phenomena, the experts indicated that, on average, between the 2014 and 19 seasons, egg adaptation and antigenic drift were significant enough to impact IVE that occurred in two and three out of five seasons, respectively. They also agreed that this pattern is likely to reoccur in future seasons.

CONCLUSIONS

Expert estimates suggest there is a potential for 9% on average (weighted average of "All strains" over three age groups adjusted by population size) and up to a 16% increase in IVE (against A(H3N2), the <65 age group) if egg adaptations that arise when employing the traditional egg-based manufacturing process are avoided.

Diversity of antibody responses after influenza infection or vaccination-Needed or nice to have?

Gärtner and Sester contextualize recent findings on natural and vaccine‐induced immunity towards influenza in transplant recipients including implications for other vaccines. Hirzel et al.'s article is on page 2709.

Immunogenicity and reactogenicity of heterologous ChAdOx1 nCoV-19/mRNA vaccination

Heterologous priming with the ChAdOx1 nCoV-19 vector vaccine followed by boosting with a messenger RNA vaccine (BNT162b2 or mRNA-1273) is currently recommended in Germany, although data on immunogenicity and reactogenicity are not available. In this observational study we show that, in healthy adult individuals (n = 96), the heterologous vaccine regimen induced spike-specific IgG, neutralizing antibodies and spike-specific CD4 T cells, the levels of which which were significantly higher than after homologous vector vaccine boost (n = 55) and higher or comparable in magnitude to homologous mRNA vaccine regimens (n = 62). Moreover, spike-specific CD8 T cell levels after heterologous vaccination were significantly higher than after both homologous regimens. Spike-specific T cells were predominantly polyfunctional with largely overlapping cytokine-producing phenotypes in all three regimens. Recipients of both the homologous vector regimen and the heterologous vector/mRNA combination reported greater reactogenicity following the priming vector vaccination, whereas heterologous boosting was well tolerated and comparable to homologous mRNA boosting. Taken together, heterologous vector/mRNA boosting induces strong humoral and cellular immune responses with acceptable reactogenicity profiles.

In healthy adults, booster vaccination with an mRNA vaccine, irrespective of the vaccine used for the first dose, was well tolerated and elicited higher levels of spike-specific antibodies and spike-specific T cells than booster vaccination with ChAdOx1 nCov-19.

Incidence and Prevalence of Borrelia burgdorferi Antibodies in Male Professional Football Players

OBJECTIVE

Infections with Borrelia burgdorferi can cause Lyme disease with multiorganic involvement such as (myo)carditis or joint manifestations. Musculoskeletal complaints possibly mimicking some of these symptoms are common among elite athletes. This study aimed to determine seroprevalence and incidence of B. burgdorferi antibodies in professional football players.

DESIGN

Prospective observational study.

SETTING

Healthy professional football players.

PARTICIPANTS

Five hundred thirty-five men in the first and second German league.

INTERVENTIONS

Two screening assays were used to examine immunoglobulin M (IgM) and immunoglobulin G (IgG) against B. burgdorferi: an enzyme immunoassay (EIA) and a chemiluminescence assay (CLIA). In case of a positive or equivocal result, an immunoblot including in vivo antigens was performed.

MAIN OUTCOME MEASURES

Course of IgM and IgG against B. burgdorferi in overall 1529 blood samples.

RESULTS

A total of 96.4% of all results were concordant between EIA and CLIA. Considering only samples with identical results in both assays, prevalence was 1.6%. A positive IgM was detected in 2.3%. No player showed any symptoms of Lyme disease. A seroconversion to IgG was not found. Three players developed a positive IgM corresponding to an incidence of 1032/100 000 person-years. Depending on the assay, 49% to 75% of positive or equivocal screening results could not be confirmed by immunoblot.

CONCLUSIONS

Seroprevalence and incidence of B. burgdorferi among healthy male professional football players are low. Therefore, infections with B. burgdorferi have to be regarded a rare differential diagnosis in professional football in Central Europe. The low confirmation rate of positive screening assays points to an unspecific immune activation.

Combined antibiotic stewardship and infection control measures to contain the spread of linezolid-resistant Staphylococcus epidermidis in an intensive care unit

Background

The unrestricted use of linezolid has been linked to the emergence of linezolid-resistant Staphylococcus epidermidis (LRSE). We report the effects of combined antibiotic stewardship and infection control measures on the spread of LRSE in an intensive care unit (ICU).

Methods

Microbiological data were reviewed to identify all LRSE detected in clinical samples at an ICU in southwest Germany. Quantitative data on the use of antibiotics with Gram-positive coverage were obtained in defined daily doses (DDD) per 100 patient-days (PD). In addition to infection control measures, an antibiotic stewardship intervention was started in May 2019, focusing on linezolid restriction and promoting vancomycin, wherever needed. We compared data from the pre-intervention period (May 2018–April 2019) to the post-intervention period (May 2019–April 2020). Whole-genome sequencing (WGS) was performed to determine the genetic relatedness of LRSE isolates.

Results

In the pre-intervention period, LRSE were isolated from 31 patients (17 in blood cultures). The average consumption of linezolid and daptomycin decreased from 7.5 DDD/100 PD and 12.3 DDD/100 PD per month in the pre-intervention period to 2.5 DDD/100 PD and 5.7 DDD/100 PD per month in the post-intervention period (p = 0.0022 and 0.0205), respectively. Conversely, vancomycin consumption increased from 0.2 DDD/100 PD per month to 4.7 DDD/100 PD per month (p < 0.0001). In the post-intervention period, LRSE were detected in 6 patients (4 in blood cultures) (p = 0.0065). WGS revealed the predominance of one single clone.

Conclusions

Complementing infection control measures by targeted antibiotic stewardship interventions was beneficial in containing the spread of LRSE in an ICU.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13756-021-00970-3.

Respiratory viral infections in solid organ transplant recipients: New insights from multicenter data

A new study from Mombelli et al. (page 1789) sheds light on viral respiratory infections in solid organ transplant recipients, focusing on consequences of these infections and potential interventions for prevention.

Prophylaxis and treatment of influenza: options, antiviral susceptibility, and existing recommendations

Influenza viruses of types A and B attack 5-10% of adults and 20-30% of children, thereby causing millions of acute respiratory infections in Germany annually. A significant number of these infections are associated with complications such as pneumonia and bacterial superinfections that need hospitalization and might lead to death. In addition to vaccines, drugs were developed that might support influenza prevention and that can be used to treat influenza patients. The timely application of anti-influenza drugs can inhibit virus replication, help reduce and shorten the symptoms, and prevent death as well as virus transmission. This review concisely describes the mechanism of action, the potential for prophylactic and therapeutic use, and the knowledge on resistance of anti-influenza drugs approved today. However, the main aim is to give an overview on the recommendations available in Germany for the proper use of these drugs. In doing so, the recommendations published in statements and guidelines of medical societies as well as the German influenza pandemic preparedness plan are summarized with the consideration of specific circumstances and groups of patients.

Successful return to professional men's football (soccer) competition after the COVID-19 shutdown: a cohort study in the German Bundesliga

OBJECTIVES

To evaluate the restart of the German Bundesliga (football (soccer)) during the COVID-19 pandemic from a medical perspective.

METHODS

Participants were male professional football players from the two highest German leagues and the officials working closely with them. Our report covers nine match days spread over 9 weeks (May to July 2020). Daily symptom monitoring, PCR testing for SARS-CoV-2 RNA twice weekly, and antibody tests (on two occasions-early during the phase in May 2020 and in the week of the last match) were conducted. Target variables were: (1) onset of typical COVID-19 symptoms, (2) positive PCR results, and (3) IgG seroconversion against SARS-CoV-2. All detected seroconversions were controlled by neutralisation tests.

FINDINGS

Suspicious symptoms were reported for one player; an immediate additional PCR test as well as all subsequent diagnostic and antibody tests proved negative for coronavirus. Of 1702 regularly tested individuals (1079 players, 623 officials members), 8 players and 4 officials tested positive during one of the first rounds of PCR testing prior to the onset of team training, 2 players during the third round. No further positive results occurred during the remainder of the season. 694 players and 291 officials provided two serum samples for antibody testing. Nine players converted from negative/borderline to positive (without symptoms); two players who initially tested positive tested negative at the end of the season. 22 players remained seropositive throughout the season. None of the seroconversions was confirmed in the neutralisation test.

CONCLUSION

Professional football training and matches can be carried out safely during the COVID-19 pandemic. This requires strict hygiene measures including regular PCR testing.

Timing of Vaccination after Training: Immune Response and Side Effects in Athletes

OBJECTIVES

Influenza vaccination was used to assess whether induction of immunity or side effects are influenced by the timing of the last training session before vaccination.

METHODS

Forty-five healthy athletes (36 male, 23 ± 8 yr, ≥5 training sessions per week, predominantly national competition level) were vaccinated with the tetravalent influenza vaccine; blood samples were collected immediately before and 1, 2, and 26 wk after vaccination. Athletes were randomly assigned to vaccination within 2 h after the last training session versus after 24-26 h. Influenza-specific T cells were quantified after stimulation with the vaccine based on intracellular cytokine staining. Antibodies (IgA, IgG, IgM) were quantified by enzyme-linked immunosorbent assay and neutralization assay. Participants documented resulting side effects and training restrictions using a standardized diary.

RESULTS

Both groups showed an increase in influenza-reactive CD4 T-cell levels, which peaked 1 wk after vaccination (fold changes to baseline; median (interquartile range), 3.7 (3.0-5.4; P < 0.001) in the 2-h group; 4.6 (2.8-7.4; P < 0.001) in the 26-h group) with no difference between groups (P = 0.52). Influenza-specific antibodies showed a significant increase after vaccination in both groups (at least 1.4-fold, each P < 0.001, no group differences; P = 0.24-0.97 for different antibody types). Only antibodies toward the Brisbane strain showed a trend toward significant differences in neutralization titers between groups (4-fold (2-17.8) in the 2-h group, 16-fold (4-32.9) in the 26-h group; P = 0.06), whereas other specificities did not differ (P = 0.16-0.72). No intergroup differences were found for side effects; no athlete reported a loss of training time due to the vaccination or its side effects.

CONCLUSION

Infection prophylaxis in elite athletes by influenza vaccination seems to be effective and safe. Timing of vaccination after prior training does not seem to require specific constraints.

High levels of SARS-CoV-2-specific T cells with restricted functionality in severe courses of COVID-19

BACKGROUND

Patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) differ in the severity of disease. We hypothesized that characteristics of SARS-CoV-2–specific immunity correlate with disease severity.

METHODS

In this study, SARS-CoV-2–specific T cells and antibodies were characterized in uninfected controls and patients with different coronavirus disease 2019 (COVID-19) disease severity. SARS-CoV-2–specific T cells were flow cytometrically quantified after stimulation with SARS-CoV-2 peptide pools and analyzed for expression of cytokines (IFN-γ, IL-2, and TNF-α) and markers for activation, proliferation, and functional anergy. SARS-CoV-2–specific IgG and IgA antibodies were quantified using ELISA. Moreover, global characteristics of lymphocyte subpopulations were compared between patient groups and uninfected controls.

RESULTS

Despite severe lymphopenia affecting all major lymphocyte subpopulations, patients with severe disease mounted significantly higher levels of SARS-CoV-2–specific T cells as compared with convalescent individuals. SARS-CoV-2–specific CD4⁺ T cells dominated over CD8⁺ T cells and closely correlated with the number of plasmablasts and SARS-CoV-2–specific IgA and IgG levels. Unlike in convalescent patients, SARS-CoV-2–specific T cells in patients with severe disease showed marked alterations in phenotypical and functional properties, which also extended to CD4⁺ and CD8⁺ T cells in general.

CONCLUSION

Given the strong induction of specific immunity to control viral replication in patients with severe disease, the functionally altered characteristics may result from the need for contraction of specific and general immunity to counteract excessive immunopathology in the lung.

FUNDING

The study was supported by institutional funds to MS and in part by grants of Saarland University, the State of Saarland, and the Rolf M. Schwiete Stiftung.

COVID-19 patients with severe disease have higher levels of SARS-CoV-2 specific T-cells as compared to convalescent individuals.

Clostridioides (Clostridium) difficile Pacemaker Infection

Clostridioides difficile is the leading cause of antibiotic-associated nosocomial diarrhea, but extra-intestinal manifestations are rare. We describe the first documented case of bacteraemia with pacemaker pocket and lead infection with the toxigenic C. difficile ribotype 014 with a lack of abdominal symptoms. The patient underwent pacemaker extraction and treatment with intravenous and oral vancomycin. Genotyping and molecular subtyping revealed clonality between pacemaker and intestinal isolates. This case illustrates the risk of intravascular device infections due to C. difficile. Even asymptomatic C. difficile colonization might pose a risk for prosthetic material infection.

Do written diagnosis-treatment recommendations on microbiological test reports improve the management of Staphylococcus aureus bacteremia? A single-center, retrospective, observational study

The objective of this study was to assess the impact of microbiological test reports that provide specific written recommendations on the appropriate management of Staphylococcus aureus bacteremia (SAB). We performed a retrospective analysis of laboratory and clinical data of all SAB patients treated at one German University hospital, 2012-2015. Among 467 included patients, methicillin-resistant S. aureus (MRSA) accounted for 15.2% of all SAB cases. All-cause in-hospital mortality was 25.2%, and was significantly elevated in individuals aged >55 years, in MRSA bacteremia and if the source of infection remained unidentified. Focus identification was achieved in 71.1%, with the most prevalent foci being catheter-associated bloodstream infection (23.1%), soft tissue infection (15.4%), osteomyelitis (5.1%) and endocarditis (4.9%). Standardized written recommendations on microbiological test reports led to a significant increase of transesophageal echocardiography, additional imaging studies for focus identification and more frequent follow-up blood cultures, but no significant effect on mortality was observed.

Elite athletes on regular training show more pronounced induction of vaccine-specific T-cells and antibodies after tetravalent influenza vaccination than controls

Compliance of elite athletes with vaccination recommendations is low mainly based on concerns about side-effects and perceived poor vaccine efficacy due to continued physical training. We therefore employed seasonal influenza vaccination to investigate the effect of regular physical training on vaccine-induced cellular and humoral immunity in elite athletes and controls. Lymphocyte subpopulations and vaccine-specific T-cells were quantified and functionally characterized from 45 athletes and 25 controls before, and 1, 2 and 26 weeks after vaccination. Moreover, influenza-specific antibodies and their neutralizing function were quantified. Both groups showed a significant increase in vaccine-reactive CD4 T-cell levels which peaked one week after vaccination (p < 0.0001). The increase was significantly more pronounced in athletes (4.1-fold) compared to controls (2.3-fold; p = 0.0007). The cytokine profile changed from multifunctional T-cells co-producing IFNγ, IL-2 and TNFα to cells with restricted cytokine expression. This change in functionality was associated with a significant increase in CTLA-4 expression (p < 0.0001), which again was more pronounced in athletes. Likewise, the increase in neutralizing antibodies was stronger in athletes (p = 0.004 for H1N1; p = 0.032 for H3N2). In conclusion, both groups mounted a strong vaccine-specific cellular and humoral immunity after standard vaccination. The more pronounced increase in specific T-cells and neutralizing antibodies indicates that high frequency and intensity of training enhance vaccine-responses in elite athletes.

Quality assurance for genotyping and resistance testing of Clostridium (Clostridioides) difficile isolates - Experiences from the first inter-laboratory ring trial in four German speaking countries

Clostridium (Clostridioides) difficile is a major cause of nosocomial diarrhoea. A first inter-laboratory ring trial was performed in four European countries to evaluate the genotyping and antibiotic susceptibility testing (AST) accuracy. Six C. difficile isolates representing the epidemiologic important ribotypes (RT), RT001, RT002, RT010, RT014, RT027, and RT078 were blinded and send to 21 participating laboratories. Participants tested the samples with their genotyping and AST methods in use for concordance with reference. A total of 21 genotyping- and 14 antimicrobial susceptibility data sets were obtained. Ribotyping (11 participants) correctly identified most RTs (median 91% concordance rate) except for RT002, which was misidentified in 4/11 reports. However, this isolate was correctly asserted to RT002 after an update of a publicly available ribotyping database. Multilocus sequence typing, surface layer sequence typing, DNA microarray based genotyping, and whole genome sequencing, which were used by 1-3 participants, identified all six isolates correctly. AST was done by epsilometry by the participants and compared to agar dilution data determined by the coordinating reference centre. Susceptibilities against metronidazole, moxifloxacin, and vancomycin were correctly identified in 235 of 237 cases and in accordance to agar dilution as the gold standard. Genotyping of the C. difficile test strains revealed a remarkable high concordance on the level of ribotypes with a wide variety of methods. Epsilometry appears to be a reliable method for AST of C. difficile isolates in routine clinical microbiology laboratories.

Vaccinations during pregnancy: a call to sting into action

Safety and efficacy of vaccinations during pregnancy have been a matter of debate. In the aftermath of the 2009 H1N1 influenza pandemic, a growing body of research has emerged, which points toward the importance of adhering to influenza vaccination recommendations for pregnant women. The same applies for vaccination against pertussis. Some vaccines (e.g., live attenuated) are still contraindicated during pregnancy. However, data indicate that these vaccines do not result in fetal impairment when administered accidentally during pregnancy. In the following, we provide a review on vaccination-related safety and efficacy aspects in pregnant women, shedding some light on potential barriers that stymie vaccination uptake among pregnant women and introducing strategies to overcome these barriers.

Rapid reconstitution of CMV-specific T-cells after stem-cell transplantation

OBJECTIVE

As reconstitution of virus-specific T-cells is critical to control cytomegalovirus (CMV)-viremia following stem-cell transplantation (SCT), we characterized the dynamics in CMV-specific T-cell reconstitution after SCT.

METHODS

Cytomegalovirus-specific T-cells from 51 SCT-recipients were prospectively quantified and phenotypically characterised by intracellular cytokine-staining after specific stimulation and HLA class-I-specific pentamers using flow cytometry.

RESULTS

Cytomegalovirus-specific CD4 T-cells reconstituted after a median of 2.3 (IQR, 2.0-3.0) weeks following autografting, and 4.0 (IQR, 3.0-5.6) weeks after allografting, with CMV-specific T-cells originating from donors and/or recipients. The time for reconstitution of CMV-specific CD4 and CD8 T-cells did not differ (P = .58). Factors delaying the time to initial reconstitution of CMV-specific CD4 T-cells included a negative recipient serostatus (P = .016) and CMV-viremia (P = .026). Percentages of CMV-specific CD4 T-cells significantly increased over time and reached a plateau after 90 days (P = .043). Relative CMV-specific CD4 T-cell levels remained higher in long-term transplant recipients compared with those in controls (P < .0001). However, due to persisting lymphopenia, absolute numbers of CMV-specific T-cells were similar as in controls.

CONCLUSION

Cytomegalovirus-specific T-cells rapidly reconstitute after SCT and their percentages remain high in the long term. In the face of persistent lymphopenia, this results in similar absolute numbers of CMV-specific T-cells as in controls to ensure sufficient pathogen control.

Pre- and perioperative aspects of dermatosurgery

Dermatosurgery occupies an exceptional position among all surgical disciplines. Above all, this includes the fact that, with very few exceptions, the vast majority of surgical interventions can be performed under local or regional anesthesia, usually in smaller procedure rooms that are spatially separated from larger operating suites. Thus, peri- and postinterventional patient monitoring is the responsibility of the dermatosurgeon and his team. Though inherently smaller, this team still has to observe numerous perioperative requirements that - in larger surgical specialties - would be attended to by a host of various specialists working in concert. Said requirements include hygienic aspects, knowledge concerning pre- and intraoperative patient monitoring, managing surgical site infections, adequate postsurgical pain management, as well as detailed pharmacological knowledge with respect to common local anesthetics and the toxic and allergic reactions associated therewith. Not only does this require interdisciplinary collaboration and shared responsibility for the patient. It also necessitates the development and implementation of quality-oriented and evidence-based guidelines that, in the dermatosurgical setting, usually extend far beyond the scope of the specialty per se. The objective of the present CME article is the condensed presentation of interdisciplinary aspects relating to the most important perioperative issues.

CTLA-4-expression on VZV-specific T cells in CSF and blood is specifically increased in patients with VZV related central nervous system infections

VZV-reactivation may lead to symptomatic central nervous system (CNS) diseases, but identification of VZV as causative pathogen of CNS-diseases is challenging. This study was performed to characterize VZV-specific T cells from cerebrospinal fluid (CSF) and blood of patients with active CNS-disease and to determine whether this may improve differential diagnosis. 27 patients with pleocytosis in the CSF were recruited and classified into three groups (10 VZV-related, 10 non-VZV-related, 7 unclear). VZV-specific CD4⁺ T cells were quantified in CSF and blood after simultaneous stimulation with a VZV-antigen lysate and detection of cytokines (IFN-γ, IL-2, TNF-α) and CTLA-4. Polyclonal stimulation served as positive control. VZV-specific CD4⁺ T-cell frequencies were highest in both CSF (p = 0.0001) and blood (p = 0.011) of patients with VZV-infection, and were enriched at the site of infection (p = 0.002). While cytokine-expression profiles only showed minor differences between the groups, CTLA-4-expression levels on VZV-specific T cells from CSF and blood were significantly increased in VZV-related CNS-infections (p = 0.0002 and p<0.0001) and clearly identified VZV-related CNS-diseases (100% sensitivity and 100% specificity). Polyclonally stimulated T cells did not show any quantitative and phenotypical differences between the groups. Increased frequency and CTLA-4-expression of VZV-specific T cells from CSF or blood are specifically found in patients with VZV-related CNS-infection.

Prä- und perioperative Aspekte der Versorgung dermatochirurgischer Patienten

Die Dermatochirurgie nimmt hinsichtlich vieler Punkte eine Sonderstellung unter den operativen Fächern ein. Hierzu gehört in erster Linie die Tatsache, dass bis auf wenige Ausnahmen fast alle Eingriffe traditionell in Lokal- bzw. Regionalanästhesie und oft auch in räumlich-infrastruktureller Trennung von den großen Zentral-Operationssälen stattfinden können. Die peri- und postoperative Überwachung obliegt dabei dem dermatochirurgischen Operationsteam. Das sui generis kleinere OP-Team hat somit eine ganze Reihe perioperativer Notwendigkeiten zu beachten, um die sich in den "großen" chirurgischen Fächern eine Vielzahl verschiedener beteiligter Fachgruppen gemeinsam kümmern. Hierzu gehören neben Hygieneaspekten, Kenntnissen in der Überwachung der Patienten sowie dem Aspekt der surgical site infections auch Fragen zur postoperativen Schmerztherapie sowie detailliertes pharmakologisches Wissen über die zur Anwendung kommenden Lokalanästhetika und das Handling der damit assoziierten toxischen und allergischen Reaktionen. Eine interdisziplinäre Zusammenarbeit und Verantwortung für den Patienten ist notwendig und erfordert die Erarbeitung und Umsetzung qualitätsorientierter und evidenzbasierter Handlungsanweisungen, die im dermatochirurgischen OP-Setting meist weit über das eigentliche Fach hinausgehen. Ziel dieses Weiterbildungsartikels soll die komprimierte Darstellung der genannten fachübergreifenden Standpunkte bezüglich der wichtigsten perioperativen Aspekte sein.

Vaccination in elite athletes

Public health vaccination guidelines cannot be easily transferred to elite athletes. An enhanced benefit from preventing even mild diseases is obvious but stronger interference from otherwise minor side effects has to be considered as well. Thus, special vaccination guidelines for adult elite athletes are required. In most of them, protection should be strived for against tetanus, diphtheria, pertussis, influenza, hepatitis A, hepatitis B, measles, mumps and varicella. When living or traveling to endemic areas, the athletes should be immune against tick-borne encephalitis, yellow fever, Japanese encephalitis, poliomyelitis, typhoid fever, and meningococcal disease. Vaccination against pneumococci and Haemophilus influenzae type b is only relevant in athletes with certain underlying disorders. Rubella and papillomavirus vaccination might be considered after an individual risk–benefit analysis. Other vaccinations such as cholera, rabies, herpes zoster, and Bacille Calmette–Guérin (BCG) cannot be universally recommended for athletes at present. Only for a very few diseases, a determination of antibody titers is reasonable to avoid unnecessary vaccinations or to control efficacy of an individual’s vaccination (especially for measles, mumps, rubella, varicella, hepatitis B and, partly, hepatitis A). Vaccinations should be scheduled in a way that possible side effects are least likely to occur in periods of competition. Typically, vaccinations are well tolerated by elite athletes, and resulting antibody titers are not different from the general population. Side effects might be reduced by an optimal selection of vaccines and an appropriate technique of administration. Very few discipline-specific considerations apply to an athlete’s vaccination schedule mainly from the competition and training pattern as well as from the typical geographical distribution of competitive sites.

A pseudo-outbreak due to Acinetobacter species (GIM-1) contamination of the pneumatic transport system of a Large University Hospital

OBJECTIVE

To establish the source and contamination routes resulting in positive clinical and surveillance microbiological cultures with carbapenem-resistant, GIM-1 metallo-β-lactamase-positive Acinetobacter pitii and Acinetobacter radioresistens from 21 patients in 8 departments.

DESIGN

Retrospective, descriptive study.

SETTING

A 1,300-bed tertiary care academic medical facility consisting of 90 buildings linked by a pneumatic transport system (PTS).

METHODS

Microbiological workup of the cluster strains included matrix-assisted laser desorption/ionization time-of-flight species identification, phenotypic carbapenemase tests, polymerase chain reaction-based genotyping of carbapenemase, and pulsed-field gel electrophoresis. Outbreak management procedures were employed according to institutional regulations.

RESULTS

The rarity of GIM-1 Acinetobacter species in the hospital and region, the lack of epidemiological links between patients, and the fact that in some patients the apparent colonization was clearly nonnosocomial prompted the suspicion of a pseudo-outbreak. Numerous environmental cultures were positive for GIM-1-positive Acinetobacter (including archived sample requisition forms, PTS capsules, cultures from line-diverter and dispenser stations, and sterilized transport capsules following PTS delivery). Moreover, it was observed that condensation fluid from subterranean PTS tubing resulted in water entry in PTS capsules, possibly conferring specimen contamination. After extensive system disinfection, environmental surveys of the PTS were negative, and no further positive patient specimens were encountered.

CONCLUSIONS

This is the first report of a PTS-associated pseudo-outbreak. The large number of falsely positive patient-related specimens in conjunction with the potential hazard of airborne and contact spread of multidrug-resistant microorganisms (in this case, GIM-1 carbapenem-resistant Acinetobacter species) underscores the need for implementation of infection control-based monitoring and operating procedures in a hospital PTS.

Ill-defined germinal centers and severely reduced plasma cells are histological hallmarks of lymphadenopathy in patients with common variable immunodeficiency

Given the severely reduced numbers of circulating class-switched memory B cells and plasmablasts in patients with common variable immunodeficiency (CVID) the germinal center (GC) reaction as the source of both populations is expected to be disturbed in many CVID patients. Therefore immunohistochemical studies were performed on lymph node (LN) biopsies from ten CVID patients with benign lymphoproliferation. According to the Sander classification the majority of patients presented with reactive lymphoid hyperplasia (7/10), 6/10 showed granulomatous inflammation. All cases showed some normal GCs but in 9/10 these concurred to a varying degree with hyperplastic, ill-defined GCs in the same LN. The percentage of ill-defined GCs correlated significantly with the percentage of circulating CD21(low) B cells suggesting a common origin of both immune reactions. In 9/10 CVID LNs significantly higher numbers of infiltrating CD8+ T cells were found in GCs of CVID patients compared to controls, but no HHV-8 and only in 2/10 LNs EBV infection was detected. Class switched plasma cells (PCs) were severely reduced in 8/10 LNs and if present, rarely found in the medulla of the LN. Based on the presence of large GCs in all examined patients, the reduction of circulating memory B cells and PCs points towards a failure of GC output rather than GC formation in CVID patients with lymphadenopathy.

PD-1 analysis on CD28(-) CD27(-) CD4 T cells allows stimulation-independent assessment of CMV viremic episodes in transplant recipients

Expression of the inhibitory receptor programmed death 1 (PD-1) on cytomegalovirus (CMV)-specific CD4 T cells defines a phenotype associated with CMV viremia in transplant recipients. Moreover, CD28(-) CD27(-) double negativity is known as a typical phenotype of CMV-specific CD4 T cells. Therefore, the co-expression of inhibitory receptors on CD28(-) CD27(-) CD4 T cells was assessed as a rapid, stimulation-independent parameter for monitoring CMV complications after transplantation. Ninety-three controls, 67 hemodialysis patients and 81 renal transplant recipients were recruited in a cross-sectional and longitudinal manner. CMV-specific CD4 T cell levels quantified after stimulation were compared to levels of CD28(-) CD27(-) CD4 T cells. PD-1 and cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) expression on CD28(-) CD27(-) CD4 T cells were related to viremia. A percentage of ≥0.44% CD28(-) CD27(-) CD4 T cells defined CMV seropositivity (93.3% sensitivity, 97.1% specificity), and their frequencies correlated strongly with CMV-specific CD4 T cell levels after stimulation (r = 0.73, p < 0.0001). Highest PD-1 expression levels on CD28(-) CD27(-) CD4 T cells were observed in patients with primary CMV viremia and reactivation (p < 0.0001), whereas CTLA-4 expression was only elevated during primary CMV viremia (p < 0.05). Longitudinal analysis showed a significant increase in PD-1 expression in relation to viremia (p < 0.001), whereas changes in nonviremic patients were nonsignificant. In conclusion, increased PD-1 expression on CD28(-) CD27(-) CD4 T cells correlates with CMV viremia in transplant recipients and may serve as a specific, stimulation-independent parameter to guide duration of antiviral therapy.

Identification of optimal target gene regions for hepatitis B virus genotyping by DNA sequencing

OBJECTIVES

DNA sequencing is the gold standard for hepatitis B virus (HBV) genotyping. We investigated the intergenotypic discriminatory capabilities of various target gene regions over the entire HBV genome, introducing a novel data evaluation approach generally applicable in viral genotyping.

METHODS

Complete genome sequences of seventy HBV variants obtained from the sera of 50 Syrian patients were determined and assigned GenBank accession No. from JN257148 to JN257217. Nucleotide sequence contigs were analyzed together with the NCBI reference genome set of HBV genotypes. Nine target gene regions were analyzed by phylogenetic and scored BLAST analyses. Thirty-one overlapping 300-bp sequence segments over the entire genome were also analyzed using a scored BLAST analysis, and intergenotypic discriminatory capabilities were statistically estimated for each.

RESULTS

Intergenotype discrimination was extremely significant when targeting either the complete genome, the entire coding sequence of either P or S genes, or any 300-bp sequence segment over the coding sequences of S protein or the polymerase N-terminal domain. Interestingly, intergenotypic discriminatory capability correlated negatively with intragenotype variation.

CONCLUSIONS

The intragenotypic conservation of certain target gene regions determines the intergenotypic discriminatory capability and allows reliable genotyping with relatively short segments. Our referential genome-wide tabulated guide allows for selecting candidate target gene regions for sequencing-based HBV genotyping. © 2013 S. Karger AG, Basel.

Heterozygosity for the alpha1-antitrypsin Z allele may confer genetic risk of cholangiocarcinoma

BACKGROUND

Alpha1-antitrypsin (α1AT) deficiency caused by Z allele homozygosity represents a well-established risk factor for hepatocellular carcinoma. Previous studies have also implicated α1AT Z heterozygosity in cholangiocarcinogenesis.

AIM

To assess the 'common' Z and S alleles as well as the promoter variant rs8004738 for association with cholangiocarcinoma.

METHODS

We genotyped 182 Caucasian patients and 350 controls for rs28929474 (Z), rs17580 (S) and the variant rs8004738. Exploratory analyses were performed in relation to gender and cholangiocarcinoma localisation.

RESULTS

rs28929474 was significantly enriched in the cholangiocarcinoma group (4.1 vs. 1.7%; OR 2.46, 95% CI 1.14-5.32; Bonferroni corrected p(c) = 0.036), reinforced by Armitage trend testing (OR 2.53; p(c) = 0.032). The rs8004738 (promoter) minor allele tended to be overrepresented in Z heterozygotes (30.0 vs. 16.7%: P = 0.13). Exploratory data analyses suggested a high genetic risk for extrahepatic tumour localisation (OR 3.0; p(c) = 0.016) and potentially female Z allele carriers (OR 3.37; unadjusted P = 0.022, p(c) = 0.088).

CONCLUSIONS

These data point to a novel role of α1AT Z heterozygosity as a potential genetic susceptibility factor for cholangiocarcinoma formation and suggest a contribution of aberrant α1AT function in biliary carcinogenesis. However, given the overall low rs28929474 minor allele frequency, larger studies are warranted to confirm and extend our findings.

A cost-benefit analysis of blood donor vaccination as an alternative to additional DNA testing for reducing transfusion transmission of hepatitis B virus

A survey-based, cost-benefit analysis was performed comparing blood screening strategies with vaccination strategies for the reduction of transfusion transmission of HBV. 231 whole blood donors and 126 apheresis donors were eligible and completed a questionnaire detailing their donation habits. The cost-benefit analysis included current mandatory HBV testing (HbsAg+anti-Hbc, A1), A1 with additional nucleic acid testing (NAT) for minipool (A2) or individual donation testing (A3), as well as HBV vaccination strategies using time-dependant (B1) or titre dependent booster vaccination solely (B2), or B2 in addition to current mandatory testing procedures (B3). Different cost models were applied using a 5% rate of discount. Absolute costs for current mandatory testing procedures (A1) over 20 years in Germany were €1009 million. Additional NAT would lead to incremental costs of 43% (A2) or 339% (A3), respectively. Vaccination strategies B1 and B2 showed cost-reductions relative to A1 of 30% and 14%, respectively. The number of remaining HBV infections could be reduced from 360 (for A1) to 13, using vaccination, compared with 144 or 105 remaining infections for A2 or A3, respectively. Absolute cost per prevented infection is similar (€2.0 million) for A2 and B3. HBV vaccination offers the near-elimination of transfusion infections while representing a potential cost-reduction.

Comparative evaluation of published cytomegalovirus primers for rapid real-time PCR: which are the most sensitive?

Standardization of human cytomegalovirus (CMV) PCR is highly recommended. As primer design is essential for PCR sensitivity, this study evaluated all published CMV primer pairs to identify the most sensitive for single-round real-time PCR. PubMed (1993-2004) was searched for original papers aimed at CMV PCR. Fifty-seven papers were identified revealing 82 different primer pairs. Of these, 17 primer sets were selected for empirical study, as they were either used in real-time PCR or were evaluated comparatively by conventional PCR. After optimizing the PCR conditions, these primer sets were evaluated by real-time PCR using a SYBR Green format. Analytical sensitivities were assessed by testing the reference standard CMV strain AD169. A blast search was performed to identify mismatches with published sequences. Additionally, 60 clinical samples were tested with the three primer sets showing highest analytical sensitivity and the best match to all CMV strains. Three primer sets located in the glycoprotein B (UL55) gene region were found to be the most sensitive using strain AD169. However, two of these showed a considerable number of mismatches with clinical isolates in a blast search. Instead, two other pairs from the lower matrix phosphoprotein (UL83) gene and DNA polymerase (UL54) gene showed reasonable sensitivity and no mismatches with clinical isolates. These three pairs were further tested with clinical samples, which indicated that the two primer sets from UL55 and UL54 were the most sensitive. Interestingly, the analytical sensitivity of the PCR was inversely correlated with the size of the PCR product. In conclusion, these two primer pairs are recommended for a standardized, highly sensitive, real-time PCR.

Levels of CMV specific CD4 T cells are dynamic and correlate with CMV viremia after allogeneic stem cell transplantation

Cytomegalovirus (CMV) infection is the most frequent viral complication in patients after allogeneic stem cell transplantation. As CMV replication is tightly controlled by the cellular arm of specific immunity, the kinetics of CMV-specific T cells in association with individual reactivation episodes were prospectively analyzed in 40 allogeneic transplant recipients in a routine clinical setting and evaluated as determinant of impaired CMV control. Antigen-specific CD4 and CD8 T cells were quantified directly from whole blood using intracellular cytokine staining after specific stimulation and MHC class I multimers, respectively. Highly dynamic intraindividual changes of CMV-specific CD4 T cells were observed in patients experiencing CMV viremia. Episodes of CMV reactivation were associated with a drop of CMV-specific CD4 T cells that re-increased after viral clearance (p<0.0001). Furthermore, levels of CMV-specific CD4 T cells at the onset of viremia inversely correlated with peak viral load thereafter (p = 0.02). In contrast, CMV-peptide specific CD8 T cells did not show any association with viremia (p = 0.82). Interestingly, therapeutic dosages of cyclosporine A and corticosteroids led to a dose-dependent reduction of CMV-specific T-cell functions, indicating a causal link between intensified immunosuppressive treatment and CMV reactivation. In conclusion, levels of CMV-specific CD4 T cells inversely correlate with reactivation episodes and may represent a valuable measure to individually guide antiviral therapy after stem cell transplantation.