Impact of the COVID-19 pandemic on training conditions and education in oncologic disciplines: a survey-based analysis

PURPOSE

The COVID-19 pandemic has led to changes in global health care. Medical societies had to update guidelines and enhance new services such as video consultations. Cancer treatment had to be modified. The aim of this study is to ensure optimal care for cancer patients with the help of high-quality training even in times of crisis. We therefore conducted a nationwide survey of physicians in training in oncological disciplines during the pandemic to assess the impact on their education.

METHODS

The survey was sent to tumour centres, hospitals, specialist societies, and working and junior research groups and distributed via newsletters and homepages. Interim results and a call for participation were published as a poster (DEGRO) [26] and in the German Cancer Society (DKG) journal FORUM [42]. The survey contained 53 questions on conditions of education and training and on clinical and scientific work. Statistics were carried out with LimeSurvey and SPSS (IBM Corp., Armonk, NY, USA).

RESULTS

Between February and November 2022, 450 participants answered the survey, with radio-oncologists being the largest group (28%). Most colleagues (63%) had access to digital training methods. Virtual sessions were rated as a good alternative, especially as multidisciplinary meetings (54%) as well as in-house and external training programs (48%, 47%). The time spent by training supervisors on education was rated as less than before the pandemic by 57%. Half of all participants perceived communication (54%), motivation (44%) and atmosphere (50%) in the team as bad. The participants felt strongly burdened by extra work (55%) and by a changed team atmosphere (49%). One third felt a change in the quality of training during the pandemic and rated it as negative (35%). According to 37% of the participants, this had little influence on their own quality of work. Additional subgroup analyses revealed significant differences in gender, specialty and education level.

CONCLUSION

In order to improve oncology training in times of crisis, access to digital training options and meetings should be ensured. Participants wish for regular team meetings in person to enable good team spirit, compensation for overtime work and sufficient time for training supervisors for discussion and feedback.

Duration of protection from pneumonia after pneumococcal vaccination in haemodialysis patients - Protocol of the DOPPIO Study (Preprint)

BACKGROUND

Pneumonia is a leading cause of death in patients with end-stage chronic kidney disease treated with dialysis. Current vaccination schedules recommend pneumococcal vaccination. However, this schedule disregards findings of rapid titer decline in adult hemodialysis patients after 12 months.

OBJECTIVE

The primary objective is to compare pneumonia rates between recently vaccinated patients and patients vaccinated more than 2 years ago. As an exploratory objective, antipneumococcal antibody titers in hemodialysis patients will be determined as a function. Factors influencing antibody kinetics will be identified.

METHODS

Within this prospective multicenter study, we aim to compare 2 strata of vaccinated patients: those recently vaccinated and those vaccinated more than 2 years ago. A total of 792 patients will be enrolled. Twelve partner sites (within the German Centre for Infection Research [DZIF]) with allocated dialysis practices participate in this study. All dialysis patients who are vaccinated against pneumococcal infection in accordance with Robert Koch Institute guidelines prior to enrollment will be eligible. Data on baseline demographics, vaccination history, and underlying disease will be assessed. Pneumococcal antibody titers will be determined at baseline and every 3 months for 2 years. DZIF clinical trial units coordinate titer assessment schedules and actively follow-up on study patients for 2-5 years after enrollment, including validation of end points of hospitalization, pneumonia, and death.

RESULTS

The study has enrolled 792 patients and the last follow-up has been completed. Currently, the statistical and laboratory analyses are ongoing.

CONCLUSIONS

Results will increase physician adherence to current recommendations. Establishing a framework for the efficient evaluation of guideline recommendations through a combination of routine and study data will inform the evidence base for future guidelines.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03350425; https://clinicaltrials.gov/ct2/show/NCT03350425.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/45712.

Immunity after COVID-19 vaccination in people with higher risk of compromised immune status: a scoping review

BACKGROUND

High efficacy in terms of protection from severe COVID-19 has been demonstrated for several SARS-CoV-2 vaccines. However, patients with compromised immune status develop a weaker and less stable immune response to vaccination. Strong immune response may not always translate into clinical benefit, therefore it is important to synthesise evidence on modified schemes and types of vaccination in these population subgroups for guiding health decisions. As the literature on COVID-19 vaccines continues to expand, we aimed to scope the literature on multiple subgroups to subsequently decide on the most relevant research questions to be answered by systematic reviews.

OBJECTIVES

To provide an overview of the availability of existing literature on immune response and long-term clinical outcomes after COVID-19 vaccination, and to map this evidence according to the examined populations, specific vaccines, immunity parameters, and their way of determining relevant long-term outcomes and the availability of mapping between immune reactivity and relevant outcomes.

SEARCH METHODS

We searched the Cochrane COVID-19 Study Register, the Web of Science Core Collection, and the World Health Organization COVID-19 Global literature on coronavirus disease on 6 December 2021.  SELECTION CRITERIA: We included studies that published results on immunity outcomes after vaccination with BNT162b2, mRNA-1273, AZD1222, Ad26.COV2.S, Sputnik V or Sputnik Light, BBIBP-CorV, or CoronaVac on predefined vulnerable subgroups such as people with malignancies, transplant recipients, people undergoing renal replacement therapy, and people with immune disorders, as well as pregnant and breastfeeding women, and children. We included studies if they had at least 100 participants (not considering healthy control groups); we excluded case studies and case series.

DATA COLLECTION AND ANALYSIS

We extracted data independently and in duplicate onto an online data extraction form. Data were represented as tables and as online maps to show the frequency of studies for each item. We mapped the data according to study design, country of participant origin, patient comorbidity subgroup, intervention, outcome domains (clinical, safety, immunogenicity), and outcomes.  MAIN RESULTS: Out of 25,452 identified records, 318 studies with a total of more than 5 million participants met our eligibility criteria and were included in the review. Participants were recruited mainly from high-income countries between January 2020 and 31 October 2021 (282/318); the majority of studies included adult participants (297/318).  Haematological malignancies were the most commonly examined comorbidity group (N = 54), followed by solid tumours (N = 47), dialysis (N = 48), kidney transplant (N = 43), and rheumatic diseases (N = 28, 17, and 15 for mixed diseases, multiple sclerosis, and inflammatory bowel disease, respectively). Thirty-one studies included pregnant or breastfeeding women. The most commonly administered vaccine was BNT162b2 (N = 283), followed by mRNA-1273 (N = 153), AZD1222 (N = 66), Ad26.COV2.S (N = 42), BBIBP-CorV (N = 15), CoronaVac (N = 14), and Sputnik V (N = 5; no studies were identified for Sputnik Light). Most studies reported outcomes after regular vaccination scheme.  The majority of studies focused on immunogenicity outcomes, especially seroconversion based on binding antibody measurements and immunoglobulin G (IgG) titres (N = 179 and 175, respectively). Adverse events and serious adverse events were reported in 126 and 54 studies, whilst SARS-CoV-2 infection irrespective of severity was reported in 80 studies. Mortality due to SARS-CoV-2 infection was reported in 36 studies. Please refer to our evidence gap maps for more detailed information.

AUTHORS' CONCLUSIONS

Up to 6 December 2021, the majority of studies examined data on mRNA vaccines administered as standard vaccination schemes (two doses approximately four to eight weeks apart) that report on immunogenicity parameters or adverse events. Clinical outcomes were less commonly reported, and if so, were often reported as a secondary outcome observed in seroconversion or immunoglobulin titre studies. As informed by this scoping review, two effectiveness reviews (on haematological malignancies and kidney transplant recipients) are currently being conducted.

Anti-infective vaccination strategies in patients with hematologic malignancies or solid tumors-Guideline of the Infectious Diseases Working Party (AGIHO) of the German Society for Hematology and Medical Oncology (DGHO)

Infectious complications are a significant cause of morbidity and mortality in patients with malignancies specifically when receiving anticancer treatments. Prevention of infection through vaccines is an important aspect of clinical care of cancer patients. Immunocompromising effects of the underlying disease as well as of antineoplastic therapies need to be considered when devising vaccination strategies. This guideline provides clinical recommendations on vaccine use in cancer patients including autologous stem cell transplant recipients, while allogeneic stem cell transplantation is subject of a separate guideline. The document was prepared by the Infectious Diseases Working Party (AGIHO) of the German Society for Hematology and Medical Oncology (DGHO) by reviewing currently available data and applying evidence-based medicine criteria.

1236. Staphylococcus aureus Surgical Site Infection: Epidemiology in Europe (SALT)

Background

We conduct a retrospective, multinational cohort study with a nested case–control (NCT03353532). Data from all patients undergoing any surgical procedure in 2016 are collected within the cohort, comprising more than 150,000 procedures. S. aureus SSI cases are documented in an electronic database and matched 1:1 to controls within each center. Criteria for matching include epidemiological data and type of procedure. Participating sites are 14 major surgical centers in France, Germany, Italy, Spain, and the UK. We here present preliminary data from the interim analysis.

Methods

We conduct a retrospective, multinational cohort study with a nested case–control (NCT03353532). Data from all patients undergoing any surgical procedure in 2016 are collected within the cohort, comprising more than 150,000 procedures. S. aureus SSI cases are documented in an electronic database and matched 1:1 to controls within each center. Criteria for matching include epidemiological data and type of procedure. Participating sites are 14 major surgical centers in France, Germany, Italy, Spain, and the UK. We here present preliminary data from the interim analysis.

Results

We determine overall and procedure-specific incidence of S. aureus SSI. To date, 619 cases have been documented with a mean age of 59.0 years, 50,7% male and 49.3% female. Chronic cardiovascular disease (23%), diabetes (22%), and solid tumors (18%) are the most frequent comorbidities. Overall length of hospitalization is 19 days. A total of 20% SSI cases were treated at the intensive care unit, 49% were readmitted to the hospital, and 47% patients needed revision surgery.

Conclusion

The study includes all surgical procedures at participating centers allowing us to determine the incidence for all common surgical procedures aiming to better understand the risk of certain procedures. Furthermore, the study will analyze the risk composition of the surgical patient population to enable the calculation of the number of patients at risk in the overall surgical population in Europe. Predictive factors for S. aureus SSIwill be analyzed and thus allow future investigation into targeted prophylactic strategies such as S. aureus vaccines.

Disclosures

All authors: No reported disclosures.

2119. Matched-Paired Analysis of Patients Treated for Invasive Mucormycosis—Standard Treatment vs. Posaconazole New Formulations (MoveOn)

Background

Current first-line (first) antifungal treatment for invasive mucormycosis (IM) consists of liposomal amphotericin B (AMB). Salvage (SAL) treatment options are limited and often based on posaconazole oral suspension (POSsusp). However, with the approval of posaconazole new formulations (POSnew), patients could benefit from improved pharmacokinetics, safety and tolerability. Our aim was to assess the effectiveness of POSnew as first-line and SAL treatments for IM.

Methods

We performed a case-matched analysis with proven or probable IM patients from the FungiScope® Registry. 1st-POSnew and 1st-AMB+POSnew cases were matched with 1st-AMB-based treatment controls, and SAL-POSnew cases were matched with SAL-POSsusp controls. Each case was matched with up to three controls based on severity, hematological/oncological malignancy, surgery and/or renal dysfunction.

Results

Five patients receiving first-line POSnew alone, 18 receiving first-line POSnew combined with AMB, and 22 receiving salvage POSnew were identified. By day 42, favorable response was reported for 80.0% (n = 4/5) of patients receiving first-line POSnew, for 27.8% (n = 5/18) receiving first-line POSnew plus AMB, and for 50.0% (n = 11/22) receiving salvage POSnew. Day-42 all-cause mortality of patients receiving POSnew was lower compared with mortality in their respective controls (20.0% (n = 1/5) in 1st-POSnew vs. 53.3% (n = 8/15) in 1st-AMB; 33.3% (n = 6/18) in 1st-AMB+POSnew vs. 52.0% (n = 26/50) in 1st-AMB; 0.0% (n = 0/22) in SAL-POSnew vs. 4.4% (n = 2/45) in SAL-POSsusp).

Conclusion

In the observed patients, POSnew was effective in terms of treatment response and-associated mortality of IM. POSnew may be an alternative for the treatment of IM.

Disclosures

All authors: No reported disclosures.

Management of sepsis in neutropenic cancer patients: 2018 guidelines from the Infectious Diseases Working Party (AGIHO) and Intensive Care Working Party (iCHOP) of the German Society of Hematology and Medical Oncology (DGHO)

Sepsis and septic shock are major causes of mortality during chemotherapy-induced neutropenia for malignancies requiring urgent treatment. Thus, awareness of the presenting characteristics and prompt management is most important. Improved management of sepsis during neutropenia may reduce the mortality of cancer therapies. However, optimal management may differ between neutropenic and non-neutropenic patients. The aim of the current guideline is to give evidence-based recommendations for hematologists, oncologists, and intensive care physicians on how to manage adult patients with neutropenia and sepsis.

372. Attributable Mortality of Candidemia After Introduction of Echinocandins

Background

Candidemia is among the most frequent nosocomial blood stream infections and associated with considerable morbidity and mortality. Landmark case–control studies estimated an attributable mortality of 38% and 49%. After introduction of echinocandins, attributable mortality may have decreased.

Methods

In a case–control design, 100 consecutive, hospitalized patients with candidemia were enrolled at the University Hospital of Cologne. These cases had at least one blood culture positive for Candida spp. >48 hours post admission. We enrolled patients from January 2017 backwards until February 2014. Controls were patients without candidemia matched for age, sex, calendar year, duration of hospitalization, main admission diagnosis, and Patient Clinical Complexity Level. Risk factors for candidemia captured were malignancy, diabetes, infection other than candidemia, liver cirrhosis, hemodialysis, congestive heart failure, coronary artery disease, chronic lung disease, intensive care, mechanical ventilation, and presence of central lines. For each control patient, we considered the day of candidemia of its matched case to compare post diagnosis length of stay. We estimated attributable mortality until day 30 post candidemia diagnosis. We performed χ²-test for categorical and Student’s t-test for continuous variables, and defined a two-tailed P-value of <0.05 statistically significant.

Results

Cases and controls were 68% males. Median age was 62 and 63 years, and 25th and 75th percentile 55 and 74 years in both groups. Candidemia occurred a median 18 days post admission. For cases and controls, median length of stay post diagnosis was 17 and 15.5 days (P = 0.13), for those controls who died 12 and 19 days (P = 0.21), and for survivors 24 and 13 days (P = 0.006). Day 30 mortality rates were 38% and 11% for cases and controls (P = 0.03); thus attributable mortality was 27% (95% CI, 16%–28%).

Conclusion

Attributable mortality of nosocomial candidemia is still substantial, but was lower in our study when compared with literature from before introduction of echinocandins.

Disclosures

O. Cornely, Actelion, Amplyx, Arsanis, Astellas, AstraZeneca, Basilea, Bayer, Cidara, F2G, Gilead, GSK, Leeds University, Matinas, MedPace, Melinta, Merck/MSD, Miltenyi, Pfizer, Rempex, Roche, sanofi pasteur, Scynexis, Seres, Medicines Company: Research Contractor, Research grant and Research support. Allecra Therapeutics, Amplyx, Actelion, Astellas, Basilea, Cidara, Da Volterra, F2G, Gilead, IQVIA, Janssen, Matinas, Menarini, Merck/MSD, Paratek, PSI, Scynexis, Seres, Summit, Tetraphase, Vical: Consultant, Consulting fee. Astellas, Basilea, Gilead, Merck/MSD, Pfizer: Speaker’s Bureau, Speaker honorarium.

2046. FungiScope™: News on the Global Emerging Fungal Infection Registry

Background

Numbers of rare invasive fungal diseases (IFD) are rising worldwide due to increasing patient population at risk. To broaden the knowledge on epidemiology of rare IFD and eventually improving diagnosis and clinical outcome, FungiScope™, a global registry for rare IFD, has been initiated.

Methods

FungiScope™ uses web-based data capture (www.clinicalsurveys.net). Eligible are cases with proven or probable infection due to rare, non-endemic fungi. Data collected include demographics, underlying conditions, clinical presentation, diagnostics, antifungal therapy and outcome. Clinical isolates are collected for centralized identification, susceptibility testing and exchange between collaborators.

Results

To date, 728 valid cases of rare IFD from 41 countries are included in the registry: IFD due to Mucormycetes (n = 358), Fusarium spp. (n = 87), rare yeasts (n = 83), dematiaceae (n = 69), and Scedosporium spp. (n = 55) are the most frequently reported. FungiScope™ is supported by central labs in the Czech Republic, India, Russia, and Spain. Recently, FungiScope™ collaborators jointly published results on (I) invasive mucormycosis in children analyzed together with cases from the registry study Zygomyco.net, (II) disseminated fusariosis in 10 children, and (III) invasive infections due to Saprochaete and Geotrichum spp. in 23 patients.

Conclusion

The clinical relevance and by this the awareness of emerging IFD is increasing. FungiScope™ is a valuable resource used for collaborative studies on rare IFD. Operating and management of the registry requires considerable effort to ensure high data quality for comprehensive analyses, which provide insights into current clinical management of the diseases and thus, hold the potential to identify strategies for early diagnosis and effective treatment.

Disclosures

M. J. G. T. Vehreschild, Pfizer: Speaker’s Bureau, Speaker honorarium; MSD/Merck: Consultant and Speaker’s Bureau, Consulting fee and Speaker honorarium; Gilead Sciences: Research Contractor and Speaker’s Bureau, Research grant and Speaker honorarium; Organobalance: Speaker’s Bureau, Speaker honorarium; Astellas Pharma: Consultant, Research Contractor and Speaker’s Bureau, Consulting fee, Research grant and Speaker honorarium; 3M: Research Contractor, Research grant; DaVolterra: Research Contractor, Research grant; Berlin Chemie: Consultant, Consulting fee. J. Vehreschild, Merck / MSD: Consultant, Research Contractor and Speaker’s Bureau, Consulting fee, Research grant and Speaker honorarium; Gilead: Consultant, Research Contractor and Speaker’s Bureau, Consulting fee, Research grant and Speaker honorarium; Pfizer: Research Contractor and Speaker’s Bureau, Research grant and Speaker honorarium; Astellas Pharma: Consultant, Research Contractor and Speaker’s Bureau, Consulting fee, Research grant and Speaker honorarium; Basilea: Consultant, Research Contractor and Speaker’s Bureau, Consulting fee, Research grant and Speaker honorarium; Deutsches Zentrum für Infektionsforschung: Member, Research Contractor and Speaker’s Bureau, Research grant and Speaker honorarium; Uniklinik Freiburg/Kongress und Kommunikation: Speaker’s Bureau, Speaker honorarium; Akademie für Infektionsmedizin: Speaker’s Bureau, Speaker honorarium; Universität Manchester: Speaker’s Bureau, Speaker honorarium; Deutsche Gesellschaft für Infektiologie: Member and Speaker’s Bureau, Speaker honorarium; Ärztekammer Nordrhein: Speaker’s Bureau, Speaker honorarium; Uniklinik Aachen: Speaker’s Bureau, Speaker honorarium; Back Bay Strategies: Speaker’s Bureau, Speaker honorarium; Deutsche Gesellschaft für Innere Medizin: Member and Speaker’s Bureau, Speaker honorarium. O. A. Cornely, Amplyx Pharmaceuticals, Basilea Pharmaceutica, F2G, Gilead Sciences, MSD Sharp and Dohme, Scynexis Inc.: Consultant, Consulting fee; Amplyx Pharmaceuticals, Basilea Pharmaceutica, F2G, Gilead Sciences, MSD Sharp and Dohme, Scynexis Inc.: Grant Investigator, Research grant; Basilea Pharmaceutica, Gilead Sciences, MSD Sharp and Dohme, Pfizer: Speaker’s Bureau, Speaker honorarium.

403. Prognostic Factors in 260 Adults With Invasive Scedosporiosis From Literature and FungiScope™

Background

Invasive scedosporiosis (iS) and lomentosporiosis (iL) are an increasing concern due to intrinsic resistance of such pathogens to antifungal therapy. Guidelines recommend voriconazole, amphotericin B and surgery to treat scedosporiosis, irrespective of the causative species. Scedosporium spp. are often resistant to amphotericin B but susceptible to posaconazole and voriconazole, whereas Lomentospora prolificans (LoPro) is usually pan-resistant. Mortality rates rise to 90%, despite comprehensive treatment. Here, we describe the epidemiology of iS/L.

Methods

A retrospective analysis of patients with iS/iL was conducted to evaluate clinical characteristics and outcomes. Cases diagnosed from January 2000 until August 2017 were selected from the literature and the FungiScope™ registry. In vitro susceptibility to approved and new antifungals was determined according to EUCAST and CLSI methods.

Results

We identified 208 cases with infection caused by Scedosporium spp. and 56 by LoPro. iS was most frequently reported in patients after solid organ transplantation (27.9%), iL in patients with underlying malignancy (51.9%). Skin, lung, CNS, and eye were most frequently involved in iS cases, whereas involvement of lung, eye, and blood stream infection were most common in iL cases. Posaconazole and voriconazole showed good in vitro activity against most Scedosporium spp. isolates, but not LoPro. The new antifungal drug Olorofim was highly active against all isolates tested in vitro, also LoPro. All-cause mortality in Scedosporium spp. cases ranged from 12.5% in trauma patients to 55.2% in patients with malignancy, in the LoPro group from 28.6% in surgical patients to 85.2% in patients with malignancy. In iS cases worse outcome was associated with disseminated disease and CNS involvement in transplant recipients, and lung involvement in patients with malignancy. In iL cases, malignancy and fungemia were associated with worse outcome.

Conclusion

Clinical presentation and outcome vary between iS and iL cases. Blood stream infection and CNS involvement are associated with worse outcome. Activity of Olorofim against Scedosporium spp. and LoPro will be evaluated in an upcoming phase III trial.

Disclosures

J. Vehreschild, Merck / MSD: Consultant, Research Contractor and Speaker’s Bureau, Consulting fee, Research grant and Speaker honorarium. Gilead: Consultant, Research Contractor and Speaker’s Bureau, Consulting fee, Research grant and Speaker honorarium. Pfizer: Research Contractor and Speaker’s Bureau, Research grant and Speaker honorarium. Astellas Pharma: Consultant, Research Contractor and Speaker’s Bureau, Consulting fee, Research grant and Speaker honorarium. Basilea: Consultant, Research Contractor and Speaker’s Bureau, Consulting fee, Research grant and Speaker honorarium. Deutsches Zentrum für Infektionsforschung: Member, Research Contractor and Speaker’s Bureau, Research grant and Speaker honorarium Uniklinik Freiburg / Kongress und Kommunikation: Speaker’s Bureau, Speaker honorarium. Akademie für Infektionsmedizin: Speaker’s Bureau, Speaker honorarium. Universität Manchester: Speaker’s Bureau, Speaker honorarium, Deutsche Gesellschaft für Infektiologie: Member and Speaker’s Bureau, Speaker honorarium. Ärztekammer Nordrhein: Speaker’s Bureau, Speaker honorarium. Uniklinik Aachen: Speaker’s Bureau, Speaker honorarium. Back Bay Strategies: Speaker’s Bureau, Speaker honorarium. Deutsche Gesellschaft für Innere Medizin: Member and Speaker’s Bureau, Speaker honorarium. M. J. G. T. Vehreschild, Pfizer: Speaker’s Bureau, Speaker honorarium. MSD/Merck: Consultant and Speaker’s Bureau, Consulting fee and Speaker honorarium. Gilead Sciences: Research Contractor and Speaker’s Bureau, Research grant and Speaker honorarium. Organobalance: Speaker’s Bureau, Speaker honorarium Astellas Pharma: Consultant, Research Contractor and Speaker’s Bureau, Consulting fee, Research grant and Speaker honorarium. 3M: Research Contractor, Research grant. DaVolterra: Research Contractor, Research grant. Berlin Chemie: Consultant, Consulting fee

O. A. Cornely, Amplyx Pharmaceuticals, Basilea Pharmaceutica, F2G, Gilead Sciences, MSD Sharp and Dohme, Scynexis Inc.: Consultant, Consulting fee

Amplyx Pharmaceuticals, Basilea Pharmaceutica, F2G, Gilead Sciences, MSD Sharp and Dohme, Scynexis Inc.: Grant Investigator, Research grant

Basilea Pharmaceutica, Gilead Sciences, MSD Sharp and Dohme, Pfizer: Speaker’s Bureau, Speaker honorarium

Novel bi-allelic splice mutations in CARD9 causing adult-onset Candida endophthalmitis

CARD9 deficiency (CANDF2; OMIM# 212050) is an autosomal-recessive monogenic inborn error of immunity conferring susceptibility to invasive fungal diseases, including the very distinct syndrome of spontaneous central nervous system candidiasis, in which opportunistic yeast of the genus Candida infect the central nervous system (either brain parenchyma and/or meninges) in the absence of trauma, chemotherapy or underlying systemic disease. We present a patient with spontaneous endophthalmitis of the right eye due to Candida albicans; further investigations revealed concomitant cerebral abscess. She had a history of left endophthalmitis due to the dematiaceous mould, Aureobasidium pullulans, 15 years earlier. Targeted sequencing of the CARD9 gene revealed 2 novel variants (c.184G>A and c.288C>T). Analysis in silico predicted each variant altered splicing, which was confirmed by sequencing of cDNA from proband and carrier offsprings: c.184G>A results in a 4-base pair frameshift deletion with loss of allelic expression; c.288C>T results in an in-frame 36-bp pair deletion with detectable protein. CARD9 deficiency can present with a phenotype of spontaneous candidal endophthalmitis. We report 2 novel mutations in CARD9, both affecting splicing, expanding the range of morbid variants causing CARD9 deficiency, emphasising the importance of both genomic and cDNA sequencing for this condition.

Abstract 3980: The immunomodulatory agent L-MTP-PE induces activation and expansion of human γδ T cells capable of lysing osteosarcoma cells

The outcome of patients with metastatic osteosarcoma remains poor despite aggressive multimodality therapy. Liposomal Muramyl Tripeptide Phosphatidyl Ethanolamine (L-MTP-PE) is a non-specific immune modulator that activates monocytes and macrophages and has shown antitumor activity in osteosarcoma. The mechanism of action of L-MTP-PE remains unresolved. Here we investigated the effects of the agent on lymphocyte subpopulations.

Whole peripheral blood from 9 healthy donors were stimulated with L-MTP-PE for 24 hours. Compared to non-stimulated controls, a proliferative response of CD3+ lymphocytes was found (1.77±0.06 fold expansion, p=&lt;0.001). The strongest effect was observed on the γδ TCR+ CD3+ T cell subpopulation which expanded 5.0±1.0 fold. To further evaluate the effects of L-MTP-PE on γδ T cell proliferation, mononuclear cells were isolated from peripheral blood of 5 healthy donors and cultured in the presence of L-MTP-PE. On day 11, γδ T cells had expanded 4.6±0.6 fold compared to medium-controls. Addition of interleukin-2 (IL-2) to the cultures increased expansion of γδ T cells up to 9.8±1.6. In comparison, the known γδ T-cell stimulatory aminobisphosphonate agent zoledronic acid (ZA) combined with IL-2 induced 25.8±7.2-fold expansion. γδ T cell stimulation by ZA was previously shown to involve inhibition of the mevalonate pathway enzyme farnesyl diphosphate synthase and subsequent increase of isopentyl pyrophosphate levels. To explore the mechanism of γδ T cell expansion by L-MTP-PE, coincubation experiments were repeated in the presence of the HMG-CoA reductase inhibitor mevastatin. Addition of mevastatin resulted in a 5.1±1.8-fold reduction of L-MTP-PE induced γδ T cell expansion, confirming a critical role of the mevalonate pathway in γδ T cell expansion and thus a mechanism comparable to ZA. To explore the in vitro antitumor activity of L-MTP-PE activated γδ T cells, 24 hour coincubation experiments were performed with the osteosarcoma cell lines HOS and SAOS on day 6 of cultures. In a flow-cytometry based cytotoxicity assay, substantial cytolysis of osteosarcoma cells from both cell lines was observed after coincubation with both L-MTP-PE- and L-MTP-PE/IL-2-stimulated γδ T cells. At an effector-to-target-ratio of 1:1, L-MTP-PE-stimulated γδ T cells reduced viable cell counts of HOS and SAOS to 41.4±2.7% and 54.0±7.6%, respectively, and L-MTP-PE/IL-2-stimulated γδ T cells decreased cell counts to 33.7±2.0% and 23.0±0.9%. In comparison, ZA/IL-2-stimulated γδ T cells resulted in reduced viability to 46.2±1.0% (HOS) and 38.9±3.8% (SAOS).

We conclude that L-MTP-PE induces effective in vitro expansion of γδ T cells via a mechanisms involving the mevalonate pathway, in a manner similar to aminobisphosphonate agents. L-MTP-PE-activated γδ T cells have the potential to lyse osteosarcoma cells and may thus be involved in the antitumor effects of this agents.

Citation Format: Sibylle Mellinghoff, Bianca Altvater, Uta Dirksen, Heribert Juergens, Claudia Rossig, Martina Ahlmann. The immunomodulatory agent L-MTP-PE induces activation and expansion of human γδ T cells capable of lysing osteosarcoma cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3980. doi:10.1158/1538-7445.AM2013-3980