Costs and resource utilization patterns in surgical site infections: a pre-COVID-19 perspective from France, Germany, Spain, and the UK

BACKGROUND

Surgical site infections (SSIs), mainly caused by Staphylococcus aureus, pose a significant economic burden in Europe, leading to increased hospitalization duration, mortality, and treatment costs, particularly with drug-resistant strains such as meticillin-resistant S. aureus.

AIM

To conduct a case-control study on the economic impact of S. aureus SSI in adult surgical patients across high-volume centres in France, Germany, Spain, and the UK, aiming to assess the overall and procedure-specific burden across Europe.

METHODS

The SALT study is a multinational, retrospective cohort study with a nested case-control analysis focused on S. aureus SSI in Europe. The study included participants from France, Germany, Italy, Spain, and the UK who underwent invasive surgery in 2016 and employed a micro-costing approach to evaluate health economic factors, matching S. aureus SSI cases with controls.

FINDINGS

In 2016, among 178,904 surgical patients in five European countries, 764 developed S. aureus SSI. Matching 744 cases to controls, the study revealed that S. aureus SSI cases incurred higher immediate hospitalization costs (€8,810), compared to controls (€6,032). Additionally, S. aureus SSI cases exhibited increased costs for readmissions within the first year post surgery (€7,961.6 versus €5,298.6), with significant differences observed. Factors associated with increased surgery-related costs included the cost of hospitalization immediately after surgery, first intensive care unit (ICU) admission within 12 months, and hospital readmission within 12 months, as identified through multivariable analysis.

CONCLUSION

The higher rates of hospitalization, ICU admissions, and readmissions among S. aureus SSI cases highlight the severity of these infections and their impact on healthcare costs, emphasizing the potential benefits of evidence-based infection control measures and improved patient care to mitigate the economic burden.

Individual and institutional predisposing factors of MRSA surgical site infection and outcomes-a retrospective case-control-study in 14 European high-volume surgical centres

Objectives

To assess incidence rates of surgical site infections (SSI) by MRSA and to determine related factors and clinical outcome compared to MSSA, including country-specific, institutional and patient determinants.

Patients and methods

We performed a subgroup analysis of the Europe-wide SALT (NCT03353532) study population with MRSA SSI from 14 centres in France, Germany, Italy, Spain and the UK.

Results

An overall MRSA SSI incidence of 0.06% (n = 104) was found in 178 903 patients undergoing invasive surgery in 2016. Frequently observed comorbidities were chronic cardiovascular disease, diabetes and solid tumours. Compared to the overall MRSA SSI incidence, incidence rates were significantly higher in Spain (58 of 67 934 cases) and lower in Germany (16 of 46 443 cases; both P < 0.05). Centres with antibiotic stewardship (ABS) and infectious disease (ID) consultation programmes (n = 3/14) had lower MRSA rates (17 of 43 556 cases versus 61 of 83 048 cases, P < 0.05). In bivariate analyses, MRSA SSI patients were significantly older, had higher BMI and more comorbidities compared to MSSA (P < 0.05 each). Surgery performed between 6:00 and 12:00 pm led to higher MRSA proportions among S. aureus SSI (17 of 104 cases versus 62 of 640 cases, P < 0.05).

Conclusions

This study shows low overall and country-specific incidence rates of MRSA SSI in Europe. We could show significant differences between countries as well as between centres with established ABS and ID consultation programmes were observed. The number of those programmes seems too small against this background.

Detection of sub-nmol amounts of the antiviral drug favipiravir in 19F MRI using photo-chemically induced dynamic nuclear polarization

In biological tissues, 19F magnetic resonance (MR) enables the non-invasive, background-free detection of 19F-containing biomarkers. However, the signal-to-noise ratio (SNR) is usually low because biomarkers are typically present at low concentrations. Measurements at low magnetic fields further reduce the SNR. In a proof-of-principal study we applied LED-based photo-chemically induced dynamic nuclear polarization (photo-CIDNP) to amplify the 19F signal at 0.6 T. For the first time, 19F MR imaging (MRI) and spectroscopy (MRS) of a fully biocompatible model system containing the antiviral drug favipiravir has been successfully performed. This fluorinated drug has been used to treat Ebola and COVID-19. Since the partially cyclic reaction scheme for photo-CIDNP allows for multiple data acquisitions, averaging further improved the SNR. The mean signal gain factor for 19F has been estimated to be in the order of 103. An in-plane resolution of 0.39 × 0.39 mm2 enabled the analysis of spatially varying degrees of hyperpolarization. The minimal detectable amount of favipiravir per voxel was estimated to about 500 pmol. The results show that 19F photo-CIDNP is a promising method for the non-invasive detection of suitable 19F-containing drugs and other compounds with very low levels of the substance.

Oncological outcomes of standard versus prolonged time to surgery after neoadjuvant chemoradiotherapy for oesophageal cancer in the multicentre, randomised, controlled NeoRes II trial

BACKGROUND

The optimal time to surgery (TTS) after neoadjuvant chemoradiotherapy (nCRT) for oesophageal cancer is unknown and has traditionally been 4-6 weeks in clinical practice. Observational studies have suggested better outcomes, especially in terms of histological response, after prolonged delay of up to 3 months after nCRT. The NeoRes II trial is the first randomised trial to compare standard to prolonged TTS after nCRT for oesophageal cancer.

PATIENTS AND METHODS

Patients with resectable, locally advanced oesophageal cancer were randomly assigned to standard delay of surgery of 4-6 weeks or prolonged delay of 10-12 weeks after nCRT. The primary endpoint was complete histological response of the primary tumour in patients with adenocarcinoma (AC). Secondary endpoints included histological tumour response, resection margins, overall and progression-free survival in all patients and stratified by histologic type.

RESULTS

Between February 2015 and March 2019, 249 patients from 10 participating centres in Sweden, Norway and Germany were randomised: 125 to standard and 124 to prolonged TTS. There was no significant difference in complete histological response between AC patients allocated to standard (21%) compared to prolonged (26%) TTS (P = 0.429). Tumour regression, resection margins and number of resected lymph nodes, total and metastatic, did not differ between the allocated interventions. The first quartile overall survival in patients allocated to standard TTS was 26.5 months compared to 14.2 months after prolonged TTS (P = 0.003) and the overall risk of death during follow-up was 35% higher after prolonged delay (hazard ratio 1.35, 95% confidence interval 0.94-1.95, P = 0.107).

CONCLUSION

Prolonged TTS did not improve histological complete response or other pathological endpoints, while there was a strong trend towards worse survival, suggesting caution in routinely delaying surgery for >6 weeks after nCRT.

Staphylococcus aureus surgical site infection rates in 5 European countries

OBJECTIVE

To determine the overall and procedure-specific incidence of surgical site infections (SSI) caused by Staphylococcus aureus (S. aureus) as well as risk factors for such across all surgical disciplines in Europe.

METHODS

This is a retrospective cohort of patients with surgical procedures performed at 14 European centres in 2016, with a nested case-control analysis. S. aureus SSI were identified by a semi-automated crossmatching bacteriological and electronic health record data. Within each surgical procedure, cases and controls were matched using optimal propensity score matching.

RESULTS

A total of 764 of 178 902 patients had S. aureus SSI (0.4%), with 86.0% of these caused by methicillin susceptible and 14% by resistant pathogens. Mean S. aureus SSI incidence was similar for all surgical specialties, while varying by procedure.

CONCLUSIONS

This large procedure-independent study of S. aureus SSI proves a low overall infection rate of 0.4% in this cohort. It provides proof of principle for a semi-automated approach to utilize big data in epidemiological studies of healthcare-associated infections. Trials registration The study was registered at clinicaltrials.gov under NCT03353532 (11/2017).

TEsoNet: knowledge transfer in surgical phase recognition from laparoscopic sleeve gastrectomy to the laparoscopic part of Ivor-Lewis esophagectomy

BACKGROUND

Surgical phase recognition using computer vision presents an essential requirement for artificial intelligence-assisted analysis of surgical workflow. Its performance is heavily dependent on large amounts of annotated video data, which remain a limited resource, especially concerning highly specialized procedures. Knowledge transfer from common to more complex procedures can promote data efficiency. Phase recognition models trained on large, readily available datasets may be extrapolated and transferred to smaller datasets of different procedures to improve generalizability. The conditions under which transfer learning is appropriate and feasible remain to be established.

METHODS

We defined ten operative phases for the laparoscopic part of Ivor-Lewis Esophagectomy through expert consensus. A dataset of 40 videos was annotated accordingly. The knowledge transfer capability of an established model architecture for phase recognition (CNN + LSTM) was adapted to generate a "Transferal Esophagectomy Network" (TEsoNet) for co-training and transfer learning from laparoscopic Sleeve Gastrectomy to the laparoscopic part of Ivor-Lewis Esophagectomy, exploring different training set compositions and training weights.

RESULTS

The explored model architecture is capable of accurate phase detection in complex procedures, such as Esophagectomy, even with low quantities of training data. Knowledge transfer between two upper gastrointestinal procedures is feasible and achieves reasonable accuracy with respect to operative phases with high procedural overlap.

CONCLUSION

Robust phase recognition models can achieve reasonable yet phase-specific accuracy through transfer learning and co-training between two related procedures, even when exposed to small amounts of training data of the target procedure. Further exploration is required to determine appropriate data amounts, key characteristics of the training procedure and temporal annotation methods required for successful transferal phase recognition. Transfer learning across different procedures addressing small datasets may increase data efficiency. Finally, to enable the surgical application of AI for intraoperative risk mitigation, coverage of rare, specialized procedures needs to be explored.

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.

Perioperative or only adjuvant gemcitabine plus nab-paclitaxel for resectable pancreatic cancer (NEONAX)-a randomized phase II trial of the AIO pancreatic cancer group

BACKGROUND

Data on perioperative chemotherapy in resectable pancreatic ductal adenocarcinoma (rPDAC) are limited. NEONAX examined perioperative or adjuvant chemotherapy with gemcitabine plus nab-paclitaxel in rPDAC (National Comprehensive Cancer Network criteria).

PATIENTS AND METHODS

NEONAX is a prospective, randomized phase II trial with two independent experimental arms. One hundred twenty-seven rPDAC patients in 22 German centers were randomized 1 : 1 to perioperative (two pre-operative and four post-operative cycles, arm A) or adjuvant (six cycles, arm B) gemcitabine (1000 mg/m2) and nab-paclitaxel (125 mg/m2) on days 1, 8 and 15 of a 28-day cycle.

RESULTS

The primary endpoint was disease-free survival (DFS) at 18 months in the modified intention-to-treat (ITT) population [R0/R1-resected patients who started neoadjuvant chemotherapy (CTX) (A) or adjuvant CTX (B)]. The pre-defined DFS rate of 55% at 18 months was not reached in both arms [A: 33.3% (95% confidence interval [CI] 18.5% to 48.1%), B: 41.4% (95% CI 20.7% to 62.0%)]. Ninety percent of patients in arm A completed neoadjuvant treatment, and 42% of patients in arm B started adjuvant chemotherapy. R0 resection rate was 88% (arm A) and 67% (arm B), respectively. Median overall survival (mOS) (ITT population) as a secondary endpoint was 25.5 months (95% CI 19.7-29.7 months) in arm A and 16.7 months (95% CI 11.6-22.2 months) in the upfront surgery arm. This difference corresponds to a median DFS (mDFS) (ITT) of 11.5 months (95% CI 8.8-14.5 months) in arm A and 5.9 months (95% CI 3.6-11.5 months) in arm B. Treatment was safe and well tolerable in both arms.

CONCLUSIONS

The primary endpoint, DFS rate of 55% at 18 months (mITT population), was not reached in either arm of the trial and numerically favored the upfront surgery arm B. mOS (ITT population), a secondary endpoint, numerically favored the neoadjuvant arm A [25.5 months (95% CI 19.7-29.7months); arm B 16.7 months (95% CI 11.6-22.2 months)]. There was a difference in chemotherapy exposure with 90% of patients in arm A completing pre-operative chemotherapy and 58% of patients starting adjuvant chemotherapy in arm B. Neoadjuvant/perioperative treatment is a novel option for patients with resectable PDAC. However, the optimal treatment regimen has yet to be defined. The trial is registered with ClinicalTrials.gov (NCT02047513) and the European Clinical Trials Database (EudraCT 2013-005559-34).

Harmonized procedure coding system for surgical procedures and analysis of surgical site infections (SSI) of five European countries

BACKGROUND

The use of routine data will be essential in future healthcare research. Therefore, harmonizing procedure codes is a first step to facilitate this approach as international research endeavour. An example for the use of routine data on a large scope is the investigation of surgical site infections (SSI). Ongoing surveillance programs evaluate the incidence of SSI on a national or regional basis in a limited number of procedures. For example, analyses by the European Centre for Disease Prevention (ECDC) nine procedures and provides a mapping table for two coding systems (ICD9, National Healthcare Safety Network [NHSN]). However, indicator procedures do not reliably depict overall SSI epidemiology. Thus, a broader analysis of all surgical procedures is desirable. The need for manual translation of country specific procedures codes, however, impedes the use of routine data for such an analysis on an international level. This project aimed to create an international surgical procedure coding systems allowing for automatic translation and categorization of procedures documented in country-specific codes.

METHODS

We included the existing surgical procedure coding systems of five European countries (France, Germany, Italy, Spain, and the United Kingdom [UK]). In an iterative process, country specific codes were grouped in ever more categories until each group represented a coherent unit based on method of surgery, interventions performed, extent and site of the surgical procedure. Next two ID specialist (arbitrated by a third in case of disagreement) independently assigned country-specific codes to the resulting categories. Finally, specialist from each surgical discipline reviewed these assignments for their respective field.

RESULTS

A total number of 153 SALT (Staphylococcus aureus Surgical Site Infection Multinational Epidemiology in Europe) codes from 10 specialties were assigned to 15,432 surgical procedures. Almost 4000 (26%) procedure codes from the SALT coding system were classified as orthopaedic and trauma surgeries, thus this medical field represents the most diverse group within the SALT coding system, followed by abdominal surgical procedures with 2390 (15%) procedure codes.

CONCLUSION

Mapping country-specific codes procedure codes onto to a limited number of coherent, internally and externally validated codes proofed feasible. The resultant SALT procedure code gives the opportunity to harmonize big data sets containing surgical procedures from international centres, and may simplify comparability of future international trial findings.

TRIAL REGISTRATION

The study was registered at clinicaltrials.gov under NCT03353532 on November 27^th, 2017.

Improved Tissue Processing in Esophageal Adenocarcinoma After Ivor Lewis Esophagectomy Allows Histological Analysis of All Surgically Removed Lymph Nodes with Significant Effects on Nodal UICC Stages

BACKGROUND

In esophageal carcinoma, the numbers of metastatic and total removed lymph nodes (LN) are well-established variables of long-term prognosis. The overall rate of retrieved LN depends on neoadjuvant treatment, the extent of surgical lymphadenectomy, and the modality of the pathological workup. The question in this study is whether technically extended histopathological preparation can increase the number of detected (metastatic) LN with an impact on nodal UICC staging.

PATIENTS AND METHODS

A cohort of 77 patients with esophageal adenocarcinoma was treated with Ivor Lewis esophagectomy including standardized two-field lymphadenectomy. The specimens were grossed, and all manually detectable LN were retrieved. The remaining tissue was completely embedded by the advanced "acetone compression" retrieval technique. The primary outcome parameter was the total number of detected lymph nodes before and after acetone workup.

RESULTS

A mean number of 23,1 LN was diagnosed after standard manual LN preparation. With complete embedding of the fatty tissue using acetone compression, the number increased to 40.5 lymph nodes (p < 0.0001). The mean number of metastatic LN increased from 3.2 to 4.2 nodal metastases following acetone compression (p < 0.0001). Additional LN metastases which caused a change in the primary (y)pN stage were found in ten patients (13.0%).

CONCLUSIONS

Advanced lymph node retrieval by acetone compression allows a reliable statement on the real number of removed LN. Results demonstrate an impact on the nodal UICC stage. A future multicenter study will examine the prognostic impact of improved lymph node retrieval on long-term oncologic outcome.

Baseline Chest Computed Tomography as Standard of Care in High-Risk Hematology Patients

Baseline chest computed tomography (BCT) in high-risk hematology patients allows for the early diagnosis of invasive pulmonary aspergillosis (IPA). The distribution of BCT implementation in hematology departments and impact on outcome is unknown. A web-based questionnaire was designed. International scientific bodies were invited. The estimated numbers of annually treated hematology patients, chest imaging timepoints and techniques, IPA rates, and follow-up imaging were assessed. In total, 142 physicians from 43 countries participated. The specialties included infectious diseases (n = 69; 49%), hematology (n = 68; 48%), and others (n = 41; 29%). BCT was performed in 57% (n = 54) of 92 hospitals. Upon the diagnosis of malignancy or admission, 48% and 24% performed BCT, respectively, and X-ray was performed in 48% and 69%, respectively. BCT was more often used in hematopoietic cell transplantation and in relapsed acute leukemia. European centers performed BCT in 59% and non-European centers in 53%. Median estimated IPA rate was 8% and did not differ between BCT (9%; IQR 5–15%) and non-BCT centers (7%; IQR 5–10%) (p = 0.69). Follow-up computed tomography (CT) for IPA was performed in 98% (n = 90) of centers. In high-risk hematology patients, baseline CT is becoming a standard-of-care. Chest X-ray, while inferior, is still widely used. Randomized, controlled trials are needed to investigate the impact of BCT on patient outcome.

Phosphatidylinositol 3,4-bisphosphate synthesis and turnover are spatially segregated in the endocytic pathway

Phosphoinositides play crucial roles in intracellular membrane dynamics and cell signaling, with phosphatidylinositol (PI) 3-phosphates being the predominant phosphoinositide lipids at endosomes and lysosomes, whereas PI 4-phosphates, such as phosphatidylinositol 4,5-bisphosphate (PI(4,5)P₂), are enriched at the cell surface including sites of endocytosis. How PI 4-phosphates and PI 3-phosphates are dynamically interconverted within the endocytic pathway and how this is controlled in space and time remains poorly understood. Here, combining live imaging, genome engineering, and acute chemical and genetic manipulations, we found that local synthesis of PI(3,4)P₂ by phosphatidylinositol 3-kinase C2α at plasma membrane clathrin-coated pits is spatially segregated from its hydrolysis by the PI(3,4)P₂-specific inositol polyphosphate 4-phosphatase 4A (INPP4A). We observed that INPP4A is dispensable for clathrin-mediated endocytosis and is undetectable in endocytic clathrin-coated pits. Instead, we found that INPP4A partially localizes to endosomes and that loss of INPP4A in HAP1 cancer cells perturbs signaling via AKT kinase and mTOR complex 1. These results reveal a function for INPP4-mediated PI(3,4)P₂ hydrolysis in local regulation of growth factor and nutrient signals at endosomes in cancer cells. They further suggest a model whereby synthesis and turnover of PI(3,4)P₂ are spatially segregated within the endocytic pathway to couple endocytic membrane traffic to growth factor and nutrient signaling.

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.

Diagnostic criteria and symptom grading for delayed gastric conduit emptying after esophagectomy for cancer: international expert consensus based on a modified Delphi process

Delayed gastric conduit emptying (DGCE) after esophagectomy for cancer is associated with adverse outcomes and troubling symptoms. Widely accepted diagnostic criteria and a symptom grading tool for DGCE are missing. This hampers the interpretation and comparison of studies. A modified Delphi process, using repeated web-based questionnaires, combined with live interim group discussions was conducted by 33 experts within the field, from Europe, North America, and Asia. DGCE was divided into early DGCE if present within 14 days of surgery and late if present later than 14 days after surgery. The final criteria for early DGCE, accepted by 25 of 27 (93%) experts, were as follows: >500 mL diurnal nasogastric tube output measured on the morning of postoperative day 5 or later or >100% increased gastric tube width on frontal chest x-ray projection together with the presence of an air-fluid level. The final criteria for late DGCE accepted by 89% of the experts were as follows: the patient should have 'quite a bit' or 'very much' of at least two of the following symptoms; early satiety/fullness, vomiting, nausea, regurgitation or inability to meet caloric need by oral intake and delayed contrast passage on upper gastrointestinal water-soluble contrast radiogram or on timed barium swallow. A symptom grading tool for late DGCE was constructed grading each symptom as: 'not at all', 'a little', 'quite a bit', or 'very much', generating 0, 1, 2, or 3 points, respectively. For the five symptoms retained in the diagnostic criteria for late DGCE, the minimum score would be 0, and the maximum score would be 15. The final symptom grading tool for late DGCE was accepted by 27 of 31 (87%) experts. For the first time, diagnostic criteria for early and late DGCE and a symptom grading tool for late DGCE are available, based on an international expert consensus process.

Responsiveness of swine divergently selected for feed efficiency to exogenous adrenocorticotropic hormone and glucose challenges

Increasing the feed efficiency of lean tissue gains is an important goal for improving sustainable pork production and profitability for swine producers. To study feed efficiency, genetic selection based on residual feed intake (RFI) was used to create two divergent lines. Low-RFI pigs consume less feed for equal weight gain compared with their less-efficient, high-RFI counterparts. As cortisol and insulin are important energy control and growth regulators, our objective was to evaluate the role of the adrenocorticotropic hormone (ACTH)-cortisol and the glucose-insulin axes in pigs divergently selected for RFI. Adrenocorticotropic hormone (0.2 IU/kg BW)-stimulated cortisol and non-esterified fatty acids (NEFA) concentrations and intravenous glucose tolerance test (IVGTT; 0.25 g/kg BW)-stimulated glucose, insulin, and NEFA concentrations were assessed in six low-RFI and six high-RFI gilts (68 ± 5.2 kg). Before the ACTH challenge, low-RFI gilts tended to have less baseline plasma cortisol (P = 0.08) but no difference in NEFA concentrations (P = 0.63) compared with high-RFI gilts. After the ACTH challenge, low-RFI gilts had less cortisol (P = 0.04) and NEFA concentrations (P = 0.05) compared with high-RFI gilts. Glucose, insulin, and NEFA concentrations did not differ between genetic lines before the IVGTT. After glucose infusion, low-RFI gilts had greater insulin concentrations (P = 0.003) but did not differ in glucose or NEFA concentrations compared with high-RFI gilts. These results indicate that genetic selection for reduced RFI (improved feed efficiency) resulted in less stress responsiveness and an increase in insulin after glucose infusion. These data have implications for identifying and selecting more feed efficient pigs and for understanding the physiological mechanisms underlying feed efficiency.

Therapy susceptible germline-related BRCA 1-mutation in a case of metastasized mixed adeno-neuroendocrine carcinoma (MANEC) of the small bowel

Background

Adenocarcinomas or combined adeno-neuroendocrine carcinomas (MANEC) of small bowel usually have a dismal prognosis with limited systemic therapy options. This is the first description of a patient showing a germline-related BRCA1 mutated MANEC of his ileum. The tumor presented a susceptibility to a combined chemotherapy and the PARP1-inhibitor olaparib.

Case presentation

A 74-year old male patient presented with a metastasized MANEC of his ileum. Due to clinical symptoms his ileum-tumor and the single brain metastasis were removed. We verified the same pathogenic (class 5) BRCA1 mutation in different tumor locations. There was no known personal history of a previous malignant tumor. Nevertheless we identified his BRCA1 mutation as germline-related. A systemic treatment was started including Gemcitabine followed by selective internal radiotherapy (SIRT) to treat liver metastases and in the further course Capecitabine but this treatment finally failed after 9 months and all liver metastases showed progression. The treatment failure was the reason to induce an individualized therapeutic approach using combined chemotherapy of carboplatin, paclitaxel and the Poly (ADP-ribose) polymerase- (PARP)-inhibitor olaparib analogous to the treatment protocol of Oza et al.

All liver metastases demonstrated with significant tumor regression after 3 months and could be removed. In his most current follow up from December 2017 (25 months after his primary diagnosis) the patient is in a very good general condition without evidence for further metastases.

Conclusion

We present first evidence of a therapy susceptible germline-related BRCA1 mutation in small bowel adeno-neuroendocrine carcinoma (MANEC). Our findings offer a personalized treatment option. The germline background was unexpected in a 74-year old man with no previously known tumor burden. We should be aware of the familiar background in tumors of older patients as well.

Untersuchungen zum Somatostatinrezeptor-Status bei nicht-medullären Schilddrüsenkarzinomen

Ziel: In aktuellen ln-vitro- und In-vivo-Untersuchungen wurde eine Somatostatinrezeptor-Expression bei einigen nicht-medullären Schilddrüsenkarzinomen nachgewiesen. In der vorliegenden Studie wird der Somatostatinrezeptor-Status bei dieser Tumorentität in einem größeren Patientenkollektiv untersucht. Patienten und Methoden: Wir verglichen 131-lod- mit 111-ln-Pentetreotide-Szintigraphien bei 24 Patienten mit metastasiertem, nicht-medullären Schilddrüsenkarzinom. Die Befunde wurden mit anderen bildgebenden Verfahren korreliert. Zusätzlich erfolgten Rezeptor-Autoradiographien bei einem Patienten, eine Octreotide-Behandlung bei einem anderen und die Verabreichung von 90-Y- sowie 111-ln-DOTATOC bei zwei weiteren Patienten. Ergebnisse: Bei 8/15 Patienten mit papillärem oder follikulärem Schilddrüsenkarzinom erwies sich 111-ln-Pentetreotide dem 131-I als unterlegen, bei 1/15 als gleichwertig und bei 6/15 als überlegen. Bei 8/9 Patienten mit onkozytärem Schilddrüsenkarzinom zeigten die Metastasen eine 111-ln-Pentetreotide-Akkumulation unterschiedlicher Intensität, während die 131-l-Szintigraphien hier bis auf eine Ausnahme negativ waren. Im Vergleich mit 201-Tl oder 99m-Tc-Sestamibi erwies sich 111-ln-Pentetreotide als gleichwertig oder überlegen, aber im Vergleich zum 18-FFDG-PET zumeist als unterlegen. Die Befunde der 111-ln-Pentetreotide-Szintigraphie korrelierten gut mit der Rezeptor-Autoradiographie und der DOTATOC-Akkumulation, nicht dagegen mit dem Behandlungseffekt von »kaltem« Octreotide auf die Schilddrüsenkarzinom-Metastasen. Schlußfolgerungen: Diverse Metastasen papillärer und follikulärer Schilddrüsenkarzinome und die Mehrzahl der onkozytären Schilddrüsenkarzinom-Metastasen können Somatostatin-Rezeptoren exprimieren. Insbesondere beim onkozytären Schilddrüsenkarzinom beziehungsweise bei nicht verfügbarem PET erweist sich die 111-ln-Pentetreotide-Szintigraphie als vielversprechende Methode zur Metastasenlokalisation; sie könnte ferner von Nutzen sein bei der Selektion möglicher Kandidaten für eine Therapie mit ß-Strahler-markierten Somatostatinanaloga, wenn diese für die klinische Routine verfügbar sind.

[Differentiated surgical approach for adenocarcinoma of the gastroesophageal junction]

For adenocarcinoma of the gastroesophageal junction (GEJ) the classification of Siewert with its three subtypes is well established as a practical approach to surgical treatment. Transthoracic esophagectomy with gastric tube formation is generally accepted as the surgical standard for adenocarcinoma of the distal esophagus (GEJ type I). Intrathoracic esophagogastrostomy has become the most frequently used anastomotic technique (Ivor Lewis esophagectomy). Both the abdominal and thoracic part can be safely performed with a minimally invasive access. For subcardiac gastric cancer (GEJ type III) transhiatal extended gastrectomy is the resection of choice. For true cardiac carcinomas (GEJ type II) it has not yet been decided which of the abovementioned surgical procedures offers the best long-term survival. If technically possible in terms of a complete resection, transhiatal extended gastrectomy should be preferred because of a better postoperative quality of life. For GEJ type II tumors a minimally invasive approach is not recommended if the extent of resection cannot be safely determined preoperatively.

Incidental diagnosis of the tall-cell variant of the papillary microcarcinoma of the thyroid gland requires completion lymphadenectomy: case report

Papillary thyroid carcinoma is the most common neoplasm of the thyroid gland which is usually associated with a very good prognosis. The aim of this case report is to present the disease course of a rare tumor of the thyroid gland, which is worthwhile due to its extraordinary appearance and specific management. A 46-year-old patient presented with a pronounced right-sided, but bilateral, multinodular goiter, with a volume of approximately 80 mL, as assessed on ultrasonography. Surgical removal was indicated as scintigraphy showed a 4-cm cold nodule that almost completely took up the right thyroid lobe. Because of the micronodular texture of the left thyroid lobe, complete thyroidectomy was performed according to well-established guidelines. Histopathological investigation of the specimen revealed a follicular adenoma without any malignancy in the right thyroid lobe and the tall-cell variant of the papillary thyroid microcarcinoma in the left lobe, with a capsular invasion and diameter of 0.6 cm. Because this rare tumor subtype is known for its aggressive behavior, and there was capsular invasion, low-grade differentiation, and an increased risk for lymphatic metastases, completion lymphadenectomy of the central compartments was performed after an interdisciplinary board decision. On histopathology, there were 30 tumor-free lymph nodes; final TNM classification was as follows: pT3 pN0 [0/30] L0 V0 Pn0 R0). The postoperative course was uneventful, and surgery was followed by radioiodine therapy. Six months after the surgery, clinical follow-up did revealed any sign of recurrence. The tall-cell variant is a rare and aggressive subtype of the papillary thyroid carcinoma, and it is characterized by poor 5-year survival and high recurrence rate. According to our understanding and based on current literature, this disease requires an aggressive surgical treatment and a close follow-up, as recommended by the current guidelines.

Incidental diagnosis of the tall-cell variant of the papillary microcarcinoma of the thyroid gland requires completion lymphadenectomy: case report

Papillary thyroid carcinoma is the most common neoplasm of the thyroid gland which is usually associated with a very good prognosis. The aim of this case report is to present the disease course of a rare tumor of the thyroid gland, which is worthwhile due to its extraordinary appearance and specific management. A 46-year-old patient presented with a pronounced right-sided, but bilateral, multinodular goiter, with a volume of approximately 80 mL, as assessed on ultrasonography. Surgical removal was indicated as scintigraphy showed a 4-cm cold nodule that almost completely took up the right thyroid lobe. Because of the micronodular texture of the left thyroid lobe, complete thyroidectomy was performed according to well-established guidelines. Histopathological investigation of the specimen revealed a follicular adenoma without any malignancy in the right thyroid lobe and the tall-cell variant of the papillary thyroid microcarcinoma in the left lobe, with a capsular invasion and diameter of 0.6 cm. Because this rare tumor subtype is known for its aggressive behavior, and there was capsular invasion, low-grade differentiation, and an increased risk for lymphatic metastases, completion lymphadenectomy of the central compartments was performed after an interdisciplinary board decision. On histopathology, there were 30 tumor-free lymph nodes; final TNM classification was as follows: pT3 pN0 [0/30] L0 V0 Pn0 R0). The postoperative course was uneventful, and surgery was followed by radioiodine therapy. Six months after the surgery, clinical follow-up did revealed any sign of recurrence. The tall-cell variant is a rare and aggressive subtype of the papillary thyroid carcinoma, and it is characterized by poor 5-year survival and high recurrence rate. According to our understanding and based on current literature, this disease requires an aggressive surgical treatment and a close follow-up, as recommended by the current guidelines.

["STeP" ("Students Teaching Patients"): Medical Students Following up on Informed Consent Discussions. Results of a Methodological Change and Further Considerations]

Background: Literature shows an increasing number of reports on the incompleteness of informed consent discussions held by residents. Residents feel insecure and not adequately prepared for this task. This project aimed to integrate supervised informed consent discussions into the medical curriculum, working with "real" patients instead of other students or actors. Method: "STeP" ("Students Teaching Patients") is a teaching format which has been recently introduced at the University of Magdeburg. Initially, a certified physician prepares medical students for taking informed consent. Using standard questionnaires, students interview patients who have given consent, following up on what patients recall from the informed consent discussion. Afterwards the results are reported to the physician, who then checks back with the patient that there are no new or unanswered questions. In this part of the project, the original process was changed in that a group of patients was interviewed twice to evaluate whether students were able to increase patients' knowledge. Results: Although all students taking part in this study had already completed the surgery course, they were not sufficiently aware of the most relevant complications of laparoscopic cholecystectomy. Also it was difficult for informed patients to render the consequences and complications resulting from such a procedure. Randomly chosen patients recalled only one possible complication on average, although they had signed the informed consent form. Most of them could not explain the effects of a lesion of the bile duct. Although those patients who had been interviewed twice recalled more complications than those who had been interviewed only once, patients generally did not like to be interviewed twice, which caused us to discontinue this part of the project. Conclusions: Based on the analysis of the limitations of this method of repeated interviews, we now plan to perform STeP as a "student consultation" before the physician takes informed consent, with students reflecting their own consultation. Increase in knowledge and patient satisfaction will be measured postoperatively by the students. The results of this project are pending.

Pellicle formation in the malaria parasite

The intraerythrocytic developmental cycle of Plasmodium falciparum is completed with the release of up to 32 invasive daughter cells, the merozoites, into the blood stream. Before release, the final step of merozoite development is the assembly of the cortical pellicle, a multi-layered membrane structure. This unique apicomplexan feature includes the inner membrane complex (IMC) and the parasite's plasma membrane. A dynamic ring structure, referred to as the basal complex, is part of the IMC and helps to divide organelles and abscises in the maturing daughter cells. Here, we analyze the dynamics of the basal complex of P. falciparum. We report on a novel transmembrane protein of the basal complex termed BTP1, which is specific to the genus Plasmodium. It colocalizes with the known basal complex marker protein MORN1 and shows distinct dynamics as well as localization when compared to other IMC proteins during schizogony. Using a parasite plasma membrane marker cell line, we correlate dynamics of the basal complex with the acquisition of the maternal membrane. We show that plasma membrane invagination and IMC propagation are interlinked during the final steps of cell division.

A novel, blocking, Fc-silent anti-CD40 monoclonal antibody prolongs nonhuman primate renal allograft survival in the absence of B cell depletion

CD40-CD154 pathway blockade prolongs renal allograft survival in nonhuman primates (NHPs). However, antibodies targeting CD154 were associated with an increased incidence of thromboembolic complications. Antibodies targeting CD40 prolong renal allograft survival in NHPs without thromboembolic events but with accompanying B cell depletion, raising the question of the relative contribution of B cell depletion to the efficacy of anti-CD40 blockade. Here, we investigated whether fully silencing Fc effector functions of an anti-CD40 antibody can still promote graft survival. The parent anti-CD40 monoclonal antibody HCD122 prolonged allograft survival in MHC-mismatched cynomolgus monkey renal allograft transplantation (52, 22, and 24 days) with accompanying B cell depletion. Fc-silencing yielded CFZ533, an antibody incapable of B cell depletion but still able to potently inhibit CD40 pathway activation. CFZ533 prolonged allograft survival and function up to a defined protocol endpoint of 98-100 days (100, 100, 100, 98, and 76 days) in the absence of B cell depletion and preservation of good histological graft morphology. CFZ533 was well-tolerated, with no evidence of thromboembolic events or CD40 pathway activation and suppressed a gene signature associated with acute rejection. Thus, use of the Fc-silent anti-CD40 antibody CFZ533 appears to be an attractive approach for preventing solid organ transplant rejection.

[Management of perioperative complications following tumor resection in the upper gastrointestinal tract]

BACKGROUND

Surgical resection of tumors of the upper gastrointestinal (GI) tract represent complex procedures and are still associated with a relevant morbidity and mortality. A targeted preoperative risk analysis and patient selection with consideration of the nutritional status and comorbidities are important in order to reduce the perioperative complication rate.

RESULTS AND DISCUSSION

Anastomotic leaks still remain the most feared surgical complication and in addition to early recognition, immediate initiation of an appropriate therapy are essential. Conservative treatment can be considered for small and adequately drained fistulas as well as in cervical leakages. Indications for surgical reintervention are leaks that occur in the early postoperative course, fulminant defects with diffuse mediastinitis and conduit necrosis. The majority of anastomotic leaks can be successfully managed with minimally invasive endoscopic techniques, e.g. stent placement and endoluminal vacuum therapy. Delayed gastric emptying is frequently observed following esophageal resection and usually shows a satisfactory response to medicinal treatment and endoscopic interventions. The benefits of pyloroplasty in the primary intervention is still a matter of debate. Chylothorax is a rare but serious complication which should initially be managed with conservative measures.

CONCLUSIONS

For the successful management of postoperative complications following surgical resection of tumors of the upper GI tract both an interdisciplinary approach and the availability of an appropriate infrastructure with defined algorithms are of paramount importance. Therefore, a concentration of these procedures in specialized centers would be highly desirable.

[Arterial and portal venous complications after HPB surgical procedures: Interdisciplinary management]

The surgical treatment of hepatopancreatobiliary (HPB) diseases requires complex operative procedures. Within the last decades the morbidity (36-50 %) and mortality (<5 %) of these procedures could be reduced; nonetheless, postoperative complications still occur in 41.2 % of cases. Compared with hepatobiliary procedures, pancreatic surgery shows an increased rate of complications. Postoperative bleeding has a major effect on the outcome and the incidence is 6.7 % after pancreatic surgery and 3.2 % after hepatobiliary surgery. The major causes of early postoperative hemorrhage are related to technical difficulties in surgery whereas late onset postoperative hemorrhage is linked to anastomosis insufficiency, formation of fistulae or abscesses due to vascular arrosion or formation of pseudoaneurysms. In many cases, delayed hemorrhage is preceded by a self-limiting sentinel bleeding. The treatment is dependent on the point in time, location and severity of the hemorrhage. The majority of early postoperative hemorrhages require surgical treatment. Late onset hemorrhage in hemodynamically stable patients is preferably treated by radiological interventions. After interventional hemostatic therapy 8.2 % of patients require secondary procedures. In the case of hemodynamic instability or development of sepsis, a relaparotomy is necessary. The treatment concept includes surgical or interventional remediation of the underlying cause of the hemorrhage. Other causes of postoperative morbidity and mortality are arterial and portal venous stenosis and thrombosis. Following liver resection, thrombosis of the portal vein occurs in 8.5-9.1 % and in 11.6 % following pancreatic resection with vascular involvement. Interventional surgical procedures or conservative treatment are suitable therapeutic options depending on the time of diagnosis and clinical symptoms. The risk of morbidity and mortality after HPB surgery can be reduced only in close interdisciplinary cooperation, which is particularly true for vascular complications.

Remodeling of secretory compartments creates CUPS during nutrient starvation

Upon starvation, Grh1, a peripheral membrane protein located at endoplasmic reticulum (ER) exit sites and early Golgi in Saccharomyces cerevisiae under growth conditions, relocates to a compartment called compartment for unconventional protein secretion (CUPS). Here we report that CUPS lack Golgi enzymes, but contain the coat protein complex II (COPII) vesicle tethering protein Uso1 and the Golgi t-SNARE Sed5. Interestingly, CUPS biogenesis is independent of COPII- and COPI-mediated membrane transport. Pik1- and Sec7-mediated membrane export from the late Golgi is required for complete assembly of CUPS, and Vps34 is needed for their maintenance. CUPS formation is triggered by glucose, but not nitrogen starvation. Moreover, upon return to growth conditions, CUPS are absorbed into the ER, and not the vacuole. Altogether our findings indicate that CUPS are not specialized autophagosomes as suggested previously. We suggest that starvation triggers relocation of secretory and endosomal membranes, but not their enzymes, to generate CUPS to sort and secrete proteins that do not enter, or are not processed by enzymes of the ER-Golgi pathway of secretion.

Experimental analysis of the mechanical behavior of the viscoelastic porcine pancreas and preliminary case study on the human pancreas

The aim of this article is to study the mechanical properties of the pancreas. Up to now, the mechanical properties of the pancreas are not sufficiently characterized. The possibility of intraoperative mechanical testing of pathological pancreata will allow the classification of pancreatic diseases in the future. The application of mechanical parameters instead of the intraoperative frozen section analysis shortens waiting times in the operating room. This study proves the general applicability of shear rheology for the determination of the mechanical properties of pancreas and the assessment of graft quality for transplantation. Porcine and human pancreas samples were examined ex vivo and a nonlinear viscoelastic behavior was observed. Pancreas was found to be more viscous than liver but both abdominal organs showed a similar flow behavior. The shear deformation dependence of healthy human pancreas was similar to porcine pancreas. An increase in the post-mortem time led to an increase in the complex modulus for a post-mortem time up to 8.5 days. Histological investigations showed that an increased amount of collagen coincides with the stiffening of the pancreatic tissue.

[Treatment reality with respect to laparoscopic surgery of colonic cancer in Germany]

BACKGROUND

Prospective randomized studies and meta-analyses have shown that laparoscopic resection for colonic cancer is equivalent to open resection with respect to the oncological results and has short-term advantages in the early postoperative outcome. The aim of this study was to investigate whether laparoscopic colonic resection has become established as the standard in routine treatment.

METHODS

Data from the multicenter observational study "Quality assurance colonic cancer (primary tumor)" from the time period from 1 January 2009 to 21 December 2011 were evaluated with respect to the total proportion of laparoscopic colonic cancer resections and tumor localization and specifically for laparoscopic sigmoid colon cancer resections. A comparison between low and high volume clinics (< 30 versus ≥ 30 colonic cancer resections/year) was carried out.

RESULTS

Laparoscopic colonic cancer resections were carried out in 12 % versus 21.4 % of low and high volume clinics, respectively (p < 0.001) with a significant increase for low volume clinics (from 8.0 % to 15.6 %, p < 0.001) and a constant proportion in high volume clinics (from 21.7 % to 21.1 %, p = 0.905). For sigmoid colon cancer laparoscopic resection was carried out in 49.7 % versus 47.6 % (p = 0.584). Differences were found between low volume and high volume clinics in the conversion rates (17.3 % versus 6.6 %, p < 0.001), the length of the resected portion (Ø 23.6 cm versus 36.0 cm, p < 0.001) and the lymph node yield (Ø n = 15.7 versus 18.2, p = 0.008). There were no differences between the two groups of clinics regarding postoperative morbidity and mortality. The postoperative morbidity and length of stay were significantly lower for laparoscopic sigmoid resection than for conventional sigmoid resection.

CONCLUSION

The laparoscopic access route for colonic cancer resection is not the standard approach in the participating clinics. The laparoscopic access route has the highest proportion for sigmoid colon resection. The differences in the conversion rates, length of the resected portion and the number of lymph nodes investigated between the low volume and high volume clinics must be viewed critically and must be interpreted in connection with the long-term oncological results.

[Systemic therapy and hyperthermia for locally advanced soft tissue sarcoma]

Patients with high-risk soft tissue sarcomas (FNCLCC grades 2-3, > 5 cm and deep lying) are at a high risk of local recurrence or distant metastases despite optimal surgical tumor resection. Therefore, multimodal treatment should be considered for this difficult to treat patient group. Besides surgery, radiation therapy and chemotherapy, hyperthermia has become a valid, complementary treatment option within multimodal treatment concepts. Hyperthermia in this context means the selective heating of the tumor region to temperatures of 40-43 °C for 60 min by microwave radiation in addition to simultaneous chemotherapy or radiation therapy. A randomized phase III study demonstrated that the addition of hyperthermia to neoadjuvant chemotherapy improved tumor response and was associated with a minimal risk of early disease progression as compared to chemotherapy alone. The addition of hyperthermia to a multimodal treatment regimen for high-risk soft tissue sarcoma consisting of surgery, radiation therapy and chemotherapy, either in the neoadjuvant or adjuvant setting after incomplete or marginal tumor resection, significantly improved local progression-free and disease-free survival. Based on these results and due to the generally good tolerability of hyperthermia, this treatment method in combination with chemotherapy should be considered as a standard treatment option within multimodal treatment approaches for locally advanced high-risk soft tissue sarcoma.

[Significance of Mesenchymal Stem Cells in Gastrointestinal Disorders]

In this review we summarise the recent developments regarding the experimental and clinical use of mesenchymal stem cells (MSCs), focusing mainly on the treatment of gastrointestinal disorders. Next to their relevance in the field of regenerative medicine and immunology, this population of cells has also raised great expectations for possible applications in cancer therapy. While clinical trials were able to demonstrate the efficacy of MSCs in cases of inflammatory bowel disease and degenerative conditions of the liver, controversial results have been presented regarding their antineoplastic potential in gastrointestinal tumours. MSCs can differentiate into a large variety of specialised cells. They are capable of regulating both wound healing and immune responses through paracrine and endocrine signalling. Moreover, MSCs can be transfected with a great number of different therapeutic genes - considering their ability to selectively migrate towards neoplastic tissues, this feature allows for targeted therapy of solid tumours. Transfected genes can be designed so that they are expressed exclusively in the vicinity of the tumour, eventually triggering apoptosis in cancer cells. In this review, we demonstrate the natural distribution of exogenously applied MSCs in the host. Furthermore, we mention various methods of tracking MSCs in vivo and different parameters of administration that tend to influence therapeutic outcome (e.g., origin of MSCs, mode of application, or the potency of transfected genes). Finally, this review points out the hazards of MSC therapy, emphasising the risks related to their widespread clinical use.

[Tumor and transplantation]

Tumor treatment and transplantation-associated with unavoidable mandatory immunosuppression-appear to be unreconcilable opposites. The clinical reality shows, however, that transplantation in many early stage primary tumors is the most effective treatment. The essential immunosuppression after transplantation can however promote tumor recurrence. Immunosuppression also leads to a significant increased rate of de novo tumors-in all organ transplant recipients. However, not all immunosuppressant drugs have the same effect on tumors. In experimental and clinical settings, the class of mTOR inhibitors has a clear antitumoral effect and is recommended as the immunosuppression treatment of choice in patients with increased tumor risk. The purpose of this review is to provide the reader with the scientific background regarding the clinical problem of tumors and transplantation.

The selective sphingosine 1-phosphate receptor modulator BAF312 redirects lymphocyte distribution and has species-specific effects on heart rate

BACKGROUND AND PURPOSE

BAF312 is a next-generation sphingosine 1-phosphate (S1P) receptor modulator, selective for S1P₁ and S1P₅ receptors. S1P₁ receptors are essential for lymphocyte egress from lymph nodes and a drug target in immune-mediated diseases. Here, we have characterized the immunomodulatory potential of BAF312 and the S1P receptor-mediated effects on heart rate using preclinical and human data.

EXPERIMENTAL APPROACH

BAF312 was tested in a rat experimental autoimmune encephalomyelitis (EAE) model. Electrophysiological recordings of G-protein-coupled inwardly rectifying potassium (GIRK) channels were carried out in human atrial myocytes. A Phase I multiple-dose trial studied the pharmacokinetics, pharmacodynamics and safety of BAF312 in 48 healthy subjects.

KEY RESULTS

BAF312 effectively suppressed EAE in rats by internalizing S1P₁ receptors, rendering them insensitive to the egress signal from lymph nodes. In healthy volunteers, BAF312 caused preferential decreases in CD4⁺ T cells, T_naïve, T_{central memory} and B cells within 4–6 h. Cell counts returned to normal ranges within a week after stopping treatment, in line with the elimination half-life of BAF312. Despite sparing S1P₃ receptors (associated with bradycardia in mice), BAF312 induced rapid, transient (day 1 only) bradycardia in humans. BAF312-mediated activation of GIRK channels in human atrial myocytes can fully explain the bradycardia.

CONCLUSION AND IMPLICATIONS

This study illustrates species-specific differences in S1P receptor specificity for first-dose cardiac effects. Based on its profound but rapidly reversible inhibition of lymphocyte trafficking, BAF312 may have potential as a treatment for immune-mediated diseases.