Paul Ritschl

Dr. Paul Ritschl

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Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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10 May 2020 in American Journal of Transplantation
Verified
Journal Article
Open access
PRPaul Ritschl
Paul Ritschl
NNNora Nevermann
Nora Nevermann
LWLeke Wiering
Leke Wiering
HWHelen H. Wu
Helen H. Wu
PMPhilipp Moroder
Philipp Moroder
JPJohann Pratschke
Johann Pratschke
The ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has a drastic impact on national health care systems. Given the overwhelming demand on facility capacity, the impact on all health care sectors has to be addressed. Solid organ transplantation represents a field with a high demand on staff, intensive care units, and follow-up facilities. The great therapeutic value of organ transplantation has to be weighed against mandatory constraints of health care capacities. In addition, the management of immunosuppressed recipients has to be reassessed during the ongoing coronavirus disease 2019 (COVID-19) pandemic. In addressing these crucial questions, transplant physicians are facing a total lack of scientific evidence. Therefore, the aim of this study was to offer an approach of consensus-based guidance, derived from individual information of 22 transplant societies. Key recommendations were extracted and the degree of consensus among different organizations was calculated. A high degree of consensus was found for temporarily suspending nonurgent transplant procedures and living donation programs. Systematic polymerase chain reaction-based testing of donors and recipients was broadly recommended. Additionally, more specific aspects (eg, screening of surgical explant teams and restricted use of marginal donor organs) were included in our analysis. This study offers a novel approach to informed guidance for health care management when a priori no scientific evidence is available.

19 July 2022 in American Journal of Transplantation
Verified
Journal Article
Open access
AHAn He
An He
ASAttia Sarwar
Attia Sarwar
LTLinda Marie Laura Thole
Linda Marie Laura Thole
JSJanine Siegle
Janine Siegle
ASArne Sattler
Arne Sattler
KKKatja Kotsch
Katja Kotsch
Donor age is a major risk factor for allograft outcome in kidney transplantation. The underlying cellular mechanisms and the recipient's immune response within an aged allograft have yet not been analyzed. A comprehensive immunophenotyping of naïve and transplanted young versus aged kidneys revealed that naïve aged murine kidneys harbor significantly higher frequencies of effector/memory T cells, whereas regulatory T cells were reduced. Aged kidney-derived CD8+ T cells produced more IFNγ than their young counterparts. Senescent renal CD8+ T and NK cells upregulated the cytotoxicity receptor NKG2D and the enrichment of memory-like CD49a+ CXCR6+ NK cells was documented in aged naïve kidneys. In the C57BL/6 to BALB/c kidney transplantation model, recipient-derived T cells infiltrating an aged graft produced significantly more IFNγ, granzyme B and perforin on day 7 post-transplantation, indicating an enhanced inflammatory, cytotoxic response towards the graft. Pre-treatment of aged kidney donors with the senolytic drug ABT-263 changed the recipient-derived effector molecule profile to significantly reduced levels of IFNγ and IL-10 compared to controls. Graft function after ABT-263 pre-treatment was significantly improved 28 days post kidney transplantation. In conclusion, renal senescence also occurs at the immunological level (inflamm-aging) and aged organs provoke an altered recipient-dominated immune response in the graft.

16 March 2021 in BMC Surgery
Verified
Journal Article
Open access
PDF file
MSMaximilian Sohn
Maximilian Sohn
AAAyman Agha
Ayman Agha
IIIgors Iesalnieks
Igors Iesalnieks
FGFelix Gundling
Felix Gundling
JPJaroslav Presl
Jaroslav Presl
PRPaul Ritschl
Paul Ritschl
The best treatment for perforated colonic diverticulitis with generalized peritonitis is still under debate. Concurrent strategies are resection with primary anastomosis (PRA) with or without diverting ileostomy (DI), Hartmann’s procedure (HP), laparoscopic lavage (LL) and damage control surgery (DCS). This review intends to systematically analyze the current literature on DCS. DCS consists of two stages. Emergency surgery: limited resection of the diseased colon, oral and aboral closure, lavage, vacuum-assisted abdominal closure. Second look surgery after 24–48 h: definite reconstruction with colorectal anastomosis (−/ + DI) or HP after adequate resuscitation. The review was conducted in accordance to the PRISMA-P Statement. PubMed/MEDLINE, Cochrane central register of controlled trials (CENTRAL) and EMBASE were searched using the following term: (Damage control surgery) AND (Diverticulitis OR Diverticulum OR Peritonitis). Eight retrospective studies including 256 patients met the inclusion criteria. No randomized trial was available. 67% of the included patients had purulent, 30% feculent peritonitis. In 3% Hinchey stage II diverticulitis was found. In 49% the Mannheim peritonitis index (MPI) was greater than 26. Colorectal anastomosis was constructed during the course of the second surgery in 73%. In 15% of the latter DI was applied. The remaining 27% received HP. Postoperative mortality was 9%, morbidity 31% respectively. The anastomotic leak rate was 13%. 55% of patients were discharged without a stoma. DCS is a safe technique for the treatment of acute perforated diverticulitis with generalized peritonitis, allowing a high rate of colorectal anastomosis and stoma-free hospital discharge in more than half of the patients.

5 December 2020 in Hepatology Communications
Verified
Journal Article
Open access
PDF file
SMSimon Moosburner
Simon Moosburner
ISIgor M. Sauer
Igor M. Sauer
FFFrank Förster
Frank Förster
TWThomas Winklmann
Thomas Winklmann
JGJoseph Maria George Vernon Gassner
Joseph Maria George Vernon Gassner
NRNathanael Raschzok
Nathanael Raschzok
Concepts to ameliorate the continued mismatch between demand for liver allografts and supply include the acceptance of allografts that meet extended donor criteria (ECD). ECD grafts are generally associated with an increased rate of complications such as early allograft dysfunction (EAD). The costs of liver transplantation for the health care system with respect to specific risk factors remain unclear and are subject to change. We analyzed 317 liver transplant recipients from 2013 to 2018 for outcome after liver transplantation and hospital costs in a German transplant center. In our study period, 1‐year survival after transplantation was 80.1% (95% confidence interval: 75.8%‐84.6%) and median hospital stay was 33 days (interquartile rage: 24), with mean hospital costs of €115,924 (SD €113,347). There was a positive correlation between costs and laboratory Model for End‐Stage Liver Disease score (rs = 0.48, P < 0.001), and the development of EAD increased hospital costs by €26,229. ECD grafts were not associated with a higher risk of EAD in our cohort. When adjusting for recipient‐associated risk factors such as laboratory Model for End‐Stage Liver Disease score, recipient age, and split liver transplantation with propensity score matching, only EAD and cold ischemia increased total costs. Conclusion: Our data show that EAD leads to significantly higher hospital costs for liver transplantation, which are primarily attributed to recipient health status. Strategies to reduce the incidence of EAD are needed to control costs in liver transplantation.

Verified
Journal Article
Open access
PDF file
FKFelix Krenzien
Felix Krenzien
SKShadi Katou
Shadi Katou
APAlba Papa
Alba Papa
BSBruno Sinn
Bruno Sinn
CBChristian Benzing
Christian Benzing
MSMoritz Schmelzle
Moritz Schmelzle
Donor organ quality is crucial for transplant survival and long-term survival of patients after liver transplantation. Besides bacterial and viral infections, endogenous damage-associated molecular patterns (DAMPs) can stimulate immune responses. Cell-free DNA (cfDNA) is one such DAMP that exhibits highly proinflammatory effects via DNA sensors. Herein, we measured cfDNA after liver transplantation and found elevated levels when organs from resuscitated donors were transplanted. High levels of cfDNA were associated with high C-reactive protein, leukocytosis as well as granulocytosis in the recipient. In addition to increased systemic immune responses, portal hepatitis was observed, which was associated with increased interface activity and a higher numbers of infiltrating neutrophils and eosinophils in the graft. In fact, the cfDNA was an independent significant factor in multivariate analysis and increased concentration of cfDNA was associated with inferior 1-year survival. Moreover, cfDNA levels were found to be decreased significantly during the postoperative course when patients underwent continuous veno-venous haemofiltration. In conclusion, patients receiving livers from resuscitated donors were characterised by high postoperative cfDNA levels. Those patients showed pronounced portal hepatitis and systemic inflammatory responses in the short term leading to a high mortality. Further studies are needed to evaluate the clinical relevance of cfDNA clearance by haemoadsorption and haemofiltration in vitro and in vivo.

29 January 2025 in Transplant International
Verified
Journal Article
Open access
PDF file
LWLeke Wiering
Leke Wiering
AAAnnette Aigner
Annette Aigner
MRMarieke van Rosmalen
Marieke van Rosmalen
BGBrigitta Globke
Brigitta Globke
TDTomasz Dziodzio
Tomasz Dziodzio
RLRobert Llinger
Robert Llinger
In liver allocation systems based on the Model for End-stage Liver Disease (MELD) score, sex inequities have been identified in countries with high organ donation rates. Whether similar inequities exist in regions with average to low donation rates remained unclear. We assessed the impact of sex on transplantation rates, waiting list mortality and post-transplant survival in 25,943 patients waitlisted for liver transplantation in Germany between 2003 and 2017 using competing risk analysis. Women are currently underrepresented on the waiting list (33.3%) and among transplant recipients (31.1%) compared to their proportion of severe liver disease cases (35.1%). The introduction of MELD-based allocation has worsened this disadvantage [HR before: 0.89 (0.81–0.98), after: 0.77 (0.74–0.81)]. Three key factors contribute to this disparity: Women have lower creatinine levels despite worse renal function, reducing their MELD score (median 1, 0–3). Second, exceptional MELD points are more frequently granted to men [HR 1.61 (1.54–1.69) compared to regular allocation]. Third, the small height of women has the highest impact on the probability of not being transplanted [adjusted HR 0.85 (0.81–0.9)]. Even in countries with lower organ donation rates, MELD-based allocation leads to sex inequity. Measures are needed to ensure sex-neutral liver allocation in MELD-based systems worldwide.