Feasibility and evaluation of high-fidelity simulation education for acute clinical toxicology.

To prepare medical students appropriately for the management of toxicological emergencies, we have developed a simulation-based medical education (SBME) training in acute clinical toxicology. Our aim is to report on the feasibility, evaluation and lessons learned of this training. Since 2019, each year approximately 180 fifth-year medical students are invited to participate in the SBME training. The training consists of an interactive lecture and two SBME stations. For each station, a team of students had to perform the primary assessment and management of an intoxicated patient. After the training, the students completed a questionnaire about their experiences and confidence in clinical toxicology. Overall, the vast majority of students agreed that the training provided a fun, interactive and stimulating way to teach about clinical toxicology. Additionally, they felt more confident regarding their skills in this area. Our pilot study shows that SBME training was well-evaluated and feasible over a longer period.

The Dutch list of essential drugs for undergraduate medical education: A modified Delphi study.

AIMS: Prescribing errors among junior doctors are common in clinical practice because many lack prescribing competence after graduation. This is in part due to inadequate education in clinical pharmacology and therapeutics (CP&T) in the undergraduate medical curriculum. To support CP&T education, it is important to determine which drugs medical undergraduates should be able to prescribe safely and effectively without direct supervision by the time they graduate. Currently, there is no such list with broad-based consensus. Therefore, the aim was to reach consensus on a list of essential drugs for undergraduate medical education in the Netherlands. METHODS: A two-round modified Delphi study was conducted among pharmacists, medical specialists, junior doctors and pharmacotherapy teachers from all eight Dutch academic hospitals. Participants were asked to indicate whether it was essential that medical graduates could prescribe specific drugs included on a preliminary list. Drugs for which ≥80% of all respondents agreed or strongly agreed were included in the final list. RESULTS: In all, 42 (65%) participants completed the two Delphi rounds. A total of 132 drugs (39%) from the preliminary list and two (3%) newly proposed drugs were included. CONCLUSIONS: This is the first Delphi consensus study to identify the drugs that Dutch junior doctors should be able to prescribe safely and effectively without direct supervision. This list can be used to harmonize and support the teaching and assessment of CP&T. Moreover, this study shows that a Delphi method is suitable to reach consensus on such a list, and could be used for a European list.

The impact of a summative national prescribing assessment and curriculum type on the development of the prescribing competence of junior doctors.

PURPOSE: The primary aim of this study was to investigate the effect of including the Dutch National Pharmacotherapy Assessment (DNPA) in the medical curriculum on the level and development of prescribing knowledge and skills of junior doctors. The secondary aim was to evaluate the relationship between the curriculum type and the prescribing competence of junior doctors. METHODS: We re-analysed the data of a longitudinal study conducted in 2016 involving recently graduated junior doctors from 11 medical schools across the Netherlands and Belgium. Participants completed three assessments during the first year after graduation (around graduation (+ / - 4 weeks), and 6 months, and 1 year after graduation), each of which contained 35 multiple choice questions (MCQs) assessing knowledge and three clinical case scenarios assessing skills. Only one medical school used the DNPA in its medical curriculum; the other medical schools used conventional means to assess prescribing knowledge and skills. Five medical schools were classified as providing solely theoretical clinical pharmacology and therapeutics (CPT) education; the others provided both theoretical and practical CPT education (mixed curriculum). RESULTS: Of the 1584 invited junior doctors, 556 (35.1%) participated, 326 (58.6%) completed the MCQs and 325 (58.5%) the clinical case scenarios in all three assessments. Junior doctors whose medical curriculum included the DNPA had higher knowledge scores than other junior doctors (76.7% [SD 12.5] vs. 67.8% [SD 12.6], 81.8% [SD 11.1] vs. 76.1% [SD 11.1], 77.0% [12.1] vs. 70.6% [SD 14.0], p < 0.05 for all three assessments, respectively). There was no difference in skills scores at the moment of graduation (p = 0.110), but after 6 and 12 months junior doctors whose medical curriculum included the DNPA had higher skills scores (both p < 0.001). Junior doctors educated with a mixed curriculum had significantly higher scores for both knowledge and skills than did junior doctors educated with a theoretical curriculum (p < 0.05 in all assessments). CONCLUSION: Our findings suggest that the inclusion of the knowledge focused DNPA in the medical curriculum improves the prescribing knowledge, but not the skills, of junior doctors at the moment of graduation. However, after 6 and 12 months, both the knowledge and skills were higher in the junior doctors whose medical curriculum included the DNPA. A curriculum that provides both theoretical and practical education seems to improve both prescribing knowledge and skills relative to a solely theoretical curriculum.

Electrical stimulation of the splenic nerve bundle ameliorates dextran sulfate sodium-induced colitis in mice.

BACKGROUND: Vagus nerve stimulation has been suggested to affect immune responses, partly through a neuronal circuit requiring sympathetic innervation of the splenic nerve bundle and norepinephrine (NE) release. Molecular and cellular mechanisms of action remain elusive. Here, we investigated the therapeutic value of this neuromodulation in inflammatory bowel disease (IBD) by applying electrical splenic nerve bundle stimulation (SpNS) in mice with dextran sulfate sodium (DSS)-induced colitis. METHODS: Cuff electrodes were implanted around the splenic nerve bundle in mice, whereupon mice received SpNS or sham stimulation. Stimulation was applied 6 times daily for 12 days during DSS-induced colitis. Colonic and splenic tissues were collected for transcriptional analyses by qPCR and RNA-sequencing (RNA-seq). In addition, murine and human splenocytes were stimulated with lipopolysaccharide (LPS) in the absence or presence of NE. Single-cell RNA-seq data from publicly available data sets were analyzed for expression of ß-adrenergic receptors (ß-ARs). RESULTS: Colitic mice undergoing SpNS displayed reduced colon weight/length ratios and showed improved Disease Activity Index scores with reduced Tumor Necrosis Factor α mRNA expression in the colon compared with sham stimulated mice. Analyses of splenocytes from SpNS mice using RNA-seq demonstrated specific immune metabolism transcriptome profile changes in myeloid cells. Splenocytes showed expression of ß-ARs in myeloid and T cells. Cytokine production was reduced by NE in mouse and human LPS-stimulated splenocytes. CONCLUSIONS: Together, our results demonstrate that SpNS reduces clinical features of colonic inflammation in mice with DSS-induced colitis possibly by inhibiting splenic myeloid cell activation. Our data further support exploration of the clinical use of SpNS for patients with IBD.

Do we become better prescribers after graduation: A 1-year international follow-up study among junior doctors.

AIM: The aim of this study was to investigate how the prescribing knowledge and skills of junior doctors in the Netherlands and Belgium develop in the year after graduation. We also analysed differences in knowledge and skills between surgical and nonsurgical junior doctors. METHODS: This international, multicentre (n = 11), longitudinal study analysed the learning curves of junior doctors working in various specialties via three validated assessments at about the time of graduation, and 6 months and 1 year after graduation. Each assessment contained 35 multiple choice questions (MCQs) on medication safety (passing grade ≥85%) and three clinical scenarios. RESULTS: In total, 556 junior doctors participated, 326 (58.6%) of whom completed the MCQs and 325 (58.5%) the clinical case scenarios of all three assessments. Mean prescribing knowledge was stable in the year after graduation, with 69% (SD 13) correctly answering questions at assessment 1 and 71% (SD 14) at assessment 3, whereas prescribing skills decreased: 63% of treatment plans were considered adequate at assessment 1 but only 40% at assessment 3 (P < .001). While nonsurgical doctors had similar learning curves for knowledge and skills as surgical doctors (P = .53 and P = .56 respectively), their overall level was higher at all three assessments (all P < .05). CONCLUSION: These results show that junior doctors' prescribing knowledge and skills did not improve while they were working in clinical practice. Moreover, their level was under the predefined passing grade. As this might adversely affect patient safety, educational interventions should be introduced to improve the prescribing competence of junior doctors.

The pharmacotherapy team: A novel strategy to improve appropriate in-hospital prescribing using a participatory intervention action method.

AIMS: Prescribing medication is a complex process that, when done inappropriately, can lead to adverse drug events, resulting in patient harm and hospital admissions. Worldwide cost is estimated at 42 billion USD each year. Despite several efforts in the past years, medication-related harm has not declined. The aim was to determine whether a prescriber-focussed participatory action intervention, initiated by a multidisciplinary pharmacotherapy team, is able to reduce the number of in-hospital prescriptions containing ≥1 prescribing error (PE), by identifying and reducing challenges in appropriate prescribing. METHODS: A prospective single-centre before- and after study was conducted in an academic hospital in the Netherlands. Twelve clinical wards (medical, surgical, mixed and paediatric) were recruited. RESULTS: Overall, 321 patients with a total of 2978 prescriptions at baseline were compared with 201 patients with 2438 prescriptions postintervention. Of these, m456 prescriptions contained ≥1 PE (15.3%) at baseline and 357 prescriptions contained ≥1 PEs (14.6%) postintervention. PEs were determined in multidisciplinary consensus. On some study wards, a trend toward a decreasing number of PEs was observed. The intervention was associated with a nonsignificant difference in PEs (incidence rate ratio 0.96, 95% confidence interval 0.83-1.10), which was unaltered after correction. The most important identified challenges were insufficient knowledge beyond own expertise, unawareness of guidelines and a heavy workload. CONCLUSION: The tailored interventions developed with and implemented by stakeholders led to a statistically nonsignificant reduction in inappropriate in-hospital prescribing after a 6-month intervention period. Our prescriber-focussed participatory action intervention identified challenges in appropriate in-hospital prescribing on prescriber- and organizational level.

Switching from a traditional undergraduate programme in (clinical) pharmacology and therapeutics to a problem-based learning programme.

PURPOSE: The pharmacology and clinical pharmacology and therapeutics (CPT) education during the undergraduate medical curriculum of NOVA Medical School, Lisbon, Portugal, was changed from a traditional programme (i.e. discipline-based, lectures) to a problem-based learning (PBL) programme (i.e. integrated, case-based discussions) without an increase in teaching hours. The aim of this study was to investigate whether this change improved the prescribing competencies of final-year medical students. METHODS: Final-year students from both programmes (2015 and 2019) were invited to complete a validated prescribing assessment and questionnaire. The assessment comprised 24 multiple-choice questions in three subdomains (working mechanism, side-effects and interactions/contraindications), and five clinical case scenarios of common diseases. The questionnaire focused on self-reported prescribing confidence, preparedness for future prescribing task and education received. RESULTS: In total, 36 (22%) final-year medical students from the traditional programme and 54 (23%) from the PBL programme participated. Overall, students in the PBL programme had significantly higher knowledge scores than students in the traditional programme (76% (SD 9) vs 67% (SD 15); p = 0.002). Additionally, students in the PBL programme made significantly fewer inappropriate therapy choices (p = 0.023) and fewer erroneous prescriptions than did students in the traditional programme (p = 0.27). Students in the PBL programme felt more confident in prescribing, felt better prepared for prescribing as junior doctor and completed more drug prescriptions during their medical training. CONCLUSION: Changing from a traditional programme to an integrated PBL programme in pharmacology and CPT during the undergraduate medical curriculum may improve the prescribing competencies of final-year students.

Morphometric analysis of the splenic artery using contrast-enhanced computed tomography (CT).

PURPOSE: To evaluate the morphology and course of the splenic artery, which might impact the surgical implantation of systems that stimulate the nerves surrounding the splenic artery. Experimental studies indicate that these nerves play an important part in immune modulation, and might be a potential target in the treatment of autoimmune diseases. METHODS: This retrospective cohort study made use of contrast-enhanced CT images from 40 male and 40 female patients (age 30-69) that underwent a CT examination of the aorta, kidneys or pancreas. Anatomic features were described including total splenic artery length, calibers, tortuosity, the presence of arterial loops and the branching pattern of the splenic artery. RESULTS: No age-gender-related differences could be found related to tortuosity or branching pattern. The length of splenic artery in contact with pancreatic tissue decreased with increasing age, but was not different between genders. Artery diameters were wider in male compared to female subjects. Loops of variable directions, that represent a part of the artery that curls out of the pancreatic tissue, were identified in each age-gender category and were present in nearly all subjects (86%). CONCLUSION: This study suggests that although some anatomic features of the splenic artery are subject to factors as age and gender, the tortuosity of the splenic artery is not age dependent. Most subjects had one or multiple loops, which can serve as a target for neuromodulatory devices. Future studies should investigate whether splenic nerve stimulation is safe and feasible.

Acetylcholine-producing T cells augment innate immune-driven colitis but are redundant in T cell-driven colitis.

Clinical trials suggest that vagus nerve stimulation presents an alternative approach to classical immune suppression in Crohn's disease. T cells capable of producing acetylcholine (ChAT+ T cells) in the spleen are essential mediators of the anti-inflammatory effect of vagus nerve stimulation. Besides the spleen, ChAT+ T cells are found abundantly in Peyer's patches of the small intestine. However, the role of ChAT+ T cells in colitis pathogenesis is unknown. Here, we made use of CD4creChATfl/fl mice (CD4ChAT-/- mice) lacking ChAT expression specifically in CD4+ T cells. Littermates (ChATfl/fl mice) served as controls. In acute dextran sulfate sodium (DSS)-induced colitis (7 days of 2% DSS in drinking water), CD4ChAT-/- mice showed attenuated colitis and lower intestinal inflammatory cytokine levels compared with ChATfl/fl mice. In contrast, in a resolution model of DSS-induced colitis (5 days of 2% DSS followed by 7 days without DSS), CD4ChAT-/- mice demonstrated a worsened colitis recovery and augmented colonic histological inflammation scores and inflammatory cytokine levels as compared with ChATfl/fl mice. In a transfer colitis model using CD4+CD45RBhigh T cells, T cells from CD4ChAT-/- mice induced a similar level of colitis compared with ChATfl/fl T cells. Together, our results indicate that ChAT+ T cells aggravate the acute innate immune response upon mucosal barrier disruption in an acute DSS-induced colitis model, whereas they are supporting the later resolution process of this innate immune-driven colitis. Surprisingly, ChAT expression in T cells seems redundant in the context of T cell-driven colitis.NEW & NOTEWORTHY By using different mouse models of experimental colitis, we provide evidence that in dextran sulfate sodium-induced colitis, ChAT+ T cells capable of producing acetylcholine worsen the acute immune response, whereas they support the later healing phase of this innate immune-driven colitis.

Outcomes of a Multicenter Training Program in Laparoscopic Pancreatoduodenectomy (LAELAPS-2).

OBJECTIVE: The aim of the study was to assess feasibility and outcomes of a multicenter training program in laparoscopic pancreatoduodenectomy (LPD). BACKGROUND: Whereas expert centers have reported promising outcomes of LPD, nationwide analyses have raised concerns on its safety, especially during the learning curve. Multicenter, structured LPD training programs reporting outcomes including the first procedures are lacking. No LPD had been performed in the Netherlands before this study. METHODS: During 2014-2016, 8 surgeons from 4 high-volume centers completed the Longitudinal Assessment and Realization of Laparoscopic Pancreatic Surgery (LAELAPS-2) training program in LPD, including detailed technique description, video training, and proctoring. In all centers, LPD was performed by 2 surgeons with extensive experience in pancreatic and laparoscopic surgery. Outcomes of all LPDs were prospectively collected. RESULTS: In total, 114 patients underwent LPD. Median pancreatic duct diameter was 3 mm [interquartile range (IQR = 2-4)] and pancreatic texture was soft in 74% of patients. The conversion rate was 11% (n = 12), median blood loss 350 mL (IQR = 200-700), and operative time 375 minutes (IQR = 320-431). Grade B/C postoperative pancreatic fistula occurred in 34% of patients, requiring catheter drainage in 22% and re-operation in 2%. A Clavien-Dindo grade ≥ III complication occurred in 43% of patients. Median length of hospital stay was 15 days (IQR = 9-25). Overall, 30-day and 90-day mortality were both 3.5%. Outcomes were similar for the first and second part of procedures. CONCLUSIONS: This LPD training program was feasible and ensured acceptable outcomes during the learning curve in all centers. Future studies should determine whether such a training program is applicable in other settings and assess the added value of LPD.

Are Dutch dental students and dental-care providers competent prescribers of drugs?

Dental students and dental-care providers should be able to prescribe drugs safely and effectively. As it is unknown whether this is the case, we assessed and compared the prescribing competence of dental students and dental-care providers in the Netherlands. In 2017, all Dutch final-year dental students and a random sample of all qualified general dental practitioners and dental specialists (oral and maxillofacial surgeons and orthodontists) were invited to complete validated prescribing knowledge-assessment and skills-assessment instruments. The knowledge assessment comprised 40 multiple-choice questions covering important drug topics. The skills assessment comprised three common clinical case scenarios. For the knowledge assessment, the response rates were 26 (20%) dental students, 28 (8%) general dental practitioners, and 19 (19%) dental specialists, and for the skills assessment the response rates were 14 (11%) dental students, eight (2%) general dental practitioners, and eight (8%) dental specialists. Dental specialists had higher knowledge scores (78% correct answers) than either dental practitioners (69% correct answers) or dental students (69% correct answers). A substantial proportion of all three groups made inappropriate treatment choices (35%-49%) and prescribing errors (47%-70%). Although there were some differences, dental students and dental-care providers in the Netherlands lack prescribing competence, which is probably because of poor prescribing education during under- and postgraduate dental training. Educational interventions are urgently needed.

The inflammatory response after laparoscopic and open pancreatoduodenectomy and the association with complications in a multicenter randomized controlled trial.

BACKGROUND: The systemic inflammatory response seen after surgery seems to be related to postoperative complications. A reduction of the inflammatory response through minimally invasive surgery might therefore be the mechanism via which postoperative outcome could be improved. The aim of this study was to investigate if postoperative inflammatory markers differed between laparoscopic (LPD) and open pancreatoduodenectomy (OPD) and if there was a relationship between inflammatory markers and the occurrence of postoperative complications. METHODS: A side study of the multicenter randomized controlled LEOPARD-2 trial comparing LPD to OPD was performed. Area under the curve (AUC) for plasma inflammatory markers, including interleukin (IL-) 6, IL-8 and C reactive protein (CRP) levels, were determined during the first 96 postoperative hours and compared between LPD and OPD, Clavien-Dindo ≥ III complications, and postoperative pancreatic fistula (POPF) grade B/C. RESULTS: Overall, 38 patients were included (18 LPD and 20 OPD). The median AUC of IL-6 was 627 (195-1378) after LPD vs. 338 (175-694)pg/mL after OPD, (p = 0.114). The AUC of IL-8 and CRP were comparable. IL-6 levels were higher in patients with a Clavien-Dindo ≥ III complication (634[309-1489] vs. 297 [171-680], p = 0.034) and POPF grade B/C (994 [534-3265] vs. 334 [173-704], p = 0.003). In patients with a POPF grade B/C, IL-6 levels tended to be higher after LPD, as compared to OPD (3533[IQR 1133-3533] vs. 715[IQR 39-1658], p = 0.053). CONCLUSION: LPD, as compared to OPD, did not reduce the postoperative inflammatory response. IL-6 levels were associated with postoperative complications and pancreatic fistula.

The Effect of Myopenia on the Inflammatory Response Early after Colorectal Surgery.

BACKGROUND: Myopenia (low skeletal muscle mass) is associated with an increased risk of complications following colorectal surgery, however, the underlying mechanism is poorly understood. This study investigates the effect of myopenia on the early postoperative systemic inflammatory response. MATERIALS AND METHODS: In 78 patients undergoing colorectal surgery, the presence of myopenia was preoperatively assessed using computed tomography images of the third lumbar vertebra. Interleukin-8 (IL-8) and soluble tumor necrosis factor receptor-1 (TNFRSF1A) were measured in plasma before and 4 h after start of surgery as part of a randomized controlled trial investigating the effect of perioperative gum chewing on the inflammatory response. Multivariable linear regression analysis was performed to assess the effect of myopenia on inflammatory markers while correcting for possible confounders. RESULTS: Four hours after start of surgery, IL-8 was higher in patients with myopenia than in patients without myopenia (352 ± 268 vs. 239 ± 211 pg/ml, P = 0.048), while TNFRSF1A was similar between groups. After adjusting for sex and the intervention with perioperative gum chewing, myopenia remained associated with higher postoperative IL-8 concentrations (P = 0.047). CONCLUSION: Myopenia may affect IL-8 early after colorectal surgery. However, more studies are needed to validate these findings.

Do final-year medical students have sufficient prescribing competencies? A systematic literature review.

AIMS: Prescribing errors are an important cause of patient safety incidents and are frequently caused by junior doctors. This might be because the prescribing competence of final-year medical students is poor as a result of inadequate clinical pharmacology and therapeutic (CPT) education. We reviewed the literature to investigate which prescribing competencies medical students should have acquired in order to prescribe safely and effectively, and whether these have been attained by the time they graduate. METHODS: PubMed, EMBASE and ERIC databases were searched from the earliest dates up to and including January 2017, using the terms 'prescribing', 'competence' and 'medical students' in combination. Articles describing or evaluating essential prescribing competencies of final-year medical students were included. RESULTS: Twenty-five articles describing, and 47 articles evaluating, the prescribing competencies of final-year students were included. Although there seems to be some agreement, we found no clear consensus among CPT teachers on which prescribing competencies medical students should have when they graduate. Studies showed that students had a general lack of preparedness, self-confidence, knowledge and skills, specifically regarding general and antimicrobial prescribing and pharmacovigilance. However, the results should be interpreted with caution, given the heterogeneity and methodological weaknesses of the included studies. CONCLUSIONS: There is considerable evidence that final-year students have insufficient competencies to prescribe safely and effectively, although there is a need for a greater consensus among CPT teachers on the required competencies. Changes in undergraduate CPT education are urgently required in order to improve the prescribing of future doctors.

The European List of Key Medicines for Medical Education: A Modified Delphi Study.

Rational prescribing is essential for the quality of health care. However, many final-year medical students and junior doctors lack prescribing competence to perform this task. The availability of a list of medicines that a junior doctor working in Europe should be able to independently prescribe safely and effectively without supervision could support and harmonize teaching and training in clinical pharmacology and therapeutics (CPT) in Europe. Therefore, our aim was to achieve consensus on such a list of medicines that are widely accessible in Europe. For this, we used a modified Delphi study method consisting of three parts. In part one, we created an initial list based on a literature search. In part two, a group of 64 coordinators in CPT education, selected via the Network of Teachers in Pharmacotherapy of the European Association for Clinical Pharmacology and Therapeutics, evaluated the accessibility of each medicine in his or her country, and provided a diverse group of experts willing to participate in the Delphi part. In part three, 463 experts from 24 European countries were invited to participate in a 2-round Delphi study. In total, 187 experts (40%) from 24 countries completed both rounds and evaluated 416 medicines, 98 of which were included in the final list. The top three Anatomical Therapeutic Chemical code groups were (1) cardiovascular system (n = 23), (2) anti-infective (n = 21), and (3) musculoskeletal system (n = 11). This European List of Key Medicines for Medical Education could be a starting point for country-specific lists and could be used for the training and assessment of CPT.

Splenic arterial neurovascular bundle stimulation in esophagectomy: A feasibility and safety prospective cohort study.

Introduction: The autonomic nervous system is a key regulator of inflammation. Electrical stimulation of the vagus nerve has been shown to have some preclinical efficacy. However, only a few clinical studies have been reported to treat inflammatory diseases. The present study evaluates, for the first time, neuromodulation of the splenic arterial neurovascular bundle (SpA NVB) in patients undergoing minimally invasive esophagectomy (MIE), in which the SpA NVB is exposed as part of the procedure. Methods: This single-center, single-arm study enrolled 13 patients undergoing MIE. During the abdominal phase of the MIE, a novel cuff was placed around the SpA NVB, and stimulation was applied. The primary endpoint was the feasibility and safety of cuff application and removal. A secondary endpoint included the impact of stimulation on SpA blood flow changes during the stimulation, and an exploratory point was C-reactive protein (CRP) levels on postoperative day (POD) 2 and 3. Results: All patients successfully underwent placement, stimulation, and removal of the cuff on the SpA NVB with no adverse events related to the investigational procedure. Stimulation was associated with an overall reduction in splenic arterial blood flow but not with changes in blood pressure or heart rate. When compared to historic Propensity Score Matched (PSM) controls, CRP levels on POD2 (124 vs. 197 mg/ml, p = 0.032) and POD3 (151 vs. 221 mg/ml, p = 0.033) were lower in patients receiving stimulation. Conclusion: This first-in-human study demonstrated for the first time that applying a cuff around the SpA NVB and subsequent stimulation is safe, feasible, and may have an effect on the postoperative inflammatory response following MIE. These findings suggest that SpA NVB stimulation may offer a new method for immunomodulatory therapy in acute or chronic inflammatory conditions.

Age-Related Variation in Sympathetic Nerve Distribution in the Human Spleen.

Introduction: The cholinergic anti-inflammatory pathway (CAIP) has been proposed as an efferent neural pathway dampening the systemic inflammatory response via the spleen. The CAIP activates the splenic neural plexus and a subsequent series of intrasplenic events, which at least require a close association between sympathetic nerves and T cells. Knowledge on this pathway has mostly been derived from rodent studies and only scarce information is available on the innervation of the human spleen. This study aimed to investigate the sympathetic innervation of different structures of the human spleen, the topographical association of nerves with T cells and age-related variations in nerve distribution. Materials and Methods: Spleen samples were retrieved from a diagnostic archive and were allocated to three age groups; neonates, 10-25 and 25-70 years of age. Sympathetic nerves and T cells were identified by immunohistochemistry for tyrosine hydroxylase (TH) and the membrane marker CD3, respectively. The overall presence of sympathetic nerves and T cells was semi-automatically quantified and expressed as total area percentage. A predefined scoring system was used to analyze the distribution of nerves within different splenic structures. Results: Sympathetic nerves were observed in all spleens and their number appeared to slightly increase from birth to adulthood and to decrease afterward. Irrespective to age, more than halve of the periarteriolar lymphatic sheaths (PALSs) contained sympathetic nerves in close association with T cells. Furthermore, discrete sympathetic nerves were observed in the capsule, trabeculae and red pulp and comparable to the total amount of sympathetic nerves, showed a tendency to decrease with age. No correlation was found between the number of T cells and sympathetic nerves. Conclusion: The presence of discrete sympathetic nerves in the splenic parenchyma, capsule and trabecular of human spleens could suggest a role in functions other than vasoregulation. In the PALS, sympathetic nerves were observed to be in proximity to T cells and is suggestive for the existence of the CAIP in humans. Since sympathetic nerve distribution shows interspecies and age-related variation, and our general understanding of the relative and spatial contribution of splenic innervation in immune regulation is incomplete, it remains difficult to estimate the anti-inflammatory potential of targeting splenic nerves in patients.