Application of enzyme-linked immunosorbent assay to detect antimicrobial peptides in human intestinal lumen

Intestinal transplantation is the definitive treatment for intestinal failure. However, tissue rejection and graft-versus-host disease are relatively common complications, necessitating aggressive immunosuppression that can itself pose further complications. Tracking intraluminal markers in ileal effluent from standard ileostomies may present a noninvasive and sensitive way to detect developing pathology within the intestinal graft. This would be an improvement compared to current assessments, which are limited by poor sensitivity and specificity, contributing to under or over-immunosuppression, respectively, and by the need for invasive biopsies. Herein, we report an approach to reproducibly analyze ileal fluid obtained through stoma sampling for antimicrobial peptide/protein concentrations, reasoning that these molecules may provide an assessment of intestinal homeostasis and levels of intestinal inflammation over time. Concentrations of lysozyme (LYZ), myeloperoxidase (MPO), calprotectin (S100A8/A9) and β-defensin 2 (DEFB2) were assessed using adaptations of commercially available enzyme-linked immunosorbent assays (ELISAs). The concentration of α-defensin 5 (DEFA5) was assessed using a newly developed sandwich ELISA. Our data support that with proper preparation of ileal effluent specimens, precise and replicable determination of antimicrobial peptide/protein concentrations can be achieved for each of these target molecules via ELISA. This approach may prove to be reliable as a clinically useful assessment of intestinal homeostasis over time for patients with ileostomies.

Covid-19, HLA, and race common link: A novel hypothesis

The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) accountable for the coronavirus disease 2019 (Covid-19) prompted a catastrophic pandemic striking millions of people with diverse presentations, from asymptomatic to severe, potentially lethal disease requiring unprecedented levels of specialized care and extraordinary resources that have overwhelmed healthcare systems around the world. In this detailed communication we postulating a novel hypothesis, based on the viral replication and transplantation immunology. This based on reviewing published journal articles and text book chapters to account for variable mortality and degrees of morbidity among various race and origins. Homo sapiens evolution over millions of years, for that the matter the origin of any biologic form of life form initiated by microorganisms. The entire body of a human has several millions of bacterial and viral genomes incorporated over millions of years. Perhaps the answer or a clue lies how compatible a foreign genomic sequence fits into three billion copies of human genome.

Role of tertiary lymphoid organs in the regulation of immune responses in the periphery

Tertiary lymphoid organs (TLOs) are collections of immune cells resembling secondary lymphoid organs (SLOs) that form in peripheral, non-lymphoid tissues in response to local chronic inflammation. While their formation mimics embryologic lymphoid organogenesis, TLOs form after birth at ectopic sites in response to local inflammation resulting in their ability to mount diverse immune responses. The structure of TLOs can vary from clusters of B and T lymphocytes to highly organized structures with B and T lymphocyte compartments, germinal centers, and lymphatic vessels (LVs) and high endothelial venules (HEVs), allowing them to generate robust immune responses at sites of tissue injury. Although our understanding of the formation and function of these structures has improved greatly over the last 30 years, their role as mediators of protective or pathologic immune responses in certain chronic inflammatory diseases remains enigmatic and may differ based on the local tissue microenvironment in which they form. In this review, we highlight the role of TLOs in the regulation of immune responses in chronic infection, chronic inflammatory and autoimmune diseases, cancer, and solid organ transplantation.

Evaluation of immunosuppression protocols for MHC-matched allogeneic iPS cell-based transplantation using a mouse skin transplantation model

BACKGROUND

Off-the-shelf major histocompatibility complex (MHC)-matched iPS cells (iPSC) can potentially initiate host immune responses because of the existence of numerous minor antigens. To suppress allo-immune responses, combination of immunosuppressants is usually used, but its efficacy to the allogeneic iPSC-based transplantation has not been precisely evaluated.

METHODS

Three transplantation models were used in this study; MHC-matched, minor antigen-mismatched mouse skin or iPSC-graft transplantation, and fully allogeneic human iPSC-derived liver organoid transplantation in immune-humanized mice. The recipients were treated with triple drugs combination (TDC; tacrolimus, methylprednisolone, and mycophenolate mofetil) or co-stimulatory molecule blockade (CB) therapy with some modifications. Graft survival as well as anti-donor T and B cell responses was analyzed.

RESULTS

In the mouse skin transplantation model, immunological rejection caused by the minor antigen-mismatch ranged from mild to severe according to the donor-recipient combination. The TDC treatment could apparently control the mild skin graft rejection when combined with a transient T cell depletion, but unexpected anti-donor T or B cell response was observed. On the other hand, CB therapy, particularly when combined with rapamycin treatment, was capable of attenuating both mild and severe skin graft rejection and allowing them to survive long-term without any unfavorable anti-donor immune responses. The efficacy of the CB therapy was confirmed in both mouse and human iPSC-derived graft transplantation.

CONCLUSIONS

The findings suggest that the CB-based treatment seems suitable to well manage the MHC-matched allogeneic iPSC-based transplantation. The TDC-based treatment may be also used to suppress the rejection, but screening of its severity prior to the transplantation seems to be needed.

Blending team-based learning and game-based learning in pharmacy education

BACKGROUND AND PURPOSE

Team-based learning (TBL) and game-based learning (GBL) are evidence-based active learning pedagogies. This study reports a learning experience that harnesses TBL and GBL benefits by blending both pedagogies (referred herein as TGL) in the facilitation of an immunology module for pharmacy students. The manuscript presents the rationale for using TGL, a description of the TGL process, student outcomes and satisfaction with the learning experience, and TGL applicability in different topics/disciplines.

EDUCATIONAL ACTIVITY AND SETTING

Sixty-five students were divided into 12 teams. Pre-class foundational readiness material was posted one week before class. Student readiness was assessed via individual and team readiness assurance tests (iRAT/tRAT) mapped to learning objectives, with immediate instructor-mediated debrief. Then student teams worked toward solving clinical applications using evidence-based clinical information databases, e.g., UpToDate, Lexicomp. Finally, students were engaged in a competitive online game designed to review topic's key concepts and evaluate student knowledge individually post-learning experience.

FINDINGS

TGL process fulfilled learning outcomes, indicated by successful student performance in module-related assessments: iRAT = 92.5% ± 1.2; tRAT = 98.3% ± 1.1; educational game = 71.5% ± 3.6; block exam = 82.1% ± 5.3. Student survey indicated that >90% of students are satisfied with readiness material, alignment of activities with learning outcomes, engagement in active learning, gaining new relevant knowledge/skills/mindset, and merging TBL with GBL.

SUMMARY

Combining GBL with TBL allowed assessing student performance individually after the learning experience, an element that is not part of canonical TBL structure, to ensure students are prepared for high-stake/board exams. TGL can be applied in diverse topics/disciplines and is generalizable to small and large cohorts.

Panel-Reactive and Donor-Specific Antibodies before Lung Transplantation can Affect Outcomes in Korean Patients Receiving Lung Transplantation

PURPOSE

Data on the distribution and impact of panel reactive antibodies (PRA) and donor specific antibodies (DSA) before lung transplantation in Asia, especially multi-center-based data, are limited. This study evaluated the prevalence of and effects of PRA and DSA levels before lung transplantations on outcomes in Korean patients using nationwide multicenter registry data.

MATERIALS AND METHODS

This study included 103 patients who received a lung transplant at five tertiary hospitals in South Korea between March 2015 and December 2017. Mortality, primary graft dysfunction (PGD), and bronchiolitis obliterans syndrome (BOS) were evaluated.

RESULTS

Sixteen patients had class I and/or class II PRAs exceeding 50%. Ten patients (9.7%) had DSAs with a mean fluorescence intensity (MFI) higher than 1000, six of whom had antibodies with a high MFI (≥2000). DSAs with high MFIs were more frequently observed in patients with high-grade PGD (≥2) than in those with no or low-grade (≤1) PGD. In the 47 patients who survived for longer than 9 months and were evaluated for BOS after the transplant, BOS was not related to DSA or PRA levels. One-year mortality was more strongly related to PRA class I exceeding 50% than that under 50% (0% vs. 16.7%, p=0.007).

CONCLUSION

Preoperative DSAs and PRAs are related to worse outcomes after lung transplantation. DSAs and PRAs should be considered when selecting lung transplant recipients, and recipients who have preoperative DSAs with high MFI values and high PRA levels should be monitored closely after lung transplantation.

Pre-transplant management and sensitisation in vascularised composite allotransplantation: A systematic review

INTRODUCTION

Vascularised composite allotransplantation (VCA) permits like-for-like reconstruction following extensive soft tissue injuries. The initial management of extensive soft tissue injury can lead to the development of anti-HLA antibodies through injury-related factors, transfusion and cadaveric grafting. The role of antibody-mediated rejection, donor-specific antibody formation and graft rejection in the context of VCA remains unclear. This systematic review aimed to determine whether pre-transplant management strategies influence immunological outcome following VCA.

METHODS

A systematic review of MEDLINE, EMBASE and CINAHL using a PRISMA-compliant methodology up to February 2019 was conducted. Pre-transplant, procedural and long-term outcome data were collected and recorded for all VCA recipients on an individual patient basis.

RESULTS

The search revealed 3,847 records of which 114 met inclusion criteria and reported clinical data related to 100 patients who underwent 129 VCA transplants. Trauma (50%) and burns (15%) were the most frequent indications for VCA. Of all 114 studies, only one reported acute resuscitative management. Fifteen patients were sensitised prior to reconstructive transplantation with an 80%%incidence of acute rejection in the first post-operative year. Seven patients demonstrated graft vasculopathy, only one of whom had demonstrated panel reactive antibodies.

CONCLUSIONS

Currently employed acute management strategies may predispose to the development of anti-HLA antibodies, adding to the already complex immunological challenge of VCA. To determine whether association between pre-transplant management and outcomes exists, further refinement of international registries is required.

New strategies for improving stem cell therapy in ischemic heart disease. Heart Fail Rev. 2016;21:737-752. [PMID: 27459850 DOI: 10.1007/s10741-016-9576-1]

Stem cell therapy is a promising approach to the treatment of ischemic heart disease via replenishing cell loss after myocardial infarction. Both preclinical studies and clinical trials have indicated that cardiac function improved consistently, but very modestly after cell-based therapy. This mainly attributed to low cell survival rate, engraftment and functional integration, which became the major challenges to regenerative medicine. In recent years, several new cell types have been developed to regenerate cardiomyocytes and novel delivery approaches helped to increase local cell retention. New strategies, such as cell pretreatment, gene-based therapy, tissue engineering, extracellular vesicles application and immunologic regulation, have surged and brought about improved cell survival and functional integration leading to better therapeutic effects after cell transplantation. In this review, we summarize these new strategies targeting at challenges of cardiac regenerative medicine and discuss recent evidences that may hint their effectiveness in the future clinical settings.

IMMUNOLOGICAL MONITORING IN TRANSPLANTATION

Sixty eight patients who had undergone live related donor renal transplantation (LRD), were evaluated for soluble interleukin-2 receptors (sIL-2R), tumour necrosis factor alpha (TNF-α) and autoantibodies against IgG(Fab')2 and IgG(Fc), at pre- and various post-transplant intervals. Serum sIL-2R levels were significantly elevated in hemodialysed patients awaiting transplantation (mean 259.2 ± 90.5 pmol/L) as compared to healthy volunteers (mean 52.6 ± 16.7 pmol/L). In 96 samples obtained from patients with well-functioning grafts (WFG), the post-transplant sIL-2R levels (135.6 ± 65.4 pmol/L) were significantly lower (p < 0.001) than their pretransplant values. Eight patients with cyclosporin-A (CsA) nephrotoxicity, 14 with reversible acute tubular necrosis (ATN) and 4 patients with partial surgical obstruction, revealed moderate levels (99.0 ± 13.7, 184.1 ± 47.5, 156.7 ± 40.4 pmol/L respectively). On the other hand, 29 patients with acute rejection episodes, 11 with chronic rejection and 8 with infections had significantly higher levels (307.9 ± 89.3, 253.3 ± 68.6,345 ± 110.6 pmol/L), (p < 0.001). TNF-α levels were also raised in rejection and infective episodes but were not statistically significant. Serum anti-IgG(Fab')2 levels were found higher (0.407 OD) in WFG as compared to those with declining graft functions (0.279 OD). On the contrary high pre- and post-transplant anti-IgG(Fc) activity was associated with increased graft rejection and lower survival rate.

SENSITIZATION STATE OF POTENTIAL LIVE RELATED DONOR RENAL TRANSPLANT PATIENTS

Sensitization state of 119 patients of end-stage renal disease registered for live related donor transplant was assessed by determining the panel reactive antibody (PRA) status and the donor-specific crossmatch positivity. Eighty one patients (69.1%) showed no PRA, whereas 27 (22.6%) had PRA less than 10% and the remaining 11 patients (9.2%) displayed PRA more than 10%. The lower level of sensitization was related to the short dialysis period, less number of blood transfusions, fewer female patiente, and lesser number of retransplants. Cross-match positive patients were in the higher PRA group (range 32-68%) as compared to 0-24% PRA in cross-match negative group.