Smoking exposure-induced bronchus-associated lymphoid tissue in donor lungs does not prevent tolerance induction after transplantation.

The presence of bronchus-associated lymphoid tissue (BALT) in donor lungs has been suggested to accelerate graft rejection after lung transplantation. Although chronic smoke exposure can induce BALT formation, the impact of donor cigarette use on alloimmune responses after lung transplantation is not well understood. Here, we show that smoking-induced BALT in mouse donor lungs contains Foxp3+ T cells and undergoes dynamic restructuring after transplantation, including recruitment of recipient-derived leukocytes to areas of pre-existing lymphoid follicles and replacement of graft-resident donor cells. Our findings from mouse and human lung transplant data support the notion that a donor's smoking history does not predispose to acute cellular rejection or prevent the establishment of allograft acceptance with comparable outcomes to nonsmoking donors. Thus, our work indicates that BALT in donor lungs is plastic in nature and may have important implications for modulating proinflammatory or tolerogenic immune responses following transplantation.

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.

Centralized Organ Recovery and Reconditioning Centers.

An increased focus on improving efficiency and decreasing costs has resulted in alternative models of donor management and organ recovery. The specialized donor care facility model provides highly efficient and cost-effective donor care at a free-standing facility, resulting in improved organ yield, shorter ischemic times, decreased travel, and fewer nighttime operations. Ex vivo lung perfusion (EVLP) improves utilization of extended criteria donor lungs, and centralized EVLP facilities have the potential to increase transplant volumes for smaller transplant programs in specified geographic regions. These alternative models are increasingly being used in the United States to improve waitlist mortality and combat the ongoing donor organ shortage.

Specialized Donor Care Facility Model and Advances in Management of Thoracic Organ Donors.

BACKGROUND: Donor hearts and lungs are more susceptible to the inflammatory physiologic changes that occur after brain death. Prior investigations have shown that protocolized management of potential organ donors can rehabilitate donor organs that are initially deemed unacceptable. In this review we discuss advances in donor management models with particular attention to the specialized donor care facility model. In addition we review specific strategies to optimize donor thoracic organs and improve organ yield in thoracic transplantation. METHODS: We performed a literature review by searching the PubMed database for medical subject heading terms associated with organ donor management models. We also communicated with our local organ procurement organization to gather published and unpublished information first-hand. RESULTS: The specialized donor care facility model has been shown to improve the efficiency of organ donor management and procurement while reducing costs and minimizing travel and its associated risks. Lung protective ventilation, recruitment of atelectatic lung, and hormone therapy (eg, glucocorticoids and triiodothyronine/thyroxine) are associated with improved lung utilization rates. Stroke volume-based resuscitation is associated with improved heart utilization rates, whereas studies evaluating hormone therapy (eg, glucocorticoids and triiodothyronine/thyroxine) have shown variable results. CONCLUSIONS: Lack of high-quality prospective evidence results in conflicting practices across organ procurement organizations, and best practices remain controversial. Future studies should focus on prospective, randomized investigations to evaluate donor management strategies. The specialized donor care facility model fosters a collaborative environment that encourages academic inquiry and is an ideal setting for these investigations.

Sterile inflammation in thoracic transplantation.

The life-saving benefits of organ transplantation can be thwarted by allograft dysfunction due to both infectious and sterile inflammation post-surgery. Sterile inflammation can occur after necrotic cell death due to the release of endogenous ligands [such as damage-associated molecular patterns (DAMPs) and alarmins], which perpetuate inflammation and ongoing cellular injury via various signaling cascades. Ischemia-reperfusion injury (IRI) is a significant contributor to sterile inflammation after organ transplantation and is associated with detrimental short- and long-term outcomes. While the vicious cycle of sterile inflammation and cellular injury is remarkably consistent amongst different organs and even species, we have begun understanding its mechanistic basis only over the last few decades. This understanding has resulted in the developments of novel, yet non-specific therapies for mitigating IRI-induced graft damage, albeit with moderate results. Thus, further understanding of the mechanisms underlying sterile inflammation after transplantation is critical for identifying personalized therapies to prevent or interrupt this vicious cycle and mitigating allograft dysfunction. In this review, we identify common and distinct pathways of post-transplant sterile inflammation across both heart and lung transplantation that can potentially be targeted.

Predictors of Treatment Failure Following De-escalation to a Fluoroquinolone in Culture-Negative Nosocomial Pneumonia.

Background: Little evidence exists for de-escalation of nosocomial pneumonia therapy without positive cultures. Objective: The purpose of this study was to identify potential predictors of treatment failure following de-escalation to a fluoroquinolone in culture-negative nosocomial pneumonia. Methods: The study involved a single-center, retrospective cohort of patients admitted with diagnosis of nosocomial pneumonia and positive chest radiography who received at least 24 hours of fluoroquinolone monotherapy following at least 24 hours of appropriate empirical antibiotics. Treatment failure was defined using a composite of all-cause death within 30 days of discharge, treatment re-escalation, or readmission for pneumonia within 30 days of discharge. The Cox proportional hazards model was used to analyze predictors of treatment failure. Duration of empirical antibiotics and significant univariable exploratory predictors were included in multivariable analysis. Results: Of 164 patients, 23 (14%) failed de-escalation. Duration of empirical antibiotics (68.5 ± 32.1 vs 65.8 ± 35 hours) was not associated with treatment failure in univariable (Hazard Ratio [HR] = 1.002 [95% CI = 0.991-1.013]) or multivariable analyses (HR = 1.003 [95% CI = 0.991-1.015]). Significant exploratory predictors on univariable analysis included active cancer, intensive care unit (ICU) admission at empirical initiation, APACHE II score, and steroid use ≥20-mg prednisone equivalent. ICU admission at empirical initiation (HR = 2.439 [95% CI = 1.048-5.676]) and steroid use ≥20-mg prednisone equivalent (HR = 2.946 [95% CI = 1.281-6.772]) were associated with treatment failure on multivariable analysis. Conclusion and Relevance: Duration of empirical antibiotics does not appear to influence failure of de-escalation to fluoroquinolone monotherapy in culture-negative nosocomial pneumonia.

Assessment of the quality of life in patients with bronchial asthma, before and after yoga: a randomised trial.

Yoga which is used as an adjunct treatment for bronchial asthma is gaining popularity throughout the world. The objective of this study was to assess the effect of yoga on quality of life in patients with bronchial asthma. 120 non-smoking male and female patients of asthma in the age group of 17-50 years were randomized into two groups i.e. Group A (Yoga group) and Group B (control group). All patients remained on their prescribed medication, but Group A patients practiced yoga breathing exercises for 8 weeks. Asthma Quality of Life Questionnaire (AQLQ) and diary record was used to assess quality of life, number and severity of asthmatic attacks, and the dosage of the medication required at baseline and after 8 weeks. Group A subjects showed a statistically significant improvement in "symptoms", "activities" and "environmental" domains of AQLQ at 8 weeks (p<0.01) and significant reduction in daily number and severity of attacks, and the dosage of medication required at 4 and 8 weeks (p<0.01) compared to the baseline. Yoga breathing exercises used adjunctively with standard pharmacological treatment significantly improved quality of life in patients with bronchial asthma.