Donor Macrophages Modulate Rejection After Heart Transplantation.

BACKGROUND: Cellular rejection after heart transplantation imparts significant morbidity and mortality. Current immunosuppressive strategies are imperfect, target recipient T cells, and have adverse effects. The innate immune response plays an essential role in the recruitment and activation of T cells. Targeting the donor innate immune response would represent the earliest interventional opportunity within the immune response cascade. There is limited knowledge about donor immune cell types and functions in the setting of cardiac transplantation, and no current therapeutics exist for targeting these cell populations. METHODS: Using genetic lineage tracing, cell ablation, and conditional gene deletion, we examined donor mononuclear phagocyte diversity and macrophage function during acute cellular rejection of transplanted hearts in mice. We performed single-cell RNA sequencing on donor and recipient macrophages and monocytes at multiple time points after transplantation. On the basis of our imaging and single-cell RNA sequencing data, we evaluated the functional relevance of donor CCR2+ (C-C chemokine receptor 2) and CCR2- macrophages using selective cell ablation strategies in donor grafts before transplant. Last, we performed functional validation that donor macrophages signal through MYD88 (myeloid differentiation primary response protein 88) to facilitate cellular rejection. RESULTS: Donor macrophages persisted in the rejecting transplanted heart and coexisted with recipient monocyte-derived macrophages. Single-cell RNA sequencing identified donor CCR2+ and CCR2- macrophage populations and revealed remarkable diversity among recipient monocytes, macrophages, and dendritic cells. Temporal analysis demonstrated that donor CCR2+ and CCR2- macrophages were transcriptionally distinct, underwent significant morphologic changes, and displayed unique activation signatures after transplantation. Although selective depletion of donor CCR2- macrophages reduced allograft survival, depletion of donor CCR2+ macrophages prolonged allograft survival. Pathway analysis revealed that donor CCR2+ macrophages are activated through MYD88/nuclear factor kappa light chain enhancer of activated B cells signaling. Deletion of MYD88 in donor macrophages resulted in reduced antigen-presenting cell recruitment, reduced ability of antigen-presenting cells to present antigen to T cells, decreased emergence of allograft-reactive T cells, and extended allograft survival. CONCLUSIONS: Distinct populations of donor and recipient macrophages coexist within the transplanted heart. Donor CCR2+ macrophages are key mediators of allograft rejection, and deletion of MYD88 signaling in donor macrophages is sufficient to suppress rejection and extend allograft survival. This highlights the therapeutic potential of donor heart-based interventions.

Donor management using a specialized donor care facility is associated with higher organ utilization from drug overdose donors.

Drug overdoses have tripled in the United States over the last two decades. With the increasing demand for donor organs, one potential consequence of the opioid epidemic may be an increase in suitable donor organs. Unfortunately, organs from donors dying of drug overdose have poorer utilization rates than other groups of brain-dead donors, largely due to physician and recipient concerns about viral disease transmission. During the study period of 2011 to 2016, drug overdose donors (DODs) account for an increasingly greater proportion of the national donor pool. We show that a novel model of donor care, known as specialized donor care facility (SDCF), is associated with an increase in organ utilization from DODs compared to the conventional model of hospital-based donor care. This is likely related to the close relationship of the SDCF with the transplant centers, leading to improved communication and highly efficient donor care.

Role of donor macrophages after heart and lung transplantation.

Since the 1960s, heart and lung transplantation has remained the optimal therapy for patients with end-stage disease, extending and improving quality of life for thousands of individuals annually. Expanding donor organ availability and immunologic compatibility is a priority to help meet the clinical demand for organ transplant. While effective, current immunosuppression is imperfect as it lacks specificity and imposes unintended adverse effects such as opportunistic infections and malignancy that limit the health and longevity of transplant recipients. In this review, we focus on donor macrophages as a new target to achieve allograft tolerance. Donor organ-directed therapies have the potential to improve allograft survival while minimizing patient harm related to global suppression of recipient immune responses. Topics highlighted include the role of ontogenically distinct donor macrophage populations in ischemia-reperfusion injury and rejection, including their interaction with allograft-infiltrating recipient immune cells and potential therapeutic approaches. Ultimately, a better understanding of how donor intrinsic immunity influences allograft acceptance and survival will provide new opportunities to improve the outcomes of transplant recipients.

Unintended consequences of changes to lung allocation policy.

Organ allocation for transplantation aims to balance the principles of justice and medical utility to optimally utilize a scarce resource. To address practical considerations, the United States is divided into 58 donor service areas (DSA), each constituting the first unit of allocation. In November 2017, in response to a lawsuit in New York, an emergency action change to lung allocation policy replaced the DSA level of allocation for donor lungs with a 250 nautical mile circle around the donor hospital. Similar policy changes are being implemented for other organs including heart and liver. Findings from a recent US Department of Health and Human Services report, supplemented with data from our institution, suggest that the emergency policy has not resulted in a change in the type of patients undergoing lung transplantation (LT) or early postoperative outcomes. However, there has been a significant decline in local LT, where donor and recipient are in the same DSA. With procurement teams having to travel greater distances, organ ischemic time has increased and median organ cost has more than doubled. We propose potential solutions for consideration at this critical juncture in the field of transplantation. Policymakers should choose equitable and sustainable access for this lifesaving discipline.

Clinical factors and high-resolution manometry predicting response to surgery for achalasia in children.

BACKGROUND: Esophageal achalasia is an uncommon condition in children. Although many interventions exist for the management of this disorder, esophageal (Heller) myotomy offers one of the most durable treatments. Our institution sought to review patients undergoing Heller myotomy concentrating on preoperative clinical factors that might predict postoperative outcomes. MATERIALS AND METHODS: All patients from January 1, 2007, to December 31, 2016, who underwent surgical treatment for achalasia at our tertiary pediatric hospital were identified and included in the study cohort. Electronic medical records for these patients were reviewed for clinical presentation variables, nonsurgical preoperative treatment, surgical approach, clinical response to surgery, need for postoperative treatment for ongoing symptoms, and high-resolution manometry (HRM) data. RESULTS: Twenty-six patients were included in the study, and all underwent myotomy with partial fundoplication (median age: 14.4 y [interquartile range 11.6-15.5]). At a median follow-up of 9.75 mo (interquartile range 3.5-21 mo), 16 (61.5%) patients reported good resolution of their dysphagia symptoms with surgery alone. Two patients (7.7%) had perforation of the gastrointestinal tract requiring surgical intervention. Eight patients (30.8%) required additional treatment for achalasia, with 5 (19.2%) of these undergoing additional surgery or endoscopic treatment. Patients who had preoperative dilation did not have good resolution of their dysphagia (n = 2; P = 0.037). Two of four patients undergoing postoperative dilation had preoperative dilation. None of these patients underwent preoperative manometry. There was a statistically significant difference in the ages of patients who required postoperative intervention and those who did not (14.1 versus 15.2 y old, respectively; P = 0.043). In patients who reported improvement of gastroesophageal reflux disease/reflux type symptoms after Heller myotomy, lower esophageal residual pressure (29.1 versus 18.7 mmHg; P = 0.018) on preoperative HRM was significantly higher than in those who did not report improvement after surgery. Higher upper esophageal mean pressure (66.6 versus 47.8 mmHg; P = 0.05) also predicted good gastroesophageal reflux disease/reflux symptom response in a similar manner. CONCLUSIONS: Current analysis suggests that preoperative dilation should be used cautiously and older patients may have a better response to surgery without need for postoperative treatment. In addition, preoperative HRM can aid in counseling patients in the risk of ongoing symptoms after surgery and may aid in determining if a fundoplication should be completed at the index procedure. Further research is needed to delineate these factors. LEVEL OF EVIDENCE: Level III.

Cosmetic outcome of skin adhesives versus transcutaneous sutures in laparoscopic port-site wounds: a prospective randomized controlled trial.

BACKGROUND: In an elective laparoscopic surgery, the cosmetic outcome becomes increasingly important. We conducted a study to evaluate the cosmetic outcome 3 months after a laparoscopic procedure and compared skin adhesive (SA) versus transcutaneous suture (TS). METHODS: A randomized, controlled, prospective study was conducted at a single study centre in Hamburg, Germany. Seventy-seven patients undergoing laparoscopic surgery with two lower abdominal port sites met the study requirements. It was decided randomly which port site would be closed with SA. The opposite site was closed with TS. Wounds were assessed after 7-12 days and after 3 months. Cosmetic outcome was measured by a visual analogue scale (VAS) completed by the patient, by the Hollander wound evaluation scale (HWES) and by the judgement of blinded investigators. RESULTS: Seventy-seven subjects were randomized. Complete data from the 3-month follow-up visit were available from 56 patients (72.7 %). The VAS scale ranged from 0 to 100 mm with "0" representing the best possible cosmetic outcome. Median satisfaction was 2 mm in the TS group and 3 mm in the SA group. The mean was high in both groups 4.6 (s = 13.1) versus 3.8 mm (s = 4.6). The outcome was neither clinically nor statistically significant. Cosmetic outcome was assessed by an investigator, and the HWES showed no difference. In regard to complications, no difference was found between SA and TS, either. CONCLUSIONS: In conclusion this study demonstrated that closure of laparoscopic port-site wounds leads to equivalent outcomes whether SAs or TSs are used. Complications are rare in both methods. Thus, SAs seem to be a valid alternative to sutures in laparoscopic surgery. Registration site: www.clinicaltrials.gov . REGISTRATION NUMBER: NCT02179723.

Lymphatic drainage from bronchus-associated lymphoid tissue in tolerant lung allografts promotes peripheral tolerance.

Tertiary lymphoid organs are aggregates of immune and stromal cells including high endothelial venules and lymphatic vessels that resemble secondary lymphoid organs and can be induced at nonlymphoid sites during inflammation. The function of lymphatic vessels within tertiary lymphoid organs remains poorly understood. During lung transplant tolerance, Foxp3+ cells accumulate in tertiary lymphoid organs that are induced within the pulmonary grafts and are critical for the local downregulation of alloimmune responses. Here, we showed that tolerant lung allografts could induce and maintain tolerance of heterotopic donor-matched hearts through pathways that were dependent on the continued presence of the transplanted lung. Using lung retransplantation, we showed that Foxp3+ cells egressed from tolerant lung allografts via lymphatics and were recruited into donor-matched heart allografts. Indeed, survival of the heart allografts was dependent on lymphatic drainage from the tolerant lung allograft to the periphery. Thus, our work indicates that cellular trafficking from tertiary lymphoid organs regulates immune responses in the periphery. We propose that these findings have important implications for a variety of disease processes that are associated with the induction of tertiary lymphoid organs.

Characterization of dendritic morphology and neurotransmitter phenotype of thoracic descending propriospinal neurons after complete spinal cord transection and GDNF treatment.

After spinal cord injury (SCI), poor regeneration of damaged axons of the central nervous system (CNS) causes limited functional recovery. This limited spontaneous functional recovery has been attributed, to a large extent, to the plasticity of propriospinal neurons, especially the descending propriospinal neurons (dPSNs). Compared with the supraspinal counterparts, dPSNs have displayed significantly greater regenerative capacity, which can be further enhanced by glial cell line-derived neurotrophic factor (GDNF). In the present study, we applied a G-mutated rabies virus (G-Rabies) co-expressing green fluorescence protein (GFP) to reveal Golgi-like dendritic morphology of dPSNs. We also investigated the neurotransmitters expressed by dPSNs after labeling with a retrograde tracer Fluoro-Gold (FG). dPSNs were examined in animals with sham injuries or complete spinal transections with or without GDNF treatment. Bilateral injections of G-Rabies and FG were made into the 2nd lumbar (L2) spinal cord at 3 days prior to a spinal cord transection performed at the 11th thoracic level (T11). The lesion gap was filled with Gelfoam containing either saline or GDNF in the injury groups. Four days post-injury, the rats were sacrificed for analysis. For those animals receiving G-rabies injection, the GFP signal in the T7-9 spinal cord was visualized via 2-photon microscopy. Dendritic morphology from stack images was traced and analyzed using a Neurolucida software. We found that dPSNs in sham injured animals had a predominantly dorsal-ventral distribution of dendrites. Transection injury resulted in alterations in the dendritic distribution with dorsal-ventral retraction and lateral-medial extension. Treatment with GDNF significantly increased the terminal dendritic length of dPSNs. The density of spine-like structures was increased after injury, and treatment with GDNF enhanced this effect. For the group receiving FG injections, immunohistochemistry for glutamate, choline acetyltransferase (ChAT), glycine, and GABA was performed in the T7-9 spinal cord. We show that the majority of FG retrogradely-labeled dPSNs were located in the Rexed Lamina VII. Over 90% of FG-labeled neurons were glutamatergic, with the other three neurotransmitters contributing less than 10% of the total. To our knowledge this is the first report describing the morphologic characteristics of dPSNs and their neurotransmitter expressions, as well as the dendritic response of dPSNs after transection injury and GDNF treatment.

Germany's disease management program: improving outcomes in congestive heart failure.

Hospital admissions among patients with congestive heart failure (CHF) are a major contributor to health care costs. A comprehensive disease management program for CHF was developed for private and statutory health insurance companies in order to improve health outcomes and reduce rehospitalization rates and costs. The program comprises care calls, written training material, telemetric monitoring, and health reports. Currently, 909 members from six insurance companies are enrolled. Routine evaluation, based on medical data warehouse software, demonstrates benefits in terms of improved health outcomes and processes of care. Economical evaluation of claims data indicates significant cost savings in a pre/post study design.

[Patient-oriented healthcare programs. Concepts and practical experience in the field of chronic heart failure]. / Patientenzentrierte Gesundheitsprogramme. Konzeption und praktische Erfahrungen am Beispiel der Indikation chronische Herzinsuffizenz.

Disease management programs (DMP) have been recently introduced in the German statutory healthcare sector by federal law. These compulsory programs are aimed at enhancing guideline-based treatment by primary care physicians. Based on a systematic analysis of disease models and deficits in healthcare delivery, patient-oriented DMP offer an alternative approach. Their standardized services include care calls, written educational material, reminder systems, health reports, and optional telemetric monitoring. As an example of this approach, the medical results of 151 patients participating in a comprehensive chronic heart failure (CHF) program were evaluated. Within the observation period of 12 months, the number of patients receiving appropriate prescriptions (ACE inhibitors, diuretics, or beta blockers) rose significantly. In many patients there was a remission of CHF key symptoms (leg edema, shortness of breath, dizziness). The daily weight monitoring was particularly appreciated by the patients. For further development of patient-oriented DMP in the German healthcare system, it will be crucial that financial savings can be convincingly demonstrated besides the clinical benefits. These include quality of life, particularly for those chronic conditions in which patient self-management has a large impact on disease course.

Association of lung function with declining ambient air pollution.

Recent studies have found a declining prevalence of respiratory infections in East German children, along with a tremendous improvement of air pollution since 1990. The present study evaluates the effects of improved air quality on lung function. Three consecutive cross-sectional surveys of schoolchildren ages 11-14 years from three communities in East Germany were performed in 1992-1993, 1995-1996, and 1998-1999. Lung function tests were available from 2,493 children. The annual mean of total suspended particulates (TSP) declined from 79 to 25 micro g/m(3), whereas levels for sulfur dioxide declined from 113 to 6 micro g/m(3). Mean forced vital capacity (FVC) and forced expiratory volume in 1 sec (FEV(1)) of the children increased from 1992-1993 to 1998-1999. The adjusted percent change of the geometric mean of FVC was 4.7% for a 50 micro g/m(3) decrease of TSP (p = 0.043) and 4.9% for a decrement of 100 micro g/m(3) SO(2) (p = 0.029). Effects on FEV(1) were smaller and not statistically significant. Our study indicates that a reduction of air pollution in a short time period may improve children's lung function.

Association of hormone replacement therapy with bronchial hyper-responsiveness.

Postmenopausal hormone replacement therapy (HRT) has been linked to asthma in women, however, with inconsistent conclusions. This study examined the association of HRT with bronchial hyper-responsiveness (BHR). Eighty-five postmenopausal women completed a women-specific questionnaire and underwent methacholine challenge testing according to the protocol of the European community respiratory health survey. Associations of HRT use with BHR (based on a 20% fall in FEV1), mild BHR (10% fall in FEV1) or dichotomized dose-response slopes were analyzed by logistic regression, controlling for age, education, smoking and overweight. The 27 HRT users were less likely to show BHR compared to the 58 non-users (11% vs. 41%), multiply adjusted odds ratio (95% confidence interval) 0.12 (0.03, 0.55). Results for dose-response slopes were similar, while mild BHR showed no association with HRT use. These results point to a relaxing effect of estrogens on bronchial smooth muscle.

Temporal changes in blood lead levels of children in east Germany.

This analysis investigates the temporal changes in blood lead levels (BLL) in repeated cross-sectional surveys of 5-7 year old children conducted in 1992-93, 1995-96 and 1998-99 and in a prospective cohort from a smelter town and an agricultural control region in east Germany. The region of Hettstedt has a long history of mining and smelting resulting in high levels of heavy metal pollution whereas the region of Zerbst has no known industrial sources of heavy metals. In the region of Hettstedt lead content in ambient dust fall declined since the early 1990s due to the closure of many factories, whilst in Zerbst lead in ambient dust fall was constantly low in the 1990s. Blood lead levels decreased during the observation period both in children from the smelter town and in children from the agricultural control region. From 1992-93 to 1998-99 the mean BLLs of school entrants fell by 20% (41.6 to 33.3 micrograms/l) in Hettstedt and by 30% (34.2 to 23.8 micrograms/l) in Zerbst. In the same observation period mean BLLs of cohort children declined by 35% (41.9 to 27.3 micrograms/l) in Hettstedt and by 39% (32.3 to 19.8 micrograms/l) in Zerbst. At the beginning of the observation period cohort children were 5-7 years of age and were followed up to the age of 11-14. Adjustment for sociodemographic factors, city area and environmental uptake of lead did not influence the percentage changes in BLL of school-entrants. It seems that the decline in ambient lead fall had an impact on the body burden of lead, but the overall decrease in BLL in these two regions is caused by the overall decrease of lead in gasoline and thus in food.

Topical wound oxygen therapy in the treatment of severe diabetic foot ulcers: a prospective controlled study.

Diabetic foot ulcers (DFU) are common, difficult-to-treat, and prone to complications. A prospective, controlled study was conducted to: 1) examine the clinical efficacy of a pressurized topical oxygen therapy (TWO(2)) device in outpatients (N = 28) with severe DFU referred for care to a community wound care clinic and 2) assess ulcer reoccurrence rates after 24 months. Seventeen (17) patients received TWO(2) five times per week (60-minute treatment, pressure cycles between 5 and 50 mb) and 11 selected a silver-containing dressing changed at least twice per week (control). Patient demographics did not differ between treatment groups but wounds in the treatment group were more severe, perhaps as a result of selection bias. Ulcer duration was longer in the treatment (mean 6.1 months, SD 5.8) than in the control group (mean 3.2 months, SD 0.4) and mean baseline wound area was 4.1 cm2 (SD 4.3) in the treatment and 1.4 cm2 (SD 0.6) in the control group (P = 0.02). Fourteen (14) of 17 ulcers (82.4%) in the treatment group and five of 11 ulcers (45.5%) in the control group healed after a median of 56 and 93 days, respectively (P = 0.04). No adverse events were observed and there was no reoccurrence at the ulcer site after 24 months' follow-up in either group. Although the absence of randomization and blinding may have under- or overestimated the treatment effect of either group, the significant differences in treatment outcomes confirm the potential benefits of TWO(2) in the management of difficult-to-heal DFUs. Clinical efficacy and cost-effectiveness studies as well as studies to elucidate the mechanisms of action of TWO(2) are warranted.

Exposure to pets and allergies in children.

Currently, there is ongoing discussion regarding potential protective effects of exposure to pets during early childhood on the development of atopic disorders in children later in life. We used data from three consecutive cross-sectional surveys to study the relationship between contact with dogs, cats and other pets, and allergic diseases in schoolchildren 5-14 years of age. In three study areas of the former East Germany, 7,611 questionnaires were received from 5,360 different children who were examined between 1992 and 1999 as school entrants, or third- or sixth-graders. Allergic sensitization to common aeroallergens (birch, grass, mite, cat) was assessed by specific serum immunoglobulin E (IgE) concentrations [using radioallergosorbent testing (RAST)] for 85% of the children. After adjustment for possible confounders, inverse associations were found between contact with dogs in the first year of life and lifetime prevalences of asthma [odds ratio (OR) = 0.68; 95% confidence interval (CI): 0.43-1.08], hay fever (OR = 0.61; 95% CI: 0.39-0.95), eczema (OR = 0.76; 95% CI: 0.61-0.94), itchy rash (OR = 0.76; 95% CI: 0.61-0.94), and pollen sensitization (RAST >/= 4: OR = 0.56; 95% CI: 0.38-0.82). These effects were more pronounced for children with atopic parents. Similar associations were observed for current contact with dogs. We identified no clear relationships for the other pets (cats, rodents, birds), with the exception that children currently exposed to cats were more likely to be sensitized against cats. In conclusion, this study supports the hypothesis of a potential protective mechanism related to dog exposure in early life, especially for children of atopic parents. However, this association was found only for dogs and not for cats.

Improved air quality in reunified Germany and decreases in respiratory symptoms.

BACKGROUND: Previous research on air pollution effects has found associations with chronic adverse health effects even at the relatively low levels of ambient particulates currently measured in most urban areas. METHODS: We assessed the impact of declines of total suspended particulates and sulfur dioxide in eastern Germany after reunification on the prevalence of nonallergic respiratory disorders in children. In the 1990s, particle mass (total suspended particulates) and sulfur dioxide declined, whereas number concentrations of nucleation-mode particles (10-30 nm) increased. In three study areas, questionnaires for 7,632 children between 5 and 14 years of age were collected in three phases: 1992-1993, 1995-1996, and 1998-1999. RESULTS: Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for a 50-microg/m3 increment in total suspended particulates were 3.0 (CI = 1.7-5.3) for bronchitis, 2.6 (CI = 1.0-6.6) for sinusitis, and 1.9 (CI = 1.2-3.1) for frequent colds. The effect sizes for a 100-microg/m3 increment in sulfur dioxide were similar. The effect estimates for ambient total suspended particulates and sulfur dioxide were stronger among children not exposed to gas stove emissions, visible molds or dampness, cats, or environmental tobacco smoke. CONCLUSIONS: The decreasing prevalence of nonallergic respiratory symptoms, along with improvements in ambient particle mass and sulfur dioxide (but not in nucleation-mode particles), indicates the reversibility of adverse health effects in children. This adds further evidence of a causal association between combustion-related air pollutants and childhood respiratory symptoms.