Repetitive diacetyl vapor exposure promotes ubiquitin proteasome stress and precedes bronchiolitis obliterans pathology

Bronchiolitis obliterans (BO) is a devastating lung disease seen commonly after lung transplant, following severe respiratory tract infection or chemical inhalation exposure. Diacetyl (DA; 2,3-butanedione) is a highly reactive alpha-diketone known to cause BO when inhaled, however, the mechanisms of how inhalation exposure leads to BO development remains poorly understood. In the current work, we combined two clinically relevant models for studying the pathogenesis of DA-induced BO: (1) an in vivo rat model of repetitive DA vapor exposures with recovery and (2) an in vitro model of primary human airway epithelial cells exposed to pure DA vapors. Rats exposed to 5 consecutive days 200 parts-per-million DA 6 h per day had worsening survival, persistent hypoxemia, poor weight gain, and histologic evidence of BO 14 days after DA exposure cessation. At the end of exposure, increased expression of the ubiquitin stress protein ubiquitin-C accumulated within DA-exposed rat lung homogenates and localized primarily to the airway epithelium, the primary site of BO development. Lung proteasome activity increased concurrently with ubiquitin-C expression after DA exposure, supportive of significant proteasome stress. In primary human airway cultures, global proteomics identified 519 significantly modified proteins in DA-exposed samples relative to controls with common pathways of the ubiquitin proteasome system, endosomal reticulum transport, and response to unfolded protein pathways being upregulated and cell-cell adhesion and oxidation-reduction pathways being downregulated. Collectively, these two models suggest that diacetyl inhalation exposure causes abundant protein damage and subsequent ubiquitin proteasome stress prior to the development of chemical-induced BO pathology.

Role of CMV chemokine receptor M33 in airway graft rejection in a mouse transplant model

BACKGROUND

Cytomegalovirus (CMV) infection is a risk factor for bronchiolitis obliterans (BO), one form of chronic lung allograft dysfunction (CLAD). The viral chemokine receptor M33 is essential for successful spread of murine CMV to host salivary glands. In the present study we investigated the impact of M33 on chronic airway rejection.

METHODS

MHC I-mismatched tracheas of C·B10-H2^b/LilMcdJ mice were transplanted into BALB/c (H2^d) recipients and infected at different dates with wild type (WT) or M33-deleted (delM33) MCMV representing clinical settings of viral recipient (R)-donor (D)-serostatus: (D-/R+) or (D+/R-). Grafts were recovered for gene expression and histological / immunofluorescence analysis, respectively.

RESULTS

Evaluations showed significantly increased signs of chronic rejection in WT-infected mice compared to uninfected allografts seen in lower epithelium/lamina propria-ratio (ELR) (ELR 0.46 ± 0.07 [WT post] vs. ELR 0.66 ± 0.10 [non-inf.]; p < 0.05). The rejection in delM33-infected groups was significantly reduced vs. WT-infected groups (0.67 ± 0.04 [delM33 post]; vs. WT post p < 0.05). Furthermore, decreased rejection was observed in WT pre-infected compared to post-infected groups (0.56 ± 0.08 [WT pre]; vs. WT post p < 0.05). CD8⁺ T cell infiltration was significantly higher in WT-post compared to the delM33 infected or non-infected allografts.

CONCLUSIONS

These data support the role of the CMV in accelerating CLAD. The deletion of chemokine receptor M33 leads to attenuated rejection.

A Case of Paraneoplastic Pemphigus as a Preceding Manifestation of Underlying Follicular Lymphoma Treated with R-CHOP

Paraneoplastic pemphigus is a rare, life-threatening disorder associated with an underlying neoplasm, which presents with painful stomatitis and polymorphous skin lesions. Successful diagnosis of paraneoplastic pemphigus can lead to the diagnosis and treatment of the underlying malignancy. However, involvement of the respiratory system is typically unresponsive to treatment. Herein, we report the case of a 44-year-old female diagnosed with paraneoplastic pemphigus with underlying follicular lymphoma treated with a chemotherapy regimen including rituximab. Her skin lesions and underlying lymphoma responded to treatment, but bronchiolitis obliterans continued to progress and resulted in fatal respiratory failure.

Bronchiolitis obliterans following toxic epidermal necrolysis: a case report

Background

Toxic epidermal necrolysis (TEN) is a rare, acute and potentially fatal skin condition usually induced by drugs. Although much attention is focused on the life threatening acute cutaneous and sight threatening ocular manifestations of this disease, chronic pulmonary complications like bronchiolitis obliterans are occasionally encountered. However, little is known about its incidence, pathogenesis, clinical course and outcome in children recovering from TEN.

Case presentation

We report a five-year-old boy who presented four months after the first manifestation of drug-induced TEN with cough and shortness of breath and was subsequently diagnosed with bronchiolitis obliterans. He was treated with supportive therapy that improved his hypercapnia allowing him to be discharged on domiciliary oxygen, chest physiotherapy and bronchodilators.

Conclusions

This case highlights the need to be vigilant for adverse drug reactions and consider chronic pulmonary complications like Bronchiolitis Obliterans in children recovering from TEN.

Updated prevalence, predictors and treatment outcomes for bronchiolitis obliterans syndrome after allogeneic stem cell transplantation

INTRODUCTION

Bronchiolitis obliterans syndrome (BOS) after allogeneic haemopoietic stem cell transplant (HSCT) is an under-recognised and difficult to treat disease. This occurs in the context of limited clinical research and inconsistent diagnostic criteria.

METHOD

Retrospective data was collected on 275 patients who underwent allogeneic HSCT at an Australian tertiary hospital between 2007 and 2017. The prevalence of BOS, defined by 2014 National Institute of Health criteria, as well as predictors for BOS and mortality were determined. Treatment outcomes, using serial spirometry, were compared between patients who received early versus late immunosuppression for BOS.

RESULTS

The prevalence of BOS was 9.1%. Myeloablative conditioning (OR: 2.7, 95%CI: 1.13-6.50, p = 0.03) and extra-pulmonary chronic graft-versus-host disease (OR 2.62, 95% CI: 1.04-6.60, p = 0.04) were associated with BOS. There was reduced median survival in the BOS group compared with the non-BOS group, but this was not statistically significant (4.1years (IQR: 2.8, 6.8) versus 4.6years (IQR: 2.4, 7.8), respectively, p = 0.33). The vast majority (87.5%) of BOS patients failed to attain improvement in FEV1 at 12 months, regardless of treatment strategy. Patients who underwent a late immunosuppression strategy had worse mean FEV1 decline compared to those who received early immunosuppression (-36.3% versus -1.6%, respectively, p = 0.03).

CONCLUSION

BOS is a common and progressive disease following HSCT and is largely refractory to current treatment strategies. Compared to late immunosuppression, early augmentation of immunosuppression may slow lung function deterioration in the short term. However, further research is urgently needed to identify effective prevention and treatment strategies for BOS.

A case of bronchiolitis obliterans after living-donor renal transplantation

We herein report the case of a 20 year-old-man who developed bronchiolitis obliterans after living-donor renal transplantation. The patient presented with dyspnea on exertion and wheezing two years after renal transplantation, and spirometry showed an obstructive pattern. Surgical lung biopsy revealed subepithelial fibrosis that constricted and obstructed the intrabronchiolar space. Based on these findings, the patient was diagnosed with bronchiolitis obliterans. He was prescribed bronchodilators and azithromycin, and he achieved stable respiratory function for two years. The differential diagnosis of respiratory symptoms after renal transplantation includes opportunistic infection and drug-induced lung injury; however, bronchiolitis obliterans should also be considered.

Intractable diffuse pulmonary diseases: Manual for diagnosis and treatment

This manual has been compiled by a joint production committee with the Diffuse Lung Disease Assembly of the Japanese Respiratory Society (JRS) to provide a practical manual for the epidemiology, diagnosis, and treatment of intractable diffuse pulmonary diseases. The contents are based upon the results of research into these diseases by the Diffuse Pulmonary Diseases Study Group (principal researcher: Sakae Homma) supported by the FY2014-FY2016 Health and Labor Sciences Research Grant on Intractable Diseases. This manual focuses on: 1) pulmonary alveolar microlithiasis, 2) bronchiolitis obliterans, and 3) Hermansky-Pudlak Syndrome with interstitial pneumonia. As these are rare/intractable diffuse lung diseases (2 and 3 were first recognized as specified intractable diseases in 2015), there have not been sufficient epidemiological studies made, and there has been little progress in formulating diagnostic criteria and severity scales; however, the results of Japan's first surveys and research into such details are presented herein. In addition, the manual provides treatment guidance and actual cases for each disease, aiming to assist in the establishment of future modalities. The manual was produced with the goal of enabling clinicians specialized in respiratory apparatus to handle these diseases in clinical settings and of further advancing future research and treatment.

Esophageal Evaluation for Patients Undergoing Lung Transplant Evaluation: What Should We Do for Evaluation and Management

Lung transplantation is a high-risk, but lifesaving, procedure for patients with end-stage lung disease. Although 1-year survival is high, long-term survival is not nearly as high, due mainly to acute and chronic rejection. Bronchiolitis obliterans syndrome is the most common type of chronic rejection and often leads to poor outcomes. For this reason, esophageal testing in the lung transplant population has become a major issue, and this article discusses the evidence behind esophageal testing, the importance of esophageal dysmotility gastroesophageal reflux disease, both acidic and nonacidic reflux, and aspiration and the treatment of these findings.

Severe adenovirus pneumonia with hemophagocytic syndrome and respiratory failure

We report the case of an 18-month-old infant with severe serotype 3 adenovirus pneumonia, exceptionally associated with hemophagocytic syndrome. Treatment included cidofovir and mechanical ventilation for 13 days. The child developed chronic respiratory insufficiency due to bronchiectasis and bronchiolitis obliterans.

Effect of Ruxolitinib on Lung Function after Allogeneic Stem Cell Transplantation

Ruxolitinib, a selective Janus kinase (JAK)1/2 inhibitor, has recently been proposed for steroid-refractory chronic graft-versus host disease (cGVHD) after allogeneic hematopoietic stem cell transplantation (HSCT), particularly in severe skin cGVHD. Lung function impairment is common in severe skin cGVHD through concomitant bronchiolitis obliterans syndrome (BOS) or restrictive lung disease (RLD) from skin sclerosis. To date, no treatment has shown a benefit on lung function in this context. We retrospectively assessed the effect of ruxolitinib on lung function in a cohort of 70 patients diagnosed with sclerotic-type skin cGVHD between March 2015 and April 2018. Among these patients, 36 received ruxolitinib. To handle confounding by indication bias, exposure groups were matched on the propensity score to receive ruxolitinib, incorporating age, myeloablative conditioning, total body irradiation, BOS, forced expiratory volume in 1 second (FEV₁), forced vital capacity (FVC), and tobacco use at the time of cohort entry, as well as the time from transplantation. The 1:1 matching used a greedy-matching algorithm with replacement, with a caliper of 0.10. FVC and FEV₁ trajectories during follow-up were compared in the matched samples, using linear mixed-effects models. The median duration of follow-up of the 46 matched patients was 58 months (interquartile range, 32 to 84 months). Ten patients had an RLD (6 exposed, 4 unexposed), and 13 patients were diagnosed with BOS (8 exposed, 5 unexposed). FEV₁ decreased significantly over time independent of exposure to ruxolitinib (P < .0001). The FEV₁ trajectory was similar in the exposed patients and the unexposed patients (P = .11). In conclusion, ruxolitinib administration did not demonstrate any improvement in the course of respiratory function in allogeneic HSCT recipients with sclerotic-type skin cGVHD.

Sauropus androgynus L. Merr.-A phytochemical, pharmacological and toxicological review

ETHNOPHARMACOLOGICAL RELEVANCE

Sauropus androgynus L. Merr is an underexploited perennial shrub traditionally used as a medicinal plant in South Asia and Southeast Asia. The plant is regarded as not just a green vegetable for diet, but as a traditional herb for certain aliments. For instance, it has traditionally been used to relieve fever, to treat ulcers and diabetes, to promote lactation and eyesight, and to reduce obesity.

AIM OF THE STUDY

This paper aims to review the botany, phytochemistry, ethnopharmacology, and pharmacological activities of S. androgynus, and discuss the known chemical constituents at work in S. androgynus-induced bronchiolitis obliterans for providing new ideas to the mechanism of the disease and pharmacology research of the plant.

MATERIALS AND METHODS

The data presented in this review were collected from published literatures as well as the electronic databases of PubMed, CNKI, Web of Science, SCI finder, ACS, Science Direct, Wiley, Springer, Taylor, Google Scholar, and a number of unpublished resources, (e.g. books, and Ph.D. and M.Sc. dissertations).

RESULTS

The scientific literature indicates that S. androgynus is a valuable and popular herbal medicine whose nutritional value is also higher than that of other commonly used vegetables. Phytochemical analyses identified high content of fatty acids, flavonoids, and polyphenols as the major bioactive components in S. androgynus. Crude extracts and phytochemical compounds isolated from S. androgynus show a wide spectrum of in vitro and in vivo pharmacological activities such as antioxidant, anti-inflammatory, anti-ulcer, skin whitening, anti-diabetic, and immunoregulatory activities. The traditional use, such as increasing lactation, treating ulcers and diabetes, and reducing obesity, have been evaluated and studied with various methods. Numerous reports have revealed the unusual link between the consumption of S. androgynus and the induction of a chronic and irreversible obstructive disease (namely, bronchiolitis obliterans), indicating that the toxicity and side effects of this plant that is presently used in health care and medicine are a major area of concern.

CONCLUSION

Though little importance was attached to this green plant, S. androgynus has notable phytochemical constituents and various pharmacological activities including antioxidant, anti-inflammatory, and anti-obesity activities. Studies have firmly established the association between excessive consumption of the uncooked S. androgynus juice over a period of time and the occurrence of bronchiolitis obliterans. It is inadvisable to ingest excessive amounts of S. androgynus before fully understanding the pathogenesis and induction mechanism of this fatal disease. The phytochemistry of S. androgynus, its pharmacology for traditional use, S. androgynus-induced bronchiolitis obliterans still need further investigation.

Quantitative CT analysis for bronchiolitis obliterans in perinatally HIV-infected adolescents-comparison with controls and lung function data

OBJECTIVE

To compare quantitative chest CT parameters in perinatally HIV-infected adolescents with and without bronchiolitis obliterans compared with HIV-uninfected controls and their association with lung function measurements.

MATERIALS AND METHODS

Seventy-eight (41 girls) HIV-infected adolescents with a mean age of 13.8 ± 1.65 years and abnormal pulmonary function tests in the prospective Cape Town Adolescent Antiretroviral Cohort underwent contrast-enhanced chest CT on inspiration and expiration. Sixteen age-, sex-, and height-matched non-infected controls were identified retrospectively. Fifty-one HIV-infected adolescents (28 girls) displayed mosaic attenuation on expiration suggesting bronchiolitis obliterans. Pulmonary function tests were collected. The following parameters were obtained: low- and high-attenuation areas, mean lung density, kurtosis, skewness, ventilation heterogeneity, lung mass, and volume.

RESULTS

HIV-infected adolescents showed a significantly higher mean lung density, ventilation heterogeneity, mass, and high- and low-attenuation areas compared with non-infected individuals. Kurtosis and skewness were significantly lower as well. HIV-infected adolescents with bronchiolitis obliterans had a significantly lower kurtosis and skewness compared with those without bronchiolitis obliterans. Lung mass and volume showed the strongest correlations with forced expiratory volume in 1 s (FEV₁), forced vital capacity (FVC), and alveolar volume. Low-attenuation areas below - 950 HU and ventilation heterogeneity showed the strongest correlation with FEV₁/FVC (range, - 0.51 to - 0.34) and forced expiratory flow between 25 and 75% of FVC (range, - 0.50 to - 0.35).

CONCLUSION

Quantitative chest CT on inspiration is a feasible technique to differentiate perinatally HIV-infected adolescents with and without bronchiolitis obliterans. Quantitative CT parameters correlate with spirometric measurements of small-airway disease.

KEY POINTS

• Perinatally HIV-infected adolescents showed a more heterogeneous attenuation of the lung parenchyma with a higher percentage of low- and high-attenuation areas compared with non-infected patients. • Kurtosis and skewness are able to differentiate between HIV-infected adolescents with and without bronchiolitis obliterans using an inspiratory chest CT. • Quantitative CT parameters of the chest correlate significantly with pulmonary function test. Low-attenuation areas and ventilation heterogeneity are particularly associated with spirometric parameters related to airway obstruction.

[Clinical analysis of 30 cases of Castleman disease with different types of thoracic involvement]

目的

总结不同类型胸部受累Castleman病（CD）的临床、影像学、病理及诊治特征，以提高临床医师对CD的认识。

方法

回顾性分析广州医科大学附属第一医院自2009年6月至2019年5月收治入院的胸部受累CD患者30例，将其分为闭塞性细支气管炎（BO）组、不伴BO的单中心型Castleman病（UCD）组及不伴BO的多中心型Castleman病（MCD）组，分析其临床资料并总结其特征。

结果

30例患者中，5例（16.7%）纳入BO组，18例（60.0%）纳入不伴BO的UCD组，7例（23.3%）纳入不伴BO的MCD组。不伴BO的MCD组中位年龄明显大于BO组[（49.29±5.39）岁对（27.20±3.76）岁，P=0.005]和不伴BO的UCD组[（49.29±5.39）岁对（37.17±2.87）岁，P=0.034]。胸部症状在BO组（100%）和不伴BO的MCD组（71.4%）多见，而不伴BO的UCD组无胸部症状。贫血及IgG增高仅在不伴BO的MCD组出现（发生率均为57.1%），红细胞沉降率增快及低氧血症在BO组（发生率分别为40.0%和60.0%）及不伴BO的MCD组（发生率分别为57.1%和28.6%）均可出现。BO组患者的肺功能均表现为极重度混合性通气功能障碍。胸部CT所示肺实质受累率：BO组为100%；不伴BO的MCD组为57.1%，表现为双肺弥漫性病变；不伴BO的UCD组为11.1%，表现为孤立性肺结节。不伴BO的MCD组的淋巴结短径明显小于BO组[（1.83±0.51）cm对（4.73±1.63）cm，P=0.006]和不伴BO的UCD组[（1.83±0.51）cm对（3.62±0.26）cm，P=0.011]。BO组病理类型均为透明血管型（100%），不伴BO的UCD组88.9%为透明血管型，而不伴BO的MCD组以浆细胞型为主（57.1%）。BO组患者均出现口腔溃疡，在肿物切除术后予免疫调节剂治疗，溃疡症状缓解，但肺部症状仍进行性加重。不伴BO的UCD组主要治疗方式为胸腔镜下肿物切除，不伴BO的MCD组主要治疗方式为化疗、免疫调节剂、靶向治疗等。

结论

三组患者的年龄、临床症状、实验室检查、肺功能、影像学表现、病理类型、治疗及预后均有所不同，此分类能促进临床医师对本病的认识。

Bone Marrow-derived Mesenchymal Stem Cells and Chronic Allograft Disease in a Bronchiolitis Obliterans Animal Model

INTRODUCTION

Bronchiolitis obliterans (BO) is the most common expression of chronic allograft dysfunction in lung transplantation. Moreover, BO represents the major cause of death in the long-term after this procedure. On the other hand, mesenchymal stem cells have been tested in animal models of BO aiming to interfere in its development. The aim of this experimental study is to explore the role of bone-marrow derived stem cells (BMSCs) as a preventive intervention of BO occurrence.

MATERIALS AND METHODS

This an experimental randomized study. A bronchiolitis obliterans animal model in rats was reproduced: heterotopical tracheal transplant model in lung parenchyma. Five of these animals were used as control group. After setting up the model, individuals were divided in 3 groups of treatment (n=15), in which BMSCs were administered in 3 different time points after the tracheal transplant (tracheal transplantation and BMSCs administration occurred the same day, group G0; after 7 days, group G7; after 14 days, group G14. In addition, within each group, BMSCs were administered through 3 different routes: endotracheally, endovascular and topically in the lung parenchyma). Animals were sacrificed at 21 days. Histology, fluorescence in situ hybridization and immunohistochemistry techniques were performed for identifying stem cells.

RESULTS

Compared to control group, animals receiving BMSCs showed large neovessels in a loose fibrous matrix. Group G7 showed less fibrosis (p<0.033) and edema (p<0.028). Moreover, G7 animals receiving stem cells endotracheally showed no fibrosis (p<0.008). Alveolar-like patches of tissue were observed among all groups (53.4%, 46.7% and 40% in G0, G7 and G14 respectively), consisting of cells expressing both stem and alveolar cells biomarkers.

CONCLUSION

BMSCs modify the course of bronchiolitis obliterans and differentiate into alveolar cells. Endotracheal administration of BMSCs 7 days after the heterotopical tracheal transplant might be considered an effective way to prevent BO in this animal model.

Epithelial-mesenchymal transition and membrane microparticles: Potential implications for bronchiolitis obliterans syndrome after lung transplantation

Long term survival post lung transplantation (LTx) is limited by the occurrence of bronchiolitis obliterans syndrome (BOS). One mechanism involved is the epithelial-mesenchymal transition (EMT). Membrane microparticles (MPs) are known to be involved in some respiratory diseases and in other organs allograft rejection episodes. We hypothesized that leukocyte-derived MPs likely contribute to EMT. To emphasize this physiological concept, our objectives were to: (1) confirm the presence of EMT on explanted lungs from patients who underwent a second LTx for BOS; 2) characterize circulating MPs in transplanted patients, with or without BOS; (3) evaluate in vitro the effect of monocyte-derived MPs in EMT of human bronchial epithelial cells. Our IHC analysis on explanted graft lungs revealed significant pathological signs of EMT with an inhomogeneous destruction of the bronchial epithelium, with decreased expression of the epithelial protein E-cadherin and increased expression of the mesenchymal protein Vimentin. The immunophenotyping of MPs demonstrated that the concentration of MPs carrying E-cadherin was lower in patients affected by BOS (p = .007). In vitro, monocyte-derived MPs produced with LPS were associated with decreased E-cadherin expression (p < .05) along with significant morphological and functional cell modifications. MPs may play a role in EMT onset in bronchial epithelium following LTx.

Comprehensive pulmonary rehabilitation in patients with bronchiolitis obliterans syndrome: A case series

Chronic graft-versus-host disease (GVHD) is a significant complication of allogeneic hematopoietic stem cell transplantation, affecting 30%-70% of transplant recipients. One of the most challenging manifestations of chronic pulmonary GVHD is bronchiolitis obliterans syndrome (BOS), a rare and difficult-to-diagnose disease associated with a high mortality rate. BOS results in progressive circumferential fibrosis and, ultimately, cicatrization of the small terminal airways, manifesting as new fixed airflow obstruction. Although BOS patients are typically treated with immunosuppressive agents, there is no strong evidence that any specific therapies are effective in improving long-term outcomes. Thus, the mortality rate remains high. Therefore, there is an increasing need for additional therapies, including pulmonary rehabilitation (PR), in patients with BOS. PR is an evidence-based and comprehensive intervention for patients with chronic obstructive lung disease aimed at alleviating respiratory symptoms and optimizing functional capacity. This present case series demonstrates that comprehensive PR may also improve exercise tolerance and dyspnea in patients with BOS.

Lung evaluation in 10 year survivors of pediatric allogeneic hematopoietic stem cell transplantation

There is little data on the long-term respiratory development of children after allogeneic hematopoietic stem cell transplantation (allo-HSCT). We describe the respiratory assessment 10 years after allo-HSCT of 35 children transplanted between 2000 and 2004. During this period, 90 children were transplanted at our center. Twenty-five children died, thirty were lost to follow-up, and thirty-five came to have a pulmonary investigation. The thirty-five participants answered a questionnaire asking if they had pulmonary symptoms, and pulmonary function tests (PFTs) were performed. The median age of these children 10 years after the transplant was 16 years old. Just over a third of them had pulmonary symptoms. Among them, 5/13 (38%) had bronchiolitis obliterans syndrome (BOS). The majority of children (62.8%) did not have respiratory symptoms. PFTs were abnormal in one-third of asymptomatic children, revealing restrictive lung disease that was always mild to moderate (p = 0.02).Conclusion: In the long term, research at the time of the medical examination for the presence of chronic cough, shortness of breath on exertion, or wheezing helps to guide the clinician as to the need for further lung exploration. Similarly, informing patients and their families about these symptoms, which can be underestimated, should allow for more specific management.What is Known:• Pulmonary complications are a major cause of hematopoietic stem cell transplantation (HSCT) morbidity and mortality.• A long time after allogeneic HSCT, pulmonary function tests abnormalities may occur in children, but it is not always related to symptoms.What is New:• The occurrence of respiratory symptoms: cough, dyspnea on exertion, chronic bronchitis, and wheezing should be systematically investigated in the follow-up of allografted patients, even at a distance.• The presence of respiratory symptoms should lead to a respiratory functional investigation to detect the presence of an obstructive syndrome.

Azithromycin Use and Increased Cancer Risk among Patients with Bronchiolitis Obliterans after Hematopoietic Cell Transplantation

Azithromycin exposure during the early phase of allogeneic hematopoietic cell transplantation (HCT) has been associated with an increased incidence of hematologic relapse. We assessed the impact of azithromycin exposure on the occurrence of relapse or new subsequent neoplasm (SN) in patients with bronchiolitis obliterans syndrome (BOS) after HCT who are commonly treated with azithromycin alone or in combination with other agents. In a retrospective study of patients with BOS from 2 large allograft centers, the effect of azithromycin exposure on the risk of relapse or SN was estimated from a Cox model with a time-dependent variable for treatment initiation. The Cox model was adjusted on time-fixed covariates measured at cohort entry, selected for their potential prognostic value. Similar models were used to assess the exposure effect on the cause-specific hazard of relapse, SN, and death free of those events. Sensitivity analyses were performed using propensity score matching. Among 316 patients, 227 (71.8%) were exposed to azithromycin after BOS diagnosis. The corresponding adjusted hazard ratio (HR) in patients exposed to azithromycin versus unexposed was 1.51 (95% confidence interval [CI], 0.90 to 2.55) for relapse or SN, 0.82 (95% CI, 0.37 to 1.83) for relapse, and 2.00 (95% CI, 1.01 to 3.99) for SN. Patients exposed to azithromycin had a significantly lower cause-specific hazard of death free of neoplasm and relapse (adjusted HR, 0.54; 95% CI, 0.34 to 0.89). In conclusion, exposure to azithromycin after BOS after HCT was associated with an increased risk of SN but not relapse.

FK506 combined with GM6001 prevents tracheal obliteration in a mouse model of heterotopic tracheal transplantation

BACKGROUND

Obliterative bronchiolitis (OB) is the major complication limiting the long-term survival of allografts after lung transplantation. In this study, we investigated the effect of tacrolimus (FK506) combined with GM6001，a matrix metalloproteinase (MMP) inhibitor， on the formation of OB using a mouse heterotopic tracheal transplantation model.

METHODS

Syngeneic tracheal grafts were transplanted heterotopically from BALB/c mice to BALB/c mice. Allografts from C57BL/6 mice were transplanted to BALB/c mice. Isograft group, allograft group, allograft+FK506 group, allograft +GM6001 group and allograft+FK506 + GM6001 group was given respectively intraperitoneal injection of saline, saline, FK506, GM6001 and FK506 + GM6001 once a day. At 28 day after transplantation, OB incidence was determined by hematoxylin-eosin staining and the expressions of MMPs and cytokines were assessed using enzyme linked immunosorbent assay, immunohistochemical assays and western blot assay.

RESULTS

The tracheal occlusion rates of isograft group, allograft group, allograft+FK506 group, allograft+GM6001 group and allograft+FK506 + GM6001 group were 0, 74.1 ± 9.79%, 34.4 ± 6.04%, 40.3 ± 8.77% and 26.5 ± 5.73% respectively. There were significant differences between the latter two groups (P < .001). The serum MMP-8 and MMP-9 levels of allograft group were significantly higher than those of isograft group (P < .05) and had no significant decrease when treated by FK506. The serum MMP-8 and MMP-9 levels of allograft+FK506 + GM6001 group were significantly lower than those of allograft+FK506 group (P < .05). MMP-8 and MMP-9 protein expression in the grafts of allograft+FK506 + GM6001 group were lower than those of allograft+FK506 group verified by immunohistochemical staining and western blotting.

CONCLUSION

FK506 combined with GM6001 could alleviate tracheal obliteration in mouse heterotopic tracheal transplantation model, due to its inhibitory effect on MMPs.

[Successful lung transplantation after long-term ventilator and extracorporeal membrane oxygenation support in a patient with severe bronchiolitis obliterans following allogeneic bone marrow transplantation]

A 29-year-old man was diagnosed with acute myeloid leukemia at 20 years of age; he achieved a second complete remission at 22 years of age after an allogeneic unrelated bone marrow transplantation. After 14 months, he developed bronchiolitis obliterans (BO) due to chronic graft-versus-host disease. Home ventilator management was continuously performed for 3 years, but the patient required extracorporeal membrane oxygenation (ECMO) after progression to type 2 respiratory failure. A matched brain-dead lung donor was found after 5 months of intensive care management on ECMO, and bilateral lung transplantation was successfully performed. BO is a progressive refractory respiratory disease with poor prognosis. Careful management of infection, monitoring organ function, and lung transplantation at the appropriate time of initiation of mechanical ventilation or ECMO may save a patient's life. However, it is crucial to collaborate with higher education institutions or medical professionals in other departments.

Health-related quality of life in post-infectious bronchiolitis obliterans: agreement between children and their proxy

OBJECTIVE

To assess the level of agreement in health-related quality of life between children with Post-infectious Bronchiolitis Obliterans and their parent (so-called proxy).

METHODS

Participants aged between 8and 17 years who had been previously diagnosed with Post-infectious Bronchiolitis Obliterans were regularly followed up at a pediatric pulmonology outpatient clinic. Parents or legal guardians (caregivers) of these patients were also recruited for the study. A validated and age-appropriate version of the Pediatric Quality of Life Inventory 4.0 was used for the assessment of health-related quality of life. Caregivers completed the corresponding proxy versions of the questionnaire. The correlation between self and proxy reports of health-related quality of life was determined by intra-class correlation coefficient and dependent t-tests.

RESULTS

The majority of participants were males (79.4%), and the average age was 11.8 years. Intra-class correlations between each of the Pediatric Quality of Life Inventory 4.0 domains and the total score were all lower than 0.6, with a range between 0.267 (poor) and 0.530 (fair). When the means of each domain and the total score of the questionnaires were compared, caregivers were observed to have a significantly lower health-related quality of life score than children, with the exception of the social domain in which the difference was not significant. However, the differences in score exceeded the critical threshold difference of four points in all other domains.

CONCLUSION

Proxies of children and adolescents with Post-infectious Bronchiolitis Obliterans appear to consistently perceive their children as having lower health-related quality of life than how the patients perceive themselves.

Bronchoscopic features, associations, and outcomes of organizing pneumonia following allogeneic hematopoietic stem cell transplantation

Organizing pneumonia (OP) is a poorly understood complication of hematopoietic stem cell transplant (HSCT). We identified 15 patients diagnosed with OP following HSCT and described their clinical course. CT chest findings were remarkable for multifocal infiltrates that were predominantly consolidating or ground glass opacities. Bronchoalveolar lavage (BAL) was performed on 14 patients with five having lymphocytosis (> 25% lymphocytes), three with eosinophilia (> 5% eosinophils), three with neutrophilia (> 30% neutrophils), and three with normal cell counts. Flow cytometry was analyzed on BAL fluid in 13 patients with 11 having a CD4/CD8 of < 0.9. Initial treatment with 0.3–1.0 mg/kg prednisone resulted in improvement in symptoms, in radiographic findings, and in pulmonary function testing for the majority of patients. Six patients had recurrence of OP after completing treatment. Eleven patients had evidence of extra-pulmonary graft-versus-host disease prior to diagnosis of OP, and seven patients were diagnosed with an upper respiratory tract infection (URI) within 8 weeks of OP diagnosis. Most patients respond well to prednisone with significant improvement in pulmonary function, but risk of recurrence is high after cessation of steroid treatment. Risk factors for the development of OP may include prior URI.

Diagnosing and managing bronchiolitis obliterans in children

INTRODUCTION

Bronchiolitis obliterans (BO) is a chronic and irreversible obstructive lung disease leading to the obstruction and/or obliteration of the small airways. Three main BO entities are distinguished: post-infectious BO (PIBO); BO post lung transplantation; and BO after bone marrow transplantation (BMT) or hematopoietic stem cell transplantation (HSCT). All three entities are separate, however, there are similarities in histopathological characteristics and possibly in aspects of the development pathway. Areas covered: We review current evidence of bronchiolitis obliterans diagnosis and management in children. The diagnosis of BO is usually based on a combination of history, clinical and radiological findings, although lung biopsy and histopathology remain the gold standard approaches to confirm BO. Expert opinion: At present, we do not have a clear understanding of the mechanisms of the development of BO and lack strong evidence for treatment. Although most BO in children is post-infectious, most of the current evidence for treatment originates from studies analyzing BO in adult lung transplant and HSCT patients. BO management requires multidisciplinary approach and care in specialized centers.

The role of HIF-1α-VEGF pathway in bronchiolitis obliterans after lung transplantation

Background

Graft function may be affected if the organ is exposed to hypoxia. We hypothesized that bronchiolitis obliterans (BO) after lung transplantation is associated with hypoxia-inducible factor-1α (HIF-1α). This study compares the expression of HIF-1α and its downstream proteins in allograft and isograft to explore the relationship between this pathway and BO in rats.

Material and methods

We performed an orthotopic left pulmonary transplant model using the tri-cuff vascular anastomosis method and evaluated the histopathology, including the severity of fibrosis (SF). The expression of HIF-1α, VEGF-A, and VEGFR-2 was accessed by immunohistochemistry.

Results

The imageology and pathology showed that the allogenic model developed BO 90 days after the operation. The percentages of a high expression of HIF-1α, VEGF-A, and VEGFR-2 in the allogeneic group were 77.27, 63.64, and 68.18% higher than in the isogeneic group, respectively. The SF score was highest in the allograft and was positively correlated with the expression of the proteins.

Conclusion

This model can simulate human BO after lung transplantation. The expression of HIF-1α and its downstream proteins in post-transplantation was up-regulated, suggesting that activation of the HIF-1α-VEGF pathway might be involved in the occurrence and prognosis of BO.

[Follicular lymphoma accompanied by paraneoplastic pemphigus and bronchiolitis obliterans: a case report]

A 54-year-old female complained of oral erosion. A flaccid blister appeared on the trunk 2 months after the onset. The high titer of the anti-desmoglein 1 antibody in the absence of Nikolsky's sign led to the diagnosis of pemphigus vulgaris. The lymphadenopathy in the mesenteric and para-aortic regions indicated the possibility of paraneoplastic pemphigus. The steroid pulse therapy and therapeutic plasma exchange were ineffective. As CT-guided intraperitoneal lymph node biopsy revealed follicular lymphoma, R-CHOP therapy was performed. Although partial remission was attained accompanied by an improvement in the skin and mucosal findings after four courses of R-CHOP therapy, an occlusive ventilatory disturbance, possibly attributed to bronchiolitis obliterans, appeared 4 months after the treatment initiation. Although the treatment with tacrolimus was attempted, it was not feasible to be continued because of opportunistic infection, and the patient died 9 months after the onset of the skin lesion. Although specific anti-plakin antibodies were negative, this case was diagnosed as paraneoplastic pemphigus due to follicular lymphoma and complicated by obstructive bronchiolitis based on the clinical findings. The accumulation of similar cases is needed to establish effective treatment strategies.