A nonlinear relationship between visceral adipose tissue and frailty in adult lung transplant candidates.

Frailty is a state of decreased physiologic reserve associated with poor outcomes before and after lung transplantation. Obesity, particularly central obesity characterized by excess proinflammatory visceral adipose tissue (VAT), is associated with incident frailty in middle-aged and older adults. The association between VAT and frailty in advanced lung disease, however, is unknown. In two, nonoverlapping multicenter cohorts of adults listed for lung transplantation, we measured VAT area on bioelectrical impedance assay (BIA) in one cohort and cross-sectional VAT and subcutaneous adipose tissue (SAT) areas on abdominal computed tomography (CT) in the other. We identified a nonlinear relationship between greater VAT by BIA and frailty. In fully adjusted piecewise regression models, every 20 cm2 increase in VAT area was associated with 50% increased odds of frailty in subjects with high VAT (95% CI 1.2-1.9, P < .001), and 10% decreased odds of frailty (95% CI 0.7-1.04, P = .12) in subjects with low VAT. Compared to frail subjects with low VAT, those with high VAT were more likely to have low grip strength and less likely to have weight loss, suggesting that mechanisms of frailty may differ by VAT. Further investigation of mechanisms linking VAT and frailty may identify new targets for prevention and treatment.

A mobile health technology enabled home-based intervention to treat frailty in adult lung transplant candidates: A pilot study.

BACKGROUND: Frailty is prevalent in lung transplant candidates (LTC) and is associated with waitlist delisting or death. We performed a pilot study to assess the safety and feasibility of a home-based, mobile health technology-facilitated intervention to treat frailty in LTC. METHODS: We performed an 8-week, nonrandomized, home-based exercise and nutrition intervention in LTC with Short Physical Performance Battery (SPPB) frailty scores of ≤11. The intervention utilized a customized, mobile device application ("app") enabling monitoring and progression of the intervention in real time. We aimed to evaluate key process measures. Secondarily, we tested whether the intervention could improve frailty scores quantified by the SPPB and Fried Frailty Phenotype (FFP). RESULTS: A total of 15 subjects enrolled were 63 ± 5.7 years old; oxygen requirements ranged from 3 to 15LPM. Thirteen subjects completed the intervention. Over 108 subject-weeks, there were no adverse events. Subjects found the app engaging and easy to work with. SPPB frailty improved in 7 (54%) and FFP improved in 8 (62%). There was a strong trend toward improved frailty scores (SPPB change 1.0 ± 1.9; P = .08; FFP change -0.6 ± 1.0; P = .07). CONCLUSION: In this pilot study, we found that a home-based prehabilitation program that leverages mobile health technology to target frailty in LTC is well received, safe, and capable of improving physical frailty scores.

Lung Allograft Epithelium DNA Methylation Age Is Associated With Graft Chronologic Age and Primary Graft Dysfunction.

Advanced donor age is a risk factor for poor survival following lung transplantation. However, recent work identifying epigenetic determinants of aging has shown that biologic age may not always reflect chronologic age and that stressors can accelerate biologic aging. We hypothesized that lung allografts that experienced primary graft dysfunction (PGD), characterized by poor oxygenation in the first three post-transplant days, would have increased biologic age. We cultured airway epithelial cells isolated by transbronchial brush at 1-year bronchoscopies from 13 subjects with severe PGD and 15 controls matched on age and transplant indication. We measured epigenetic age using the Horvath epigenetic clock. Linear models were used to determine the association of airway epigenetic age with chronologic ages and PGD status, adjusted for recipient PGD risk factors. Survival models assessed the association with chronic lung allograft dysfunction (CLAD) or death. Distributions of promoter methylation within pathways were compared between groups. DNA methyltransferase (DNMT) activity was quantified in airway epithelial cells under hypoxic or normoxic conditions. Airway epigenetic age appeared younger but was strongly associated with the age of the allograft (slope 0.38 per year, 95% CI 0.27-0.48). There was no correlation between epigenetic age and recipient age (P = 0.96). Epigenetic age was 6.5 years greater (95% CI 1.7-11.2) in subjects who had experienced PGD, and this effect remained significant after adjusting for donor and recipient characteristics (P = 0.03). Epigenetic age was not associated with CLAD-free survival risk (P = 0.11). Analysis of differential methylation of promoters of key biologic pathways revealed hypomethylation in regions related to hypoxia, inflammation, and metabolism-associated pathways. Accordingly, airway epithelial cells cultured in hypoxic conditions showed suppressed DNMT activity. While airway methylation age was primarily determined by donor chronologic age, early injury in the form of PGD was associated with increased allograft epigenetic age. These data show how PGD might suppress key promoter methylation resulting in long-term impacts on the allograft.

Plasma Donor-derived Cell-free DNA Levels Are Increased During Acute Cellular Rejection After Lung Transplant: Pilot Data.

Telehealth platforms with remote phlebotomy and biomarker implementation represent a novel paradigm for surveillance after lung transplantation (LT). In a pilot study, we investigated donor-derived cell-free DNA (dd-cfDNA) in plasma using a clinical-grade "next-generation sequencing" assay. METHODS: dd-cfDNA levels determined in biorepository venous plasma samples obtained during the lung allograft rejection gene expression observation study, implementing a clinical-grade next-generation sequencing assay. Sixty-nine unique LT patients encompassing 9 LT centers, with associated clinical-histopathologic diagnoses, were examined-allograft infection (n = 26), normal histopathology without infection (n = 30), and acute cellular rejection (ACR; n = 13). RESULTS: dd-cfDNA in ACR patients were significantly elevated (1.52%; interquartile range [IQR], 0.520-2.2550) compared with the normal stable patients (0.485%; IQR, 0.220-0.790) (P = 0.026). During allograft infection, dd-cfDNA values were not different (0.595; IQR, 0.270-1.170) from normal (P = 0.282) and ACR (P = 0.100). AUC-receiver operator characteristics curve analysis for allograft ACR was 0.717 (95% confidence interval, 0.547-0.887; P = 0.025). At a 0.87% threshold dd-cfDNA-sensitivity = 73.1%, specificity = 52.9%, positive predictive value = 34.1%, and negative predictive value = 85.5%. CONCLUSIONS: dd-cfDNA assessment holds promise as a noninvasive biomarker of "allograft injury" with acute rejection following LT while prospective, multicenter studies should further refine utility across the spectrum of allograft rejection and infection.

Utility of fetal muscle biopsy for diagnosis of nemaline myopathy.

OBJECTIVES: To report and discuss prenatal diagnosis of nemaline myopathy (NM) using fetal muscle biopsy. METHODS: A consanguineous couple, with a history of a child with a clinical diagnosis of NM but no molecular genetic confirmation, was referred for prenatal diagnosis in two subsequent pregnancies. Fetal muscle biopsy with ultrasound guidance was undertaken at 22 and 21 weeks, respectively. RESULTS: Immunohistochemical and ultrastructural analysis of the fetal muscle specimen from the first 'at-risk' pregnancy was consistent with a diagnosis of NM and that pregnancy was terminated. Analysis of the fetal muscle specimen from the subsequent pregnancy revealed no pathologic abnormality. The pregnancy continued, and the child is unaffected. CONCLUSION: This represents the first reported prenatal diagnosis of NM by fetal muscle biopsy. Pathologic changes characteristic of NM can be identified in mid-second trimester fetal muscle.

Lung transplantation for hypersensitivity pneumonitis.

BACKGROUND: Hypersensitivity pneumonitis (HP) is an inhaled antigen-mediated interstitial lung disease (ILD). Advanced disease may necessitate the need for lung transplantation. There are no published studies addressing lung transplant outcomes in HP. We characterized HP outcomes compared with referents undergoing lung transplantation for idiopathic pulmonary fibrosis (IPF). METHODS: To identify HP cases, we reviewed records for all ILD lung transplantation cases at our institution from 2000 to 2013. We compared clinical characteristics, survival, and acute and chronic rejection for lung transplant recipients with HP to referents with IPF. We also reviewed diagnoses of HP discovered only by explant pathology and looked for evidence of recurrent HP after transplant. Survival was compared using Kaplan-Meier methods and Cox proportional hazard modeling. RESULTS: We analyzed 31 subjects with HP and 91 with IPF among 183 cases undergoing lung transplantation for ILD. Survival at 1, 3, and 5 years after lung transplant in HP compared with IPF was 96%, 89%, and 89% vs 86%, 67%, and 49%, respectively. Subjects with HP manifested a reduced adjusted risk for death compared with subjects with IPF (hazard ratio, 0.25; 95% CI, 0.08-0.74; P = .013). Of the 31 cases, the diagnosis of HP was unexpectedly made at explant in five (16%). Two subjects developed recurrent HP in their allografts. CONCLUSIONS: Overall, subjects with HP have excellent medium-term survival after lung transplantation and, relative to IPF, a reduced risk for death. HP may be initially discovered only by review of the explant pathology. Notably, HP may recur in the allograft.

Disorders of cortical development and epilepsy.

There has been an impressive increase in our ability to identify and categorize patients with cortical development lesions over the past decade. The clinical features associated with disorders of cortical development (DCD) have been described, and epilepsy has been shown to be a frequent symptom. In this review, we categorize DCD based on their structure and discuss their underlying causes and clinical features. Just as the cause of each type of disorder is thought to be unique, each disorder also has distinct types of seizures, treatment strategies, and electroencephalographic features. Studies in human tissue and animal models of DCD have begun to shed light on why DCD are associated with epilepsy. Aberrant synaptic connections within the dysplastic tissue and between the dysplastic tissue and more normal-appearing adjacent tissue form an abnormal, hyperexcitable network that increases seizure susceptibility. In the future, strategies for blocking formation of the aberrant networks may prevent the development of epilepsy.

Liquid chromatographic-tandem mass spectrometric assay for the simultaneous determination of didanosine and stavudine in human plasma, bronchoalveolar lavage fluid, alveolar cells, peripheral blood mononuclear cells, seminal plasma, cerebrospinal fluid and tonsil tissue.

We have developed a sensitive, high-pressure liquid chromatographic-tandem mass spectrometric (LC/MS/MS) method for the simultaneous determination of didanosine (ddI) and stavudine (d4T) in human plasma, bronchoalveolar lavage fluid (BALF), alveolar cells (AC), peripheral blood mononuclear cells (PBMC), seminal plasma, cerebrospinal fluid (CSF), and tonsil tissue. Plasma, AC, PBMC and CSF were run with an isocratic HPLC method, while BALF supernatant, semen, and tonsil tissue utilized a gradient elution. Samples were prepared by solid phase extraction. Detection was by electrospray positive ionization with multiple reaction monitoring mode. The lower limits of quantitation for both ddI and d4T were 2.0 ng/ml in plasma; 0.5 ng/ml in CSF; 0.4 ng/ml in AC, PBMC, and BALF; 1.0 ng/ml in seminal plasma; and 0.01 ng/mg in tonsil tissue.

The feasibility of lung transplantation in HIV-seropositive patients.

RATIONALE: HIV seropositivity has long been considered a contraindication to lung transplantation, primarily because of the potential risks of added immunosuppression. In the past decade, however, experience with kidney and liver transplantation in the setting of HIV infection, with achievement of satisfactory outcomes, has grown considerably. This promising development has created a need to reconsider this contraindication to lung transplantation. OBJECTIVES: There is presently limited evidence upon which to base medical decision-making regarding lung transplantation in individuals with HIV infection. In our present study, we wished to extend the existing literature by reporting the outcomes of three individuals with HIV infection who underwent lung transplantation at two centers. METHODS: We compiled data for a case series of three HIV-infected subjects undergoing lung transplantation at two centers. MEASUREMENTS AND MAIN RESULTS: We reviewed medical records to investigate the effects of lung transplantation on the course of HIV infection, the development of HIV-related opportunistic infections or malignancies, the occurrence of lung transplant and HIV drug interactions, and the extent of acute rejection. Subject 1, who underwent transplantation for HIV-associated pulmonary arterial hypertension, experienced recalcitrant acute rejection requiring a lymphocyte-depleting agent with subsequent rapid development of bronchiolitis obliterans syndrome. Subjects 2 and 3, who underwent transplantation for idiopathic pulmonary fibrosis, experienced mild acute rejection but remain free from chronic rejection at 4 and 2 years after transplant, respectively. CONCLUSIONS: Lung transplantation may be feasible for carefully selected patients in the setting of controlled HIV infection. On the basis of our experience with three patients, we caution that acute graft rejection may be more common in such patients.

mTOR cascade activation distinguishes tubers from focal cortical dysplasia.

Balloon cells (BCs) in focal cortical dysplasia (FCD) and giant cells (GCs) in tubers of the tuberous sclerosis complex (TSC) share phenotypic similarities. TSC1 or TSC2 gene mutations in TSC lead to mTOR pathway activation and p70S6kinase (phospho-S6K) and ribosomal S6 (phospho-S6) protein phosphorylation. Phospho-S6K, phospho-S6, and phospho-S6K-activated proteins phospho-STAT3 and phospho-4EBP1 were detected immunohistochemically in GCs, whereas only phospho-S6 was observed in BCs. Expression of four candidate gene families (cell signaling, cell adhesion, growth factor/receptor, and transcription factor mRNAs) was assayed in single, microdissected phospho-S6-immunolabeled BCs and GCs as a strategy to define whether BCs and GCs exhibit differential transcriptional profiles. Among 60 genes, differential expression of 24 mRNAs distinguished BCs from GCs and only 4 genes showed similar expression profiles between BCs and GCs. Tuberin mRNA levels were reduced in GCs from TSC patients with TSC2 gene mutations but were unchanged in BCs. Phospho-S6K, -S6, -STAT3, and -4EBP1 expression in GCs reflects loss of hamartin-tuberin-mediated mTOR pathway inhibition. Phospho-S6 expression alone in BCs does not support mTOR cascade activation in FCD. Differential gene expression profiles in BCs and GCs supports the hypothesis that these cell types derive by distinct pathogenic mechanisms.