Predisposing factors for adrenal crisis in chronic adrenal insufficiency: a case-control study.

OBJECTIVE: This study aims to identify susceptibility markers for adrenal crises (AC) in educated patients with chronic adrenal insufficiency (AI). DESIGN: A case-control study involving 66 patients with AI analyzing the impact of glucocorticoid and mineralocorticoid exposure, adrenomedullary function, inflammatory parameters, and educational status on AC frequency. Patients were categorized into low (n = 32) and high (n = 34) AC frequency groups based on AC occurrence (below or 2 times above the average of the reported AC frequency of 8.3 AC/100 patient-years in a previous prospective study). METHODS: Parameters, including cortisol plasma profile and urinary steroid excretion after administration of the morning glucocorticoid dose, 24-h urinary steroid profiling, salivary cortisol profiling, and hair cortisol, estimated cortisol exposure. Polymorphisms (single nucleotide polymorphism [SNP]) of the glucocorticoid receptor (NR3C1) and mineralocorticoid receptor (NR3C2) associated with individual steroid sensitivity were assessed together with SNPs for 11ß-hydroxysteroid dehydrogenase 1 (HSD11B1) and 11ß-hydroxysteroid dehydrogenase 2 (HSD11B2). Mineralocorticoid replacement was evaluated by serum and urinary electrolytes and osmolality, plasma-renin concentration, and ambulatory blood pressure levels. We additionally measured plasma and urinary catecholamines, serum levels of IL6 and hsCRP, and SNPs of IL6 and TNF-alpha. Patient knowledge of AC prevention was assessed by questionnaires. RESULTS: Frequent AC patients had higher daily glucocorticoid doses and hair cortisol levels, with no significant differences in other parameters investigated. AC frequency is inversely correlated with the frequency of self-reported adjustments of the glucocorticoid replacement. CONCLUSION: Higher glucocorticoid dosages in high-risk patients, despite unaffected cortisol metabolism, may be linked to decreased cortisol sensitivity or impaired glucocorticoid absorption. Proactive dose adjustments show a protective effect against AC, regardless of biological vulnerability.

Improved Outcomes for Infants and Young Children Undergoing Lung Transplantation at Three Years of Age and Younger.

Rationale: Since its inception, older children and adolescents have predominated in pediatric lung transplantation. Most pediatric lung transplant programs around the world have transplanted few infants and young children. Early mortality after lung transplantation and inadequate donor organs have been perceived as limitations for success in lung transplantation at this age. Objectives: Our aim was to describe our experience in a large pediatric lung transplant program with respect to lung transplantation in infants and young children, focusing on diagnosis, waitlist, and mortality. Methods: We performed a retrospective review of infants and young children under 3 years of age at the time of transplant in our program from 2002 through 2020. Results: The patient cohort represented a severely morbid recipient group, with the majority hospitalized in the intensive care unit on mechanical ventilation just before transplantation. There was a marked heterogeneity of diagnoses distinct from diagnoses in an older cohort. Waitlist time was shorter than in older age cohorts. There was a decrease in early mortality, lower incidence of allograft rejection, and satisfactory long-term survival in this age group compared with the older cohort and published experience. Severe viral infection was an important cause of early mortality after transplant. Nonetheless, survival is comparable to older patients, with better enduring survival in those who survive the early transplant period in more recent years. Conclusions: Carefully selected infants and young children with end-stage lung and pulmonary vascular disease are appropriate candidates for lung transplantation and are likely underserved by current clinical practice.

Diagnosis and treatment of cryptococcal osteomyelitis in a pediatric lung transplant patient.

BACKGROUND: Asymptomatic pulmonary nodules may appear at any point after lung transplantation. The differential diagnosis is broad and includes serious life-threatening disease entities. METHODS: A retrospective case report of a single patient who developed a pulmonary nodule after lung transplantation. RESULTS: At 2 years post-transplant, an 11-year-old with cystic fibrosis was asymptomatic and had normal lung function. A single nodule was noted on surveillance chest CT scan. Initial evaluation was negative, but subsequently, he was diagnosed with cryptococcal osteomyelitis in a thoracic rib. He responded well to an extended course of antifungal therapy without loss of allograft function or infectious complications. CONCLUSION: Pulmonary nodules after lung transplantation may be a harbinger of serious complications. A systematic approach to evaluation and follow-up is recommended.

Impact of immunosuppressive therapy on brain derived cytokines after liver transplantation.

BACKGROUND: While acute neurotoxic side effects of calcineurin inhibitors (CNI) are well-known, data upon long-term effects on brain structure and function are sparse. We hypothesize that long-term CNI therapy affects the neuroimmune system, thereby, increasing the risk of neurodegeneration. Here, we measured the impact of CNI therapy on plasma levels of brain- and T cell-derived cytokines in a cohort of patients after liver transplantation (LT). METHODS: Levels of T cell-mediated cytokines (e.g. Interferon-γ (IFN-γ)) and brain-derived cytokines (e.g. brain derived neurotrophic factor (BDNF), platelet derived growth factor (PDGF)) were measured by multiplex assays in plasma of 82 patients about 10 years after LT (17 with CNI free, 35 with CNI low dose, 30 with standard dose CNI immunosuppression) and 33 healthy controls. Data were related to psychometric test results and parameters of cerebral magnetic resonance imaging. RESULTS: IFN-γ levels were significantly higher in the CNI free LT patient group (p=0.027) compared to healthy controls. BDNF levels were significantly lower in LT patients treated with CNI (CNI low: p<0.001; CNI standard: p=0.016) compared to controls. PDGF levels were significantly lower in the CNI low dose group (p=0.004) and for PDGF-AB/BB also in the CNI standard dose group (p=0.029) compared to controls. BDNF and PDGF negatively correlated with cognitive function and brain volume (p<0.05) in the CNI low dose group. CONCLUSION: Our results imply that long-term treatment with CNI suppresses BDNF and PDGF expression, both crucial for neuronal signaling, cell survival and synaptic plasticity and thereby may lead to cognitive dysfunction and neurodegeneration.

Longterm calcineurin inhibitor therapy and brain function in patients after liver transplantation.

Calcineurin inhibitors (CNIs) frequently induce neurological complications early after orthotopic liver transplantation (OLT). We hypothesize that longterm CNI therapy after OLT causes dose-dependent cognitive dysfunction and alteration of brain structure. In this study, 85 OLT patients (20 with CNI-free, 35 with CNI low-dose, and 30 with standard-dose CNI immunosuppression) underwent psychometric testing and cerebral magnetic resonance imaging approximately 10 years after OLT to assess brain function and structural brain alterations. A total of 33 healthy patients adjusted for age, sex, and education served as controls. Patients receiving CNI showed a significantly worse visuospatial/constructional ability compared with controls (P ≤ 0.04). Furthermore, patients on low-dose CNI therapy had an overall impaired cognitive function compared with controls (P = 0.01). The tacrolimus total dose and mean trough level were negatively correlated to cognitive function. CNI doses had been adjusted in 91% of the patients in the low-dose and CNI-free groups in the past due to CNI-induced kidney damage. Patients treated with CNI showed significantly more white matter hyperintensities (WMH) than patients on CNI-free immunosuppression and controls (P < 0.05). Both the mean cyclosporine A and tacrolimus trough levels correlated significantly with WMH. In conclusion, longterm CNI therapy carries a risk of cognitive dysfunction especially in patients who already showed nephrotoxic side effects indicating an increased susceptibility of these patients against toxic CNI effects. This subgroup of patients might benefit from a change to CNI-free immunosuppression. Liver Transplantation 24 56-66 2018 AASLD.

Characterization of Dnmt1 Binding and DNA Methylation on Nucleosomes and Nucleosomal Arrays.

The packaging of DNA into nucleosomes and the organisation into higher order structures of chromatin limits the access of sequence specific DNA binding factors to DNA. In cells, DNA methylation is preferentially occuring in the linker region of nucleosomes, suggesting a structural impact of chromatin on DNA methylation. These observations raise the question whether DNA methyltransferases are capable to recognize the nucleosomal substrates and to modify the packaged DNA. Here, we performed a detailed analysis of nucleosome binding and nucleosomal DNA methylation by the maintenance DNA methyltransferase Dnmt1. Our binding studies show that Dnmt1 has a DNA length sensing activity, binding cooperatively to DNA, and requiring a minimal DNA length of 20 bp. Dnmt1 needs linker DNA to bind to nucleosomes and most efficiently recognizes nucleosomes with symmetric DNA linkers. Footprinting experiments reveal that Dnmt1 binds to both DNA linkers exiting the nucleosome core. The binding pattern correlates with the efficient methylation of DNA linkers. However, the enzyme lacks the ability to methylate nucleosomal CpG sites on mononucleosomes and nucleosomal arrays, unless chromatin remodeling enzymes create a dynamic chromatin state. In addition, our results show that Dnmt1 functionally interacts with specific chromatin remodeling enzymes to enable complete methylation of hemi-methylated DNA in chromatin.

DNA sequence- and conformation-directed positioning of nucleosomes by chromatin-remodeling complexes.

Chromatin-remodeling complexes can translocate nucleosomes along the DNA in an ATP-coupled reaction. This process is an important regulator of all DNA-dependent processes because it determines whether certain DNA sequences are found in regions between nucleosomes with increased accessibility for other factors or wrapped around the histone octamer complex. In a comparison of seven different chromatin-remodeling machines (ACF, ISWI, Snf2H, Chd1, Mi-2, Brg1, and NURF), it is demonstrated that these complexes can read out DNA sequence features to establish specific nucleosome-positioning patterns. For one of the remodelers, ACF, we identified a 40-bp DNA sequence element that directs nucleosome positioning. Furthermore, we show that nucleosome positioning by the remodelers ACF and Chd1 is determined by a reduced affinity to the end product of the translocation reaction. The results suggest that the linkage of differential remodeling activities with the intrinsic binding preferences of nucleosomes can result in establishing distinct chromatin structures that depend on the DNA sequence and define the DNA accessibility for other protein factors.