Arlene A. Stecenko

Clinical Care Guidelines for Cystic Fibrosis–Related Diabetes: A position statement of the American Diabetes Association and a clinical practice guideline of the Cystic Fibrosis Foundation, endorsed by the Pediatric Endocrine Society

Cystic fibrosis–related diabetes (CFRD) is the most common comorbidity in people with cystic fibrosis (CF), occurring in ∼20% of adolescents and 40–50% of adults (1). While it shares features of type 1 and type 2 diabetes, CFRD is a distinct clinical entity. It is primarily caused by insulin insufficiency, although fluctuating levels of insulin resistance related to acute and chronic illness also play a role. The additional diagnosis of CFRD has a negative impact on pulmonary function and survival in CF, and this risk disproportionately affects women (2–4). In contrast to patients with other types of diabetes, there are no documented cases of death from atherosclerotic vascular disease in patients with CFRD, despite the fact that some now live into their sixth and seventh decades. These guidelines are the result of a joint effort between the Cystic Fibrosis Foundation (CFF), the American Diabetes Association (ADA), and the Pediatric Endocrine Society (PES). They are intended for use by CF patients, their care partners, and health care professionals and include recommendations for screening, diagnosis, and medical management of CFRD. This report focuses on aspects of care unique to CFRD. A comprehensive summary of recommendations for all people with diabetes can be found in the ADA Standards of Medical Care, published annually in the January supplement to Diabetes Care (5). In 2009, CFF in collaboration with ADA and PES convened a committee of CF and diabetes experts to update clinical care guidelines for CFRD. Investigators at Johns Hopkins University conducted evidence reviews on relevant clinical questions identified by the guidelines committee. The reviews were provided to the committee to use in developing recommendations. Where possible, the evidence for each recommendation was considered and graded by the committee using the ADA (5) and the U.S. Preventive Services Task Force (USPSTF) (6 …

Herpesvirus DNA Is Consistently Detected in Lungs of Patients with Idiopathic Pulmonary Fibrosis

ABSTRACT On the basis of earlier reports associating Epstein-Barr Virus (EBV) with half of the cases of idiopathic pulmonary fibrosis (IPF), we hypothesized that chronic infection with EBV or a closely related herpesvirus would be detected in all cases of IPF. We tested lung specimens from 33 IPF patients (8 patients with familial IPF and 25 patients with sporadic IPF) and 25 patients with other diseases as controls for the presence of eight herpesviruses using PCR-based techniques. One or more of four herpesviruses (cytomegalovirus [CMV], EBV, human herpesvirus 7 [HHV-7], and HHV-8) were detected in 32 of 33 (97%) subjects with IPF and in 9 of 25 (36%) controls (P < 0.0001). CMV, EBV, and HHV-8 were found more frequently in IPF patients than in controls (P < 0.05, P < 0.001, and P < 0.01 respectively). Two or more herpesviruses were detected in 19 of 33 (57%) IPF patients and in 2 of 25 (8%) controls (P < 0.001). Two or more herpesviruses and HHV-8 were found more frequently in patients with sporadic IPF than in patients with familial IPF (P < 0.05 for both comparisons), and CMV was found less frequently in patients with sporadic IPF than in patients with familial IPF (P < 0.05). Immunohistochemistry for EBV or HHV-8 antigen showed viral antigen primarily in airway epithelial cells. These data support the concept that a herpesvirus could be a source of chronic antigenic stimulation in IPF.

Twist: a regulator of epithelial-mesenchymal transition in lung fibrosis.

Background Several studies have implicated viral infection as an important factor in the pathogenesis of IPF and related fibrotic lung disorders. Viruses are thought to cause epithelial cell injury and promote epithelial-mesenchymal transition (EMT), a process whereby differentiated epithelial cells undergo transition to a mesenchymal phenotype, and considered a source of fibroblasts in the setting of lung injury. We have demonstrated an association between the epithelial injury caused by chronic herpes virus infection with the murine γ-herpes virus, MHV68, and lung fibrosis. We hypothesize that EMT in this model of virus-induced pulmonary fibrosis is driven by the expression of the transcription factor Twist. Methods/Findings In vitro MHV68 infection of murine lung epithelial cells induced expression of Twist, and mesenchymal markers. Stable overexpression of Twist promoted EMT in MLE15 lung epithelial cells. Transient knockdown expression of Twist resulted in preservation of epithelial phenotype after in vitro MHV68 infection. In concordance, high expression of Twist was found in lung epithelial cells of MHV68 infected mice, but not in mock infected mice. Alveolar epithelial cells from lung tissue of idiopathic pulmonary fibrosis (IPF) patients were strongly positive for Twist. These cells demonstrated features of EMT with low expression of E-cadherin and upregulation of the mesenchymal marker N-cadherin. Finally, IPF tissue with high Twist protein levels was also positive for the herpesvirus, EBV. Conclusions/Significance We conclude that Twist contributes to EMT in the model of virus-induced pulmonary fibrosis. We speculate that in some IPF cases, γ-herpes virus infection with EBV might be a source of injury precipitating EMT through the expression of Twist.

Treatment and Prevention of Vitamin D Insufficiency in Cystic Fibrosis Patients: Comparative Efficacy of Ergocalciferol, Cholecalciferol, and UV Light

BACKGROUND The optimal treatment for correcting or preventing vitamin D insufficiency in cystic fibrosis (CF) patients has not been established. OBJECTIVE The aim of the study was to assess the relative efficacy of three modes of vitamin D therapy: cholecalciferol (D3), ergocalciferol (D2), and UV light in raising or maintaining 25(OH)D levels above 30 ng/ml. DESIGN Thirty adult CF subjects with vitamin D insufficiency were randomized into one of three treatment arms: D3, D2, or UV light. Subjects randomized to D3 or D2 ingested 50,000 IU of vitamin D weekly, and those randomized to UV exposed their skin to UV light from a lamp five times a week. Serum was collected for 25(OH)D and PTH at baseline and at 12 wk. RESULTS Treatment with D3 and D2 raised 25(OH)D levels significantly, from a mean of 21.2 +/- 10.18 to 47.1 +/- 20.5 ng/ml (P < 0.001) and 24.4 +/- 10.3 to 32.7+/- 9.7 ng/ml (P = 0.01), with 100% and 60% reaching 25(OH)D levels above 30 ng/ml, respectively. Treatment with UV did not raise 25(OH)D levels significantly; however, only 55% of subjects were adherent with UV therapy. CONCLUSION This study demonstrates that CF subjects are able to achieve or maintain optimal vitamin D status (>30 ng/ml) with two oral regimens of either D3 or D2 treatment, the former being more efficacious. A confounding variable for this observation is the fact that the D3 and D2 capsules contained different carriers, powder-based vs. oil-based, respectively. UV therapy did not alter vitamin D status, possibly due to poor adherence to UV therapy.

Dysregulated Cytokine Production in Human Cystic Fibrosis Bronchial Epithelial Cells

Although pulmonary inflammation is an important pathologic event in cystic fibrosis (CF), the relationship between expression of the CF gene and the inflammatory response is unclear. We studied tumor necrosis factor (TNF) α and IL-1β stimulated production of IL-6 and IL-8 by CF, corrected CF, and normal human bronchial epithelial cells in culture. During the first 24 hours of TNFα stimulation, CF cells produced significantly more IL-8 than normal or corrected CF cells. In the second 24 hours of TNFα stimulation, IL-6 and IL-8 generation ceased in normal and corrected CF cells but accelerated in CF cells, resulting in marked IL-6 and IL-8 accumulation in CF cells. Similar results were found when cells were stimulated with IL-1β. Finally, when CF cells were grown at 27°C (a culture condition which results in transport of CF transmembrane conductance regulator, CFTR, to the cell membrane and normalization of chloride conductance) TNFα-stimulated production of IL-6 and IL-8 reverted to normal. We conclude that dysregulation of cytokine generation by CF bronchial epithelial cells is directly related to expression of mutant CFTR and these observations provide a potential mechanism for persistence of airway inflammation in CF.

Transfection of Nasal Mucosa with a Normal alpha1-Antitrypsin Gene in alpha1-Antitrypsin-Deficient Subjects: Comparison with Protein Therapy

We sought to determine whether a normal alpha1-antitrypsin (AAT) gene could be expressed in respiratory epithelium and whether local expression would have antiinflammatory effects. In an unblinded study, we delivered a normal AAT gene in a plasmid-cationic liposome complex to one nostril of each of five subjects with AAT deficiency; the other, untreated nostril served as a control. AAT protein concentration in nasal lavage fluid (NALF) increased in the transfected nostril (TN), but not in the control nostril (CN), of every subject, peaking on day 5 at levels about one-third normal (baseline CN, 4.1 +/- 1.2 microg/mg of protein; baseline TN, 4.3 +/- 1.3; day 5 CN, 4.0 +/- 0.5 [p = NS versus baseline]; day 5 TN, 9.0 +/- 1.7 [p < 0.5 versus baseline]); isoelectric focusing identified the transgene-generated protein (M) in the only two patients in whom the measurement was possible. The reverse transcriptase-polymerase chain reaction (RT-PCR), performed on NALF from TN and CN of four of the five subjects, was positive for transgene message in TN in all cases and negative in NALF from CN except for one time point in one subject. Interleukin 8 (IL-8) concentrations in NALF were elevated at baseline (normal [N = 10] = 2.5 +/- 0.5 ng/mg of protein; baseline TN = 5.5 +/- 0.8, p < 0.05 versus normal) and decreased after AAT transfection (TN = 2.9 +/- 0.6, p < 0.05 versus baseline) but not in the control nostril (CN = 6.5 +/- 2.2, p = NS versus baseline). NALF samples taken from four of the patients while receiving intravenous AAT protein showed normal concentrations of AAT, but IL-8 concentrations (10.5 +/- 4.2 ng/mg of protein, p = NS versus baseline) were not decreased from baseline. We conclude that plasmid-cationic liposome delivery of a normal AAT gene to the respiratory epithelium of deficient patients produces potentially therapeutic local AAT concentrations and that AAT gene therapy, unlike AAT protein therapy, is antiinflammatory.

Treatment of vitamin D deficiency with UV light in patients with malabsorption syndromes: a case series

Background: Cystic fibrosis (CF) and short bowel syndrome (SBS) patients are unable to absorb vitamin D from the diet and thus are frequently found to be severely vitamin D deficient. We evaluated whether a commercial portable ultraviolet (UV) indoor tanning lamp that has a spectral output that mimics natural sunlight could raise circulating 25‐hydroxyvitamin D [25(OH)D] levels in subjects with CF and SBS.

Pilot study of vitamin D supplementation in adults with cystic fibrosis pulmonary exacerbation: A randomized, controlled trial

Background: Vitamin D insufficiency is common in cystic fibrosis (CF) and vitamin D repletion may have an important role in improving clinical outcomes in CF. This randomized, placebo-controlled, pilot study examined the feasibility and impact of a single, large dose of cholecalciferol on vitamin D status and clinical outcomes in subjects with CF. Methods: Thirty adults with were randomized in a double-blinded, pilot study to receive 250,000 IU cholecalciferol or placebo within 48 h of hospital admission for a pulmonary exacerbation. Concentrations of 25-hydroxyvitamin D (25(OH)D), clinical outcomes and potential adverse events were assessed up to one year after randomization. Mixed effects linear regression models were used to evaluate the difference in mean serum concentrations and log-rank analyses were used to evaluate survival. Results: Data from all subjects was analyzed. Serum 25(OH)D concentrations increased from a mean of 30.6 ± 3.2 ng/mL to 58.1 ± 3.5 ng/mL (p < 0.001) at one week and 36.7 ± 2.6 ng/mL by 12 weeks (p = 0.06) in the vitamin D group; in contrast, serum 25(OH)D concentrations remained unchanged in the placebo group. Unadjusted, one-year survival and hospital-free days were increased in the vitamin D group (p = 0.029, p = 0.036; respectively). There was also a trend toward increased IV antibiotic therapy-free days in the vitamin D group (p = 0.073). There were no signs of hypervitaminosis D or adverse events. Serum PTH and calcium concentrations were similar across both groups. Conclusions: In this pilot study, a single, oral bolus of cholecalciferol increased serum 25(OH)D concentrations and was associated with a trend toward improved clinical outcomes in CF subjects hospitalized for a pulmonary exacerbation. Further investigation is needed into the clinical impact of improved vitamin D status in patients with CF.

Altered prostanoid production by fibroblasts cultured from the lungs of human subjects with idiopathic pulmonary fibrosis.

BackgroundProstanoids are known to participate in the process of fibrogenesis. Because lung fibroblasts produce prostanoids and are believed to play a central role in the pathogenesis of idiopathic pulmonary fibrosis (IPF), we hypothesized that fibroblasts (HF) cultured from the lungs of patients with IPF (HF-IPF) have an altered balance between profibrotic (thromboxane [TX]A2) and antifibrotic (prostacyclin [PGI2]) prostaglandins (PGs) when compared with normal human lung fibroblasts (HF-NL).MethodsWe measured inducible cyclooxygenase (COX)-2 gene and protein expression, and a profile of prostanoids at baseline and after IL-1β stimulation.ResultsIn both HF-IPF and HF-NL COX-2 expression was undetectable at baseline, but was significantly upregulated by IL-1β. PGE2 was the predominant COX product in IL-1β-stimulated cells with no significant difference between HF-IPF and HF-NL (28.35 [9.09–89.09] vs. 17.12 [8.58–29.33] ng/106 cells/30 min, respectively; P = 0.25). TXB2 (the stable metabolite of TXA2) production was significantly higher in IL-1β-stimulated HF-IPF compared to HF-NL (1.92 [1.27–2.57] vs. 0.61 [0.21–1.64] ng/106 cells/30 min, respectively; P = 0.007) and the ratio of PGI2 (as measured by its stable metabolite 6-keto-PGF1α) to TXB2 was significantly lower at baseline in HF-IPF (0.08 [0.04–0.52] vs. 0.12 [0.11–0.89] in HF-NL; P = 0.028) and with IL-1β stimulation (0.24 [0.05–1.53] vs. 1.08 [0.51–3.79] in HF-NL; P = 0.09).ConclusionAn alteration in the balance of profibrotic and antifibrotic PGs in HF-IPF may play a role in the pathogeneses of IPF.

Update on cystic fibrosis-related diabetes

Purpose of review The aim is to provide a detailed review of recent publications on cystic fibrosis-related diabetes (CFRD) with a particular focus on the interplay between cystic fibrosis (CF) lung disease and diabetes. Recent findings CFRD is a form of diabetes that is distinct from type 1 or type 2 diabetes. CFRD remains very common and increases in prevalence with increasing age so that one in two middle-aged CF persons have CFRD. People with CFRD have lower lung function, worse nutrition, more frequent hospitalization, and worse mortality than CF people without diabetes. The excess mortality previously noted in women with CFRD compared with CF women without diabetes or CF men is much less apparent. CFRD is due to insulin deficiency and peripheral insulin resistance is much less a factor. Genetic susceptibility and oxidant stress are key risk factors for developing CFRD. The lung is the prime end organ target in CFRD and mortality is due to respiratory failure, not vascular complications. Insulin is the mainstay of therapy and early recognition and institution of therapy appear to improve health outcomes. Summary CFRD remains one of the most important co-morbidities in CF. Early recognition of the disease and therapeutic intervention may diminish the negative impact that diabetes has on lung health in CF. Although a clearer understanding of the role of oxidant stress and genetics in the pathogenesis of CFRD is being elucidated, much needs to be learned before more targeted, specific therapies can be developed for this distinct form of diabetes.