Gaps in Cystic Fibrosis Care Are Associated with Reduced Lung Function in the U.S. Cystic Fibrosis Foundation Patient Registry

Rationale: Cystic fibrosis (CF) is a genetic disease leading to progressive lung function loss and early mortality. Many clinical and demographic variables are associated with lung function decline, but little is known about the effects of prolonged periods of missed care. Objectives: To determine if missed care in the Cystic Fibrosis Foundation Patient Registry (CFFPR) is associated with decreased lung function at follow-up visits. Methods: Deidentified CFFPR data for 2004-2016 were analyzed, with the exposure of interest being ⩾12-month gap in CFFPR data. We modeled percentage predicted forced expiratory volume in 1 second using longitudinal semiparametric modeling with natural cubic splines for age (knots at quantiles) and with subject-specific random effects, adjusted for sex and CFTR (cystic fibrosis transmembrane conductance regulator) genotype, race, and ethnicity and included time-varying covariates for gaps in care, insurance type, underweight body mass index, CF-related diabetes status, and chronic infections. Results: A total of 24,328 individuals with 1,082,899 encounters in the CFFPR met inclusion criteria. In the cohort, 8,413 (35%) individuals had at least a single ⩾12-month episode of discontinuity, whereas 15,915 (65%) had continuous care. Of the encounters preceded by a 12-month gap, 75.8% occurred in patients 18 years and older. Compared with those with continuous care, those with a discontinuous care episode had a lower follow-up percentage predicted forced expiratory volume in 1 second at the index visit (-0.81%; 95% confidence interval, -1.00, -0.61) after adjustment for other variables. The magnitude of this difference was much greater (-2.1%; 95% confidence interval, -1.5, -2.7) in young adult F508del homozygotes. Conclusions: There was a high rate of ⩾12-month gap in care, especially in adults, documented in the CFFPR. Discontinuous care identified in the CFFPR was strongly associated with decreased lung function, especially in adolescents and young adults homozygous for the F508del CFTR mutation. This may have implications for identifying and treating people with lengthy gaps in care and may have implications for CFF care recommendations.

Chronic Joint Pain in a Young Adult With Cystic Fibrosis

A 25-year-old male with end-stage cystic fibrosis (CF) with genotype F508del/F508del presented to the clinic complaining of bilateral knee and ankle pain. He had severe lung disease (forced expiratory volume 1 {FEV1} 19% of predicted), chronic colonization with achromobacter, malnutrition, and CF-related diabetes. On physical examination, he was found to have bilateral knee swelling as well as pain on flexion and extension of the wrists and ankles without erythema or warmth. He was empirically started on prednisone and tramadol; however, at a three-month follow-up visit, he remained symptomatic. He was sent for a whole-body bone scan, which was consistent with hypertrophic pulmonary osteoarthropathy (HPOA). He was started on highly effective modulator therapy with elexacaftor/tezacaftor/ivacaftor and symptoms spontaneously resolved without further intervention.

Use of ceftolozane-tazobactam in a cystic fibrosis patient with multidrug-resistant pseudomonas infection and renal insufficiency

We report the successful use of ceftolozane/tazobactam (C/T) to treat a pulmonary exacerbation in a 35 year old female, post lung transplant, with cystic fibrosis (CF), malnutrition, chronic kidney disease, and multi-drug resistant Pseudomonas aeruginosa infection (MDR PSA). Given the complexity of the clinical profile, we measured drug levels of C/T during treatment of her current exacerbation to determine pharmacokinetics. The patient achieved an estimated ceftolozane peak of 174.1 μg/mL and trough of 9.2 μg/mL. Serum half-life was found to be slightly shorter than previously reported in normal subjects, (2.3 hr. vs. 2.6 hr.) despite the presence of renal insufficiency. Treatment resulted in improvement in serum inflammatory markers and symptoms and was well-tolerated.

Lung-derived exosome uptake into and epigenetic modulation of marrow progenitor/stem and differentiated cells

Background

Our group has previously demonstrated that murine whole bone marrow cells (WBM) that internalize lung-derived extracellular vesicles (LDEVs) in culture express pulmonary epithelial cell–specific genes for up to 12 weeks. In addition, the lungs of lethally irradiated mice transplanted with lung vesicle–modulated marrow have 5 times more WBM-derived type II pneumocytes compared to mice transplanted with unmanipulated WBM. These findings indicate that extracellular vesicle modification may be an important consideration in the development of marrow cell–based cellular therapies. Current studies were performed to determine the specific marrow cell types that LDEV stably modify.

Methods

Murine WBM-derived stem/progenitor cells (Lin-/Sca-1+) and differentiated erythroid cells (Ter119+), granulocytes (Gr-1+) and B cells (CD19+) were cultured with carboxyfluorescein N-succinimidyl ester (CFSE)-labelled LDEV. LDEV+ cells (CFSE+) and LDEV− cells (CFSE−) were separated by flow cytometry and visualized by fluorescence microscopy, analyzed by RT-PCR or placed into long-term secondary culture. In addition, murine Lin-/Sca-1+ cells were cultured with CFSE-labelled LDEV isolated from rats, and RT-PCR analysis was performed on LDEV+ and – cells using species-specific primers for surfactant (rat/mouse hybrid co-cultures).

Results

Stem/progenitor cells and all of the differentiated cell types studied internalized LDEV in culture, but heterogeneously. Expression of a panel of pulmonary epithelial cell genes was higher in LDEV+cells compared to LDEV − cells and elevated expression of these genes persisted in long-term culture. Rat/mouse hybrid co-cultures revealed only mouse-specific surfactant B and C expression in LDEV+ Lin-/Sca-1+cells after 4 weeks of culture, indicating stable de novo gene expression.

Conclusions

LDEV can be internalized by differentiated and more primitive cells residing in the bone marrow in culture and can induce stable de novo pulmonary epithelial cell gene expression in these cells for several weeks after internalization. The gene expression represents a transcriptional activation of the target marrow cells. These studies serve as the basis for determining marrow cell types that can be used for cell-based therapies for processes that injure the pulmonary epithelial surfaces.

Partial anomalous pulmonary venous return presenting with adult-onset pulmonary hypertension

Partial anomalous pulmonary venous return (PAPVR) is a rare cause of adult onset pulmonary arterial hypertension (PAH) that can present with a wide spectrum of severity from early childhood throughout adult life. We present two patients with PAH secondary to PAPVR who reflect this range of disease. The diagnosis and treatment of PAPVR and its role in pulmonary vascular disease is discussed. Cardiac and pulmonary physicians should be aware of this entity and its diagnosis and management options.

Stable cell fate changes in marrow cells induced by lung-derived microvesicles

BACKGROUND

Interest has been generated in the capacity of cellular-derived microvesicles to alter the fate of different target cells. Lung, liver, heart and brain-derived vesicles can alter the genetic phenotype of murine marrow cells; however, the stability of such changes and the mechanism of these changes remain unclear. In the present work, we show that lung-derived microvesicles (LDMV) alter the transcriptome and proteome of target marrow cells initially by mRNA and regulator(s) of transcription transfer, but that long term phenotype change is due solely to transfer of a transcriptional regulator with target cell.

METHODS/RESULTS

IN VIVO STUDIES

Whole bone marrow cells (WBM) were co-cultured with LDMV (both isolated from male C57BL/6 mice) or cultured alone (control). One week later, cultured WBM was transplanted into lethally-irradiated female C57BL/6 mice. Recipient mice were sacrificed 6 weeks later and WBM, spleens and livers were examined for the presence of lung-specific gene expression, including surfactants A, B, C and D, aquaporin-5, and clara cell specific protein, via real-time RT-PCR. Immunohistochemistry was also performed on lungs to determine the number of transplanted marrow-derived (Y chromosome+) type II pneumocytes (prosurfactant C+). Mice transplanted with LDMV co-cultured WBM expressed pulmonary epithelial cell genes in the cells of their bone marrow, livers and spleens and over fivefold more transplanted marrow-derived Y+/prosurfactant C+cells could be found in their lungs (vs. control mice).

IN VITRO STUDIES

WBM (from mice or rats) was cultured with or without LDMV (from mice or rats) for 1 week then washed and cultured alone. WBM was harvested at 2-week intervals for real-time RT-PCR analysis, using species-specific surfactant primers, and for Western Blot analysis. Proteomic and microRNA microarray analyses were also performed on cells. LDMV co-cultured WBM maintained expression of pulmonary epithelial cell genes and proteins for up to 12 weeks in culture. Surfactant produced at later time points was specific only to the species of the marrow cell in culture indicating de novo mRNA transcription. These findings, in addition to the altered protein and microRNA profiles of LDMV co-cultured WBM, support a stable transcriptional mechanism for these changes.

CONCLUSIONS

These data indicate that microvesicle alteration of cell fate is robust and long-term and represents an important new aspect of cellular biology.

Progenitor/stem cell fate determination: interactive dynamics of cell cycle and microvesicles

We have shown that hematopoietic stem/progenitor cell phenotype and differentiative potential change throughout cell cycle. Lung-derived microvesicles (LDMVs) also change marrow cell phenotype by inducing them to express pulmonary epithelial cell-specific mRNA and protein. These changes are accentuated when microvesicles isolated from injured lung. We wish to determine if microvesicle-treated stem/progenitor cell phenotype is linked to cell cycle and to the injury status of the lung providing microvesicles. Lineage depleted, Sca-1+ (Lin-/Sca-1+) marrow isolated from mice were cultured with interleukin 3 (IL-3), IL-6, IL-11, and stem cell factor (cytokine-cultured cells), removed at hours zero (cell cycle phase G0/G1), 24 (late G1/early S), and 48 (late S/early G2/M), and cocultured with lung tissue, lung conditioned media (LCM), or LDMV from irradiated or nonirradiated mice. Alternatively, Lin-/Sca-1+ cells not exposed to exogenous cytokines were separated into G0/G1 and S/G2/M cell cycle phase populations by fluorescence-activated cell sorting (FACS) and used in coculture. Separately, LDMV from irradiated and nonirradiated mice were analyzed for the presence of adhesion proteins. Peak pulmonary epithelial cell-specific mRNA expression was seen in G0/G1 cytokine-cultured cells cocultured with irradiated lung and in late G1/early S cells cocultured with nonirradiated lung. The same pattern was seen in cytokine-cultured Lin-/Sca-1 cells cocultured with LCM and LDMV and when FACS-separated Lin-/Sca-1 cells unexposed to exogenous cytokines were used in coculture. Cells and LDMV expressed adhesion proteins whose levels differed based on cycle status (cells) or radiation injury (LDMV), suggesting a mechanism for microvesicle entry. These data demonstrate that microvesicle modification of progenitor/stem cells is influenced by cell cycle and the treatment of the originator lung tissue.

Marrow cell genetic phenotype change induced by human lung cancer cells

Microvesicles have been shown to mediate varieties of intercellular communication. Work in murine species has shown that lung-derived microvesicles can deliver mRNA, transcription factors, and microRNA to marrow cells and alter their phenotype. The present studies evaluated the capacity of excised human lung cancer cells to change the genetic phenotype of human marrow cells. We present the first studies on microvesicle production by excised cancers from human lung and the capacity of these microvesicles to alter the genetic phenotype of normal human marrow cells. We studied 12 cancers involving the lung and assessed nine lung-specific mRNA species (aquaporin, surfactant families, and clara cell-specific protein) in marrow cells exposed to tissue in co-culture, cultured in conditioned media, or exposed to isolated lung cancer-derived microvesicles. We assessed two or seven days of co-culture and marrow which was unseparated, separated by ficoll density gradient centrifugation or ammonium chloride lysis. Under these varying conditions, each cancer derived from lung mediated marrow expression of between one and seven lung-specific genes. Microvesicles were identified in the pellet of ultracentrifuged conditioned media and shown to enter marrow cells and induce lung-specific mRNA expression in marrow. A lung melanoma and a sarcoma also induced lung-specific mRNA in marrow cells. These data indicate that lung cancer cells may alter the genetic phenotype of normal cells and suggest that such perturbations might play a role in tumor progression, tumor recurrence, or metastases. They also suggest that the tissue environment may alter cancer cell gene expression.

Treatment options for cystic fibrosis: state of the art and future perspectives

Cystic fibrosis (CF) is an autosomal recessive disorder characterized by chronic lung and sinus disease, impaired mucociliary clearance (leading to recurrent pulmonary infection), pancreatic insufficiency, elevated sweat chloride levels and male infertility. Cystic fibrosis transmembrane conductance regulator (CFTR) is a cAMP-regulated chloride channel in the plasma membrane of epithelial cells lining the lung, pancreas, liver, intestines, sweat duct, and the epididymis. Genetic mutations in CFTR affect its synthesis, processing, and transport to the plasma membrane and/or impede its function as a chloride channel and conductance regulator. Research is proceeding on multiple fronts including inhalational agents, anti-inflammatory treatments, and pancreatic replacement therapies. Furthermore, improved understanding of the molecular mechanisms that lead to CFTR dysfunction has stimulated the design of therapeutic strategies aimed at restoration of CFTR function, or "protein repair therapy". Recent clinical trials have shown these interventions have the ability to restore some level of CFTR function in vivo. This review will provide an overview of recent clinical trials that investigate new therapeutic approaches in CF designed to treat chronic respiratory infection, reduce inflammation, and improve pancreatic enzyme supplementation as well as trials addressing the greatest therapeutic challenge--restoring the function of the CFTR protein.

The role of natriuretic peptides in inflammation and immunity

The natriuretic peptides (NPs) are a family of widely distributed, but evolutionarily conserved, polypeptide mediators that exert a range of effects throughout the body. There is growing realization that NP actions go far beyond volume and blood pressure homeostasis. Their pleiotropic effects include a significant role in regulating the immune system. Localization of NP receptors in various immune organs as well as in modulation of inflammation in vascular disease supports this hypothesis. Immune cells, including macrophages, dendritic cells, and T lymphocytes, express receptors for NPs. NPs are also involved in polarizing the immune response to allergens. NPs play an important role in shaping the early immune response to environmental antigens and appear to play a critical role in the interaction between cells of the innate and adaptive immune systems. The recent explosion of basic and clinical research has resulted in improved understanding of their molecular structure. This has facilitated development of chimeric forms of NPs as well as more convenient routes of administration. Thus, the NPs and their receptors could be exploited to develop therapeutics for the inflammatory and immune responses in wide range of diseases. Also discussed are several patents regarding NPs in the present review.