Lymphangioleiomyomatosis: circulating levels of FGF23 and pulmonary diffusion.

OBJECTIVE: Lymphangioleiomyomatosis (LAM) is a rare, destructive disease of the lungs with a limited number of determinants of disease activity, which are a critical need for clinical trials. FGF23 has been implicated in several chronic pulmonary diseases. We aimed to determine the association between serum FGF23 levels and pulmonary function in a cohort of patients with LAM. METHODS: This was a descriptive single-center study in which subjects with LAM and controls with unreported lung disease were recruited. Serum FGF23 levels were measured in all subjects. Clinical data, including pulmonary function testing, were retrospectively obtained from electronic medical records of LAM subjects. Associations between FGF23 levels and clinical features of LAM were explored via nonparametric hypothesis testing. RESULTS: The sample comprised 37 subjects with LAM and 16 controls. FGF23 levels were higher in the LAM group than in the control group. In the LAM group, FGF23 levels above the optimal cutoff point distinguished 33% of the subjects who had nondiagnostic VEGF-D levels. Lower FGF23 levels were associated with impaired DLCO (p = 0.04), particularly for those with isolated diffusion impairment with no other spirometric abnormalities (p = 0.04). CONCLUSIONS: Our results suggest that FGF23 is associated with pulmonary diffusion abnormalities in LAM patients and elicit novel mechanisms of LAM pathogenesis. FGF23 alone or in combination with other molecules needs to be validated as a biomarker of LAM activity in future clinical research.

Lymphangioleiomyomatosis: circulating levels of FGF23 and pulmonary diffusion / Linfangioleiomiomatose: níveis circulantes de FGF23 e difusão pulmonar

ABSTRACT Objective: Lymphangioleiomyomatosis (LAM) is a rare, destructive disease of the lungs with a limited number of determinants of disease activity, which are a critical need for clinical trials. FGF23 has been implicated in several chronic pulmonary diseases. We aimed to determine the association between serum FGF23 levels and pulmonary function in a cohort of patients with LAM. Methods: This was a descriptive single-center study in which subjects with LAM and controls with unreported lung disease were recruited. Serum FGF23 levels were measured in all subjects. Clinical data, including pulmonary function testing, were retrospectively obtained from electronic medical records of LAM subjects. Associations between FGF23 levels and clinical features of LAM were explored via nonparametric hypothesis testing. Results: The sample comprised 37 subjects with LAM and 16 controls. FGF23 levels were higher in the LAM group than in the control group. In the LAM group, FGF23 levels above the optimal cutoff point distinguished 33% of the subjects who had nondiagnostic VEGF-D levels. Lower FGF23 levels were associated with impaired DLCO (p = 0.04), particularly for those with isolated diffusion impairment with no other spirometric abnormalities (p = 0.04). Conclusions: Our results suggest that FGF23 is associated with pulmonary diffusion abnormalities in LAM patients and elicit novel mechanisms of LAM pathogenesis. FGF23 alone or in combination with other molecules needs to be validated as a biomarker of LAM activity in future clinical research.

RESUMO Objetivo: A linfangioleiomiomatose (LAM) é uma doença rara e destrutiva dos pulmões com um número limitado de determinantes da atividade da doença, que são uma necessidade crítica para ensaios clínicos. O FGF23 já foi implicado em várias doenças pulmonares crônicas. O nosso objetivo foi determinar a associação entre os níveis séricos de FGF23 e a função pulmonar em uma coorte de pacientes com LAM. Métodos: Estudo descritivo unicêntrico no qual foram recrutados indivíduos com LAM e controles com doenças pulmonares não declaradas. Os níveis séricos de FGF23 foram medidos em todos os indivíduos. Os dados clínicos, incluindo testes de função pulmonar, foram obtidos retrospectivamente a partir dos prontuários eletrônicos dos indivíduos com LAM. As associações entre os níveis de FGF23 e as características clínicas da LAM foram exploradas por meio do teste de hipóteses não paramétrico. Resultados: A amostra incluiu 37 indivíduos com LAM e 16 controles. Os níveis de FGF23 foram mais altos no grupo LAM do que no grupo controle. No grupo LAM, níveis de FGF23 acima do ponto de corte ideal distinguiram 33% dos indivíduos com níveis não diagnósticos de VEGF-D. Níveis mais baixos de FGF23 estavam associados à DLCO comprometida (p = 0,04), particularmente naqueles com comprometimento isolado da difusão e sem outras alterações espirométricas (p = 0,04). Conclusões: Nossos resultados sugerem que o FGF23 está associado a alterações na difusão pulmonar em pacientes com LAM e potencialmente indicam novos mecanismos de patogênese da LAM. O FGF23 isoladamente ou em combinação com outras moléculas precisa ser validado como um biomarcador da atividade da LAM em futuras pesquisas clínicas.

Syndecan-2 regulates PAD2 to exert antifibrotic effects on RA-ILD fibroblasts.

Rheumatoid arthritis (RA)-associated interstitial lung disease (RA-ILD) is the most common pulmonary complication of RA, increasing morbidity and mortality. Anti-citrullinated protein antibodies have been associated with the development and progression of both RA and fibrotic lung disease; however, the role of protein citrullination in RA-ILD remains unclear. Here, we demonstrate that the expression of peptidylarginine deiminase 2 (PAD2), an enzyme that catalyzes protein citrullination, is increased in lung homogenates from subjects with RA-ILD and their lung fibroblasts. Chemical inhibition or genetic knockdown of PAD2 in RA-ILD fibroblasts attenuated their activation, marked by decreased myofibroblast differentiation, gel contraction, and extracellular matrix gene expression. Treatment of RA-ILD fibroblasts with the proteoglycan syndecan-2 (SDC2) yielded similar antifibrotic effects through regulation of PAD2 expression, phosphoinositide 3-kinase/Akt signaling, and Sp1 activation in a CD148-dependent manner. Furthermore, SDC2-transgenic mice exposed to bleomycin-induced lung injury in an inflammatory arthritis model expressed lower levels of PAD2 and were protected from the development of pulmonary fibrosis. Together, our results support a SDC2-sensitive profibrotic role for PAD2 in RA-ILD fibroblasts and identify PAD2 as a promising therapeutic target of RA-ILD.

Psychological impact of genetic and clinical screening for pulmonary fibrosis on asymptomatic first-degree relatives of affected individuals.

Screening for pulmonary fibrosis may help to identify early stages of the disease. We assessed the psychological impact of screening undiagnosed first-degree relatives of patients with pulmonary fibrosis by administering two validated measures after participants received their results: the Decisional Regret Scale and the Feelings About genomiC Testing Results Questionnaire. More than 90% of relatives reported either no or mild decisional regret. Increased measures of decisional regret and negative feelings were present in those found to have a low diffusion capacity of carbon monoxide or interstitial lung abnormalities. Results of telomere length and genetic testing did not significantly impact regret.

Quantitative computed tomography assessment of bronchiolitis obliterans syndrome after lung transplantation.

BACKGROUND: Bronchiolitis obliterans syndrome (BOS) is a clinical manifestation of chronic allograft rejection following lung transplantation. We examined the quantitative measurements of the proximal airway and vessels and pathologic correlations in subjects with BOS. METHODS: Patients who received a lung transplant at the Brigham and Women's Hospital between December 1, 2002 and December 31, 2010 were included in this study. We characterized the quantitative CT measures of proximal airways and vessels and pathological changes. RESULTS: Ninety-four (46.1%) of the 204 subjects were included in the study. There was a significant increase in the airway vessel ratio in subjects who developed progressive BOS compared to controls and non-progressors. There was a significant increase in airway lumen area and decrease in vessel cross-sectional area in patients with BOS compared to controls. Patients with BOS had a significant increase in proximal airway fibrosis compared to controls. CONCLUSIONS: BOS is characterized by central airway dilation and vascular remodeling, the degree of which is correlated to decrements in lung function. Our data suggest that progressive BOS is a pathologic process that affects both the central and distal airways.

Densitometric and local histogram based analysis of computed tomography images in patients with idiopathic pulmonary fibrosis.

BACKGROUND: Prior studies of clinical prognostication in idiopathic pulmonary fibrosis (IPF) using computed tomography (CT) have often used subjective analyses or have evaluated quantitative measures in isolation. This study examined associations between both densitometric and local histogram based quantitative CT measurements with pulmonary function test (PFT) parameters and mortality. In addition, this study sought to compare risk prediction scores that incorporate quantitative CT measures with previously described systems. METHODS: Forty six patients with biopsy proven IPF were identified from a registry of patients with interstitial lung disease at Brigham and Women's Hospital in Boston, MA. CT scans for each subject were visually scored using a previously published method. After a semi-automated method was used to segment the lungs from the surrounding tissue, densitometric measurements including the percent high attenuating area, mean lung density, skewness and kurtosis were made for the entirety of each patient's lungs. A separate, automated tool was used to detect and quantify the percent of lung occupied by interstitial lung features. These analyses were used to create clinical and quantitative CT based risk prediction scores, and the performance of these was compared to the performance of clinical and visual analysis based methods. RESULTS: All of the densitometric measures were correlated with forced vital capacity and diffusing capacity, as were the total amount of interstitial change and the percentage of interstitial change that was honeycombing measured using the local histogram method. Higher percent high attenuating area, higher mean lung density, lower skewness, lower kurtosis and a higher percentage of honeycombing were associated with worse transplant free survival. The quantitative CT based risk prediction scores performed similarly to the clinical and visual analysis based methods. CONCLUSIONS: Both densitometric and feature based quantitative CT measures correlate with pulmonary function test measures and are associated with transplant free survival. These objective measures may be useful for identifying high risk patients and monitoring disease progression. Further work will be needed to validate these measures and the quantitative imaging based risk prediction scores in other cohorts.

Pulmonary Vasculopathy Associated with FIGF Gene Mutation.

Vascular endothelial growth factor (VEGF)-D is capable of inducing angiogenesis and lymphangiogenesis through signaling via VEGF receptor (VEGFR)-2 and VEGFR-3, respectively. Mutations in the FIGF (c-fos-induced growth factor) gene encoding VEGF-D have not been reported previously. We describe a young male with a hemizygous mutation in the X-chromosome gene FIGF (c.352 G>A) associated with early childhood respiratory deficiency. Histologically, lungs showed ectatic pulmonary arteries and pulmonary veins. The mutation resulted in a substitution of valine to methionine at residue 118 of the VEGF-D protein. The resultant mutant protein had increased dimerization, induced elevated VEGFR-2 signaling, and caused aberrant angiogenesis in vivo. Our observations characterize a new subtype of congenital diffuse lung disease, provide a histological correlate, and support a critical role for VEGF-D in lung vascular development and homeostasis.

Detection of Rheumatoid Arthritis-Interstitial Lung Disease Is Enhanced by Serum Biomarkers.

RATIONALE: Interstitial lung disease (ILD), a leading cause of morbidity and mortality in rheumatoid arthritis (RA), is highly prevalent, yet RA-ILD is underrecognized. OBJECTIVES: To identify clinical risk factors, autoantibodies, and biomarkers associated with the presence of RA-ILD. METHODS: Subjects enrolled in Brigham and Women's Hospital Rheumatoid Arthritis Sequential Study (BRASS) and American College of Rheumatology (ACR) cohorts were evaluated for ILD. Regression models were used to assess the association between variables of interest and RA-ILD. Receiver operating characteristic curves were generated in BRASS to determine if a combination of clinical risk factors and autoantibodies can identify RA-ILD and if the addition of investigational biomarkers is informative. This combinatorial signature was subsequently tested in ACR. MEASUREMENTS AND MAIN RESULTS: A total of 113 BRASS subjects with clinically indicated chest computed tomography scans (41% with a spectrum of clinically evident and subclinical RA-ILD) and 76 ACR subjects with research or clinical scans (51% with a spectrum of RA-ILD) were selected. A combination of age, sex, smoking, rheumatoid factor, and anticyclic citrullinated peptide antibodies was strongly associated with RA-ILD (areas under the curve, 0.88 for BRASS and 0.89 for ACR). Importantly, a combinatorial signature including matrix metalloproteinase 7, pulmonary and activation-regulated chemokine, and surfactant protein D significantly increased the areas under the curve to 0.97 (P = 0.002, BRASS) and 1.00 (P = 0.016, ACR). Similar trends were seen for both clinically evident and subclinical RA-ILD. CONCLUSIONS: Clinical risk factors and autoantibodies are strongly associated with the presence of clinically evident and subclinical RA-ILD on computed tomography scan in two independent RA cohorts. A biomarker signature composed of matrix metalloproteinase 7, pulmonary and activation-regulated chemokine, and surfactant protein D significantly strengthens this association. These findings may facilitate identification of RA-ILD at an earlier stage, potentially leading to decreased morbidity and mortality.

Cesarean delivery among nulliparous women in Beirut: assessing predictors in nine hospitals.

BACKGROUND: Obstetric practice has witnessed a worldwide trend of increasing cesarean section rates in recent years. Similar trends have been observed in Lebanon, according to 2 studies conducted in 1996 and 1999. The objective of the present study was to assess the differences in predictors of cesarean delivery among nulliparous women in a "control hospital" with a low cesarean delivery rate (12.5%) and the rest of the National Collaborative Perinatal Neonatal Network (NCPNN) "study hospitals" with a higher cesarean delivery rate (31.4%). METHODS: Data were collected by the NCPNN database, which covers deliveries at 9 major hospitals located in the Greater Beirut area. Data analysis was performed on the 6,668 consecutive deliveries occurring between January 1, 2001, and December 31, 2002, at the NCPNN participating centers. The questionnaires included items that cover parental sociodemographic characteristics and maternal and newborn health characteristics. Sources of data included direct interviews with mothers after delivery and before hospital discharge and reviews of obstetric and nursery medical charts. Chi-square tests and t tests were performed for categorical and continuous clinical predictors of cesarean section. Logistic regression was performed to determine the odds of having a cesarean section for the study hospitals when compared with the control hospital. Odds ratios and 95% confidence intervals are reported. RESULTS: Variables in the study hospitals that correlated with a higher cesarean delivery rate were male obstetricians, day of the week, and mode of payment compared with the control hospital. CONCLUSIONS: In a country with a high cesarean section rate, 1 hospital met World Health Organization criteria for acceptable cesarean section rates, with no compromise in neonatal outcome. Further studies are needed to investigate potential policies to decrease the high cesarean section rate.