A Cluster-Randomized Trial of Blood-Pressure Reduction in Black Barbershops.

BACKGROUND: Uncontrolled hypertension is a major problem among non-Hispanic black men, who are underrepresented in pharmacist intervention trials in traditional health care settings. METHODS: We enrolled a cohort of 319 black male patrons with systolic blood pressure of 140 mm Hg or more from 52 black-owned barbershops (nontraditional health care setting) in a cluster-randomized trial in which barbershops were assigned to a pharmacist-led intervention (in which barbers encouraged meetings in barbershops with specialty-trained pharmacists who prescribed drug therapy under a collaborative practice agreement with the participants' doctors) or to an active control approach (in which barbers encouraged lifestyle modification and doctor appointments). The primary outcome was reduction in systolic blood pressure at 6 months. RESULTS: At baseline, the mean systolic blood pressure was 152.8 mm Hg in the intervention group and 154.6 mm Hg in the control group. At 6 months, the mean systolic blood pressure fell by 27.0 mm Hg (to 125.8 mm Hg) in the intervention group and by 9.3 mm Hg (to 145.4 mm Hg) in the control group; the mean reduction was 21.6 mm Hg greater with the intervention (95% confidence interval, 14.7 to 28.4; P<0.001). A blood-pressure level of less than 130/80 mm Hg was achieved among 63.6% of the participants in the intervention group versus 11.7% of the participants in the control group (P<0.001). In the intervention group, the rate of cohort retention was 95%, and there were few adverse events (three cases of acute kidney injury). CONCLUSIONS: Among black male barbershop patrons with uncontrolled hypertension, health promotion by barbers resulted in larger blood-pressure reduction when coupled with medication management in barbershops by specialty-trained pharmacists. (Funded by the National Heart, Lung, and Blood Institute and others; ClinicalTrials.gov number, NCT02321618 .).

A flexible joint model for multiple longitudinal biomarkers and a time-to-event outcome: With applications to dynamic prediction using highly correlated biomarkers.

In biomedical studies it is common to collect data on multiple biomarkers during study follow-up for dynamic prediction of a time-to-event clinical outcome. The biomarkers are typically intermittently measured, missing at some event times, and may be subject to high biological variations, which cannot be readily used as time-dependent covariates in a standard time-to-event model. Moreover, they can be highly correlated if they are from in the same biological pathway. To address these issues, we propose a flexible joint model framework that models the multiple biomarkers with a shared latent reduced rank longitudinal principal component model and correlates the latent process to the event time by the Cox model for dynamic prediction of the event time. The proposed joint model for highly correlated biomarkers is more flexible than some existing methods since the latent trajectory shared by the multiple biomarkers does not require specification of a priori parametric time trend and is determined by data. We derive an expectation-maximization (EM) algorithm for parameter estimation, study large sample properties of the estimators, and adapt the developed method to make dynamic prediction of the time-to-event outcome. Bootstrap is used for standard error estimation and inference. The proposed method is evaluated using simulations and illustrated on a lung transplant data to predict chronic lung allograft dysfunction (CLAD) using chemokines measured in bronchoalveolar lavage fluid of the patients.

Sustainability of Blood Pressure Reduction in Black Barbershops.

BACKGROUND: We developed a new model of hypertension care for non-Hispanic black men that links health promotion by barbers to medication management by American Society of Hypertension-certified pharmacists and demonstrated efficacy in a 6-month cluster-randomized trial. The marked reduction in systolic blood pressure (BP) seen at 6 months warranted continuing the trial through 12 months to test sustainability, a necessary precondition for implementation research. METHODS: We enrolled a cohort of 319 black male patrons with systolic BP ≥140 mm Hg at baseline. Fifty-two Los Angeles County barbershops were assigned to either a pharmacist-led intervention or an active control group. In the intervention group, barbers promoted follow-up with pharmacists who prescribed BP medication under a collaborative practice agreement with patrons' primary care providers. In the control group, barbers promoted follow-up with primary care providers and lifestyle modification. After BP assessment at 6 months, the intervention continued with fewer in-person pharmacist visits to test whether the intervention effect could be sustained safely for 1 year while reducing pharmacist travel time. Final BP and safety outcomes were assessed in both groups at 12 months. RESULTS: At baseline, mean systolic BP was 152.4 mm Hg in the intervention group and 154.6 mm Hg in the control group. At 12 months, mean systolic BP fell by 28.6 mm Hg (to 123.8 mm Hg) in the intervention group and by 7.2 mm Hg (to 147.4 mm Hg) in the control group. The mean reduction was 20.8 mm Hg greater in the intervention (95% CI, 13.9-27.7; P<0.0001). A BP <130/80 mm Hg was achieved by 68.0% of the intervention group versus 11.0% of the control group ( P<0.02). These new 12-month efficacy data are statistically indistinguishable from our previously reported 6-month data. No treatment-related serious adverse events occurred in either group over 12 months. Cohort retention at 12 months was 90% in both groups. CONCLUSIONS: Among black male barbershop patrons with uncontrolled hypertension, health promotion by barbers resulted in large and sustained BP reduction over 12 months when coupled with medication management by American Society of Hypertension-certified pharmacists. Broad-scale implementation research is both justified and warranted. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov . Unique identifier: NCT 02321618.

High Carbon Monoxide Levels from Charcoal Combustion Mask Acute Endothelial Dysfunction Induced by Hookah (Waterpipe) Smoking in Young Adults.

BACKGROUND: Hookah smoking is marketed to youth as a harmless alternative to cigarettes. Although cigarette smoking acutely impairs endothelial function, the effect of smoking fruit-flavored hookah tobacco is unknown. Because charcoal traditionally is used to heat the hookah tobacco in the waterpipe, hookah smoke delivers tobacco toxicants and nicotine plus charcoal combustion products: not only carbon-rich nanoparticles, oxidants that may destroy nitric oxide and impair endothelial function, but also large amounts of carbon monoxide (CO), a putative vasodilator molecule. METHODS: To test the acute effect of hookah smoking on endothelial function, in young adult hookah smokers (n=30, age 26±1 years, mean±SE), we measured plasma nicotine, exhaled CO, and brachial artery flow-mediated dilation (FMD) before and after charcoal-heated hookah smoking. To remove the effect of charcoal combustion, the same measurements were performed when the same flavored hookah tobacco product was heated electrically (n=20). As a positive internal control, we studied age-matched cigarette smokers (n=15) who smoked 1 cigarette. To isolate the effect of the CO boost on FMD, hookah smokers (n=8) inhaled a 0.1% CO gas mixture to approximate their CO boost achieved with charcoal-heated hookah smoking. RESULTS: Nicotine levels increased similarly with all types of smoking, whereas exhaled CO increased 9- to 10-fold more after charcoal-heated hookah than after either electrically heated hookah or cigarette smoking. FMD did not decrease after smoking charcoal-heated hookah but instead increased by +43±7% ( P<0.001). In contrast, FMD decreased by -27±4% ( P<0.001) after smoking electrically heated hookah, comparable to the decrease after cigarette smoking. FMD increased markedly by 138±71% ( P<0.001) after breathing CO gas, 2.8 times more than the increase induced in the same subjects after smoking charcoal-heated hookah ( P<0.001), despite comparable increases in exhaled CO (24±1 versus 28±3 ppm, hookah versus CO). CONCLUSIONS: Smoking hookah tobacco, similar to cigarette tobacco, acutely impairs endothelial function. With traditional charcoal-heated hookah smoking, the acute endothelial dysfunction is masked by high levels of carbon monoxide, a potent vasodilator molecule generated by charcoal combustion. With respect to large-artery endothelial function, smoking hookah is not harmless. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov . Unique identifiers: NCT03616002 and NCT03067701.

Regional Node Basin Recurrence in Melanoma Patients: More Common After Node Dissection for Macroscopic Rather than Clinically Occult Nodal Disease.

BACKGROUND: Recommended treatment for patients with sentinel lymph node (SLN)-positive melanoma has recently changed. Randomized trials demonstrated equivalent survival with close observation versus completion lymph node dissection (CLND), but increased regional node recurrence. We evaluated factors related to in-basin nodal recurrence after lymphadenectomy (LND) for SLN-positive or macroscopic nodal metastases. METHODS: An institutional database and the first Multicenter Selective Lymphadenectomy Trial (MSLT-I) were analyzed independently. Exclusions were multiple primaries, multi-basin involvement, or in-transit metastases. Patient demographics, primary tumor thickness and ulceration, lymph nodes retrieved, and use of adjuvant radiotherapy were analyzed. Multivariate analyses were performed to determine factors predicting in-basin nodal recurrence (significance p ≤ 0.05). RESULTS: The retrospective cohort (577 patients) showed an in-basin failure rate of 6.6% after CLND for a positive SLN and 13.1% after LND for palpable disease (p = 0.001). This recurrence risk persisted after adjustment for patient, tumor, and LND factors [hazard ratio (HR) 2.32; p = 0.004]. In the MSLT-I cohort (326 patients), the failure rate after CLND following SLNB was 6.2%, but 10.1% after LND for palpable recurrence in observation patients. After adjustment for other factors, macroscopic disease was associated with an increased risk of recurrence after LND (HR 2.24; p = 0.05). CONCLUSION: After LND for melanoma, in-basin recurrence is infrequent, but a clinically significant fraction will fail. Failure is less likely if dissection is performed for clinically occult disease. Further research is warranted to evaluate the long-term regional control and quality of life associated with nodal basin observation, which has now become standard practice.

Short-term progression of interstitial lung disease in systemic sclerosis predicts long-term survival in two independent clinical trial cohorts.

OBJECTIVE: To assess survival and identify predictors of survival in patients with systemic sclerosis-interstitial lung disease (SSc-ILD) who participated in the Scleroderma Lung Studies (SLS) I and II. METHODS: SLS I randomised 158 patients with SSc-ILD to 1 year of oral cyclophosphamide (CYC) vs placebo. SLS II randomised 142 patients to 1 year of oral CYC followed by 1 year of placebo vs 2 years of mycophenolate mofetil. Counting process Cox proportional hazard modelling identified variables associated with long-term mortality in SLS I and II. Internal validation was performed using joint modelling. RESULTS: After a median follow-up of 8 years, 42% of SLS I patients died, and when known the cause of death was most often attributable to SSc. There was no significant difference in the time to death between treatment arms in SLS I or II. Higher baseline skin score, older age, and a decline in the forced vital capacity (FVC) and the diffusing capacity for carbon monoxide (DLCO) over 2 years were independently associated with an increased risk of mortality in SLS I. The Cox model identified the same mortality predictor variables using the SLS II data. CONCLUSION: In addition to identifying traditional mortality risk factors in SSc (skin score, age), this study demonstrated that a decline in FVC and DLCO over 2 years was a better predictor of mortality than baseline FVC and DLCO. These findings suggest that short-term changes in surrogate measures of SSc-ILD progression may have important effects on long-term outcomes.

Randomized phase 2 trial of erlotinib in combination with high-dose celecoxib or placebo in patients with advanced non-small cell lung cancer.

BACKGROUND: Cyclooxygenase 2 (COX-2)-dependent signaling represents a potential mechanism of resistance to therapy with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors. This is mediated in part through an EGFR-independent activation of mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (Erk) by prostaglandin E2 (PGE2). PGE2 promotes downregulation of E cadherin and epithelial to mesenchymal transition. The current study investigated EGFR and COX-2 inhibition in patients with non-small cell lung cancer (NSCLC) and elevated baseline urinary metabolite of PGE2 (PGEM). METHODS: Patients with stage IIIB/IV (AJCC 6th edition) NSCLC who progressed after at least 1 line of therapy or refused standard chemotherapy were randomized to receive erlotinib and celecoxib versus erlotinib and placebo. The primary endpoint was progression-free survival (PFS) with 80% power to detect a 50% improvement with a 1-sided significance level of .2 in the intent-to-treat and elevated baseline PGEM populations. Secondary endpoints included response rate, overall survival, and evaluation of molecular markers to assess targeting COX-2-related pathways and evaluate EGFR tyrosine kinase inhibitor resistance. RESULTS: A total of 107 patients were enrolled with comparable baseline characteristics. Among the patients treated with celecoxib, those with wild-type EGFR were found to have an increased PFS (3.2 months vs 1.8 months; P = .03). PFS was numerically improved among patients in the intent-to-treat group who received erlotinib and celecoxib compared with those treated with erlotinib and placebo (5.4 months vs 3.5 months; P = .33) and was increased in patients in the erlotinib and celecoxib arm with elevated baseline PGEM (5.4 months vs 2.2 months; P = .15). Adverse events were similar in both treatment arms. CONCLUSIONS: The combination of erlotinib and celecoxib did not appear to improve outcomes in an unselected population, but selection by elevated baseline PGEM led to an increase in PFS with this combination. Patients with EGFR wild-type status may benefit from the combination of erlotinib and celecoxib.

Cocaine-induced vasoconstriction in the human coronary microcirculation: new evidence from myocardial contrast echocardiography.

BACKGROUND: Cocaine is a major cause of acute coronary syndrome, especially in young adults; however, the mechanistic underpinning of cocaine-induced acute coronary syndrome remains limited. Previous studies in animals and in patients undergoing cardiac catheterization suggest that cocaine constricts coronary microvessels, yet direct evidence is lacking. METHODS AND RESULTS: We used myocardial contrast echocardiography to test the hypothesis that cocaine causes vasoconstriction in the human coronary microcirculation. Measurements were performed at baseline and after a low, nonintoxicating dose of intranasal cocaine (2 mg/kg) in 10 healthy cocaine-naïve young men (median age, 32 years). Postdestruction time-intensity myocardial contrast echocardiography kinetic data were fit to the equation y=A(1-e(-ßt)) to quantify functional capillary blood volume (A), microvascular flow velocity (ß), and myocardial perfusion (A×ß). Heart rate, mean arterial pressure, and left ventricular work (2-dimensional echocardiography) were measured before and 45 minutes after cocaine. Cocaine increased mean arterial pressure (by 14±2 mm Hg [mean±SE]), heart rate (by 8±3 bpm), and left ventricular work (by 50±18 mm Hg·mL(-1)·bpm(-1)). Despite the increases in these determinants of myocardial oxygen demand, myocardial perfusion decreased by 30% (103.7±9.8 to 75.9±10.8 arbitrary units [AU]/s; P<0.01) mainly as a result of decreased capillary blood volume (133.9±5.1 to 111.7±7.7 AU; P<0.05) with no significant change in microvascular flow velocity (0.8±0.1 to 0.7±0.1 AU). CONCLUSIONS: In healthy cocaine-naïve young adults, a low-dose cocaine challenge evokes a sizeable decrease in myocardial perfusion. Moreover, the predominant effect is to decrease myocardial capillary blood volume rather than microvascular flow velocity, suggesting a specific action of cocaine to constrict terminal feed arteries.

CXCR3 ligands are associated with the continuum of diffuse alveolar damage to chronic lung allograft dysfunction.

RATIONALE: After lung transplantation, insults to the allograft generally result in one of four histopathologic patterns of injury: (1) acute rejection, (2) lymphocytic bronchiolitis, (3) organizing pneumonia, and (4) diffuse alveolar damage (DAD). We hypothesized that DAD, the most severe form of acute lung injury, would lead to the highest risk of chronic lung allograft dysfunction (CLAD) and that a type I immune response would mediate this process. OBJECTIVES: Determine whether DAD is associated with CLAD and explore the potential role of CXCR3/ligand biology. METHODS: Transbronchial biopsies from all lung transplant recipients were reviewed. The association between the four injury patterns and subsequent outcomes were evaluated using proportional hazards models with time-dependent covariates. Bronchoalveolar lavage (BAL) concentrations of the CXCR3 ligands (CXCL9/MIG, CXCL10/IP10, and CXCL11/ITAC) were compared between allograft injury patterns and "healthy" biopsies using linear mixed-effects models. The effect of these chemokine alterations on CLAD risk was assessed using Cox models with serial BAL measurements as time-dependent covariates. MEASUREMENTS AND MAIN RESULTS: There were 1,585 biopsies from 441 recipients with 62 episodes of DAD. An episode of DAD was associated with increased risk of CLAD (hazard ratio, 3.0; 95% confidence interval, 1.9-4.7) and death (hazard ratio, 2.3; 95% confidence interval, 1.7-3.0). There were marked elevations in BAL CXCR3 ligand concentrations during DAD. Furthermore, prolonged elevation of these chemokines in serial BAL fluid measurements predicted the development of CLAD. CONCLUSIONS: DAD is associated with marked increases in the risk of CLAD and death after lung transplantation. This association may be mediated in part by an aberrant type I immune response involving CXCR3/ligands.

An exploration of fixed and random effects selection for longitudinal binary outcomes in the presence of nonignorable dropout.

We explore a Bayesian approach to selection of variables that represent fixed and random effects in modeling of longitudinal binary outcomes with missing data caused by dropouts. We show via analytic results for a simple example that nonignorable missing data lead to biased parameter estimates. This bias results in selection of wrong effects asymptotically, which we can confirm via simulations for more complex settings. By jointly modeling the longitudinal binary data with the dropout process that possibly leads to nonignorable missing data, we are able to correct the bias in estimation and selection. Mixture priors with a point mass at zero are used to facilitate variable selection. We illustrate the proposed approach using a clinical trial for acute ischemic stroke.

Joint analysis of bivariate longitudinal ordinal outcomes and competing risks survival times with nonparametric distributions for random effects.

We propose a semiparametric joint model for bivariate longitudinal ordinal outcomes and competing risks failure time data. The association between the longitudinal and survival endpoints is captured by latent random effects. This approach generalizes previous joint analysis that considers only one response variable at the longitudinal endpoint. One unique feature of the proposed model is that we relax the commonly used normality assumption for random effects and leave the distribution completely unspecified. We use a modified version of the vertex exchange method in conjunction with an expectation-maximization algorithm to estimate the random effects distribution and model parameters. We show via simulations that robust parameter estimates are obtained from the proposed method under various scenarios. We illustrate the approach using cough severity and frequency data from a scleroderma lung study.

Predicting treatment outcomes and responder subsets in scleroderma-related interstitial lung disease.

OBJECTIVE: To identify baseline characteristics of patients with scleroderma-related interstitial lung disease (SSc-ILD) that could serve as predictors of the most favorable response to 12-month treatment with oral cyclophosphamide (CYC). METHODS: Regression analyses were retrospectively applied to the Scleroderma Lung Study data in order to identify baseline characteristics that correlated with the absolute change in forced vital capacity (FVC) (% predicted values) and the placebo-adjusted change in % predicted FVC over time (the CYC treatment effect). RESULTS: Completion of the CYC arm of the Scleroderma Lung Study was associated with a placebo-adjusted improvement in the % predicted FVC of 2.11% at 12 months, which increased to 4.16% when patients were followed up for another 6 months (P=0.014). Multivariate regression analyses identified the maximal severity of reticular infiltrates (assessed as maximum fibrosis scores) on high-resolution computed tomography (HRCT) at baseline, the modified Rodnan skin thickness score (MRSS) at baseline, and the Mahler baseline dyspnea index as independent correlates of treatment response. When patients were stratified on the basis of whether 50% or more of any lung zone was involved by reticular infiltrates on HRCT and/or whether patients exhibited an MRSS of at least 23, a subgroup of patients emerged in whom there was an average CYC treatment effect of 9.81% at 18 months (P<0.001). Conversely, there was no treatment effect (a -0.58% difference) in patients with less severe HRCT findings and a lower MRSS at baseline. CONCLUSION: A retrospective analysis of the Scleroderma Lung Study data identified the severity of reticular infiltrates on baseline HRCT and the baseline MRSS as patient features that might be predictive of responsiveness to CYC therapy.

A method to estimate treatment efficacy among latent subgroups of a randomized clinical trial.

Subgroup analysis arises in clinical trials research when we wish to estimate a treatment effect on a specific subgroup of the population distinguished by baseline characteristics. Many trial designs induce latent subgroups such that subgroup membership is observable in one arm of the trial and unidentified in the other. This occurs, for example, in oncology trials when a biopsy or dissection is performed only on subjects randomized to active treatment. We discuss a general framework to estimate a biological treatment effect on the latent subgroup of interest when the survival outcome is right-censored and can be appropriately modelled as a parametric function of covariate effects. Our framework builds on the application of instrumental variables methods to all-or-none treatment noncompliance. We derive a computational method to estimate model parameters via the EM algorithm and provide guidance on its implementation in standard software packages. The research is illustrated through an analysis of a seminal melanoma trial that proposed a new standard of care for the disease and involved a biopsy that is available only on patients in the treatment arm.

Patient education integrated with acupuncture for relief of cancer-related fatigue randomized controlled feasibility study.

BACKGROUND: Cancer-related fatigue (CRF) is a prominent clinical problem. There are calls for multi-modal interventions. METHODS: We assessed the feasibility of delivering patient education integrated with acupuncture for relief of CRF in a pilot randomized controlled trial (RCT) with breast cancer survivors using usual care as control. Social cognitive and integrative medicine theories guided integration of patient education with acupuncture into a coherent treatment protocol. The intervention consisted of two parts. First, patients were taught to improve self-care by optimizing exercise routines, improving nutrition, implementing some additional evidence-based cognitive behavioral techniques such as stress management in four weekly 50-minute sessions. Second, patients received eight weekly 50-minute acupuncture sessions. The pre-specified primary outcome, CRF, was assessed with the Brief Fatigue Inventory (BFI). Secondary outcomes included three dimensions of cognitive impairment assessed with the FACT-COGv2. RESULTS: Due to difficulties in recruitment, we tried several methods that led to the development of a tailored recruitment strategy: we enlisted oncologists into the core research team and recruited patients completing treatment from oncology waiting rooms. Compared to usual care control, the intervention was associated with a 2.38-point decline in fatigue as measured by the BFI (90% Confidence Interval from 0.586 to 5.014; p <0.10). Outcomes associated with cognitive dysfunction were not statistically significant. CONCLUSIONS: Patient education integrated with acupuncture had a very promising effect that warrants conducting a larger RCT to confirm findings. An effective recruitment strategy will be essential for the successful execution of a larger-scale trial. TRIAL REGISTRATION: NCT00646633.

A general joint model for longitudinal measurements and competing risks survival data with heterogeneous random effects.

This article studies a general joint model for longitudinal measurements and competing risks survival data. The model consists of a linear mixed effects sub-model for the longitudinal outcome, a proportional cause-specific hazards frailty sub-model for the competing risks survival data, and a regression sub-model for the variance-covariance matrix of the multivariate latent random effects based on a modified Cholesky decomposition. The model provides a useful approach to adjust for non-ignorable missing data due to dropout for the longitudinal outcome, enables analysis of the survival outcome with informative censoring and intermittently measured time-dependent covariates, as well as joint analysis of the longitudinal and survival outcomes. Unlike previously studied joint models, our model allows for heterogeneous random covariance matrices. It also offers a framework to assess the homogeneous covariance assumption of existing joint models. A Bayesian MCMC procedure is developed for parameter estimation and inference. Its performances and frequentist properties are investigated using simulations. A real data example is used to illustrate the usefulness of the approach.

Racial Disparities in Systemic Sclerosis: Short- and Long-Term Outcomes Among African American Participants of SLS I and II.

OBJECTIVE: To evaluate short- and long-term outcomes of African American (AA) participants of Scleroderma Lung Studies (SLS) I and II. METHODS: SLS I randomized 158 participants with systemic sclerosis-interstitial lung disease (SSc-ILD) to 1 year of oral cyclophosphamide (CYC) versus placebo. SLS II randomized 142 participants with SSc-ILD to 1 year of oral CYC followed by 1 year of placebo versus 2 years of mycophenolate (MMF). Joint models compared the course of forced vital capacity (FVC) and diffusing capacity for carbon monoxide (DLCO) between AA and non-AA, and Cox proportional hazard models assessed long-term morbidity and mortality outcomes. RESULTS: In SLS I, there was no difference in the course of the FVC or DLCO between AA and non-AA in either treatment arm. In SLS II, AA had an improved course of the FVC compared with non-AA in the CYC arm; in the MMF arm, there was no difference in FVC course. There was no difference in DLCO course in either arm. Time to death and respiratory failure were similar for AA and non-AA in SLS I. There was a trend for improved survival and time to respiratory failure in AA compared with non-AA in SLS II. AA race was not independently associated with mortality in the SLS I or II in the Cox models. CONCLUSION: Data from two randomized controlled trials demonstrated that AA patients with SSc-ILD have similar morbidity and mortality outcomes compared with non-AA patients. These findings contrast with the racial disparities described in prior observational studies and warrant further investigation.

Predictive Significance of Serum Interferon-Inducible Protein Score for Response to Treatment in Systemic Sclerosis-Related Interstitial Lung Disease.

OBJECTIVE: Response to immunosuppression is highly variable in systemic sclerosis (SSc)-related interstitial lung disease (ILD). This study was undertaken to determine whether a composite serum interferon (IFN)-inducible protein score exhibits predictive significance for the response to immunosuppression in SSc-ILD. METHODS: Serum samples collected in the Scleroderma Lung Study II, a randomized controlled trial of mycophenolate mofetil (MMF) versus cyclophosphamide (CYC), were examined. Results were validated in an independent observational cohort receiving active treatment. A composite score of 6 IFN-inducible proteins IFNγ-inducible 10-kd protein, monokine induced by IFNγ, monocyte chemotactic protein 2, ß2 -microglobulin, tumor necrosis factor receptor type II, and macrophage inflammatory protein 3ß) was calculated, and its predictive significance for longitudinal forced vital capacity percent predicted measurements was evaluated. RESULTS: Higher baseline IFN-inducible protein score predicted better response over 3 to 12 months in the MMF arm (point estimate = 0.41, P = 0.001) and CYC arm (point estimate = 0.91, P = 0.009). In contrast, higher baseline C-reactive protein (CRP) levels were predictive of a worse ILD course in both treatment arms. The predictive significance of the IFN-inducible protein score and CRP levels remained after adjustment for baseline demographic and clinical predictors. During the second year of treatment, in which patients in the CYC arm were switched to placebo, a higher IFN-inducible protein score at 12 months showed a trend toward predicting a worse ILD course (point estimate = -0.61, P = 0.068), while it remained predictive of better response to active immunosuppression in the MMF arm (point estimate = 0.28, P = 0.029). The predictive significance of baseline IFN-inducible protein score was replicated in the independent cohort (rs = 0.43, P = 0.028). CONCLUSION: A higher IFN-inducible protein score in SSc-ILD is predictive of better response to immunosuppression and could potentially be used to identify patients who may derive the most benefit from MMF or CYC.

Joint modeling of longitudinal ordinal data and competing risks survival times and analysis of the NINDS rt-PA stroke trial.

Existing joint models for longitudinal and survival data are not applicable for longitudinal ordinal outcomes with possible non-ignorable missing values caused by multiple reasons. We propose a joint model for longitudinal ordinal measurements and competing risks failure time data, in which a partial proportional odds model for the longitudinal ordinal outcome is linked to the event times by latent random variables. At the survival endpoint, our model adopts the competing risks framework to model multiple failure types at the same time. The partial proportional odds model, as an extension of the popular proportional odds model for ordinal outcomes, is more flexible and at the same time provides a tool to test the proportional odds assumption. We use a likelihood approach and derive an EM algorithm to obtain the maximum likelihood estimates of the parameters. We further show that all the parameters at the survival endpoint are identifiable from the data. Our joint model enables one to make inference for both the longitudinal ordinal outcome and the failure times simultaneously. In addition, the inference at the longitudinal endpoint is adjusted for possible non-ignorable missing data caused by the failure times. We apply the method to the NINDS rt-PA stroke trial. Our study considers the modified Rankin Scale only. Other ordinal outcomes in the trial, such as the Barthel and Glasgow scales, can be treated in the same way.

Peripheral Blood Flow Changes to Cutaneous and Muscular Beds in Response to Acute Hookah Smoking.

Hookah (waterpipe) smoking is a growing tobacco epidemic. Though perceived as a safer tobacco alternative, hookah smoke contains, in addition to tobacco combustion products, large amounts of charcoal combustion products-implicated in cardiovascular disease-from the burning charcoal used to heat the flavored tobacco. To date, little is known on the vascular effects of hookah smoking. The aim of this study was to characterize the peripheral circulatory response to acute hookah smoking in cutaneous and muscular beds. In 21 healthy young adult habitual hookah smokers who did not smoke cigarettes (age 24 ± 1 years, mean ± SE), we measured plasma nicotine, exhaled carbon monoxide, skin blood flow (laser Doppler velocimetry) and calf muscle blood flow (strain-gauge plethysmography) before and for up to 60 minutes after ad lib hookah smoking. In nine subjects, nonsmoking time-control studies were performed. Hookah smoking, which increased plasma nicotine by 5.8 ng/ml (from 0.6 ± 0.1 to 6.4 ± 1.3, p <0.001) and exhaled carbon monoxide by 27 ppm (from 2.7 ± 0.2 to 29.5 ± 2.2, p <0.001), decreased skin blood flow by 23% (20.1 ± 2.8 to 14.8 ± 1.9 units, p <0.001) and increased skeletal muscle blood flow by 34% (2.3 ± 0.1 to 2.9 ± 0.2 units, p = 0.010). These responses required more than one hour to recover after smoking cessation. All cardiovascular parameters were unchanged in the nonsmoking time-control studies. Although perceived to be innocuous, hookah smoking produces acute cutaneous vasoconstriction with skeletal muscle vasodilation, a dissociated pattern of peripheral blood flow responses that is characteristic of nicotine and carbon monoxide. In conclusion, these findings provide objective evidence to challenge the perception that hookah smoking is a safer tobacco alternative.