Polysomnographic Assessment of Sleep Disturbances in Cancer Development: A Historical Multicenter Clinical Cohort Study.

BACKGROUND: Many cellular processes are controlled by sleep. Therefore, alterations in sleep might be expected to stress biological systems that could influence malignancy risk. RESEARCH QUESTION: What is the association between polysomnographic measures of sleep disturbances and incident cancer, and what is the validity of cluster analysis in identifying polysomnography phenotypes? STUDY DESIGN AND METHODS: We conducted a retrospective multicenter cohort study using linked clinical and provincial health administrative data on consecutive adults free of cancer at baseline with polysomnography data collected between 1994 and 2017 in four academic hospitals in Ontario, Canada. Cancer status was derived from registry records. Polysomnography phenotypes were identified by k-means cluster analysis. A combination of validation statistics and distinguishing polysomnographic features was used to select clusters. Cox cause-specific regressions were used to assess the relationship between identified clusters and incident cancer. RESULTS: Among 29,907 individuals, 2,514 (8.4%) received a diagnosis of cancer over a median of 8.0 years (interquartile range, 4.2-13.5 years). Five clusters were identified: mild (mildly abnormal polysomnography findings), poor sleep, severe OSA or sleep fragmentation, severe desaturations, and periodic limb movements of sleep (PLMS). The associations between cancer and all clusters compared with the mild cluster were significant while controlling for clinic and year of polysomnography. When additionally controlling for age and sex, the effect remained significant only for PLMS (adjusted hazard ratio [aHR], 1.26; 95% CI, 1.06-1.50) and severe desaturations (aHR, 1.32; 95% CI, 1.04-1.66). Further controlling for confounders, the effect remained significant for PLMS, but was attenuated for severe desaturations. INTERPRETATION: In a large cohort, we confirmed the importance of polysomnographic phenotypes and highlighted the role that PLMS and oxygenation desaturation may play in cancer. Using this study's findings, we also developed an Excel (Microsoft) spreadsheet (polysomnography cluster classifier) that can be used to validate the identified clusters on new data or to identify which cluster a patient belongs to. TRIAL REGISTRY: ClinicalTrials.gov; Nos.: NCT03383354 and NCT03834792; URL: www. CLINICALTRIALS: gov.

A systematic scoping review of primary health care service outreach for homeless populations.

BACKGROUND: Homeless populations (HPs) have difficulties obtaining necessary medical care, and primary health care service outreach (PHSO) might be useful to bridge this gap. OBJECTIVE: Using the Centre for Evidence-Based Management Critically Appraised Topics framework, to provide systematic evidence of the usefulness of PHSO interventions for HPs. METHODS: A systematic search was conducted in 4 electronic databases: PubMed, Web of Science, CINAHL, and Cochrane (publication dates between January 1980 and November 2020). In total, 2,872 articles were identified. Primary research about PHSO for HPs in high-income countries were included. Data were extracted from eligible studies, summarized, and collated into a narrative account. RESULTS: Twenty-four studies that described and evaluated PHSO interventions for adults experiencing homelessness were selected in the final synthesis. Most studies had a nonrandomized design. PHSO was found to successfully address some barriers to health care access for HPs through flexible appointments in convenient locations, fostering an understanding relationship between doctor and patients, and provision of additional basic necessities and referrals. Outreach was provided for a range of health care concerns, and several solutions to engage more HPs in primary care, improve continuity of care and to decrease the running costs were identified. Outreach also helped to implement preventative measures and reduced emergency service admissions. CONCLUSION: Our review adds to the evidence that PHSO likely improves health care access for HPs. Further studies over longer time periods, involving collaborations with experts with lived experience of homelessness, and utilizing randomized study designs are needed to test outreach efficacy.

The contribution of respiratory and hearing protection use to psychological distress in the workplace: a scoping review.

OBJECTIVE: Workers from various industries use personal protective equipment (PPE) including masks, respirators, and hearing protection to reduce their exposures to workplace hazards. Many studies have evaluated the physiological impacts of PPE use, but few have assessed the psychological impacts. The aim of the present study was to carry out a scoping review to compile existing evidence and determine the extent of knowledge on workplace mask, respirator or hearing protection use as a psychosocial hazard (stressor) that could result in a stress response and potentially lead to psychological injury. METHODS: The scoping review followed recognized methods and was conducted using Ovid Emcare, PubMed, Sage Journals, ScienceDirect, Scopus, SpringerLink, Google Scholar and preprint databases (OSF Preprints and medRxiv). Articles on the stressors associated with the use of masks, respirators, and hearing protection were included. The extracted data included author(s) name, year of publication, title of article, study design, population data, stressors assessed, and key findings. RESULTS: We retrieved 650 articles after removal of duplicates, of which 26 were deemed eligible for inclusion for review. Identified factors associated with PPE use that could potentially create a stress response were identified: communication impacts, physical impacts, psychological illness symptoms, cognitive impacts, and perceived PPE-related impacts. Evidence for respirators suggest that there may be psychological injury associated with their use. However, hearing protection appears to have a protective effect in reducing psychological symptoms such as anxiety, depression, and aggression. CONCLUSIONS: Mask or respirator use may lead to an increase in work-related stress. Whereas hearing protection may have protective effects against psychological symptoms and improves speech intelligibility. More research is needed to better understand potential psychosocial impacts of mask, respirator and/or hearing protection use.

Polysomnographic Markers of Obstructive Sleep Apnea Severity and Cancer-related Mortality: A Large Retrospective Multicenter Clinical Cohort Study.

Rationale: The evidence for an association between cancer survival and obstructive sleep apnea (OSA) remains underexplored. Objectives: To evaluate an association between markers of OSA severity (respiratory disturbances, hypoxemia, and sleep fragmentation) and cancer-related mortality in individuals with previously diagnosed cancer. Methods: We conducted a multicenter retrospective cohort study using linked clinical and provincial health administrative data on consecutive adults who underwent a diagnostic sleep study between 1994 and 2017 in four Canadian academic hospitals and were previously diagnosed with cancer through the Ontario Cancer Registry. Multivariable cause-specific Cox regressions were used to address the research objective. Results: We included 2,222 subjects. Over a median follow-up time of 5.6 years (interquartile range [IQR], 2.7-9.1 years), 261/2,222 (11.7%) individuals with prevalent cancer died from cancer-related causes, which accounted for 44.2% (261/590) of all-cause death. Controlling for age, sex, alcohol use disorder, prior heart failure, chronic obstructive pulmonary disease, hypertension, diabetes, treatment for OSA, clinic site, year of the sleep study, and time since the cancer diagnosis, measures of hypoxemia and sleep fragmentation, but not apnea-hypopnea index, were significantly associated with the cancer-specific mortality: percentage of time spent with arterial oxygen saturation (SaO2) < 90% (hazard ratio [HR] per 5% increase, 1.05; 95% confidence interval, 1.01-1.09); mean SaO2 (HR per 3% increase, 0.79; 0.68-0.92); and percentage of stage 1 sleep (HR per 16% increase, 1.27; 1.07-1.51). Conclusions: In a large clinical cohort of adults with suspected OSA and previously diagnosed cancer, measures of nocturnal hypoxemia and sleep fragmentation as markers of OSA severity were significantly associated with cancer-related mortality, suggesting the need for more targeted risk awareness.

The relationship between opioid use and obstructive sleep apnea: A systematic review and meta-analysis.

We conducted a systematic review to address limited evidence suggesting that opioids may induce or aggravate obstructive sleep apnea (OSA). All clinical trials or observational studies on adults from 1946 to 2018 found through MEDLINE, EMBASE, CINAHL, PsycINFO, Cochrane Databases were eligible. We assessed the quality of the studies using published guidelines. Fifteen studies (six clinical trials and nine observational) with only two of good quality were included. Fourteen studies investigated the impact of opioids on the presence or severity of OSA, four addressed the effects of treatment for OSA  in opioid users, and none explored the consequences of opioid use in individuals with OSA. Eight of 14 studies found no significant relationship between opioid use or dose and apnea-hypopnea index (AHI) or degree of nocturnal desaturation. A random-effects meta-analysis (n = 10) determined the pooled mean change in AHI associated with opioid use of 1.47/h (-2.63-5.57; I2 = 65%). Three of the four studies found that continuous positive airway pressure (CPAP) therapy reduced AHI by 17-30/h in opioid users with OSA. Bilevel therapy with a back-up rate and adaptive servo-ventilation (ASV) without mandatory pressure support successfully normalized AHI (≤5) in opioid users. Limited by a paucity of good-quality studies, our review did not show a significant relationship between opioid use and the severity of OSA. There was some evidence that CPAP, Bilevel therapy, and ASV alleviate OSA for opioid users, with higher failure rates observed in patients on CPAP in opioid users.

Obstructive Sleep Apnea and Incident Cancer: A Large Retrospective Multicenter Clinical Cohort Study.

BACKGROUND: To examine the association between the severity of obstructive sleep apnea (OSA) and nocturnal hypoxemia with incident cancer. METHODS: This was a multicenter retrospective clinical cohort study using linked clinical and provincial health administrative data on consecutive adults who underwent a diagnostic sleep study between 1994 and 2017 in four academic hospitals (Canada) who were free of cancer at baseline. Cancer status was derived from the Ontario Cancer Registry. Cox cause-specific regressions were utilized to address the objective and to calculate the 10-year absolute risk difference (ARD) in the marginal probability of incident cancer and the number needed to harm (NNH). RESULTS: Of 33,997 individuals considered, 33,711 with no missing OSA severity were included: median age, 50 years; 58% male; and 23% with severe OSA (apnea-hypopnea index >30). Of the 18,458 individuals with information on sleep time spent with oxygen saturation (SaO2) <90%, 5% spent >30% of sleep with SaO2 <90% (severe nocturnal hypoxemia). Over a median of 7 years, 2,498 of 33,711 (7%) individuals developed cancer, with an incidence rate of 10.3 (10.0-10.8) per 1,000 person-years. Controlling for confounders, severe OSA was associated with a 15% increased hazard of developing cancer compared with no OSA (HR = 1.15, 1.02-1.30; ARD = 1.28%, 0.20-2.37; and NNH = 78). Severe hypoxemia was associated with about 30% increased hazard (HR = 1.32, 1.08-1.61; ARD = 2.38%, 0.47-4.31; and NNH = 42). CONCLUSIONS: In a large cohort of individuals with suspected OSA free of cancer at baseline, the severity of OSA and nocturnal hypoxemia was independently associated with incident cancer. IMPACT: These findings suggest the need for more targeted cancer risk awareness in individuals with OSA.

The endoplasmic reticulum protein SEC22B interacts with NBEAL2 and is required for megakaryocyte α-granule biogenesis.

Studies of inherited platelet disorders have provided many insights into platelet development and function. Loss of function of neurobeachin-like 2 (NBEAL2) causes gray platelet syndrome (GPS), where the absence of platelet α-granules indicates NBEAL2 is required for their production by precursor megakaryocytes. The endoplasmic reticulum is a dynamic network that interacts with numerous intracellular vesicles and organelles and plays key roles in their development. The megakaryocyte endoplasmic reticulum is extensive, and in this study we investigated its role in the biogenesis of α-granules by focusing on the membrane-resident trafficking protein SEC22B. Coimmunoprecipitation (co-IP) experiments using tagged proteins expressed in human HEK293 and megakaryocytic immortalized megakaryocyte progenitor (imMKCL) cells established binding of NBEAL2 with SEC22B, and demonstrated that NBEAL2 can simultaneously bind SEC22B and P-selectin. NBEAL2-SEC22B binding was also observed for endogenous proteins in human megakaryocytes using co-IP, and immunofluorescence microscopy detected substantial overlap. SEC22B binding was localized to a region of NBEAL2 spanning amino acids 1798 to 1903, where 2 GPS-associated missense variants have been reported: E1833K and R1839C. NBEAL2 containing either variant did not bind SEC22B coexpressed in HEK293 cells. CRISPR/Cas9-mediated knockout of SEC22B in imMKCL cells resulted in decreased NBEAL2, but not vice versa. Loss of either SEC22B or NBEAL2 expression resulted in failure of α-granule production and reduced granule proteins in imMKCL cells. We conclude that SEC22B is required for α-granule biogenesis in megakaryocytes, and that interactions with SEC22B and P-selectin facilitate the essential role of NBEAL2 in granule development and cargo stability.

Cardiovascular consequences of obstructive sleep apnea in women: a historical cohort study.

OBJECTIVE/BACKGROUND: Evidence on sex differences in the association between obstructive sleep apnea (OSA) and cardiovascular outcomes is limited and controversial. We conducted a historical cohort study to investigate this relationship. PATIENTS/METHODS: Clinical data on adults who underwent sleep study at a large urban academic hospital (Toronto, Canada) between 1994 and 2010 were linked to provincial health administrative data from 1991 to 2015. We fit Cox regressions to investigate the association between OSA severity and a cardiovascular composite outcome (all-cause mortality or hospitalization due to myocardial infarction, stroke, heart failure or atrial fibrillation), controlling for risk factors and stratifying by sex. RESULTS: A total of 10,149 subjects were included: median age of 49 years, 38% women. Over a median of 9.3 years, 1782 (18%) participants developed an outcome. The association between percentage of sleep time spent with oxygen saturation <90% and outcome was stronger for women (HR for IQR, 3 vs 0% = 1.30, 1.19-1.42) than for men (HR for IQR = 1.13, 1.06-1.21) (p for interaction = 0.01) in the adjusted model. Stratifying by sex, oxygen desaturations and heart rate in sleep were significant predictors in both men and women, while presence of daytime sleepiness, sleep efficiency and periodic leg movements in sleep were predictive in women but not in men. CONCLUSIONS: In a large clinical cohort with suspected OSA, the impact of OSA as measured by the degree of nocturnal oxygen desaturation on the composite outcome was found to be greater in women than in men. We also found a different predictive ability of OSA-related factors by sex.

Learning how to learn: can embedded discussion boards help first-year students discover new learning strategies?

Learning anatomy and physiology at university can be challenging, as students need to understand both the language of the discipline and complex topics, such as system integration. Yet learning strategies are rarely taught at university, making it difficult for students to adopt new strategies, if their approach to learning has not been effective or efficient. This study evaluated the use of small-group peer discussion boards as an avenue for sharing learning strategies between students in a first-year anatomy and physiology course. The majority of students (91%) identified strategies from the discussion board worth trying before they completed the midsemester exam. The most frequently reported type of strategy was transforming records. By the end of semester, 76% of students had adopted at least one new strategy; however, these students performed significantly worse on the exam compared with students who did not adopt new strategies. The students who adopted new strategies learned about them from peers (33%), the discussion board (32%), or through self-discovery (32%). The majority of students (83%) found the discussion boards to be useful as a source of new learning strategies and for insight into how others learn. Although the discussion boards provided an avenue for students to learn about new strategies from each other, further guidance from instructors may be required to help students evaluate the effectiveness of these learning strategies.

Diverse pathogenetic roles of SOX genes in acute myeloid leukaemia and their therapeutic implications.

Acute myeloid leukaemia (AML) is a heterogeneous group of diseases with diverse pathogenetic pathways. When treated uniformly with conventional chemotherapy and allogeneic haematopoietic stem cell transplantation (HSCT), it showed variable clinical outcome and prognosis. Members of the SOX [Sry-related high-mobility group (HMG) box] gene family are involved in diverse embryonic and oncogenic processes. The roles of SOX genes in AML are not entirely clear but emerging evidence, including that arising from studies in solid-cancers, showed that SOX genes can function as tumour suppressors or oncogenes and may be involved in key pathogenetic pathways in AML involving C/EBPα mutations, activation of ß-catenin/Wnt and Hedgehog pathways and aberrant TP53 signals. Recent data based on genomics and proteomics have identified key interactions between SOX genes and partnering proteins of pathogenetic significance. The observations illustrated the principles and feasibilities of developing lead molecules of potential therapeutic values. Studying the diverse pathogenetic roles of SOX genes in AML may shed lights to the heterogeneity of AML and generate information that can be translated into novel therapeutic strategies.

Diffuse idiopathic skeletal hyperostosis masquerading as asthma: case report.

A 52-year-old man with a 10-year history of treatment-resistant asthma presented with repeated exacerbations over the course of 10 months. His symptoms were not responsive to salbutamol or inhaled corticosteroid agents, and he developed avascular necrosis of his left hip as a result of prolonged steroid therapy. Physical examination and radiography revealed signs consistent with diffuse idiopathic skeletal hyperostosis (DISH), including a C7-T1 osteophyte causing severe tracheal compression. The patient underwent C6-T1 anterior discectomy and fusion, and the compressive osteophyte was removed, which completely resolved his "asthma." Postoperative pulmonary function tests showed normalization of his FEV1/FVC ratio, and there was no airway reactivity on methacholine challenge. DISH is a systemic, noninflammatory condition characterized by ossification of spinal entheses, and it can present with respiratory disturbances due to airway compression by anterior cervical osteophytes. The authors present, to the best of their knowledge, the first documented case of asthma as a presentation of DISH.

Sleep and Pathological Wakefulness at the Time of Liberation from Mechanical Ventilation (SLEEWE). A Prospective Multicenter Physiological Study.

Rationale: Abnormal patterns of sleep and wakefulness exist in mechanically ventilated patients. Objectives: In this study (SLEEWE [Effect of Sleep Disruption on the Outcome of Weaning from Mechanical Ventilation]), we aimed to investigate polysomnographic indexes as well as a continuous index for evaluating sleep depth, the odds ratio product (ORP), to determine whether abnormal sleep or wakefulness is associated with the outcome of spontaneous breathing trials (SBTs). Methods: Mechanically ventilated patients from three sites were enrolled if an SBT was planned the following day. EEG was recorded using a portable sleep diagnostic device 15 hours before the SBT. The ORP was calculated from the power of four EEG frequency bands relative to each other, ranging from full wakefulness (2.5) to deep sleep (0). The correlation between the right and left hemispheres' ORP (R/L ORP) was calculated. Measurements and Main Results: Among 44 patients enrolled, 37 had technically adequate signals: 11 (30%) passed the SBT and were extubated, 8 (21%) passed the SBT but were not deemed to be clinically ready for extubation, and 18 (49%) failed the SBT. Pathological wakefulness or atypical sleep were highly prevalent, but the distribution of classical sleep stages was similar between groups. The mean ORP and the proportion of time in which the ORP was >2.2 were higher in extubated patients compared with the other groups (P < 0.05). R/L ORP was significantly lower in patients who failed the SBT, and the area under the receiver operating characteristic curve of R/L ORP to predict failure was 0.91 (95% confidence interval, 0.75-0.98). Conclusions: Patients who pass an SBT and are extubated reach higher levels of wakefulness as indicated by the ORP, suggesting abnormal wakefulness in others. The hemispheric ORP correlation is much poorer in patients who fail an SBT.

Cardiovascular Outcomes and All-Cause Mortality in Patients with Obstructive Sleep Apnea and Chronic Obstructive Pulmonary Disease (Overlap Syndrome).

RATIONALE: The combined impact of chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA) on cardiovascular outcomes remains controversial. OBJECTIVES: We determined whether the combined presence of COPD and severe OSA defined by the apnea-hypopnea index (AHI) or degree of nocturnal hypoxemia is associated with increased hazards of cardiovascular events and mortality. METHODS: Prospectively collected data from adults with suspected OSA who underwent sleep study between 1994 and 2010 were linked to provincial administrative data to determine a presence of COPD and composite outcome. Exposures of interest were: 1) AHI greater than 30, and 2) 10 or more minutes of sleep time spent with oxygen saturation (SaO2) less than 90%. The primary outcome was a composite of hospitalization due to myocardial infarction, stroke, congestive heart failure, cardiac revascularization procedures, or death from any cause. Using Cox regression and controlling for confounders, hazards were compared between four groups: AHI greater than 30 with COPD, AHI greater than 30 without COPD, AHI less than or equal to 30 with COPD, and AHI less than or equal to 30 without COPD (reference). A similar approach was used for the degree of nocturnal hypoxemia. Relative excess risk due to interaction (RERI) was calculated. To adjust for the effect of positive airway pressure treatment, given that information on its acceptance, but not adherence, was available, a separate analysis was conducted only on untreated individuals who never claimed a positive airway pressure device. RESULTS: Among 10,149 participants, 30% had AHI greater than 30, 25% spent at least 10 minutes of sleep with SaO2 less than 90%, and 12% had COPD. Over a median of 9.4 years, 16.4% developed an outcome. In the total sample, a greater hazard of outcome was observed in individuals with COPD who spent at least 10 minutes of sleep with SaO2 less than 90% (hazard ratio, 1.91; 95% confidence interval [CI], 1.60 to 2.28) but not with AHI greater than 30; a synergistic effect was found in women (RERI, 1.18; 95% CI, 0.05 to 2.30), but not men (RERI, -0.08; 95% CI, -0.47 to 0.32). The highest hazard of outcome was associated with the co-occurrence of AHI greater than 30 and COPD in untreated individuals (hazard ratio, 2.01; 95% CI, 1.55 to 2.62); a synergistic effect was not found. CONCLUSIONS: In adults with suspected OSA, the co-occurrence of nocturnal hypoxemia and COPD was associated with an increased hazard of cardiovascular events and mortality with a synergistic effect found only in women.

NBEAL2 (Neurobeachin-Like 2) Is Required for Retention of Cargo Proteins by α-Granules During Their Production by Megakaryocytes.

Objective- Human and mouse megakaryocytes lacking NBEAL2 (neurobeachin-like 2) produce platelets where α-granules lack protein cargo. This cargo is mostly megakaryocyte-synthesized, but some proteins, including FGN (fibrinogen), are endocytosed. In this study, we examined the trafficking of both types of cargo within primary megakaryocytes cultured from normal and NBEAL2-null mice, to determine the role of NBEAL2 in α-granule maturation. We also examined the interaction of NBEAL2 with the granule-associated protein P-selectin in human megakaryocytes and platelets. Approach and Results- Fluorescence microscopy was used to compare uptake of labeled FGN by normal and NBEAL2-null mouse megakaryocytes, which was similar in both. NBEAL2-null cells, however, showed decreased FGN retention, and studies with biotinylated protein showed rapid loss rather than increased degradation. Intracellular tracking via fluorescence microscopy revealed that in normal megakaryocytes, endocytosed FGN sequentially associated with compartments expressing RAB5 (Ras-related protein in brain 5), RAB7 (Ras-related protein in brain 7), and P-selectin, where it was retained. A similar initial pattern was observed in NBEAL2-null megakaryocytes, but then FGN passed from the P-selectin compartment to RAB11 (Ras-related protein in brain 11)-associated endosomes before release. Megakaryocyte-synthesized VWF (Von Willebrand factor) was observed to follow the same route out of NBEAL2-null cells. Immunofluorescence microscopy revealed intracellular colocalization of NBEAL2 with P-selectin in human megakaryocytes, proplatelets, and platelets. Native NBEAL2 and P-selectin were coimmunoprecipitated from platelets and megakaryocytes. Conclusions- NBEAL2 is not required for FGN uptake by megakaryocytes. NBEAL2 is required for the retention of both endocytosed and megakaryocyte-synthesized proteins by maturing α-granules, and possibly by platelet-borne granules. This function may involve interaction of NBEAL2 with P-selectin.

Sleep Apnea Increases the Risk of New Hospitalized Atrial Fibrillation: A Historical Cohort Study.

OBJECTIVES: This study examined the relationship between newly diagnosed OSA and incident hospitalized atrial fibrillation (AF) over the subsequent 10 years in a large arrhythmia-free cohort. METHODS: Adults referred between 1994 and 2010 to a large academic hospital with suspected OSA who were arrhythmia-free at the time of the first diagnostic sleep study were included. Clinical data were linked to provincial health administrative data to define outcome. Cox regressions were used to investigate the relationship between severity of OSA as measured by the apnea-hypopnea index (AHI) and degree of nocturnal hypoxemia, and incident hospitalized AF. RESULTS: In total, 8,256 subjects were included in this study. Their median age was 47 years, 62% were men; 28% had an AHI > 30 events per hour, and 6% spent > 30% of sleep time with oxygen saturation < 90%. Over a median follow-up of 10 years (interquartile range, 7-13 years), 173 participants (2.1%) were hospitalized with AF. Controlling for age, sex, alcohol consumption, smoking status, previous heart failure, COPD, and pulmonary embolism, nocturnal hypoxemia (but not AHI) was a significant predictor of incident AF: hazard ratio, 2.47 (95% CI, 1.64-3.71). After further controlling for BMI and hypertension, this association was attenuated but remained significant (hazard ratio, 1.77 [95% CI, 1.15-2.74]). CONCLUSIONS: In a large arrhythmia-free clinical cohort with suspected OSA, nocturnal hypoxemia was independently associated with a 77% increased hazard of incident hospitalized AF. These findings further support a relationship between OSA, nocturnal hypoxemia, and new-onset AF, and they may be used to enhance AF prevention in patients with OSA and severe nocturnal hypoxemia.

High sensitivity 8-color flow cytometry assay for paroxysmal nocturnal hemoglobinuria granulocyte and monocyte detections.

Flow cytometry is the gold standard in diagnosis of paroxysmal nocturnal hemoglobinuria (PNH) by detecting the absence of glycol-phosphatidyl inositol (GPI)-linked protein expression on granulocyte and monocyte surfaces. However, the current assays are not optimized and require improvement, particularly in reducing background fluorescence and optimizing sensitivity and specificity. With more fluorochromes available and with advances in instrument engineering, rare populations may be identified with high sensitivity. The present study assessed an 8-color combination of comprehensive GPI-linked markers, namely fluorescein-labeled proaerolysin (FLAER), cluster of differentiation 157 (CD157), CD24 and CD14, and the lineage markers for granulocyte (CD15) and monocyte (CD64) cells to detect PNH clones. Additionally, to optimize the PNH flow assay, a 'dump' channel was used, comprised of CD5 and CD19, to exclude non-specific binding in order to reduce background. This method aimed to improve sensitivity and reduce the background to create an optimized PNH flow cocktail. The results demonstrated that the current 4-color PNH combination identifies a CD55- and FLAER+ population that is not PNH clones. By contrast, the 8-color panel delineated PNH clones from both monocyte and granulocytes by using granulocyte antigen (CD15) and monocyte antigen (CD64) as a gating strategy. The sensitivity was 0.01% for granulocytes and 0.05% for monocytes with an acquisition of 100,000 monocyte and granulocyte events. The background on a normal whole blood sample was 0.00076% on monocytes and 0.00277% on granulocytes. Thus, overall, the 8-color PNH assay exhibited high levels of specificity and sensitivity. The 8-color combination facilitated the improvement and enhancement of sensitivity in PNH clone identification, and may provide a useful tool for pathologists in PNH diagnosis and for monitoring patients at risk of developing classical/hemolytic PNH, to enable treatment to be delivered promptly.

Distinct Patterns of Hyperpnea During Cheyne-Stokes Respiration: Implication for Cardiac Function in Patients With Heart Failure.

STUDY OBJECTIVES: In heart failure (HF), we observed two patterns of hyperpnea during Cheyne-Stokes respiration with central sleep apnea (CSR-CSA): a positive pattern where end-expiratory lung volume remains at or above functional residual capacity, and a negative pattern where it falls below functional residual capacity. We hypothesized the negative pattern is associated with worse HF. METHODS: Patients with HF underwent polysomnography. During CSR-CSA, hyperpnea, apnea-hyperpnea cycle, and lung to finger circulation times (LFCT) were measured. Plasma N-terminal prohormone of brain natriuretic peptide (NT-proBNP) concentration and left ventricular ejection fraction (LVEF) were assessed. RESULTS: Of 33 patients with CSR-CSA (31 men, mean age 68 years), 9 had a negative hyperpnea pattern. There was no difference in age, body mass index, and apnea-hypopnea index between groups. Patients with a negative pattern had longer hyperpnea time (39.5 ± 6.4 versus 25.8 ± 5.9 seconds, P < .01), longer cycle time (67.8 ± 15.9 versus 51.7 ± 9.9 seconds, P < .01), higher NT-proBNP concentrations (2740 [6769] versus 570 [864] pg/ml, P = .01), and worse New York Heart Association class (P = .02) than those with a positive pattern. LFCT and LVEF did not differ between groups. CONCLUSIONS: Patients with HF and a negative CSR-CSA pattern have evidence of worse cardiac function than those with a positive pattern. Greater positive expiratory pressure during hyperpnea is likely generated during the negative pattern and might support stroke volume in patients with worse cardiac function. COMMENTARY: A commentary on this article appears in this issue on page 1227. CLINICAL TRIAL REGISTRATION: The trial is registered with Current Controlled Trials (www.controlled-trials.com; ISRCTN67500535) and Clinical Trials (www.clinicaltrials.gov; NCT01128816).

Obstructive sleep apnoea is not a risk factor for incident hospitalised depression: a historical cohort study.

We evaluated whether obstructive sleep apnoea (OSA) was related to the incidence of hospitalisation for depression, a robust end-point that is unlikely to result from misdiagnosis.All adults referred with suspected OSA who underwent a diagnostic sleep study at a large urban academic hospital between 1994 and 2010 and were linked to provincial health administrative data between 1991 and 2015 were included. Cox regression analysis was used to investigate the association between OSA symptoms and severity and incident hospitalised depression, the primary outcome.Over a median follow-up of 9.7 years, 136 (1.3%) out of 10 149 participants were hospitalised for depression. A significant crude effect of OSA symptoms (waking unrefreshed and impact on memory and concentration) on hospitalised depression became nonsignificant after controlling for confounders. Apnoea-hypopnoea index was not significantly associated with the outcome: adjusted hazard ratio (33 versus 6 events·h-1) 1.13 (95% CI 0.91-1.40). Factors associated with hospitalised depression were female sex, younger age, use of hypnotics, alcoholism and unemployment.In a large clinical cohort with suspected OSA, controlling for confounders, OSA symptoms and severity were not related to the risk of hospitalisation for depression, suggesting that previously reported links between OSA and depression may be due to overlapping diagnostic criteria. However, our findings cannot exclude a potential link between OSA and milder depression.