Fas-positive lymphocytes are associated with systemic inflammation in obstructive sleep apnea syndrome

Systemic Inflammatory Status of Patients with Obstructive Sleep Apnea Syndrome and the Predictive Value of Heparin-Binding Protein

Objective: To investigate the alteration of the systemic inflammatory status of patients with obstructive sleep apnea syndrome (OSAS) and the predictive value of heparin-binding protein (HBP) for OSAS. Methods: Patients with OSAS who were hospitalized in our hospital from 2020 January to 2022 December and diagnosed by polysomnography (PSG) (OSAS group, n = 79) were retrospectively studied and their relevant examination findings and demographic characteristics were recorded. Sex- and age-matched non-OSAS patients hospitalized at the same time were selected as the control group (control group, n = 28). Differences in peripheral blood neutrophil counts, lymphocyte counts, neutrophil-to-lymphocyte ratio (NLR), procalcitonin (PCT), and HBP were compared between the 2 groups. The predictive value of these markers for OSAS was analyzed using the receiver operating characteristic curve, and independent risk factors for OSAS were determined using logistic regression analysis. Peripheral blood was drawn from all patients in the fasting state of the morning. Results: The number of peripheral blood neutrophils, lymphocytes, and HBP was higher in the OSAS group than in the control group, and the differences were statistically significant (P all <.05), while the differences in NLR and PCT between the 2 groups were not statistically significant (P all >.05). Plasma HBP level had an area under the curve (AUC) of 0.79 (P < .0001) in determining OSAS, with a sensitivity of 80.49% and a specificity of 70.83% and the best cutoff value was >10.73 ng/ml. Combining body mass index (BMI), neutrophil, lymphocyte, and HBP improved the predictive value of OSAS with an AUC of 0.89 (P < .0001), a sensitivity of 80.49%, and a specificity of 87.50%. Logistic regression analysis showed that both BMI and HBP were independent risk factors for OSAS (PBMI < .001, PHBP < .01), while neutrophils and lymphocytes were not (P all >.05). Conclusions: This is the first study to objectively examine HBP in OSAS patients, and HBP is an independent risk factor that may serve as a diagnostic biomarker in OSAS. Patients with OSAS have an altered systemic inflammatory state and may be more prone to severe bacterial infections.

Chronic Breathlessness in Obstructive Sleep Apnea and the Use of Lymphocyte Parameters to Identify Overlap Syndrome among Patients

Little is known about the distribution of etiology in obstructive sleep apnea (OSA) combined with chronic breathlessness. A significant portion of patients in this group have so-called "overlap syndrome (OVS)", characterized by chronic obstructive pulmonary disease (COPD). OVS has more complications and a poorer prognosis compared to patients with either OSA or COPD alone, which makes it important to identify OVS early in OSA. The current study was a retrospective cross-sectional analysis of consecutive adult patients who were diagnosed with OSA (n = 1062), of whom 275 were hospitalized due to chronic breathlessness. Respiratory and cardiac diseases accounted for the vast majority of causes, followed by gastrointestinal and renal disorders. The final study population comprised 115 patients with OSA alone (n = 64) and OVS (n = 51), who had chronic breathlessness as the primary complaint, not secondary as one of many other complaints. Lymphocytes, CD4 counts, neutrophil-to-lymphocyte ratio (NLR), and PLR were differently expressed between the OSA-alone group and OVS group. The NLR, lymphocytes, and CD4 counts had a moderate diagnostic value for OVS in OSA patients, with AUCs of 0.708 (95% CI, 0.614-0.802), 0.719 (95% CI, 0.624-0.813), and 0.744 (95% CI, 0.653-0.834), respectively. The NLR had the highest AUC for predicting a 6-month re-admission of OVS, with a cut-off of 3.567 and a moderate prognostic value. The sensitivity and specificity were 0.8 and 0.732, respectively. In the animal model, the spleen hematoxylin- and eosin-stained, electron microscopy images showed germinal-center damage, chromatin activation, and mitochondrial swelling under the overlapping effect of intermittent hypoxia and cigarette smoke exposure. OSA with chronic breathlessness cannot be overstated. A significant proportion of patients with COPD in this group had poor lung function at initial diagnosis. The NLR is a useful biomarker to differentiate OVS among OSA patients combined with chronic breathlessness.

Redistribution of Monocyte Subsets in Obstructive Sleep Apnea Syndrome Patients Leads to an Imbalanced PD-1/PD-L1 Cross-Talk with CD4/CD8 T Cells

Obstructive sleep apnea syndrome (OSAS) represents a substantial disease of recurrent sleep fragmentation, leading to intermittent hypoxia and subsequent diseases such as cardiovascular, metabolic, or cognitive dysfunctions. In addition, OSAS is considered as low-grade systemic inflammation, which is associated with a higher incidence of cancer, severity of infections, and an overall immune dysregulation. This research project aims to comprehensively investigate the interplay of wholesome sleep and the immune functions of circulating monocytes and T cells in OSAS patients, which are known to be affected by oxidative stress. We studied the distribution of the CD14/CD16 characterized monocyte subsets in peripheral blood as well as their PD-L1 expression and complex formation with T cells. Furthermore, a detailed analysis of T cell subsets with regard to their PD-1 and PD-L1 expression was performed. Data revealed a decrease of classical monocytes accompanied by an increase of both CD16⁺ monocyte subsets in OSAS patients that was positively correlated with the body mass index. OSAS patients revealed an increased PD-1 and PD-L1 expression in T cells and monocytes, respectively, which was linked to the severity of monocyte subset alterations. The complex formation of monocytes and T cells was also elevated in OSAS patients, which indicates a deregulated PD-1/PD-L1 cross-talk between these cells. Our data show for the first time, to our knowledge, massive alterations of peripheral monocyte subsets in response to OSAS and its accompanying phenomena.

The Bronchiectasis in COPD-OSA Overlap Syndrome Patients

Purpose

COPD-OSA (chronic obstructive pulmonary disease–obstructive sleep apnea) overlap syndrome is associated with more frequent COPD acute exacerbations than COPD without OSA. With the application of high-resolution computed tomography (HRCT) in COPD, bronchiectasis is commonly detected and is associated with disease severity. Sleep respiratory disease is also associated with bronchiectasis; however, the correlation between OSA and coexisted bronchiectasis in COPD (COPD-Bx) has not been reported yet.

Patients and Methods

A total of 124 consecutive patients with stable COPD were enrolled. All subjects completed the chest HRCT and nocturnal polysomnography (PSG). The scores of extent and severity in bronchiectasis were assessed based on the Smith method and the Bhalla scoring system. Clinical data, questionnaire, routine blood test data, blood levels of C-reactive protein (CRP) and Immunoglobulin E, and the lymphocyte subtype were collected.

Results

Among all enrolled patients, 56.45% (70/124) were diagnosed as COPD-OSA based on the results of PSG screening. Bronchiectasis was detected in 42.86% (30/70) of the patients with COPD-OSA, but in 18.52% (10/54) of the patients without OSA (χ2=8.264, p=0.004). PSG screening revealed that COPD with OSA had a significantly higher apnea-hypopnea index and percent of time spent with oxygen saturation below 90% (T90). Higher values of CRP, T90, and lower CD4/CD8 in the COPD-Bx with OSA were detected compared to COPD-Bx without OSA. Correlation analysis showed that the Bhalla severity score was related to CD8 cell count (r=0.446, p<0.05) and CD4/CD8 (r=−0.357, p<0.05) in all the COPD-Bx patients. The Smith extent score was also associated with the values of CD8 count (r=0.388, p<0.05) and CD4/CD8 (r=−0.381, p<0.05).

Conclusion

The comorbid bronchiectasis was more common in COPD-OSA overlap syndrome patient and may be related to more severe hypoxia and increased systemic inflammation.

Ocular surface assessment and morphological alterations in meibomian glands with meibography in obstructive sleep apnea Syndrome

PURPOSE

To evaluate ocular surface and Meibomian glands morphology of patients with obstructive sleep apnea syndrome (OSAS).

MATERIALS AND METHODS

Based on polysomnography, 36 eyes of 36 patients with severe OSAS (Group 1, apnea-hypopnea index (AHI) ≥30/h) and 24 eyes of 24 patients with primary snoring or mild OSAS (Group 2, AHI<15/h) were enrolled. Detailed eye examination along with ocular surface staining (fluorescein, 2%) according to Oxford scale, tear film break-up time (t-BUT), Schirmer 1 test, ocular surface disease index (OSDI) scoring, and evaluation of upper and lower eyelid Meibomian glands using infrared filter of slit-lamp biomicroscope were performed. In addition to grading Meibomian gland drop-out, the presence morphologic alterations such as Meibomian gland duct distortion, thinning and dilatation were also assessed.

RESULTS

The mean ages were 50.8 ± 8.3 (range, 35-68) and 47.9 ± 10.5 (range, 27-69) in Group 1 and Group 2, respectively (p = 0.616). Best-corrected visual acuity, Schirmer 1 test, Oxford scale and OSDI scores, and lower meiboscores did not differ significantly between groups. In Group 1, average t-BUT was lower (p = 0.003), upper and total (upper + lower) meiboscores were higher as compared to Group 2 (p < 0.05). The frequency of Meibomian gland duct distortion, thinning and dilatation were also significantly greater in Group 1 (p < 0.05).

CONCLUSION

Morphological changes, in addition to Meibomian glands dropout were significant in severe OSAS patients as demonstrated objectively with meibography. Schirmer 1 and t-BUT tests were in favor of evaporative type dry eye syndrome, which also support Meibomian gland alterations in severe OSAS patients.