Mitochondrial DNA alteration in obstructive sleep apnea.

BACKGROUND: Obstructive Sleep Apnea (OSAS) is a disease associated with the increase of cardiovascular risk and it is characterized by repeated episodes of Intermittent Hypoxia (IH) which inducing oxidative stress and systemic inflammation. Mitochondria are cell organelles involved in the respiratory that have their own DNA (MtDNA). The aim of this study was to investigate if the increase of oxidative stress in OSAS patients can induce also MtDNA alterations. METHODS: 46 OSAS patients (age 59.27 ± 11.38; BMI 30.84 ± 3.64; AHI 36.63 ± 24.18) were compared with 36 control subjects (age 54.42 ± 6.63; BMI 29.06 ± 4.7; AHI 3.8 ± 1.10). In blood cells Content of MtDNA and nuclear DNA (nDNA) was measured in OSAS patients by Real Time PCR. The ratio between MtDNA/nDNA was then calculated. Presence of oxidative stress was evaluated by levels of Reactive Oxygen Metabolites (ROMs), measured by diacron reactive oxygen metabolite test (d-ROM test). RESULTS: MtDNA/nDNA was higher in patients with OSAS than in the control group (150.94 ± 49.14 vs 128.96 ± 45.8; p = 0.04), the levels of ROMs were also higher in OSAS subjects (329.71 ± 70.17 vs 226 ± 36.76; p = 0.04) and they were positively correlated with MtDNA/nDNA (R = 0.5, p < 0.01). CONCLUSIONS: In OSAS patients there is a Mitochondrial DNA damage induced by the increase of oxidative stress. Intermittent hypoxia seems to be the main mechanism which leads to this process.

Efficacy and safety of EBUS-TBNA under conscious sedation with meperidine and midazolam.

BACKGROUND: According to the guidelines, endobronchial ultrasound guided transbronchial needle aspiration (EBUS-TBNA) is the technique of choice for the diagnosis of mediastinal involvement in lung cancer; it is also useful for other mediastinal malignancies and benign pathology. Nevertheless, there is still discussion about whether to perform it under general anesthesia or under conscious sedation. METHODS: We retrospectively analyzed the data of all patients who underwent EBUS-TBNA under conscious sedation with up to 1 mg/kg of meperidine and up to 0.15 mg/kg of midazolam in the Interventional Pulmonology Unit of the Azienda USL-IRCCS Santa Maria Nuova of Reggio Emilia during 2 consecutive years. Demographic data, indication for the procedure, duration, number of lymph node sampled, number of passes per station, diagnostic yield, drugs dosage, questionnaire score, and complications were collected. RESULTS: A total of 302 patients underwent EBUS-TBNA, and 68% of the patients were males and the mean age was 65 ± 13 years old. The average duration of procedures was 24.4 minutes and the mean dosage of drugs was 4.32 ± 1.52 mg for midazolam and 50.86 ± 13.71 mg for meperidine. The mean number of lymph nodes sampled per patient was 1.75 ± 0.82, and each patient received an average of 4.71 ± 1.78 passes. A total of 90.7% of patients completed the procedures, 85% had adequate samples, and 94.4% of patients declared with Likert's questionnaire that they strongly agree to repeat the test if necessary. CONCLUSION: EBUS-TBNA performed under conscious sedation with meperidine and midazolam is feasible and well-tolerated and has a similar diagnostic yield of that reported in literature.

A case of chronic eosinophilic pneumonia in a patient treated with dupilumab.

The increasing knowledge on inflammatory pathways has driven the development of targeted biological therapies for severe refractory asthma. Among the recently developed biologics, the fully human monoclonal antibody dupilumab is an interesting therapeutic option, given its ability to inhibit the biological effects of both IL-4 and IL-13. We describe the case of a male, Caucasian, 56-year-old patient with allergic and eosinophilic severe asthma. Given the poor asthma control, he started treatment with add-on dupilumab, and after the tenth injection, he presented with a fever and bilateral pulmonary thickening. A significant increase in blood eosinophilia was also reported. The patient underwent a fiberoptic bronchoscopy with bronchoalveolar lavage (BAL) and transbronchial lung biopsy (TBLB/TBB). BAL revealed eosinophils alveolitis (60%) while TBB showed findings compatible with chronic eosinophilic pneumonia (CEP). After prolonged treatment with oral corticosteroids, the clinical picture improved with resolution of CEP. Since the beginning of dupilumab treatment, simultaneously to a great improvement in asthma control, the patient showed a progressive increase in blood eosinophils count and subsequent onset of clinical-radiological pattern suggestive of CEP. Based on published data, dupilumab may have induced an alteration of the complex immunological pathway of our patient. This pathway is affected by both allergic and eosinophilic asthmatic endotypes, and consequently, the concomitant action of allergenic stimuli and eosinophils may have caused the appearance of eosinophilic pneumonia. To our knowledge, this is the first reported case of CEP as a possible severe side effect of dupilumab administration.

Prevalence of comorbidities in patients with obstructive sleep apnea syndrome, overlap syndrome and obesity hypoventilation syndrome.

INTRODUCTION: Sleep-disordered breathing causes a burden to the sufferer, the health care system and the society. Most studies have focused on obstructive sleep apnea (OSA); however, the prevalence of comorbidities in patients affected by overlap syndrome (OS) and obesity hypoventilation syndrome (OHS) has not been carefully evaluated. STUDY OBJECTIVES: The principal aim of this study was to identify the presence of comorbidities in patients suffering from OSA, OS, OHS and the differences in three groups of patients. Another purpose was to verify if sleepiness is associated with a greater prevalence of comorbidities. METHODS: A retrospective analysis in 989 adults referred for sleep diagnostic testing to our sleep center was performed. Patients were classified in OSA (721), OS (123) and OHS (145). RESULTS: The prevalence of comorbidities was higher in patients affected by OS and was the highest in the OHS group, while the prevalence of arterial hypertension is the highest in patients affected by OS. The probability of having more than two comorbidities follows the same trend. Excessive daytime sleepiness was associated with an increased rate of arterial hypertension, diabetes mellitus and the presence of multimorbidity in each group of patients. CONCLUSIONS: The presence and the association of comorbidities seem to be higher in patients suffering from OSA, OS and OHS. Subjects suffering of OHS present a high prevalence of main diseases despite their younger age compared with others patients with SDB. Sleepiness may have a role, at least in a subset of these patients, into the development of comorbidities.