Treatment with AM3 restores defective T-cell function in COPD patients.

BACKGROUND: Lymphocyte alterations have been associated with an increased prevalence of acute respiratory infections in COPD patients. AM3 is an oral immunomodulator that normalizes the defective functions of peripheral blood natural killer and phagocytic cells in COPD patients and improves their health-related quality of life. OBJECTIVES: To characterize putative systemic abnormalities of the T-cell compartment in COPD patients, and to investigate whether AM3 can restore such abnormalities. DESIGN: The study was a randomized, prospective, double-blind, placebo-controlled trial in a cohort of COPD patients. The results were also compared to those of nonsmoker and ex-smoker healthy control subjects. SETTING: Outpatient departments of four hospitals. PATIENTS: Seventy COPD patients were randomized to receive either AM3 or a placebo orally for 90 consecutive days. Populations of 36 healthy nonsmokers and 36 healthy ex-smokers were used as control subjects. MEASUREMENTS: Peripheral blood mononuclear cell (PBMC) proliferation and production of interleukin (IL)-2, IL-4, IL-12p40, tumor necrosis factor-alpha, and interferon (IFN)-gamma proteins in response to the T-cell polyclonal mitogens were assessed at baseline and at the end of treatment. RESULTS: The proliferative response was significantly decreased in COPD patients. Decreased production of IFN-gamma was the only defect in the profiles of the cytokine measures, and was selectively observed in COPD patients, but not in nonsmoker and ex-smoker healthy control subjects. Treatment with AM3 significantly restored the PBMC proliferative response to polyclonal mitogens and significantly promoted stimulated IFN-gamma production in these patients. The normalization of these proliferative responses was not related to significant variations in the numbers of peripheral blood monocytes, CD3+, CD4+, CD8+ cells or of any major naïve/memory/activated T-cell subset. The increased IFN-gamma production in the AM3 study arm was associated with an increase in the mean of number of IFN-gamma molecules produced per CD8+ T cells. CONCLUSIONS: PBMCs of COPD patients showed clear functional T-lymphocyte abnormalities that are rescued by AM3 treatment.

Prevalence of symptoms and risk of sleep apnea in primary care.

BACKGROUND: To obtain prevalence estimates for key symptoms and features that can indicate the presence of obstructive sleep apnea (OSA) in a broad range of primary care settings. DESIGN: Cross-sectional survey. SETTING: Forty offices and clinics in the United States, Germany, and Spain. PARTICIPANTS: Consecutive patients who were > 15 years of age, regardless of the reason for the visit. MEASUREMENTS: We collected demographic information, prevalence of self-reported chronic snoring, sleepiness, obesity (body mass index [BMI] > 30), hypertension, and calculation of OSA risk, and we also compared results between the United States and Europe. RESULTS: There was a 78% return rate for 8,000 surveys (mean age, 51 years; age range, 15 to 98 years; 52% women). One third of participants (32%) had a high pretest probability for OSA, with a higher rate in the United States (35.8% of 3,915 participants) than in Europe (26.3% of 2,308 participants; p < 0.001; age-matched and sex-adjusted odds ratio [OR], 1.37; 95% confidence interval [CI], 1.16 to 1.61). Sleepiness (32.4% vs 11.8%, respectively; p < 0.001) followed by obesity and/or hypertension (44.8% vs 37.1%, respectively; p < 0.01) contributed to the OSA risk difference between participants in the United States and Europe, as frequent snoring and breathing pauses were similarly reported (44%). A high pretest probability for OSA was more often present in men than in women (37.9% vs 27.8%, respectively; p < 0.005; OR, 1.96; CI, 1.59 to 2.88) and in those that were obese (ie, BMI, > or = 30 kg/m(2)), a condition that is generally more common in the US population than in the European population (27.9% vs 17.2%, respectively; p < 0.01). CONCLUSIONS: Primary care physicians in the United States and Europe will encounter a high demand for services to confirm or manage sleep apnea, sleepiness, and obesity.

Sleep disordered breathing and COPD.

This issue of Sleep and Breathing presents a section on sleep in COPD, a widespread disease consuming many health resources which is often diagnosed so late that little chance of reversibility remains. The early detection of the warning clinical signs can include sleep studies, mainly in the presence of arterial carbon dioxide levels higher than expected from pulmonary function tests. Two of the articles deal with hypercapnia and nocturnal hypoventilation in COPD; the third underlines the impact of tobacco smoking on snoring and on oxygen availability to tissues, showing a poor reliability of pulse oximetry in subjects with heavy smoking habits.

Long-term effects of treatment with nasal continuous positive airway pressure on lung function in patients with overlap syndrome.

We assessed the effects of chronic nasal continuous positive airway pressure (CPAP) therapy on lung function in a series of unselected patients with overlap syndrome, and we determined whether there were differences in the response induced by CPAP between hypercapnic (PaCO2 > or =45 mm Hg) and eucapnic patients with overlap syndrome. The study population included 55 unselected patients (48 men, mean age of 58.5 +/- 10.5 years) with a concurrent diagnosis of chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea-hypopnea syndrome (OSAHS) who had been referred to the Department of Pulmonology of our hospital over 2 consecutive years and in whom work-up studies resulted in the prescription of nasal CPAP therapy. An apnea-hypopnea index (AHI) greater than or equal to 10 in the cardiorespiratory polygraphy was required for the diagnosis of OSAHS. A forced expiratory volume in one second (FEV1) less than 80% and FEV1-forced vital capacity (FVC) ratio less than 70% of the reference values were required for the diagnosis of COPD. Control lung function studies and arterial blood gas measurements were performed at 6 and 18 months of CPAP therapy. These patients with overlap syndrome accounted for 28.5% of all patients with OSAHS treated with CPAP during the study period. The mean AHI was 37.3 +/- 26.1 and the mean CPAP level 7.3 +/- 1.3 cm H2O. Thirty-three patients were hypercapnic (PaCO2 > or = 45 mm Hg) and 22 eucapnic. The hypercapnic group had higher AHI value (44.3 +/- 26.9) than the eucapnic group (28.6 +/- 21.9) (P < 0.05). After 6 months of CPAP therapy, there were statistically significant increases in PaO2, FEV1, and FVC, accompanied by significant decreases in PaCO2, serum bicarbonate levels, and alveolar-arterial oxygen difference. Response of overlap syndrome patients to CPAP therapy was superior in the hypercapnic group, particularly in relation to improvement of arterial blood gases. However, statistically significant differences in all parameters for the comparison between 6 and 18 months were not recorded.