A case of severe allergic eosinophilic asthma with nasal polyposis in a patient affected by Birt-Hogg-Dubè syndrome successfully treated with benralizumab

Summary

Birt-Hogg-Dubè (BHD) syndrome is a rare genetic pathology characterized by cutaneous fibrofolliculomas, pulmonary cysts and kidney tumours. Severe asthma is the most serious form of asthma that does not respond to standard treatments. We present the case of a 68 years-old male patient who had frequent respiratory tract infections, shortness of breath and decline in lung function, nasal polyposis and hypertrophy of the nasal turbinates, for this reason was treated as a severe asthmatic patient for several years with ICS + LABA and high doses of OCS. When we tried to reduce OCS the patient had worsening of the symptoms, we requested a HRTC scan that showed presence of several cysts spread ubiquitously. The patient had a family history of pneumothorax, for this reason we requested a genetic test that resulted in a heterozygous point mutation on exon 12 (c.1429 C > T) of FLCN gene. Despite the diagnosis of BHD syndrome, the patient's clinical condition kept on suggesting an underlying severe asthma and the blood tests we requested pointed out a high percentage of eosinophils, for this reason we opted for the administration of benralizumab that resulted in an excellent asthma control and increased quality of life.

Tocilizumab and liver injury in patients with COVID-19

Current mortality rate in patients with COVID-19 disease is about 2%, whereas 5% of patients require admission to the intensive care unit. It is assumed that interleukin (IL)-6 may be involved in the pathogenesis of severe COVID-19 infections; therefore, in the absence of a specific antiviral therapy, some authors have suggested that tocilizumab - a drug used to block the signal transduction pathway of IL-6 - could have beneficial effects in the management of severe COVID-19 disease. However, mild-to-moderate elevation in transaminases and drug-induced liver injury have been observed in patients treated with tocilizumab. We present seven cases of patients with elevated liver enzymes [up to five times the upper limit of normal (ULN)] at baseline who received tocilizumab for life-threatening COVID-19 disease. All patients had no history of liver or pulmonary disease and were admitted for acute hypoxemic respiratory failure, dyspnea and fever due to COVID-19 bilateral pneumonia. IL-6 was available in six patients, and was significantly increased particularly in those with severe impairment of lung function. All patients received tocilizumab (8 mg/kg/day) for two consecutive days because of lack of improvement after hydroxychloroquine, azithromycin and lopinavir/ritonavir treatment. After tocilizumab administration, clinical condition rapidly improved and liver function test normalized within 3 weeks of treatment. Tocilizumab may be effective for the treatment of severe COVID-19 disease, even in patients with elevated liver function tests. Further studies are needed to evaluate the impact of tocilizumab use on liver function tests in patients with pre-existing chronic liver disease.

Interleukin-6 is Increased in Breath Condensate of Patients with Non-Small Cell Lung Cancer

Despite recent advances in the diagnosis and treatment of non-small cell lung cancer (NSCLC), most patients still present with advanced stage disease at the time of diagnosis. Recent studies suggest that IL-6 is involved in the development of lung cancer. The aim of the present study was to investigate whether the measurement of IL-6 levels in the breath condensate of NSCLC patients could be used to bring forward the moment of diagnosis and to monitor the progression of the disease. Twenty patients with histological evidence of NSCLC (14 men and 6 women, age 63±8 years) and 15 healthy controls (8 men and 7 women, age 45±6 years) were enrolled in the study. IL6 was measured in the exhaled breath condensate of patients and controls by means of a specific enzyme immunoassay kit. Higher concentrations of exhaled IL-6 were found in NSCLC patients (9.6±0.3 pg/mL) than in controls (3.5±0.2 pg/mL). A statistically significant difference was observed between patients with NSCLC at different stages: higher concentrations of IL-6 (10.9±0.5 pg/mL) were found in patients with metastatic disease than in those with stage III (9.7±0.4 pg/mL), stage II (8.9±0.3 pg/mL) and stage I disease (7.9±0.3 pg/mL). These findings suggest that the measurement of IL-6 in the breath condensate of patients with NSCLC could be proposed as a parameter to take into account in early diagnosis and disease monitoring.

Expression profiling of miRNA-145 and miRNA-338 in serum and sputum of patients with COPD, asthma, and asthma-COPD overlap syndrome phenotype

Background and objectives

A new phenotype with overlapping characteristics between asthma and chronic obstructive pulmonary disease (COPD) called asthma–COPD overlap syndrome (ACOS) is emerging among inflammation diseases. To date, there is no agreement on specific criteria to define this syndrome, and the current guidelines are insufficient to classify the analogy and differences between overlap and COPD or asthma phenotypes. It would be necessary to identify new biomarkers able to identify these diseases clearly. Thus, the aim of this study was to identify a serum and supernatant of sputum microRNA (miRNA) expression profile of miRNA-145 and miRNA-338 in patients with asthma (n=13), COPD (n=31), and ACOS (n=8) and controls (n=7).

Methods

The expression was evaluated using quantitative real-time polymerase chain reaction (qRT-PCR). For statistical analysis, the ANOVA test, Kruskal–Wallis test, Mann–Whitney U-test, and Spearman’s rank correlation were used.

Results

The main finding of this work is that the expression of miRNA-338 is higher in the supernatant of different obstructive diseases than in peripheral blood, while miRNA-145 is higher only in the supernatant of asthma patients. The expression of both selected miRNAs is higher in the supernatant of asthma and COPD patients than in controls.

Conclusion

Differences in sputum miRNA expression profile were observed between patients with ACOS and asthma or COPD, which underline the potential role of miRNA as a biomarker that is able to discriminate patients with ACOS, asthma, and COPD.

Exhaled breath temperature measurement: influence of circadian rhythm

Exhaled breath temperature (EBT) is an expression of airway inflammation, an event that drives several lung diseases. The measurement of the exhaled breath temperature has recently been proposed as a popular tool in the diagnosis and monitoring of inflammatory lung diseases due to the fact that it is a non-invasive method. The influence of external factors on EBT, its reproducibility, and its sensitivity to treatment have already been explored. However, to reach clinical practice, EBT requires a complete validation that is still lacking. The aim of this study was to analyse the possible influence of an important internal variable, i.e the circadian rhythm on EBT values in a group of 24 healthy adult volunteers. We repeated measurement of EBT at different hours of the day: 8.00 AM, 12.00 AM, 4.00 PM, 8.00 PM and analysed the correlation with axillary temperature measurement at these times. The EBT resulted significantly different during daily measurements (8.00 AM vs 12.00 AM vs 4.00 PM vs 8.00 PM: 28.01±1.64°C vs 28.8±1.82°C vs 29.34±1.79°C vs 28.06±1.34°C). The highest EBT was reported at 4.00 PM and the lowest at 8.00 AM. For the first time we found an influence of the circadian rhythm on EBT. These data support the validation of the EBT necessary for its promotion in clinical practice.

Viral colonization in exhaled breath condensate of lung cancer patients: Possible role of EBV and CMV

INTRODUCTION

Today, an increasing interest is being addressed to the viral etiology of lung tumors. As a consequence, research efforts are currently being directed to the identification of the new viruses involved in lung carcinogenesis toward which the screening programs could be directed.

OBJECTIVES

The aim of this study was to investigate the airways colonization by the Epstein-Barr virus (EBV) and Citomegalovirus (CMV) in patients affected by lung cancer using, as a respiratory non-invasive sample, the exhaled breath condensate (EBC).

METHODS

About 70 lung-cancer patients and 40 controls were enrolled. All subjects underwent bronchial brushing and EBC collection. EBV-DNA and CMV-DNA were evaluated in both samples by real-time PCR assay.

RESULTS

They were able to detect EBV and CMV in the EBC. An increase of the EBV positivity in non-small cell lung cancer (NSCLC) patients compared with controls and of the CMV in advanced stages of lung cancer were observed. The association of the positivity of the cytology and the CMV test (in EBC or brushing) slightly increased the sensitivity of malignant diagnosis.

CONCLUSION

EBV and CMV resulted detectable in the EBC. In consideration of the potential involvement of these viruses in lung cancer, which was confirmed in this study, future studies in this direction were supported.

Latex Allergy and Sensitization in Cities: A Survey in a Population at Risk

The constant increase in allergic diseases in western countries is correlated with changes in lifestyle and with the deterioration of the air inhaled by the inhabitants because of the growing concentrations of pollutant substances present. Within a population at risk, i.e., the inhabitants of cities, a group of subjects at even higher risk was selected, whose job exposes them to automobile exhaust fumes for many hours a day. All the study subjects underwent allergological screening and spirometry. The results obtained show an overall increase of respiratory allergic diseases but no increased sensitisation to latex. It therefore seems plausible that, besides social and lifestyle changes, the deterioration of the quality of the air could be considered responsible, at least in part, for the growing numbers of allergic subjects. This study offers an opportunity to reconsider the validity of the “hygiene hypothesis” as an explanation for the increase of allergic disease in western countries, although recent reports have indicated that a sedentary lifestyle may also contribute, together with environmental degradation, to the notably increased prevalence of allergic diseases in large cities in industrialized nations.

Analysis of mitochondrial DNA alteration in new phenotype ACOS

BACKGROUND

Mitochondria contain their own DNA (MtDNA) that is very sensitive to oxidative stress and as a consequence could be damaged in quantity. Oxidative stress is largely recognized to play a key role in the pathogenesis of asthma and COPD and might have a role in the new intermediate phenotype ACOS (asthma-COPD overlap syndrome). The aim of this study was to investigate MtDNA alterations, as an expression of mitochondrial dysfunction, in ACOS and to verify whether they might help in the identification of this new phenotype and in its differentiation from asthma and COPD.

METHODS

Ten (10) ACOS according to Spanish guidelines, 13 ACOS according to GINA guidelines, 13 COPD, 14 asthmatic patients and ten normal subjects were enrolled. They further underwent a blood, induced sputum and exhaled nitric oxide collection. Content of MtDNA and nuclear DNA (nDNA) were measured in the blood cells of patients by Real Time PCR.

RESULTS

ACOS patients showed an increase of MtDNA/nDNA ratio. Dividing ACOS according to guidelines, those from the Spanish showed a higher value of MtDNA/nDNA compared to those from GINA/GOLD (92.69 ± 7.31 vs 80.68 ± 4.16). Spanish ACOS presented MtDNA/nDNA ratio closer to COPD than asthma. MtDNA was higher in asthmatic, COPD, GINA and Spanish ACOS patients compared to healthy subjects (73.30 ± 4.47-137.0 ± 19.45-80.68 ± 4.16-92.69 ± 7.31 vs 65.97 ± 20.56).

CONCLUSION

We found an increase of MtDNA/nDNA ratio in ACOS subjects that led us to conclude that there is presence of mitochondrial dysfunction in this disease, that makes it closer to COPD than to asthma. Although the MtDNA/nDNA ratio results are a useful marker for differential diagnosis from asthma, COPD and ACOS, further studies are needed to confirm the potentiality of MtDNA/nDNA ratio and to a better characterization of ACOS.

HPV in exhaled breath condensate of lung cancer patients

Background:

A recent intriguing carcinogenetic hypothesis for lung cancer foresees its viral aetiology. The human papilloma virus (HPV) is the main virus actually recognised in the pathogenesis of lung cancer. The aim of this study was to investigate, for the first time to our knowledge, the presence of HPV in the exhaled breath condensate (EBC) of lung cancer patients.

Materials and method:

We enrolled 89 patients affected by lung cancer and 68 controls. HPV infections were investigated in their EBC, paired bronchial brushing and neoplastic lung tissue through genotyping.

Results:

We were able to detect HPV in the EBC, bronchial brushing and neoplastic lung tissue. We described the presence of an HPV infection in 16.4% of the subjects affected by non-small cell lung cancer, but in none of the controls. HPV 16 and 31 turned out to be the most widespread genotypes. The HPV positivity in airways as well as in the smoking habit was seen to independently increase the individual's susceptibility to developing lung cancer.

Conclusion:

When summing up, we demonstrated the possibility to identify an HPV infection in the EBC of lung cancer patients; further, we supported the notion that the EBC is a suitable tool to study airway colonisation. That being said, although further studies are needed to confirm our results, we retain the study of HPV in EBC to be very interesting in terms of future programmes involving lung-cancer screening.

Effect of CPAP-therapy on bronchial and nasal inflammation in patients affected by obstructive sleep apnea syndrome

BACKGROUND

Obstructive sleep apnea syndrome (OSAS) has been shown to be associated to upper and lower airways inflammation. Continuous positive airway pressure (CPAP) is the elective treatment of OSAS. The aim of the present study was to assess the effect of CPAP-therapy on airway and nasal inflammation.

METHODS

In 13 non-smoking subjects affected by untreated OSAS and in 11 non-smoking normal volunteers, airway inflammation was detected by analyses of the induced sputum. In the OSAS group measurements were repeated after 1, 10 and 60 days of the appropriate CPAP treatment. In addition, in 12 subjects of the OSAS group, nasal inflammation was detected by the analysis of induced nasal secretions at baseline, and after 1, 10 and 60 days of CPAP treatment.

RESULTS

OSAS patients, compared to normal controls, showed at baseline a higher percentage of neutrophils and a lower percentage of macrophages in the induced sputum. One, 10 and 60 days of appropriate CPAP-therapy did not change the cellular profile of the induced sputum. In addition, in the OSAS patients, the high neutrophilic nasal inflammation present under baseline conditions was not significantly modified by CPAP-therapy. Finally, no patients developed airway hyper-responsiveness after CPAP therapy.

CONCLUSIONS

In OSAS subjects, the appropriate CPAP-therapy, while correcting the oxygen desaturation, does not modify the bronchial and nasal inflammatory profile.

Exhaled NO and iNOS expression in sputum cells of healthy, obese and OSA subjects

BACKGROUND

Obstructive sleep apnoea (OSA) is associated with airways inflammation; a key role in this regard seems to be played by nitric oxide (NO). The aim of this study was to measure exhaled NO and expression of its enzyme, the inducible nitric oxide synthase (iNOS) in cells of induced sputum in OSA patients and in obese subjects without sleep apnoea and to correlate these inflammatory markers with severity of OSA.

METHODS

We enrolled 18 obese patients with OSA (10 men, age 48.2 +/- 8.4 years), 15 obese patients without OSA (eight men, age 52.8 +/- 11 years) and 10 healthy subjects (five men, age 42 +/- 4 years). Exhaled NO was measured using a chemiluminescence analyser; iNOS expression was measured in the sputum cells by immunocytochemistry.

RESULTS

Exhaled NO resulted significantly increased in OSA and in obese patients (23.1 +/- 2.1 and 17.9 +/- 2.1 p.p.b.) than in healthy subjects (7.2 +/- 0.6 p.p.b.; P < 0.001). OSA and obese patients showed a higher percentage of neutrophils and a lower percentage of macrophages in the induced sputum compared to healthy subjects. In addition, OSA and obese patients showed higher iNOS expression in neutrophils and in macrophages with respect to healthy subjects. A positive correlation between exhaled NO, iNOS expression and AHI was observed.

CONCLUSIONS

These data confirm the presence of airway inflammation in OSA and in obese patients, and suggest the possible role for NO and iNOS expression in neutrophils of the induced sputum as noninvasive markers to identify and monitor the airway inflammation in these subjects.

3p microsatellite signature in exhaled breath condensate and tumor tissue of patients with lung cancer

RATIONALE

Our group has recently demonstrated the possibility of studying microsatellite alterations (MAs) of 3p in the DNA of exhaled breath condensate (EBC) of patients with non-small cell lung cancer (NSCLC).

OBJECTIVES

To verify whether MAs analyzed in DNA from EBC reflect a profile of alterations present in tumor tissue of NSCLC.

METHODS

Fifty-nine subjects undergoing histologic diagnosis for clinical suspicion of lung cancer entered the study: 41 were found to have NSCLC and 18 to have nonneoplastic diseases. All subjects underwent allelotyping on DNA from whole blood, EBC, and lung tissue removed for histologic diagnosis by analyzing a panel of five microsatellites located in chromosomal region 3p. Results obtained from DNA of the three biological sites and nonneoplastic tissues from controls were compared.

MEASUREMENTS AND MAIN RESULTS

MAs in DNA from tumor tissues and EBC of each patient with cancer presented an overlapping profile of loss of heterozygosity and microsatellite instability. An MA profile of DNA of lung tissue reflecting the DNA of EBC profile from controls was also confirmed. Smoking status was associated with the presence of MAs in patients with NSCLC and in control subjects.

CONCLUSIONS

We demonstrated that MAs in DNA from EBC of patients with NSCLC are significantly more frequent than in control subjects. More interesting, the MA profile of DNA from EBC corresponds to that from lung cancer tissue of each patient with NSCLC.

Airway inflammation in subjects with gastro-oesophageal reflux and gastro-oesophageal reflux-related asthma

STUDY OBJECTIVES

Asthma and gastro-oesophageal reflux (GER) are both characterized by airway inflammation.

DESIGN

The purposes of this work were (i) to study airway inflammation in patients troubled by gastro-oesophageal reflux (GER) and GER associated with asthma, (ii) to ascertain whether GER can aggravate asthma by exacerbating the pre-existing airway inflammation and oxidative stress and (iii) to establish the validity of analysing breath condensate and induced sputum when studying the airways of subjects affected by GER. PATIENT S AND METHODS: We enrolled 14 patients affected by mild asthma associated with GER (40 +/-12 years), nine with mild but persistent asthma (39 +/- 13 years), eight with GER (35 +/- 11 years) and 17 healthy subjects (37 +/- 9 years). Sputum cell counts and concentrations of interleukin-4 (IL-4), IL-6 and 8-isoprostane were measured in breath condensate and supernatant.

MEASUREMENTS AND RESULTS

GER-related asthma is characterized by an eosinophilic inflammation, as determined by elevated concentrations of IL-4 in breath condensate and sputum supernatant, and by sputum cell analysis. GER alone presents a neutrophilic pattern of inflammation when determined by elevated concentrations of IL-6 in sputum cell analysis. A concomitant increase has been found in 8-isoprostane in GER associated (or not associated) with asthma.

CONCLUSIONS

We conclude that GER is characterized by a neutrophilic airway inflammation and by increased oxidative stress. GER does not however aggravate pre-existing airway inflammation in asthma patients. Determinations of inflammatory and oxidant markers in the breath condensate of subjects with GER reflect these measured in the induced sputum.

3p microsatellite alterations in exhaled breath condensate from patients with non-small cell lung cancer

The still-high mortality for lung cancer urgently requires the availability of new, noninvasive diagnostic tools for use in early diagnosis and screening programs. Recently, exhaled breath condensate (EBC) has been proposed as a useful tool to obtain biological information on lung cancer disease. This study provides, for the first time, evidence that DNA alterations already described in lung cancer are detectable in EBC from patients with non-small cell lung cancer (NSCLC) and in healthy subjects. Thirty patients with histologic evidence of NSCLC and 20 healthy subjects were enrolled in the present study. All subjects had allelotyping analysis of DNA from EBC (EBC-DNA) and from whole blood (WB-DNA) of a selected panel of five microsatellites (D3S2338, D3S1266, D3S1300, D3S1304, D3S1289) located in chromosomal region 3p. Results from healthy subjects and subjects with cancer, and from EBC and WB, were compared. In addition, the relationships with smoking habit and clinicopathologic tumor features were considered. Microsatellite alterations (MAs) were found in 53% of EBC-DNA and in 10% of WB-DNA loci investigated in patients with NSCLC (p < 10(-6)); conversely, MAs were present only in 13% of EBC-DNA and in 2% of WB-DNA informative loci in healthy subjects. In patients with NSCLC, a direct association between number of MAs detected in EBC-DNA and tobacco consumption was observed. We conclude that EBC-DNA is highly sensitive in detecting MA information unique to patients with lung cancer. Furthermore, MA information seems to be directly related with tobacco consumption, and is potentially applicable to screening and early diagnostic programs for patients with NSCLC.

The mechanics of the lung parenchyma and airway responsiveness to metacholine

The lung parenchyma is anatomically and mechanically connected to the intraparenchymal airways. Due to forces of interdependence the lung parenchyma represents a mechanical load that opposes bronchial narrowing during airway smooth muscle activation. The mechanical load caused by the parenchyma is a function of the number of the alveolar attachments to the airways, and of the mechanical properties of the parenchyma. The extracellular matrix is a major component of the lung parenchyma responsible of most of its mechanical properties. The excessive airway narrowing observed in the asthmatic population may be the consequence of the altered mechanical properties of the extracellular matrix reducing the mechanical load that opposes airway smooth muscle contraction.

Supplementary oxygen in healthy subjects and those with COPD increases oxidative stress and airway inflammation

BACKGROUND

Hyperoxia increases oxidative stress through the generation of reactive oxygen species and may therefore enhance inflammation in the lungs. The aim of this study was to investigate whether short term supplementary oxygen (28%) increases oxidative stress and inflammation in the airways by measuring 8-isoprostane and interleukin 6 (IL-6) concentrations in exhaled breath condensate.

METHODS

Twenty three healthy subjects (12 men, mean (SD) age 48 (7) years) and 23 patients with chronic obstructive pulmonary disease (COPD; 15 men, mean (SD) age 56 (5) years) were studied. 8-isoprostane and IL-6 concentrations were measured by immunoassay.

RESULTS

Increased concentrations of 8-isoprostane and IL-6 were found in all subjects after breathing 28% oxygen for 1 hour. In healthy subjects the concentrations of 8-isoprostane and IL-6 were 10.9 (2.9) pg/ml and 4.9 (0.8) pg/ml, respectively, compared with baseline concentrations of 6.1 (1.3) pg/ml and 2.9 (0.6) pg/ml, and in patients with COPD the concentrations were 27.9 (3.1) pg/ml and 8.3 (1.2) pg/ml), respectively, compared with baseline concentrations of 18.9 (3.6) pg/ml and 6.3 (0.6) pg/ml. By contrast, breathing air through the same face mask for 1 hour had no significant effects on 8-isoprostane or IL-6 concentrations in normal subjects or those with COPD.

CONCLUSIONS

These findings suggest that short term supplementary oxygen may enhance oxidative stress and inflammation in the airways. Whether this happens with long term oxygen therapy needs to be determined.

Endothelin-1 is increased in the breath condensate of patients with non-small-cell lung cancer

One recent line of cancer research is currently directed to the study of growth factors. Of increasing interest is endothelin-1 (ET-1), a mitogenic factor already investigated in several human cancer cell lines, which has been found to participate in the development and progression of tumours. This peptide has an important role also in non-small-cell lung cancer (NSCLC) where ET-1 expression has been found in 100% of cell lines.

OBJECTIVES

The aim of this study was to measure ET-1 concentrations in the airways of patients with NSCLC using a completely non-invasive procedure--the breath condensate--and to verify the involvement of this peptide in the growth of lung tumours.

METHODS

We enrolled 30 patients (17 men, median age 63 years; range 53-74) with histological evidence of NSCLC and 15 healthy controls (9 men, median age 59 years; range 52-70). ET-1 was measured in the exhaled breath condensate by means of a specific enzyme immunoassay kit.

RESULTS

Higher concentrations of exhaled ET-1 were found in NSCLC patients (8.3 +/- 0.7 pg/ml) compared to controls (5.2 +/- 0.5 pg/ml, p < 0.0001). A statistically significant difference was observed between patients with distant metastases (stage IV) of NSCLC (8.9 +/- 0.6 pg/ml) and those with locoregional disease (stage I-III) (7.9 +/- 0.5 pg/ml). A significant reduction in ET-1 levels was found in 14 patients after surgical removal of the tumour either associated with or without adjuvant chemotherapy (6.3 +/- 0.5 vs. 7.9 +/- 0.4 pg/ml, p < 0.0001).

CONCLUSIONS

These findings suggest that the measurement of ET-1 in the breath condensate of patients with NSCLC could be proposed as a marker for early detection of NSCLC as well as for monitoring reduction or progression of the neoplasm in the follow-up of treated patients.

Increased inflammatory markers in the exhaled breath condensate of cigarette smokers

Cigarette smoking induces an inflammatory response in the airways that may play a key role in the pathogenesis of chronic obstructive pulmonary disease. Noninvasive markers of inflammation may, therefore, be useful in monitoring the airways of smokers as well as in the screening of subjects at high risk of developing airway obstruction. The aim of the present study was to determine whether the concentrations of the pro-inflammatory cytokine, interleukin (IL)-6, is increased in the exhaled breath condensate of smokers and whether the number of cigarettes smoked has any influence on the exhaled concentrations. The possibility that exhaled IL-6 levels are related to exhaled carbon monoxide (CO) and lung function has also been explored. Another inflammatory marker, leukotriene (LT), was also measured. Twenty-one smokers (39+/-7 yrs, 13 male) and 14 nonsmokers (45+/-6 yrs, eight male) were recruited. IL-6 and LTB4 levels in the breath condensate were measured with an immunoassay kit and exhaled CO examined by means of a modified electrochemical sensor. Higher IL-6 and exhaled CO concentrations were found in current smokers (5.6+/-1.4 pg x mL(-1) and 16.7+/-5.5 parts per million (ppm)) than in nonsmokers (2.6+/-0.2 pg x mL(-1) and 2.1+/-0.6 ppm). Elevated concentrations of LTB4 were also observed in smokers compared to nonsmokers (9.4+/-0.4 pg x mL(-1) versus 6.1+/-0.3 pg x mL(-1)). In addition, there was a correlation between IL-6 concentrations, the number of cigarettes smoked per day, exhaled CO, LTB4 and lung function. Exhaled interleukin-6 and leukotriene B4 levels may be useful noninvasive markers of airway inflammation in cigarette smokers.

Sleep-related breathing disorders, loud snoring and excessive daytime sleepiness in obese subjects

OBJECTIVE

To investigate the prevalence of sleep breathing disorders, loud snoring and excessive daytime sleepiness in a group of obese subjects, and to identify the predictors of obstructive sleep apnea (OSA) severity in these patients.

SUBJECTS

A total of 161 consecutive obese patients (body mass index (BMI)> or =30.0 kg/m(2)), ranging between 30.0 and 67.3, represented by 57 men and 104 women, aged 16-75 y. Forty (15 men and 25 women) age-matched (20-70 y) nonobese (BMI<27 kg/m(2)) volunteers were also recruited for the study.

MEASUREMENTS

Respiratory function parameters, nocturnal sleep quality (evaluated by a specific questionnaire), nocturnal hypoventilation and OSA (evaluated by night polysomnography) were examined in all subjects. Anthropometric parameters (neck circumference, waist circumference, waist-to-hip ratio) were also investigated.

RESULTS

Eighty-three obese patients (51.5% of the obese group) had a respiratory disturbance index (RDI)> or =10, corresponding to a moderate or severe sleep apnea. In particular, 24.8% (40/161), ie a quarter of all obese patients, were affected by severe OSA and this alteration was present in 42.1% of obese men (24/57) and in 15.4% (16/104) of obese women. When a stepwise multiple regression analysis was performed, neck circumference in men and BMI in women were shown to be the strongest predictors of sleep apnea. Twenty-nine percent of all obese subjects (40.3% of men and 23.1% of women) showed nocturnal hypoventilation; however, it was present as a unique breathing alteration in only 5% of the obese population. The percentage of patients having excessive daytime sleepiness was significantly higher than in nonobese subjects, even when only nonapneic obese patients were considered (P<0.001).

CONCLUSION

This study shows that OSA is present in more than 50% of a population of obese patients with a mean BMI higher than 40.0, this percentage being much higher than that commonly reported in previous studies, particularly in women. Neck circumference in men and BMI in women seem to be the strongest predictors of the severity of OSA in obese patients. Nocturnal hypoventilation seems to be present in more than 29% of a severe obese population. Moreover, this study indicates that morbid obesity can be associated with excessive daytime sleepiness even in the absence of sleep apnea.

Prevalence and mechanisms of diurnal hypercapnia in a sample of morbidly obese subjects with obstructive sleep apnoea

It is well known that obstructive sleep apnoea is especially frequent in the morbidly obese. In these subjects diurnal chronic hypercapnia, whose mechanism is still debated, may be present. Our study was performed to evaluate the prevalence and the mechanism of diurnal hypercapnia in the morbidly obese affected by obstructive sleep apnoea. From a population referred to our centre because of suspicion of sleep related breathing disorders, we selected 285 subjects without cardiopulmonary, neuromuscular or endocrinological diseases: 89 (36 M and 53 F, aged 46+/-13 years) had body mass index (BMI) > or = 40 kg m(-2) (MO group: morbidly obese subjects) and 196 (99 M and 97 F, aged 48+/-16 years) had BMI <40 kg m(-2) (NMO group: non-morbidly obese subjects). Then the MO group was divided into three subgroups: normocapnic subjects without obstructive sleep apnoea, normocapnic subjects with obstructive sleep apnoea, hypercapnic subjects with obstructive sleep apnoea; while we found no hypercapnic subject without obstructive sleep apnoea. All subjects underwent anthropometric evaluations and bioelectrical impedance analyses, respiratory function tests and arterial blood gas analysis, a modified version of the Sleep and Healthy questionnaire and a full night polysomnography. Our results showed that hypercapnia (PaCO2 > or = 45 mm Hg) associated with obstructive sleep apnoea [respiratory disturbance index (RDI) > or = 10 h(-1)] was found in 27% of the morbidly obese subjects, but only in 11% of the nonmorbidly obese ones (P<0.01). The comparison among the three subgroups, in which we divided the morbidly obese subjects, shows that those with hypercapnia and obstructive sleep apnoea had significantly more important ventilatory restrictive defects [forced vital capacity (FVC)% of pred 73.27+/-14 81 vs. 82.37+/-16.93 vs. 87.25+/-18.14 respectively; total lung capacity (TLC)% of pred 63.83+/-16.35 vs. 79.11+/-14.15 vs. 87.01+/-10.5], a significantly higher respiratory disturbance index (RDI 46.34+/-26.90 vs. 31.79+/-22.47 vs. 4.98+/-3.29) a longer total sleep time with oxyhaemoglobin saturation<90% [total sleeptime (TST)SaO2<90% 63.40+/-33.86 vs. 25.95+/-29.34 vs. 8.22+/-22.12] and a lower rapid eye movement (REM) stage (9.5+/-1.2 vs. 14.0+/-0.9 vs. 17.05+/-1.2) than normocapnic subjects with obstructive sleep apnoea or subjects without obstructive sleep apnoea. The best model to predict PaCO2 resulted from a combination of TSTSaO2<90% (r2 = 0.22, P<0.001), forced expiratory volume in 1 sec (FEV1)% of pred (r2 = 0.09, P<0.01), FVC % of pred (r2 = 0.075, P<0.01). In conclusion our study suggests that diurnal hypercapnia is frequently associated with obstructive sleep apnoea in the morbidly obese without chronic obstructive pulmonary disorder (COPD) and that ventilatory restriction and sleep related respiratory disturbances correlate to diurnal hypercapnia.

Nocturnal oxygen desaturation in patients with congestive heart failure

The aim of our study was to evaluate the modifications of the respiratory pattern during sleeping in patients with congestive heart failure (CHF) by a simple pulse-oxymetry. We studied 10 subjects (8M/2F), mean age 71.4 +/- 12.4 yrs, admitted to sub-intensive cardiological therapy unit, with diagnosis of CHF due to left ventricular insufficiency by ischemic, hypertensive or idiopathic cardiopathy, when in a stable clinical condition. All patients presented arterial blood gas values within normal limits. The ejection fraction of left ventricle showed a mean value of 30.4 +/- 8.2% (range 20%-45%). Nocturnal pulse-oxymetry was performed by pulse-oxymeter (PULSOX 7 Minolta) provided with a digital probe at a sliding speed 24 cm/h. Our data showed that all patients presented nocturnal desaturation episodes (mean oxygen desaturation index 15.7 +/- 18.4). In two patients, we found an "Overlap Syndrome" (obstructive sleep apnoea in presence of cardiopathy). In other patients pulse-oxymetry showed a typical sequence of "fall-rise" basal O2 saturation lasting from 36 to 72 seconds, collected in "wave trains" which were present from 14% to 70% of total sleep time compatible with periodic breathing. In conclusion, our study shows that patients affected by CHF, even if in stable condition and with a PaO2, within normal values, present more or less severe disturbances of nocturnal SaO2, with periodic and regular sequences of SaO2 fall-rise that may be referred to ventilatory troubles such as periodic breathing or Cheyne-Stokes breathing. In these patients the pulse-oxymetry may be considered an efficacious, simple, cheap and well tolerated method.

Sleep related O2 desaturation in COPD patients with normoxaemia and mild hypoxyaemia

It is unknown whether daytime features predict oxygenation during sleep in COPD patients with normoxaemia or mild hypoxaemia. In this study our purpose was to evaluate by a pulse oxymeter, nocturnal desaturation in 33 COPD with PaO2 > 60 mmHg and to examine some daytime parameters as possible predictors of nocturnal hypoxaemia. A significant nocturnal desaturation has been defined by spending > or = 30% of total sleep-time with a TSTSaO2 < 90% > 30. According to this criterion we classified our patients in Desaturators (D) and Non Desaturators (ND). Our results showed that 39% of our patients were D and 61% ND. Among anthropometric and respiratory functional data we found that daytime SaO2B (r = 0.74 p < 0.001) daytime PaO2 (r = 0.47 p < 0.01) and daytime PaCO2 (r = 0.45 p < 0.05) were significantly correlated with the nocturnal oxygen desaturation and can predict the presence of sleep related hypoxaemia. In conclusion, our study confirms that a relatively high percentage of COPD patients with normoxaemia or borderline hypoxaemia exhibits significant nocturnal hypoxaemia. Further studies will suggest whether sleep related hypoxaemia deserves nocturnal oxygen therapy.

Asthma relieved by acetylsalicylic acid and nonsteroid anti-inflammatory drugs

The authors report 2 typical asthmatic cases in whom the administration of acetylsalicylic acid (ASA) and nonsteroid anti-inflammatory drugs (NSAID) resulted in bronchodilatation. 500 mg of ASA were administered intravenously to 1 patient and the other was treated with ASA, indomethacin, noramidopyrine intravenously and acetaminophen orally during a bronchospastic attack. FEV1 and SRAW were measured before and after drug administration. The test was repeated with placebo (physiological saline). FEV1 increased rapidly after ASA and NSAID administration. Although the pathogenesis of asthma reversed by aspirin is not entirely clear, the authors suggest an alteration of sensitivity of the cyclo-oxygenase enzyme due to the inhibitory action of ASA and NSAID.

Functional assessment of airways bronchoconstriction with nebulized acetyl salicylic acid

The aim of our study was to verify the functional modifications affecting central and peripheral airways during bronchoconstriction induced by aerosolized aspirin, so as to better understand the pathophysiologic mechanisms of the asthmatic crises in A.S.A. sensitive patients. The preliminary results were presented of a study carried out o 12 asthmatic A.S.A. sensitive patients, 7 of whom were females and 5 males, between the ages of 22 and 57 years. A.S.A. sensitivity was found in their medical history, in some cases, it had been confirmed by oral A.S.A. challenge. Among these patients, 6 were also affected by nasal polyposis. The method used was recently described by Bianco et al. although slightly modified by us: a fresh aqueous solution (18%) of A.S.A. -L is diluted 1:3 in saline; 4 ml of this solution is transferred to a glass nebulizer activated by a small compressor. The patients underwent treatment for 60 sec, during which a dose of approximately 1,8 mg of A.S.A. was inhaled, corresponding to about 40 mg of aspirin taken orally. In comparison with the reactions induced by oral challenge, those obtained with this treatment are easier, faster and confined only to the respiratory system. Before giving A.S.A. to the patients, control tests using saline aerosol were done. The functional assessment was performed under basal conditions, and 1, 15, 30, 60, 90 and 120 minutes following administration of A.S.A. since bronchoconstriction caused by nebulized A.S.A. usually reaches peak values between the 60th and 90th min. after which it gradually decreases over the following two hours. Our results show that, though A.S.A. induced bronchoconstriction prevails at large airways, it also influences the distal tracts of the tracheobronchial tree, since both SRAW, FEV1 and Vmax50C are modified at the same time.