Nintedanib in patients with progressive fibrosing interstitial lung diseases-subgroup analyses by interstitial lung disease diagnosis in the INBUILD trial: a randomised, double-blind, placebo-controlled, parallel-group trial

BACKGROUND

The INBUILD trial investigated the efficacy and safety of nintedanib versus placebo in patients with progressive fibrosing interstitial lung diseases (ILDs) other than idiopathic pulmonary fibrosis (IPF). We aimed to establish the effects of nintedanib in subgroups based on ILD diagnosis.

METHODS

The INBUILD trial was a randomised, double-blind, placebo-controlled, parallel group trial done at 153 sites in 15 countries. Participants had an investigator-diagnosed fibrosing ILD other than IPF, with chest imaging features of fibrosis of more than 10% extent on high resolution CT (HRCT), forced vital capacity (FVC) of 45% or more predicted, and diffusing capacity of the lung for carbon monoxide (DLco) of at least 30% and less than 80% predicted. Participants fulfilled protocol-defined criteria for ILD progression in the 24 months before screening, despite management considered appropriate in clinical practice for the individual ILD. Participants were randomly assigned 1:1 by means of a pseudo-random number generator to receive nintedanib 150 mg twice daily or placebo for at least 52 weeks. Participants, investigators, and other personnel involved in the trial and analysis were masked to treatment assignment until after database lock. In this subgroup analysis, we assessed the rate of decline in FVC (mL/year) over 52 weeks in patients who received at least one dose of nintedanib or placebo in five prespecified subgroups based on the ILD diagnoses documented by the investigators: hypersensitivity pneumonitis, autoimmune ILDs, idiopathic non-specific interstitial pneumonia, unclassifiable idiopathic interstitial pneumonia, and other ILDs. The trial has been completed and is registered with ClinicalTrials.gov, number NCT02999178.

FINDINGS

Participants were recruited between Feb 23, 2017, and April 27, 2018. Of 663 participants who received at least one dose of nintedanib or placebo, 173 (26%) had chronic hypersensitivity pneumonitis, 170 (26%) an autoimmune ILD, 125 (19%) idiopathic non-specific interstitial pneumonia, 114 (17%) unclassifiable idiopathic interstitial pneumonia, and 81 (12%) other ILDs. The effect of nintedanib versus placebo on reducing the rate of FVC decline (mL/year) was consistent across the five subgroups by ILD diagnosis in the overall population (hypersensitivity pneumonitis 73·1 [95% CI -8·6 to 154·8]; autoimmune ILDs 104·0 [21·1 to 186·9]; idiopathic non-specific interstitial pneumonia 141·6 [46·0 to 237·2]; unclassifiable idiopathic interstitial pneumonia 68·3 [-31·4 to 168·1]; and other ILDs 197·1 [77·6 to 316·7]; p=0·41 for treatment by subgroup by time interaction). Adverse events reported in the subgroups were consistent with those reported in the overall population.

INTERPRETATION

The INBUILD trial was not designed or powered to provide evidence for a benefit of nintedanib in specific diagnostic subgroups. However, its results suggest that nintedanib reduces the rate of ILD progression, as measured by FVC decline, in patients who have a chronic fibrosing ILD and progressive phenotype, irrespective of the underlying ILD diagnosis.

FUNDING

Boehringer Ingelheim.

Variability and effects of bronchial colonisation in patients with moderate COPD

Sputum and lung function were periodically assessed in stable moderate chronic obstructive pulmonary disease (COPD) outpatients to determine relationships between bronchial colonisation and inflammation. Relationships between potentially pathogenic microorganism (PPM) typology, bronchial inflammation (neutrophilia, tumour necrosis factor-alpha, interleukin (IL)-1beta, IL-6, IL-8, IL-10 and IL-12) and post-bronchodilator decline in forced expiratory volume in 1 s (FEV(1)) were analysed. PPMs periodically showing the same molecular profile using pulse field gel electrophoresis were considered long-term persistent. Bronchial colonisation was observed in 56 out of 79 follow-up examinations (70.9%) and was mainly due to Haemophilus influenzae, Pseudomonas aeruginosa and enterobacteria (n = 47). These PPMs were all related to sputum neutrophilia (p< or =0.05, Chi-squared test), and H. influenzae was related to higher levels of IL-1beta (p = 0.005) and IL-12 (p = 0.01), with a dose-response relationship (Spearman's correlation coefficient of 0.38 for IL-1beta (p = 0.001), and of 0.32 for IL-12 (p = 0.006)). Haemophilus parainfluenzae was not associated with an identifiable inflammatory response. Long-term persistence of the same strain was observed in 12 examinations (21.4%), mainly due to P. aeruginosa or enterobacteria. A neutrophilic bronchial inflammatory response was associated with a statistically significant decline in FEV(1) during follow-up (OR 2.67, 95% CI 1.07-6.62). A load-related relationship to bronchial inflammation in moderate COPD was observed for colonisation by H. influenzae, but not for colonisation by H. parainfluenzae.

Lipopolysaccharide-binding protein and CD14 are increased in the bronchoalveolar lavage fluid of smokers

Lipopolysaccharide-binding protein (LBP) and CD14 contribute to the recognition of pathogens by cells, which triggers the activation of defence responses. Smoking is a risk factor for the development of chronic obstructive pulmonary disease (COPD) and respiratory infections. The current authors theorised that levels of LBP and CD14 in the lungs of smokers would be higher than those in the lungs of never-smokers. These elevated levels could affect host responses upon infection. LBP, soluble CD14 (sCD14) and interleukin (IL)-8 were detected by ELISA. Nuclear factor (NF)-kappaB, p38 and the inhibitor IkappaBalpha were studied by immunoassays. Gene expression was assessed by RT-PCR. Bronchoalveolar lavage levels of LBP and CD14 were significantly higher in smokers and COPD patients than in never-smokers, whereas levels of both proteins were not significantly different between smokers and COPD patients. IL-6, IL-1beta and cigarette smoke condensate induced the expression of LBP and CD14 by airway epithelial cells. LBP and sCD14 inhibited the nontypeable Haemophilus influenzae (NTHi)-dependent secretion of IL-8 and the activation of NF-kappaB and p38 mitogen-activated protein kinase signalling pathways but they increased the internalisation of NTHi by airway epithelial cells. Thus, in the inflamed airways of smokers both proteins could contribute to inhibit bacteria-dependent cellular activation without compromising the internalisation of pathogens by airway cells.

Phenotypic characterisation of T-lymphocytes in COPD: abnormal CD4+CD25+ regulatory T-lymphocyte response to tobacco smoking

Tobacco smoking induces an inflammatory response in the lungs of all smokers but, for reasons that are still poorly understood, only a proportion of them develop chronic obstructive pulmonary disease (COPD). Recent evidence indicates that this inflammatory response persists after smoking cessation, suggesting some type of auto-perpetuation mechanism similar to that described in autoimmune disorders. T-lymphocytes (CD4+ and CD8+) have been implicated in the pathogenesis of both COPD and several autoimmune processes. A subtype of regulatory CD4+ T-cells expressing CD25 (Tregs) plays a critical role in the maintenance of peripheral tolerance and the prevention of autoimmunity, but their potential role in COPD has not been explored. The present study sought to evaluate maturation (CD45RA/CD45R0) and activation markers (CD28) of T-lymphocytes and to explore potential Treg abnormalities in COPD. Flow cytometry was used to characterise T-lymphocytes obtained from blood and bronchoalveolar lavage fluid (BALF) in 23 patients with moderate COPD, 29 smokers with normal lung function and seven never-smokers. The main findings were that in BALF: patients with COPD showed higher CD8+CD45RA+ and lower CD8+CD45R0+ than smokers with normal lung function; and compared with never-smokers, smokers with preserved lung function showed a prominent upregulation of Tregs that was absent in patients with COPD. These observations indicate a final maturation-activation state of CD8+ T-lymphocytes in chronic obstructive pulmonary disease and, for the first time, identify a blunted regulatory T-cell response to tobacco smoking in these patients, further supporting a potential involvement of the acquired immune response in the pathogenesis of the disease.

Intracellular cytokine profile of T lymphocytes in patients with chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is characterized by an excessive inflammatory response to inhaled particles, mainly tobacco smoking. T lymphocytes are important regulatory cells that secrete several cytokines and participate actively in this inflammatory response. According to the pattern of cytokines secreted, the immune response is classified as cytotoxic or type 1 [interferon (IFN)-gamma-, interleukin (IL)-2-dependent] and humoral or type 2 (IL-4-, IL-5-, IL-10- and IL-13-dependent). This paper sought to compare the intracellular profile of cytokine expression determined by flow cytometry in T lymphocytes harvested from bronchoalveolar lavage (BAL) and peripheral blood in patients with COPD, smokers with normal lung function and never smokers. We found that BAL T lymphocytes from COPD patients had a higher percentage of positive stained cells for most of the cytokines analysed when compared to never smokers or smokers with normal lung function. Differences reached statistical significance for IL-4, IL-10 and IL-13, particularly in CD8(+) T cells. Furthermore, the expression of most of these cytokines was related inversely to the degree of airflow obstruction present suggesting local activation and/or selective homing of T lymphocytes to the lungs in COPD patients. These observations were not reproduced in circulating T lymphocytes. These results suggest that BAL T lymphocytes in patients with COPD produce more cytokines than in controls and tend to show a type 2 pattern of intracellular cytokine expression, particularly a Tc-2 profile. This is related inversely to the degree of airflow obstruction present.

Telomere shortening in smokers with and without COPD

Telomeres are complex DNA-protein structures located at the end of eukaryotic chromosomes. Telomere length shortens with age in all replicating somatic cells. It has been shown that tobacco smoking enhances telomere shortening in circulating lymphocytes. The present study investigated whether this effect was further amplified in smokers who develop chronic obstructive pulmonary disease. Telomere length was determined by fluorescence in situ hybridisation in circulating lymphocytes harvested from 26 never-smokers, 24 smokers with normal lung function and 26 smokers with moderate-to-severe airflow obstruction (forced expiratory flow in one second 48+/-4% predicted). In contrast to never-smokers, telomere length significantly decreased with age in smokers. There was also a dose-effect relationship between the cumulative long-life exposure to tobacco smoking (pack-yrs) and telomere length. The presence and/or severity of chronic airflow obstruction did not modify this relationship. The results of the current study confirm that smoking exposure enhances telomere shortening in circulating lymphocytes. It also demonstrates a dose-effect relationship between exposure to tobacco smoking and telomere length, but failed to show that this effect is amplified in smokers who develop chronic obstructive pulmonary disease.

Decreased macrophage release of TGF-beta and TIMP-1 in chronic obstructive pulmonary disease

The present study tested the hypothesis that alveolar macrophages (AM) from patients with chronic obstructive pulmonary disease (COPD) release more pro-inflammatory and/or less anti-inflammatory mediators than those from smokers with normal lung function and never-smokers. AM were sorted by flow cytometry from bronchoalveolar lavage fluid in 13 patients with COPD (mean+/-SEM 67+/-2 yrs, forced expiratory volume in one second (FEV1) 61+/-4% reference), 16 smokers with normal lung function (55+/-2 yrs, FEV1 97+/-4% reference) and seven never-smokers (67+/-7 yrs, FEV1 94+/-4% reference). After sorting, AM were cultured (with and without lipopolysaccharide stimulation) after 4 h and 24 h, and the concentrations of leukotriene B4 (LTB4), transforming growth factor (TGF)-beta1 and tissue inhibitor of metalloproteinase (TIMP)-1 were quantified in the supernatant by ELISA. The production of reactive oxygen intermediates (ROI) in freshly isolated AM was determined by flow cytometry. LTB4 secretion and ROI production were not different between groups. In contrast, AM from COPD patients released significantly less TGF-beta1 and TIMP-1 than those from smokers with normal lung function and nonsmokers. In conclusion, these observations are compatible with reduced anti-inflammatory and anti-elastolytic capacity in chronic obstructive pulmonary disease, which is likely to contribute to the pathogenesis of the disease.

Blunted gamma delta T-lymphocyte response in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is characterised by an excessive inflammatory response to inhaled particles, mostly tobacco smoking. Although inflammation is present in all smokers, only a percentage of them develop COPD. T-lymphocytes are important effector and regulatory cells that participate actively in the inflammatory response of COPD. They comprise the T-cell receptor (TCR)-alpha beta (CD4+ and CD8+) and TCR-gamma delta T-lymphocytes. The latter represent a small percentage of the total T-cell population, but play a key role in tissue repair and mucosal homeostasis. To investigate TCR-alpha beta (CD4+ and CD8+) and TCR-gamma delta T-lymphocytes in COPD, the present authors determined, by flow cytometry, the distribution of both subpopulations in peripheral blood and bronchoalveolar lavage (BAL) samples obtained from patients with COPD, smokers with normal lung function and never-smokers. The present study found that: 1) the distribution of CD4+ and CD8+ lymphocytes in blood and BAL was similar in all three groups; 2) compared with nonsmokers, gamma delta T-lymphocytes were significantly increased in smokers with preserved lung function; and 3) this response was blunted in patients with COPD. These results highlight a novel, potentially relevant, pathogenic mechanism in chronic obstructive pulmonary disease.

Oxidative stress and airway inflammation in severe exacerbations of COPD

BACKGROUND

A study was undertaken to assess both oxidative stress and inflammation in the lungs of patients with chronic obstructive pulmonary disease (COPD) during severe and very severe exacerbations compared with those with stable COPD, healthy smokers, and non-smokers. Two sites within the lungs were compared: the large airways (in sputum) and the peripheral airways (by bronchoalveolar lavage (BAL)).

METHODS

BAL fluid cell numbers and levels of tumour necrosis factor (TNFalpha) and interleukin (IL)-8 were measured as markers of airway inflammation and glutathione (GSH) levels as a marker of antioxidant status. Nuclear translocation of the pro-inflammatory transcription factors nuclear factor-kappaB (NF-kappaB) and activator protein 1 (AP-1) were also measured by electromobility shift assay in BAL fluid leucocytes and lung biopsy samples.

RESULTS

Influx of inflammatory cells into the peripheral airways during exacerbations of COPD was confirmed. Increased IL-8 levels were detected in BAL fluid from patients with stable COPD compared with non-smokers and healthy smokers, with no further increase during exacerbations. In contrast, IL-8 levels in the large airways increased during exacerbations. GSH levels were increased in the BAL fluid of smokers (444%) and patients with stable COPD (235%) compared with non-smokers and were reduced during exacerbations (severe 89.2%; very severe 52.3% compared with stable COPD). NF-kappaB DNA binding in BAL leucocytes was decreased in healthy smokers compared with non-smokers (41.3%, n = 9, p<0.001) but did not differ in COPD patients, whereas AP-1 DNA binding was significantly decreased during exacerbations of COPD.

CONCLUSION

There is evidence of increased oxidative stress in the airways of patients with COPD that is increased further in severe and very severe exacerbations of the disease. This is associated with increased neutrophil influx and IL-8 levels during exacerbations.

Phenotypic characterisation of alveolar macrophages and peripheral blood monocytes in COPD

Alveolar macrophages (AM) participate actively in the inflammatory response that characterises chronic obstructive pulmonary disease (COPD). The present study investigated potential changes in AM phenotypes in patients with COPD. Using flow cytometry, the surface expression of receptors implicated in phagocytosis (CD44, CD36, CD51, CD61, CD14), antigen-presenting capacity (human leukocyte antigen (HLA)-DR), costimulatory molecules (CD80, CD86, CD40) and complement receptor type 3 were assessed in AM from 18 patients with COPD, 14 smokers with normal lung function and nine nonsmokers. When compared to smokers with normal lung function and nonsmokers, the surface expression of HLA-DR and CD80 was lower in AM of patients with COPD. In addition, these patients had a higher percentage of AM with a low level surface expression of CD44. There did not appear to be any difference in the other receptors studied in AM between the three groups. The expression of all these receptors in peripheral blood monocytes also did not differ between groups. In conclusion, these observations suggest that the cell-mediated immune function of alveolar macrophages can be reduced in chronic obstructive pulmonary disease, and that this is a local rather than a systemic event.

NF-kappaB activation and iNOS upregulation in skeletal muscle of patients with COPD and low body weight

BACKGROUND

Weight loss, mostly due to skeletal muscle atrophy, is a frequent and clinically relevant problem in patients with chronic obstructive pulmonary disease (COPD). The molecular mechanisms underlying this phenomenon are unclear. This study sought to investigate whether activation of the nuclear transcription factor NF-kappaB and upregulation of the inducible form of nitric oxide synthase (iNOS) occur in the skeletal muscle of patients with COPD and low body weight as potential molecular mechanisms leading to cachexia

METHODS

NF-kappaB DNA binding activity was determined by electromobility shift assay and the immunoreactivity of its inhibitory subunit IkappaB-kappa and that of iNOS by Western blot analysis in biopsy specimens of the quadriceps femoris muscle of seven COPD patients with normal body mass index (BMI, 27.5 (1) kg/m(2)) and seven patients with low BMI (18.5 (1) kg/m(2)).

RESULTS

Compared with patients with normal body weight, those with low BMI showed a 30% increase in NF-kappaB DNA binding activity, a lower expression of IkappaB-alpha (3.37 (0.47) IOD v 5.96 (0.75) IOD, p<0.05; mean difference 2.59; 95% CI -4.53 to -0.65) and higher iNOS expression (1.51 (0.29) IOD v 0.78 (0.11) IOD, p<0.05; mean difference 0.74; 95% CI 0.04 to 1.42).

CONCLUSIONS

NF-kappaB activation and iNOS induction occur in skeletal muscle of COPD patients with low body weight. These changes might contribute to the molecular pathogenesis of cachexia in COPD.

Effects of obesity upon genioglossus structure and function in obstructive sleep apnoea

Obesity is a common feature of the obstructive sleep apnoea syndrome. It can influence the structure and function of skeletal muscles. However, its effects upon the upper airway muscles have not been explored directly. This study assessed the structure and function of the genioglossus in patients with obstructive sleep apnoea syndrome and in healthy subjects (with and without obesity, defined by a body mass index > 30 kg x m(-2)). Further, to investigate the effects of continuous positive airway pressure (CPAP) treatment, patients with obstructive sleep apnoea syndrome after at least 1 yr under CPAP were also studied. The study found that obese and nonobese patients showed different in vitro geniglossus endurance properties. In obese patients, geniglossus endurance was indistinguishable from normal while, nonobese patients, at diagnosis, showed increased genioglossus fatigability; this was not observed in patients treated with CPAP. By contrast, patients with obstructive sleep apnoea syndrome showed at diagnosis a higher percentage of type II fibres than controls and patients under CPAP treatment independently of obesity. This difference is mainly due to a predominance of subtype IIb fibre. This difference was not observed in the group of patients treated with CPAP. Genioglossus twitch force was normal in all patients. These results suggest that different pathogenic mechanisms may underlie the development of obstructive sleep apnoea syndrome in obese and nonobese patients. This observation may have potential clinical implications.

Systemic effects of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is characterised by an inappropriate/excessive inflammatory response of the lungs to respiratory pollutants, mainly tobacco smoking. Recently, besides the typical pulmonary pathology of COPD (i.e. chronic bronchitis and emphysema), several effects occurring outside the lungs have been described, the so-called systemic effects of COPD. These effects are clinically relevant because they modify and can help in the classification and management of the disease. The present review discusses the following systemic effects of chronic obstructive pulmonary disease: 1) systemic inflammation; 2) nutritional abnormalities and weight loss; 3) skeletal muscle dysfunction; and 4) other potential systemic effects. For each of these, the potential mechanisms and clinical implications are discussed and areas requiring further research are highlighted.

[Systemic inflammation during exacerbations of chronic obstructive pulmonary disease]

OBJECTIVE

The circulating blood levels of several inflammatory cytokines and acute phase proteins are higher in patients with stable chronic obstructive pulmonary disease (COPD). However, whether or not these inflammatory markers increase during COPD exacerbation or are modified by corticosteroid treatment has not been investigated. The objective of this study was therefore 1) to describe changes in several inflammatory markers in systemic circulation during COPD exacerbation, and 2) to assess the potential effects of corticosteroid treatment during exacerbation.

METHODS

Serum levels of tumor necrosis factor-alpha (TNF-alpha), interleukin 6 (IL-6), interleukin 8 (IL-8) and C-reactive protein (CRP) were determined for 10 patients (65 2 years old) with severe COPD (FEV1 35 4% reference) who were hospitalized for acute respiratory failure (PaO2 57 2 mm Hg; PaCO2 48 3 mm Hg). Blood samples were obtained in the emergency room (before starting intravenous corticosteroid treatment), during the first 24 hours of admission, upon discharge and two months later. Eight healthy non-smokers of a similar age (54 3 years) were also studied as control subjects.

RESULTS

The COPD patients had higher concentrations of IL-6 (5.1 1.6 vs. 1.8 0.5 pg/mL, p < 0.05) and CRP (2.2 0.4 vs. 0.6 0.2 mg/dL, p < 0.005) than did controls, but the concentrations of IL-8 were similar (29 11.3 vs. 34.7 10.3 pg/mL, p = ns). No statistically significant changes were seen either during recovery, in spite of intravenous corticosteroid treatment, or two months after discharge.The ELISA test used was unable to detect TNF-alpha in any of the samples obtained from either patients or controls.

CONCLUSION

The results show that 1) there is evidence of systemic inflammation during exacerbation of COPD, and 2) such systemic inflammation does not appear to be influenced significantly by intravenous corticosteroid treatment.

The activity of cytochrome oxidase is increased in circulating lymphocytes of patients with chronic obstructive pulmonary disease, asthma, and chronic arthritis

We have previously shown that the activity of cytochrome oxidase (CytOx) in skeletal muscle of patients with chronic obstructive pulmonary disease (COPD) was higher than in healthy control subjects. The mechanisms and implications of this observation were unclear. In particular, it was not known if this abnormality can occur also in: (1) cell types other than muscle cells, and (2) other chronic inflammatory diseases. To obtain further insight into these questions, we measured the activity of CytOx in circulating lymphocytes in patients with stable COPD (n = 17), bronchial asthma (n = 6), or chronic arthritis (n = 5), and in healthy control subjects (n = 8). We found that, compared with healthy subjects (280 +/- 117 nKat/microg protein), patients with COPD showed increased CytOx activity (430 +/- 150 nKat/microg protein, p = 0.01) in lymphocytes. Further, this activity was negatively related to the degree of airflow obstruction present in these patients (r = -0.53, p < 0.05). We also found that the activity of CytOx in circulating lymphocytes was higher than normal in patients with chronic arthritis (411 +/- 130 nKat/microg protein, p < 0.05) and, particularly, in patients with bronchial asthma (1,667 +/- 1,027 nKat/microg protein, p < 0.001). These results show that the increased CytOx activity previously reported in skeletal muscle of patients with COPD is also detected in other cell types (such as circulating lymphocytes) and in other chronic inflammatory diseases (such as bronchial asthma and chronic arthritis). The mechanisms and implications of these findings deserve further investigation.

[Respiratory muscle force and resistance in patients with SAHS. The effect of using nighttime CPAP]

During nighttime episodes of obstructive apnea in patients with sleep apnea-hypopnea syndrome (SAHS), repeated and progressive inspiratory efforts are made. Such intense nighttime activity can have a deleterious effect on daytime function of respiratory muscles.

OBJECTIVE

The objective of this study was to evaluate daytime respiratory muscle function in a group of SAHS patients before and after two months of treatment with nighttime continuous positive airway pressure (CPAP).

METHODS

We enrolled 12 patients with SAHS and 10 normal subjects (control group). To evaluate respiratory muscle strength we measured maximum esophageal pressure (Pesmax), transdiaphragmatic pressure (Pdimax) and inspiratory pressure in the mouth (PM). Respiratory muscle resistance was assessed using peak pressure in the mouth (PMPeak), time of tolerance (Tlim) and maximum inspiratory pressure-time index (PTimax). We also analyzed the nighttime function of respiratory muscles during apneic episodes in 10 of the 12 SAHS patients. We propose and define an index of nighttime respiratory muscle activity (RMian) as the product of the tension-time index for the diaphragm observed at the end of nighttime apneic episodes (TTdiapnea) and the apnea-hypopnea index (AHI).

RESULTS

Respiratory muscle strength was similar in the two groups and no changes were observed in SAHS patients after treatment with nighttime CPAP. However, tolerance was lower in SAHS patients (PMpeak--30%, Tlim--31% and PTimax--49%). Two months of nighttime CPAP normalized all three variables in these patients. MRian was related to percent improvement in PMpeak after treatment with nighttime CPAP in SAHS patients (r = 0.66, p < 0.04).

CONCLUSION

SAHS has an adverse effect on the daytime endurance of respiratory muscles that is proportional to the increase of nighttime mechanical muscle activity. The application of nighttime CPAP is restorative, probably because it allows respiratory muscles to rest.

[Diaphragmatic function during exercise in patients with severe COPD]

Ventilatory requirements increase during exercise. The respiratory muscles of patients with chronic obstructive pulmonary disease (COPD) are at a particular disadvantage when dealing with such increased demand. The objective of this study was to evaluate the changes in respiratory muscles brought on by exercise in such patients.

METHODS

Twelve patients with severe CFOPD (FEV1 < 50% ref., 63 +/- 7 years) were enrolled. Breathing patterns and esophageal (Pes and transdiaphragmatic (Pdi) pressures and SaO2 were measured during submaximal exercise/Ecsbmax, 60% of the maximum tolerated load). A sniff maneuver was performed with the patients breathing ambient air with added oxygen to achieve 99% SaO2. We also measured level of FRC by inductive plethysmograph in a subgroup of five patients.

RESULTS

During EXsbmáx, SaO2 decreased (from 95.0 +/- 2.1 to 92.3 +/- 4.0%; p < 0.01); Vt increased (717 +/- 199 to 990 +/- 297 cc, p < 0.01), as did respiratory rate (RR, 17 +/- 6 a 28 +/- 9; p < 0.01). Pes and Pdi were greater at Vt, changing from -12.4 +/- 4.8 to -27.0 +/- 10.1 and 16.6 +/- 6.1 to 30.4 +/- 12.4 cmH2O, respectively (p < 0.01 in both cases), whereas no significant changes were observed for maximal effort (Pesmax, -61.4 +/- 16.5 cersus -65.9 +/- 15.2 cmH2O; Pdimac 89.7 +/- 26.1 versus 81.7 +/- 35.7 cmH2O). Used as a global measure, Pdi/Pdimáx worsened (0.21 +/- 0.12 a 0.42 +/- 0.20; p < 0.01), as dud the diaphragm tension-time (TTdi; 0.07 +/- 0.04 to 0.15 +/- 0.06, p < 0.01). Intrinsic positive end-expiratory pressure (PEEPi) increased an estimated 2.7 +/- 2.1 to 9.4 +/- 5.8 cmH2O (p < 0.001), while FRC (delta 357 +/- 274 ml). Durante el EXsbmáx with oxygen supplementation, SaO2 did not decrease. However supplementation, though Ti/TTOT and maximal pressures remained unchanged.

CONCLUSIONS

Respiratory muscle function changes induced by Exsbmáx seem to relate mainly to a worsening of system mechanics.

Patients with obstructive sleep apnea exhibit genioglossus dysfunction that is normalized after treatment with continuous positive airway pressure

Obstructive sleep apnea syndrome (OSAS) is characterized by repetitive episodes of pharyngeal closure during sleep. The pathogenesis of OSAS is unclear. We hypothesized that the genioglossus (GG), the most important pharyngeal dilator muscle, would be abnormal in patients with OSAS. Further, because treatment with continuous positive airway pressure (CPAP) is very effective clinically in these patients, we investigated the effects of CPAP upon the structure and function of the GG. We studied 16 patients with OSAS (nine of them at diagnosis and seven after having been under treatment with CPAP for at least 1 yr) and 11 control subjects in whom OSAS was excluded clinically. A biopsy of the GG was obtained in each subject, mounted in a tissue bath, and stimulated through platinum electrodes. The following measurements were obtained: maximal twitch tension, contraction time, half-relaxation time, the force-frequency relationship, and the response to a fatiguing protocol. The percentage of type I ("slow twitch") and type II ("fast twitch") fibers was also quantified. Patients with OSAS showed a greater GG fatigability than did control subjects (ANOVA, p < 0.001). Interestingly, this abnormality was entirely corrected by CPAP. Likewise, the percentage of type II fibers was significantly higher in patients with OSAS (59 +/- 4%) than in control subjects (39 +/- 4%, p < 0.001) and, again, these structural changes were corrected by CPAP (40 +/- 3%, p < 0.001). These results show that the function and structure of the GG is abnormal in patients with OSAS. Because these abnormalities are corrected by CPAP, we suggest that they are likely a consequence, not a cause, of the disease.

[The results of the operation of a monitoring unit for home oxygen therapy]

OBJECTIVE

This study aims to a) analyze the prevalence of domiciliary oxygen therapy (DOT) in Mallorca, b) evaluate the cost effectiveness of the DOT monitoring unit, and c) determine the survival of patients with chronic obstructive pulmonary disease who are presently receiving DOT.

METHOD

When the DOT unit was created in April 1994, the situation of all patients receiving DOT in Mallorca was assessed in a transversal study. Over the next three years, these patients were reassessed regularly and all new prescriptions were evaluated (longitudinal study).

RESULTS

Before the unit began work, DOT was prescribed for 71 out of 100,000 inhabitants. DOT was withdrawn from 31% of patients assessed in the transversal study. By the end of the longitudinal study, DOT was being prescribed at a rate of 56 times per 10,000 inhabitants. The activities of the DOT unit brought about annual savings of approximately 38 million pesetas. The number of patients with liquid oxygen and concentrators increased such that the latter has become the main delivery system. The survival of COPD patients with DOT in this study seems to be longer than report.

CONCLUSIONS

a) The prevalence of DOT use in Mallorca before the DOT unit began operating was too high. b) The cost effectiveness of DOT monitoring is positive because DOT use has been optimized and significant savings have ensued (= 38 millions pesetas/year). c) The survival of COPD patients receiving DOT at present appears better than that reported in the literature, possibly related to the greater efficacy of modern treatment.

Expression of adhesion molecules and G proteins in circulating neutrophils in chronic obstructive pulmonary disease

We investigated the expression of adhesion molecules in circulating neutrophils (lymphocyte function-associated antigen-1 [LFA-1], Mac-1, and L-selectin) and endothelial cells (soluble intercellular adhesion molecule-1[sICAM-1]) in 23 patients with stable chronic obstructive pulmonary disease (COPD), 18 subjects with exacerbated COPD, and 23 healthy volunteers. Also, in these circulating neutrophils, we assessed the expression of two G protein subunits (Galphas and Galphai1/2). Compared with control subjects, patients with stable COPD showed increased expression of Mac-1 (p < 0.001) and lower levels of sICAM-1 (p = 0.002); LFA-1 and L-selectin expression was similar in patients and control subjects. During exacerbations, compared with stable patients, the expression of Mac-1 and LFA-1 was reduced (p < 0.001). Finally, the expression of Galphas (but not Galphai1/2) was also reduced (p < 0.001) in circulating neutrophils of patients with COPD, irrespective of the clinical condition of the patient. These results indicate that in patients with COPD: (1) the expression of some neutrophil adhesion molecules (Mac-1) is abnormal, and that this pattern changes during exacerbations; (2) there may be a form of endothelial dysfunction, as suggested by the low sICAM-1 levels; (3) the expression of G protein subunit (Galphas) in circulating neutrophils is downregulated, irrespective of their clinical conditions. Overall, these results indicate the presence of significant systemic abnormalities in COPD.

Cytochrome oxidase activity and mitochondrial gene expression in skeletal muscle of patients with chronic obstructive pulmonary disease

Several recent studies have suggested that skeletal muscle bioenergetics are abnormal in patients with chronic obstructive pulmonary disease (COPD). This study investigates the activity of cytochrome oxidase (COX), the terminal enzyme in the mitochondrial electron transport chain, and the expression of two mitochondrial DNA genes related to COX (mRNA of subunit I of COX [COX-I] and the RNA component of the 12S ribosomal subunit [12S rRNA]), in quadriceps femoris muscle biopsies obtained from COPD patients with various degrees of arterial hypoxemia, and from healthy sedentary control subjects of similar age. The activity of COX was measured spectrophotometrically in fresh tissue at 37 degrees C with excess substrate. RNA transcripts were measured using reverse transcription and polymerase chain reaction. The measurements of mRNA COX-I and 12S rRNA were normalized to the mRNA of actin, which is a housekeeping gene not influenced by hypoxia. We found that, compared with control subjects, COPD patients with chronic respiratory failure (PaO2 < 60 mm Hg) showed increased COX activity (p < 0.05). Further, the activity of COX was inversely related to arterial PO2 value (Rho -0.59, p < 0.01). The COX-I mRNA content was not different between patients and control subjects but patients with chronic respiratory failure had higher levels of 12S rRNA (p < 0.05), which were again inversely related to PaO2 (Rho -0.49, p < 0.05). These results indicate that the activity of COX is increased in skeletal muscle of patients with COPD and chronic respiratory failure, and they suggest that this is likely regulated at the translational level by increasing the number of mitochondrial ribosomes.

Structure and function relationships of the respiratory muscles

Potential relationships between the structure of the diaphragm and external intercostals and several indices of respiratory muscle function, lung function and nutrition in 27 patients (61+/-10 yrs of age) subjected to thoracotomy as a result of a lung neoplasm have been investigated. Prior to surgery the nutritional status of the patients was assessed and lung function (spirometry, lung volumes, transfer factor of the lungs for carbon monoxide, arterial blood gases) and respiratory muscle function (maximal inspiratory pressure (MIP) and diaphragmatic function were measured). Biopsies of the diaphragm (and external intercostals) were obtained during surgery. On average, patients showed mild airflow limitation (forced expiratory volume in one second (FEV1), 70+/-14% of predicted value, FEV1/forced vital capacity (FVC), 70+/-9%) with some air trapping (residual volume (RV), 139+/-50% pred) and normal gas exchange (arterial oxygen tension (Pa,O2), 11.3+/-1.33 kPa (85+/-10 mmHg)) and arterial carbon dioxide tension (Pa,CO2) 5.4+/-0.5 kPa (40.6+/-4 mmHg). MIP was 77+/-25% pred; maximal transdiaphragmatic pressure was 90+/-27 cmH2O. Most morphometric measurements of the diaphragm and external intercostals were within the range of values reported previously in other skeletal muscles. The size of the fibres of these two respiratory muscles was positively related (p<0.05) to MIP (% pred). There were no significant relationships between the structure of both muscles and nutritional status or any index of lung function. In conclusion, in the population studied, the fibre size of the diaphragm and external intercostals appears to relate to their ability to generate force.

A new bronchoscopic technique for the diagnosis of bacterial pneumonia in HIV-positive patients

The aim of the present study was to evaluate in HIV-positive patients with bacterial pneumonia, the diagnostic value of a new endoscopic technique that uses a single catheter to perform a telescopic plugged catheter (TPC) followed by a modified protected bronchoalveolar lavage (mpBAL). Fifty-eight HIV-positive patients with respiratory infection were included in the study. Samples from TPC and mpBAL were cultured quantitatively. Standard bronchoalveolar lavage was performed to rule out opportunistic infections. According to the clinical and microbiological results, patients were classified in the study group (27 with bacterial pneumonia) or the control group (31 without bacterial pneumonia). Sensitivity of TPC was 56% [95% confidence intervals (CI) 37-75%] and its specificity was 100%; these figures were 56% (CI, 37-75%) and 94% (CI, 86-100%) for mpBAL. When both techniques were assessed together, sensitivity increased to 70% (CI, 53-87%). The use of a single catheter reduced the cost of the originally described pBAL procedure by approximately 50%. The use of a single catheter to perform a TPC followed by a mpBAL can improve the diagnostic yield in HIV-positive patients with bacterial pneumonia, and reduces its cost.

Continuous positive airway pressure is effective in treating upper airway oedema

The case of a patient with diffuse idiopathic skeletal hyperostosis (DISH) and upper airway oedema, is described. The patient presented with alveolar hypoventilation and obstructive apnoeas during sleep. Intravenous steroids (methylprednisolone, 160 mg.day-1) for 5 days did not reduce the oedema. However, it was rapidly reversed by the use of nasal continuous positive airway pressure (nCPAP). In addition, daytime pulmonary gas exchange was improved and sleep apnoea abolished. This beneficial effect made tracheostomy unnecessary. This case report suggests that CPAP can be a potentially useful therapeutic alternative to tracheostomy in the clinical management of upper airway oedema.

Structure of the latissimus dorsi muscle and respiratory function

The aim of this study was to evaluate whether respiratory function influences the structure of the latissimus dorsi muscle (LD). Twelve patients (58 +/- 10 yr) undergoing thoracotomy were studied. Lung and respiratory muscle function were evaluated before surgery. Patients showed a forced expired volume in 1 s (FEV1) of 67 +/- 16% of the reference value, an FEV1-forced vital capacity ratio of 69 +/- 9%, a maximal inspiratory pressure of 101 +/- 21% of the reference value, and a tension-time index of the diaphragm (TTdi) of 0.04 +/- 0.02. When patients were exposed to 8% CO2 breathing, TTdi increased to 0.06 +/- 0.03 (P < 0.05). The structural analysis of LD showed that 51 +/- 5% of the fibers were type I. The diameter was 56 +/- 9 microns for type I fibers and 61 +/- 9 microns for type II fibers, whereas the hypertrophy factor was 87 +/- 94 and 172 +/- 208 for type I and II fibers, respectively. Interestingly, the histogram distribution of the LD fibers was unimodal in two of the three individuals with normal lung function and bimodal (additional mode of hypertrophic fibers) in seven of the nine patients with chronic obstructive pulmonary disease. An inverse relationship was found between the %FEV1-forced vital capacity ratio and both the diameter of the fibers (type I: r = -0.773, P < 0.005; type II: r = -0.590, P < 0.05) and the hypertrophy factors (type I: r = -0.647, P < 0.05; type II: r = -0.575, P = 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

[Usefulness of respiratory endoscopy in patients with severe rhonchi and/or sleep apnea syndrome]

BACKGROUND

Obstruction of the upper respiratory tract is the most common cause of the sleep apnea syndrome (SAS). Different methods have been used to localize this obstruction and give the appropriate treatment. The aim of this study was to evaluate the usefulness of respiratory endoscopy performed during arousal to identify the site and cause of the obstruction in patients with severe rhoncopathy and/or SAS.

METHODS

Sixty-eight patients with acute rhoncopathy were included in the study with 36 also fulfilling polysomnographic criteria of SAS (36%). The endoscopy was performed via the upper respiratory tract with inspiratory collapse at each level being evaluated in both easy respiration and during the Müller manoeuver.

RESULTS

The site and cause of the obstruction was identified in 61 patients (90%, CI 95%, 79.9 +/- 95.8). In most cases the Müller manoeuver best demonstrated the collapse. The predominant obstruction was in the nasopharyngeal region (72%, mainly associated to changes in soft palate), followed by obstruction in the oropharyngeal region at the base of the tongue (29%). Multiple localization of the obstruction was observed in 19 patients.

CONCLUSIONS

Endoscopy performed during arousal may allow the identification of the site and cause of obstruction in most of the patients with rhoncopathy and sleep apnea syndrome, thus aiding in the selecting the most adequate treatment for the patient.

[Neutrophilia in the bronchoalveolar lavage of patients with AIDS and Pneumocystis carinii pneumonia. Reflections on its prognostic value in the Spanish setting]

The prognostic value of neutrophilia (> 5%) in bronchoalveolar lavage (BAL) in our context is studied in 21 patients with AIDS and Pneumocystis carinii pneumonia. Neutrophilia does not seem to be a good prognostic indicator in our context. We have found this condition, with a mean of 6 +/- 4%, in only 33% of our sample. The sensitivity of this parameter with respect to risk of death was very low (25%), while specificity was moderate (65%). In contrast with what has been reported in studies done with Anglo-Saxon populations, neutrophilia in BAL is probably of little prognostic use in our context. This may be due to various factors, among them the type of population (most being intravenous drug users) and the therapeutic protocol (early empirical treatment).

Simplified exercise test for the initial differential diagnosis of Pneumocystis carinii pneumonia in HIV antibody positive patients

BACKGROUND

This study was designed to evaluate the usefulness of a simplified exercise test in the differential diagnosis of Pneumocystis carinii pneumonia (PCP).

METHODS

Forty five subjects with antibodies against the human immunodeficiency virus (HIV) and pneumonia were included and divided into two groups: those with PCP and those with "other pneumonias" (non-PCP). The test involved pedalling for two minutes on a stretcher bed and was considered positive if SaO2 decreased by at least 3%.

RESULTS

During the exercise the mean(SE) SaO2 fell in patients with PCP from 88(4)% to 84(3)%, p < 0.01, whilst it improved slightly in subjects with non-PCP from 91(1)% to 93(3)%, p < 0.05. Sensitivity was 77% and specificity 91%.

CONCLUSIONS

This simple test seems potentially useful for the initial investigation of HIV antibody positive patients with pneumonia.

Probable pentamidine-induced acute pancreatitis

OBJECTIVE

To report a case of probable pentamidine-induced acute pancreatitis.

CASE SUMMARY

A patient was hospitalized because of fever, dyspnea, and productive cough. Chest X-ray revealed diffuse alveolar infiltrates, and the examination of bronchoalveolar lavage demonstrated the presence of Pneumocystis carinii. Intravenous cotrimoxazole was administered but the patient's condition did not improve. As secondary leukopenia appeared, the treatment was changed to pentamidine isethionate 4 mg/kg/d i.v. On day 5 of this new therapy, the patient experienced abdominal pain, and both blood and urine amylase concentrations raised to 330 U/L and 3960 U/L, respectively. The patient died 48 hours later, and signs of acute pancreatitis were observed in necropsy.

DISCUSSION

With reference to a classical method for estimating the probability of adverse drug reactions, a probable relationship between pentamidine therapy and acute pancreatitis was found in this patient. Furthermore, no alternative causes of pancreatitis were present.

CONCLUSIONS

It is likely that pentamidine administration in our patient resulted in an acute episode of pancreatitis. Serum and urine amylase concentrations should be monitored in patients receiving this drug.

Pneumatoceles and pneumothorax after Pneumocystis carinii pneumonia

Pneumocystis carinii pneumonia (PCP) is common in patients with AIDS. The usual chest X-ray pattern is a diffuse interstitial pulmonary infiltrate. Nevertheless, unusual roentgenographic forms can appear. A patient with PCP that resulted in pneumatoceles and a further pneumothorax is described.

[Antigenic response against PPD and antigen 60 in tubercular patients: single antigen versus the combined test]

We analyze serum samples from 70 patients with pulmonary tuberculosis and 50 healthy individuals. The antigenic activity (IgG) against protein purified antigen (PPD) and antigen 60 (A60) from M. tuberculosis. Thirteen patients were also HIV infected, and three patients had AIDS defined by the presence of disseminated tuberculosis. The test using antigen alone showed a 77% sensitivity and 74% specificity when PPD is used. When A60 was used, both values improved (81% sensitivity, 94% specificity). The use of a combined test (PPD and A60) improves the sensitivity (89%) but reduces the specificity (82%). The HIV infected patients showed similar responses to those of other patients. The combined use of different antigens might be useful for diagnosing tuberculosis.

[Usefulness of CT scan in the diagnosis of pulmonary aspergilloma]

Early diagnosis and precise anatomical localization of aspergillomas are essential for an effective treatment of their complications. We have evaluated the usefulness of thorax CT scan in the fulfillment of these objectives. Nine consecutive patients were studied with a presumable diagnosis of pulmonary aspergilloma. A thorax CT scan was performed in all patients (sections every 5 to 10 mm) in lying position and with lateral mobilizations. This technique allowed to rule out as fibrotic lesions some of the images previously attributed to mycetomas by conventional X-ray. On the other hand it helped to identify small size aspergillomas, to precise their localization and to demonstrate the possible communication between the main cavity and bronchial tree. In three patients who died in the period immediately following the study an excellent correlation between CT scan and underlying pathological lesions was observed.

[Dysphagia as the form of presentation of Forestier-Rotés disease]

We present the case of a 73-year-old patient suffering dysphagia secondary to cervical osteophytosis as the clinical presentation of Forestier-Rotés disease. Although this is a frequent disease, there are few cases of dysphagia secondary to this condition it being the initial symptom exceptional. The diagnostic methodology is commented emphasizing cervical CT scan as well as the therapeutic attitude, suggesting starting with a conservative treatment since surgery is not always successful.