Evaluation of Renin and Soluble (Pro)renin Receptor in Patients with IPF. A Comparison with Hypersensitivity Pneumonitis.

INTRODUCTION: Idiopathic pulmonary fibrosis (IPF) is a lethal disease with an unclear pathogenic mechanism. Components of the renin-angiotensin system (RAS) have a role in the pathogenesis of IPF, specifically, the aspartyl protease renin acts as a profibrotic factor in the lung. However, the concentration of the RAS components renin and soluble (pro)renin receptor (sPRR) have not been previously evaluated neither in serum nor in bronchoalveolar lavage fluid (BAL) of patients with IPF or chronic Hypersensitivity pneumonitis (cHP), a disease which may be confused with IPF. METHODS: The serum levels of renin [IPF patients (n = 70), cHP patients (n = 83), and controls (n = 26)] and sPRR [IPF (n = 28), cHP (37), and controls (n = 20)] were measured by ELISA. Renin was also quantified in BALs of IPF patients and controls by Western blot. RESULTS: We found that the levels of renin were higher in serum samples from IPF patients when compared with cHP patients and controls. Furthermore, BALs from IPF patients had more renin than BALs from controls. Unlike renin, the serum levels of sPRR were lower in IPF and cHP patients than in control individuals. CONCLUSIONS: The high levels of renin in sera and BALs of IPF patients suggest that renin might play a major role in the pathogenesis of IPF. Results from BAL confirm that renin is produced locally in the lung. Serum levels of renin could be used to differentiate IPF from cHP.

MMP2 Polymorphism Affects Plasma Matrix Metalloproteinase (MMP)-2 Levels, and Correlates with the Decline in Lung Function in Hypersensitivity Pneumonitis Positive to Autoantibodies Patients.

Among hypersensitivity pneumonitis (HP) patients have been identified who develop autoantibodies with and without clinical manifestations of autoimmune disease. Genetic factors involved in this process and the effect of these autoantibodies on the clinical phenotype are unknown. Matrix metalloproteinases (MMPs) have an important role in architecture and pulmonary remodeling. The aim of our study was to identify polymorphisms in the MMP1, MMP2, MMP9 and MMP12 genes associated with susceptibility to HP with the presence of autoantibodies (HPAbs+). Using the dominant model of genetic association, comparisons were made between three groups. For rs7125062 in MMP1 (CC vs. CT+TT), we found an association when comparing groups of patients with healthy controls: HPAbs+ vs. HC (p < 0.001, OR = 10.62, CI 95% = 4.34 - 25.96); HP vs. HC (p < 0.001, OR = 7.85, 95% CI 95% = 4.54 - 13.57). This rs11646643 in MMP2 shows a difference in the HPAbs+ group by the dominant genetic model GG vs. GA+AA, (p = 0.001, OR = 8.11, CI 95% = 1.83 - 35.84). In the linear regression analysis, rs11646643 was associated with a difference in basal forced vital capacity (FVC)/12 months (p = 0.013, = 0.228, 95% CI95% = 1.97 - 16.72). We identified single-nucleotide polymorphisms (SNPs) associated with the risk of developing HP, and with the evolution towards the phenotype with the presence of autoantibodies. Also, to the decrease in plasma MMP-2 levels.

Small airway dysfunction in chronic hypersensitivity pneumonitis.

BACKGROUND AND OBJECTIVE: Lung biopsies from patients with hypersensitivity pneumonitis (HP) have demonstrated small airway (SA) involvement, but there is no information concerning SA function in HP, and it is unknown whether pharmacological treatment could modify its function. SA function in patients with chronic HP using ultrasonic pneumography (UPG) and impulse oscillometry (IOS) was explored. We also compared initial results with those obtained after 4 weeks of standardized treatment with azathioprine and prednisone. METHODS: The study group consisted of adults with recent diagnoses of HP. All patients completed UPG, IOS, spirometry, body plethysmography, single-breath carbon monoxide diffusing capacity (DLCO ) and the 6-min walk test (6MWT). The fraction of exhaled nitric oxide (FENO ) was obtained to assess eosinophilic airway inflammation. Measurements were taken at diagnosis and after 4 weeks of treatment. RESULTS: A total of 20 consecutive patients (16 women) with chronic HP participated in the study. Median age was 50 years (interquartile range (IQR): 42-54). At diagnosis, the UPG phase 3 slope was abnormally high, consistent with maldistribution of ventilation. For IOS, all patients had low reactance at 5 Hz (X5) and elevated reactance area (AX) reflecting low compliance, and only eight (40%) patients had elevated R5 (resistance at 5 Hz (total)) and R5-20 (resistance at 5 Hz-resistance at 20 Hz (peripheral)) attributed to SA resistance. In contrast, FENO parameters were within normal limits. After treatment, forced vital capacity (FVC), the 6-min walk distance and the distribution of ventilation showed significant improvement, although DLCO did not. CONCLUSION: Patients with chronic HP have SA abnormalities that are partially revealed by the UPG and IOS tests. Lung volumes, but not gas exchange, improved after treatment with azathioprine and prednisone.

A haemodynamic study of pulmonary hypertension in chronic hypersensitivity pneumonitis.

Chronic hypersensitivity pneumonitis is a common fibrotic interstitial lung disease. The prevalence of pulmonary hypertension diagnosed by right heart catheterisation and its cardiopulmonary function findings in patients with chronic hypersensitivity pneumonitis are unknown. Consecutive symptomatic patients with chronic hypersensitivity pneumonitis were prospectively evaluated. All patients were submitted to right heart catheterisation, pulmonary function testing, a 6-min walk test, echocardiography, blood gas determination and N-terminal pro-brain natriuretic peptide analyses. Nonhypoxaemic patients also underwent incremental cardiopulmonary exercise testing. 50 patients underwent right heart catheterisation; 25 (50%) of these had pulmonary hypertension and 22 (44%) had a pre-capillary haemodynamic pattern. The patients with pre-capillary pulmonary hypertension had lower forced vital capacity (mean ± sd 50 ± 17% versus 69 ± 22% predicted, p<0.01), carbon monoxide diffusing capacity (37 ± 12% versus 47 ± 14% predicted, p<0.01), arterial oxygen tension (median (interquartile range) 59.0 (47.8-69.3) versus 73.0 (62.2-78.5) mmHg, p<0.01) and saturation after the 6-min walk test (78 ± 8% versus 86 ± 7%, p<0.01). In pre-capillary pulmonary hypertension, oxygen uptake was also lower at the anaerobic threshold (41 ± 11% versus 50 ± 8% predicted, p=0.04) and at peak exercise (12.8 ± 1.6 versus 15.0 ± 2.5 mL · kg(-1) · min(-1), p=0.02). Pre-capillary pulmonary hypertension is common in symptomatic chronic hypersensitivity pneumonitis and is related to interstitial lung disease severity. Additionally, pulmonary hypertension is more prevalent in hypoxaemic patients with impaired lung function and exercise capacity.

Linear and nonlinear analysis of base lung sound in extrinsic allergic alveolitis patients in comparison to healthy subjects.

OBJECTIVE: Pulmonary disorders are frequently characterized by the presence of adventitious sounds added to the breathing or base lung sound (BLS). The aim of this work was to assess the features of BLS in extrinsic allergic alveolitis (EAA) patients in comparison to healthy subjects, applying linear and nonlinear analysis techniques. METHODS: We investigated the multichannel lung sounds on the posterior chest of 16 females, 8 healthy and 8 EAA patients, when breathing at 1.5 L/s. BLS linear features were obtained from the power spectral density (PSD) while nonlinear features were extracted by the concepts of irregularity and complexity, i.e., spectral, sample and multiscale entropy. RESULTS: The results demonstrated that spectral percentiles of BLS were lower in EAA patients than in healthy subjects but statistical significance (p<0.05) was obtained only for expiration at the left apical and both basal regions. Also, the maximum amplitude of the PSD in patients reached statistical significance ( p < 0.05) for the expiratory phase at basal regions. In the case of nonlinear techniques, significant lower values ( p < 0.05) were obtained for EAA patients during both respiratory phases at left apical and both basal regions. CONCLUSION: In conclusion, we found that BLS in chronic EAA patients is characterized by lower spectral percentiles, lower irregularity and lower complexity than in healthy subjects suggesting the feasibility of its clinical usefulness by screening its temporal alteration.

PSMB8 (LMP7) but not PSMB9 (LMP2) gene polymorphisms are associated to pigeon breeder's hypersensitivity pneumonitis.

Hypersensitivity Pneumonitis (HP) is a lung inflammatory disorder caused by inhalation of organic particles by a susceptible host. However, only a small proportion of individuals exposed to HP-associated antigens develop the disease, suggesting that additional host/environmental factors may play a role. We have previously found that genetic susceptibility associated to the major histocompatibility complex (MHC) plays an important role in this disease. The low molecular weight proteosome (LMP, currently named PSMB) genes code for subunits of the proteosome, a multimeric enzymatic complex that degrades proteins into peptides in order to be presented in the MHC class I pathway. We hypothesized that polymorphisms in PSMB8 or PSMB9 genes could be involved in the susceptibility to HP. Thus, in this study we analyzed the polymorphic site at amino acid position 60 (Arg/His) of the fourth exon in the PSMB9 gene and the amino acid position 49 (Gln/Lys) in the second exon of PSMB8 gene in 50 Mexican patients with HP and 50 healthy ethnically matched controls. PSMB typing was performed using polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP). Our results demonstrated that HP patients had a significant increase of the PSMB8 KQ genotype frequency (OR = 7.25, CI = 2.61-21.3; p = 0.000034). No differences were found in the distribution of PSMB9 alleles/genotypes. However, PSMB9-RH/PSMB8 KQ haplotype was significantly increased in HP patients (OR = 6.77, CI = 1.34-65.31, p < 0.02). These findings suggest that PSMB8 KQ genotype could increase the risk to develop hypersensitivity pneumonitis.

[Clinical interpretation for the pressure-flow relationships in extrinsic allergic alveolitis and in interstitial lung disease pulmonary hypertension patients. Should we care for the lung, the pulmonary artery pressure or both?]. / Interpretación clínica de la relación presión-flujo en enfermos con alveolitis alérgica extrínseca con neumopatía intersticial crónica e hipertensión pulmonar. Debemos tratar la hipertensión, la patología pulmonar o ambas?

OBJECTIVES: We sought to analyze exercise-derived mean pulmonary artery pressure (mPAP)-cardiac index (CI) relationship to expand the concepts regarding its nature and to better identify pulmonary hemodynamic responders to acute oxygen breathing (AO2B-99.5%) and to hydralazine (H) in extrinsic allergic alveolitis (EAA) and chronic interstitial lung disease (CILD) pulmonary hypertension (PH) patients. MATERIAL AND METHODS: mPAP/CI and extrapolated pressure (Pext) to zero flow were obtained while breathing room air (BRA) and under AO2B-99.5% in 38 stable (EAA (n = 14) and CILD (n = 24)) patients with resting and exercising PH. Hemodynamic characteristics were analyzed for the entire cohort and separate for EAA and CILD patients. AO2B-99.5% was tested in cohorts, H only in CILD and the effect of long-term corticosteroid treatment in EAA patients. Lung biopsies (LB) were obtained to evaluate the inflammatory-fibrosis stage and the degree of vascular lesion in the entire cohort. RESULTS: LB studies reveal a predominant stage of inflammation associated with grade-I vascular lesion for EAA patients. A predominant stage for fibrosis (although moderate) over inflammation associated with grade-II vascular lesions were documented for CILD patients. mPAP/CI abnormal location were associated with hypoxemia/decreased mixed venous-PO2 and lung mechanics abnormalities for both cohorts. An abnormal slope (Sp: 4.13; 95% CI: 3.42-4.84 mmHg/L/min/m2) and a normal Pext value (7 +/- 1.9 mmHg) were found for EAA patients. On the contrary, a normal slope (Sp: 1.22; 95% CI: 0.47-1.99 mmHg/L/min/m2) and an abnormal Pext value (19.7 +/- 3.5 mmHg) were found for CILD patients. Hemodynamic conditions that did not change for the Sp (4.0; 95% CI: 3.18-4.82 mmHg/L/min/m2); however, were associated with a statistical significant decrease in parallel for mPAP/CI during AO2B-99.5% when compared to BRA (p < 0.01), although not to normal slope values (0.96; 95% CI: 0.41-1.37) or mPAP/CI location. For CILD patients, during AO2B-99.5% no change for the slope, for Pext and mPAP/CI location in relation to BRA were observed. Under the effect of H, no change for the previous mentioned hemodynamic findings were found in relation to the control condition for CILD patients. After long-term corticosteroid treatment, normalization for mPAP/CI location and for the slope value (1.6; 95% CI: 0.91-2.29 mmHg/L/min/m2) were associated with lung mechanics and blood-gas exchange normalization were documented in EAA patients. CONCLUSIONS: When mPAP/CI exercise derived is analyzed, valuable information for linear-pulmonary vascular resistance-(LPVR) could be obtained for EAA and CILD-PH patients. mPAP/CI-r abnormalities not always reflect "pure arteriolar" increased LPVR for EAA and CILD patients. H is not useful as an adjunct vasodilator therapy for CILD-PH patients. AO2B-99.5% decrease right ventricular afterload for EAA patients, although not to normal. Complete reversibility for PH could result after long-term corticosteroid treatment. We conclude that treatment should focus mainly on the lung and not in the pulmonary artery pressure in interstitial lung disease PH patients.

In vivo hydroquinone exposure impairs allergic lung inflammation in rats.

Hydroquinone (HQ) is naturally found in the diet, drugs, as an environmental contaminant and endogenously generated after benzene exposure. Considering that HQ alters the immune system and its several source of exposures in the environment, we hypothesized that prolonged exposure of HQ could affect the course of an immune-mediated inflammatory response. For this purpose, male Wistar rats were intraperitoneally exposed to vehicle or HQ once a day, for 22 days with a 2-day interval every 5 days. On day 10 after exposure with vehicle or HQ, animals were ovalbumin (OA)-sensitized and OA-aerosolized challenged on day 23. HQ exposure did not alter the number of circulating leukocytes but impaired allergic inflammation, evidenced by lower number of leukocytes in the bronchoalveolar lavage fluid 24h after OA-challenge. Reduced force contraction of ex vivo tracheal segments upon OA-challenge and impaired mesentery mast cell degranulation after in situ OA-challenge were also detected in tissues from HQ exposed animals. The OA-specificity on the decreased responses was corroborated by normal trachea contraction and mast cell degranulation in response to compound 48/80. In fact, lower levels of circulating OA-anaphylactic antibodies were found in HQ exposed rats, as assessed by passive cutaneous anaphylaxis assay. The reduced level of OA-anaphylactic antibody was not dependent on lower number or proliferation of lymphocytes. Nevertheless, lower expression of the co-stimulatory molecules CD6 and CD45R on OA-activated lymphocytes from HQ exposed rats indicate the interference of HQ exposure with signaling of the humoral response during allergic inflammation. Together, these data indicate specific effects of HQ exposure manifested during an immune host defense.

Immune-complex alveolitis in the rat: evidence for platelet activating factor and leukotrienes as mediators of the vascular lesions.

In the present study we investigated the involvement of lipid mediators in an experimental model of immune-complex alveolitis induced in rat lungs by intrabronchial instillation of rabbit antibodies to ovalbumin followed by i.v. injection of the antigen. It was found that the reaction did not induce detectable oedema, as measured by the dry:wet weight ratio. A marked influx of neutrophils was observed in the bronchoalveolar lavage fluid, progressing from 6 to 24 h in parallel with the development of haemorrhagic lesions in lung parenchyma. The intensity of these lesions, evaluated by the concentration of extravascular haemoglobin, was not significantly affected by pretreatment of the animals with a cyclo-oxygenase inhibitor (indomethacin), a thromboxane inhibitor (econazole) or a thromboxane antagonist (L-655,240). However, the antagonists of platelet activating factor (PAF), WEB-2086 and BN-52021, and the lipoxygenase inhibitors, nor-dihydroguaiaretic acid and L-663,536, all significantly inhibited the haemorrhagic lesions. A peptide leukotriene antagonist (L-660,711) had no effect. Furthermore, the PAF antagonists inhibited the levels of LTB4, but not of PGE2 and thromboxane, released into the bronchoalveolar space 1 h after induction of the reaction. These results suggest that the haemorrhagic lesions in this model of immune-complex alveolitis are mediated by PAF and leukotrienes, possibly LTB4.

Increased levels of leukotriene c4 in bronchoalveolar lavage from patients with pigeon breede's disease

En este estudio se midió la concentración de Leucotriene C4 (LTC4) y de complejos inmunes en el líquido obtenido po lavado broncoalveolar en pacientes con neumonitis por hipersensibilidad inducida por antígeno aviario (n=14), fibrosis pulmonar idiopática (n=5), neumonitis secundaria a artritis reumatoide (n=5), y en sujetos normales (n=4). Se encontró que los pacientes con neumonitis por hipersensibilidad tenían valores de LTC4 maiores que los sujetos normales (mediana, 5 ng/ml y 2.25 ng/ml, respectivamente) con p < 0.05, mientras que los pacientes con fibrosis pulmonar y artritis reumatóide tenían intermedios. Además, de 5 pacientes con neumonitis por hipersensibilidad y LTC4 < 4 ng/ml sólo uno tenía complejos inmunes elevados, mientras que de 9 pacientes con esta enfermedad y LTC4 > 4 ng/ml, 8 tenían complejos inmunes elevados (p < 0.03). Estos resultados sugieren que probablemente el LTC4 constituye uno de los mediadores biológicos que participan en la inflamación pulmonar de la neumonitis por hipersensibilidad inducida por antígeno aviario