Bronchial responsiveness and angiotensin-converting enzyme gene polymorphism in sarcoidosis patients

Activatable Probes for Ratiometric Imaging of Endogenous Biomarkers In Vivo

Dynamic variations in the concentration and abnormal distribution of endogenous biomarkers are strongly associated with multiple physiological and pathological states. Therefore, it is crucial to design imaging systems capable of real-time detection of dynamic changes in biomarkers for the accurate diagnosis and effective treatment of diseases. Recently, ratiometric imaging has emerged as a widely used technique for sensing and imaging of biomarkers due to its advantage of circumventing the limitations inherent to conventional intensity-dependent signal readout methods while also providing built-in self-calibration for signal correction. Here, the recent progress of ratiometric probes and their applications in sensing and imaging of biomarkers are outlined. Ratiometric probes are classified according to their imaging mechanisms, and ratiometric photoacoustic imaging, ratiometric optical imaging including photoluminescence imaging and self-luminescence imaging, ratiometric magnetic resonance imaging, and dual-modal ratiometric imaging are discussed. The applications of ratiometric probes in the sensing and imaging of biomarkers such as pH, reactive oxygen species (ROS), reactive nitrogen species (RNS), glutathione (GSH), gas molecules, enzymes, metal ions, and hypoxia are discussed in detail. Additionally, this Review presents an overview of challenges faced in this field along with future research directions.

Cough in Sarcoidosis

Sarcoidosis is a granulomatous disorder that frequently affects the lungs. Cough is commonly reported by patients and can significantly reduce health-related quality of life. The mechanism of cough is unknown but airway inflammation, mechanical distortion from pulmonary fibrosis and disruption of the vagus nerve are possible. Recent evidence suggests cough reflex hypersensitivity may also be an important mechanism and predictor of the frequency of cough. The investigation of cough should evaluate common causes such as asthma, gastro-oesophageal reflux and rhinitis. In patients with suspected cough due to sarcoidosis, a trial of corticosteroids should be considered. The severity of cough should be evaluated with validated outcome measures such as visual analogue scales, cough severity diary, health-related quality of life questionnaires such as the Leicester Cough Questionnaire and objective cough monitors. Future studies are needed to identify targets for therapeutic development.

Role of genetic polymorphisms in ACE and TNF-alpha gene in sarcoidosis: a meta-analysis

A great number of association studies have been performed to identify the genes involved in the etiology and prognosis of sarcoidosis. We performed a systematic review of case-control studies through the PubMed database and evaluated them for a possible inclusion into a meta-analysis in order to assess whether the reported genetic polymorphisms are the risk factors of sarcoidosis. Case-control studies with clear diagnostic criteria and interventions were included. Only investigations of a single polymorphism/gene involvement in sarcoidosis reported more than five times were selected. Aggregating data from 12 studies on ID/ACE polymorphisms, the odds ratio (OR) for sarcoidosis, if the polymorphism was considered under the dominant genetic model, was not significantly increased: 1.19 (95% CI 0.98-1.43); OR under the recessive model was 1.20 (95% CI 0.98-1.46). In seven case-control studies on -308/TNF-alpha polymorphism, the OR for sarcoidosis if the polymorphism considered under the dominant genetic model was significantly increased at 1.47 (95% CI 1.03-2.08); the OR under the recessive model was 1.39 (95% CI 0.67-2.90). In conclusion, the results showed that the TNF-alpha genotype could be a significant risk factor for sarcoidosis, whereas the risk of sarcoidosis due to the ACE genotype was not substantially elevated.

Polymorphism of the angiotensin-converting enzyme gene affects the outcome of acute respiratory distress syndrome

OBJECTIVE

There has been increasing evidence that angiotensin II may play an important role in the pathogenesis and in the evolution of acute lung injury. It was therefore hypothesized that polymorphisms of the angiotensin-converting enzyme gene affects the risk and outcome of acute respiratory distress syndrome (ARDS).

DESIGN

Prospective, observational study.

PATIENTS AND SETTINGS

The ARDS group consisted of 101 patients treated at the medical intensive care unit; the control groups consisted of 138 "at-risk" patients treated at the medical intensive care unit due to acute respiratory failure but did not meet the ARDS criteria throughout the hospital course, and 210 non-at-risk subjects.

INTERVENTION

None.

MEASUREMENTS AND MAIN RESULTS

The ARDS patients and control subjects were genotyped for the insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme gene. Association of the polymorphism and the risk and the outcome of ARDS was analyzed. There was no significant difference in the frequencies of the genotypes between the ARDS, at-risk, and non-at-risk groups. The 28-day mortality rates were significantly different between the three angiotensin-converting enzyme genotypes (42%, 65%, and 75% for II, ID, and DD, respectively; p = .036). Survival analysis showed that the II genotype favorably affected 28-day survival (hazard ratio, 0.46; 95% confidence interval, 0.26-0.81; p = .007), whereas ARDS caused by hospital-acquired pneumonia had a negative effect (hazard ratio, 2.34; 95% confidence interval, 1.25-4.40; p = .008). The II genotype (hazard ratio, 0.53; 95% confidence interval, 0.32-0.87; p = .012) and ARDS caused by hospital-acquired pneumonia (hazard ratio, 2.13; 95% confidence interval, 1.24-3.68; p = .006) were also significant prognostic factors for the in-hospital mortality.

CONCLUSIONS

The angiotensin-converting enzyme I/D polymorphism is a significant prognostic factor for the outcome of ARDS. Patients with the II genotype have a significantly better chance of survival. This study did not show an increased risk for ARDS in Chinese patients with the D allele.

Obstructive sarcoidosis

Sarcoidosis is a systemic granulomatous disease that frequently involves the lung. Although classically thought of as a restrictive lung disease, airway obstruction has become a recognized feature of the disease in the past years. Sarcoidosis can affect the airway at any level and when the involvement includes small airways, it can resemble more common obstructive airway diseases, such as asthma and chronic bronchitis. Pulmonary function testing and high-resolution computerized tomography of the chest are two important tools to evaluate the presence and extent of airway obstruction in sarcoidosis. Pharmacologic options for the treatment of obstructive sarcoidosis are, in large part, not supported by large, randomized clinical trials. In severe cases of bronchostenosis owing to sarcoidosis granuloma or extrinsic compression from intrathoracic lymphadenopathy, interventional bronchoscopy has successfully been performed, although repeated procedures are usually required. Lung transplantation is an ultimate option in selected patients with late-stage fibrotic disease.

Angiotensin-converting enzyme gene polymorphisms in patients with pulmonary sarcoidosis: impact on disease severity

Angiotensin converting enzyme (ACE) is a metallopeptidase with a key function in the regulation of blood pressure and volume. The ACE1 gene, on chromosome 17, contains a insertion/deletion (I/D) polymorphism in intron 16. The D allele of this polymorphism is linked with raised serum ACE (sACE) levels. Sarcoidosis is a systemic disease of granulomatous inflammation that primarily affects the lung and lymph system. It is often accompanied by elevated sACE related to ACE production from granuloma cells. The ACE I/D polymorphism has been tested for association or linkage with the risk of sarcoidosis. Though published results are conflicting, there seems to be suggestive evidence of a minor pro-inflammatory influence of the ACE D allele in sarcoidosis. At present, a more accurate interpretation of sACE levels in diagnosis and monitoring of sarcoidosis seems to be the main value of ACE I/D genotyping.

Endobronchial involvement and airway hyperreactivity in patients with sarcoidosis

STUDY OBJECTIVE

To determine the relationship between airway hyperreactivity (AHR) and endobronchial involvement in patients with sarcoidosis.

DESIGN

Prospective series of consecutive patients.

SETTING

Pulmonary clinic of a military, tertiary-care teaching hospital.

PATIENTS

Patients with newly diagnosed sarcoidosis.

INTERVENTIONS

All patients undergoing bronchoscopy for the diagnosis of sarcoidosis underwent an evaluation that included history, physical examination, chest radiography, and spirometry. Bronchoprovocation testing was done using methacholine. During bronchoscopy, six endobronchial biopsy (EBB) specimens were obtained. In patients with abnormal-appearing airways, four specimens were obtained from abnormal areas and two specimens were obtained from the main carina. In patients with normal-appearing airways, four specimens were obtained from a secondary carina and two specimens were obtained from the main carina. A biopsy specimen was considered positive if it demonstrated nonnecrotizing granulomas with special stains that were negative for fungal and mycobacterial organisms. Only patients with histologic confirmation of sarcoidosis were included in the data analysis.

MEASUREMENTS AND RESULTS

The study cohort included 42 patients (57.1% were men, 61.9% were African American, and mean age [+/- SD] was 37.3 +/- 6.6 years). AHR was present in nine patients (21.4%), while EBB revealed nonnecrotizing granulomas in 57.1% of patients. All patients with AHR had positive EBB findings compared to 45.5% of individuals without AHR (p = 0.005). There was a trend toward lower lung volumes and flow rates in patients with AHR, but this did not reach statistical significance. The mean serum angiotensin-converting enzyme level was higher in patients with AHR (79.3 +/- 53.9 IU/L vs 37.5 +/- 26.7 IU/L, p = 0.05). No other clinical variable correlated with the presence of AHR.

CONCLUSIONS

AHR may be seen in patients with sarcoidosis. Endobronchial involvement significantly increases the risk for AHR and may play a role in the development of AHR in patients with sarcoidosis. Other clinical factors are not clearly associated with AHR in patients with sarcoidosis.

Ace gene I/D polymorphism and sarcoidosis pulmonary disease severity

Previous studies of the insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE) gene in sarcoidosis have revealed both ethnic heterogeneity of I/D frequencies and controversy surrounding the association between the polymorphism and severity of disease. The objective of this study was, therefore, to clarify the role of the ACE I/D polymorphism in (1) disease susceptibility, (2) pulmonary disease severity (with particular reference to pulmonary fibrosis), and (3) pulmonary disease progression, in two distinct European sarcoidosis populations. Standard chest radiographic staging was performed on 118 UK and 56 Czech white patients with sarcoidosis at 2 yr from presentation. Pulmonary function data were analyzed, and patients were then categorized according to disease severity. A PCR-SSP assay was used to determine the ACE I/D genotype of each patient studied. The I/D allele frequencies from these patients were compared with frequencies from ethnically matched UK (n = 386) and Czech (n = 179) control subjects using a chi-square contingency table. No significant differences were seen in the distribution of the ACE I/D genotypes, allele frequencies or phenotype frequencies. Furthermore, no association was found between the ACE I/D polymorphism and pulmonary disease severity, fibrosis, and progression. We conclude that the ACE I/D polymorphism has no role in sarcoidosis susceptibility in European whites and that it is not a regulatory variant in this disease.

Non-asthmatic respiratory symptomatology

Because of the common nature of asthma and the attention this disease has been given in recent years, it is important to consider the possibility of other disorders that may present in a similar manner to asthma. Failure to consider alternative diagnoses often leads to inappropriate treatment with medications such as systemic corticosteroids that result in untoward morbidity. This review will discuss several diseases originating not only in the tracheobronchial tree but also in extrapulmonary sites, such as the gastrointestinal tract, that may be mistakenly diagnosed as asthma. Newly described entities such as irritant vocal cord dysfunction and exercise-induced hyperventilation syndrome are discussed in this article, as is new information pertaining to well-established diseases such as Churg-Strauss syndrome and sarcoidosis.