Update in Interstitial Lung Disease 2014

Rapamycin nanoparticles improves drug bioavailability in PLAM treatment by interstitial injection

BACKGROUND

Pulmonary lymphangiomyomatosis (PLAM) is a rare interstitial lung disease characterized by diffuse cystic changes caused by the destructive proliferation of smooth muscle-like cells or LAM cells. PLAM is more common in young women than other people, and a consensus is lacking regarding PLAM treatment. The clinical treatment of PLAM is currently dominated by rapamycin. By inhibiting the mTOR signaling pathway, rapamycin can inhibit and delay PLAM's occurrence and development. However, the application of rapamycin also has shortcomings, including the drug's low oral bioavailability and a high binding rate to hemoglobin, thus significantly decreasing the amount of drug distributed to the lungs.

METHODS AND RESULTS

Here, we developed a new mode of rapamycin administration in which the drug was injected into the intrathecal space after being nanosized; the directional flow characteristics of the liquid in the intrathecal space were exploited to increase the drug content in the interstitial fluid to the greatest extent possible. We studied the rapamycin content in the interstitial fluid and blood after intervaginal space injection (ISI). Compared with oral administration, ISI significantly increased the drug concentration in the lung interstitial fluid.

CONCLUSIONS

These results provided new ideas for treating PLAM and optimizing the dosing regimens of drugs with similar characteristics to rapamycin.

Humidifier Disinfectant Consumption and Humidifier Disinfectant-Associated Lung Injury in South Korea: A Nationwide Population-Based Study

Humidifier disinfectant (HD) is a household biocidal product used in humidifier water tanks to prevent the growth of microorganisms. In 2011, a series of lung injury cases of unknown causes emerged in children and pregnant women who had used HD in Korea. This study investigated changes in the nationwide number of cases of humidifier disinfectant-associated lung injury (HDLI) in concordance with nationwide HD consumption using data covering the entire Korean population. More than 25 kinds of HD products were sold between 1994 and 2011. The number of diagnosed HDLI, assessed by S27.3 (other injuries of lungs) of the Korea National Health Insurance Service (NHIS) data, sharply increased by 2005, subsequently decreased after 2005, and almost disappeared after 2011 in concordance with the annual number of HD sales. The number of self-reported HDLIs, assessed using data from all suspected HDLI cases registered in the Korea Ministry of Environment, changed with the annual number of HD sales, with a delay pattern, potentially induced by the late awareness of lung injury diseases. The present study suggests that changes in the nationwide annual consumption of HD products were consistent with changes in the annual number of HDLI cases in Korea.

Visual analogue scales for interstitial lung disease: a prospective validation study

BACKGROUND

Visual analogue scales (VAS) are simple symptom assessment tools which have not been validated in interstitial lung disease (ILD). Simple measures of ILD disease burden would be valuable for non-specialist clinicians monitoring disease away from ILD specialist centres.

OBJECTIVE

To validate VAS to assess change in dyspnoea, cough and fatigue in ILD, and to define the minimal clinically important difference (MCID) for change in these.

METHODS

Patients of 64 with ILD completed VAS for dyspnoea, cough and fatigue. Baseline King's Brief ILD questionnaire (K-BILD) scores, lung function and 6-min walk test results were collected. Tests were repeated 3-6 months later, in addition to a seven-point Likert scale. The MCID was estimated using median change in VAS in patients who reported 'small but just worthwhile change' in symptoms at follow-up. Methods were repeated in a validation cohort of 31 ILD patients to confirm findings.

RESULTS

VAS scores were significantly higher for patients who reported a 'small but just worthwhile change' in symptoms vs. 'no change' or 'not worthwhile change' (P < 0.01). The MCID for VAS Dyspnoea was estimated as 22.0 mm and 14.5 mm for VAS Fatigue. These results were reproducible in the validation cohort. Results were not significant for VAS Cough. Change in VAS Dyspnoea correlated with change in K-BILD (r = -0.51, P < 0.01), forced vital capacity (r = -0.32, P = 0.01) and 6-min walking distance (r = -0.37, P = 0.01).

CONCLUSION

The VAS is valid for assessing change in dyspnoea and fatigue in ILD. The MCID is estimated as 22.0 mm for dyspnoea and 14.5 mm for fatigue. This could be used to monitor disease in settings away from ILD specialist review.

MESH DESCRIPTORS

Lung Diseases, Interstitial, Dyspnoea, Fatigue, Cough.

Exertional dyspnoea in interstitial lung diseases: the clinical utility of cardiopulmonary exercise testing

Interstitial lung diseases (ILDs) represent a heterogeneous group of pathologies characterised by alveolar and interstitial damage, pulmonary inflammation (usually associated with fibrosis), decreased lung function and impaired gas exchange, which can be attributed to either a known or an unknown aetiology. Dyspnoea is one of the most common and disabling symptoms in patients with ILD, significantly impacting quality of life. The mechanisms causing dyspnoea are complex and not yet fully understood. However, it is recognised that dyspnoea occurs when there is an imbalance between the central respiratory efferent drive and the response of the respiratory musculature. The respiratory derangement observed in ILD patients at rest is even more evident during exercise. Pathophysiological mechanisms responsible for exertional dyspnoea and reduced exercise tolerance include altered respiratory mechanics, impaired gas exchange, cardiovascular abnormalities and peripheral muscle dysfunction.

This review describes the respiratory physiology of ILD, both at rest and during exercise, and aims to provide comprehensive and updated evidence on the clinical utility of the cardiopulmonary exercise test in the assessment and management of these pathological entities. In addition, the role of exercise training and pulmonary rehabilitation programmes in the ILD population is addressed.

Preoperative physiotherapy in subjects with idiopathic pulmonary fibrosis qualified for lung transplantation: implications on hospital length of stay and clinical outcomes

BACKGROUND

Lung transplantation (LTx) candidates with chronic disease are more prone to exercise limitations. Preoperative physiotherapy (PP) can improve exercise tolerance, which in some patients, is severely impaired, often leaving them housebound. The aim of this study was to answer this question: In patients with idiopathic pulmonary fibrosis (IPF) qualifying for LTx, is PP effective in improving postoperative outcomes and reducing length of stay (LOS) after transplantation?

METHODS

Six major databases were searched up to December 2015. We did not apply limits to publication date, date, gender, or language. Citations were accepted if they discussed preoperative physiotherapeutic treatment in patients with IPF waiting for LTx.

RESULTS

After the full texts were read, three papers met the inclusion criteria and were included. All of these papers had an observational design. In total, 55 subjects with IPF and awaiting LTx were observed.

CONCLUSIONS

The effectiveness of PP in improving postoperative outcomes and reducing LOS following LTx remains unclear, although it appears to benefit IPF patients who qualify for LTx by improving their health status, physical activity levels, and respiratory-related symptoms.