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Volume 45, Number 1 January 2010

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Letter From the Editor: What Is Your Interstitial Lung

Disease Intelligence Quotient?

A

nterstitial lung disease (ILD) is a general term that includes avariety of chronic lung disorders. When an individual has

LD, the lung is affected in 3 ways. First, the lung tissue isamaged in some known or unknown way. Second, the alveolaralls become inflamed, and third, the interstitium becomes

carred and stiff. Patients with different types of ILD may havehe same symptoms but their symptoms may vary in severity.heir chest radiographs may appear identical. The course of

hese diseases is unpredictable. Some of the diseases improveith medication if treated when inflammation occurs. Chancesf recovery or the disease getting worse depend on the cause andeverity of the disease when it was first diagnosed. Computedomography (CT) scanning has become a frontline test in theiagnosis of ILD and can often suggest a specific diagnosis withhigh degree of certainty when the CT findings are combinedith clinical history. Find out your ILD intelligence quotient by

nswering the following questions. Then, read the articles in thisssue to learn more about ILD. I thank Dr Kanne and all authorsho contributed to this issue. I know it will be a valuable re-

ource to anyone who deals with ILD in their practice.

1. What is the most prevalent type of idiopathic ILD?A. Usual interstitial pneumonitis (UIP)B. Nonspecific interstitial pneumonitis (NSIP)C. Acute interstitial pneumonitis (AIP)D. Desquamative interstitial pneumonitis (DIP)E. Cryptogenic organizing pneumonitis (COP)

2. What ILD affects only women of childbearing age?A. Langerhans cell histiocytosisB. LymphangioleiomyomatosisC. AsbestosisD. SilicosisE. Usual interstitial pneumonitis

3. Which of the following pulmonary tests is the mostinvasive?A. Pulmonary function tests (PFTs)B. High-resolution computerized tomography (HRCT)

scanC. Transbronchial biopsyD. Bronchoalveolar lavage

E. Video-assisted thoracoscopic surgery

037-198X/10/$-see front matter © 2010 Elsevier Inc. All rights reserved.oi:10.1053/j.ro.2009.07.001

4. Which of the following drugs used to treat usual inter-stitial pneumonitis is classified as an antioxidant drug?A. AcetylcysteineB. AzathioprineC. ColchicineD. CyclophosphamideE. Pirfenidone

5. What is the main symptom of idiopathic pulmonaryfibrosis?A. Productive coughB. Shortness of breathC. FeverD. Chest pain

6. Which of the following is a common radiologic featureof nonspecific interstitial pneumonitis (NSIP)?A. Subpleural sparingB. Upper lobe predominanceC. Asymmetry of findingsD. Unilateral distributionE. Extensive honeycombing

nswers1. A, Usual interstitial pneumonitis: Some of the known

causes of ILD include exposure to toxins or pollutants(eg, silica dust, asbestos fibers, hard metal dust, chem-ical fumes, and ammonia or chlorine gases), infections,radiation, drugs, and other medical conditions, such ascollagen vascular diseases.1 Interstitial lung diseaseswithout a known cause are considered a subset of inter-stitial lung disease and are grouped together under thelabel idiopathic interstitial lung disease. UIP is the mostprevalent type of idiopathic ILD. Although the idiopathicdiseases have certain features in common, each also hasunique characteristics.

2. B, Lymphangioleiomyomatosis: Lymphangioleiomyo-matosis (LAM) is a rare disorder in which muscle cellsinvade and eventually obstruct the airways and bloodand lymph vessels in the lung; further, it affects only

women of childbearing age.1

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2 J. Collins

3. E, Video-assisted thoracoscopic surgery: When less in-vasive tests do not yield a specific diagnosis, a thoracicsurgeon may perform video-assisted thoracoscopic sur-gery (VATS). In this procedure, an endoscope is in-serted through a small incision between the ribs, allow-ing the surgeon to view the lungs on a video monitor.Surgical instruments are then inserted through anotherincision, and the surgeon removes thumbnail-sized tis-sue samples from 2 or 3 sites in the lungs.1 Pulmonaryfunction tests are a noninvasive way to measure theamount of gases exchanged across the alveolar/capillarymembrane. Transbronchial biopsy is performed on anoutpatient using local anesthesia and involves bron-choscopy combined with removal of one or more tissuesamples the size of a pin. In bronchoalveolar lavage,saline is injected through a bronchoscope into a sectionof lung and then immediately suctioned out. The with-drawn solution contains alveolar cells.

4. A, Acetylcysteine: Oxidation is a natural process thatleads to cell and tissue damage. The process may play arole in the development of scarring in the lungs. Onetrial of the antioxidant acetylcysteine found moderateimprovements in lung function in people with idiopathicpulmonary fibrosis, though no significant changes wereseen in mortality rates.1 Corticosteroids (anti-inflamma-tory drugs) are the initial treatment of choice for ILDbut they help a minority of people with the disease andwhen they do help, the benefits are usually temporary.Azathioprine, normally used to prevent organ rejectionafter a transplant, and the anticancer drug cyclophos-phamide are cytotoxic drugs that may be used to treatILD. Colchicine and pirfenidone are antifibrotics thatare sometimes used to help reduce the development ofscar tissue. In clinical studies, they showed promise forslowing the progression of lung damage without sup-pressing the immune system, but real-world resultshave generally been disappointing.1

5. B, Shortness of breath: Shortness of breath is the mainsymptom of idiopathic pulmonary fibrosis. It is a symp-

tom of many types of lung disease and is therefore

nonspecific. It may first appear during exercise andprogress to the point where any exertion is impossible.Eventually, the patient may become short of breatheven at rest.2 Another common symptom associatedwith ILD is dry cough. Fever and chest pain can bepresent in the event of superimposed infection.

6. A, Subpleural sparing: NSIP was initially thought toinvolve primarily the lung periphery. However, subse-quent studies have shown NSIP to have a peripherallypredominant pattern in only 38%-74% of patients.3,4 Inthe experience of Kligerman et al, lower lobe peribron-chovascular predominance, with subpleural sparing, iscommon in NSIP.5 The distribution of NSIP is usuallysymmetric and bilateral. Unilateral findings are exceed-ingly rare in NSIP and should suggest an alternate di-agnosis.5 Ground-glass opacity is present in nearly allcases. The absence of ground-glass opacity in additionto extensive honeycombing helps eliminate the diagno-sis of NSIP.5

Jannette Collins, MD, MEd, FCCPEditor

eferences. Mayo Clinic Staff: Interstitial lung disease. Available at: http://www.mayoclinic.

com/print/interstitial-lung-disease/DS00592/Method�print&DS. Ac-cessed January 25, 2009

. American Lung Association: Interstitial lung disease and pulmonary fi-brosis. Available at: http://www.lungusa.org/site/apps/nlnet/content3.aspx?c�dvLUK9O0E&b�2060161&content_id�{4350F20F-98E4-403B-A33B-68B20A3C2FBA}&notoc�1&gclid�CPvU18fSpZkCFQMnGgodWA3oqQ. Accessed January 25, 2009

. MacDonald SL, Rubens MB, Hansell DM, et al: Nonspecific interstitialpneumonia and usual interstitial pneumonia: comparative appearancesat and diagnostic accuracy of thin-section CT. Radiology 221:600-605,2001

. Johkoh T, Muller NL, Colby TV, et al: Nonspecific interstitial pneumo-nia: correlation between thin-section CT findings and pathologic sub-groups in 55 patients. Radiology 225:199-204, 2002

. Kligerman SJ, Groshong S, Brown KK, et al: Nonspecific interstitialpneumonia: radiologic, clinical, and pathologic considerations. Radio-

graphics 29:73-87, 2009