Working problem 6-Idiopathic pulmonary fibrosis

Question 1

What is idiopathic pulmonary fibrosis?

Answer 1

A rare, chronic, idiopathic, life-threatening disease that manifests over several years and is characterised by scar tissue within the lungs and progressive dyspnoea.
The cause of IPF is not known. A possible theory is that an unidentified insult causes damage to the alveolar epithelium, endothelium, and basement membrane. Cigarette smoke, organic or metal dust, GORD, diabetes, and infection have each been associated with IPF; however, the exact inciting exposure or exposures remain unknown

Question 2

What is the pathophysiology of IPF?

Answer 2

Irrespective of the actual inciting risk factor, the resulting injury triggers a pro-inflammatory and pro-fibrotic response that includes an influx of macrophages, fibroblasts, and other inflammatory cells. For reasons that are unclear, there is dysregulation of the normal tissue repair process; fibroblastic and myofibroblastic activity persists, resulting in the formation of fibroblastic foci, which are a pathological hallmark of the disease, continued deposition of extracellular matrix (ECM) proteins, and progressive fibrosis.
The enhanced and dysregulated activity of fibroblasts and myofibroblasts in IPF results in alveolar destruction, infiltration of the interstitial space with fibrosis, and architectural distortion of the lung parenchyma. These pathological changes lead to the clinical hallmarks of the disease.

Question 3

What are the investigations undertaken in IPF?

Answer 3

• CXR - basilar, peripheral, bilateral, asymmetrical, reticular opacities
• High resolution CT - basilar- and subpleural-predominant areas of increased reticulation, honeycombing, and possible traction bronchiectasis
• Trans-bronchial biopsy or surgical lung biopsy – fibrosis of varying ages; areas of normal lung next to areas of honeycombing; areas of more active scar formation, including fibroblastic foci; interstitial inflammation typically mild to moderate and patchy

Question 4

What is the management of IPF?

Answer 4

• Acute exacerbation
o Admission
o High dose corticosteroids – prednilosone
• Patients not experiencing acute exacerbation
o Smoking cessation
o Pulmonary rehabilitation
o Oxygen
o Proton-pump inhibitor – if GORD as risk factor (pantoprazole, omeprazole)
o Lung transplant - For patients who experience progressive physiological deterioration despite optimal medical management, or have contraindications to pharmacological treatment, severe functional impairment, oxygen dependency, and/or a deteriorating course

Question 5

What is sarcoidosis?

Answer 5

Sarcoidosis is a chronic granulomatous disorder, characterised by accumulation of lymphocytes and macrophages in the lungs and other organs. Although lungs and lymph nodes are involved in >90% of patients, virtually any organ can be involved.

Question 6

How do you assess sarcoidosis ?

Answer 6

• Sarcoidosis is a diagnosis of exclusion of granulomatous lung diseases, including tuberculosis and histoplasmosis.
• Diagnosis is more common among females and non-smokers and in those with a family history of sarcoidosis. It is also more common in black people in the US and in people of Scandinavian origin.
• Pulmonary symptoms such as cough and dyspnoea predominate. Costochondritis may also occur, resulting in chest wall pain.
• Constitutional symptoms are common and include chronic fatigue, weight loss, and low-grade fever. Other symptoms include photophobia and skin lesions. Arthralgia, affecting the knees, ankles, elbows, and wrists, occurs in about one third of people with sarcoidosis.
• It is important to consider berylliosis, especially in people with a history of occupational exposure to beryllium in the nuclear and aerospace industries.
• Chest signs include wheezing/rhonchi due to airway involvement, mimicking asthma.
• Lymph nodes are enlarged and non-tender. Cervical, submandibular nodes are often involved. Rarely, lymphadenopathy is generalised

Question 7

What are the investigations used to detect sarcoidosis

Answer 7

• CXR - hilar and/or paratracheal adenopathy with upper lobe predominant, bilateral infiltrates; pleural effusions (rare) and egg shell calcifications (very rare) may be seen
• FBC - anaemia in 4%-20%; leukopenia in 40%
• Serum urea and creatinine – may be elevated
• Liver enzymes – elevated
• Serum calcium – hypercalciumaemia
• Pulmonary function test - restrictive or obstructive or mixed pattern
• ECG – conduction defects
• flexible bronchoscopy with transbronchial lung biopsy - non-caseating granulomas
• bronchoalveolar lavage (BAL) - BAL lymphocytosis, with CD4-to-CD8 ratio >3.5
• purified protein derivative of tuberculin (PPD) - negative

Question 8

What is the management for sarcoidosis?

Answer 8

•	pulmonary disease
o	Oral corticosteroid – prednilosone
o	Cytotoxics – methotrexate
o	Oxygen
o	Lung transplant