Diagnostic work-up of a patient with suspected IPF

IPF: idiopathic pulmonary fibrosis; HRCT: high-resolution computed tomography; UIP: usual interstitial pneumonia; NSIP: nonspecific interstitial pnuemonitis; IPAF: interstitial pneumonia with autoimmune features; BAL: bronchoalveolar lavage; ILD: interstitial lung disease; IgE: immunoglobulin E.

* Specific work-up will be guided by clinical findings. In addition to the clinical examination, work-up may include IgE levels for specific environmental exposures, rheumatoid factor, anti-cyclic citrullinated peptide, antinuclear antibodies, extractable nuclear antigen antibodies (Sjögren antibodies, scleroderma antibodies, and lupus antibodies), aldolase, creatinine kinase, and antisynthetase/myositis antibodies.

¶ The diagnosis of IPF requires multidisciplinary discussion, including specialists from pulmonary, pathology, radiology, and sometimes rheumatology, to improve diagnostic accuracy.

Δ Radiographic features of IPF include peripheral, basilar-predominant reticulations, honeycomb changes, and/or traction bronchiectasis.

◊ Patients with organizing pneumonia will generally have an infectious differential; occasional patients with low suspicion for infection should proceed directly to biopsy.

§ Transbronchial lung biopsy is preferred for the diagnosis of malignant and granulomatous processes; other infectious and eosinophilic processes often may be diagnosed with BAL alone.

¥ Transbronchial cryobiopsy is recommended as an alternative to surgical lung biopsy only in centers with procedural and pathological expertise in this technique.

‡ Histopathologic features of UIP include patchy dense fibrosis with architectural distortion, supleural/paraseptal location, fibroblastic foci, and/or absence of findings suggestive of other interstitial lung diseases.