Diagnosis and management of interstitial lung disease

Translational Respiratory Medicine

Table 4 Clues for specific diagnoses from blood and urine testing

Laboratory test	Abnormal result	Suggested disorder
CBC	Microcytic anemia	Occult pulmonary hemorrhage
	Normocytic anemia	CTD, chronic disease
	Leukocytosis	Infection, hematologic malignancy
	Eosinophilia	Eosinophilic pneumonia, drug toxicity
	Thrombocytopenia	CTD, sarcoidosis
Calcium	Hypercalcemia	Sarcoidosis
Creatinine	↑	CTD, pulmonary-renal syndrome, sarcoidosis; amyloidosis
Liver function	↑ GGT, ALT, AST	Sarcoidosis, amyloidosis, CTD (polymyositis)
Urine	Abnormal sediment with RBC casts and/or dysmorphic RBCs	Vasculitis (CTD, PAG, GPS, MPA)
Muscle enzymes	↑Increased CK, aldolase	PM, DM-PM
Angiotensin Converting Enzyme (ACE)	↑	Sarcoidosis (non-specific; can be increased in other ILD)
Lymphocyte proliferation	Stimulated by beryllium	CBD
Serum antibodies	↓ Quantitative immunoglobulins	Immunodeficiency (CVID)
	↑ ANA, RF, anti-CCP	CTD, RA
	↑ C-ANCA	PAG
	↑ P-ANCA	CTD, vasculitis
	↑ anti-GBM	GPS
	Positive specific precipitin	Supportive of HP
	↑ anti-Jo-1 or other anti-synthetase autoantibodies	PM, DM-PM
	↑ SS-A, SS-B	Sjögren’s syndrome

CBD = chronic beryllium diseases; COP = cryptogenic organizing pneumonia; CTD = connective tissue disease; CVID = common variable immunodeficiency; DAH = diffuse alveolar hemorrhage; DM-PM = dermatopolymyositis; DIP = desquamative interstitial pneumonia; GPS = Goodpasture’s syndrome; HP = hypersensitivity pneumonitis; MPA = microscopic polyangiitis; PM = polymyositis; PAG = polyangiitis with granulomatosis; RA = rheumatoid arthritis;
Reprinted with permission from Interstitial Lung Disease: A Practical Approach. Meyer KC, Raghu G: Patient evaluation. Second Edition, New York: Springer; 2011:3–16.