Hypersensitivity Pneumonitis Serology

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Hypersensitivity Pneumonitis Serology

Synonym/acronym: Farmer’s lung disease serology, extrinsic allergic alveolitis.

Common use

To assist in identification of pneumonia related to inhaled allergens containing Aspergillus or actinomycetes (dust, mold, or chronic exposure to moist organic materials).


Serum (2 mL) collected in a red-top tube. Place separated serum into a standard transport tube within 2 hr of collection.

Normal findings

(Method: Immunodiffusion) Negative.


Hypersensitivity pneumonitis is a respiratory disease caused by the inhalation of organisms from an organic source. Affected and symptomatic individuals demonstrate acute bronchospastic reaction 4 to 6 hr after exposure to the offending antigen. Inhalation of the antigen stimulates the production of immunoglobulin (Ig) G antibodies. The combination of immune complexing and cell-mediated immunopathogenesis results in a chronic granulomatous pneumonitis of the interstitial space of the lung. Hypersensitivity pneumonitis serology includes detection of antibodies to Aspergillus fumigatus, Saccharopolyspora rectivirgula, (formerly Micropolyspora faeni), Thermoactinomyces vulgaris, T. sacchari, and T. candidus. A negative test result does not rule out hypersensitivity pneumonitis as a possible diagnosis, nor does a positive test result confirm the diagnosis. Also, individuals with a positive test result may not exhibit the typical symptoms, and patients with severe symptoms may not have detectable levels of antibody while their disease is inactive. To confirm the diagnosis, it is necessary to obtain a sputum culture and chest x-rays.

This procedure is contraindicated for



  • Assist in establishing a diagnosis of hypersensitivity pneumonitis in patients experiencing fever, chills, and dyspnea after repeated exposure to moist organic sources

Potential diagnosis

Increased in

  • Hypersensitivity pneumonitis

Critical findings


Interfering factors


Nursing Implications and Procedure


  • Positively identify the patient using at least two unique identifiers before providing care, treatment, or services.
  • Patient Teaching:  Inform the patient this test can assist in diagnosing pneumonitis.
  • Obtain a history of the patient’s complaints, including a list of known allergens, especially allergies or sensitivities to latex.
  • Obtain a history of the patient’s immune and respiratory systems, symptoms, and results of previously performed laboratory tests and diagnostic and surgical procedures.
  • Obtain a list of the patient’s current medications, including herbs, nutritional supplements, and nutraceuticals (see Effects of Natural Products on Laboratory Values).
  • Review the procedure with the patient. Inform the patient that specimen collection takes approximately 5 to 10 min. Address concerns about pain and explain that there may be some discomfort during the venipuncture.
  • Sensitivity to social and cultural issues,  as well as concern for modesty, is important in providing psychological support before, during, and after the procedure.
  • Note that there are no food, fluid, or medication restrictions unless by medical direction.


  • Potential complications: N/A
  • Avoid the use of equipment containing latex if the patient has a history of allergic reaction to latex.
  • Instruct the patient to cooperate fully and to follow directions. Direct the patient to breathe normally and to avoid unnecessary movement.
  • Observe standard precautions, and follow the general guidelines in Patient Preparation and Specimen Collection. Positively identify the patient, and label the appropriate specimen container with the corresponding patient demographics, initials of the person collecting the specimen, date, and time of collection. Perform a venipuncture.
  • Remove the needle and apply direct pressure with dry gauze to stop bleeding. Observe/assess venipuncture site for bleeding or hematoma formation and secure gauze with adhesive bandage.
  • Promptly transport the specimen to the laboratory for processing and analysis.


  • Inform the patient that a report of the results will be made available to the requesting health-care provider (HCP), who will discuss the results with the patient.
  • Nutritional Considerations: Positive test results may be associated with respiratory disease. Malnutrition is commonly seen in patients with severe respiratory disease for reasons including fatigue and lack of appetite. The importance of following the prescribed diet should be stressed to the patient and/or caregiver.
  • Instruct the patient in preventive measures for protecting his or her lungs (e.g., avoid contact with persons who have respiratory or other infections; avoid use of tobacco; avoid highly polluted areas as well as work environments with hazards such as fumes, dust, and other respiratory pollutants).
  • Instruct the patient in deep breathing and pursed-lip breathing to enhance breathing patterns, as appropriate.
  • Inform the patient of smoking cessation programs, as appropriate.
  • Recognize anxiety related to test results, and be supportive of impaired activity related to lack of respiratory function, perceived loss of independence, and fear of shortened life expectancy. Discuss the implications of abnormal test results on the patient’s lifestyle. Provide teaching and information regarding the clinical implications of the test results, as appropriate. Educate the patient regarding access to counseling services. Provide contact information, if desired, for the American Lung Association (www.lungusa.org).
  • Reinforce information given by the patient’s HCP regarding further testing, treatment, or referral to another HCP. Answer any questions or address any concerns voiced by the patient or family.
  • Depending on the results of this procedure, additional testing may be performed to evaluate or monitor progression of the disease process and determine the need for a change in therapy. Evaluate test results in relation to the patient’s symptoms and other tests performed.

Related Monographs

  • Related tests include allergen-specific IgE, arterial/alveolar oxygen ratio, biopsy lung, blood gases, bronchoscopy, chest x-ray, CBC, culture (fungal, sputum), cytology sputum, eosinophil count, PFT, and pulse oximetry.
  • Refer to the Immune and Respiratory systems tables at the end of the book for related tests by body system.
Handbook of Laboratory and Diagnostic Tests, © 2013 Farlex and Partners