Merck Manual

Please confirm that you are not located inside the Russian Federation

honeypot link

Lymphoid Interstitial Pneumonia

(Lymphoid Interstitial Pneumonitis)


Joyce Lee

, MD, MAS, University of Colorado Denver

Last full review/revision Jun 2021| Content last modified Jun 2021
Click here for the Professional Version

Lymphoid interstitial pneumonia is an uncommon lung disease in which mature lymphocytes (a type of white blood cell) accumulate in the air sacs of the lungs (alveoli).

  • People usually cough and have difficulty breathing.

  • Diagnosis requires chest x-ray, computed tomography, pulmonary function tests, and often bronchoscopy, biopsy, or both.

  • Treatment involves corticosteroids, immunosuppressants, or both.

Lymphoid interstitial pneumonia is a form of idiopathic interstitial pneumonia. It can occur in children, usually those infected with the human immunodeficiency virus (HIV). Lymphoid interstitial pneumonia can also occur in adults, often those with autoimmune disorders such as plasma cell disorders, Sjögren syndrome, Hashimoto thyroiditis, rheumatoid arthritis, and systemic lupus erythematosus (lupus). Women and girls are more commonly affected. Average age of affected adults is 54.

Symptoms of Lymphoid Interstitial Pneumonia

Children develop cough and decreased ability to exercise, and they may not grow and gain weight. Adults develop difficulty breathing and cough over months or, in some cases, years. Less common symptoms include weight loss, fever, joint pain, and night sweats.

Diagnosis of Lymphoid Interstitial Pneumonia

  • Chest computed tomography

Diagnosis requires chest x-ray, computed tomography (CT), and pulmonary function testing. Pulmonary function tests usually show a decrease in the amount of air the lungs can hold. Doctors often do bronchoscopy and wash segments of the lung with a salt-water solution and then collect the washings (bronchoalveolar lavage) for testing.

Blood tests may reveal abnormalities in their blood proteins that can help establish the diagnosis. This blood protein test is particularly useful in children and may be adequate to establish the diagnosis. If not, and for all adults, lung biopsy is usually necessary.

Treatment of Lymphoid Interstitial Pneumonia

  • Corticosteroids or cytotoxic drugs

The prognosis is difficult to predict. The disorder may resolve on its own or after treatment, or it may progress to lung fibrosis or lymphoma (a cancer). One half to two thirds of people are alive 5 years after diagnosis.

Treatment is with corticosteroids, cytotoxic drugs (such as azathioprine or cyclophosphamide), or both, but the effectiveness of these drugs is unknown.

NOTE: This is the Consumer Version. DOCTORS: Click here for the Professional Version
Click here for the Professional Version
Others also read

Test your knowledge

Goodpasture Syndrome
Goodpasture syndrome is an uncommon autoimmune disorder in which bleeding into the lungs and progressive kidney failure occur. People with the syndrome usually have difficulty breathing and cough up blood. Which of the following groups is most likely to developing Goodpasture syndrome?
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID

Also of Interest

Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID