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

Lymphoid interstitial pneumonia 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's syndrome (see Autoimmune Disorders of Connective Tissue: Sjögren's Syndrome), Hashimoto's thyroiditis, rheumatoid arthritis, and systemic lupus erythematosus (lupus). Average age of affected adults is 54.

Symptoms

Children develop wheezing, cough, and difficulty breathing, 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

Doctors can sometimes hear crackles in the lungs using a stethoscope.

Diagnosis requires chest x-ray, computed tomography (CT), and pulmonary function tests. Pulmonary function tests usually show a decrease in the amount of air the lungs can hold. Doctors often do bronchoscopy (see Symptoms and Diagnosis of Lung Disorders: Bronchoscopy) and wash segments of the lung with a salt-water solution and then collect the washings (bronchoalveolar lavage) for testing. Children may have abnormalities in their blood proteins that can help establish the diagnosis. If not, and for all adults, lung biopsy is usually necessary.

Prognosis and Treatment

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, other immunosuppressants, or both, but the effectiveness of these drugs is unknown.

Last full review/revision March 2008 by Talmadge E. King, Jr., MD