Lymphocytic interstitial pneumonitis (LIP) is a lung disorder, also known as lymphoid interstitial pneumonitis/pneumonia, which predominantly occurs in children with HIV. Its cause is still not clear, but is thought to be due to infection of the soft tissues (parenchyma) lining the lung, either by HIV itself or by another infection such as Epstein-Barr Virus (EBV). HIV-infected children who develop LIP are diagnosed as having AIDS.

Symptoms and diagnosis

LIP causes shortness of breath, rapid breathing (tachypnea) and cough which get gradually worse. These are often accompanied by swollen glands, enlarged liver and spleen (hepatosplenomegaly), and eye inflammation (uveitis). In severe cases LIP causes shortage of oxygen in the body, leading to problems such as clubbed fingers.

A chest X-ray will show that something is wrong but may not distinguish it from other problems. A bronchoscopy may be needed to confirm the diagnosis of LIP, rather than PCP or bacterial pneumonia.

In adults, LIP is hard to diagnose because the symptoms could have a number of causes, and because LIP is often accompanied by recurrent bacterial pneumonia which can mask a proper diagnosis.

Treatment

Steroids have been reported to lead to considerable improvement in LIP, but the symptoms tend to recur rapidly if the treatment is discontinued, so long-term use is necessary. Because it is possible that LIP is caused by HIV itself, AZT has been tried in its treatment, but with variable benefits.

References

Blanche S. Longitudinal study of 94 symptomatic infants with perinatally acquired human immunodeficiency virus infection. Am J Dis Child 144(11): 1210-1215, 1990.

Connor EM et al. Lymphoid interstitial pneumonitis. In Pizzo PA et al. (eds) Pediatric AIDS: The Challenge of HIV Infection in Infants, Children and Adolescents. Baltimore: Williams & Wilkins, 1991.

Lin RY et al. Lymphocytic interstitial pneumonia: radiologic manifestations and pathologic correlation. Radiology 170: 83-87, 1989.

Morris JC et al. Lymphocytic interstitial pneumonitis in patients at risk of acquired immunodeficiency syndrome. Chest 91: 63-67, 1987.

Oldham SAA et al. HIV associated lymphocytic interstitial pneumonia: radiologic manifestations and pathologic correlation. Journal of Pediatrics 108: 498-503, 1986.

Principi et al. Effect of zidovudine on HIV infected children with lymphocytic interstitial pneumonitis. AIDS 5(4): 468-469, 1991.

Resnick L et al. Detection of HTLV-III/LAV-specific IgG and antigen in broncho-alveolar lavage fluid from two patients with lymphocytic interstitial pneumonitis associated with AIDS-related complex. American Journal of Medicine 82: 553-556, 1987.