Clinical features and T-cell subsets in HIV-infected children with and without lymphocytic interstitial pneumonitis

Lymphocytic interstitial pneumonitis (LIP) is a non-infective lung condition common in untreated older children with vertically acquired HIV infection. Little is known about the prognosis in children with LIP, and diagnosis remains a problem where lung biopsy is not feasible. Our aim was to determine which clinical features aid the diagnosis of LIP in conjunction with the typical reticulonodular radiological picture, and whether the prognosis in children with LIP is different from that in HIV-infected children of the same age without LIP. We retrospectively compared the clinical features and T-cell subsets of 49 children with LIP with those of 56 children of similar age without LIP. Diagnosis of LIP was made radiologically. All children were apyrexial at the time of X-ray and acute intercurrent infections and tuberculosis had been excluded as far as possible. Ages ranged from 24 to 112 months in the non-LIP group and from 24 to 120 months in the LIP group. Digital clubbing and reticulo-endothelial hyperplasia were significantly more common in children with LIP than in those without. Children with LIP tended to have lower CD4+ counts and CD4% and higher CD8+ counts and CD8%, which resulted in significantly lower CD4/CD8 ratios in children under 5 years with LIP. It is possible in most cases to diagnose LIP using a combination of clinical and X-ray findings, as long as every effort is made to exclude tuberculosis. Lower CD4+ counts and CD4% as well as more frequent hospital admissions suggest that LIP adversely affects prognosis in children with HIV.