Bronchoalveolar lavage in HIV infected patients with interstitial pneumonitis

The value of taking microbiological and cytological specimens by flexible bronchoscopy and bronchoalveolar lavage under local anaesthesia was assessed on 43 occasions in 35 HIV infected children, aged 3 months to 16 years, with interstitial pneumonitis. In acute interstitial pneumonitis (n = 22, 26 specimens from bronchoalveolar lavages) the microbiological yield was 73%, Pneumocystis carinii being the commonest infective agent (n = 14). P carinii pneumonia was found only in children with deficient antigen induced lymphocyte proliferative responses who had not been treated with long term prophylactic co-trimoxazole. In contrast, in 13 children with chronic interstitial pneumonitis that was consistent with a diagnosis of pulmonary lymphoid hyperplasia who underwent bronchoalveolar lavage on 17 occasions, there were two isolates of cytomegalovirus and one of adenovirus, but P carinii was not found. Ten of the 13 children had normal antigen induced lymphocyte proliferative responses. Useful cytological data were also gleaned from bronchoalveolar lavage specimens. Lymphocytosis was significantly higher in pulmonary lymphoid hyperplasia (36(SD 11)%) than in P carinii pneumonia (24(19)%) whereas the percentage of polymorphonuclear neutrophils was significantly lower (3(2)% compared with 12(13)%). Flexible bronchoscopy with bronchoalveolar lavage is safe even in young infants and should reduce the necessity for open lung biopsy in the management of HIV infected children with interstitial pneumonitis.