Persistence of trophozoites after successful treatment of Pneumocystis carinii pneumonia
el-Sadr, W.; Sidhu, G.
Annals of Internal Medicine 105(6): 889-890
1986
ISSN/ISBN: 0003-4819 PMID: 3490813 Document Number: 273738
A case of a patient with AIDS and P. carinii pneumonia is reported who showed a prompt clinical response to treatment with 3 ampoules of trimethoprim sulphamethoxazole by iv injection every 6 h for 3 weeks. He developed pneumothorax and subsequently a bronchopleural fistula, which required thoracotomy after completion of treatment. At that time chest roentgenogram showed resolution of infiltrates and pathologic examination of lung biopsy showed an organizing pneumonia with acidophilic material typical of P. carinii pneumonia filling the alveoli. Gomori's methenamine-silver stain was negative for cysts; electron micrographs showed no cysts but many degenerate trophozoites which filled the alveolar lumina, suggesting that the trophozoites may be more resistant to chemotherapy than cysts. The degenerate appearance of the trophozoites indicates that in this patient they may not have been viable. The diagnosis of P. carinii pneumonia in AIDS patients is discussed. The authors report a case in which lung biopsy of a patient with Pneumocystis carinii pneumonia (PCP) showed persistence of multiple trophozoites at the end of co-trimoxazole therapy (trimethoprim-sulfamethoxazole). The trophozoites were degenerate in appearance ultrastructurally, suggesting that they may not have been viable. No cysts were demonstrated and it is suggested that trophozoites may have a greater potential for survival. It is not known what the clinical relevance of this finding is and how it relates to recurrence of infection.M. Ellis.