Pneumocystis carinii pneumonia monitored by P. carinii shedding in sputum by the polymerase chain reaction.

This study investigated the efficacy of applying the polymerase chain reaction (PCR) technique to the monitoring of therapy to P. carinii pneumonia (PCP). The PCR method was sensitive enough to determine P. carinii shedding in sputum samples which was not detectable by Diff-Quik (International Reagent Corp., Kobe, Japan) stain. By PCR, P. carinii disappeared in sputa on days 8 to 15 after treatment. Clinical improvements correlated with the loss of detectable P. carinii. This study represents a potential usefulness of PCR to monitor P. carinii shedding in sputum during treatment.