Nested PCR in the diagnosis of Pneumocystis carinii pneumonia (PCP) in AIDS patients

: The studies were undertaken to evaluate the usefulness of a nested PCR assay in the diagnosis of Pneumocystis carinii pneumonia (PCP) in AIDS patients. To achieve the end, 51 excretions samples from the respiratory tract were collected from HIV-infected patients with respiratory symptoms, and examined for the presence of specific DNA. A portion of the mitochondrial large-subunit rRNA gene of Pneumocystis carinii was amplified with outer primers pair pAZ 102E, pAZ 102H and internal primers pAZ 102X, pAZ 102Y. Positive nested PCR results were obtained with 36 out of 51 examined samples. Some 52.8% of the positive results were obtained with samples collected from patients without clinical diagnosis of PCP. It was concluded, that the nested PCR method, being too sensitive, is not suitable for the routine diagnosis of PCP in AIDS patients.