Importance of tissue sampling, laboratory methods, and patient characteristics for detection of Pneumocystis in autopsied lungs of non-immunosuppressed individuals

Abstract

To understand the epidemiological significance of Pneumocystis detection in a lung tissue sample of non-immunosuppressed individuals, we examined sampling procedures, laboratory methodology, and patient characteristics of autopsy series reported in the literature. Number of tissue specimens, DNA-extraction procedures, age and underlying diagnosis highly influence yield and are critical to understand yield differences of Pneumocystis among reports of pulmonary colonization in immunocompetent individuals.

Fig. 1

Detection of P. jirovecii DNA in autopsy lungs from adults, using n-PCR from multiple lung samples obtained from the right upper lobe. Horizontal axis shows the number of 0.4 g lung samples analyzed. Vertical axis numbers represent individual adults. a Fifty-five adults dying in the community from violence, accident or suicide. b Nineteen adults dying in the community from an underlying medical cause (expanded from Ref. [2]). Positive image positive for Pneumocystis-DNA, Negative image Negative for Pneumocystis-DNA, NP New positive individuals that were detected after the analysis of the 1st, 2nd, 3rd, ...etc. lung sample. This shows that in adults from the general population dying in the community there were no new positives or changes in detection results after the analysis of seven samples