Multi-site screening for Pneumocystis jirovecii in lung cancer: possible tumour tissue colonization

<p class="MsoNormal" style="margin-bottom:0cm;line-height:200%"><strong><span lang="EN-GB" style="font-size:12pt;line-height:200%;font-family:&#39;times new roman&#39; , serif">Objectives</span></strong><span lang="EN-GB" style="font-size:12pt;line-height:200%;font-family:&#39;times new roman&#39; , serif">:</span></p><p class="MsoNormal" style="margin-bottom:0cm;line-height:200%"><span lang="EN-GB" style="font-size:12pt;line-height:200%;font-family:&#39;times new roman&#39; , serif">Recent studies suggest that various tumour types can
be colonized by different microorganisms, but data on one unusual fungus – <em>Pneumocystis jirovecii –</em> remain scarce.
Lung cancer patients are considered one of the risk groups for its infection.
Since <em>P. jirovecii</em> tends to
distribute focally within the lungs, this study aimed to determine its ability
to concentrate in lung tumour tissue and to assess potential associations with
genotypes of infecting strains.</span></p><p class="MsoNormal" style="margin-bottom:0cm;line-height:200%"><strong><span lang="EN-GB" style="font-size:12pt;line-height:200%;font-family:&#39;times new roman&#39; , serif">Methods</span></strong><span lang="EN-GB" style="font-size:12pt;line-height:200%;font-family:&#39;times new roman&#39; , serif">:</span></p><p class="MsoNormal" style="margin-bottom:0cm;line-height:200%"><span lang="EN-GB" style="font-size:12pt;line-height:200%;font-family:&#39;times new roman&#39; , serif">Fragments of neoplastic tissue (NPL), normal adjacent
tissue (NAT) and respiratory secretions (RS) were collected from 70 patients
with histologically confirmed primary lung cancer. DNA was extracted and
analysed by nested-PCR targeting the mtLSU rRNA and CYB loci, followed by
genotyping.</span></p><p class="MsoNormal" style="margin-bottom:0cm;line-height:200%"><strong><span lang="EN-GB" style="font-size:12pt;line-height:200%;font-family:&#39;times new roman&#39; , serif">Results</span></strong><span lang="EN-GB" style="font-size:12pt;line-height:200%;font-family:&#39;times new roman&#39; , serif">:</span></p><p class="MsoNormal" style="margin-bottom:0cm;line-height:200%"><em><span lang="EN-GB" style="font-size:12pt;line-height:200%;font-family:&#39;times new roman&#39; , serif">Pneumocystis
jirovecii</span></em><span lang="EN-GB" style="font-size:12pt;line-height:200%;font-family:&#39;times new roman&#39; , serif"> was detected in
fourteen samples derived from 8/70 individuals (11.4%): two NPL, six NAT and
six RS. In two patients, <em>Pneumocystis</em>
was detected in all three specimen types; both were diagnosed with the same
histological malignancy grade (G3, p&#61;0.036). The genotype distribution varied
across sample types in most cases. </span></p><p class="MsoNormal" style="margin-bottom:0cm;line-height:200%"><strong><span lang="EN-GB" style="font-size:12pt;line-height:200%;font-family:&#39;times new roman&#39; , serif">Conclusions</span></strong><span lang="EN-GB" style="font-size:12pt;line-height:200%;font-family:&#39;times new roman&#39; , serif">:</span></p><p>

<br /></p><p class="MsoNormal" style="margin-bottom:0cm;line-height:200%"><span lang="EN-GB" style="font-size:12pt;line-height:200%;font-family:&#39;times new roman&#39; , serif">Although NPL does not appear to be the preferred site
for <em>Pneumocystis</em>, such settlement may
be linked to the stage of tumour advancement. The genotype variation between
specimen types suggests non-uniform respiratory tract colonization. </span></p>