Table 2– Results of the diagnostic procedure according to the performance of the currently recommended standard diagnostic approach with immunofluorescence (IF) as first test
First testSecond testResults
IFPCRTotal subjectsDefinitive PCP (IF test positive)Possible PCPPCP excluded
PositivePositive71 (100)71 (100)00
NegativePositive18 (10.5)03 (16.6)15 (83.3)
Negative153 (89.5)01 (0.65)#152 (99.3)
  • Data are presented as n (%). PCP: Pneumocystitis pneumonia. #: PCP could not be formally ruled out in only one patient with rheumatoid arthritis and lung involvement. The treating physicians prescribed 3-week therapy against Pneumocystis jirovecii, but judged the acute lung disease as “more likely to be caused by autoimmune disease exacerbation rather than PCP” in the discharge letter. Retrospective reviewers unaware of the PCR result agreed with this interpretation.