Serum (1 → 3)-β-D-glucan measurement as an early indicator of Pneumocystis jirovecii pneumonia and evaluation of its prognostic value.
Pneumocystis jirovecii (carinii) pneumonia (PJP) is a major cause of disease in immunocompromised individuals. However, until recently no reliable and specific serological parameters for the diagnosis of PJP have been available. (1 → 3)-β-D-Glucan (BG) is a cell wall component of P. jirovecii and of various other fungi. Data from the past few years have pointed to serum measurement of BG as a promising new tool for the diagnosis of PJP. We therefore conducted a retrospective study on 50 patients with PJP and 50 immunocompromised control patients to evaluate the diagnostic performance of serum BG measurement. Our results show an excellent diagnostic performance with a sensitivity of 98.0% and a specificity of 94%. While the positive predictive value was only 64.7%, the negative predictive value was 99.8% and therefore a negative BG result almost rules out PJP. BG levels were already strongly elevated in an average of 5 days and up to 21 days before microbiological diagnosis demonstrating that the diagnosis could have been confirmed earlier. BG levels at diagnosis and maximum BG levels during follow-up did not correlate with the outcome of patients or with the P. jirovecii burden in the lung as detected by Real-Time PCR. Therefore, absolute BG levels seem to be of no prognostic value. Altogether, BG is a reliable parameter for the diagnosis of PJP and could be used as a preliminary test for patients at risk before a bronchoalveolar lavage is performed.
Held
J
J
Institute of Medical Microbiology and Hygiene, University of Freiburg, 79104 Freiburg, Germany. juergen.held@uniklinik-freiburg.de
Koch
M S
MS
Reischl
U
U
Danner
T
T
Serr
A
A
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011020:Pneumonia, Pneumocystis / Q000175:diagnosis*; D011237:Predictive Value of Tests; D011379:Prognosis; D011509:Proteoglycans; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D044967:Serum / Q000737:chemistry*; D013997:Time Factors; D055815:Young Adult; D047071:beta-Glucans / Q000097:blood*
D015415:Biomarkers; D011509:Proteoglycans; D047071:beta-Glucans; C010770:polysaccharide-K