title: Diagnosis of Pneumocystis pneumonia: evaluation of four serologic biomarkers.
abstract: The diagnosis of Pneumocystis pneumonia (PCP) relies on microscopic visualization of Pneumocystis jirovecii organisms or DNA detection in pulmonary specimens. This study aimed to assess the usefulness of (1-3)-β-d-glucan (BG), Krebs von den Lungen-6 antigen (KL-6), lactate dehydrogenase (LDH) and S-adenosyl methionine (SAM) as serologic biomarkers in the diagnosis of PCP. Serum levels of BG, KL-6, LDH and SAM were investigated in 145 Portuguese patients, 50 patients from the Netherlands, 25 Spanish patients and 40 Portuguese blood donors. Data on clinical presentation, chest imaging and gasometry tests were available. PCP cases were confirmed by microscopy and PCR techniques. A cost-effectiveness analysis was performed. BG was found to be the most reliable serologic biomarker for PCP diagnosis, followed by KL-6, LDH and SAM. The BG/KL-6 combination test was the most accurate serologic approach for PCP diagnosis, with 94.3% sensitivity and 89.6% specificity. Although less sensitive/specific than the reference standard classic methods based on bronchoalveolar lavage followed by microscopic or molecular detection of P. jirovecii organisms, the BG/KL-6 test may provide a less onerous procedure for PCP diagnosis, as it uses a minimally invasive and inexpensive specimen (blood), which may be also a major benefit for the patient's care. The BG/KL-6 combination test should be interpreted within the clinical context, and it may be used as a preliminary screening test in patients with primary suspicion of PCP, or as an alternative diagnostic procedure in patients with respiratory failure or in children, avoiding the associated risk of complications by the use of bronchoscopy.
authors: Unidade de Parasitologia Médica, Grupo de Protozoários Oportunistas/VIH e Outras Protozooses-CMDT, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Lisboa, Portugal. Electronic address: esteves@ihmt.unl.pt.
authors: F
authors: F
authors: Esteves
authors: Unidade de Parasitologia Médica, Grupo de Protozoários Oportunistas/VIH e Outras Protozooses-CMDT, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Lisboa, Portugal.
authors: S S
authors: SS
authors: Calé
authors: Centro Hospitalar de Lisboa Norte, Hospital de Santa Maria, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal.
authors: R
authors: R
authors: Badura
authors: Department of Infectious Diseases, Leiden University Medical Center, Leiden, The Netherlands.
authors: M G
authors: MG
authors: de Boer
authors: Centro Hospitalar de Lisboa Central, Hospital de Curry Cabral, Serviço de Doenças Infecciosas, Lisboa, Portugal.
authors: F
authors: F
authors: Maltez
authors: CIBER de Epidemiología y Salud Pública, Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Sevilla, Spain.
authors: E J
authors: EJ
authors: Calderón
authors: Department of Infectious Diseases, Leiden University Medical Center, Leiden, The Netherlands.
authors: T J
authors: TJ
authors: van der Reijden
authors: Unidad Médico-Quirúrgica de Enfermedades Respiratorias, Hospital Universitario Virgen del Rocío, Sevilla, Spain.
authors: E
authors: E
authors: Márquez-Martín
authors: Instituto de Saúde Ambiental, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal.
authors: F
authors: F
authors: Antunes
authors: Unidade de Parasitologia Médica, Grupo de Protozoários Oportunistas/VIH e Outras Protozooses-CMDT, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Lisboa, Portugal.
authors: O
authors: O
authors: Matos
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D003362:Cost-Benefit Analysis; D005260:Female; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000097:blood; D008297:Male; D008853:Microscopy; D008875:Middle Aged; D018396:Mucin-1 / Q000097:blood; D009426:Netherlands; D045363:Pneumocystis carinii; D011020:Pneumonia, Pneumocystis / Q000175:diagnosis*; D016133:Polymerase Chain Reaction; D011174:Portugal; D011509:Proteoglycans; D013902:Radiography, Thoracic; D012436:S-Adenosylmethionine / Q000097:blood; D012680:Sensitivity and Specificity; D012698:Serologic Tests / Q000379:methods*; D013030:Spain; D055815:Young Adult; D047071:beta-Glucans / Q000097:blood
chemical_list: D015415:Biomarkers; C060192:MUC1 protein, human; D018396:Mucin-1; D011509:Proteoglycans; D047071:beta-Glucans; C010770:polysaccharide-K; D012436:S-Adenosylmethionine; D007770:L-Lactate Dehydrogenase
keywords: Diagnosis; Pneumocystis jirovecii; immunocompromised patients; pneumonia; serologic biomarkers