Pitfalls in Serological Diagnosis of Cryptococcus gattii Infections.
The detection of cryptococcal antigen by latex agglutination tests (LATs), enzyme-linked immunoassays (ELISA), or lateral flow assay (LFA) is an important tool for diagnosis of a Cryptococcus infection. Cerebrospinal fluid and/or serum samples of 10 patients with cryptococcosis due to Cryptococcus gattii or a hybrid of Cryptococcus neoformans and C. gattii were examined by three LATs (the IMMY Latex-Crypto(®) test, the Pastorex(TM) Crypto Plus, and the Remel Cryptococcus Antigen Test Kit) and the LFA made by Immuno-Mycologics. LATs based on monoclonal antibodies (mAbs) like the Pastorex(TM) Crypto Plus or the Remel Cryptococcus Antigen Test Kit turned out to have an insufficient sensitivity to detect four out of 10 C. gattii infections, including one infection by a hybrid between C. gattii and C. neoformans. Reflecting the ongoing expansion of C. gattii in geographical zones outside of tropical and subtropical areas like Mediterranean countries, Vancouver Island (British Columbia, Canada) and the Pacific Northwest region (USA), these findings are alarming because of the risk of delayed diagnosis of infections caused by C. gattii. Therefore, the preliminary serological screening for cryptococcal antigen in the case of a suspected Cryptococcus infection should be performed by using an assay with a broad range specificity and sensitivity for C. neoformans and C. gattii, including their hybrids.
Division of Mycology, Robert Koch Institute, Berlin, Germany tintelnotk@rki.de.
Kathrin
K
Tintelnot
Department of Medical Microbiology and Infectious Diseases, Canisius-Wilhelmina Hospital, Nijmegen, The Netherlands.
Ferry
F
Hagen
Division of Mycology, Robert Koch Institute, Berlin, Germany.
Chang Ok
CO
Han
Division of Mycology, Robert Koch Institute, Berlin, Germany.
Michael
M
Seibold
Division of Mycology, Robert Koch Institute, Berlin, Germany.
Volker
V
Rickerts
CBS-KNAW Fungal Biodiversity Centre, Utrecht, The Netherlands.
Teun
T
Boekhout
D000328:Adult; D000368:Aged; D000818:Animals; D000946:Antigens, Fungal / Q000652:urine*; D001955:British Columbia; D002846:Chromatography, Affinity / Q000379:methods; D003453:Cryptococcosis / Q000175:diagnosis*; D056285:Cryptococcus gattii / Q000276:immunology*; D003455:Cryptococcus neoformans / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D006801:Humans; D007841:Latex Fixation Tests / Q000379:methods; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D012698:Serologic Tests / Q000379:methods*; D014481:United States
D000946:Antigens, Fungal
Cryptococcus gattii; antigen detection; cryptococcosis; disseminated infection; false negative; monoclonal antibodies; polyclonal antibodies