title: Diagnosis of invasive candidiasis by enzyme-linked immunosorbent assay using the N-terminal fragment of Candida albicans hyphal wall protein 1.
abstract: BACKGROUND
  The diagnosis of invasive candidiasis is difficult because there are no specific clinical manifestations of the disease and colonization and infection are difficult to distinguish. In the last decade, much effort has been made to develop reliable tests for rapid diagnosis of invasive candidiasis, but none of them have found widespread clinical use.
  
  
  RESULTS
  Antibodies against a recombinant N-terminal fragment of the Candida albicans germ tube-specific antigen hyphal wall protein 1 (Hwp1) generated in Escherichia coli were detected by both immunoblotting and ELISA tests in a group of 36 hematological or Intensive Care Unit patients with invasive candidiasis and in a group of 45 control patients at high risk for the mycosis who did not have clinical or microbiological data to document invasive candidiasis. Results were compared with an immunofluorescence test to detect antibodies to C. albicans germ tubes (CAGT). The sensitivity, specificity, positive and negative predictive values of a diagnostic test based on the detection of antibodies against the N-terminal fragment of Hwp1 by immunoblotting were 27.8 %, 95.6 %, 83.3 % and 62.3 %, respectively. Detection of antibodies to the N-terminal fragment of Hwp1 by ELISA increased the sensitivity (88.9 %) and the negative predictive value (90.2 %) but slightly decreased the specificity (82.6 %) and positive predictive values (80 %). The kinetics of antibody response to the N-terminal fragment of Hwp1 by ELISA was very similar to that observed by detecting antibodies to CAGT.
  
  
  CONCLUSIONS
  An ELISA test to detect antibodies against a recombinant N-terminal fragment of the C. albicans germ tube cell wall antigen Hwp1 allows the diagnosis of invasive candidiasis with similar results to those obtained by detecting antibodies to CAGT but without the need of treating the sera to adsorb the antibodies against the cell wall surface of the blastospore.
authors: Departamento de Inmunología, Microbiología y Parasitología, Facultad de Medicina y Odontología, Universidad del País Vasco, Bilbao, Vizcaya, Spain. oiblatoa@lg.ehu.es <oiblatoa@lg.ehu.es>
authors: Ana
authors: A
authors: Laín
authors: Natalia
authors: N
authors: Elguezabal
authors: Sonia
authors: S
authors: Brena
authors: Juan Carlos
authors: JC
authors: García-Ruiz
authors: Amalia
authors: A
authors: Del Palacio
authors: María D
authors: MD
authors: Moragues
authors: José
authors: J
authors: Pontón
mesh_terms: D000595:Amino Acid Sequence; D000908:Antibodies, Fungal / Q000276:immunology* / Q000302:isolation & purification; D000946:Antigens, Fungal / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification; D002176:Candida albicans / Q000737:chemistry* / Q000276:immunology; D002177:Candidiasis / Q000175:diagnosis* / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005656:Fungal Proteins / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification*; D006801:Humans; D015151:Immunoblotting / Q000379:methods; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification*; D008969:Molecular Sequence Data; D016415:Sequence Alignment
chemical_list: D000908:Antibodies, Fungal; D000946:Antigens, Fungal; D005656:Fungal Proteins; C118102:HWP1 protein, Candida albicans; D008562:Membrane Glycoproteins