Development of IgG antibodies to Exophiala dermatitidis is associated with inflammatory responses in patients with cystic fibrosis.
BACKGROUND
The clinical importance of airway colonisation by the fungus Exophiala dermatitidis in patients with cystic fibrosis (CF) is unclear. We have previously shown that E. dermatitidis frequently colonises the airways of patients with CF. The aims of the present study were to determine whether patients who are colonised by E. dermatitidis have detectable fungal antigens in the circulation, develop anti-fungal antibodies, and show signs of inflammation and impaired respiratory function.


METHODS
We collected sputum and serum samples consecutively from 98 sputum-producing patients with CF aged more than 12 years. The serum samples were subjected to bacterial and fungal culturing and analyses for fungal antigens and inflammatory factors.


RESULTS
E. dermatitidis was recovered from 17 (17%) patients, the same isolation rate as for Aspergillus fumigatus. There were no difference regarding the levels of β-glucan in the sera from E. dermatitidis culture-positive and culture-negative patients with CF. Serological analysis revealed significantly higher levels of IgG antibodies to E. dermatitidis cell wall fragments in the E. dermatitidis culture-positive patients. Patients with higher level of E. dermatitidis IgG antibodies were more often colonised with non-tuberculous Mycobacteria, and less often with Staphylococcus aureus. The increased levels of IgG antibodies directed against E. dermatitidis were positively associated with higher white blood cell counts, increased erythrocyte sedimentation rate, pancreatic insufficiency, intravenous antibiotic treatment, and they were negatively associated with respiratory function (FEV1 % predicted). Overall, 4/17 Exophiala-positive patients were diagnosed as having symptomatic infection with E. dermatitidis and were treated with broad-spectrum azoles.


CONCLUSIONS
E. dermatitidis triggers antibody production and may cause significant airway infection in patients with cystic fibrosis.
Department of Infectious Diseases, University of Gothenburg, Sweden; Sahlgrenska Academy, University of Gothenburg, Sweden. Electronic address: nahid.kondori@microbio.gu.se.
Nahid
N
Kondori
Department of Pediatrics, Queen Silvia Children's Hospital, University of Gothenburg, Sweden; Gothenburg CF Centre, University of Gothenburg, Sweden; Sahlgrenska Academy, University of Gothenburg, Sweden.
Anders
A
Lindblad
Department of Infectious Diseases, University of Gothenburg, Sweden; Sahlgrenska Academy, University of Gothenburg, Sweden.
Christina
C
Welinder-Olsson
Department of Infectious Diseases, University of Gothenburg, Sweden; Department of Hematology and Coagulation, University of Gothenburg, Sweden; Sahlgrenska Academy, University of Gothenburg, Sweden.
Christine
C
Wennerås
Department of Geriatrics, Respiratory Medicine and Allergology, University of Gothenburg, Sweden; Gothenburg CF Centre, University of Gothenburg, Sweden; Sahlgrenska Academy, University of Gothenburg, Sweden.
Marita
M
Gilljam
D000293:Adolescent; D000328:Adult; D000888:Antibodies, Anti-Idiotypic / Q000276:immunology*; D000908:Antibodies, Fungal / Q000276:immunology*; D000946:Antigens, Fungal / Q000097:blood / Q000276:immunology; D002648:Child; D003430:Cross-Sectional Studies; D003550:Cystic Fibrosis / Q000097:blood / Q000150:complications / Q000276:immunology*; D005093:Exophiala / Q000276:immunology* / Q000302:isolation & purification; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007124:Immunoenzyme Techniques; D007074:Immunoglobulin G / Q000276:immunology*; D007249:Inflammation / Q000276:immunology / Q000473:pathology; D008297:Male; D060446:Phaeohyphomycosis / Q000150:complications / Q000276:immunology* / Q000382:microbiology; D012189:Retrospective Studies; D013183:Sputum / Q000276:immunology / Q000382:microbiology; D055815:Young Adult
D000888:Antibodies, Anti-Idiotypic; D000908:Antibodies, Fungal; D000946:Antigens, Fungal; D007074:Immunoglobulin G
Cystic fibrosis; Exophiala; Fungal infection; IgG antibodies