Secretory IgA-mediated immune response in saliva and early detection of Pseudomonas aeruginosa in the lower airways of pediatric cystic fibrosis patients

Author(s)

Mauch, Renan Marrichi ^{[1, 2]} ; Rossi, Claudio Lucio ^[2] ; Nolasco da Silva, Marcos Tadeu ^[1] ; Aiello, Talita Bianchi ^[3] ; Ribeiro, Jose Dirceu ^[1] ; Ribeiro, Antonio Fernando ^[1] ; Hoiby, Niels ^{[4, 5]} ; Levy, Carlos Emilio ^[2]

Affiliation

^[1] Univ Estadual Campinas, Ctr Invest Pediat, Sch Med Sci, Rua Tessalia Vieira Camargo 126, BR-13083887 Campinas, SP - Brazil

^[2] Univ Estadual Campinas, Sch Med Sci, Dept Clin Pathol, Rua Vital Brasil 251, 2nd Floor, Cidade Univ, BR-13083888 Campinas, SP - Brazil

^[3] Ctr Med Campinas, Lab Microbiol, Rua Dr Edilberto Luis Pereira da Silva 929, BR-13083190 Campinas, SP - Brazil

^[4] Copenhagen Univ Hosp, Rigshosp, Clin Microbiol Dept, Juliane Maries Vej 22, DK-2100 Copenhagen - Denmark

^[5] Univ Copenhagen, Costerton Biofilm Ctr, Dept Int Hlth Immunol & Microbiol, Fac Hlth & Med Sci, Blegdamsvej 3B, 24-1, DK-2200 Copenhagen - Denmark

• Document type: Journal article
• Source: MEDICAL MICROBIOLOGY AND IMMUNOLOGY; v. 208, n. 2, p. 205-213, APR 2019.
• Web of Science Citations: 1

Abstract

Pseudomonas aeruginosa (Pa) detection in the paranasal sinuses may help to prevent or postpone bacterial aspiration to the lower airways (LAW) and chronic lung infection in cystic fibrosis (CF). We assessed the ability of an ELISA test for measurement of specific Pa secretory IgA (sIgA) in saliva (a potential marker of sinus colonization) to early detect changes in the Pa LAW status (indicated by microbiological sputum or cough swab culture and specific serum IgG levels) of 65 patients for threeyears, in different investigation scenarios. Increased sIgA levels were detected in saliva up to 22months before changes in culture/serology. Patients who remained Pa-positive had significantly increased sIgA levels than patients who remained Pa-negative, both at the baseline (39.6 U/mL vs. 19.2 U/mL; p=0.02) and at the end of the follow-up (119.4 U/mL vs. 25.2 U/mL; p<0.001). No association was found between sIgA levels in saliva and emergence or recurrence of Pa in the LAW. A positive median sIgA result in the first year of follow-up implied up to 12.5-fold increased risk of subsequent Pa exposure in the LAW. Our test detected early changes in the P. aeruginosa LAW status and risk of exposure to P. aeruginosa in the LAW with twoyears in advance. Comparison with sinus culture is needed to assess the test's ability to identify CF patients in need of a sinus approach for Pa investigation, which could provide opportunities of Pa eradication before its aspiration to the lungs. (AU)

• FAPESP's process: 14/00007-8 - Investigation of Pseudomonas aeruginosa respiratory infection in patients with cystic fibrosis in a reference center in Brazil: evaluation of the utility of four different diagnostic methods
• Grantee: Renan Marrichi Mauch
• Support Opportunities: Scholarships in Brazil - Doctorate