PT  - JOURNAL ARTICLE
AU  - Renan Mauch
AU  - Paulo Cesar Alves
AU  - Carlos Emilio Levy
AU  - José Dirceu Ribeiro
AU  - Antonio Fernando Ribeiro
AU  - Niels Høiby
AU  - Marcos Tadeu Nolasco Da Silva
TI  - Lymphocyte responses to Mycobacterium tuberculosis and Mycobacterium bovis are similar between BCG-vaccinated patients with cystic fibrosis and healthy controls
AID  - 10.1183/13993003.congress-2020.684
DP  - 2020 Sep 07
TA  - European Respiratory Journal
PG  - 684
VI  - 56
IP  - suppl 64
4099  - http://erj.ersjournals.com/content/56/suppl_64/684.short
4100  - http://erj.ersjournals.com/content/56/suppl_64/684.full
SO  - Eur Respir J2020 Sep 07; 56
AB  - Background: The low rate of nontuberculous mycobacteria (NTM) among Brazilian patients with cystic fibrosis (CF) may be due to a cross-reactive Bacille Calmette-Guérin (BCG) vaccination. In the present pilot study, we aimed to compare the lymphocyte responses against Mycobacterium tuberculosis (Mtb) and M. bovis (BCG) in BCG-vaccinated CF patients and healthy controls.Methods: The lymphocyte response of CF patients (n=10) and healthy controls (n=10) was assessed in terms of lymphocyte proliferation index (LPI), using flow cytometry. Median rates of each cell subtype (CD4, CD8, CD19 and gamma-delta) were also determined (Fig 1).Results: Median LPIs (CF vs. controls) were 22.9% vs. 13.0% (p=0.481) and 23.1% vs. 17.6% (p=0.481), upon stimulation with Mtb and BCG, respectively. Both groups had a predominant CD4 response to Mtb (median rate = 82.5% vs. 79.7%; p=0.796) and BCG (LPI=84.3% vs. 83.0%; p=0.853), which were significantly higher than the CD8, CD19 and gamma-delta responses within both groups. CF patients tended to have a higher CD8 response upon stimulation with the phytohemagglutinin mitogen than healthy controls (median rate = 42.8% vs. 31.7%, p=0.075) (Fig 2).Conclusion: The responses of BCG-vaccinated CF patients to Mtb and BCG are at least similar to those of healthy individuals. These are probably memory responses elicited by the BCG vaccination, that can cross-react with nontuberculous mycobacteria (NTM) and may explain the low frequency of NTM lung infection in our CF center.FootnotesCite this article as: European Respiratory Journal 2020; 56: Suppl. 64, 684.This abstract was presented at the 2020 ERS International Congress, in session “Respiratory viruses in the "pre COVID-19" era”.This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).