Evaluating Sinus Microbiology by Transplant Status in Persons With Cystic Fibrosis: A Matched Cohort Study

Objective. Sinus disease is prevalent in persons with cystic fibrosis (PwCF) and may be a reservoir of airway infection in postlung transplant (pTx) patients. The microbial composition of cystic fibrosis sinuses and its associations with chronic rhinosinusitis (CRS) is relatively unexplored. We aimed to examine the sinus and lower airway microbiome and their associations with CRS in PwCF and pTxPwCF. Study Design. Prospective single-centre study. Setting. A total of 31 sex and age (+/- 2 years) matched PwCF and pTxPwCF. Methods. Demographic and clinical data along with sinus swabs and sputum were collected. CRS was assessed using Sinonasal Outcome Test-22 (SNOT-22) (patient reported outcome) and Lund-McKay (computed tomography sinus) scores. Samples underwent MiSeq Illumina sequencing of the universal 16S ribosomal RNA gene. Results. A total of 31 PwCF (15 pTxPwCF) were included. Aggregate airways microbiome composition was dominated by Pseudomonas (46%), Haemophilus (14%), Staphylococcus (11%), Streptococcus (10%), and Fusobacterium (6%). alpha-diversity was significantly lower in post-Tx samples across both sputum and sinus samples (P = .005). beta-diversity was significantly different between sputum (P = .004), but not sinus (P = .75) samples by transplant status. While there was a trend in higher beta-diversity associated with lower SNOT-22 score at time of first visit, this did not reach significance (P = .05). Conclusion. Sinus and airway microbiomes differed in PwCF and pTxPwCF, but the prevalent organisms remained consistent. Elucidating the relationship of the microbiome with clinical status to better understand when to intervene accordingly is needed to optimize sinus disease management in PwCF.