Chronic Rhinosinusitis: T2r38 Genotyping and Nasal Cytology in Primary Ciliary Dyskinesia

Objectives: Chronic rhinosinusitis (CRS) is a major hallmark of primary ciliary dyskinesia (PCD). We investigated the possible correlation between some severity markers of CRS and several clinical features of the disease. We further studied the bitter taste receptor TAS2R38 polymorphisms to identify the genotypes associated with more severe disease. Methods: We included 39 adult PCD patients with (CRSwNP) and without nasal polyposis (CRSsNP); a sample for nasal cytology was obtained and clinical cytological grading (CCG) was determined. The SNOT-22 and Lund-Mackay scores were recorded. A sample of DNA was extracted from peripheral blood to investigate TAS2R38 polymorphisms. Results: CRSwNP patients had features of more severe disease: indeed, they had statistically significantly higher frequency of previous sinus surgery, higher SNOT-22, LM scores, and CCG than CRSsNP patients. Upon genotyping of TAS2R38 polymorphisms, we observed that the AVI–AVI genotype, associated to homozygous nonfunctional bitter TAS2R38 receptor, was more prevalent among CRSwNP (100%) than in CRSsNP patients (0%); furthermore, AVI–AVI subjects showed statistically significantly worse SNOT-22 and CCG scores than PAV–PAV and PAV–AVI subjects. The group of AVI–AVI patients also had more frequent respiratory exacerbations, Gram-negative infections, and Pseudomonas aeruginosa colonization than PAV–PAV and PAV–AVI patients. Conclusion: Our findings indicate for the first time that PCD patients with CRSwNP display a more severe disease than those with CRSsNP. Genotyping of TAS2R38 polymorphisms demonstrated that in PCD patients, the AVI–AVI genotype is strikingly more prevalent among CRSwNP than in CRSsNP, while the PAV–PAV genotype might be protective against Gram-negative infections and respiratory exacerbations. Level of Evidence: 3 Laryngoscope, 133:248–254, 2023