Incorporating Nasal Cytology Into Therapeutic Algorithms for CRSwNP: A Call for Precision Medicine

Dear Editor,

We read with great interest the recent article by Song et al, ¹ “Considerations for the use of biologics in chronic rhinosinusitis with nasal polyps,” published in Ear, Nose & Throat Journal. The authors provide a timely and comprehensive overview of biologic therapy in Cronic rhinosinusitis with nasal polyps (CRSwNP), highlighting key clinical considerations. However, we would like to underscore the absence of a simple, cost-effective, non-invasive, and repeatable diagnostic tool: nasal cytology.

Using a standardized nasal scraping technique, nasal cytology allows for the identification of key inflammatory cell types, neutrophils, eosinophils, mast cells, or mixed profiles, thereby enabling precise endotyping of local inflammation. Notably, local cellular patterns often diverge from systemic clinical or allergic findings. ² The method is well tolerated and can be repeated over time, even during active biologic treatment.

In a recent publication by our group, ³ we proposed a diagnostic-therapeutic algorithm for CRSwNP that integrates 3 core parameters: (1) nasal cytology via clinical-cytological grading (CCG), (2) the total nasal polyp score (TNPS) from endoscopy, and (3) the Sino-Nasal Outcome Test (SNOT)-22 questionnaire for assessing quality of life. This integrative model supports personalized therapeutic decisions. In particular, a CCG score ≥7—typically associated with eosinophil-mast cell infiltration and comorbidities such as asthma, allergy, or aspirin intolerance—indicates a high risk of relapse and may justify early initiation of biologics, even when TNPS is moderate.

Numerous studies have demonstrated that specific cytological patterns, especially eosinophil-mast cell infiltration, correlate with greater disease severity and predict recurrence after both medical and surgical treatment. ⁴ Unlike systemic biomarkers, nasal cytology directly captures the local mucosal inflammatory status, which is key for personalized therapy.

While biologics have undeniably improved management strategies for CRSwNP, their high cost and variable efficacy emphasize the need for accurate and individualized patient selection. Cytological assessment can help identify patients likely to benefit from biologics and those who may respond to optimized topical or surgical approaches. ⁵

Moreover, nasal cytology’s repeatability makes it an ideal monitoring tool throughout treatment. Shifts in cellular profiles can provide early signals of therapeutic response or relapse, thus enabling timely adjustments in clinical management. ⁶

As precision medicine continues to evolve in CRSwNP, tools like nasal cytology and CCG deserve to be included in treatment algorithms. We respectfully propose that future revisions of guidelines, such as European Position Paper on Rhinosinusitis and Nasal Polyps (EPOS) or Allergic Rhinitis and its Impact on Asthma (ARIA), explicitly incorporate nasal cytology as a practical, evidence-based tool to enhance patient stratification, guide therapy, and support cost-effective care.

Sincerely,

Matteo Gelardi, MD Former Associate Professor, Department of Otolaryngology, University of Foggia, Puglia, Italy