D3.221 - Cat Immunotherapy and Real-Life Data: A Single-Center Experience

With the increasing rate of cat ownership, cat sensitization is becoming more common. Because of continuous indoor exposure, cat allergen is one of the leading triggers of allergic rhinitis and/or asthma and may markedly impair daily functioning and quality of life. Allergen-specific immunotherapy (AIT) is a causal treatment approach aimed at modifying the natural course of disease by reducing symptom burden and medication requirements.

Objective: To evaluate the real-life effects of allergen-specific immunotherapy on quality of life in patients receiving AIT for cat allergy, and to explore differences in treatment response according to the presence of asthma and the pattern of sensitization.

Nineteen adult patients who were diagnosed with allergic rhinitis with or without asthma, found to have cat allergy, and started on immunotherapy (Roxall clustoid) in the Immunology and Allergy outpatient clinic between 2024 and 2026 were included in the study. Demographic variables (age, sex, smoking status) and clinical/laboratory parameters (total IgE, eosinophil count and percentage, skin prick test and/or specific IgE results, treatment regimens, and AIT duration) were recorded from medical files. The Mini Rhinoconjunctivitis Quality of Life Questionnaire (Mini-RQLQ) and the Rhinitis Quality of Life Questionnaire short form (RQLQ-SF) were administered at baseline and at months 1, 3, 6, and 12.

Of the 19 patients included, 94.7% were female, and the mean age was 36.47 ± 11.00 years. Most patients were polysensitized (n=16, 84.2%). Seven patients (36.8%) had allergic rhinitis alone, whereas 12 (63.2%) had concomitant allergic rhinitis and asthma. The mean duration of cat sensitization was 22.00 ± 27.53 months. During follow-up, both Mini-RQLQ and RQLQ-SF scores showed a declining trend from the first month onward. The mean Mini-RQLQ score decreased from 3.30 at baseline to 1.03 at month 12, while the mean RQLQ-SF total score decreased from 1.48 to 0.71. The reduction was more pronounced in patients without asthma; in this subgroup, the median Mini-RQLQ score decreased from 3.50 to 1.11, and the median RQLQ-SF score from 1.17 to 0.69. Similarly, in patients with concomitant allergic rhinitis and asthma, the median Mini-RQLQ score decreased from 3.64 to 0.79, and the median RQLQ-SF score from 1.72 to 0.45. Analysis of RQLQ-SF domains showed the most marked improvement in sleep-related and daily/practical activity-related domains. No significant adverse effects were observed apart from local reactions.

In real-life clinical practice, cat immunotherapy appears to be a safe treatment option and may lead to clinically meaningful improvement in quality of life in patients with cat allergen–related allergic rhinitis with or without asthma. However, given the small sample size, these findings should be considered preliminary. Larger, multicenter, controlled studies with long-term follow-up are needed.