D1.198 - Efficacy of Cat Allergen Immunotherapy: A Multicenter Prospective Study

Cat dander is a major aeroallergen associated with allergic rhinitis, conjunctivitis, and asthma. Although allergen avoidance is recommended as first-line management, it is often impractical and pharmacotherapy may provide insufficient symptom control. Allergen immunotherapy (AIT) is the only disease-modifying treatment option. This study evaluated the efficacy and safety of cat-specific AIT in cat-sensitized patients with uncontrolled allergic rhinitis and/or asthma despite optimal pharmacological treatment. Early outcomes at six months are presented.

This ongoing multicenter prospective study included patients with confirmed cat sensitization who initiated cat-specific AIT. Demographic characteristics, clinical features, skin prick test(SPT) results, and cat-specific IgE levels were recorded at baseline. Symptom scores, medication scores, combined symptom–medication scores, visual analogue scale(VAS) scores were evaluated at baseline and during follow-up.

A total of 26 patients were included; 80.8% were female, with a mean age of 33.3 ± 8.2 years. Asthma was present in 65.4% of participants. SPT was positive to cat allergen in 92.3% of patients, with a median cat-specific IgE level of 6.51 kU/L(0.5–100). All but two of the patients had cats at home. At six months of follow-up, significant reductions were observed in daily symptom scores, medication scores, and combined scores compared with baseline (all p <0.001). VAS scores for all nasal, ocular, and asthma-related symptoms demonstrated significant improvement at month 6(p <0.001). Median MiniRQLQ scores decreased significantly from baseline (31.3 ± 9.1) to month 6(17.0 ± 7.1; p <0.001). Among patients with asthma (n = 17), CARAT scores improved significantly from baseline to month 6 (14.7 ± 4.05 vs. 19.0 ± 6.4; p = 0.012). No systemic adverse reactions were observed during the study period; local reactions occurred in 38.5% of patients.

Early results from this ongoing multicenter prospective study demonstrate that cat-specific allergen immunotherapy is effective and well tolerated, leading to significant improvements in symptom control, medication use within the first six months of treatment. Longer-term follow-up at 12 months and beyond will provide more clinical and immunological evidence regarding the efficacy and safety of cat allergen immunotherapy.