Evaluation of a novel immunotherapy for treatment of chronic rhinitis in cats.

The pathogenesis of chronic rhinitis in cats is poorly understood and consistently effective therapies are not currently available. Therefore, randomized clinical trials were conducted to evaluate a novel immunotherapy for treatment of chronic rhinitis in adult (n=12) and young cats (n=28). In addition, cytokine profiles in cats with chronic rhinitis were compared to those of healthy cats. Cats were treated with a potent stimulator of innate immunity (liposome-IL-2 DNA complexes) and the effects of treatment on clinical signs and immune function were assessed. In adult cats with chronic rhinitis, immunotherapy led to significant improvement in frequency of sneezing but not in other clinical signs when compared to the placebo group, whereas immunotherapy failed to improve clinical signs in younger cats. Analysis of cytokine expression in cats with rhinitis did not reveal evidence of a Th2 cytokine bias in cats with rhinitis. We conclude that chronic rhinitis in cats is not a Th2-biased disease and that immunotherapy may lead to clinical improvement in adult cats with the disease.