CDA and asthma: Altogether, our observations point to the possibility that the allergic respiratory mucosa supports local affinity maturation of IgE, which is consistent with the detection of activation-induced cytidine deaminase and switch circle transcripts in the target organ in patients with AR and asthma, as well as nasal polyposis.38, 42, 43 However, it is entirely possible that some IgE transcripts detected in nasal biopsy specimens could represent plasma cells that have undergone GC reactions in regional lymph nodes before migrating to the nasal mucosa.44