Acquired Cold Urticaria vs. Autoinflammatory Diseases, Genetic and Clinical Profile and Differential Diagnosis: Study of a Cohort of Patients in a Tertiary Reference Centre.

ABSTRACT

Acquired cold urticaria (ACU) is characterized by the development of itchy wheals after cold exposure. Generalized urticarial skin rashes triggered by cold exposure characterize certain monogenic autoinflammatory diseases (AIDs). The objective of this study is to investigate the presence of variants in genes causing AIDs that present with cold-induced urticarial skin rashes in patients clinically diagnosed with ACU, in order to look for susceptibility factors for the disease. Fifty patients with primary ACU were studied. Germline and post-zygotic variants on the NLRP3, NLRP12, NLRC4 and PLCG2 genes were investigated using next-generation sequencing technology. Seven patients (14%) carried 8 heterozygous germline variants in the following genes NLRP3 (n = 1), NLRP12 (n = 3), NLRC4 (n = 1), PLCG2 (n = 3). No pathogenic or likely pathogenic variants were detected, and deep analyses of the sequences obtained did not identify any post-zygotic variant. In conclusion, ACU is not related to post-zygotic or germline pathogenic variants in the NLRP3, NLRP12, NLRC4 and PLCG2 genes.