Lack of association of programmed cell death 1 gene (PDCD1) polymorphisms with susceptibility to chronic urticaria in patients with positive autologous serum skin test.

BACKGROUND Autoimmune mechanisms play an important role in the pathophysiology of chronic urticaria (CU), and the autologous serum skin test (ASST) helps to identify patients with autoreactive CU. One of the factors involved in autoreactive mechanisms is the cell surface receptor programmed death-1 which is encoded by the programmed cell death 1 gene (PDCD1). OBJECTIVE To investigate whether PDCD1 polymorphisms influence susceptibility to CU. METHODS We enrolled 93 ASST-positive patients with CU and a control group consisting of 105 healthy volunteers. In all individuals, PD1.3 (7146 A/G; rs 11568821) and PD1.5 (7785 C/T; rs 2227981) polymorphisms were analyzed. RESULTS No statistically significant differences were found between CU patients and controls for allele or genotype distribution. We also did not observe any association between PDCD1 genotypes and severity of urticaria or age of disease onset. CONCLUSIONS PD1.3 and PD1.5 polymorphisms were not proven to be implicated in susceptibility to ASST-positive CU in the Polish population. A more comprehensive analysis of the 2q33-2q37 genomic region might reveal whether variants of 1 or more of the genes in this region are involved in susceptibility to CU.