Increased frequency of the PTPN22W* variant in primary Sjogren's Syndrome: Association with low type I IFN scores

- PTPN22W* risk variant confers increased susceptibility for primary Sjogren's Syndrome development.
- PTPN22W* carriage associates with low type I IFN scores in peripheral blood.
- Our results support the concept of distinct genetic background and associated immune pathways among pSS subsets.

Recent data suggest the association of the autoimmune gene variant PTPN22W* with dampened type I Interferon (IFN) responses, seen in a subset of primary Sjogren's Syndrome (pSS) patients. We sought to explore the potential contribution of PTPN22W* in this setting. PTPN22W* was identified in DNA samples derived from 352 pSS patients and 482 healthy controls (HC). Type I IFN score was determined in available peripheral blood cDNA of 164 pSS patients by Real-Time PCR. Increased prevalence of the PTPN22W* variant was detected in pSS patients compared to HC [9.7% vs 5.0%, p-value: 0.02]. Of interest, only the low but not the high type I IFN pSS subgroup displayed higher PTPN22W* rates compared to HC (12.2% vs 5.0%, p-value: 0.03). PTPN22W* risk variant increases susceptibility for pSS, particularly the low type I IFN subset implying the presence of distinct genetic backgrounds among low and high type I IFN autoimmune subgroups.