Protein Tyrosine Phosphatase-Like Protein Ia2 Antibodies and Glutamic Acid Decarboxylase 65 Antibodies (GADA) are not Associated With Sarcoidosis

Abstract

The existence of an association between glu-tamic acid decarboxylase 65 antibodies (GADA) and/or IA2 antibodies and sarcoidosis was evaluated. Materials and Methods: 78 patients with docu-mented sarcoidosis, divided according to the presence (N=37) or absence (N=41) of autoim-mune manifestations were evaluated for GADA and IA2 antibodies using, a radioligand assay with human recombinant 35S-labeled GAD65 and IA2 respectively. Results: Two patients with GADA (2.6%) and one (1.3%) with IA2ab, both in the group of pa-tients with autoimmunity associated sarcoidosis were found. The GADA positive patient had manifest Type 1 diabetes that succeeded sarcoi-dosis. IA2 ab-positivity was seen among patients with isolated sarcoidosis. GADA and IA2ab fre-quencies were not increased compared to refer-ence subjects (2-3%). Conclusions: No clear association between sar-coidosis and GADA and/or IA2ab was found. In patients with sarcoidosis, GADA seem to be as-sociated with type 1 diabetes or other autoim-mune manifestations rather than with sarcoido-sis per se.