TRIM21 and autoimmune disease: Specific laboratory tests were performed ruling out immunological and autoimmune disorders, including anti-nuclear antibody profile (autoantibodies against RNP/Sm, SS-A, Ro-52, SS-B, Scl-70, Jo-1, centromere B, dsDNA, histones, anti-mitochondrial M2 antibody), anti-smooth muscle, anti-liver-kidney microsomal antibodies, anti-platelets, anti-gastric parietal cell, anti-cardiolipin IgG and IgM, anti-neutrophilic cytoplasmic antibodies (ANCA), lupus anticoagulant, rheumatoid factor (RF), and Coombs test.