MPO and Sjogren syndrome: KL-6, Krebs von den Lungen-6; SP-D, surfactant protein-D; ANA, anti-nuclear antibody; PR3-ANCA, proteinase 3-specific anti-neutrophil cytoplasmic antibody; MPO-ANCA, myeloperoxidase-anti-neutrophil cytoplasmic antibody; QFT, QuantiFERON; IgG, Immunoglobulin G; sIL-2R, soluble interleukin-2 receptor; SS-A, anti-Sjögren’s syndrome A; SS-B, anti-Sjögren’s syndrome B; CCP, anti-cyclic citrullinated peptide; ACE, angiotensin converting enzyme; TNF-α, tumor necrosis factor-α; IL-6, Interleukin-6.