PPIB and mixed connective tissue disease: AAV: ANCA-associated vasculitis; ANA: Antinuclear antibodies; aPLs: Antiphospholipid antibodies; APS: Antiphospholipid syndrome; CEN-B: Anti centromere antibodies; CNS: Central nervous system; dcSSc: Diffuse cutaneous systemic sclerosis; lcSSc: Limited cutaneous systemic sclerosis; MCTD: Mixed connective tissue disorder; PBC: Primary biliary cholangitis; RF: Rheumatoid factor.