VTN and systemic lupus erythematosus: The EULAR/ACR classification criteria include positive ANA at least once as an obligatory criterion, followed by additive weighted criteria grouped in seven clinical (constitutional, hematological, neuropsychiatric, mucocutaneous, serosal, musculoskeletal, and renal) and three immunological domains [(aPL, SLE-specific antibodies (anti-dsDNA, or anti-Smith), low complement proteins].