Recent advances in rheumatology indicate increased relevance of autoantibodies. In this regard, positive ANA are now required as entrance criterium for the first EULAR/ACR classification criteria of SLE. Importantly, ANA diagnostic with detection of isolated anti-dense fine speckled antibodies (DSF-70) need consideration since their unique detection has been identified to exclude largely an autoimmune disease. Thus, highly qualified ANA diagnostic preferably on Hep-2 cell lines is a prerequisite of reliable diagnostics.Recent recommendations for the management of antiphospholipid syndrome define high versus low risk seroprofiles which also guide primary and secondary prophylaxis. Importantly triple positive APS patients (positive for anticradiolipin, anti-ß2 GP I positive and carrying lupus anticoagulant) should be treated with vitamin K antagonists while direct oral anticoagulants have been shown to be inferior in terms of risk/benefit. Treatment of obstetric APS is mainly based on low dose aspirin and low molecular heparin. Notably, this treatment should be maintained for 6 weeks after delivery. Thus, serologic findings provide the basis for certain key clinical decisions and require their reliable detection.