Dr Carol Langford lecturing at S Carolina Rheum Assn. 1) EGPA usually ANCA negative. 2) a +ANCA does not = a Dx of Vasculitis. 3) +ANCA has a predictive value=90% if renal dz present; but PPV down to 30-60% if only sinus & pulmonary dz present. https://t.co/RfIQEUliRb