Granulomatosis with Polyangiitis (GPA) is a systemic small sized vascular disease involving vasculitis, granuloma, and necrosis that most often targets the Ear, Nose and Throat (ENT) and/or Lungs and/or Kidneys, and it is classically associated with Anti-Neutrophil Cytoplasmic Antibody (ANCA) positivity. The initial presentations of GPA most often indicate ENT involvement, possibly lungs involvement, and occasionally kidneys involvement. Nowadays the GPA can be divided into two types include Limited GPA: (ENT± Lung) involvement and Systemic GPA: [(ENT± Lung) + Kidney] involvement. ANCA is positive in 90% of the cases with active systemic GPA whereas, it is positive in about 60% of the cases with limited GPA and mainly is C-ANCA/anti-PR3. We need to know that early diagnosis of GPA and subsequent rapid initiation of treatment; may completely cure the disease. Well-known Criteria have been presented for Classifying/Diagnosing Wegener's Granulomatosis or GPA that are: "The 1990 American College of Rheumatology (ACR) Classification Criteria for Wegener's Granulomatosis", "The 2007 European Medicine Agency Algorithm (EMA) Diagnostic Criteria for Systemic GPA", and "The ACR/European League Against Rheumatism (EULAR) Provisional 2017 Classification Criteria for GPA". But they are mainly for classifying GPA and none have sufficient sensitivity and specificity for early diagnosis. Whereas, here are two Criteria, which have been designed by the corresponding author of this article that are "The Iran Criteria for Early Diagnosis of GPA", and "The 2017 ACR/EMA Revised Criteria for Too Early Diagnosis of GPA". It is claimed that they are able to diagnose GPA in the first a few months and the first month of the disease, respectively.

GPA, ANCA, ACR Criteria, EMA Criteria, ACR/EULAR Criteria, Iran Criteria, ACR/EMA Criteria