Morcos MB, et al. - In this investigation, researchers outlined the spectrum of clinical and immunologic characteristics of cocaine/levamisole-associated autoimmunity syndrome (CLAAS), identified demographic risk factors, and created new pathogenesis hypotheses. Between 2001 and 2015, CLAAS individuals (n = 50) were identified at the University of Washington Medical Center, Harborview Medical Center, and affiliated clinics in Seattle, Washington, USA. Using contingency and logistic regression analyses, demographic, clinical, and immunologic variables were gathered and correlated. Among cocaine users, sex and race were identified as important risk modifiers in the developing CLAAS. The development of cytoplasmic ANCA (C-ANCA) has been linked to increased mortality. In addition, the enriched presence of anti-MPO/anti-PR3 dual reactivity in CLAAS was confirmed, further supporting the diagnostic utility of this feature.