To the Editor,
We read with interest the recent discussion of ANCA vasculitis.(1) We would however like to highlight a particular etiology that was omitted and deserves attention because it raises consequential implications regarding treatment.
Levamisole, an anthelminthic agent with immunomodulatory properties, is reported as an adulterant in the majority of cocaine samples.(2) As was the case when levamisole was used for various conditions in humans, we frequently see cocaine users with neutropenia and cutaneous vasculopathy.(3) In many of these cases, ANCA were specifically detected and in reports of cutaneous vasculopathy related to the use of cocaine adulterated with levamisole, histological studies often revealed a pattern consistent with leukocytoclastic vasculitis with or without thrombotic vasculopathy.(4)
The proper identification of cases related to levamisole-adulterated cocaine is of primary importance as the discontinuation of exposure is usually necessary and sufficient to reverse the pathology. Correct identification of these cases may prevent prolonged unnecessary use of immunosuppressive therapy.(4) It could also allow clinicians to offer the appropriate support for detoxification as the rate of recurrence of complications seems to be high after reexposure to levamisole, suggesting individual susceptibility.
Additionally, we note that cocaine alone is associated with midline destructive lesions where ANCA can also be detected.(4) Thus, we believe that cocaine use should be included in the differential of ANCA and vasculitic syndromes.
Alexandre Larocque MD
Centre Hospitalier de l’Université de Montréal – emergency medicine department
McGill University Health Center – clinical toxicology service
Centre Antipoison du Québec
Robert S. Hoffman MD
Associate Professor of Emergency Medicine and Medicine (Clinical Pharmacology)
New York University School of Medicine
Director, New York City Poison Center
1 Berden A, Goceroglu A, Jayne D, Luqmani R, Rasmussen N, Bruijn JA et al. Diagnosis and management of ANCA associated vasculitis. BMJ 2012; 344 :e26
2 Center for Disease Control and Prevention (CDC). Agranulocytosis associated with cocaine use: four states, March 2008 - November 2009. MMWR Morb Mortal Wkly Rep 2009; 58: 1381-5
3 Buchanan JA, Lavonas EJ. Agranulocytosis and other consequences due to use of illicit cocaine contaminated with levamisole. Curr Opin Hematol 2012; 19(1): 27-31
4 Specks U. The growing complexity of the pathology associated with cocaine use. J Clin Rheumatol 2011; 17(4):167-168.