Rheumatic Manifestations of Cocaine Use

Jonathan Graf

Disclosures

Curr Opin Rheumatol. 2013;25(1):50-55. 

In This Article

Autoantibodies and Histopathology

With levamisole-associated disease, p-ANCA is positive by immunofluorescence at unusually high titres compared with those seen with classical MPA.[6,34] The antigen specificities for these p-ANCA are directed against multiple components of neutrophil granules, a feature observed in other drug (medication)-associated vasculitis. In our experience, p-ANCA titres can be greater than 1 : 20 480 in some patients, with the highest titres directed against HNE and other 'atypical' p-ANCA-associated antigens such as lactoferrin and cathepsin G.[6] Antibodies to myeloperoxidase (MPO) are occasionally detected, and when positive, are at relatively low titres compared with titres observed with the p-ANCA immunofluorescence. This discordance between p-ANCA immunofluorescence and MPO immunoassay is a striking hallmark of levamisole-associated autoimmunity that is not seen with classic MPA. Some of these p-ANCA-positive patients seem to paradoxically test positive for antibodies to PR-3. In these cases, it is not known whether or not the target of these PR-3 antibodies is to the same epitopes recognized by sera from GPA patients, different PR-3 epitopes or to homologous (cross-reacting) regions on p-ANCA-associated antigens such as HNE. The majority of patients with levamisole-associated disease also test positive for one or more antiphospholipid antibodies, including lupus anticoagulant and IgM predominant anticardiolipin and anti-beta 2 glycoprotein 1 antibodies.[6] Other autoantibodies are detected with varying frequency and specificity, including antinuclear and antidouble-stranded DNA antibodies. The predominant histopathology is an obliterative, small vessel thrombosis, with varying amounts of leurkocytoclastic vasculitis.[6,32]

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