Viscidi RP, Khanna N, Tan CS, Li X, Jacobson L, Clifford DB, Nath A, Margolick JB, Shah KV, Hirsch HH, Koralnik IJ. JC virus antibody and viremia as predictors of progressive multifocal leukoencephalopathy in human immunodeficiency virus-1-infected individuals. Clin Infect Dis. 2011 Oct; 53(7):711-5.