作者单位:Howard Univ Hosp, Dept Internal Med, Washington, DC USA[1]Howard Univ Hosp, Div Rheumatol, Washington, DC 20059 USA[2]Howard Univ Hosp, Dept Hematol & Oncol, Washington, DC USA[3]Howard Univ Hosp, Dept Pathol, Washington, DC USA[4]Georgetown Univ Hosp, Washington DC Vet Affairs Med Ctr, Washington, DC 20007 USA[5]