Lymphopenia and Treatment-Related Infectious Complications in ANCA-Associated Vasculitis

Summary Background and objectives ANCA-associated vasculitis (AAV) is treated with potent immunosuppressive regimens. This study sought to determine risk factors associated with infections during first-intention therapy. Design, setting, participants, & measurements This retrospective study involved two separate cohorts of consecutive cases of AAV seen from 2004 to 2011 at two university hospitals. The following were assessed: vasculitis severity; therapy; and periods with no, moderate (lymphocyte count, 0.3–1.0× 10 9 /L), or severe (lymphocyte count ≤ 0.3×10 9 /L) lymphopenia and neutropenia (neutrophil count ≤ 1.5×10 9 /L). Results One hundred patients had a mean age of 57±15 years and a Birmingham vasculitis activity score of 7.7±3.6. Therapy consisted of pulse methylprednisolone (59%), cyclophosphamide (85%), methotrexate (6%), and plasmapheresis (25%) in addition to oral corticosteroids. During follow-up, 53% of patients experienced infection and 28% were hospitalized for infection (severe infection). Only 18% experienced neutropenia, but 72% and 36% presented moderate and severe lymphopenia for a total duration of P P Conclusions Lymphopenia is frequent during the treatment of AAV, and its severity is associated with the risk of infectious complications.