Table 2.

Patients with a diagnosis of AAV, previously IF-positive, MPO/PR3-positive, who then had an IF-negative, MPO/PR3-positive result after therapy.

Clinical Diagnosis	Age, yrs	Prior IF	Prior Antibody	Antibody Titer When IF-negative	Documented Therapies
MPA	60	P-ANCA	MPO+	MPO 102	CS
MPA	54	P-ANCA	MPO+	MPO 92	CS, CYC, AZA
CSS	79	C-ANCA	MPO+	MPO 37	CS, MTX
Drug-induced vasculitis	59	P-ANCA	MPO+	MPO 38	CS
GPA	72	C-ANCA	PR3+	PR3 59	CS, CYC, MTX, AZA
GPA	61	C-ANCA	PR3+	PR3 90	CS, RTX, AZA
GPA	52	C-ANCA	PR3+	PR3 93	CS, CYC, AZA
GPA	69	C-ANCA	PR3+	PR3 98	CS, RTX
GPA	53	C-ANCA	PR3+	PR3 110	CS, MTX
GPA	43	C-ANCA	PR3+	PR3 273	CS, RTX, MTX
GPA	57	C-ANCA	PR3+	PR3 33	CS, RTX, MTX

AAV: ANCA-associated vasculitis; IF: immunofluorescence; MPO: myeloperoxidase; PR3: proteinase 3; MPA: microscopic polyangiitis; CSS: Churg-Strauss syndrome; GPA: granulomatosis with polyangiitis; P-ANCA: perinuclear ANCA; C-ANCA: cytoplasmic ANCA; CS: corticosteroids; CYC: cyclophosphamide; AZA: azathioprine; MTX: methotrexate; ANCA: antineutrophil cytoplasmic antibodies; RTX: rituximab.