3b), target antigens of cytotoxic antineutrophil antibodies in the patients serum appeared to be translocated to the cell surface of the neutrophils by TNF-

3b), target antigens of cytotoxic antineutrophil antibodies in the patients serum appeared to be translocated to the cell surface of the neutrophils by TNF-. class=”kwd-title” Keywords: neutropenia, Graves disease, propylthiouracil, ANCA, autoantibody INTRODUCTION Drug-induced neutropenia is usually caused by a variety of mechanisms, including direct harmful effects and immunological reactions. As the immunological mechanisms, opsonizing neutrophils, neutrophil cytotoxicity and neutrophil agglutination by antineutrophil antibodies have been documented [1C4]. Due to the technical difficulties of detecting antibodies to neutrophils, however, the precise role and mechanisms of ONO-AE3-208 the antibodies in drug-associated neutropenia as well as the self-antigens have not yet been clarified. There have been recent studies of antineutrophil cytoplasmic antibodies (ANCA)-positive vasculitis associated with antithyroid drugs, especially propylthiouracil (PTU) [5C7]. Two different ANCA types have been explained using indirect-staining immunofluorescence (IIF):cytoplasmic staining (C-ANCA) and perinuclear staining (P-ANCA). Several ANCA antigens, such as proteinase 3 (PR3) and cathepsin G, are known to be translocated from your intracellular region to the plasma membrane and to be accessible ONO-AE3-208 to ANCA [8C11]. Although several studies have postulated a direct pathogenic effect of ANCA on vascular endothelial cells [12C14], only a few have documented the effects on neutrophils [15,16]. We examined a patient with Graves disease who developed both P- and C-ANCA after PTU treatment and exhibited leucopenia. In the present study we investigated if ANCA plays a pathogenic role in neutropenia, and found that ANCA killed differentiated HL-60 cells by a complement-dependent cytotoxicity. PATIENT AND METHODS Patient A 45-year-old Japanese woman, suffering from Graves disease, had been administered 300 mg PTU daily since 31 May 1991 (Fig. 1). She was admitted to hospital on 22 July 1997 due to neutropenia (WBC; 1700 l, neutrophils; 18% (306 l), lymphocytes; 78%, monocytes; 2%, eosinophils; 1%, basophils; 1%). Before PTU administration, her neutrophil counts were 2300C2600 l. Her neutropenia was noted on 2 August 1993 (1065 l) and 27 April 1994 (238 l) under 100 mg administration per day of PTU, but she recovered spontaneously without cessation of PTU on both occasions. Since July 1995, chronic neutropenia (98C1460 l) appeared under 50C75 mg per day of PTU and she was admitted for any radioisotope therapy to our hospital. After admission, PTU was discontinued and 131I] treatment was performed. Cessation of PTU resulted in the gradual increase of neutrophils. Serum at admission was positive in antinuclear ONO-AE3-208 antibody (homogeneous pattern), antithyroperoxidase antibody (78 U/ml, normal cut-off; 03 U/ml) and thyroid-stimulating antibody (10 U/ml bovine TSH comparative, normal cut-off; 03 U/ml), but unfavorable in antithyroglobulin antibody and TSH-binding inhibitor immunoglobulin. The complements levels were slightly low or lower normal (C3; 586 mg/dL (normal 66C153 mg/dL), C4; 209 mg/dL (normal 10C43 mg/dL), CH50; 351 U/ml (normal 28C51 U/ml)) despite the slight elevation of C-reactive protein (CRP) (03 mg/dL, normal cut-off; 02 mg/dL). Bone marrow aspiration at admission showed hypercellular marrow, compatible with neutrophil lysis in the peripheral blood. There were no symptoms or indicators that suggested vasculitis, such as fever, skin eruption, mononeuritis and proteinuria. Informed consent for the present study was obtained from this individual. Open in a separate windows Fig. 1 Changes in neutrophil counts and ANCA activities during PTU treatment. C131I]-Tx; radioisotope treatment by using radioiodine, 131I]. Measurement of ANCA P-ANCA and C-ANCA were recognized by the method of IIF [17,18]. Anti-MPO and anti-PR3 antibodies were measured by the enzyme-linked immunoadsorbent assay (ELISA) and their normal ranges are 13 MIF U/ml or 10 EU/ml [17,18], respectively. Preparation of neutrophils and HL-60 Peripheral blood mononuclear cells were isolated from heparinized venous blood of a normal individual by centrifugation through a Ficoll Hypaque gradient, as described previously [17]. Subsequently, neutrophils were separated with 2% methylcellulose (Sigma, St Louis, MO, USA) from reddish blood cells. The HL-60 promyelocytic leukaemia cell collection was a gift from Dr.