Gabexate Mesylate as Treatment in the Course of ANCA-Negative Microscopic Polyangiitis

Abstract

Patients with small vessel vasculitis present fluctuating antineutrophil cytoplasmic antibodies (ANCA) levels to the point that positive ANCA may be missed even if only up to 10% of patients with microscopic polyangiitis (MPA) are ANCA-negative. The first-line treatment of MPA is the association of steroids and cyclophosphamide, especially in the presence of a rapidly progressive glomerulonephritis. Plasmapheresis, intravenous immunoglobulins, and tumor necrosis factor inhibitors have been proposed as alternative to standard therapy. Disseminated intravascular coagulation (DIC) is a possible event in the course of small vessel vasculitis. Gabexate mesylate is a protease inhibitor able to suppress endothelial cell injury, and it may be administered to treat DIC related to different diseases. In ANCA-associated vasculitis, cytokines play a key role in promoting endothelial damage. DIC-related thrombocytopenia may be misinterpreted as drug-induced because of the immunosuppressive properties of cyclophosphamide. Two cases of ANCA-positive MPA associated with DIC and treated with gabexate are reported in the literature with improvement of both hematological disorder and renal function. Our patient presented a rapidly progressive glomerulonephritis, and the renal biopsy showed MPA, in the absence of ANCA. After two weeks of steroid treatment, our patient developed a DIC. This case represents the first report of ANCA-negative MPA managed with gabexate, which showed improvement of coagulation disorders and kidney function. In conclusion, the anti-inflammatory properties of gabexate could be helpful in MPA at increased bleeding risk when immunosuppressive treatment is contraindicated, even in ANCA-negative vasculitis.

• gabexate mesylate
• microscopic polyangiitis
• ANCA
• disseminated intravascular coagulation
• immunosuppressive treatment