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

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.