Abstract
A 73-year-old man was admitted to our hospital because of fever, proteinuria, microscopic hematuria and elevated serum creatinine level (0.9→2.3 mg/dL) in July 2008. MPO-ANCA was detected in serum (83 EU), and renal biopsy showed pauci-immune crescentic glomerulonephritis. He was diagnosed with MPO-ANCA-related RPGN and was treated with intravenous methylprednisolone pulse therapy followed by oral prednisolone. Serum creatinine and MPO-ANCA titers decreased to 1.2 mg/dL and less than 10 EU, respectively. With tapering of the prednisolone dose, he was followed in the outpatient department. In January 2010, the titer of MPO-ANCA was re-elevated to 212 EU. In April 2010, serum creatinine was elevated to 4.5 mg/dL, and he was readmitted on May 17, 2010. Moreover anti-GBM antibody was detected (50 EU), and he received intravenous methylprednisolone pulse therapy to treat RPGN followed by oral prednisolone, and plasma exchange was initiated. Hemodialysis was performed because serum creatinine had increased to 6.1 mg/dL, but MPO-ANCA and anti-GBM antibody titers both decreased to less than 10 EU. From the beginning of July, his platelet count remained low, and fragmentation of red blood cells on peripheral blood smear and decreased haptoglobin levels were observed. A diagnosis of TTP was made, and plasma exchange was reinitiated. Plasma exchange was repeatedly performed in addition to administration of prednisolone, but the disease became resistant to extensive plasma exchange, leading to the death of the patient from pancreatitis and MOF on August 14. There have been several reports of a combination of TTP and either ANCA-related disease or anti-GBM antibody-related disease, but the combination of TTP and double antibody-positive RPGN is very rare. Here, we report a patient with double antibody-positive crescentic glomerulonephritis who developed refractory TTP.
