Microscopic polyangiitis (MPA) is a type of necrotizing
vasculitis associated with high levels of
myeloperoxidase-specific
antineutrophil cytoplasmic antibody (MPO-
ANCA). While generally associated with renal dysfunction, MPA can also cause intraabdominal
hemorrhage in rare cases. A 66-year-old man was admitted to our hospital for renal dysfunction,
numbness, and
weight loss for 3 months. He had no significant medical history. Renal biopsy revealed crescentic
glomerulonephritis with necrotizing
vasculitis, which was associated with a high serum titer of MPO-
ANCA, leading to a diagnosis of MPA.
Remission-induction treatment with
glucocorticoids and
rituximab was initiated, which improved the patient's general condition and
renal failure. His blood pressure was elevated and was controlled by
amlodipine treatment. Two months after discharge, he visited the emergency department because of
chest pain. A diagnosis of acute cardiovascular syndrome was suggested; however, his cardiac artery was not stenotic. The patient's blood pressure was high despite
antihypertensive therapy, and he developed
posterior reversible encephalopathy syndrome (PRES). Despite intensive treatment, the patient died 3 days later. An autopsy revealed that the cause of death was
hypovolemic shock due to massive intra-abdominal
hemorrhage from the ruptured mesenteric artery involved in
vasculitis. In cases of MPA with sudden-onset chest or
abdominal pain, a ruptured intra-abdominal artery should be considered. Secondary
hypertension associated with
vasculitis should be carefully managed to prevent hemorrhagic complications and PRES.