Changes in plasma von Willebrand factor and von Willebrand factor cleaving protease in thrombotic thrombocytopenic purpura: A case report

The present case report described a patient with thrombotic thrombocytopenic purpura (TTP), who presented to the China-Japan Union Hospital of Jilin University (Changchun, China), and the changes in plasma von Willebrand factor (vWF) and vWF cleaving protease (vWF-cp) observed during treatment. Computed tomography and diffusion-weighted magnetic resonance (MR) imaging of the brain, cerebral MR angiography and other experimental tests were performed and the patient was subsequently diagnosed with TTP. The patient underwent treatment with plasma exchange, glucocorticoids and supportive care. Hematologic and biochemical parameters began to gradually improve over the 12 days after admission; platelet count, serum creatinine and serum lactate dehydrogenase concentrations returned to their normal ranges, plasma vWF concentration decreased to normal levels over the 30 days after admission, and vWF-cp activity increased compared with the levels detected in healthy volunteers. Monthly rituximab treatment was administered 4 times following patient discharge to prevent relapse, and no recurrence was detected at the 20-month follow-up. Plasma exchange therapy is effective in patients with TTP. After low-dose rituximab treatment, recurrent TTP has not been detected found till now. In the present case, vWF concentration and vWF-cp activity were measured at 8, 10, 23 and 32 days after admission; compared with the control group, patient's vWF concentration gradually decreased and vWF-cp activity slowly increased, suggesting that the patient had a favorable prognosis and a low risk of recurrence.