Clinical Trial: Prophylactic Plasma Infusion Therapy for Congenital Thrombotic Thrombocytopenic Purpura

Study Status: Withdrawn
Recruit Status: Withdrawn
Study Type: Interventional

Official Title: Prophylactic Plasma Infusion Therapy for Congenital Thrombotic Thrombocytopenic Purpura

Brief Summary: Congenital thrombotic thrombocytopenic purpura (TTP), also called Upshaw-Schulman Syndrome or hereditary or familial TTP is a rare, but severe disease. The purpose of this study is to determine how infusions of plasma to patients with congenital TTP correlate with symptoms and signs of activity of the disease, and to determine why some patients need more frequent infusions of plasma than others to prevent acute attacks of the disease.

Detailed Summary: Patients with congenital TTP have an inherited lack of function or amount of a protein in plasma called ADAMTS13, that otherwise is responsible for cleaving large von Willebrand-molecules into smaller parts. The patients suffer recurrent attacks of clotting of small blood vessels, that can cause damage to major organs, including the central nervous system. Acute attacks can be treated successfully with infusions of human plasma, and some patients also receive regular plasma therapy for prevention of acute attacks. A small group of patients receive preventive plasma infusions twice or more weekly, indicating a much higher need for plasma than what is otherwise recommended for preventive therapy. Do these patients have an ongoing activity of their disease despite a stimulus? Or a higher turn-over of transfused ADAMTS13? Have these patients developed antibodies against transfused ADAMTS13? Are any symptoms correlated with signs of disease activity?
Sponsor: St. Olavs Hospital

Current Primary Outcome: A composite score of clinical and biochemical signs of disease activity [ Time Frame: 4 hours and 24 hours after intervention ]

Biochemical signs of disease activity are scored by measurements of lactate dehydrogenase, hemoglobin, platelet counts and ADAMTS13 activity.

Clinical signs of disease activity are measured by an evaluator's score and subjects symptom screening



Original Primary Outcome: Same as current

Current Secondary Outcome:

  • ADAMTS13 activity half-life [ Time Frame: 4 hours and 24 hours after intervention ]
    Calculation of half-life of ADAMTS13 activity based on serial measurements of ADAMTS13 activity before and after plasma infusions
  • ADAMTS13 allo-antibodies [ Time Frame: At baseline ]
    Presence of allo-antibodies towards ADAMTS13


Original Secondary Outcome: Same as current

Information By: St. Olavs Hospital

Dates:
Date Received: December 12, 2012
Date Started: September 2012
Date Completion:
Last Updated: December 18, 2012
Last Verified: December 2012