| Background: Thrombotic microangiopathy (TMA) is a rare but devastating small vessels disorder that is characterized by intravascular
platelet thrombi, thrombocytopenia, and various degrees of organ ischemia and anemia, which is due to erythrocyte fragmentation in
microcirculation.
Objectives: The Aim of this study was to determine the von Willebrand factor-cleaving protease (ADAMTS13) activity during the acute
phase of TMA. We also investigated inhibiting antibodies against ADAMTS13 in these patients.
Patients and Methods: In a collaborative work with Mario-Negro institute of pharmacological research in Bergamo-Italy, we registered
the clinical and laboratory data, collected the serum samples, and transferred the samples to the laboratories. Serum samples were taken
before the start of plasmapheresis or at least 15 days after the fnal exchange.
Results: We recruited 40 patients (14 males and 26 females) with the mean age of 46.12 ± 17.26 years. The mean activity of ADAMTS13 was
34.58% ± 21.83%. Two patients had inhibitory antibodies against ADAMTS13 with profound defciency of ADAMTS13 activity (< 6%). Infectious
diseases were the most common underlying condition, followed by systemic lupus erythematous.
Conclusions: Majority of patients had an underlying condition and had various ADAMTS13 activity. The presence of inhibiting antibodies
and accompanied complete defciency of ADAMTS13 activity is an indicator of severity. |