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Von Willebrand factor-cleaving protease activity in thrombotic microangiopathy: first report from iran
Mohammadreza Ardalan1, Parisa Rezaeifar1
1Chronic Kidney Disease Research Center, Tabriz University of Medical Sciences, Tabriz, IR Iran.
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 final 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 deficiency 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 deficiency of ADAMTS13 activity is an indicator of severity.
Insights
Thrombotic microangiopathy (TMA) patients often have underlying conditions and varied ADAMTS13 activity. Inhibiting antibodies and severe ADAMTS13 deficiency indicate a worse prognosis in TMA.
Area of Science:
- Hematology
- Internal Medicine
- Pathology
Background:
- Thrombotic microangiopathy (TMA) is a rare disorder of small blood vessels.
- Characterized by platelet thrombi, low platelets, organ damage, and anemia due to red blood cell fragmentation.
Purpose of the Study:
- To measure von Willebrand factor-cleaving protease (ADAMTS13) activity during acute TMA.
- To identify antibodies inhibiting ADAMTS13 in TMA patients.
Main Methods:
- Clinical and laboratory data were collected from 40 TMA patients.
- Serum samples were analyzed for ADAMTS13 activity and inhibitory antibodies.
- Samples were taken before plasmapheresis or after the final exchange.
Main Results:
- Mean ADAMTS13 activity was 34.58%.
- Two patients (5%) had inhibitory antibodies and severe ADAMTS13 deficiency (<6%).
- Infectious diseases and systemic lupus erythematosus were common underlying causes.
Conclusions:
- Most TMA patients have an underlying condition and diverse ADAMTS13 activity levels.
- Presence of inhibitory antibodies and profound ADAMTS13 deficiency suggests increased disease severity.
