Related Experiment Video
Updated: Mar 18, 2026
Electroencephalography Network Indices as Biomarkers of Upper Limb Impairment in Chronic Stroke
Published on: July 14, 2023
Correlation between ADAMTS13 activity and neurological impairment in acute thrombotic microangiopathy patients
Giulia Berti de Marinis1, Stefano Novello2, Silvia Ferrari2
1Emergency Department, University Hospital of Padova, Via Giustiniani n.2, 35128, Padua, Italy. giulia.bdm@gmail.com.
Abstract:
Differential diagnosis between thrombotic thrombocytopenic purpura (TTP) and other thrombotic microangiopathies (TMA) is usually difficult because of frequently overlapping clinical presentations. Severely depressed ADAMTS13 activity (<10 %) seems distinctive for TTP because of its pathogenetic role. However a long debate exists in the literature about its sensibility and specificity. Our aim was to search for clinical differences between TMA patients referred to our laboratory, comparing them for protease activity <10 versus ≥10 %. ADAMTS13 activity ≥10 % patients (n = 73) showed a higher prevalence of drug- (p = 0.005) and cancer-associated (p < 0.001) TMA. Mean platelet count and renal dysfunction prevalence was lower (p < 0.001), while neurological impairment was more frequent (p = 0.001) in the <10 % ADAMTS13 activity group (n = 109), confirming previous literature findings. When taken neurological manifestations singularly, epilepsy (p = 0.04), focal motor deficit (p < 0.001) and cranial nerve palsy (p = 0.007) were more frequent in the <10 % activity group. In our case series, a <10 % ADAMTS13 activity depicts a group of patients with clinical features similar to TTP patients. Focal motor impairment or epileptic manifestations could further address toward a TTP diagnosis. Studies about treatment efficacy and follow-up are advised to determine whether laboratory findings can guide therapeutic decisions.
Insights
Distinguishing thrombotic thrombocytopenic purpura (TTP) from other thrombotic microangiopathies (TMA) is challenging. Severely low ADAMTS13 activity (<10%) is linked to TTP, with neurological symptoms like epilepsy and focal deficits suggesting this diagnosis.
Area of Science:
- Hematology
- Internal Medicine
- Pathophysiology
Background:
- Differentiating thrombotic thrombocytopenic purpura (TTP) from other thrombotic microangiopathies (TMA) presents diagnostic challenges due to overlapping clinical features.
- Severely depressed ADAMTS13 activity (<10%) is considered a hallmark of TTP, though its sensitivity and specificity remain debated.
- Understanding clinical distinctions based on ADAMTS13 activity levels is crucial for accurate diagnosis and management of TMA.
Purpose of the Study:
- To investigate clinical differences between TMA patients with ADAMTS13 activity <10% versus ≥10%.
- To identify specific clinical features that may aid in distinguishing TTP from other TMAs.
- To evaluate the diagnostic utility of ADAMTS13 activity levels in TMA patient stratification.
Main Methods:
- Retrospective analysis of TMA patients referred to the laboratory.
- Comparison of clinical presentations between patients with ADAMTS13 activity <10% (n=109) and ≥10% (n=73).
- Statistical analysis to determine the significance of observed clinical differences, including specific neurological manifestations.
Main Results:
- Patients with ADAMTS13 activity ≥10% exhibited a higher prevalence of drug- and cancer-associated TMA.
- The <10% ADAMTS13 activity group showed lower mean platelet counts and less renal dysfunction but more frequent neurological impairment.
- Epilepsy, focal motor deficits, and cranial nerve palsy were significantly more common in the <10% ADAMTS13 activity group.
Conclusions:
- A <10% ADAMTS13 activity in TMA patients is associated with clinical features resembling TTP.
- Specific neurological manifestations, such as focal motor impairment and epilepsy, may indicate TTP.
- Further research on treatment efficacy and follow-up is recommended to guide therapeutic decisions based on laboratory findings.
