[Thrombotic microangiopathy].

Area of Science:

• Hematology
• Neurology
• Pathology

Background:

• Thrombotic microangiopathies (TMAs) encompass thrombotic thrombocytopenic purpura (TTP) and hemolytic uremic syndrome (HUS), presenting with thrombocytopenia, microangiopathic hemolytic anemia, and organ dysfunction.
• Distinguishing TTP and HUS clinically is challenging due to overlapping symptoms, particularly neurological and renal manifestations.
• ADAMTS13 activity assays are pivotal in differentiating TTP (low activity) from HUS (normal activity).

Observation:

• Two cases of TMA were initially misdiagnosed as multiple sclerosis due to fluctuating neurological signs.
• Both patients developed thrombocytopenia, and platelet concentrate infusions exacerbated their conditions.
• Case 1 was diagnosed with intravascular lymphoma and acquired TTP, confirmed by deficient ADAMTS13 activity.

Findings:

• Case 2, despite suspected disseminated intravascular coagulation (DIC), ultimately received an autopsy-confirmed TMA diagnosis.
• Autopsy in Case 2 revealed widespread hyaline membrane thrombosis and absence of demyelinating lesions.
• The study highlights the diagnostic challenges and potential pitfalls in managing TMA patients.

Implications:

• TMAs can present with neurological symptoms mimicking primary neurological diseases, necessitating a broader differential diagnosis.
• The adverse effect of platelet transfusions in TMA underscores the importance of accurate diagnosis before intervention.
• Accurate and timely diagnosis of TMA, supported by ADAMTS13 testing, is critical for appropriate patient management and improved outcomes.