An Imperfect Marker: SLE and TTP-Like MAHA Without Low ADAMTS13

Area of Science:

• Hematology
• Internal Medicine
• Rheumatology

Background:

• Thrombotic thrombocytopenic purpura (TTP) is a rare, life-threatening microangiopathic hemolytic anemia.
• Distinguishing TTP from autoimmune diseases like systemic lupus erythematosus (SLE) can be clinically challenging.
• Patients with SLE may present with TTP-like symptoms, complicating diagnosis.

Observation:

• A 44-year-old female with a history of SLE presented with anemia, thrombocytopenia, and altered mental status.
• Initial treatment for SLE-associated immune thrombocytopenic purpura was ineffective.
• The patient had mildly decreased ADAMTS13 levels, initially suggesting TTP but complicating the diagnostic picture.

Findings:

• The patient was treated with plasmapheresis (PLEX) for a suspected TTP-like microangiopathy.
• PLEX treatment led to significant improvement in platelet count and mental status.
• This response highlights the efficacy of PLEX in TTP-like conditions.

Implications:

• Clinicians should consider TTP-like microangiopathic hemolytic anemia in SLE patients with TTP symptoms, irrespective of ADAMTS13 levels.
• Early recognition and prompt initiation of PLEX are critical for favorable outcomes in these complex cases.
• This case underscores the importance of a broad differential diagnosis in patients with overlapping autoimmune and hematologic conditions.