A case of systemic lupus erythematosus having concurrent Evans syndrome and acquired thrombotic thrombocytopenic purpura

by Selleckchem | Mar 06 2023

An 18-year-old Japanese woman with systemic lupus erythematosus (SLE) experienced dyspnoea, headache, tinnitus, and purpura for two weeks and was admitted to our hospital. The patient had been diagnosed with SLE and secondary immune thrombocytopenia eight years before and treated with high-dose prednisolone (PSL) and mycophenolate mofetil. Since the blood test on admission showed haemolytic anaemia with a positive direct Coombs test and anti-glycoprotein IIb/IIIa antibodies, the patient was initially diagnosed with Evans syndrome (ES). The patient was treated with pulse intravenous methylprednisolone followed by 45 mg/day prednisolone; however, the patient's platelet count did not normalise. Based on a low level of a disintegrin-like metalloproteinase with thrombospondin type 1 motif 13 (ADAMTS-13) activity and a high level of ADAMTS-13 inhibitors, a diagnosis of acquired thrombotic thrombocytopenic purpura (TTP) was confirmed. After undergoing therapeutic plasma exchange for six consecutive days, the patient's platelet count recovered rapidly. Although concurrent acquired TTP and ES have not been reported previously, the findings from this case highlight the importance of measuring ADAMTS-13 activity and inhibitors to rule out acquired TTP, especially when ES is refractory to glucocorticoids.

Comments：

Systemic lupus erythematosus (SLE) and Evans syndrome (ES) are known autoimmune disorders that can lead to immune-mediated thrombocytopenia, which is characterized by a low platelet count. However, the presentation of dyspnoea, headache, tinnitus, and purpura in this patient raised suspicion of other underlying pathologies, such as acquired thrombotic thrombocytopenic purpura (TTP), which is a rare but life-threatening disorder.

The diagnosis of acquired TTP in this case was confirmed by a low level of ADAMTS-13 activity and a high level of ADAMTS-13 inhibitors. ADAMTS-13 is an enzyme that plays a crucial role in cleaving von Willebrand factor (vWF), a protein that promotes platelet adhesion and aggregation. In acquired TTP, the presence of inhibitors or autoantibodies against ADAMTS-13 results in decreased enzyme activity, which leads to the accumulation of ultra-large vWF multimers that cause microthrombi formation and platelet consumption.

Therapeutic plasma exchange (TPE) is the standard treatment for acquired TTP, and it was effective in this patient's case. The rapid recovery of platelet count after TPE suggests that the underlying pathophysiology of the patient's thrombocytopenia was primarily due to acquired TTP rather than ES.

This case highlights the importance of considering acquired TTP in patients with refractory immune-mediated thrombocytopenia, especially when they present with atypical symptoms such as dyspnoea, headache, and tinnitus. Measuring ADAMTS-13 activity and inhibitors is a crucial step in establishing the correct diagnosis and initiating prompt treatment with TPE.