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Severe deficiency of VWF‐cleaving protease (ADAMTS13) activity defines a distinct population of thrombotic microangiopathy patients
Author(s) -
Raife Thomas,
Atkinson Bonnie,
Montgomery Robert,
Vesely Sara,
Friedman Kenneth
Publication year - 2004
Publication title -
transfusion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.045
H-Index - 132
eISSN - 1537-2995
pISSN - 0041-1132
DOI - 10.1111/j.1537-2995.2004.00626.x
Subject(s) - adamts13 , thrombotic microangiopathy , medicine , gastroenterology , von willebrand factor , thrombotic thrombocytopenic purpura , creatinine , population , platelet , disease , environmental health
BACKGROUND: Severe deficiency of ADAMTS13 activity is a biologic risk factor for thrombotic microangiopathy (TMA). It was hypothesized that severe ADAMTS13 deficiency is associated with a distinct TMA subpopulation. STUDY DESIGN AND METHODS: ADAMTS13 activity before treatment was determined retrospectively in 107 adult TMA patients treated with plasma exchange. Patients were not clinically categorized, but divided between severely deficient (n = 50) and nonseverely deficient (n = 57) ADAMTS13 activity. Laboratory and clinical factors before treatment were compared between the groups. RESULTS: Median PLT counts were 44,000 per µL in nonseverely deficient ADAMTS13 patients and 13,000 per µL in severely deficient ADAMTS13 patients (p < 0.001). Median serum creatinine levels were 2.7 mg per dL in nonseverely deficient patients and 1.2 mg per dL in severely deficient patients (p < 0.001). In surviving patients, median plasma exchange procedures were 9 in nonseverely deficient patients and 14.5 in severely deficient patients (p < 0.01). Rates of relapse following remission were 4 of 47 in nonseverely deficient patients and 16 of 46 in severely deficient patients (p < 0.01). Among analyzed factors only mortality rates were not significantly different. CONCLUSION: In a heterogeneous population of TMA patients treated with plasma exchange, ADAMTS13 activity defined two subpopulations with distinct clinical and laboratory features. These results suggest that TMA with severe ADAMTS13 deficiency is a distinct pathologic process.