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Patterns of Platelet Response in Idiopathic TTP/HUS: Frequency of Declining Platelet Counts With Plasma Exchange and the Recognition and Significance of a Pseudo Refractory State
Author(s) -
Hay Shau,
Egan Jennifer A,
Millward Peter A,
Bandarenko Nicholas,
Brecher Mark E
Publication year - 2006
Publication title -
therapeutic apheresis and dialysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.415
H-Index - 53
eISSN - 1744-9987
pISSN - 1744-9979
DOI - 10.1111/j.1744-9987.2006.00368.x
Subject(s) - medicine , platelet , refractory (planetary science) , gastroenterology , mean platelet volume , thrombotic thrombocytopenic purpura , retrospective cohort study , physics , astrobiology
For thrombotic thrombocytopenic purpura (TTP), daily plasma exchange (TPE) is typically discontinued when the platelet count normalizes (>150 × 10 9 /L). We observed a decline in platelet count during TPE and in patients who appeared pseudo‐refractory because of a platelet count plateau (100–150 10 9 /L range). In the present study, we evaluated platelet count trends in TTP patients. Retrospective review of TTP patients from 01/1999 to 12/2004 was completed. Patients were categorized based on platelet count trends: Group I, counts rose then decreased to levels <100 × 10 9 /L; Group II, counts declined following TPE initiation; Group III, counts rose continuously; Group IV, counts decreased after the count was >100 × 10 9 /L. Additionally, we identified pseudo‐refractory patients caused by a platelet count plateau (>100 × 10 9 /L but <150 × 10 9 /L). We identified 60 TTP patients. Within Group I (17 patients/17 series/19.1% of total), the mean decrease in platelet count was 67.3% ± 22.1% following initial rise. Within Group II (24 patients/25 series/28.1% of total), the mean decrease was 28% ± 5.3% following presentation. Group III included 31 patients/39 series (43.8% of the total). Within Group IV (seven patients/eight series/9.0% of total), the mean decrease was 17.4% ± 12.6% following a sustained rise >100 × 10 9 /L. With a declining platelet count and daily TPE, it is generally sufficient to stay the course and the decline will reverse. Our limited experience with pseudo‐refractory patients supports discontinuing TPE when counts plateau between 100 and 150 × 10 9 /L when a therapy goal is a platelet count of 150 × 10 9 /L. Recognition of this pseudo‐refractory state can minimize the risks of prolonged TPE and the risks of adjunct interventions.