The Efficacy of Therapeutic Thrombocytapheresis in Patients with Thrombocytosis

Abstract

Objectives:

Therapeutic thrombocytapheresis (TTA), also known as platelet depletion, is used for rapid cytoreduction in symptomatic patients or prophylaxis of high-risk patients with extreme thrombocytosis. In this paper, we present our center’s nearly 20-year experience with TTA.

Materials and Methods:

The medical registry of Ankara University Faculty of Medicine Therapeutic Apheresis Unit was retrospectively reviewed for TTA procedures between January 1999 and December 2020.

Results:

One hundred and ninety-six TTA procedures were applied to 90 patients, including 46 (51.1%) males and 44 (48.9%) females. The median age was 52.5 years (18-83). Seventy-four (82.2%) patients with essential thrombocytosis, 5 (5.6%) with chronic myeloid leukemia, 5 (5.6%) with primary myelofibrosis, 3 (3.3%) with thrombosis in acute phase and 3 (3.3%) with others were treated. 61 (67.8%) patients had initial platelet count as <1,500x10⁹/L, 29 (32.2%) patients ≥1,500x10⁹/L. The median initial platelet count was 1,230x10⁹/L (545-3,825x10⁹/L). Thirty-three (36.7%) patients required >1 TTA procedures. The decrease of platelet count was 571.5x10⁹/L (72-3,128x10⁹/L) and 47.5% (6.2-92.4). After TTA, the PLT count was ≤450x10⁹/L in 19 (21.1%) patients, 450-1,000x10⁹/L in 56 (62.2%) patients, and≥1,000 x10⁹/L in 15 (16.7%) patients. The patients were divided into two groups according to initial platelet count. The decrease in platelet count was significantly higher in the group with PLT ≥1,500x10⁹/L [477x10⁹/L (72-1,644) vs 1,142x10⁹/L (363-3,128), respectively, p=0.001]. The rate of reduction was similar [46.1% (6.2-92.4) vs 50.9% (18.3-89.2), respectively, p=0.097].

Conclusion:

TTA can provide rapid reduction of platelet count and is suitable for patients with acute serious thrombotic or hemorrhagic events or high-risk patients with very high platelet counts.