Extracorporeal plateletpheresis induces the interaction of activated platelets with white blood cells

Regulated upon activation, normal T cells expressed and secreted (CCL5) in platelet concentrate: Role of mode of preparation and duration of storage

BACKGROUND AND OBJECTIVES:

Platelet concentrates (PCs) can be prepared in several different ways, and they can be stored over few days before the use. Regulated on activation, normal T cells expressed and secreted (RANTES) levels in these concentrates may vary depending on the type of preparation and duration of storage of this component. We measured RANTES levels in platelet supernatants in different preparations and with different storage duration.

MATERIALS AND METHODS:

Fifteen PCs were prepared by platelet-rich plasma (PRP) and buffy coat (BC) method each. Forty-two single donor platelets (SDPs) were prepared using cell separators Cobe Spectra, Trima Accel, and Amicus. Filtered PCs were prepared using labside and bedside filters. The supernatants were collected after 1, 18, 65, and 112 h of preparation. SDP samples were taken on the 0 day, 3^rd day, and 5^th day. In filtered PC, pre- and post-filtration samples were taken, and aliquots were frozen at − 56°C for the measurement of RANTES.

RESULTS:

RANTES at 1 h was 1210 ± 560 pg/ml in PRP-PC, 1384 ± 463 pg/ml in BC-PC. At 112 h, 1617 ± 451 pg/ml and 1949 ± 134 pg/ml, respectively. In SDP, 0-day level was 1850 ± 278 pg/ml and >2000 pg/ml on 5^th day. In prestorage, filtered PC RANTES was 1035 ± 496 pg/ml, and in the poststorage sample, it was 310 ± 508 pg/ml. With bedside filters, presample showed 1243 ± 832 pg/ml and postsample showed 556 ± 748 pg/ml.

CONCLUSION:

The concentration of RANTES increased continuously from 1 h to 5 days of storage in all PCs. After 65 h, BC-PC showed higher levels of RANTES compared to PRP-PC. Filtered PRP-PCs appear to be the best in terms of low RANTES to prevent allergic reactions and cultures negative.

The role of thrombocytapheresis in the contemporary management of hyperthrombocytosis in myeloproliferative neoplasms: A case-based review

Extreme thrombocytosis induces an acquired thrombotic-hemorrhagic diathesis, and left uncontrolled is a harbinger of potentially fatal vascular complications. Currently, cytoreduction with medical therapy remains the mainstay of hyperthrombocytosis management. However, it offers a less-than-ideal option in situations where a rapid reduction in platelets is urgently needed, as in the presence of vital end-organ ischemia or to ameliorate of life-threatening hemorrhage. The role of thrombocytapheresis, or plateletpheresis, in hyperthrombocytosis has become increasingly obsolete given the proactive titration of cytoreductive therapies and early identification and correction of reversible causes of reactive thrombocytosis. Despite its narrowed indications, plateletpheresis continues to offer a valuable temporizing measure in platelet count reduction before cytoreductive agents exert their maximal effect. In this context, it is important for the treating physician to be aware of the symptoms and risks associated with hyperthrombocytosis to inform best clinical practices. In this review, we discuss the role of plateletpheresis in the modern-day management of hyperthrombocytosis in patients with myeloproliferative neoplasms through a case based review of the literature. It becomes apparent throughout the discussion that the decision to perform plateletpheresis should be individualized based upon the clinical scenario, degree of thrombocytosis, available infrastructure and every patient's risk profile.

Comparison of flow cytometry vs. a haematology cell analyser-based method to guide the optimal time-point for peripheral blood stem cell apheresis

BACKGROUND AND OBJECTIVES

For timing the onset of apheresis, parameters obtained by flow cytometry and by a haematological cell analyser were compared.

MATERIALS AND METHODS

Haematopoietic cell counts (n = 159) were performed by two different methods; CD34 analyses by flow cytometry, immature myeloid information (IMI) and human progenitor cell counts (HPC) by a haematological cell analyser.

RESULTS

Comparing the IMI total results with CD34+ analyses (n = 159) revealed a correlation of r = 0.46 (P < 0.05). Similar results were obtained for HPC (r = 0.44; P < 0.05).

CONCLUSION

The haematology analyser-based method does not allow the precise determination of absolute haematopoietic stem cell numbers and is thus not able to replace flow cytometry for the monitoring of peripheral blood stem cell counts.