Function of Platelets Used for Transfusions

Thrombocytopenia Clinical Trial

Official title:

Flödescytometrisk utvärdering av Den Blodstillande förmågan Hos Trombocyter Avsedda för Transfusion

Clinical Trial Details — Status: Enrolling by invitation

Administrative data

• NCT number: NCT05038722
• Other study ID #: 2020-05968
• Status: Enrolling by invitation
• Start date: November 22, 2018
• Est. completion date: December 31, 2026

Study information

• Verified date: July 2023
• Source: Örebro University, Sweden
• Contact: n/a
• Is FDA regulated: No
• Study type: Observational

Clinical Trial Summary

Cytotoxic treatment for malignant hematologic disorders often casue thrombocytopenia that can result in life threatening bleedings. This is prevented by platelet transfusions but these can cause serious transfusion reactions and thus the number of transused platelet concentrates should be limited. It is therefore important that the platelet concentrates contain functional platelets with long circulation time in the bloodstream.

We have developed a method with flow cytometry to measure platelet function markers. It allows us to determine which pathways that are initiated upon activation.

The aim of this project is to assess to what degree spontaneous activation of platelets as well as their activation capacity affects the transfusion response (i.e. uptake in the circulation and circulation time) in the recipient.

The hypothesis is that transfusion of platelets with low spontaneous activation and high activation capacity will lead to a higher transfusion response in the recipient.

Description:

Cytotoxic treatment for malignant hematologic disorders often casue thrombocytopenia that can result in life threatening bleedings. This is prevented by platelet transfusions but these can cause serious transfusion reactions and thus the number of transused platelet concentrates should be limited. It is therefore important that the platelet concentrates contain functional platelets with long circulation time in the bloodstream.

The role of platelets in hemostasis is complex. Upon vascular injury, platelets adhere at the injured site where they become activated, release their granule content and aggregate. Activation include changes in receptors, expression of activation markers and become procaoagulant. We have developed a method with flow cytometry to measures these platelet function markers. It allows us to determine which pathways that are initiated upon activation.

Platelets can be stored a maximum of 5-7 days before transfusion. However, the preparation process and subsequent storage can result in platelet lesions, affecting their ability to promote hemostasis and circulate after transfusion.

The aim of this project is to assess to what degree spontaneous activation of platelets as well as their activation capacity affects the transfusion response (i.e. uptake in the circulation and circulation time) in the recipient.

The hypothesis is that transfusion of platelets with low spontaneous activation and high activation capacity will lead to a higher transfusion response in the recipient.

We will be able to examine how this relates to platelet processing methods and storage duration.

Platelets will be transfused on normal indications to participants at the hematology ward. The platelet concentrates choosen to be transfused will be done according to regular routines at the blood center. We will thus not control what concentrates are transfused (i.e. preparation method and storage time) and hence included in the study.

A small sample will be taken from the platelet concentrate shortly before transfusion and platelet function analysed with the flow cytometry method. Transfusion response will be assessed in the participant by calculation of corrected count increment (CCI) which relates the increase in platelet concentration after transfusion to the number of platelets transfused and the blood volume. CCI is calculated at 1 and 24-hours after transfusion. Clincial variables that might affect the transfusion response such as infection and fever will be registered as well as bleeding. The number of days to next platelet transfusion will be followed up.

Recruitment information / eligibility

• Status: Enrolling by invitation
• Enrollment: 240
• Est. completion date: December 31, 2026
• Est. primary completion date: December 31, 2025
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• Participant undergoing treatment for malignant hematologic disorders

• Thrombocytopenia

• Require platelet transfusion

Exclusion Criteria:

• Participant requiring HLA-matched platelet transfusions.

Related Conditions & MeSH terms

• Hematologic Malignancy
• Hematologic Neoplasms
• Thrombocytopenia

Intervention

Other:
• Platelet transfusion
Transfusion of platelet concentrates according to routine practice.

Locations

Country	Name	City	State
Sweden	Region Östergötland	Linköping
Sweden	Örebro University	Örebro

Sponsors (1)

Lead Sponsor	Collaborator
Sofia Ramström

Country where clinical trial is conducted

Sweden, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Corrected count increment (CCI)	CCI relates the increase in platelet concentration in participants after transfusion to the number of platelets transfused and the participants blood volume.	1- and 24 hours after transfusion.
Primary	Spontaneous and agonist induced expression of platelet activation markers on platelets in platelet concentrates.	Percentage of platelets expressing P-selectin, LAMP-1, phosphatidylserine and the active conformation of fibrinogen receptor.	Measured on the day of transfusion prior to transfusion.
Primary	Spontaneous and agonist induced formation of platelet subpopulations in platelet concentrates.	Percentage of normal sized platelets, small platelets and platelet fragments (microparticles).	Measured on the day of transfusion prior to transfusion.
Secondary	Treatment of infection.	Use of antibiotics.	Prior to transfusion.
Secondary	Signs of infection - fever.	Body temperature measurement.	Prior to transfusion.
Secondary	Bleeding.	Signs of bleeding according to WHO-scale (0-4, where 4 is the worst outcome).	Prior to platelet transfusion and 24-hours after the transfusion.
Secondary	Number of platelet transfusions	Total number of platelet transfusions a participant recieved before being incuded in the study (i.e before being transfused with the study specific platelet concentrate) in the treatment cycle.	From beginning of the cytotoxic treatment cycle to inclusion in the study, i.e receiving a study concentrate.
Secondary	Days to next platelet transfusion.	The number of days until the next platelet transfusion occured after being transfused with the study specific platelet concentrate.	After the study platelet concentrate was transfused, followed for up to two weeks after transfusion.