Hemostasis in Sickle Cell Disease--Infancy to Adulthood

To assess in older children and adults with sickle cell disease (SCD) whether intrinsic activation (relevant to the origin of pain and acute inflammation) occurs only during vasocclusive crisis (VOC).

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Key information

Conditions

Anemia, Sickle Cell Anemia Anemia, Hemolytic Anemia, Hemolytic, Congenital Blood Disease Congenital, Hereditary, and Neonatal Diseases and Abnormalities Genetic Diseases, Inborn Hematologic Diseases Hemic and Lymphatic Diseases Hemoglobinopathies

Age range

Up to 100 year

Sex eligibility

Male

Study type

Observational

About this study

BACKGROUND:

Investigations into hemostatic abnormalities associated with sickle cell disease have been numerous. The data suggested that thrombin generation and fibrin formation were increased during steady state, with conflicting data whether further activation occurred in vaso-occlusive crisis. Platelet activation during VOC occurred, with variable findings during steady state. A selective, concomitant evaluation of the hemostatic pathways i.e. intrinsic, tissue factor (TF) or extrinsic activation, fibrinolysis, and platelet-endothelial activation had not been reported. Neither had a longitudinal evaluation been performed in infants during the unique transition period when HbF levels fall from 70 to 80 percent to less than 10 percent.

The study was part of an initiative on "Coagulation, Platelets and Thrombosis in Sickle Disease Pathophysiology". The Request for Applications was released in October 1994.

DESIGN NARRATIVE:

The studies used appropriate 'negative' and 'positive' control groups. Studies included intrinsic markers [kininogen profiling, high molecular weight kininogen (HK) and low molecular weight kininogen (LK) cleavages, western blotting of HK and LK, and kallikrein-alpha2 macroglobulin; extrinsic markers [TF and factor V11a]; other activation and fibrinolytic markers [prothrombin F1.2, FPA, TAT, tPA, PAI-I, D-dimer and plasma alpha2 antiplasmin]; platelet- endothelial markers [evaluation of activation dependent epitopes]. Unequivocal demonstration of contact pathway activation during VOC provided a crucial link between VOC and its accompanying phenomenon including pain, and inflammation. Finally, the studies provided a unique perspective on the continuum of hemostatic changes that unfolded during the course of SCD, and those that developed as vascular insufficiencies supervened in the adult.

The study completion date listed in this record was obtained from the "End Date" entered in the Protocol Registration and Results System (PRS) record.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

No eligibility criteria

Sponsors and collaborators

Lead sponsor

National Heart, Lung, and Blood Institute (NHLBI)

Nih

Registry information

Important dates

Study start: 1995
Study completion: 1998
First posted: May 26, 2000
Registry last updated: May 13, 2016

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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Completed