Scientists hunt for clot clues in sickle cell blood

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

* INCLUSION CRITERIA: Sickle cell disease with and without VTE * Sickle cell disease (HbSS, HbSC and HbS/beta-thalassemia genotypes) in steady state. * Diagnosis of at least one or more VTE within 5 years of study enrolment confirmed by radiologic imaging (for SCD patients with VTE). * Absence of clinical history of VTE (for SCD controls) * Between 18 and 80 years of age. * Ability to provide informed written consent. Sickle cell trait * Sickle cell disease (HbAS genotype). * Absence of clinical history of VTE * Between 18 and 80 years of age. * Ability to provide informed written consent. Ethnically matched controls * Between 18 and 80 years of age. * African, or of African descent. * Ability to provide informed written consent. * Absence of clinical history of VTE EXCLUSION CRITERIA: SCD with and without VTE * Pregnancy (test done at enrollment; if a subject becomes pregnant during the study period, samples will not be obtained while the subject is pregnant and the subject will be taken off study). * Patients on exchange transfusion or having received a simple blood transfusion in the past 60 days. * Active viral infection as evidenced by testing positive for hepatitis B surface antigen or hepatitis C virus (HCV) antibody (Ab) with signs of active hepatitis B or C virus infection. If the subject is positive for HCV Ab, a reverse transcriptasepolymerase chain reaction test will be conducted. Subjects with hepatitis C may be rescreened after receiving appropriate hepatitis C treatment. * Testing positive for human immunodeficiency virus 1 or 2 Ab with evidence for ongoing active infection (i.e., CD 4 count \<400/microL and viral load \>100,000 copies/ml) on antiretroviral therapy. * Active acute inflammatory disorders rheumatoid arthritis or systemic lupus erythematosus on disease modifying therapy. * Diabetes mellitus judged to be under poor control by the Investigator evidenced by a single fasting sugar value \>250gm/dl or requiring \>3 antidiabetic agents, including insulin (all insulins are considered 1 agent); use of insulin per se is not exclusionary. SCT and ethnically matched controls * Diagnosis of any of the following chronic disease or conditions: Sickle cell disease (HbSS, HbSC and HbS/beta-thalassemia genotypes). * Clinical history of VTE. * Pregnancy (test done at enrollment; if a subject becomes pregnant during the study period, samples will not be obtained while the subject is pregnant and the subject will be taken off study. * Active viral infection as evidenced by testing positive for hepatitis B surface antigen or hepatitis C virus (HCV) antibody (Ab) with signs of active hepatitis B or C virus infection. If the subject is positive for HCV Ab, a reverse transcriptasepolymerase chain reaction test will be conducted. Subjects with hepatitis C may be rescreened after receiving appropriate hepatitis C treatment. * Testing positive for human immunodeficiency virus 1 or 2 Ab with evidence for ongoing active infection (i.e., CD 4 count \<400/microL and viral load \>100,000 copies/ml) on antiretroviral therapy. * Active acute inflammatory disorders rheumatoid arthritis or systemic lupus erythematosus on disease modifying therapy. * Diabetes mellitus judged to be under poor control by the Investigator evidenced by a single fasting sugar value \>250gm/dl or requiring \>3 antidiabetic agents, including insulin (all insulins are considered 1 agent); use of insulin per se is not exclusionary.