Genetics and Pain Severity in Sickle Cell Disease
|First Received Date ICMJE||September 24, 2011|
|Last Updated Date||May 23, 2013|
|Start Date ICMJE||September 2011|
|Primary Completion Date||Not Provided|
|Current Primary Outcome Measures ICMJE
||To determine if thresholds for pain perception are lower in SCD than in non-SCD controls.|
|Original Primary Outcome Measures ICMJE||Not Provided|
|Change History||Complete list of historical versions of study NCT01441141 on ClinicalTrials.gov Archive Site|
|Current Secondary Outcome Measures ICMJE
||To determine if variants in the GCH1 gene alter thresholds for pain perception in sickle cell disease.To determine if SCD subjects with higher GCH1 activity have 1) lower pain perception thresholds, 2) a higher prevalence of pain/VOC, 3) a...|
|Original Secondary Outcome Measures ICMJE||Not Provided|
|Current Other Outcome Measures ICMJE||Not Provided|
|Original Other Outcome Measures ICMJE||Not Provided|
|Brief Title ICMJE||Genetics and Pain Severity in Sickle Cell Disease|
|Official Title ICMJE||Exploratory Studies of Psychophysical Pain Phenotyping and Genetic Variability in Sickle Cell Disease|
- Pain is the most common symptom of sickle cell disease. Episodes of severe sickle cell pain are known as "crises." High rates of pain crises are associated with a higher risk of early death. Some people with sickle cell disease have many severe pain crises while others experience fewer crises. This difference in pain crisis may be caused by sensitivity to pain. People with high sensitivity to pain may have more pain crises. Many factors, including a person's genetic makeup, determine sensitivity to pain. Comparing genetic information from people with sickle cell disease and healthy volunteers may provide more information on pain and sickle cell disease.
- To study genetics and pain sensitivity in sickle cell disease.
Sickle cell disease (SCD) is the most common genetic disease in the United States inherited as an autosomal recessive disorder, where approximately 70,000 individuals have sickle cell disease. Acute painful vaso-occlusive crisis (VOCs) is one of the common complications of SCD that influences overall survival (Platt, Thorington et al. 1991). Pain, is also the most common cause of SCD morbidity, which has a negative impact on quality of life of these individuals and their families. There is significant inter-individual variation in the frequency and course of severe VOCs that result in hospital based treatment, the reasons for which have not been clearly elucidated. Vaso-occlusion of irreversibly sickle red cells within the microcirculation is believed to be the proximate cause of painful VOCs, however it is likely that other non-SCD related factors affecting pain perception and sensitivity to pain will also contribute to individuals' susceptibility to pain and therefore contribute to the observed inter-individual variability in the course of VOC. Early identification of individuals who are at high risk for developing severe pain related morbidity and chronic pain syndromes is crucial since early multimodal interventions might have the potential to minimize both the morbidity and mortality associated with VOCs.
Patients with SCD are hypothesized to have lower nitric oxide (NO) bioavailability due to NO scavenging by cell free hemoglobin released into plasma during red cell hemolysis. NO deficiency has been identified as a key factor in development vascular dysfunction in SCD. NO has also recently been identified as a key mediator in processing nociceptive signals and modulation of pain in non-SCD models. Thus, low NO is associated with lower pain perception (Meller, Dykstra et al. 1992; Tegeder, Costigan et al. 2006). GTP cyclohydrolase (GCH1) is the rate-limiting enzyme for synthesis of an essential cofactor for both NO production and metabolism of aromatic amino acids, namely tetrahydrobiopterin (BH4). Therefore it is hypothesized that genetic variants in the GCH1 gene will affect BH4 levels and which will have a secondary impact on vascular dysfunction and sensitivity to pain in SCD.
The primary goal of this protocol is to establish patterns of sensitivity to experimental pain among subjects with SCD compared to healthy African American controls. In addition, an exploratory analysis will determine if increased sensitivity to experimental pain correlates with the frequency and intensity of clinical pain in those with SCD. Once an expected pattern of experimental pain phenotypes are established for a cohort with SCD, we will then further explore the role of GCH1 genetic variants in experimental pain perception and vascular function. If successful, a longer term secondary objective is to establish a sufficiently large patient cohort with experimental pain phenotypes for future exploratory genetic studies to investigate the role of other loci that might influence sensitivity to experimental pain and vascular function in SCD.
|Study Type ICMJE||Observational|
|Study Design ICMJE||Not Provided|
|Target Follow-Up Duration||Not Provided|
|Sampling Method||Not Provided|
|Study Population||Not Provided|
|Intervention ICMJE||Not Provided|
|Study Group/Cohort (s)||Not Provided|
* Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
|Recruitment Status ICMJE||Recruiting|
|Estimated Enrollment ICMJE||60|
|Completion Date||Not Provided|
|Primary Completion Date||Not Provided|
|Eligibility Criteria ICMJE||
All study participants must be of self-described African or African American ancestry. They will be at least 18 years old and must be able to provide informed, written consent for participation.
Inclusion Criteria for Sickle Cell Patients
Inclusion Criteria for Control Subjects
Exclusion Criteria for Sickle Cell Patients
Exclusion Criteria for Control Subjects
|Ages||18 Years and older|
|Accepts Healthy Volunteers||Yes|
|Location Countries ICMJE||United States|
|NCT Number ICMJE||NCT01441141|
|Other Study ID Numbers ICMJE||110252, 11-H-0252|
|Has Data Monitoring Committee||Not Provided|
|Responsible Party||Not Provided|
|Study Sponsor ICMJE||National Heart, Lung, and Blood Institute (NHLBI)|
|Collaborators ICMJE||Not Provided|
|Information Provided By||National Institutes of Health Clinical Center (CC)|
|Verification Date||July 2012|
ICMJE Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP