The Statistical and Data Management Center (SDMC)

The Statistics and Data Management Center (SDMC) at Rho, Inc. performs all of the statistical and data management functions for the Comprehensive Sickle Cell Centers (CSCC), a group comprised of 10 sickle cell research centers across the country and funded by the National Heart, Lung, and Blood Institute (NHLBI), a division of the National Institutes of Health (NIH). In addition, the SDMC acts as a coordinating center for the various multi-center and single center trials.

Sickle Cell Disease

Sickle Cell Disease is a group of related genetic disorders that affect red blood cells. Sickle Cell Anemia (SCA) is the most prevalent form, but other forms such as hemoglobin SC disease and sickle beta-thalassemia are also common. All forms of sickle cell disease are marked by anemia (a low red blood cell count) and by crescent-shaped red blood cells. Normal hemoglobin is called hemoglobin A, but people with sickle cell disease have only hemoglobin S, which turns normal, round red blood cells into abnormally curved (sickle) shapes.

The Comprehensive Sickle Cell Centers (CSCC) Program was established by the Sickle Cell Disease Control Act of 1972. In response to this Presidential initiative and Congressional mandate, the NHLBI established a National Sickle Cell Disease Program to include comprehensive research centers selected by open competition every 5 years. For the first time, in the 2003-2008 funding cycle, a mechanism for Inter-Center clinical trials was included to enable the 10 funded CSCCs to carry out multi-center translational research focused on the development of curative therapies and the improvement of medical treatment of sickle cell disease. This Comprehensive Sickle Cell Centers Clinical Trials Consortium (CSCC-CTC) establishes research priorities, and designs and conducts large multi-center investigations to address these broad goals.

Current Multi-Center Projects Supported by the SDMC

Arginine Supplementation in Sickle Cell Anemia: Physiological and Prophylactic Effects

Nitric oxide is an important inflammatory mediator produced from arginine by nitric oxide synthase. Nitric oxide has a multitude of functions which could impact favorably on vaso-occlusion in sickle cell disease. Oral arginine has been shown to raise levels of nitric oxide. This study will test whether daily oral arginine results in an increase in nitric oxide and other beneficial effects in patients with sickle cell disease. The results of this study will serve as the basis for further clinical trials to determine if daily arginine is a beneficial therapy for patients with sickle cell disease.

Comprehensive Sickle Cell Centers Collaborative Data Project

The Comprehensive Sickle Cell Centers (CSCC) Collaborative Data Project will establish a comprehensive database of individuals from participating Centers who are potentially eligible for inclusion in any sickle cell research study. Such studies include observational (incidence/prevalence, cohort, case-control, cross-sectional) as well as interventional (randomized clinical trials) investigations. Possible study endpoints include traditional clinical and therapeutic measurements, health resource utilization, and patient-reported outcomes. The Collaborative Data Project encompasses these clinical and outcomes databases within the Patient Database component of the Project, and includes additional components of specifically developed tools and methodologies required for practical, quality data capture, management, and utilization. A secure web-based Electronic Data Capture system will be provided to Centers to allow data submission to the Statistics and Data Management Center. Adherence to all Federal Guidelines regarding privacy and confidentiality will be rigorously maintained.

Neuropsychological Dysfunction and Neuroimaging Abnormalities in Neurologically Intact Adult Patients With Sickle Cell Disease (SCD)

In Phase I, approximately 156 subjects will participate in a cross-sectional study consisting of screening questionnaires, a neuropsychological testing battery, and MRI testing. In Phase II, a subset of approximately 30 participants will be asked to participate in a transfusion intervention. Half will be randomized to undergo a chronic transfusion regimen for six months, and the other half will be treated with standard care alone, guided by their disease symptoms.

Epidemiology of Priapism

Priapism, a prolonged erection of the penis that may lead to impotence, is a specific type of painful crisis that commonly occurs in patients with sickle cell disease. The current treatment of priapism can be improved by comparing therapeutic strategies in prospective clinical trials, but first an assessment of the natural history of priapism is needed. This project will conduct an interview of 1,650 males with sickle cell disease in order to determine in which patients, how often, and under what circumstances priapism occurs.

Effectiveness of Hydroxyurea and Magnesium Pidolate Alone and in Combination in Hemoglobin SC Disease: A Phase II Trial

Hemoglobin (Hb) SC disease is characterized by dense red blood cells, but treatment approaches aimed at its pathophysiology have been limited in scope. Furthermore, combination drug therapy in sickle cell disease has not been adequately tested. We will examine two oral therapies, hydroxyurea and magnesium, given by themselves and in combination and compare them to placebo in a double-blinded Phase II study to determine their efficacy in reducing red cell density in Hemoglobin SC in children and adults. We will also examine their effects on other red cell characteristics and on the frequency of clinical vaso-occlusive events. To accomplish this, 188 subjects will be assigned randomly to one of four treatment groups (see below) and followed for one year after beginning treatment.