effect of atorvastatin on endothelial dysfunction and albuminuria in sickle cell disease

Conditions: Sickle Cell Disease; Sickle Cell Nephropathy

Summary: the purpose of this research study is to learn about the effect of the drug, atorvastatin, on blood vessels in patients with sickle cell disease. the primary hypothesis is that endothelial dysfunction is an important contributor to the pathophysiology of albuminuria in scd. the investigators propose that atorvastatin will improve endothelial dysfunction, decrease levels of soluble fms-like tyrosine kinase-1 (sflt-1), and decrease albuminuria in scd patients. participants will be individuals with sickle cell disease, age 18 to 60, who have some degree of albuminuria. a total of 19 subjects, males and females, will be enrolled. the study is made up of screening, treatment, and follow up phases and has a cross-over design. after patients are screened for eligibility, they will be randomized to receive atorvastatin or placebo in the initial six-week treatment period. when that is complete, there will be a four-week washout period before they begin another six-week treatment period. in the second treatment period, they "cross-over" to the other treatment arm. four weeks after the end of the second treatment period, follow-up safety assessments will be done.

it is well recognized that sickle cell disease (scd) is characterized by a vasculopathy, with involvement of multiple organs including the brain, lung, spleen, and kidney. this results in multiple clinical complications, including ischemic stroke, pulmonary hypertension, autosplenectomy, as well as albuminuria and chronic renal disease. several recent studies have confirmed the association of both albuminuria and renal dysfunction with echocardiographically-defined pulmonary hypertension and other vasculopathic complications in scd, suggesting that they may share a similar pathophysiology. despite the high prevalence of albuminuria in patients with scd and the known association of renal failure with increased mortality, the pathophysiology and treatment of albuminuria in this setting remain poorly defined. the treatment options for nephropathy in scd are limited. although angiotensin converting enzyme (ace) inhibitors are the "standard of care" in the treatment of patients with proteinuria, there are to date no controlled, long-term studies confirming their efficacy and safety in this setting. in this study, the investigators will evaluate the efficacy and safety of atorvastatin in scd patients. at the completion of this trial, the investigators will have an improved understanding of the contribution of endothelial dysfunction to the pathophysiology of albuminuria in scd. if the data support the hypothesis that atorvastatin is safe and effective in this population, the investigators plan on carrying out adequately powered studies to more definitively evaluate its safety and efficacy in the treatment and/or prevention of albuminuria in scd.

Eligibility criteria:
inclusion criteria: 1. sickle cell anemia (hbss) or sickle-beta0 thalassemia (hbs-beta0thal) between ages of 18 and 60; 2. albuminuria (micro- or macroalbuminuria, defined as =/\> 30mg/g creatinine); 3. serum alanine aminotransferase (alt) \</= 2 times upper limits of normal and/or gamma-glutamyl transferase (ggt) \</= 3 times upper limits of normal; 4. platelet count \> 150,000 cu/mm; 5. normal baseline coagulation profile (pt, international normalized ratio (inr), and ptt); 6. non-crisis, steady state with no severe pain episodes during the preceding 4 weeks, and no documented infection in the 2 weeks prior to enrollment; 7. ability to understand the requirements of the study; 8. if a woman of childbearing potential, must use an adequate method of contraception; and 9. if receiving hydroxyurea, ace inhibitors or angiotensin blockers (arb), should be on a stable dose for at least 3 months. exclusion criteria: 1. hypersensitivity to any component of atorvastatin, or history of adverse reaction to statins; 2. pregnant or breastfeeding; 3. on statin therapy; 4. history of metastatic cancer; 5. current history of alcohol abuse; 6. history of diabetes mellitus or poorly controlled systemic hypertension; 7. end-stage renal disease; 8. total cholesterol level \ 130 mg/dl; 9. on a chronic transfusion program; 10. ingested any investigational drugs within the past 4 weeks; 11. prior history of any myopathy; 12. allergy to nitroglycerin; 13. taking any of the following drugs: phosphodiesterase-5 inhibitors (e.g., sildenafil), cytochrome p450 isoenzyme 3a4 (cyp3a4) inhibitors (e.g., cyclosporine, protease inhibitors), macrolide antibiotics (e.g., clarithromycin, erythromycin), fibric acid derivatives (e.g. gemfibrozil), niacin, colchicines, antifungal agents (azole derivatives), amiodarone, danazol, daptomycin, diltiazem, verapamil, eltrombopag, everolimus, fosphenytoin, or lanthanum. patients will also be encouraged to avoid grape fruit juice and red yeast rice for the duration of the study. atorvastatin is contraindicated during pregnancy and breast-feeding.

Keywords: sickle cell disease endothelial function albuminuria atorvastatin soluble fms-like tyrosine kinase-1