Efficacy and Selectivity of a Direct Absorption of Lipoproteins Apheresis System in Familial Hypercholesterolemic Omani Patients

Abstract

Synopsis: Direct absorption of lipoproteins (DALI) has been shown as an effective means of apolipoprotein B (apoB)-containing lipoprotein removal from whole blood in patients with familial hypercholesterolemia. Purpose: To describe the efficacy and selectivity of the DALI apheresis system in Omani patients with familial hypercholesterolemia. Methods: DALI apheresis therapy for refractory hypercholesterolemia was first started in March 2008 in Oman. We have treated five patients to date, four with homozygous familial hypercholesterolemia, and one with severe heterozygous familial hypercholesterolemia who had undergone cardiac bypass surgery. All patients were treated with high-dose statins and ezetimibe. For each treatment, 1.6-fold of the calculated blood volume was processed. Treatments were scheduled at weekly or biweekly intervals. On average 5500 mL of the patients' whole blood was processed in about 2 hours. Anticoagulation in the extracorporeal system was carried out by continuous addition of an acid citrate dextrose (ACD-A) infusion during treatment at a ratio of 1:40. Results: The average total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglyceride, apoA, and apoB before and after treatment in all patients were: 8.3 ± 1.8 vs 4.0 ± 0.8 (% reduction 51), 6.8 ± 1.4 vs 2.9 ± 0.6 (% reduction 57), 0.9 ± 0.1 vs 0.8 ± 0.1 (% reduction 7), 1.7 ± 1.2 vs 1.1 ± 0.9 (% reduction 33) mmol/L, 0.96 ± 0.65 vs 0.87 ± 0.78 (% reduction 10), and 1.9 ± 0.4 vs 0.9 ± 0.2 (% reduction 53) g/L, respectively. Long-term evaluation of biochemistry tests showed a percentage reduction of less than 10% in postapheresis treatment except for sodium (11%), glucose (14%), and phosphate (22%). Hemoglobin and platelets were not significantly affected. As expected, postapheresis activated partial thromboplastin time was significantly increased from 33 ± 1 to 104 ± 30, with no changes to prothrombin time and international normalized ratio. No serious side effects occurred during the treatment. Conclusions: The DALI apheresis system is very effective for the direct removal of apoB-containing lipoproteins from whole blood; it is selective and is well tolerated.