Supplementary Material for: Relapsing and Progressive Complications of Severe Hypertriglyceridemia: Effective Long-Term Treatment with Double Filtration Plasmapheresis

Background: Severe hypertriglyceridemia (HTG) is associated with major complications such as acute or relapsing pancreatitis (AP) and atherosclerotic cardiovascular disease (ASCVD). Rapid elimination of triglyceride (TG)-rich lipoproteins (LP) with double filtration plasmapheresis (DFPP) without need for substitution has been found to be effective for the acute, short-term treatment of HTG-induced AP. Data on the long-term use of DFPP to prevent HTG-associated complications are scarce. Objectives: To evaluate the use and efficacy of regular DFPP treatment in clinical practice for preventing recurrence of HTG-associated complications in thera­py refractory patients. Methods: Retrospective multicenter study in patients with severe symptomatic drug and diet refractory HTG with regular DFPP treatment. Patients’ incidence of HTG-associated pancreatic or cardiovascular complications was compared before treatment and with regular DFPP treatment. Results: Ten patients (3 female) were identified with baseline maximal TG concentrations of 2,587–28,090 mg/dL (median 5,487 mg/dL; interquartile range [IQR] 4,340–12,636). The mean observation period was 3.9 ± 3.4 years before and 3.8 ± 3.0 years after commencement of DFPP. In 5 patients, severe HTG was related to chylomicronemia, 2 patients had familial partial lipodystrophy Dunnigan, and 1 patient had additional LP(a)-hyperlipoproteinemia. The main HTG-associated complication was recurrent AP in 8 patients, including 1 patient treated during pregnancy. Two patients presented severe progressive ASCVD. With long-term DFPP treatment, the annual rate of HTG-associa­ted pancreatic or cardiovascular complications declined from median 1.4 (IQR 0.7–2.6) to 0 (IQR 0.0–0.4; p < 0.005). The absolute number of events was reduced by 77%. In 6 patients (60%) episodes of AP did not occur, nor was progression of ASCVD detected clinically or by routine imaging techniques. DFPP was effective in the elimination of TG-rich LP from plasma, and was safe and well-tolerated. Conclusion: Long-term, regular DFPP treatment resulted in stabilization of patients with severe HTG and related recurrent AP or progression of ASCVD, who were refractory to conventional dietary and drug therapy.