Lipoprotein apheresis: an established therapeutic modality for homozygous familial hypercholesterolemia patients refractory to PCSK9 inhibitors: a case report and literature review.

Homozygous familial hypercholesterolemia (HoFH), is a rare genetic disorder characterized by dual mutations in the low-density lipoprotein receptor (LDLR) gene, leading to dysfunctional or absent LDLRs, often accompanied by severe premature Atherosclerotic Cardiovascular Disease (ASCVD) and exhibiting refractoriness to aggressive pharmacological interventions. Double filtration plasmapheresis (DFPP), a form of lipoprotein apheresis (LA), has been effectively utilized as an adjunctive treatment modality to reduce serum LDL-C levels in refractory cases of HoFH. Here, we report a case of a 36-year-old female with HoFH who developed xanthomas on her limbs and waist at age 7. Despite maximum-tolerated doses of statins from age 32, combined with ezetimibe and evolocumab, her LDL-C levels remained critically elevated at 12-14 mmol/L. Her genetic testing confirmed a homozygous LDLR mutation. At 35 years old, she experienced exertional chest pain, and percutaneous coronary intervention revealed severe calcific left main stenosis, necessitating stent implantation. Subsequently, she initiated once every 1-2 months DFPP. Pre-DFPP, her LDL-C and total cholesterol (TC) levels were 13.82 ± 3.28 and 15.45 ± 0.78 mmol/L, respectively. Post-DFPP, her LDL-C and TC levels significantly decreased to 2.43 ± 0.33 mmol/L (81.76 ± 4.11% reduction) and 3.59 ± 0.41 mmol/L (76.76 ± 2.75% reduction), respectively. Lipoprotein (a) and triglycerides also decreased by 89.10 ± 1.39% and 42.29 ± 15.68%,respectively. Two years later, there was no progression of coronary artery disease, and her symptoms and xanthomas regressed significantly. Collectively, DFPP effectively reduces LDL-C levels in refractory cases of HoFH and contributes to delaying ASCVD progression, representing an efficacious adjunctive therapeutic modality.