Low-density lipoprotein apheresis for refractory lupus nephritis: A case demonstrating marked improvement in proteinuria, hematuria, and renal function.

Systemic lupus erythematosus (SLE) predominantly involves the kidneys, causing lupus nephritis. Patients with diffuse proliferative lupus nephritis frequently experience poor outcomes despite advances in immunosuppressive therapies. Low-density lipoprotein apheresis (LDL-A) has been a potential therapeutic option for steroid-resistant nephrotic syndromes, but its efficacy in lupus nephritis remains unknown. Here, we report the case of a 26-year-old female patient with SLE and renal pathology society classification IV + Ⅴ (G) A/C lupus nephritis who developed refractory nephrotic syndrome, severe hematuria, and declining renal function. Initial induction therapy was insufficient. Consequently, LDL-A significantly improved proteinuria, hematuria, and renal function. The urinary protein-to-creatinine ratio decreased from 7.15 g/gCr to 0.610 g/gCr, and hematuria dropped from >100 to 10-19 erythrocytes per high-power field. Additionally, complement levels were improved and anti-double-stranded DNA antibody titers were reduced. Ascribing these improvements solely to LDL-A remains challenging, but the rapid proteinuria and hematuria reduction within 48 h indicates a substantial contribution of LDL-A to the clinical response. The effluent from LDL-A contained not only LDL cholesterol but also measurable amounts of IgG and IgM, which may have contributed to the reduction in lupus nephritis activity. This case represents the first report of a marked hematuria reduction following LDL-A in lupus nephritis. LDL-A is a valuable adjunctive treatment in patients with refractory nephrotic syndrome or highly active lupus nephritis unresponsive to conventional induction therapies.