Is IVIG Removed by Dialysis?
No, IVIG (Intravenous Immunoglobulin) is not significantly removed by dialysis due to its high molecular weight (approximately 150 kDa), which far exceeds the pore size of standard dialysis membranes.
Pharmacokinetic Properties of IVIG
IVIG is not cleared by hemodialysis because of several key characteristics 1:
- High molecular weight (~150 kDa) prevents passage through dialysis membranes
- Wide distribution into tissues throughout the body
- High degree of protein binding (>90%)
- Metabolism occurs primarily through the reticuloendothelial system, not renal clearance
These properties are analogous to rifampin, which similarly is not removed by dialysis due to high molecular weight, tissue distribution, and protein binding 1.
Clinical Implications for ESRD Patients
Dosing Considerations
Standard IVIG dosing can be used in patients with end-stage renal disease without adjustment for dialysis 1:
- No supplemental dosing is required after hemodialysis sessions
- The timing of IVIG administration relative to dialysis is not critical from a clearance perspective
- IVIG may be conditionally recommended for patients with active GPA/MPA who cannot receive other immunomodulatory therapy 1
Important Safety Considerations
IVIG can cause acute renal failure, particularly in patients with pre-existing renal impairment 2, 3:
- Risk factors include baseline renal insufficiency, diabetes mellitus, older age, and high sucrose/glucose content in IVIG preparations 2
- Osmotic-induced tubular injury is the primary mechanism of IVIG-induced nephropathy 3
- Serum creatinine elevation typically occurs 1-10 days after IVIG infusion 3
- Most cases are reversible with discontinuation, though dialysis may be required temporarily 2
Dialyzer Membrane Characteristics
Standard hollow-fiber dialyzers remove solutes based on molecular weight and membrane permeability 4:
- Small molecules (<500 Da) are readily cleared
- Middle molecules (500-15,000 Da) have variable clearance depending on membrane type
- Large molecules like immunoglobulins (>100 kDa) are not significantly removed by conventional dialysis membranes 4
Clinical Pitfalls to Avoid
- Do not reduce IVIG doses in dialysis patients based on concerns about drug accumulation—standard dosing applies
- Do not assume IVIG is safe in patients with pre-existing renal insufficiency; monitor renal function closely before and after administration 2, 3
- Do not use high-osmolality IVIG preparations in patients with compromised renal function when lower-osmolality alternatives are available 3