Hemoglobinuria and acute kidney injury requiring hemodialysis following intravenous immunoglobulin infusion.

Intravenous immunoglobulin (IVIG), a product initially developed for patients with immunodeficiencies, now has multiple other indications and increasing off-label use. IVIG generally is well tolerated, with few adverse effects. Antibody-mediated (Coombs-positive) hemolysis is known to occur after IVIG infusion, but often is subclinical and previously has not been reported to lead to acute kidney injury (AKI). The predominantly known mechanism of AKI after IVIG infusion has been osmotic nephrosis, primarily associated with sucrose-containing formulations. We present a case of a bone marrow transplant recipient who was treated with a sucrose-free IVIG product and subsequently developed Coombs-positive hemolysis leading to AKI requiring hemodialysis, who ultimately died secondary to infectious complications. The severity of this case emphasizes the importance of identifying populations who may be at increased risk of pigment-mediated kidney injury before consideration of IVIG therapy.

Contribution of residual function to removal of protein-bound solutes in hemodialysis.

BACKGROUND AND OBJECTIVES: This study evaluated the contribution of residual function to the removal of solutes for which protein binding limits clearance by hemdialysis. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Solute concentrations were measured in 25 hemodialysis patients with residual urea clearances ranging from 0.1 to 6.2 ml/min per 1.73 m2. Mathematical modeling assessed the effect of residual function on time-averaged solute concentrations. RESULTS: Dialytic clearances of the protein-bound solutes p-cresol sulfate, indoxyl sulfate, and hippurate were reduced in proportion to the avidity of binding and averaged 8±2, 10±3, and 44±13% of the dialytic urea clearance. For each bound solute, the residual clearance was larger in relation to the residual urea clearance. Residual kidney function therefore removed a larger portion of each of the bound solutes than of urea. Increasing residual function was associated with lower plasma levels of p-cresol sulfate and hippurate but not indoxyl sulfate. Wide variation in solute generation tended to obscure the dependence of plasma solute levels on residual function. Mathematical modeling that corrected for this variation indicated that increasing residual function will reduce the plasma level of each of the bound solutes more than the plasma level of urea. CONCLUSIONS: In comparison to urea, solutes than bind to plasma proteins can be more effectively cleared by residual function than by hemodialysis. Levels of such solutes will be lower in patients with residual function than in patients without residual function even if the dialysis dose is reduced based on measurement of residual urea clearance in accord with current guidelines.