Association between sodium content of intravenous immunoglobulin and electrolyte changes and clinical course of Kawasaki disease.

Background: Intravenous immunoglobulin (IVIG) formulations used to treat Kawasaki disease differ markedly in sodium content; however, the clinical significance of this factor remains unclear. Purpose: Here we investigated whether sodium content influences electrolyte changes and short-term clinical outcomes of Kawasaki disease. Methods: This single-center retrospective cohort study included 744 children with first-episode Kawasaki disease treated with 2-kg IVIG in 2010-2020. The patients were categorized into high-sodium (Glovenin-I or Venilon-I) and low-sodium (Venoglobulin IH) groups. Serum electrolytes, total protein, and immunoglobulin G levels were measured before and after IVIG administration. Outcomes included additional IVIG administration and the presence of coronary artery lesions. Results: Compared to the low-sodium group, the high-sodium group had significantly increased serum sodium (2.9±3.2 mEq/L vs. 1.7±2.7 mEq/L) but significantly decreased serum potassium (-0.13±0.50 mEq/L vs. -0.03±0.49 mEq/L) levels after IVIG therapy. After its administration, hyponatremia occurred more often in the low-sodium group (4.4% vs. 0.3%), whereas hypokalemia occurred more frequently in the high-sodium group (9.9% vs. 5.5%). Total protein, immunoglobulin G, and albumin levels were higher in the low-sodium group. The rates of additional IVIG use and coronary artery lesions did not differ significantly between groups. Conclusion: Our findings demonstrate that the sodium content of IVIG contributes to distinct changes in electrolyte and protein concentrations during the acute phase of Kawasaki disease. However, these biochemical differences were not associated with short-term clinical outcomes. Awareness of formulation-specific profiles may help clinicians interpret laboratory findings appropriately during IVIG therapy.