The Levels of IgG Subclasses and Vaccine-induced Viral Antibodies in Childhood Minimal Change Nephrotic Syndrome

ABSTRACT

PURPOSE: Hypogammaglobulinemia has been observed in nephrotic syndrome, but its pathophysiology remains unknown. We evaluated serum immunoglobulins, IgG subclasses, and vaccine-induced viral antibodies(anti-hepatitis B surface IgG and anti-measles IgG) in children with minimal change nephrotic syndrome(MCNS). METHODS: Using the stored sera, the levels of immunoglobulin(IgG, IgM, IgA, and IgE) and IgG subclasses(IgG 1, 2, 3, and 4), anti-HBs Ab and anti-measles IgG of 21 children with MCNS were analyzed and compared to those of 25 age-matched healthy children. RESULTS: The mean values of IgG and IgG1 were 390+/-187 mg/dL and 287+/-120 mg/dL in nephrotic children, and 1,025+/-284 mg/dL and 785+/-19 mg/dL in control children, respectively. The values of the total IgG and the 4 IgG subclasses in nephrotic children were all significantly depressed(P<0.001), but the IgM(251+/-183 mg/dL vs. 153+/-55 mg/dL, P=0.02) and IgE values(P=0.01) were elevated, and the IgA values were not changed. The seropositivity of anti-HBs IgG was 42.9%(9 of 21 cases) in the MCNS group and 52%(13/25) in the control group, and that of anti-measles IgG was 76%(16/21) and 92%(23/25), respectively, but there was no statistical difference between the two groups. CONCLUSION: IgG and IgG subclass levels in MCNS children are all depressed without significant seronegativity of the vaccine-induced viral antibodies. Further studies are needed to resolve the cause of hypogammaglobulinemia in MCNS.