The cytokine and IgM levels in the sera or culture supernatants, and the levels of serum IgG anti-dsDNA Abs were measured using ELISA kits (IL-4 and IFN-γ: BD Biosciences, San Diego, CA; IgM: Bethyl Laboratories, Inc., Montgomery, TX; IgG anti-dsDNA Abs: Shibayagi Co. Ltd., Gunma, Japan). BUN levels and serum albumin, total protein, and alanine aminotransferase levels were measured using a DRICHEM 3000 V system (Fuji Medical System, Tokyo, Japan). Urinary protein excretion was measured by a clinical laboratory testing company (SRL, Tokyo, Japan).