Here, we provided evidence that AMG853, a bispecific antagonist targeting both PTGDRs, was effective in blocking PGD2-induced human and mouse basophil activation ex vivo and in controlling basophil recruitment to SLOs, humoral autoimmunity, IgE production, CIC glomerular deposition, and kidney inflammation in aged Lyn−/− mice with established lupus-like nephritis. The gene discussed is IGHE; the disease is nephritis.