Impact of response on progression of renal damage and challenging electrophoretic pattern in light chain deposition disease. (A) Mean annual change in estimated glomerular filtration rate (eGFR) in patients attaining a VGPR or CR, compared with patients reaching less than VGPR. Only 14% of patients in VGPR or CR required dialysis, compared with 64% of other subjects. (B) The serum electrophoresis scan (top) and anti-κ immunofixation (bottom) show no monoclonal immunoglobulin in a patient with LCDD and with a serum κ free LC (FLC) concentration of 609 mg/L and a greatly abnormal FLC ratio. In our population of 68 patients with LCDD, a monoclonal protein was detected by serum and urine electrophoresis/immunofixation in only 60% of the patients, whereas FLC concentration and ratio were abnormal in all. S, serum; U, urine.