Renal amyloidosis prediction in kidney disease patients accompanied by monoclonal gammopathy

Summary This study aimed to assess whether routine nephrology examinations could predict renal amyloidosis in kidney disease patients with monoclonal gammopathy. A total of 356 consecutive hospitalized patients in the nephrology department with monoclonal gammopathy performed renal biopsies, including 50 renal amyloidosis patients and 306 non‐renal amyloidosis patients, were included after strict filtering. Laboratory and imaging data were collected for each patient. Renal amyloidosis patients exhibited significantly higher 24‐h proteinuria and estimated glomerular filtration rate and decreased serum creatinine (SCr), albumin and immunoglobin M, with lower κ light chain and κ / λ ratio in urine and serum. Higher 24‐h proteinuria and 24‐h microalbuminuria and lower random urine κ / λ ratio, serum κ light chain, serum κ / λ ratio and SCr were significant risk factors for renal amyloidosis. Nomogram model identified albumin, 24‐h urinary microalbumin excretion rate, 24‐h urine κ light chain, 24‐h urine κ / λ ratio and serum IgM as combined predictors of renal amyloidosis (area under the curve 0.781, 95% CI 0.718–0.854). Combined biomarkers (albumin, 24‐h urinary microalbumin excretion rate, 24 h urine κ light chain, 24‐h urine κ / λ ratio and serum IgM) effectively predicted renal amyloidosis in kidney disease patients with monoclonal gammopathy.