Clinical and pathological analysis of patients presenting renal lesion and monoclonal gammopathy / 中华肾脏病杂志

ABSTRACT

Objectives To analyze the spectrum of renal diseases associated with monoclonal gammopathy and unrelated renal diseases.Methods Hospitalized patients in Peking Union Medical College Hospital who underwent renal biopsy between January,2013 and December,2015.They had monoclonal gammopathy on serum protein electrophoresis (SPE),serum immunofixation electrophoresis (IFE),urine IFE and/or serum free light chain (FLC).64 patients met the inclusion criteria and were classified as monoclonal gammopathy of renal significance (MGRS) (n=36),monoclonal gammopathy of undetermined significance (MGUS) (n=17) and hematologic malignancy (n=11).Results Renal lesions in MGRS subgroup included light chain amyloidosis (n=28,77.8％),light chain deposition disease (n=7,19.4％),and fibrillary glomerulopathy (n=l,2.8％).eGFR in light chain amyloidosis subgroup differed significantly,compared with light chain deposition disease [eGFR 93 ml· min-1 · (1.73m2)-1 vs 28 ml· min-1 · (1.73 m2) 1,P ＜ 0.01],as well as HTN incidence (35.7％ vs 100.0％,P ＜ 0.01).Renal diseases in MGUS subgroup included membranous nephropathy (n=10,58.8％),focal segmental glomerulosclerosis (n=3,17.6％),diabetic glomerulopathy (n=l,5.9％),Henoch-Schonlein purpura nephritis (n=l,5.9％),anti-glomerular basement membrane disease concurrent with membranous nephropathy (n=l,5.9％) and glomerulomegaly (n=l,5.9％).Various renal lesions related/unrelated to hematologic malignancy were seen in third subgroup,including light chain cast nephropathy (n=3,27.3％),tubulo-interstitial lesions (n=2,18.2％),light chain amyloidosis (n=1,9.1％),light chain deposition disease(n=1,9.1％),IgA nephropathy (n=1,9.1％),mesangial proliferative glomerulonephritis (n=l,9.1％),endocapillary proliferative glomerulonephritis (n=1,9.1％) and acute tubular necrosis (n=1,9.1％).Positive rates of SPE,serun IFE and urine IFE in MGRS subgroup were 40.6％,52.8％ and 69.4％,respectively.Positive rates of SPE,serum IFE and urine IFE in MGUS subgroup were 68.8％,100.0％ and 37.5％,respectively.Positive rates of SPE,serum IFE and urine IFE in hematologic malignancy subgroup were 54.5％,72.7％ and 81.8％ respectively.MGRS and MGUS subgroups differed significantly in positive rate of serum IFE (P ＜ 0.001).Abnormal rates of serum FLC ratio in above three subgroups were 83.3％,17.6％ and 90.9％,respectively,with that in MGUS group being significantly lower than the rates in other two groups (P ＜ 0.001,respectively).Conclusions The significance of monoclonal gammopathy in patients with renal disease should be evaluated by other clinical data,as well as renal pathology.