Clinicopathological characteristics of renal light chain deposition disease coexisted with cast nephropathy / 中华肾脏病杂志

ABSTRACT

Objective To investigate the clinicopathological characteristics of renal light chain deposition disease coexisted with cast nephropathy (LCDD&LCN).Methods Patients with LCDD&LCN (n=10),isolated LCDD (I-LCDD,n=21) and isolated LCN(I-LCN,n=17) diagnosed byrenal biopsy in Peking University First Hospital from January 1,2000 to March 31,2018 were enrolled,and all cases were examined by light microscopy,immunofluorescence (IF) (including light chain) and electron microscopy (EM).The semi-quantitative evaluation of the main features of renal pathology was performed.The clinical manifestations and pathological features were reviewed and compared.Results LCDD&LCN was more prevalent in middle-aged males.Nine patients showed acute renal insufficiency with small molecular proteinuria (97.1％) and microscopic hematuria.The hematologic diseases included 9 patients of multiple myeloma.The type of monoclonal light chain in serum and urine by immunofixation electrophoresis showed λ dominant (5/8).By light microscopy,glomerular lesions presented with mild mesangial proliferation in most patients,and only one of them displayed mesangial nodular sclerosis.At the same time,acute tubular injury with light chain casts was the prominent feature,and the clinical manifestations and histological features of LCDD&LCN were similar to that of I-LCN.IF revealed linear staining of monoclonal light chain along the glomerular basement membrane (GBM),tubular basement membrane (TBM) and Bowman's capsule,and also positive in tubular casts.By electron microscopy,diffuse powder-like or granular electron-dense deposits located in the inner side of the GBM,the outer layer of the TBM,renal interstitium and arteriolar walls were observed.Conclusions Patients with LCDD&LCN manifest as acute renal insufficiency,and the majority have multiple myeloma.The pathology of LCDD&LCN possesses the features of both I-LCDD and I-LCN.The IF stain of light chains(κ,λ) and ultrastructural examination by electron microscopy are the inevitable methods for the diagnosis of LCDD&LCN.