Light-chain nephropathy

The authors deal with the clinicopathology of the renal, alterations in light-chain disease in connection with 6 cases. The disease was recognized by the monotype (in 5 cases kappa, in 1 case lambda) immunoreactivity of the light-chain paraprotein deposited in the basal membranes of the renal tissue. Electron microscopic examinations proved the fine-granulated, electrodense character of the paraprotein. Multiple myeloma was found in 3 cases and plasma cell dyscrasia of non-tumorous characteristic in 3 cases in the background of the deposition. The renal involvement appeared clinically in the picture of proteinuria without nephrosis syndrome and in progressing azotemia. Chronic renal insufficiency developed during some months in 5 patients. Morphologically renal impairment manifested in interstitial fibrosis, tubular atrophy and ateriolar hyalinosis was seen. These were associated with different glomerular alterations, for instance in 3 cases with nodular glomerulosclerosis. In 1 patient with plasma cell dyscrasia of non-tumorous characteristic nodular glomerulosclerosis and semilunar formation was observed in 56% of the glomeruli. In an other patient with myeloma the simultaneous existence of cylinder nephropathy and light-chain nephropathy was demonstrated. Both observations are unusual phenomena in plasma cell dyscrasia.