NODULAR GLOMERULOPATHY ASSOCIATED WITH NONAMYLOIDOTIC KAPPA LIGHT CHAIN DEPOSITS AND EXCESS IMMUNOGLOBULIN LIGHT CHAIN SYNTHESIS

  • 1 January 1980
    • journal article
    • research article
    • Vol. 99  (3) , 621-643
Abstract
A nodular glomerulopathy characterized by mesangial deposits of monoclonal kappa light chains was detected by immunofluorescence in a renal biopsy from a patient with proteinuria and hypertension. These nodules lacked the tinctorial and morphologic features of amyloid. Ultrastructurally, the nodules contained electron-dense granular deposits and fibrils in parallel arrangement. The fibrils measured 110-140 .ANG. in diameter. They were consistent in size with amyloid fibrils; they differed in lacking the randomly oriented network of typical amyloid fibrils and more closely resembled fibrils intrinsic to mesangial matrix. The patient had no bone marrow or X-ray evidence of myeloma and no evidence of free monoclonal light chains in serum or concentrated urines. Biosynthtic studies of the patient''s bone marrow cells demonstrated unbalanced immunoglobulin synthesis with excess production of monoclonal kappa light chains. The observed glomerulopathy probably results from direct deposition of monoclonal light chains. Deposits with kappa light chain determinants were in 7 other patients with similar nodular glomerulopathies, 4 of whom had diagnosed clinical myeloma. The lesion of nonamyloidotic nodular glomerulopathy previously described in 19 patients, not examined by immunopathologic techinques or not shown to contain light chain determinants, may have a similar pathogenesis.