[Morphological characteristics of the non-amyloid form of renal monoclonal immunoglobulin deposition].

The paper shows the morphological findings of and clinical and demographic data on 61 patients with nonamyloid form of renal monoclonal immunoglobulin deposition disease (MIDD) unassociated with amyloidosis and/or Bence-Jones nephropathy: 40 cases of light-chain deposition disease, 18 cases of light-and-heavy- chain deposition disease (LHCDD) and 3 cases of heavy-chain deposition disease (HCDD). According to the composition of paraprotein deposits, the cases were distributed as follows: k (30), lambda (10), IgG/k (6), IgA/k (6), IgG/lambda (4), IgA/lambda (2), and IgA/gamma (3). Light microscopy revealed three variants of the glomerular structure: diffuse nodular glomerulopathy (42.6%), diffuse mesangeal dilation (27.9%), and inract glomeruli (29.5%). Varying severity of tubular atrophy was noted in 95% of cases. Tubular, glomerular, and smooth muscle basement membrane deposits substantially differed in immunofluorescent (100%, 91.8% and 54.1%) and ultrastructural studies (55.7%, 45.9%, and 4.9%, respectively). Azotemia (68.9%) and proteinuria (55.8%) were most commonly revealed. The incidence of nephrotic syndrome concurrent with severe proteinuria was 27.9%.