ULTRASTRUCTURAL-CHANGES IN THE GLOMERULAR BASEMENT-MEMBRANE OF PATIENTS WITH LAURENCE-MOON-BIEDL-BARDET SYNDROME

  • 1 January 1981
    • journal article
    • research article
    • Vol. 16  (6) , 283-288
Abstract
Renal disease, although not a cardinal feature of the Laurence-Moon-Biedl-Bardet syndrome (LMBBS), occurs in > 70% of patients and is an important cause of morbidity and mortality. Renal ultrastructural changes have not been well delineated. Glomeruli from 3 patients were studied with LMBBS, and similar ultrastructural changes were found in glomerular basement membrane (GBM). Decreased renal function, hypertension and markedly abnormal i.v. urograms with reduced concentration of dye and abnormal pelvicalyceal systems was found in 2 patients; renal function and minimal distortion of the pelvicalyceal system of 1 kidney was found in 1 patient. Light microscopy revealed varying degrees of increase in mesangial cellularity and matrix. These changes involved almost all glomeruli and were segmental. The abnormalities ranged from mild mesangial cell proliferation to complete sclerosis of the glomerular tuft. Ultrastructural study revealed marked alterations of the glomerular basement membrane: effacement of the trilaminar architecture, segmental and irregular thickening alternating with thinning and rarefaction, accumulation of granular and fibrillary material within the inner 3rd of the GBM. These ultrastructural changes may be the earliest and primary glomerular abnormality seen in LMBBS because they were seen in a patient who had minimal changes on light microscopy.