Glomerulonephritis By Dr. Abdelaty Shawky Assistant professor of pathology
Glomerular diseases constitute one of the major problems in nephrology; indeed, chronic glomerulonephritis is one of the most common causes of chronic renal failure in humans.
* Classification of glomerular diseases: I. Primary G.N (the disease affects kidney only): • Minimal change glomerular disease (Lipoid nephrosis). • Acute diffuse proliferative G.N: • Post-streptococcal G.N. • Non-post-streptococcal GN. • Rapidly progressive G.N. • MembraneousG.N. • MembranoproliferativeG.N. • Chronic G.N.
II. Secondary G.N (the disease affects kidney and other organs): • Systemic lupus erythematosus (SLE). • Polyarteritisnodosa (PAN). • Wegener granulomatosis. • Diabetes mellitus (diabeteic nephropathy). • Goodpasture syndrome. • Amyloidosis.
Most of the 1ry glomerular disease are due to immunologic mechanisms. • To study any glomerular disease, a renal biopsy is taken and examined by 3 types of microscopes: 1. Light microscope: to examine the structure of glomeruli, tubules and interstitium. 2. IF (immune flourescentmicroscope): to detect the type of deposited immunoglobulin in the glomeruli. 3. EM (electron microscope): to detect the site of immune complex, either sub-epithelial, sub-endothelial, mesangial or basement membrane..
*Etiology & pathogenesis: • Chemical change in the glomerular basement membrane causing protein loss.
* Grossly: • Mild bilateral kidney enlargement. * LM (Light microscope): • No abnormalities. * IF (Immunoflurescence): • No immune deposits. * EM (Electron microscope): • Fusion of the foot processes of the epithelial cells (podocytes).
* CP (Clinical picture): • Affect children and young adults. • Cause nephrotic syndrome. * Fate: • The disease has excellent prognosis and most patients respond to corticosteroids with complete resolution of proteinuria.
*Etiology & pathogenesis: • Immune complex reaction; (nephrotegenic strains of group A beta haemolytic streptococci + Ig G), the complex is deposited in the glomeruli with subsequent complement activation acute inflammation.
* Grossly: • Mild bilateral kidney enlargement with petechial hemorrhages.
* LM (Light microscope): a. Glomeruli: • Proliferation of endothelial and mesangial cells. • Glomerular capillaries contain neutrophils. • Bowman’s space shows: neutrophils, RBCs, some albumin. b. Tubules: • The lining cells are swollen. • The lumens show casts (RBCs casts, neutrophil casts & hyaline casts). c. Interstitium: • Acute inflammatory reaction…...
* IF (Immunoflurescence): • Deposition of IgG and C3.
* EM (Electron microscope): • Subepithelial immune complex deposit (humps).
* CP (Clinical picture): • A young child presents with oliguria, hematuria (cocoa-colored urine) and peri-orbital edema about 2 weeks after recovery from a sore throat.
Hematuria (coca cola colored urine) RBCs cast
More than 95% of the affected children eventually recover totally with treatment. • A small minority of children (perhaps less than 1%) do not improve, become severely oliguric, and develop a rapidly progressive glomerulonephritis. • Some of the remaining patients may undergo slow progression to chronic glomerulonephritis.
Nephritic syndrome - A syndrome formed of: 1. Haematuria. 2. Oliguria. 3. Peri-orbital oedema. 4. Hypertension. - The most common cause of nephritic syndrome in children is post-streptococcal GN.
Nephrotic syndrome - A syndrome formed of: 1. Hypoproteinaemia. 2. Proteinuria . 3. Oedema. 4. Hypercholesterolaemia. • The most common cause of nephrotic syndrome in children is minimal change glomerular disease. • The most common cause of nephrotic syndrome in adults is membranous GN.
Thanks References: Robbins and Cotran’s: Pathologic Basis of Disease. Seventh edition.