Membranoproliferative Glomerulonephritis

The Membranoproliferative glomerulonephritis ( MPGN, mesangiocapillary glomerulonephritis, Lobular glomerulonephritis ) is a rare disease of the renal corpuscle ( glomerulus ). The idiopathic form ( no known cause ) occurs at an age 8-30 years at most.

Symptoms

Symptoms are

• Appearance of red blood cells in the urine ( hematuria ), show the phase contrast microscopy characteristic deformations ( dysmorphic erythrocytes, acanthocytes ) and can form Eryhtrozytenzylinder.
• Detection of protein in the urine (proteinuria ), the protein excretion is usually moderate and less than 1.5 g / d
• Gradients with nephritic syndrome ( hematuria, hypertension and renal impairment ) or nephrotic syndrome (proteinuria > 3.5 g / d, water retention ( edema ) and lipid metabolism disorder ) are possible

Diagnosis

The diagnosis is made by histological (histological ) examination of a tissue sample of the kidney.

When examined in the light microscope can be found:

• Thickening of the basement membrane of the renal corpuscle, due to the deposition of immune complexes,
• The penetration of mesangial cells in the gap between the basement membrane and endothelium
• An increased cell proliferation of mesangial cells by content and migration of monocytes from the bloodstream.

Classification

Based on electron microscopic findings, three types can be distinguished:

Membranoproliferative glomerulonephritis type I

In type I immune complexes are found in the mesangium as well as the gap between endothelium and basement membrane, leading to a Doppelkonturierung the basement membrane (tram track sign, tram rail). Type I is the most common form of membranoproliferative glomerulonephritis. The disease can without obvious cause ( idiopathic) or as a result of diseases occur in which it is circulating in the formation of immune complexes which are deposited in the kidney, for example, hepatitis C, with or without cryoglobulinemia, systemic lupus erythematosus, chronic hepatitis B, subacute bacterial endocarditis and infected ventrikuloatrialer shunt.

Membranoproliferative glomerulonephritis type II (dense deposit disease)

In type II, continuous ribbon-like deposits found within the basement membrane of the renal corpuscles ( glomeruli ), renal tubules ( tubules ) and Bowmann'scher capsule of the renal corpuscle. By immunofluorescence microscopy in the complement C3 deposits, but not to detect immunoglobulin.

Membranoproliferative glomerulonephritis type III

In type III can be found as in the type I immune complex deposits between endothelium and basement membrane and a Doppelkonturierung the basement membrane. In addition, immune deposits are between basement membrane and podocytes detected ( as in the epimembranösen glomerulonephritis ).