GlomerulonephritidesN05.9

Glomerulonephritis" is a series of immune-mediated, bilateral inflammatory diseases of the kidneys in which the glomerules are affected first and which cause cellular proliferation with possible consecutive restriction of renal function.

The classification of glomerulonephritides is not uniform, as they can be classified on the basis of their origin, their acute nature, their histopathologic substrates, and their clinical form. Thus, they can be classified according to different criteria.

Classification according to pathogenesis:

• Primary GN: various forms of autoimmunologically induced glomerulonephritides primarily occurring in the glomeruli (glomerulopathies) without demonstrable signs of systemic disease.
• Secondary glomerulonephritides GN: Renal involvement in various systemic diseases: such as infection in postinfectious glomerulonephritis, in autoimmune diseases such as Goodpasture's syndrome, granulomatosis with polyangiitis, SLE, in drugs such as gold or penicillamine.

Classification by etiopathogenesis:

• postinfectious
• in genetic disorders (Familial FSGS; Congenital nephrotic syndrome; Steroid resistant nephrotic syndrome, Charcot-Marie-Tooth disease and others)
• In autoimmune diseases.

Classification according to clinical course:

Glomerulonephritis can have two courses:

• Acute: It develops over a short period of time.
• Chronic: It develops over a long period of time.

In about 1% of affected children and 10% of affected adults, acute glomerulonephritis develops into rapidly progressive glomerulonephritis in which most glomeruli are destroyed. This leads to renal failure.

Acute glomerulonephritis

• IgA nephropathy (Berger's disease)
• Thin basement membrane type nephropathy (benign hematuria).
• Alport syndrome (hereditary nephritis)
• Acute postinfectious (infection-associated) glomerulonephritis
• Rapid Progressive Glomerulonephritis (RPGN)
  • RPGN type I: Anti-GBM RPGN
  • RPGN type II: immune complex -RPGN
  • RPGN type III: ANCA-associated RPGN

Primary glomerulonephritis with nephrotic syndrome

• Minimal change glomerulonephritis (MCD)
• Focal segmental sclerosing glomerulonephritis (Focal segmental glomerulosclerosis - FSGS)
  • Primary (idiopathic form)
  • Familial or genetic form
  • Congenital nephrotic syndrome
  • Steroid-resistant nephrotic syndrome
  • Familial FSGS
  • Charcot-Marie-Tooth syndrome
• Membranous glomerulonephritis
• Membranoproliferative glomerulonephritis
• C3 glomerulopathy

Glomerular involvement in metabolic diseases

Degenerative glomerular diseases (sclerosis, fibrosis)

About 50% of people suffering from acute glomerulonephritis do not have any symptoms. Glomerulonephritis becomes symptomatic by edema (eyelid swelling, facial swelling, peripheral edema), reduction in the amount of urine, hematuria, varying degrees of proteinnuria. If renal function is impaired, there is an increase in blood pressure (regulation of blood pressure via the renin-angiotensin-aldosterone system). Some people experience drowsiness and confusion. In the elderly, nonspecific symptoms such as nausea and a general feeling of illness are often observed.

When rapidly progressive glomerulonephritis develops, weakness, fatigue, and fever are the most common early symptoms; so are nausea, loss of appetite, vomiting, joint and abdominal pain. Flu-like symptoms often precede the nephrologic abnormalities.

Because chronic glomerulonephritis usually produces only very mild or subtle symptoms, it goes undetected in most sufferers. Edema may develop. Hypertension is common. This disease can progress to renal failure, which in turn can cause itching, fatigue, loss of appetite, nausea, vomiting, and difficulty breathing.

Corresponding basic nephrological diagnostics with laboratory, urine tests, kidney biopsy, imaging diagnostic procedures of the kidneys such as ultrasound or CT. The kidney biopsy is the safest method for the diagnostic classification (and targeted therapy or assessment of the prognosis) of glomerulonephritis.

Treatment of the underlying disease (see there).