glomerulonephritis

glomerulonephritis
Name	Glomerulonephritis
Synonyms	Glomerular nephritis
Caption	Diagram of a glomerulus
Field	Nephrology
Symptoms	Hematuria, Proteinuria, Edema, Hypertension
Complications	Acute kidney injury, Chronic kidney disease, Nephrotic syndrome, End-stage renal disease
Onset	Can be acute or chronic
Types	Post-streptococcal glomerulonephritis, IgA nephropathy, Lupus nephritis, Membranoproliferative glomerulonephritis
Causes	Autoimmune disorders, Infections, Vasculitis
Risks	Systemic lupus erythematosus, Diabetes mellitus, Streptococcal infection
Diagnosis	Urinalysis, Blood tests, Kidney biopsy
Differential	Interstitial nephritis, Pyelonephritis
Treatment	Corticosteroids, Immunosuppressants, Blood pressure control
Medication	Prednisone, Cyclophosphamide, Mycophenolate mofetil
Prognosis	Varies by type; can lead to Dialysis or Kidney transplantation

Glomerulonephritis is a group of kidney diseases characterized by inflammation of the glomeruli, the tiny filtering units within the nephrons. This condition can arise from a wide array of causes, including autoimmune disorders like Systemic lupus erythematosus and infections such as streptococcal pharyngitis. It is a leading cause of both Acute kidney injury and progressive Chronic kidney disease, potentially culminating in End-stage renal disease. The clinical presentation and disease course are highly variable, ranging from asymptomatic Hematuria to rapidly progressive Renal failure.

Definition and Classification

Glomerulonephritis is defined by pathological injury to the glomerular tuft, primarily driven by immune-mediated mechanisms. It is classified based on clinical presentation, histopathological findings on Kidney biopsy, and underlying etiology. Major clinical syndromes include Acute nephritic syndrome, Rapidly progressive glomerulonephritis, Nephrotic syndrome, and Chronic glomerulonephritis. Key pathological classifications, as defined by the World Health Organization and the Renal Pathology Society, encompass IgA nephropathy, Membranous nephropathy, Focal segmental glomerulosclerosis, and Membranoproliferative glomerulonephritis. Specific forms are also associated with systemic diseases such as Lupus nephritis in Systemic lupus erythematosus and Anti-GBM disease linked to Goodpasture syndrome.

Signs and Symptoms

Clinical manifestations depend on the syndrome and severity. Acute nephritic syndrome typically presents with the sudden onset of Hematuria (often cola-colored), Proteinuria, Edema (particularly periorbital), Hypertension, and Oliguria. Nephrotic syndrome is characterized by severe Proteinuria, Hypoalbuminemia, generalized Edema (Anasarca), and Hyperlipidemia. Patients with Rapidly progressive glomerulonephritis may experience a rapid decline in Glomerular filtration rate over days to weeks. Non-specific symptoms can include Fatigue, Nausea, and Loss of appetite. Chronic forms may be initially silent, presenting later with complications of Chronic kidney disease like Anemia or findings of Azotemia.

Causes and Pathophysiology

The pathogenesis most commonly involves the deposition of immune complexes within the glomerular basement membrane or the formation of autoantibodies against glomerular components. This can be triggered by infections (e.g., Post-streptococcal glomerulonephritis from Streptococcus pyogenes, or Bacterial endocarditis), systemic autoimmune diseases (e.g., Systemic lupus erythematosus, ANCA-associated vasculitis like Granulomatosis with polyangiitis), or primary renal disorders like IgA nephropathy. Other mechanisms include complement dysregulation, as seen in C3 glomerulopathy, and hereditary conditions such as Alport syndrome. The inflammatory response leads to cellular proliferation, leukocyte infiltration, and eventual scarring.

Diagnosis

Diagnosis integrates clinical evaluation, laboratory studies, and histopathology. Initial testing always includes Urinalysis to detect Hematuria, Proteinuria, and red blood cell casts, which are hallmark findings. Serological tests are crucial and may assess ANA for Lupus nephritis, ANCA for Vasculitis, anti-GBM antibodies, and complement levels (C3 and C4). Kidney biopsy remains the definitive diagnostic tool, examined by Light microscopy, Immunofluorescence, and Electron microscopy to characterize the pattern of injury. Imaging with Renal ultrasonography is used to assess kidney size and morphology.

Treatment and Management

Management is tailored to the specific etiology and disease severity. For Post-streptococcal glomerulonephritis, treatment is typically supportive, focusing on blood pressure control with agents like ACE inhibitors and management of Edema. For immune-mediated forms, Immunosuppressive therapy is cornerstone, often starting with high-dose corticosteroids like Prednisone. More aggressive regimens may include Cyclophosphamide, Mycophenolate mofetil, or Rituximab, particularly for Lupus nephritis or ANCA-associated vasculitis. In Anti-GBM disease, Plasmapheresis is urgently employed. All patients require meticulous management of Hypertension, Proteinuria, and complications of Chronic kidney disease, with progression to Dialysis or Kidney transplantation for End-stage renal disease.

Prognosis

The prognosis is highly variable and depends on the underlying pathology, severity at presentation, and response to therapy. Conditions like Post-streptococcal glomerulonephritis in children often have an excellent prognosis with full recovery. In contrast, Rapidly progressive glomerulonephritis can lead to permanent Renal failure within months if not treated aggressively. Chronic forms such as IgA nephropathy or Focal segmental glomerulosclerosis frequently follow a slowly progressive course toward End-stage renal disease over decades. Long-term outcomes are significantly influenced by the degree of Proteinuria, Hypertension, and Interstitial fibrosis on biopsy. Regular follow-up with a Nephrologist is essential for monitoring Glomerular filtration rate and managing complications.

Category:Nephrology Category:Autoimmune diseases Category:Inflammations