- Nephritis essentially means inflammation of the kidney. Nephritis may involve the glomerulus, tubule, or the interstitial renal tissue.
- When inflammation involves the glomeruli it is called glomerulonephritis.
- When kidney disease involves structures in the kidney outside the glomerulus, it is broadly referred to as tubulo-interstitial disease. This disease generally involves the tubules and/or the interstitium of the kidney and spares the glomeruli.
- When inflammation affects the area of the kidney between the nephrons (the renal interstitium) it is known as interstitial nephritis, or sometimes tubulo-interstitial nephritis.
- Nephrosis is a descriptive histopathological term for renal disease without an inflammatory component.
Renal disease can present in a number of different ways, including as:
- Nephritic syndrome (nephritis).
- Nephrotic syndrome (nephrosis).
- Acute kidney injury (acute renal failure).
- Chronic kidney disease (chronic renal failure).
- Renal pain and dysuria.
Glomerulonephritis can present with different clinical syndromes. These include nephrotic and nephritic syndrome. Glomerulonephritis is discussed in more detail in the separate article Glomerulonephritis.
Interstitial nephritis can be acute or chronic. Acute interstitial nephritis is commonly due to a drug hypersensitivity reaction and presents as sudden-onset acute renal failure. Acute interstitial nephritis is discussed in detail in the separate article Interstitial Nephritides and Nephrotoxins.
So, nephritis and nephrosis are responses to renal disease or injury. There are a number of underlying disease processes that can lead to both nephritic and nephrotic syndromes. This article gives an overview of acute nephritis and nephrosis. There are also separate articles on:
- Nephrotic Syndrome.
- Acute Kidney Injury.
- Chronic Kidney Disease (Chronic Renal Failure).
- Renal Tubular Disease.
- Goodpasture's Syndrome.
- IgA Nephropathy (Berger's Disease).
Acute nephritic syndrome
Acute nephritic syndrome is the most serious and potentially devastating form of the various renal syndromes.
The key clinical features of acute nephritic syndrome are:
- Reduced urine output.
- Fluid retention and oedema (including periorbital, pedal and pulmonary oedema).
- Proteinuria (usually <3.5 g/day).
- Uraemic symptoms (including anorexia, pruritus, lethargy, nausea).
- Deteriorating renal function.
- Post-infection with nephritogenic strains of Group A beta-haemolytic streptococcus (typically occurs in children).
- Any of the other causes of glomerulonephritis:
- Other bacterial infections - eg, typhoid, secondary syphilis, meticillin-resistant Staphylococcus aureus (MRSA) infection, pneumococcal pneumonia, infective endocarditis.
- Viral infections - eg, hepatitis B, mumps, measles, infectious mononucleosis, varicella, Coxsackievirus.
- Parasitic infections - eg, malaria, toxoplasmosis.
- Multisystem systemic diseases - eg, systemic lupus erythematosus (SLE), vasculitis, Henoch-Schönlein purpura, Goodpasture's syndrome, Wegener's granulomatosis.
- Primary glomerular diseases - eg, Berger's disease (IgA nephropathy), membranoproliferative glomerulonephritis.
- Guillain-Barré syndrome.
- Diphtheria-pertussis-tetanus vaccine
In primary care:
- Take a history - ask about onset of symptoms, uraemic symptoms, look for a clue to an underlying cause - eg, recent streptococcal infection, other infection, multisystem disease.
- Measure blood pressure.
- Assess for peripheral, periorbital and pulmonary oedema.
- Perform urine dipstick for protein and blood.
- If acute nephritic syndrome is suspected, patients should be referred to secondary care. Acute admission may be required.
In secondary care:
- Investigations are focused on assessing severity of renal injury and looking for the underlying cause - discussed in detail in the separate article Glomerulonephritis.
- Management depends on the underlying cause and is also discussed in the same article.
- This depends on the underlying cause.
- Nephritic syndrome caused by acute post-streptococcal glomerulonephritis in children is generally excellent.
The key clinical features of nephrotic syndrome are:
- Proteinuria (formerly defined as >3.5 g/day but there appears to be individual variation around this cut-off figure).
- Hypoalbuminaemia as a result of urinary protein loss (albumin levels usually in range <25-30 g/L).
- Peripheral oedema due to hypoalbuminaemia.
- Primary renal diseases
- Minimal-change glomerular disease (15%) - the most common cause in children.
- Focal segmental glomerulosclerosis (35% of nephrotic syndrome) - the most common cause of idiopathic nephrotic syndrome in adults.
- Membranous glomerular disease (33%).
- Membranoproliferative glomerulonephritis (14%).
- Secondary renal diseases
- Post-infectious causes - eg, Group A beta-haemolytic streptococci, tuberculosis, malaria, syphilis, viruses (such as varicella-zoster, hepatitis B, human immunodeficiency), infectious mononucleosis.
- Collagen vascular diseases - eg, SLE, rheumatoid arthritis, polyarteritis nodosa, Henoch-Schönlein purpura, vasculitides.
- Metabolic diseases - eg, diabetes mellitus, amyloidosis.
- Inherited disease - eg, Alport's syndrome, hereditary nephritis, sickle cell disease.
- Malignant disease - eg, multiple myeloma, leukaemia, lymphoma, carcinoma of breast/lung/colon/stomach.
- Medications - eg, non-steroidal anti-inflammatory drugs (NSAIDs), captopril, lithium, gold, diamorphine, interferon-alpha, penicillamine, probenecid and many others.
- Toxins - eg, bee sting, snake bites, phytotoxins.
- Pregnancy - eg, pre-eclampsia.
- Transplant rejection.
In primary care:
- Take a history - onset of symptoms may be gradual over a few weeks; look for a clue to the underlying cause; some patients describe their urine as frothy; there may be associated lethargy and anorexia.
- Measure blood pressure (although hypertension is not usually found).
- Assess for peripheral, periorbital and pulmonary oedema and ascites.
- Look for deep vein thrombosis, which can occur due to a hypercoagulable state. Similarly, be wary of chest pain, which can be a symptom of pulmonary embolus.
- Perform urinalysis which will show gross proteinuria.
- If nephrotic syndrome is suspected, patients should be referred to secondary care. However, most do not require acute admission.
- The separate article Nephrotic Syndrome discusses investigations and management in more detail.
Further reading & references
- Jaipaul N; Overview of Tubulointerstitial Diseases, Merck Manual, 2009
- Alper Jr AB; Tubulointerstitial Nephritis, Medscape, Jun 2011
- Praga M, Gonzalez E; Acute interstitial nephritis. Kidney Int. 2010 Jun;77(11):956-61. doi: 10.1038/ki.2010.89. Epub 2010 Mar 24.
- McMillan J; Nephritic Syndrome, Merck Manual, 2010
- Parmar MS, Acute Glomerulonephritis, Medscape, Jun 2011
- de Seigneux S, Martin PY; Management of patients with nephrotic syndrome. Swiss Med Wkly. 2009 Jul 25;139(29-30):416-22. doi: smw-12477.
- Cohen EP et al; Nephrotic Syndrome, Medscape, Sep 2011
- Yang GF, Schoepf UJ, Zhu H, et al; Thromboembolic complications in nephrotic syndrome: imaging spectrum. Acta Radiol. 2012 Oct 18.
|Original Author: Dr Michelle Wright||Current Version: Dr Laurence Knott||Peer Reviewer: Dr Helen Huins|
|Last Checked: 25/01/2013||Document ID: 1763 Version: 22||© EMIS|
Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. EMIS has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.