Nephritis refers to inflammation within the nephrons of the kidneys. It causes:
- Reduction in kidney function
- Haematuria: invisible or visible amounts of blood in the urine
- Proteinuria: although less than in nephrotic syndrome
The two most common causes of nephritis in children are post-streptococcal glomerulonephritis and IgA nephropathy (Berger’s disease).
Post-streptococcal glomerulonephritis occurs 1 – 3 weeks after a β-haemolytic streptococcus infection, such as tonsillitis caused by Streptococcus pyogenes. Immune complexes made up of streptococcal antigens, antibodies and complement proteins get stuck in the glomeruli of the kidney and cause inflammation. This inflammation leads to an acute deterioration in renal function, causing an acute kidney injury.
Consider a diagnosis of post-streptococcal glomerulonephritis where there is evidence of recent tonsillitis caused by streptococcus. This could be a history of tonsillitis, positive throat swab results and anti-streptolysin antibody titres found on a blood test.
Management is supportive and around 80% of patients will make a full recovery. In some cases patients can develop a progressive worsening of their renal function. They may need treatment with antihypertensive medications and diuretics if they develop complications such as hypertension and oedema.
IgA nephropathy is also known as Berger’s disease. This condition is related to Henoch-Schonlein Purpura, which is an IgA vasculitis. IgA deposits in the nephrons of the kidney causes inflammation (nephritis). When a renal biopsy is taken the histology will show “IgA deposits and glomerular mesangial proliferation”.
It usually presents in teenagers or young adults.
Management involves supportive treatment of the renal failure and immunosuppressant medications such as steroids and cyclophosphamide to slow the progression of the disease.
Last updated August 2019