Nephritic syndrome is a collection of symptoms and signs associated with inflammatory glomerular disorders. An inflammatory response within the glomeruli results in glomerular basement membrane disruption. This leads to renal excretion of red blood cells and reduced glomerular filtration rate (GFR), which produces haematuria and raised renin (increasing blood pressure and producing oedema).
It is important to note that the term nephritic syndrome refers to a presentation of disease rather than being a disease itself. It is generally associated with the development of glomerulonephritis.
Glomerular diseases can present with features of both nephrotic and nephritic syndrome; both syndromes are considered as part of a spectrum, with some diseases being more likely to present with features of one of the syndromes.
Primary renal disease
Primary renal conditions presenting primarily with nephritic syndrome features include:
- Alport syndrome
Conditions presenting with mixed nephrotic and nephritic syndrome features include:
- IgA nephropathy
- Membranoproliferative glomerulonephritis
Secondary renal disease
Secondary diseases that can present with nephritic syndrome include:
- Post-streptococcal glomerulonephritis
- Henoch-Schonlein purpura
- Goodpasture’s syndrome
- Vasculitis e.g. ANCA-positive vasculitis
- Proliferative glomerulonephritis e.g. in systemic lupus erythematosus
- Rapidly progressive glomerulonephritis
Clinical features include:
- Proteinuria (usually < 3.5 g/day)
- RBC casts in urine
- Mild to moderate oedema
- Sterile pyuria
Investigations are aimed at diagnosing the underlying cause and are the same tests performed when investigating glomerulonephritis, which are as follows.
- Urine dipstick
- Urine microscopy and culture
- Urine albumin:creatinine ratio
- Urea and electrolytes
- Full blood count
- C-reactive protein
- Complement levels
- Antistreptolysin O titre
- Renal ultrasound
- Chest x-ray
Treatment should be directed at the underlying cause of nephritic syndrome.