- MCNS is responsible for about 90% of cases of nephrotic syndrome in children under 5, and for ~20% of cases in adulthood.
- In children, because the large majority of patients with nephrotic sydrome have MCNS- this is assumed to be the diagnosis until proven otherwise (in adults, renal biopsy is required)
- Named because the only abnormality which can be detected is fusion/deformity of the foot process (podocytes) under the electron microscope (both light microscopy and immunofluorescence appear relatively normal)
- Unknown aetiology- presumed to be immune-mediated (thought to be T-cell (Th2) lymphocyte involvement)
- On electron microscopy, there is effacement of the epithelial cell foot processes over the outer surface of the glomerular basement membrane
- Nephrotic syndrome– investigate as appropriate
- In children, there may be a severe hypoalbuminaemia (<10g/l not uncommon)
- Haematuria and hypertension (nephritic sydrome) are rare, as is renal failure/acute kidney injury, however they can occur
- Children, in particular, are prone to infections e.g. cellulitis and pneumococcal peritonitis
- Corticosteroids are usually first line (prednisolone 60mg/day (or 1g/kg/day) for 6 weeks)
- Immunosuppressive agents (e.g. ciclosporin) can be used in patients who do not respond or who frequently relapse
- Long-term immunomodulation (with steroids or immunosuppression) can be used in frequent relapsers.