Nephrotic syndrome is the combination of:
- Proteinuria (>3-3.5g/24 hrs or urine protein:creatinine ratio >300-350m/mmol)
- Hypoalbuminaemia (serum albumin <25g/l)
- Peripheral oedema
There is also often severe hyperlipidaemia
Causes of nephrotic syndrome include
- Primary glomerular diseases – accounts for the majority of cases
- Focal segmental glomerulosclerosis – commonest primary cause in black paients; accounts for around a third of primary cases
- Membranous glomerular disease –commonest primary cause in white patients; also accounts for around a third of primary cases
- Minimal change disease – 15%
- Membranoproliferative glomerular disease – 14%
- Secondary causes
- Diabetes -commonest secondary cause
- Amyloidosis
- SLE
- Myeloma
- Lymphoma
- Drugs (NSAIDs, penicillamine, captopril, lithium, tamoxifen)
- Infections (HIV, mycoplasma, syphilis, malaria, toxoplasmosis, schistosomiasis)
- Congenital causes ( Alport’s syndrome, Nail-patella syndrome)
Presentation of nephrotic syndrome includes
- Oedema
- Often initially periorbital
- Tiredness
- Breathlessness
Clinical signs which may be present include:
- Oedema
- Leuconychia (due to the low albumin)
- Signs of pleural effusion
- Raised JVP
- Ascites
- Eruptive xanthomata
- Xanthalasmata
- Frothy urine
Investigations
- Urine dipstick (Protein +++, haematuria)
- Early morning urinary protein:creatinine ratio
- Bloods – UEs, LFTs, FBC, clotting
- Investigations looking for causes of nephrotic syndrome
- Glucose
- CRP
- Immunoglobulins
- ?autoimmune screen
- CXR
- Renal ultrasound
- Renal biopsy
Management
- Refer to renal team
- Fluid restrict – 1.5l
- Restrict sodium
- Furosemide
- ACE-i
- ? prophylactic anticoagulation
Complications
- Thromboembolism
- DVT
- PE
- Renal vein thrombosis
- Infection (20%)
- Acute renal failure
Small print gem: Membranous glomerular disease has an association with cancer, especially lung and bowel.
References
