Renal

Question 1

What is nephrotic syndrome?

Answer 1

• Massive proteinuria, with the daily loss of 3-3.5g or more of protein
• Hypoalbuminemia, with plasma albumin levels less than 3.5g/dL
• Generalized oedema
• Hyperlipidemia and lipiduria

Question 2

What are the secondary causes of nephrotic syndrome?

Answer 2

• Diabetes mellitus
• Amyloidosis
• Systemic lupus erythematosus
• Drugs (nonsteroidal anti-inflammatory, penicillamine, heroin)
• Infections (malaria, syphilis, hepatitis B and C, HIV)
• Malignant disease (carcinoma, lymphoma)

Question 3

What is minimal change disease?

Answer 3

• Cause of nephrotic syndrome
• Primary disorder of podocytes
• Immunofluorescence negative
• Mx with corticosteroids

Question 4

What is focal segmental glomerulosclerosis (FSGS)?

Answer 4

• Commonest cause of nephrotic syndrome in adults (US)
• Primary disorder of podocytes (podocytopathy)
• Sclerosis of some, but not all, glomeruli (focal)
• in the affected glomeruli, only a portion of the capillary tuft is involved (thus, it is segmental).
• focal and segmental lesions may involve only a minority of the glomeruli and may be missed. Cortico-medullary junction sampling
• Immunofluorescence negative
• Primary is idiopathic
• Secondary is HIV or adaptive
• Mx with corticosteroids

Question 5

What is membranous nephropathy?

Answer 5

•Immune mediated – antigen antibody complexes
•Diffuse process
•complement C5b–C9 membrane attack complex-
> injure glomerular epithelial and mesangial
cells, inducing them to liberate proteases and
oxidants ->capillary wall injury ->increased
protein leakage
•Primary is most common and has antigen - M-type phospholipase A2 receptor (PLA2R, on epithelial cells)
• Granular IgG deposits along glomerular capillary loops on immunofluorescence
• Low risk= conservative mx, high risk= steroids or antibodies

Question 6

What is diabetic nephropathy?

Answer 6

• Microvascular injury – glomerular capillaries
• if marked proteinuria + retinopathy most likely have diabetic nephropathy
• Light microscopy: Glomerular changes
• initial diffuse glomerulosclerosis ( mesangial matrix)
• later nodule formation (N) (Kimmelstiel-Wilson lesion)
• Mx with dapagliflozin, ACE inhibitors and statins

Question 7

What is nephritic syndrome?

Answer 7

• Hematuria (red blood cells and red cell casts in urine)
• Proteinuria (usually subnephrotic range) with or
without oedema
• Protein:Creatinine ratio <300mgm/mmol
• Uraemia
• Hypertension

Question 8

What is IgA nephropathy?

Answer 8

• Most common cause of glomerulonephritis
• IgA deposits in mesangial region
• hereditary or acquired defect in the galactose-
containing sugar chains of the IgA molecule (IgA1)
prior to their secretion by B cells.
• aberrantly glycosylated IgA – deposited in glomeruli OR forms immune complexes in the circulation with IgG autoantibodies
• Mx= ACE inhibitor/Angiotensin receptor blocker, SGLT 2 inhibitor (dapagliflozin)

Question 9

What is lupus nephritis?

Answer 9

• Systemic lupus erythematosus (SLE) is an autoimmune disease- autoantibodies against their own nuclear proteins and many other self antigens
• SLE is the prototype of a human systemic immune complex disease (type III hypersensitivity)
• Proliferative glomerulonephritis with active lesions – wire-loops, hyaline thrombi, may be crescents
• “Full-house” immunofluorescence
• Treatment – Active lupus nephritis – Rituximab and steroids/Cyclophosphamide/Mycophenolate mofetil (MMF