Renal medicine for MRCP Part 1

A 24-year-old man notices his urine turned visibly red a day after the onset of a sore throat. This has happened before with colds. Urinalysis shows blood and protein with red-cell casts, and his creatinine is mildly raised. Complement levels are normal. What is the most likely diagnosis?

1. Glomerulonephritis correct Correct. Visible haematuria within a day of a sore throat with red-cell casts is IgA nephropathy, a glomerulonephritis.
2. Renal or bladder malignancy Painless visible haematuria from a tumour. Visible haematuria concurrent with a sore throat and red-cell casts, normal complement raises it.
3. Interstitial nephritis Renal impairment from a drug or immune cause. Visible haematuria concurrent with a sore throat and red-cell casts, normal complement makes it a consideration.
4. Benign causes of haematuria Such as vigorous exercise. Visible haematuria concurrent with a sore throat and red-cell casts, normal complement redirects it.
5. Urinary tract infection Dysuria and haematuria from infection. Visible haematuria concurrent with a sore throat and red-cell casts, normal complement separates it.

The point: Glomerulonephritis is a group of conditions in which immune-mediated injury to the glomerulus causes proteinuria, haematuria and often impaired renal function. It is usefully divided into a nephritic pattern (haematuria, red-cell casts, hypertension and a variable fall in renal function) and a nephrotic pattern (heavy proteinuria over 3.5 g per day, hypoalbuminaemia and oedema). Key nephritic causes are IgA nephropathy (visible haematuria a day or two after an upper respiratory infection, the commonest primary glomerulonephritis), post-streptococcal glomerulonephritis (a week or two after a throat or skin infection, with low complement), and the rapidly progressive crescentic pattern of anti-GBM (Goodpasture) disease and ANCA-associated vasculitis. Nephrotic causes include minimal change disease (mostly in children), focal segmental glomerulosclerosis and membranous nephropathy (associated with anti-PLA2R antibodies and, in older patients, malignancy). Investigation includes urinalysis and microscopy for casts, quantification of proteinuria, renal function, complement, and an autoimmune and infection screen, with renal biopsy being the definitive test that guides treatment. Management depends on the cause: blood pressure and proteinuria control with an ACE inhibitor or angiotensin receptor blocker underpins most, immunosuppression is used for aggressive or nephrotic disease, and rapidly progressive glomerulonephritis is a nephrological emergency needing urgent immunosuppression, sometimes with plasma exchange.

Source: UK Kidney Association — clinical practice guidelines UK Kidney Association · tier 2, specialty society or college

A 24-year-old man notices his urine turned visibly red a day after the onset of a sore throat. This has happened before with colds. Urinalysis shows blood and protein with red-cell casts, and his creatinine is mildly raised. Complement levels are normal. What is the most appropriate investigation?

1. Renal function and blood pressure Assess severity. Visible haematuria concurrent with a sore throat and red-cell casts, normal complement makes them routine.
2. Complement, autoimmune and infection screen For the specific cause. Visible haematuria concurrent with a sore throat and red-cell casts, normal complement makes it targeting.
3. Quantify proteinuria and check albumin Separates nephritic from nephrotic patterns. Visible haematuria concurrent with a sore throat and red-cell casts, normal complement makes it decisive.
4. Renal biopsy Renal biopsy is the definitive test that confirms IgA nephropathy and guides treatment, and visible haematuria concurrent with a sore throat and red-cell casts, normal complement here points elsewhere.
5. Urinalysis and microscopy for red-cell casts correct Correct. Urinalysis with red-cell casts localises the bleeding to the glomerulus.

The point: Glomerulonephritis is a group of conditions in which immune-mediated injury to the glomerulus causes proteinuria, haematuria and often impaired renal function. It is usefully divided into a nephritic pattern (haematuria, red-cell casts, hypertension and a variable fall in renal function) and a nephrotic pattern (heavy proteinuria over 3.5 g per day, hypoalbuminaemia and oedema). Key nephritic causes are IgA nephropathy (visible haematuria a day or two after an upper respiratory infection, the commonest primary glomerulonephritis), post-streptococcal glomerulonephritis (a week or two after a throat or skin infection, with low complement), and the rapidly progressive crescentic pattern of anti-GBM (Goodpasture) disease and ANCA-associated vasculitis. Nephrotic causes include minimal change disease (mostly in children), focal segmental glomerulosclerosis and membranous nephropathy (associated with anti-PLA2R antibodies and, in older patients, malignancy). Investigation includes urinalysis and microscopy for casts, quantification of proteinuria, renal function, complement, and an autoimmune and infection screen, with renal biopsy being the definitive test that guides treatment. Management depends on the cause: blood pressure and proteinuria control with an ACE inhibitor or angiotensin receptor blocker underpins most, immunosuppression is used for aggressive or nephrotic disease, and rapidly progressive glomerulonephritis is a nephrological emergency needing urgent immunosuppression, sometimes with plasma exchange.

Source: UK Kidney Association — clinical practice guidelines UK Kidney Association · tier 2, specialty society or college

A 24-year-old man notices his urine turned visibly red a day after the onset of a sore throat. This has happened before with colds. Urinalysis shows blood and protein with red-cell casts, and his creatinine is mildly raised. Complement levels are normal. What is the most appropriate management?

1. Nephrology referral For diagnosis and treatment. Visible haematuria concurrent with a sore throat and red-cell casts, normal complement makes it appropriate.
2. ACE inhibitor or angiotensin receptor blocker for proteinuria and blood pressure correct Correct. An ACE inhibitor or ARB reduces proteinuria and controls blood pressure, underpinning IgA nephropathy management.
3. Immunosuppression for aggressive or nephrotic disease Guided by the biopsy. Visible haematuria concurrent with a sore throat and red-cell casts, normal complement makes it targeted.
4. Treat the underlying cause or trigger Such as an infection or malignancy. Visible haematuria concurrent with a sore throat and red-cell casts, normal complement makes it thorough.
5. Urgent immunosuppression for rapidly progressive disease A nephrological emergency. Visible haematuria concurrent with a sore throat and red-cell casts, normal complement makes it life-saving.

The point: Glomerulonephritis is a group of conditions in which immune-mediated injury to the glomerulus causes proteinuria, haematuria and often impaired renal function. It is usefully divided into a nephritic pattern (haematuria, red-cell casts, hypertension and a variable fall in renal function) and a nephrotic pattern (heavy proteinuria over 3.5 g per day, hypoalbuminaemia and oedema). Key nephritic causes are IgA nephropathy (visible haematuria a day or two after an upper respiratory infection, the commonest primary glomerulonephritis), post-streptococcal glomerulonephritis (a week or two after a throat or skin infection, with low complement), and the rapidly progressive crescentic pattern of anti-GBM (Goodpasture) disease and ANCA-associated vasculitis. Nephrotic causes include minimal change disease (mostly in children), focal segmental glomerulosclerosis and membranous nephropathy (associated with anti-PLA2R antibodies and, in older patients, malignancy). Investigation includes urinalysis and microscopy for casts, quantification of proteinuria, renal function, complement, and an autoimmune and infection screen, with renal biopsy being the definitive test that guides treatment. Management depends on the cause: blood pressure and proteinuria control with an ACE inhibitor or angiotensin receptor blocker underpins most, immunosuppression is used for aggressive or nephrotic disease, and rapidly progressive glomerulonephritis is a nephrological emergency needing urgent immunosuppression, sometimes with plasma exchange.

Source: UK Kidney Association — clinical practice guidelines UK Kidney Association · tier 2, specialty society or college