History
A 25-year-old Caucasian man visited his GP complaining of pain in his lower back and passing red blood in his urine. He had no dysuria or fever. He is generally fit and well, working as a mechanic. He takes no regular medications and has no significant medical history. He does not smoke or drink alcohol. There is no family history of relevance. His only other complaint was of cold-like (coryzal) symptoms for the past few days.
Examination
There were no significant findings by the GP. His blood pressure was 125/65 mmHg. A urine dipstick in the surgery did demonstrate haematuria and trace protein. In view of his symptoms of flank pain and haematuria he was admitted to hospital under the urology team. He underwent a CT scan of his kidneys, ureters and bladder, which did not identify a cause. He was observed for two days as an inpatient; his flank pain settled with anal-gesia, with improvement in the haematuria.
INVESTIGATIONS
Normal range
White cells 5.0 4–11 ¥ 109/L
Haemoglobin 15.0 13–18 g/dL
Platelets 250 150–400 ¥ 109/L
Sodium 138 135–145 mmol/L
Potassium 4.0 3.5–5.0 mmol/L
Urea 6.5 3.0–7.0 mmol/L
Creatinine 75 60–110 mmol/L
Urine microscopy:
Numerous red blood cells, no red cell casts, no organisms seen
Questions:
• What is the most likely diagnosis?
• What are the potential immediate problems that might occur, and how would you manage them?
• How should this patient be followed up?
The key findings here are frank haematuria and flank pain. There was no previous history of illness or dysuria, or systemic features. Of note, he appears to have had a recent upper respiratory tract infection. Initial investigation of his urine confirmed haematuria but no infection. No obvious lesion was identified on CT imaging. His observations and blood chemistry were also normal. His condition remained stable and resolved.
The most likely diagnosis with his presenting features is IgA nephropathy. Other dif-ferentials to consider are post-streptococcal glomerulonephritis and Henoch–Schönlein purpura.
IgA nephropathy is the most common glomerular disease worldwide. It occurs most commonly in those of Asian or Caucasian origin and is more common in males (2:1).
Most cases occur between the ages of 20 and 30. Most cases are sporadic and the cause is not identified, but it tends to occur following an upper respiratory tract infection or gastrointestinal infection.
IgA nephropathy is caused by the deposition of IgA in the glomerular mesangium.
Sometimes IgG and complement can also deposit on the mesangium and this is associ-ated with more severe disease. Diagnosis can only be confirmed by renal biopsy and microscopy.
Cases can present in several ways. About half of all cases present as in this case with frank haematuria and flank pain after an upper respiratory tract infection. A third of patients can present with asymptomatic microscopic haematuria. Ten per cent of patients can present with a more severe process characterized by either the nephrotic syndrome or an acute rapidly progressive glomerulonephritis (oedema, hypertension, haematuria and renal failure).
In this case his symptoms were limited and transient. No complicating features were noted. Systemic features are common and include fever, malaise and myalgia.
A urine dipstick test for proteinuria should be performed to identify cases of nephrotic syndrome or acute rapidly progressive glomerulonephritis. Blood pressure should also be checked as a potential presentation is malignant hypertension.
A full renal profile should be checked to rule out renal failure (raised creatinine and urea, hyperkalaemia, metabolic acidosis). Other blood/serological tests should be performed to rule out other causes of glomerular disease, including complement C3 and C4, anti-GBM (glomerular basement membrane), ANCA (antinuclear cytoplasmic antibodies), ANA (antinuclear antibodies), hepatitis virology and HIV.
If the course of the illness is progressive or severe (e.g. renal failure or persistent hae-maturia/proteinuria) a renal biopsy is required. Findings to support a diagnosis are mesangial deposition of IgA with or without C3.
Cases of persistent proteinuria (with or without hypertension) should be treated with an angiotensin-converting enzyme (ACE) inhibitor or an angiotensin receptor blocker (ARB).
These drugs reduce the amount of proteinuria but their role in preventing renal dysfunc-tion is not established.
If a renal biopsy shows changes in keeping with active inflammation, or there is persist-ent haematuria, there is a role for corticosteroids. A prolonged course (6–12 months or more) may be required.
139 With more severe disease on biopsy and rapid deterioration in renal function, combined immunosuppressive therapy is indicated (e.g. prednisolone with cyclophosphamide or azathioprine). In crescentic glomerulonephritis, pulsed intravenous methylprednisolone followed by oral prednisolone and cyclophosphamide is used. Plasmapheresis is another alternative but its use is not commonplace. In some cases of acute renal failure, renal replacement therapy may have to be instituted.
The patient in this case should undergo specialist follow-up. Urinalysis, renal function and blood pressure should be checked six-monthly. As his case is mild and self-resolved he does not need long-term follow-up unless there is recurrence with or without progres-sive symptoms and signs, development of renal failure or hypertension.
KEY POINTS
• IgA nephropathy is the most common glomerular disease worldwide.
• It can present asymptomatically or with acute renal failure, haematuria, hypertension and oedema.
• Definitive diagnosis is by renal biopsy, but most cases do not require this unless there is significant proteinuria, persistent haematuria or renal impairment.
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