Acute nephritic syndrome and glomerulonephritis — branching viva

Stem 1 — Six-year-old with cola-coloured urine (5 minutes)

A six-year-old boy presents with two days of smoky brown urine and morning periorbital puffiness. He had a sore throat two weeks ago. His blood pressure is at the 95th percentile and his urinalysis shows blood and protein with dysmorphic red cells and casts. [3] [6]

Branch A (examiner): Define the acute nephritic syndrome and name its four components. Why is this almost certainly post-streptococcal glomerulonephritis? [1] [3]

Branch B (examiner): What will his serum complement show, and by when should the C3 normalise? What follow-up blood test confirms the diagnosis, and what result would force you to change the diagnosis? [2] [11]

Branch C (examiner): Outline your supportive management. Name the eradication regimen, and explain clearly why penicillin does not reverse the glomerulonephritis itself. [3] [6]

Stem 2 — Ten-year-old whose C3 has not normalised at eight weeks (5 minutes)

A ten-year-old boy was diagnosed with post-streptococcal GN six weeks ago. His haematuria has settled, but at the eight-week follow-up his serum C3 is still low and he has persistent proteinuria. [11]

Branch A (examiner): Is this still post-streptococcal GN? What is the significance of a C3 that has not normalised by eight weeks, and what two diagnoses must you now consider? [2] [11]

Branch B (examiner): What further investigations would you arrange, and what is the role of renal biopsy here? Name the histological pattern you would look for. [1] [11]

Branch C (examiner): How does the management and prognosis of C3 glomerulopathy differ from post-streptococcal GN, and why does this distinction matter for the family? [7] [11]

Stem 3 — Seven-year-old with IgA vasculitis and nephritic urine (5 minutes)

A seven-year-old girl has a palpable purpuric rash on her legs and buttocks, abdominal pain and swollen knees. On day five her urinalysis shows blood and protein. Her serum C3 and C4 are both normal. [9] [10]

Branch A (examiner): How does the normal complement here distinguish this nephritis from post-streptococcal GN, and what defines the underlying syndrome? [9] [11]

Branch B (examiner): State the indications for renal biopsy in IgA vasculitis nephritis. If her proteinuria reaches nephrotic range and her creatinine rises, what treatment is indicated? [1] [10]

Branch C (examiner): Summarise the evidence on steroids for IgA vasculitis nephritis. Which children benefit, and which do not? [10] [12]