Nephrology for MRCP Part 2

A 58-year-old man presents with haemoptysis and acute kidney injury. Creatinine 420 micromol/L, urine dipstick shows blood and protein, and microscopy shows red cell casts. Chest radiograph shows bilateral alveolar shadowing. Anti-glomerular basement membrane antibody is strongly positive; ANCA is negative. What is the most appropriate treatment?

1. Plasma exchange with corticosteroids and cyclophosphamide correct Correct. Anti-GBM disease with pulmonary haemorrhage is an emergency. Plasma exchange removes circulating antibody, and steroids plus cyclophosphamide stop its production. Delay costs both renal recovery and life.
2. Corticosteroids alone Wrong. Immunosuppression without plasma exchange leaves the pathogenic antibody circulating and is inadequate for pulmonary haemorrhage.
3. High-dose intravenous immunoglobulin Wrong. There is no established role in anti-GBM disease, and it does not remove the antibody.
4. Rituximab monotherapy Wrong as first line here. Rituximab has an established place in ANCA-associated vasculitis, but the evidence base in anti-GBM disease does not support replacing the standard triple approach.
5. Urgent haemodialysis alone with supportive care Wrong as a strategy. Dialysis supports the kidneys but does nothing for the pulmonary haemorrhage or the underlying antibody-mediated injury.

The point: Pulmonary–renal syndrome: anti-GBM disease, ANCA-associated vasculitis, and lupus. Send anti-GBM and ANCA together and treat urgently. Dialysis dependence at presentation with widespread crescents predicts poor renal recovery, but pulmonary haemorrhage is still an absolute indication for plasma exchange.

Source: KDIGO clinical practice guideline for the management of glomerular diseases KDIGO · tier 2, specialty society or college