Biopsy Safety Thrombocytopenia SLE — ESENeph MCQ

Correct answer: C — Arrange nephrology assessment and consider kidney biopsy

The best answer is “Arrange nephrology assessment and consider kidney biopsy”. The protein-creatinine ratio exceeds the KDIGO biopsy-consideration threshold of 50 mg/mmol, and haematuria plus active lupus serology increases suspicion. Biopsy determines whether lupus nephritis is present and identifies the class and activity needed to guide therapy. “Reassure her because stable creatinine excludes active lupus nephritis” is less appropriate because clinically important lupus nephritis can present with proteinuria and haematuria before GFR falls “Diagnose the histological class from complement and anti-dsDNA alone” is less appropriate because serology does not establish the kidney histological class needed for treatment decisions “Wait until proteinuria exceeds 3.5 g/day before investigating” is less appropriate because KDIGO uses a much lower threshold of about 500 mg/day or equivalent for biopsy consideration “Begin indefinite cyclophosphamide without obtaining renal histology” is less appropriate because stable kidney function permits appropriate biopsy-led classification before high-risk induction treatment

Reference: KDIGO 2024 lupus nephritis guideline: https://kdigo.org/wp-content/uploads/2024/01/KDIGO_2024_Lupus_Nephritis_Guideline.pdf