What criteria should I use to determine when to refer a patient with IgA nephropathy to a nephrologist?

Refer a patient with IgA nephropathy to a nephrologist if any of the following criteria are met:

• A 5-year risk of needing renal replacement therapy greater than 5%, as measured by the 4-variable Kidney Failure Risk Equation.
• Accelerated progression of chronic kidney disease, defined as a sustained decrease in eGFR of 25% or more within 12 months with a change in CKD category, or a sustained decrease in eGFR of 15 mL/min/1.73 m2 or more within 12 months.
• A urinary albumin:creatinine ratio (ACR) of 70 mg/mmol or more, unless proteinuria is known to be caused by diabetes and is appropriately managed.
• An ACR of more than 30 mg/mmol together with persistent haematuria after excluding urinary tract infection.
• Hypertension that remains uncontrolled despite the use of at least four antihypertensive drugs at therapeutic doses.
• Known or suspected rare or genetic causes of CKD, which may include IgA nephropathy if genetic suspicion exists.
• Suspected renal artery stenosis or complications of CKD such as renal anaemia, mineral and bone disorder, persistent metabolic acidosis, or diagnostic uncertainty.

These criteria align with the NICE guideline NG203 on chronic kidney disease assessment and management and the CKS chronic kidney disease guidance, which apply to IgA nephropathy as a cause of CKD requiring specialist nephrology input when these risk or progression factors are present.