Clinical features and outcomes of renal amyloidosis in Hong Kong

Early symptoms of primary (AL) amyloidosis are non-specific. Any delay in diagnosis and treatment results in poor outcome despite increasing treatment options. We aimed to determine baseline risk factors that identify patients with poor kidney outcomes and overall survivals.

We recruited all patients aged 18 years or above with biopsy-proven renal amyloidosis between years 2000 and 2019 in three Hong Kong regional hospitals. Patients' clinical and pathological parameters, treatment response, kidney outcomes and overall survivals were recorded and analysed.

Thirty-six cases of renal amyloidosis were recruited. Four cases were diagnosed to have multiple myeloma. Edema was the most common presenting symptom. The mean estimated glomerular filtration rate (eGFR) was 98.8 ml/min/1.73 m² at presentation. Autologous stem cell transplant conferred the best renal outcomes as well as patients' survival. Twenty-two patients had 50% decrease in eGFR, 12 patients developed end-stage kidney disease (ESKD) and 22 patients died. Hypertension, diabetes mellitus, proteinuria and low eGFR were identified as independent baseline risk factors for ESKD. Proteinuria, hyperlipidemia, and cardiac involvement were independent baseline risk factors for death.

Amyloidosis, a rare disease with poor prognosis without treatment. Hypertension, diabetes mellitus, heavy proteinuria and low eGFR at diagnosis were associated with poor kidney outcome.