Clinical outcome of immunoglobulin light chain amyloidosis affecting the kidney.

BACKGROUND

The kidney is affected by immunoglobulin light chain amyloidosis (AL) in more than 50% of patients who present with the disease, but long-term predictors for and outcomes after renal replacement therapy are not well described.

METHODS

Kaplan-Meier and multivariate analyses were performed in a uniformly treated cohort of 145 patients with biopsy-proven AL who were monitored for at least 11 years. Outcome measurements were needed for renal replacement therapy and survival.

RESULTS

Among patients presenting with renal AL, 42% ultimately received renal replacement therapy versus 5% of patients who did not have this presentation. Patients with renal amyloid who received dialysis support had significantly higher serum creatinine and 24-h urine protein levels at presentation. Patients with lambda light chain amyloid were significantly more likely to have renal involvement and had significantly greater urinary protein loss than patients with kappa light chain amyloid. Serum creatinine level was an independent predictor of overall survival when corrected for cardiac involvement. For 38 patients who received dialysis, median survival from Day 1 of dialysis was 10.4 months, and 26% of patients with AL ultimately received renal replacement therapy versus 42% of patients who presented with renal AL specifically.

CONCLUSIONS

Presenting 24-h urine protein loss and creatinine values predict which patients will require dialysis. Median survival for patients starting dialysis is <1 year. The presence of lambda light chain amyloid predicts the increased likelihood of renal involvement.