SERUM LEVELS OF FREE KAPPA AND LAMBDA LIGHT CHAINS IN PATIENTS WITH SYSTEMIC AL, AA, AND ATTR AMYLOIDOSIS

摘要

Immunoglobulin light chains are precursors of AL amyloid fibrils. Free light chains can be quantified with a recently described immunoassay and appear to be useful in AL amyloidosis (1, 2).OBJECTIVETo study the value of serum free light chains for the diagnosis of systemic AL amyloidosis and for monitoring effects of therapy.PATIENTS AND METHODSTwenty-two patients with AL-kappa and 53 with AL-lambda amyloidosis were studied at diagnosis. Controls were 40 healthy blood donors, 9 patients with arthritis, 10 patients with AA amyloidosis, and 10 patients with ATTR amyloidosis. Clonal responses after chemotherapy were evaluated in 20 patients with AL amyloidosis and follow-up of one year or longer.Free kappa and lambda light chains in stored serum samples were quantified with a nephelometric immunoassay (FreeLite~(TM)) with specific antibodies raised against hidden epitopes. The 99% confidence limits of controls were calculated for kappa, lambda, and the ratio of both light chains.