We previously reported that patients with familial amyloidotic polyneuropathy (FAP) (Met30) showed low plasma apolipoprotein AII (apoAII) levels and apolipoprotein AII/AI (apoAII/AI) ratio as the progression of the disease while plasma levels of apoAI, B, CII, CIII, and E were all within normal ranges. In the present study, we investigated these apolipoproteins contained in high density lipoprotein (HDL) extracted from plasma of FAP (Met30), and the levels of apoAII gene expression in the liver from patients with FAP (Met30). Plasma apoAII levels and the apoAII/AI ratio in extracted HDL in all the FAP types examined decreased compared with those in normal control subjects. Levels of apoAII mRNA expression in the liver of FAP (Met30) patients did not show significant changes compared with those in control subjects. These results suggest that decreased affinity of apoAII to HDL could not be compensated by overproduction of apoAII in the liver of the FAP patients and as a result of this phenomenon, plasma apoAII levels might decrease as the progression of FAP.