Stability of apolipoprotein(a) isoform phenotype to postmortem conditions

Studies, such as the one entitled Pathobiological Determinants of Atheroscl erosis in Youth or PDAY, have investigated the relationship of atherosclero tic lesions with lipid and lipoprotein risk factors. However, it is possibl e that proteolytic hydrolysis during the postmortem period could alter prot ein components of lipoproteins. Apo(a) is die defining protein of Lp(a), a lipoprotein associated with risk of cardiovascular disease. Apo(a) proteins are highly polymorphic for size and we simulated, using baboon tissues, th e postmortem conditions for the PDAY study in order to determine their effe cts on apo(a) phenotypes. The bulk of the postmortem samples (93%) were cor rectly phenotyped and showed little or no evidence of degradation. Thus, ap o(a) isoform size phenotypes can be determined in postmortem samples, altho ugh with caution. (C) 1999 Elsevier Science B.V. All rights reserved.