C4, BF, C3 allele distribution and complement activity in healthy aged people and centenarians

The aim of this study was to examine the complement system and the distribu tion of some human leukocyte antigen (HLA) class III alleles (C4, BF) in he althy aged people (77 centenarians and 89 elderly subjects). We have abo st udied the alleles of C3, a complement component genetically unrelated to HL A, the immunochemical levels of C4 and C3 and serum functional hemolytic ac tivity for classical (CH50) and alternative (AP50) complement pathway. The levels of C3 and C4 and the CH50 and AP50 were found to be within the norma l range. The frequencies of C3, BI; and C4A alleles Here similar in the coh orts that have been studied For C4B null allele (C4BQ0) a trend toward an i ncrease in the older cohort Has observed, although the differences were not significant after statistical correction. Our data suggest that the comple ment system is well preserved in centenarians and elderly subjects and clas s III HLA antigens are equally distributed in aged cohorts and in young hea lthy individuals.