IgG/FcRn is a strong immune age-amplifying axis, but not yet a universal longevity bottleneck

IgG/FcRn is a strong immune age-amplifying axis, but not yet a universal longevity bottleneck

''结论'': IgG/FcRn now meets a stronger bar than purely inflammatory readouts because public evidence includes a mouse healthspan and lifespan signal: Cell Metab 2024 (PMID 38378001) reports that IgG accumulates during aging, especially in white adipose tissue, and that preventing IgG buildup by targeting FcRn in macrophages prolongs healthspan and lifespan in aged mice.

''但'': current evidence is still most convincing in a tissue-limited metabolic/adipose context. That keeps it below a universal bottleneck threshold for now, for three reasons:
# the best mechanism is adipose fibrosis / macrophage activation / insulin resistance, not yet a multi-organ aging reset;
# the intervention is an IgG homeostasis lever, so infection-defense and antibody biology side effects must be treated as first-class constraints;
# it still lacks the kind of cross-organ, cross-sex, and head-to-head comparison against more upstream immune-reset entries like thymic source restoration.

''可复用判断'': when an immune candidate already has lifespan signal but the dominant phenotype remains organ-restricted, classify it as strong longevity-positive rather than universal bottleneck until broader systemic evidence appears.