IgG Fc N-glycans · Krištić 2014 · lectin ELLA analogue

Glycan Age: read biological age from an IgG lectin profile

Serum IgG Fc N-glycans change with age: agalactosylated G0/FA2B rises, digalactosylated G2/FA2G2 and FA2BG2 fall, sialylation falls, and bisecting GlcNAc rises. Krištić et al. combined three UPLC peaks into GlycanAge, explaining about 58% of chronological-age variance. This page maps the same biology onto LeGenD's eight-lectin ELLA: enter IgG lectin intensities to estimate glycan age, with a 100-person simulated cohort.

What Glycan Age measures

Research and commercial GlycanAge assays mostly use the UPLC N-glycome of purified serum IgG, not cell-surface FACS. The core observation comes from 5,117 Europeans (Krištić et al., 2014) and later Han Chinese cohorts: IgG glycoforms track chronological age, and residual variance correlates with biological-age traits such as blood pressure, lung function, and glucose. G0-rich IgG is more pro-inflammatory and has higher ADCC, so glycan age is also read as a molecular clock of low-grade chronic inflammation.

Increases with age

FA2 and FA2B (G0; GP6 in the paper). Terminal GlcNAc is exposed → WGA and PHA-E tend to rise and RCA-I falls.

Decreases with age

FA2G2 and FA2BG2 (G2; GP14, GP15) plus FA2G2S1/S2. Terminal Galβ1,4 and α2,6-Sia → RCA-I and SNA tend to fall.

Sex and lifestyle

Premenopausal women usually have higher galactosylation (younger glycan age). Smoking, obesity, and chronic inflammation push glycan age up; exercise does the opposite.

The published GlycanAge index combines agalactosylated GP6 with digalactosylated GP14 and GP15, with about 9.7 years error versus chronological age. This page uses lectin proxies instead: WGA≈G0, RCA-I≈G2, PHA-E≈bisecting, SNA≈α2,6-sialylation, then inverts to a biological glycan age. It is a teaching model, not the Genos/GlycanAge commercial formula, and not a clinical test.

Enter IgG lectin ELISA (OD450) to predict glycan age

Enter ELLA/ELISA OD450 after coating IgG (background may be included). RCA-I, WGA, PHA-E, and SNA are required; LCA checks that the map looks like core-fucosylated IgG.

Simulated 100-person IgG ELISA cohort

A fixed random seed creates 100 adults aged 22–78. Each person has chronological age, sex, and lifestyle, then a hidden biological glycan age and IgG glycoform mix. ELLA OD450 is simulated with the same lectin-binding rules as the profiler. Click a row to load that ELISA into the predictor above.

Chronological age vs predicted glycan age

The diagonal is glycan age = chronological age. Points above the line have an older glycan age. Source: this simulated cohort (seed 2024).

Cohort summary

ID Sex Chrono Glycan age Δ LCA RCA-I WGA PHA-E SNA MAL-I PHA-L DSL Lifestyle