<p>Excessive microglial activation might be a central pathological process in GRN-related frontotemporal dementia (FTD-GRN). We measured soluble triggering receptor expressed on myeloid cells 2 (sTREM2), which is shed from disease-associated microglia following cleavage of TREM2, in cerebrospinal fluid of 34 presymptomatic and 35 symptomatic GRN mutation carriers, 6 presymptomatic and 32 symptomatic C9orf72 mutation carriers and 67 healthy noncarriers by ELISA. Although no group differences in sTREM2 levels were observed (GRN: symptomatic (median 5.2 ng/mL, interquartile range [3.9–9.2]) vs. presymptomatic (4.3 ng/mL [2.6–6.1]) vs. noncarriers (4.2 ng/mL [2.6–5.5]): p = 0.059; C9orf72: symptomatic (4.3 [2.9–7.0]) vs. presymptomatic (3.2 [2.2–4.2]) vs. noncarriers: p = 0.294), high levels were seen in a subset of GRN, but not C9orf72, mutation carriers, which might reflect differential TREM2-related microglial activation. Interestingly, 2 presymptomatic carriers with low sTREM2 levels developed symptoms after 1 year, whereas 2 with high levels became symptomatic after &gt;5 years. While sTREM2 is not a promising diagnostic biomarker for FTD-GRN or FTD-C9orf72, further research might elucidate its potential to monitor microglial activity and predict disease progression.</p>

doi.org/10.1016/j.neurobiolaging.2021.02.024, hdl.handle.net/1765/136361
Neurobiology of Aging
Erasmus MC: University Medical Center Rotterdam

E.L. (Emma) van der Ende, Estrella Morenas-Rodriguez, Corey McMillan, Murray Grossman, David Irwin, Raquel Sanchez-Valle, … H. (Harro) Seelaar. (2021). CSF sTREM2 is elevated in a subset in GRN-related frontotemporal dementia. Neurobiology of Aging, 103, 158.e1–158.e5. doi:10.1016/j.neurobiolaging.2021.02.024