Soluble TREM2 in body fluid in Alzheimer's disease and Parkinson's disease

BackgroundPrevious studies showed conflicting results regarding soluble triggering receptor expressed on myeloid cells 2 (sTREM2) level alteration in body fluid in Alzheimer's disease (AD) and Parkinson's disease (PD).MethodsWe applied the STATA 12.0 software to compute standard mean difference (SMD) and 95% confidence interval (CI).ResultsThe study showed elevated sTREM2 level in cerebrospinal fluid (CSF) in AD, mild cognitive impairment (MCI), and preclinical AD (pre-AD) patients, compared to healthy controls (HCs) with random effects models (AD: SMD 0.28, 95% CI 0.12 to 0.44, I-2 = 77.6%, p < 0.001; MCI: SMD 0.29, 95% CI 0.09 to 0.48, I-2 = 89.7%, p < 0.001; pre-AD: SMD 0.24, 95% CI 0.00 to 0.48, I-2 = 80.8%, p < 0.001). The study showed no significant difference in sTREM2 level in plasma between AD patients and HCs with a random effects model (SMD 0.06, 95% CI - 0.16 to 0.28, I-2 = 65.6%, p = 0.008). The study showed no significant difference in sTREM2 level in CSF or plasma between PD patients and HCs with random effects models (CSF: SMD 0.33, 95% CI - 0.02 to 0.67, I-2 = 85.6%, p < 0.001; plasma: SMD 0.37, 95% CI - 0.17 to 0.92, I-2 = 77.8%, p = 0.011).ConclusionsIn conclusion, the study highlighted the CSF sTREM2 as a promising biomarker in the different clinical stages of AD. More studies were essential to explore the CSF and plasmatic concentrations of sTREM2 alteration in PD.

Automated summary

The study found elevated levels of sTREM2 in the cerebrospinal fluid of AD, MCI, and pre-AD patients, but no significant difference in plasma levels between AD patients and healthy controls. There was also no significant difference in sTREM2 levels in the cerebrospinal fluid or plasma of PD patients compared to healthy controls. CSF sTREM2 may be a promising biomarker for different clinical stages of AD, while further research is needed to explore sTREM2 alterations in PD.