Elevated cerebrospinal fluid levels of beta-2-microglobulin in patients with Guillain-Barré syndrome and their correlations with clinical features

Backgrounds Beta-2-microglobulin (β2-MG) levels vary in many infectious and autoimmune diseases. We investigated plasma and cerebrospinal fluid (CSF) β2-MG levels in patients with Guillain-Barré syndrome (GBS) and their correlations with clinical parameters. Methods CSF samples from 50 patients with GBS including 19 acute inflammatory demyelinating polyneuropathy (AIDP), 6 acute motor axonal neuropathy (AMAN), 10 acute motor-sensory axonal neuropathy (AMSAN), 7 Miller-Fisher syndrome (MFS), and 8 unclassified patients were collected. Moreover, 23 CSF samples from patients with non-inflammatory neurological disorders (NIND) as controls were collected. Plasma samples from 42 enrolled patients and 29 healthy individuals were also collected. The β2-MG levels were measured by immunoturbidimetry on automatic biochemical analyser. Besides, clinical data were extracted from electronic patient documentation system. Results CSF levels of β2-MG, lactate dehydrogenase (LDH), and lactate were significantly increased in patients with GBS ( p = 0.004, p = 0.041, p = 0.040, respectively), particularly in patients with AIDP ( p < 0.001, p = 0.001, p = 0.015, respectively), whereas no statistically significant difference was found in plasma levels of β2-MG. Furthermore, CSF levels of β2-MG were positively correlated with Hughes functional score ( r = 0.493, p = 0.032), LDH ( r = 0.796, p < 0.001), and lactate ( r = 0.481, p = 0.037) but not with protein ( r = − 0.090, p = 0.713) in AIDP patients. Conclusions CSF β2-MG levels may help identify AIDP and indicate clinical severity. CSF LDH and lactate levels correlate with CSF β2-MG levels; interaction among these biomarkers would need further investigation.