PT  - JOURNAL ARTICLE
AU  - Marlena Wosiski-Kuhn
AU  - Mac Robinson
AU  - Jane Strupe
AU  - Phonepasong Arounleut
AU  - Matthew Martin
AU  - James Caress
AU  - Michael Cartwright
AU  - Robert Bowser
AU  - Merit Cudkowicz
AU  - Carl Langefeld
AU  - Gregory A. Hawkins
AU  - Carol Milligan
TI  - IL6 receptor<sup>358</sup>Ala variant and trans-signaling are disease modifiers in amyotrophic lateral sclerosis
AID  - 10.1212/NXI.0000000000000631
DP  - 2019 Nov 01
TA  - Neurology - Neuroimmunology Neuroinflammation
PG  - e631
VI  - 6
IP  - 6
4099  - http://nn.neurology.org/content/6/6/e631.short
4100  - http://nn.neurology.org/content/6/6/e631.full
SO  - Neurol Neuroimmunol Neuroinflamm2019 Nov 01; 6
AB  - Objective To test the hypothesis that patients with amyotrophic lateral sclerosis (ALS) inheriting the common interleukin 6 receptor (IL6R) coding variant (Asp358Ala, rs2228145, C allele) have associated increases in interleukin 6 (IL6) and IL6R levels in serum and CSF and faster disease progression than noncarriers.Methods An observational, case-control study of paired serum and CSF of 47 patients with ALS, 46 healthy, and 23 neurologic disease controls from the Northeastern ALS Consortium Biofluid Repository (cohort 1) was performed to determine serum levels of IL6, sIL6R, and soluble glycoprotein 130 and compared across groups and IL6R genotype. Clinical data regarding disease progression from a separate cohort of 35 patients with ALS from the Wake Forest ALS Center (cohort 2) were used to determine change in ALSFRS-R scores by genotype.Results Patients with ALS had increased CSF IL6 levels compared with healthy (p < 0.001) and neurologic (p = 0.021) controls. Patients with ALS also had increased serum IL6 compared with healthy (p = 0.040) but not neurologic controls. Additive allelic increases in serum IL6R were observed in all groups (average increase of 52% with the presence of the IL6R C allele; p < 0.001). However, only subjects with ALS had significantly increased CSF sIL6R levels compared with controls (p < 0.001). When compared across genotypes, only patients with ALS inheriting the IL6R C allele exhibit increased CSF IL6. ALSFRS-R scores decreased more in patients with ALS with the IL6R C allele than in those without (p = 0.019).Conclusions Theses results suggest that for individuals inheriting the IL6R C allele, the cytokine exerts a disease- and location-specific role in ALS. Follow-up, prospective studies are necessary, as this subgroup of patients may be identified as ideally responsive to IL6 receptor–blocking therapies.ALS=amyotrophic lateral sclerosis; BBB=blood-brain barrier; CHIT-1=chitotriosidase-1; DC=disease control; HC=healthy control; IL6=interleukin 6; IL6R=IL6 receptor; MAF=minor allele frequency; MN=motoneuron; NEALS=Northeastern ALS Consortium; NMJ=neuromuscular junction