Nucleotide oligomerization domain polymorphism confers no risk to Guillain-Barré syndrome

Interleukin-10 promoter polymorphisms and haplotypes in patients with Guillain-Barré syndrome

OBJECTIVE

Interleukin-10 (IL-10) is a multifunctional cytokine that exerts both pro- and anti-inflammatory effects on the immune system as well as in the pathogenesis of Guillain-Barré syndrome (GBS). We investigated whether the three common polymorphisms -1082 G/A(rs1800896), -819 C/T(rs1800871), and -592 C/A(rs1800872) in the promoter region of IL-10 have any influence on the susceptibility, severity, and clinical outcome of GBS.

METHODS

IL-10 promoter polymorphisms were investigated in 152 patients with GBS and 152 healthy controls from Bangladesh using polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP), and allele-specific oligonucleotide-PCR (ASO-PCR). Haplotype patterns and frequencies were analyzed using Heatmaply R-package, chi-square, and Fisher's exact test. The serum level of IL-10 was measured through enzyme-linked immunosorbent assays. p-values < 0.05 were considered statistically significant.

RESULTS

IL-10 promoter polymorphisms -1082 G/A, -819 C/T, and -592 C/A were not associated with GBS susceptibility. The homozygous -819 TT genotype showed a tendency with susceptibility (p = 0.029; pc = 0.08) and was prevalent in axonal variants of GBS compared to demyelinating subtypes and controls (p = 0.042, OR = 8.67, 95% CI = 1.03-72.97; pc = 0.123 and p = 0.005, OR = 4.2, 95% CI = 1.55-11.40; pc = 0.015, respectively). Haplotype analysis revealed 19 patterns of genotypes and high IL-10 expression haplotype combinations (GCC/GTA, GCC/ATA, and GCC/GCA) may have influence on disease severity (p = 0.026; pc = 0.078). Serum expression of IL-10 was elevated in GBS patients ([GBS, 12.16 ± 45.71] vs. [HC, 0.65 ± 5.17] pg/mL; p = 0.0027) and varied with disease severity ([severe-GBS, 15.25 ± 51.72] vs. [mild-GBS, 3.59 ± 19.79] pg/mL, p = 0.046).

INTERPRETATION

The -819 TT genotypes influence axonal GBS, and high frequency of IL-10 expression haplotype combination with elevated serum IL-10 may play an important role in disease severity.

Triggers of Guillain-Barré Syndrome: Campylobacter jejuni Predominates

Guillain-Barré syndrome (GBS) is a rare immune-mediated acute polyradiculo-neuropathy that typically develops after a previous gastrointestinal or respiratory infection. This narrative overview aims to summarise and discuss current knowledge and previous evidence regarding triggers and pathophysiology of GBS. A systematic search of the literature was carried out using suitable search terms. The most common subtypes of GBS are acute inflammatory demyelinating polyneuropathy (AIDP) and acute motor axonal neuropathy (AMAN). The most common triggers of GBS, in three quarters of cases, are previous infections. The most common infectious agents that cause GBS include Campylobacter jejuni (C. jejuni), Mycoplasma pneumoniae, and cytomegalovirus. C. jejuni is responsible for about a third of GBS cases. GBS due to C. jejuni is usually more severe than that due to other causes. Clinical presentation of GBS is highly dependent on the structure of pathogenic lipo-oligosaccharides (LOS) that trigger the innate immune system via Toll-like-receptor (TLR)-4 signalling. AIDP is due to demyelination, whereas in AMAN, structures of the axolemma are affected in the nodal or inter-nodal space. In conclusion, GBS is a neuro-immunological disorder caused by autoantibodies against components of the myelin sheath or axolemma. Molecular mimicry between surface structures of pathogens and components of myelin or the axon is one scenario that may explain the pathophysiology of GBS.