Association of IL-6 and TNF-α with IgA/IgG in Iraqi Patients with Multiple Sclerosis

Abstract

Multiple sclerosis (MS) is a chronic inflammatory demyelinating disorder of the central nervous system with immune-mediated demyelination.

Proinflammatory cytokines, including IL-6 and  TNF-α, play a crucial role in neuroinflammation, and immunoglobulin dysfunction (IgA and IgG) reflects humoral immune reactivity. In Iraqi patients, the relationship between these markers remains poorly recognized.

The study aims to assess serum levels of IL-6, TNF-α, IgA, and IgG in Iraqi patients with MS and to examine their interrelationships.

Sixty patients with clinically diagnosed MS and 60 age- and sex-matched healthy controls, aged 18–60 years, were included in the case-control study. Serum IL-6 and TNF-α levels were measured by enzyme-linked immunosorbent assay (ELISA), and IgA and IgG levels were measured by nephelometry. Statistical analyses were performed using t-tests and Pearson's correlation; p < 0.05 was considered statistically significant.

The serum levels of IL-6 and TNF-α were significantly higher in patients with MS (15.87 ± 4.62 pg/mL; 24.65 ± 6.73 pg/mL) than in controls (7.94 ± 2.18 pg/mL; 12.18 ± 3.54 pg/mL, respectively; p<0.001). Levels of IgG (14.52 ± 2.96 g/L) and IgA (3.01 ± 0.78 g/L) were also significantly elevated in patients compared with controls (11.84 ± 2.41 g/L and 2.35 ± 0.65 g/L, p < 0.01). Significant positive correlations were found between IL-6 and IgG (r = 0.418, p < 0.001) and between TNF-α and IgA (r = 0.496, p < 0.001).

A strong association exists between cytokines and immunoglobulins, and concurrent elevations of IL-6, TNF-α, IgA, and IgG are observed in Iraqi MS patients. The strong correlation between TNF-α and IgA may reflect distinct genetic or environmental factors, underscoring the need for region-specific biomarker research and tailored monitoring plans.