Can persistent infections contribute to neural autoimmunity through molecular mimicry and cross-reactive antibodies?

Persistent infections and post-infectious immune responses can create conditions in which microbial antigens resemble neural structures, but the strength of evidence differs substantially among the organisms named and by neurologic syndrome.

Clinical and immunologic evidence

• EBV has the strongest support as a persistent antigenic and immune-modulating exposure: lifelong latency in memory B cells and intermittent reactivation can sustain B-cell activation and type-I-interferon signaling. In a prospective military cohort, EBV infection preceded MS in nearly all initially seronegative cases and was associated with an approximately 32-fold increase in subsequent MS risk.
• CMV plausibly produces persistent T-cell–centered stimulation, including expansion of CMV-specific CD8+ effector/EMRA cells (“memory inflation”), a particularly relevant immune-aging phenotype in older adults. CMV reactivation has also been associated with increased IFN-α and TNF-α.
• After treated Borrelia infection, elevated CCL19 at one month predicted persistent symptoms at 6–12 months, supporting sustained immune dysregulation; this does not establish viable ongoing infection.
• Mycoplasma pneumoniae and group A Streptococcus are most convincingly linked to post-infectious, rather than demonstrably persistent, immune activation.

Molecular mimicry and neural targets

• Molecular mimicry and cross-reactive antibodies are established contributors to selected neurologic diseases. The canonical example is Campylobacter-associated Guillain–Barré syndrome, where antibodies to bacterial lipooligosaccharides bind neural gangliosides.
• EBNA1-reactive antibodies can cross-recognize CNS proteins including GlialCAM, ANO2, and CRYAB. CMV-associated GBS includes anti-GM2 antibodies recognizing epitopes on CMV-infected cells.
• M. pneumoniae neurologic cohorts show anti-galactocerebroside antibodies: 23/46 cases in one multicenter cohort. In Sydenham chorea, GAS-directed antibodies recognize both GlcNAc and neuronal lysoganglioside GM1. Borrelia flagellin antibodies cross-react with axonal HSP60 in vitro.

Bottom line

• Persistent microbial immune stimulation is a biologically credible contributor—not a universal or sufficient cause—of neural autoimmunity. EBV has the strongest persistence-related case; CMV and Borrelia are plausible; and Mycoplasma and GAS are best supported as triggers of post-infectious molecular mimicry in susceptible individuals.