Scientists identify shared biological networks linking long Covid, ME/CFS, PTSD and other chronic conditions

Five diseases that seem to have nothing in common—a lingering viral infection, a psychological wound, an autoimmune attack on joints, another on the nervous system, and a mysterious exhaustion that follows no clear trigger—may actually be disrupting the same biological machinery inside the body. Researchers at the University of East Anglia, working with collaborators at Oxford BioDynamics and other institutions, published findings this week in the Journal of Translational Medicine suggesting that long Covid, ME/CFS, PTSD, rheumatoid arthritis, and multiple sclerosis all converge on shared networks governing immunity, metabolism, and cellular energy production. The discovery offers a potential explanation for why patients across these five conditions report strikingly similar symptoms: overwhelming fatigue, brain fog, poor concentration, sleep disturbance, and a collapse of everyday functioning—despite the radically different ways their illnesses began.

For decades, these conditions have been treated as separate puzzles. ME/CFS often emerges after a viral infection. Long Covid develops specifically after SARS-CoV-2 infection. PTSD follows psychological trauma. Rheumatoid arthritis is an autoimmune disease that attacks the joints. Multiple sclerosis attacks the nervous system. The triggers are so different that clinicians have had little reason to suspect a common biological foundation. But lead researcher Dmitry Pshezhetskiy and his team asked a simpler question: if the symptoms overlap so dramatically, might the underlying disruption be the same?

To answer it, they did not sequence new patient DNA or run new blood tests. Instead, they took existing genomic data from published studies of all five conditions and applied a computational tool called the EpiSwitch Orion platform, developed by Oxford BioDynamics. The platform does something conventional genetic analysis cannot: it maps how DNA folds in three dimensions inside cells. DNA does not sit in a line. It coils and loops, bringing distant sections into contact with one another. Those contact points are where genes get controlled. When the researchers applied Orion to the genetic data from all five conditions, a pattern emerged that linear DNA sequencing alone would have missed.

At first glance, the genetic changes associated with each condition looked largely unrelated. But when the researchers analyzed how those genes interact within complex biological networks—how they talk to one another, which systems they feed into—the picture inverted. Suddenly, the five diseases appeared deeply connected. The genes associated with long Covid, ME/CFS, PTSD, rheumatoid arthritis, and multiple sclerosis were all converging on the same major biological systems: immune and inflammatory signaling, mitochondrial energy production, metabolic regulation, stress-response mechanisms, and neuroendocrine signaling. The initial trigger might differ from one condition to another, but the biological disruption that followed appeared to affect the same fundamental machinery.

This finding offers a framework for understanding how such different events could produce such similar suffering. A Covid infection might trigger prolonged immune activation. Traumatic stress might disrupt stress-hormone pathways and inflammatory responses. But both disturbances appear capable of converging on common biological circuits controlling energy production, immune regulation, and cellular resilience. When those systems become persistently dysregulated, the result is the profound and disabling exhaustion experienced by millions. The researchers also identified several "hub genes" positioned at especially active points within these shared networks—genes connected to immune regulation, inflammatory signaling, and mitochondrial energy production. One gene of particular interest, LAG3, has been linked to T-cell exhaustion, a condition in which immune cells become less effective after remaining activated for an extended period. If future studies confirm this connection, it could explain why some patients remain chronically ill even after the initial trigger—infection, trauma, or other stressor—is long gone.

The practical implications could be substantial. ME/CFS and long Covid are currently diagnosed almost entirely through symptoms, with no universally accepted laboratory test available. That absence has left countless patients facing years of diagnostic uncertainty. Previous research using the EpiSwitch platform had already produced a blood-based ME/CFS test showing promising diagnostic accuracy, though it still requires further validation before clinical use. The new findings raise the possibility that shared biological signatures could be identified across multiple conditions rather than ME/CFS alone, potentially opening the door to objective blood tests that identify underlying biological disruption instead of relying solely on what patients report. The researchers also suggest that understanding these shared pathways could eventually point toward treatments relevant to more than one chronic condition—a shift from viewing long Covid, ME/CFS, PTSD, rheumatoid arthritis, and multiple sclerosis as entirely separate disorders to understanding them as different manifestations of disturbed biological networks operating throughout the body. In that framework, chronic exhaustion is not simply a symptom. It is the visible consequence of a deeper systems failure affecting immune function, metabolism, and stress-response pathways. The work offers a unifying theory of fatigue, but it also offers something more: a map for how to begin treating it.