Neurologist to speak on brain and immune system at PI conference

Primary immunodeficiency (PI) is a complex condition. While PI often weakens the immune system’s ability to fight infections, it can also cause the immune system to attack the body, a process called autoimmunity. One of the organs vulnerable to attack is the brain.

“We like to talk about the blood-brain barrier like it’s a solid thing that, when functioning properly, separates the immune system from the central nervous system. While this is a way of understanding an aspect of our anatomy, it’s not the complete story. Fundamentally, it’s important to recognize that the brain and the immune system do interact,” said Dr. Tammy Smith, an autoimmune neurologist at the University of Utah.

The problem is that immune cells in the brain can send inflammatory stress signals when they need assistance from other immune cells in the body to help clean up waste, like dead cells, proteins, and lactic acid. When immune cells that are outside of the brain move into the brain, sometimes there are negative repercussions, such as autoimmunity.

“For example, when you have an infection in your brain, you need to recruit immune cells to cross the blood-brain barrier and help fight that infection. Autoimmunity can develop if those immune cells become overactive and start attacking the brain,” said Smith.

“There’s this quote that I keep next to my desk on a sticky note, and it says, ‘Immunity is beneficial only to the extent that it is effectively dealing with a threat more dangerous than itself.’ That is so apt because immunity is a double-edged sword.”

Smith is one of many speakers who will be presenting at the Immune Deficiency Foundation’s 2026 National Conference set for June 25-27 in San Antonio, Texas. Smith, who holds a Ph.D. in cell biology and immunology and an M.D. in neurology, treats patients with a broad range of neurologic conditions and her research focuses on immune-mediated neurologic disorders.

Her presentation, “Neurological health & PI,” will cover results of a 2023 study, Neurologic Manifestations of Common Variable Immunodeficiency (CVID): Impact on Quality of Life. The study, funded by a research grant from the Immune Deficiency Foundation, surveyed 78 patients with CVID and found a high incidence of neurologic symptoms, with more than 85% stating they had sleep problems, fatigue, and headaches. Other neurologic issues reported by almost 65% of respondents included depression, dizziness, muscle weakness, memory difficulty, changes in vision, numbness/tingling/burning, and pain.

“When caring for people living with immunodeficiency, we often pat ourselves on the back for protecting our patients from infection while overlooking common things like headaches, sleep disturbances, and fatigue. These symptoms can impact peoples’ quality of life, and are worth telling your doctor about,” said Smith.

Not much data exists on specifically treating neurologic symptoms in people with PI, said Smith, but clinicians can address these symptoms as they do in other patients.

“We don’t know what treatments work best in people living with PI, but we can work with our PI patients to better understand the symptoms they have, the treatments they’ve tried, and what benefits or downsides they’ve had from them. By listening and working together with our patients over time, we can improve their lives and futures,” said Smith.

Smith encourages patients to advocate for themselves, even if their doctors don’t necessarily acknowledge their neurological symptoms.

“One strategy is to have an advocate in your corner who goes with you to your doctor’s appointment to say, ‘Hey, you are overlooking this headache issue. Their migraines keep them out of work for five days a month or from participating in their family life in their free time. What can we do about that?’ This can help ensure symptoms impacting patients’ lives are not missed,” said Smith.

Smith said her first approach to solving neurologic issues is often to examine lifestyle factors that may impact the symptoms—sleep, diet, hydration, exercise, and stress. If addressing these factors doesn’t give the results her patients are looking for, then she discusses the pros and cons of long-term and short-term medication use.

“I think it’s about awareness. As healthcare providers, we need to hold ourselves to a higher standard than just preventing infections or relapses of autoimmunity. That is only one piece of the puzzle. We need to ask ourselves if our patients are able to engage in their lives fully. Are they able to get back to taking care of their family, participating in activities that bring meaning to their lives—whether they involve work or play?” said Smith.

“I want people living with PI to know that they can talk to their healthcare providers about all of their symptoms. During my session at the IDF conference this June, we will work through strategies to empower people to address neurologic symptoms through lifestyle interventions and self-advocacy. I look forward to meeting many of your readers there” said Smith.

Smith will speak about the neurological impact of PI on Saturday, June 27 at 9 a.m. in the JW Marriott San Antonio Hill Country Grand Ballroom at the IDF National Conference.