Sophisticated laboratory testing solved a medical riddle and finally got Jori Pearson back on his feet, doing what he loves.

Jori Pearson was a 39-year-old homebuilding contractor with a passion for golf and fishing when he began feeling numbness in his hands. That was in 2013. And those early symptoms signaled the start of a four-year medical odyssey, although Jori and his wife, Kerri, didn't realize that at the time. While Jori's symptoms worsened — causing him at one point to need a wheelchair — no one could provide a definite diagnosis to explain why.

The answer finally came, thanks to a Mayo Clinic Laboratories blood test (Test ID: CIDP) that identified a rare antibody known as NF155 that was attacking Jori's nerves. The diagnosis allowed Jori to get the treatment he needed to halt the attacks.

"Knowing whether somebody is positive for the NF155 antibody is crucial because that tells us what to do for the patient," says Divyanshu (Div) Dubey, M.B.B.S., an autoimmune neurologist at Mayo Clinic who helped develop the blood test. "NF155 can be a progressive disease if not treated appropriately. Patients can have lasting deficits that, at some point, become irreversible."

Jori Pearson

Twisted ankles, bouncing road signs

At first, Jori's doctor in Kearney, Nebraska, thought his numb hands were symptoms of carpal tunnel syndrome. "Carpal tunnel seemed like just an occupational hazard that happens over the years," Jori says. But soon, Jori had trouble walking. His ankles kept twisting, and he couldn't keep his balance. Then he started seeing double and had the illusion that stationary objects were moving.

"When I was driving down the road, signs would appear to be bouncing," he says. "I was stumbling and falling quite a bit. It was like walking and not knowing where your feet were going to land."

Told that his symptoms might be due to pressure on his upper spinal cord, Jori underwent neck surgery in 2014. Spinal compression in the neck can cause problems with balance and dexterity, and it's relatively common as people age. But Jori was 40. And although the surgery relieved some mild compression in his neck, his symptoms continued to worsen.

Within months, Jori needed ankle orthotics and a walker. He started using a wheelchair for longer distances. "Golf and fishing were pretty much out," he says. "My building crew was fortunately able to carry through projects while I tried to run things behind the scenes. But eventually I quit trying to do that, too."

"It was extremely difficult to see him go from being such a physically active guy to suddenly having to sit in a chair, not knowing what was going to happen day-to-day," Kerri says.

That’s when Jori and Kerri turned to Mayo Clinic.

A partial answer

After an initial examination and laboratory tests, Mayo Clinic neurologist Sarah Berini, M.D., suspected a rare neurological problem. She thought Jori's immune system might be attacking the protective coverings around his nerves, damaging them and causing progressive muscle weakness. The condition — a type of demyelinating neuropathy known by its initials, CIDP — can affect people of any age.

"We really don't know what causes CIDP. It is an autoimmune condition," Dr. Berini says. "When we see clinical features that suggest CIDP, we have a series of treatments that are typically helpful."

Treatment starts with immunoglobulin given through the veins, or IVIg. It works by suppressing the immune system to stop the attacks on the nerve coverings. IVIg is effective for most people with CIDP. But not for Jori. His symptoms worsened despite high doses of IVIg. "We were still going backwards," Jori says. "That was difficult."

Dr. Berini recommended second-line therapies: high-dose steroids and plasma exchange, a procedure that cleanses the blood of harmful antibodies. Plasma exchange takes about two hours and must be done regularly. Jori had to travel four hours round trip to Lincoln, Nebraska, for the procedures.

"Kerri drove. It would burn a whole day, pretty much," Jori says. "From 2014 to 2018, we did that twice a week, off and on." The treatments helped. "Not leaps and bounds, but I was a little better," Jori says. "That made it easier to have a positive attitude."

The routine was tough, though. Kerri, a realtor, was a loving and steadfast support, but she had to juggle work commitments to drive to Lincoln. Jori had a passage to his blood vessels — known as a fistula — surgically created to make plasma exchange easier. "The fistula would quit working from time to time, and I'd have to get revisions done," he says. "For a while, it was just one thing after another."

A rare condition's rarer subtype

But science was starting to catch up. Researchers began identifying various subtypes of CIDP based on the antibodies produced by an individual’s immune system. After reading about the NF155 subtype, Dr. Berini suspected that Jori had it. That would explain why IVIg failed to help.

"IVIg works remarkably well for most people with CIDP. The only exception is the subset of CIDP involving very rare antibodies — NF155 being one of them," Dr. Dubey says.

NF155 antibodies are found in only 4% to 18% of people with CIDP. Jori's blood was tested at an outside center, and the result was negative, indicating he didn't have the rare subtype. Undaunted, Dr. Berini suggested that Jori try rituximab, an immune-suppressing medication known to treat NF155. His symptoms improved. But then, due in part to the lack of an official diagnosis of NF155, Jori's insurer refused to cover the cost of the medication.

Dr. Berini consulted Dr. Dubey about analyzing Jori's blood again, using the more-sophisticated NF155 blood test in development at Mayo Clinic Laboratories. Both specialists suspected that the original test's failure to detect NF155 antibodies in Jori's blood was due to his plasma exchange, which removes antibodies.

Fortunately, Mayo Clinic had taken a blood sample from Jori when he first saw Dr. Berini in 2014, before he began treatment. When tested using Mayo Clinic's NF155 antibody test, the sample was positive.

"That was remarkable. It was the answer that we knew was in front of us, but we could never grab hold of it," Dr. Berini says. "Having that diagnosis was integral for me to have a good discussion with the insurance company about why this medication is needed."

The odyssey was over. "Getting the actual confirmation of a diagnosis — I never thought we would," Jori says. "We turned the corner once I started regular rituximab."

Within two months, his strength and stability improved. He was able to stop having plasma exchange and began work as a project manager at a building company in Kearney.

Specific results for focused treatment

Mayo Clinic Laboratories' NF155 antibody test is the first commercially available CIDP antibody test in the U.S. to use flow cytometry to confirm the NF155 subtype of CIDP. Flow cytometry is a sophisticated laboratory technique that provides more specific test results. That specificity is key to providing therapy that can prevent permanent disability.

Jori, who continues to have follow-up exams and occasional rituximab, has experienced few lasting deficits. Despite some numbness in his feet, he can walk without aid. "I can even jog for short periods," he says. He plays golf for fun, and he's back to fishing. Last year, he traveled to the Dominican Republic and walked on the beach.

Although Jori no longer works on construction sites, he was able to renovate the home he and Kerri bought in 2018. "I hired some friends to help me with the roof framing, but I did most of the carpentry and all of the finishing work," he says. "My life is pretty normal now. We're forever grateful to Dr. Berini and everyone else at Mayo Clinic for getting us where we are today."