SPOTLIGHT ON TECHNOLOGY & TECHNIQUE

More than dry eye?

Test uses biomarkers to diagnose and treat Sjögren’s syndrome early.

By Zack Tertel, Senior Associate Editor

While Sjögren’s syndrome poses challenges for patients and clinicians alike, Sjö (Nicox, Inc.), an in-office panel test, uses biomarkers aimed to provide early, accurate diagnosis of the disease.

A patient must exhibit at least four of the six diagnostic consensus criteria to confirm the diagnosis. These include subjective and objective ocular dryness, subjective and objective oral dryness, presence of anti-SS-A/Ro or anti-SS-B/La and abnormal minor salivary gland biopsy.

However, these traditional antibody markers of autoimmune disease do not tell the whole story — approximately one third of SS-A and SS-B results are false negative in Sjögren’s syndrome patients, according to Sjögren’s Syndrome Foundation.

In addition to traditional markers of autoimmune disease, Sjö tests for three novel proprietary biomarkers.

“I will sometimes continue to have a high level of clinical suspicion for Sjögren’s syndrome in dry eye patients despite laboratory test results returning negative for ANA, RF, SS-A and SS-B,” says Laura M. Periman, MD, at Redmond Eye Clinic in Seattle.

Sjögren’s syndrome patients may experience extraglandular ophthalmic complications, including corneal ulceration, corneal melt/perforation, cicatrizing conjunctivitis, uveitis, optic neuritis or retinal vasculitis as well as lymphoma.¹

“Sjögren’s syndrome patients are not receiving proper diagnosis and treatment given the high false negative rate of traditional Ro/La testing. Additionally, disease prevalence estimates tell us that 4% of the population and approximately 10% of dry eye patients have Sjögren’s syndrome,” Dr. Periman says.² “With early diagnosis and treatment, the potential to make a significant impact on a patient’s overall and long-term health is tremendous.”

HOW IT WORKS

In addition to traditional antibody markers of autoimmune disease, including ANA, RF, SS-A (Ro) and SS-B (La), Sjö tests for three novel proprietary biomarkers: carbonic anhydrase 6 (CA-6), parotid secretory protein and salivary protein 1 (SP 1). Antibodies to CA-6 occur very early in Sjögren’s syndrome patients and add additional sensitivity to an early diagnosis, says Dr. Periman.

“My patients with elevated CA-6 antibodies will often report dry mouth and dental problems,” she says.

Dr. Periman adds that SP-1 proteins have great specificity and sensitivity to Sjögren’s syndrome.

TEST PROCESS

Before the test, the patient signs a form that allows the lab to directly bill their insurance. The physician (or technician, depending on state regulations on delegation) sticks the spring-loaded, self-retracting lancet on the ring fingertip of the patient’s non-dominant hand, a process Dr. Periman says her technician learned quickly. Then, the gloved technician or the patient milks the finger until a large drop appears, which falls into a circle on the filter paper. This is more effective than blotting the filter paper collection card, Dr. Periman says.

After placing a droplet in the five required circles, Redmond Eye Clinic adds three to four additional droplets to ensure the lab has enough sample to perform the assay.

After allowing the sample to air dry for 30 minutes, they send the sample, patient information card, orders and diagnostic codes in a paper envelope and postage-paid biohazard shipping envelope supplied in the kit. Physicians can expect results within seven to 14 days, Dr. Periman says.

PATIENT SELECTION

Along with the Sjögren’s syndrome diagnostic criteria, Dr. Periman says she typically uses the test for patients with a family history of the disease. Other candidates include patients with symptoms out of proportion with risk factors (such as young patients with no dry eye risk factors) and those with a history of dermatologic, neurologic, gastrointestinal or musculoskeletal disorders.

“We know that approximately 10% of patients in a dry eye clinic have Sjögren’s Syndrome, so I know I need to be aggressive in testing for this condition,” Dr. Periman says.

BENEFITS

“The Sjö panel test for Sjögren’s syndrome is fast and extremely easy to administer,” Dr. Periman says. “Patients readily accept and participate in the test.”

In addition to patient satisfaction, the Sjö test can also benefit a practice. Dr. Periman says Sjö helps distinguish the practice as a site of excellence in offering state-of-the-art services, diagnostics and treatments while contributing to her referral network.

“It is exciting and rewarding to offer this fast and simple clinical diagnostic technology to aid in early diagnosis of Sjögren’s syndrome, prevent complications and potentially save a patient’s sight,” Dr. Periman says. OM

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