MAUI, HAWAII – Recent studies highlight novel applications of musculoskeletal ultrasound across a broad spectrum of rheumatic diseases beyond the imaging method’s well-established role in diagnosis and follow-up of patients with rheumatoid arthritis, Alvin F. Wells, MD, PhD, said at the 2018 Rheumatology Winter Clinical Symposium.
He cited recently published evidence in support of his contention:
Systemic lupus erythematosus
Portuguese investigators reported that 77% of their study participants with asymptomatic systemic lupus erythematosus (SLE) – that is, no arthralgia or musculoskeletal signs or symptoms on physical examination – demonstrated gray-scale ultrasound evidence of grade 1 or greater synovial hypertrophy of joints in the hands and/or wrists on a semiquantitative 0-3 scale. So did 100% of patients with symptomatic SLE in this small study, in which physicians evaluated 22 joints per person.
Moreover, grade 1 or greater intra-articular power Doppler changes were also detected in one-fifth of the asymptomatic patients and 83% of those with symptomatic SLE. What the researchers considered persuasive ultrasound evidence of synovitis – grade 2 or 3 synovial hypertrophy or at least grade 1 power Doppler findings – was noted in 23% of the asymptomatic SLE patients, 83% of those who were symptomatic, and none of the healthy controls.
The investigators concluded that asymptomatic patients with SLE may present with subclinical joint inflammation that often goes undetected by physical examination and x-ray. They added that ultrasound with power Doppler may be important in disease evaluation and therapeutic monitoring in patients with lupus ().
For Dr. Wells, the take-home message was clear: “Don’t overlook the hands.”
“In my lupus patients, sure, I look at the hips, making sure there are no subtle signs of osteonecrosis, but I think we often forget to look at the hands. We’re looking at the hair, looking at the mouth, we’re worried about the lungs. But I think we often overlook the synovitis. These patients are going to the ER because they’re having pain in their hands, and they’re getting told, ‘This is fibromyalgia, go back and see your rheumatologist.’ So it’s something to think about: When you’ve got a patient with active lupus, ultrasound may have a role to play,” according to Dr. Wells.
The big unanswered question is whether early aggressive treatment in SLE patients with these synovial abnormalities – that is, a treat-to-target, ultrasound-guided strategy – can limit erosive changes, avoid disease progression, and improve functional outcomes, as is now known to be the case in RA. Long-term studies will be required to find out, he noted.
Ultrasound of parotid glands in suspected Sjögren’s syndrome is biopsy sparing
Members of the European League Against Rheumatism Ultrasound Primary Sjögren’s Syndrome Study Group recently reported that in a prospective study of 103 consecutive outpatients with clinically suspected primary Sjögren’s syndrome, a positive ultrasound examination of the major salivary glands in combination with the presence of anti-SSA/Ro antibodies was highly predictive of positive parotid and labial gland biopsies. Indeed, a positive ultrasound plus anti-SSA/Ro antibodies showed a high predictive value for Sjögren’s syndrome regardless of whether the classification was based upon American College of Rheumatology, American European Consensus Group, or ACR-EULAR criteria ().
“Ophthalmologists, dentists, and primary care physicians frequently refer patients with dry eyes and dry mouth to us to sort out whether they have Sjögren’s syndrome. The data show now that with a positive salivary gland ultrasound score and a positive anti-SSA/Ro antibody test you can avoid the biopsies,” the rheumatologist said.
That’s a fine thing for patients because these biopsies often result in residual numbness and tingling, he added.
Dr. Wells noted that a multicenter European group recently fine-tuned the criteria for an abnormal salivary gland ultrasound score. They identified echogenicity and homogeneity as the two most reliable items on the score. They also reported that the mean time it took five ultrasonographers to perform salivary gland assessments was reasonable at 11-27 minutes ().
“You can do this essentially in an office visit. The changes in the salivary glands are pathognomonic for Sjögren’s – you won’t get it confused with a neoplasm. I schedule these patients for a 15-minute time slot, and based upon the ultrasound and whether they’re positive or negative for anti-SSA/Ro antibodies I can make some decisions from there,” Dr. Wells explained.
He described what to look for on ultrasound: “A normal parotid looks like a homogeneous gray sponge on ultrasound. In Sjögren’s syndrome, you see icepicklike holes in the sponge. And there’s thickening of the intima, so you see blunting of the arterial wave on pulse wave.”