The classic symptoms of primary Sjögren’s syndrome – dry eyes and mouth – belie its many systemic problems and complications.
A study from the South Australian Sjögren’s Syndrome Research Clinic and Database has shown almost half (48.8%) of patients have glandular involvement and more than half have articular involvement (53.5%).
Cutaneous manifestations such as vasculitis were also relatively common (15.7%) amongst the baseline characteristics of the 172 patients.
Overall, the median ESSDAI score of the cohort was 6.8 – slightly higher than a comparative score of 6.1 from a larger international cohort in the Big Data Sjögren Project.
The study also found out-of-ESSDAI manifestations, most commonly cardiovascular features, Raynaud’s phenomenon, digestive features, dysphagia and neurological features, were reported in 30.2% of patients with Sjögren’s syndrome.
A quarter (25%) of patients had two or more of these features.
The study found serological screening would miss up to 20% of people with Sjögren’s syndrome. Anti-Ro autoantibodies were the most frequent finding (82.6%), followed by ANA (77.0%) and anti-La (63.2%).
Ro+La+ patients had significantly higher rates of activity in the glandular, cutaneous, and biological ESSDAI domains than Ro+La- or Ro-La- patients.
And the study found that the sub-group of patients who were negative for ANA still had moderate levels of disease activity (ESSDAI 5.1) though less than ANA+ patients (ESSDAI 7.0).
To date, only nine (5.2%) of patients in the SA cohort are known to have developed lymphoma.
Four confirmed cases of congenital heart block and two suspected cases resulting in neonatal deaths were reported in children of patients in the cohort.
Senior investigator Associate Professor Maureen Rischmueller, from the Queen Elizabeth Hospital in Adelaide, told the limbic that making the diagnosis of primary Sjögren’s syndrome can be challenging and time-consuming.
“It’s a disease which has been underrecognised and under diagnosed or misdiagnosed for many years, and still is,” she said.
“Many of the patients have been seven, eight and more years with symptoms and without a diagnosis and they feel like they have been fobbed off.”
She said patients were often labelled as an undifferentiated connective tissue disease.
Yet a specific and accurate diagnosis meant they could be treated as an autoimmune disease with systemic complications, with management including the judicious use of immunosuppression and monitoring for associated condition such as lymphoma.
“People aren’t aware that Sjögren’s syndrome has the highest risk of lymphoma development. It’s about a 10% lifetime risk. It’s a premalignant disease really if you look at it that way,” she said.
Associate Professor Rischmueller encouraged rheumatology colleagues to enquire about dry eye symptoms in patients presenting with aches, pains and fatigue as many patients had reduced sensation of the cornea or had become used to their symptoms.
“A significant number of patients will have negative serology for Ro and La antibodies and require objective measures of ocular and oral dryness, and salivary gland biopsy, to confirm the diagnosis – currently underutilized in Australian rheumatology teaching and practice,” the study concluded.
A proposed national Australian Sjögren’s Registry and Repository is in the early stages of development.