Rituximab Safe, Effective in Case of Sjogren’s-related ILD
This case adds to a growing number of reports and case series showing that rituximab lessens lung involvement in Sjögren’s patients, further supporting the usefulness of the immunosuppressive treatment in this patient population.
It also highlights the importance of screening for Sjögren’s-specific symptoms in people showing ILD, the researchers noted.
The case study, “Rituximab for the treatment of acute onset Interstitial Lung Disease in primary Sjogren’s syndrome,” was published in the journal Pulmonology.
Primary Sjögren’s syndrome is a chronic autoimmune disease in which the immune system mistakenly attacks glands that produce secretions, mainly the salivary and lacrimal (tear) glands. But it also can affect other tissues, including the lungs, brain, kidneys, and gastrointestinal tract.
ILD is a group of more than 200 lung disorders in which the tissue in and around the air sacs becomes inflamed and scarred, affecting breathing and the lungs’ ability to transfer oxygen into the bloodstream. It is considered the most frequent and serious pulmonary complication of Sjögren’s syndrome, affecting 3–11% of patients, and is associated with reduced quality of life and early death.
While ILD was typically described as a late manifestation of Sjögren’s syndrome, more recent studies have pointed out that this type of lung disease may occur years before, or at the same time, as the dryness symptoms of the autoimmune disease.
A previous study reported that “10–51% of patients developed ILD years before the onset and diagnosis of pSS [primary Sjögren’s syndrome], while in about 20% of patients the diagnoses of pSS and ILD are concurrent,” the researchers wrote.
While immunosuppressive treatments are commonly used off-label to treat Sjögren’s syndrome and related ILD, its current management “remains empiric and dependent on the medical team’s experience” due to lack of evidence from appropriately controlled trials, the researchers wrote.
Several previous studies have reported positive outcomes with rituximab, an immunosuppressive therapy that targets B-cells — a type of immune cell involved in the production of antibodies and whose abnormalities are linked to Sjögren’s syndrome.
Now, researchers at the University of Modena Reggio Emilia, in Italy, reported the case of a 49-year-old white man with Sjögren’s syndrome, whose sudden ILD onset was successfully managed with rituximab.
On May 2020, the man, who was a former smoker, was hospitalized due to shortness of breath. Clinical and laboratory findings suggested high levels of inflammation, but did not support the presence of an infection, including COVID-19.
However, the first high-resolution computed tomography (HRCT) of the chest showed lung tissue abnormalities suggestive of lung infection, and antibiotic treatment and supplemental oxygen were begun.
Further examination failed to identify any bacteria, viruses, or other germs in the man’s saline mouth rinse sample, and adding other antibiotics to the treatment regimen failed to improve his condition.
In fact, the patient’s clinical and chest radiological features worsened rapidly, and he developed respiratory failure needing further non-invasive oxygen support and mechanical ventilation.
After he was transferred to the respiratory disease unit, other diagnostic tests were performed, revealing the presence of Sjögren’s-related autoantibodies and excessive numbers of immune cells in the salivary gland — all highly suggestive of primary Sjögren’s syndrome.
In addition, lung biopsies performed earlier showed an organizing pneumonia lung pattern, which is the second-most frequent ILD lung pattern in Sjögren’s syndrome.
These findings prompted the diagnosis of Sjögren’s syndrome-related ILD and the man was prescribed rituximab, given directly into the bloodstream at a dose of 375 milligram per square meter (mg/m2) once a week for four weeks, and prednisolone (1 mg/kg each day), an anti-inflammatory and immunosuppressive corticosteroid.
A month later, the man’s lung abnormalities on HRCT were reduced significantly and his respiratory failure was resolved. Given the severity of the clinical manifestations at disease onset, the patient was asked to stop prednisolone and to initiate mycophenolate mofetil as a steroid-sparing and maintenance immunosuppressive therapy to reduce the risk of disease relapse.
Rituximab was considered as a possible rescue therapy, used only if the patient’s symptoms returned while on mycophenolate mofetil.
“The number of reports of the early appearance of ILD in patients with misdiagnosed connective tissue diseases, including pSS, is increasing,” the researchers wrote, adding that a systematic screening for specific symptoms of pSS may be key among people newly diagnosed with ILD.
“According to the current evidence, our experience confirms that rituximab could be a safe and useful treatment for this life-threatening condition,” the team concluded.