The research, “Evaluation of risk factors for pseudo-obstruction in systemic sclerosis,” was published in the journal Seminars in Arthritis and Rheumatism.
Pseudo-obstruction, a condition with similar symptoms to those of intestinal obstruction but with no physical blockage detected in exams, is a rare but severe complication in people with SSc. However, its risk factors in this patient population are still poorly defined.
Aiming to address this gap, a team at Johns Hopkins University analyzed patients treated at the Johns Hopkins Scleroderma Center between February 2003 and September 2017. To be classified as having pseudo-obstruction, individuals had to have a modified Medsger gastrointestinal (GI) severity score of 3. They also had to present at least three of the following features: abdominal pain, nausea, vomiting, failure to pass gas, bloating, distention, or high-pitched bowel sounds. Alternative causes of obstruction were ruled out based on imaging and physician notes.
Among a total 2,812 SSc patients, 175 (22.9%) had a history of pseudo-obstruction. Their mean age at first symptoms was 44.1 years, and the median disease duration from first symptoms to baseline visit was 5.0 years. The follow-up interval was 3.5 years.
Compared with people without pseudo-obstruction, those with this complication were significantly more likely to be male (23% vs. 15%), have diffuse cutaneous disease (48% vs. 36%), and cardiac involvement (44% vs. 26%). These individuals also were more like to have myopathy, or muscle disease (29% vs. 15%), severe Raynaud’s syndrome (66% vs. 53%), and elevated right ventricular systolic pressure (43 vs. 37 mmHg).
SSc patients with pseudo-obstruction also reported a greater use of opioids (43% vs. 26%) or prokinetics — medicines to improve the motility of the GI tract (63% vs. 16%). They also reported greater use of antibodies against U3RNP, or fibrillarin (7% vs. 3%), and were more likely to die (44% vs. 24%).
Conversely, patients with pseudo-obstruction were less likely to have antibodies against RNA polymerase III, a marker of SSC disease (11% vs. 19%), than those without.
A subsequent analysis confirmed that older age, longer time having the disease, being male, opioid use, and having diffuse cutaneous disease, myopathy, and cardiac involvement, all were significantly associated with pseudo-obstruction in SSc patients. The team further reported that opioid use could be a modifiable risk factor for pseudo-obstruction.
“These clinical features may allow for earlier diagnostic evaluation and/or therapeutic intervention for patients at risk for pseudo-obstruction,” the researchers said.
In particular, “opioid usage should be further evaluated in prospective studies to better understand its role as a modifiable risk factor, and explore how opioid indication, formulation, dosing, timing, and cessation affect the development of pseudo-obstruction,” they added.