Study: Behçet's Disease Research Focuses on Frequently Seen Symptoms

Recent Behçet’s disease research has focused on the most frequently seen disease symptoms, but treatment for rarer disease manifestations may suffer as a result.

Recent Behçet’s disease research tends to favor ocular and mucocutaneous disease manifestations over other disease manifestations, the results of a study published in the January 30, 2014, edition of Orphanet Journal of Rare Diseases suggest.

The research trend aligns with Behçet’s disease symptoms within patient populations, the researchers noted. Although the disorder, which causes inflammation in the body’s blood vessels, can manifest with rheumatologic, ocular, mucocutaneous, neurologic, or cardiovascular symptoms, mucocutaneous and ocular symptoms tend to be seen more frequently than other manifestations.

“In one review, mucocutaneous disease was reported in almost all patients, ocular involvement in up to 69%, join involvement in up to 59%, vascular involvement in up to 38%, and central nervous system involvement in up to 20% of patients with [Behçet’s disease],” the researchers noted. “It could thus be reasoned that ‘supply’ of literature is largely matched to ‘demand’.”

Despite this finding, the researchers argue that the overall research quality has gone down, and that the most recent studies have not focused on rarer disease manifestations.

The researchers compiled all literature describing disease management up to August 2013. Their analysis included pharmacologic and nonpharmacologic treatment options from studies available through PubMed, Medline, EMBASE, and the Cochrane Central Register of Controlled Trials.

Of 255 identified papers, 60 met the study’s inclusion criteria. Many studies were excluded because of small sample sizes, the researchers noted. The overall sample size from all studies included 4302 participants with Behçet’s disease, which included 1555 participants in studies on ocular outcomes, 1420 participants in studies on mucocutaneous outcomes, 1144 participants in studies on cardiovascular outcomes, 449 participants in studies on rheumatologic outcomes, 56 participants in studies on neurologic outcomes, and 109 participants in studies with outcomes classified as “other.”

Ocular and mucocutaneous outcomes were reported in 27 and 26 studies, respectively, researchers noted. Cardiovascular, neurologic, and rheumatologic outcomes were reported as primary outcomes in only 4, 2, and 8 studies, respectively, and as secondary outcomes in 5, 5, and 8 studies, respectively.

Of the 37 therapeutic interventions appearing in the research, the most frequently assessed were biologic therapies, which were assessed in 20 studies, followed by calcineurin antagonists and other immunomodulating therapies, which were assessed in 12 studies each. Nonpharmacologic therapies were assessed in 6 studies and included ocular surgery, hygiene, and laser cardiovascular or dental surgery.

The increase in investigations into biologic therapies coincides with an increased focus on ocular outcomes and a dearth of research gauging mucocutaneous and rheumatologic outcomes—the last studies focusing on mucocutaneous primary outcomes occurred in 2009, whereas the last studies focusing on rheumatologic primary outcomes occurred in 1998, the researchers noted.

“Extrapolating these trends forwards, this suggests a ‘plateau’ in new data generation for certain aspects of disease, with little new data likely to appear in the foreseeable future,” the researchers wrote.

Despite the focus on ocular outcomes, the highest quality research, according to the Scottish Intercollegiate Guideline Network hierarchy of evidence, was found in studies gauging mucocutaneous outcomes and rheumatologic outcomes.

Smaller sample sizes could have led to certain studies being excluded, the researchers noted. The disease’s rarity within the general population make the large sample pools needed for clinical studies unattainable for some clinicians. Despite this, the researchers called the research shortage for certain disease manifestations “alarming,” while also suggesting a reappraisal of older disease therapies.