May 2026 Research Update

Across these studies, long-term control with biologic medicines was generally maintained for many people, but not everyone stayed on the same plan without flare-ups. The strongest signals were about practical treatment approaches (such as switching injection format or attempting less frequent dosing) and how often people were able to continue treatment over time in real-world care. Because these were retrospective (looking back at records) and often small in specific subgroups, they cannot prove what will happen for any individual person. [1] [2] [3]

In a multicenter Italian cohort across several immune-mediated inflammatory diseases (including Behcet disease), subcutaneous infliximab CT-P13 was continued by about two-thirds of patients at 18 months, and overall disease activity improved with relatively few serious adverse events reported. People who switched from intravenous infliximab tended to stay on the subcutaneous form longer than people starting infliximab in this format for the first time. [1]

In a small Italian series of 10 adults with Behcet disease who were stable on intravenous infliximab, most stayed in remission after switching to subcutaneous infliximab during a median follow-up of 15 months, but 2 people relapsed and returned to intravenous treatment. Prednisone use decreased, infections were reported in 3 people, and patient-reported experience with self-injection was generally positive. [2]

In a Japanese cohort of 83 people with non-infectious uveitis (including Behcet-related uveitis as one of the causes studied), adalimumab treatment was linked to lower oral steroid use and better vision on average, and many reached inactive eye inflammation at 12 months. However, when 24 people tried spacing out adalimumab doses, more than half relapsed, suggesting that less frequent dosing may not work for everyone. [3]

For patients and caregivers, this set of studies mainly adds real-world information about living with long-term biologic therapy, including convenience (self-injection), staying on treatment, and the possibility of flare-ups with certain changes like dose spacing. The Behcet-specific infliximab switch data are based on a small number of patients, so the relapse and infection rates may not reflect what would be seen in larger groups. For uveitis, the results suggest many people can reduce steroid exposure on adalimumab, but it remains uncertain who can safely space doses without relapse. [1] [2] [3]

This study looked at a care approach around hydroxychloroquine: baseline eye screening. In a nationwide South Korean claims dataset, only about one-third of adults starting hydroxychloroquine had a recorded eye exam within 12 months, and those who did were somewhat more likely to remain on hydroxychloroquine longer. Because this was based on billing records, it cannot fully separate planned screening from tests done because of symptoms, and it does not show whether screening prevents side effects. [4]

People who had baseline screening, including optical coherence tomography (a type of detailed eye scan), had a modestly lower chance of discontinuing hydroxychloroquine during follow-up compared with people without recorded screening. Behcet disease was one of the diagnoses linked with higher likelihood of getting baseline screening, while taking certain other immune medicines was linked with lower screening rates. [4]

For patients, this research is mostly about how care is delivered rather than whether hydroxychloroquine works for Behcet disease. The main takeaway is that baseline eye checks were not consistently documented in this health system, and having them recorded was linked to staying on the medication longer, though the reason for that link is uncertain. This study does not tell whether any individual needs screening or how often, and it does not measure eye outcomes directly. [4]

Across studies, Behcet's disease did not look the same for everyone: risk of future organ involvement differed by basic factors (sex and age at onset), genetics (HLA-B51), and early symptom patterns (types of mouth ulcers and certain skin findings). The clearest signals were that males and people with earlier onset more often had eye, blood vessel, and nervous system involvement, and that particular ulcer patterns helped predict later bowel involvement. [5] [6]

In a single-center analysis of 4007 people, males more often had eye, blood vessel, and nervous system involvement, while females more often had joint involvement. Earlier-onset disease (before age 16) was linked to a broader spread of organ involvement, and smoking was linked to higher blood vessel involvement in multivariable analyses. [5]

In a registry cohort of 328 people who started with only mouth/skin symptoms, 14% later developed intestinal (bowel) involvement. Major mouth ulcers were the strongest predictor of later bowel involvement, while having only minor mouth ulcers (without major ones) was linked to lower bowel risk; certain combinations (major mouth ulcers plus genital ulcers and/or pseudofolliculitis) raised risk further. [6]

In that same registry study, bowel involvement was also linked to higher odds of eye inflammation, suggesting that these two forms of organ involvement can occur together in some patients. The study also reported signals that HLA-B51 positivity and Caucasian ethnicity might raise bowel risk, but estimates were less certain because of subgroup sizes. [6]

For patients and caregivers, these results help explain why follow-up plans often differ between people: early symptoms (like major vs minor mouth ulcers), age when symptoms began, sex, and sometimes genetics can line up with different patterns of organ involvement. What remains uncertain is how well these patterns predict outcomes for an individual person, since some results come from single centers or registries and may not fully capture differences in treatment or length of follow-up. [5] [6]

Several studies looked at risk in the broader population and in specific life situations rather than day-to-day symptom prediction. Overall, they suggest that certain events or starting points (pediatric uveitis, recent COVID-19 infection, and pregnancy loss history in women with Behcet's disease) can be markers of higher likelihood of immune-mediated disease or heavier systemic involvement, but these studies cannot prove cause and effect. [7] [8] [9]

In a nationwide Korean cohort of 27,656 children and adolescents with new noninfectious uveitis, the 5-year cumulative incidence of developing an immune-mediated inflammatory disease was 8.52%. Behcet's disease was one of several conditions diagnosed after uveitis, and the relative risk versus the general population was higher overall, with differences by age and sex. [7]

In a South Korea nationwide analysis using claims and a time-based method (sequence symmetry analysis), COVID-19 infection was followed by higher rates of several new-onset autoimmune diagnoses within the study window, including Behcet's disease. The same pattern was reported even in non-severe COVID-19, and bowel-related autoimmune diseases were also higher in that subgroup. [8]

In a retrospective cohort of 114 women with Behcet's disease, a history of pregnancy loss was linked to more gastrointestinal involvement and more eye involvement, and it was also linked to higher disease activity scores. The authors noted important limits, including the single-center, retrospective design and unadjusted (univariable) analyses. [9]

Two additional epidemiology-focused studies add context about who is affected and how outcomes vary by disease type. In Sardinia (Italy), linking multiple health data sources estimated a 2016 Behcet's syndrome prevalence of 11.7 per 100,000 and highlighted that case counts can change depending on which criteria and databases are used. In a single-center pediatric rare-vasculitis cohort (not limited to Behcet's disease), remission was common overall, but some vasculitis types had slower remission and more long-term damage, showing why long-term outcomes can vary widely across different vasculitis diagnoses. [10] [11]

This theme is mainly background for understanding risk and long-term outlook at a group level. The uveitis and COVID-19 studies show higher rates of later immune diagnoses in large datasets, but they rely on administrative records and limited time windows, so they cannot tell what will happen to any one person. The pregnancy loss study suggests pregnancy history may sometimes reflect a higher overall disease burden in Behcet's disease, but it was exploratory and needs confirmation in larger, adjusted studies. [7] [8] [9]

Across these studies, researchers looked for measurable signals in blood or imaging that line up with Behcet's disease activity in specific organs, especially the eyes and blood vessels. Several blood markers were higher when eye inflammation was active, and one immune marker was higher in people with vascular involvement, while a lung blood vessel scan described patterns seen in Behcet's-related vessel inflammation. Overall, the direction of results was consistent (more inflammation markers with more active disease), but the work was mostly small and exploratory, so it is not yet clear how well these tests would perform in everyday care. [12] [13] [14] [15]

For eye involvement (uveitis), one cross-sectional study found that several blood vessel lining (endothelial) markers were higher during active uveitis, while Ang-1 was lower. Higher levels of some of these markers tracked with worse vision measurements in that active uveitis group, and two markers (EphB4 and EphrinB2) separated active uveitis from no eye involvement with high accuracy in this dataset. [12]

A separate case-control study tested a combined blood-count inflammation score (pan-immune-inflammation value) and related ratios from routine blood cells. These values were higher in Behcet's disease than in healthy controls, and the combined score increased with higher disease activity scores and a standard inflammation test (erythrocyte sedimentation rate); it was also higher when ocular or joint symptoms were active. In this study, the combined score had moderate ability to flag active ocular involvement based on a chosen cutoff. [13]

For vascular involvement, one clinical study reported that the immune marker EBI-3 was higher in Behcet's disease with vascular involvement than in Behcet's disease without vascular involvement and healthy controls, with good separation in its receiver operating characteristic analysis. In the same work, nitric oxide, IL-6, and IL-32 were higher in Behcet's disease than in controls, while several other measured cytokines did not differ. [14]

For lung blood vessel assessment, a retrospective imaging study used optical coherence tomography (a high-resolution catheter-based scan) to describe different patterns across several diseases that can affect the lung arteries. In Behcet's disease (and Takayasu arteritis), the authors described bead-like, off-center thickening of the vessel lining with small vacuole-like changes, suggesting this scan may help describe lesion type in selected patients undergoing invasive evaluation. [15]

For patients and caregivers, this set of studies mainly adds background about possible future ways to track Behcet's disease activity in specific organs, especially the eyes and blood vessels, using blood tests or specialized imaging. The uncertainty is how these markers perform over time (not just at one visit), how much results vary with medications or other conditions, and whether they improve on existing clinical exams and standard lab tests; larger, repeated-measurement studies are needed to confirm usefulness and define practical roles. [12] [13] [14] [15]

One retrospective study reviewed kidney biopsies in adults with several non-lupus rheumatic diseases to see which kidney tissue diagnoses were most common. While amyloid was the most frequent overall diagnosis across all diseases, the pattern differed by underlying condition, and Behcet's disease had a high proportion of focal segmental glomerulosclerosis (scarring in parts of the kidney filters) among those biopsied. Because this is a biopsy-based hospital cohort, it reflects people who had enough concern to undergo biopsy and may not represent all patients with Behcet's disease. [16]

Across the full group, the most common reason for biopsy was blood in the urine with low-grade protein in the urine, and the most common tissue diagnosis was amyloidosis, followed by focal segmental glomerulosclerosis. In disease-specific results, focal segmental glomerulosclerosis was reported most often in Behcet's disease compared with other rheumatic conditions in this series. [16]

This study is most relevant as context for understanding that, when kidney issues occur in rheumatic diseases, the underlying cause can vary by condition and may require tissue diagnosis in selected cases. For Behcet's disease, the biopsy pattern in this series emphasizes that kidney findings are not all due to one process (such as amyloid), but it does not show how often kidney disease occurs in the broader Behcet's population or how biopsy results change monitoring in routine care. [16]

This months papers showed that blood vessel involvement in Behcet's disease is not rare in clinic populations and can take several forms, from deep vein clots to artery problems and, less commonly, direct heart involvement. Across reports, immune-driven inflammation remained a key theme, and treatments aimed at calming the immune system were repeatedly part of management, while outcomes varied widely depending on the situation. [17] [18] [19] [20]

In a retrospective cohort from Qatar that included 82 people, 17 had confirmed vascular involvement (20.7%), and venous disease was the most common pattern. In that cohort, using immunosuppressive therapy with corticosteroids was linked to fewer relapses, while anticoagulation alone did not appear to reduce relapses. [17]

Several case reports highlighted how Behcet's disease can show up with clotting in or near the heart and lungs. One 26-year-old man had a clot inside the right side of the heart along with blood clots in both lungs, and he improved after receiving both anticoagulation and immune-suppressing treatment. [18]

Artery involvement was illustrated in a 23-year-old man who had Budd-Chiari syndrome (blocked blood flow out of the liver) and a pseudoaneurysm in a coronary artery. He was treated with a heart artery procedure using stents (including a covered stent) followed by immunosuppressive therapy, with significant improvement during follow-up. [19]

A more severe outcome was described in a 32-year-old man with Behcet-like features who had pulmonary artery thrombosis and a mass attached to the tricuspid valve that proved to be an inflammatory organizing hematoma. Despite anticoagulation and valve replacement, he developed pulmonary artery pseudoaneurysms and died from fatal bleeding, raising the possibility of overlap with Hughes-Stovin syndrome in this presentation. [20]

One translational lab-and-patient study connected immune cell behavior to blood vessel damage in Behcet's disease. It reported that a subtype of neutrophils (CD177+ cells) made more web-like traps that were enriched in a specific histone (H3.1), and these traps drove blood vessel lining cells toward an aged, inflamed state through a TLR4 pathway, which could attract more neutrophils and potentially feed ongoing vessel inflammation. [21]

For patients and caregivers, these studies reinforce that vascular Behcet's disease can range from more common vein clots to less common but serious involvement of arteries, the lungs, and the heart, sometimes presenting with symptoms like chest pain, shortness of breath, or coughing blood. The strongest practical information this month comes from the clinic cohort suggesting fewer relapses when immune-suppressing treatment was part of care, while the lab study mainly adds background on why blood vessel inflammation may persist. Important uncertainties remain because several reports describe only one patient, and rare complications (like pulmonary artery pseudoaneurysms and bleeding) are hard to predict from small numbers. [17] [18] [19] [20] [21]

Across two small retrospective studies from specialty centers, nervous system involvement in Behcet's disease most often affected the brain tissue (parenchymal disease), frequently in the brainstem, and could show up as balance or coordination problems, headache, or changes in behavior. Relapses were reported in one cohort, meaning symptoms returned or worsened after improving. Overall, the direction of results suggested many patients improved over follow-up when treated with steroid-based approaches, though some needed escalation to additional immune-suppressing therapies. [22] [23]

In an Indian chart review of 12 Neuro-Behcet patients (all male), brain tissue involvement and brainstem involvement were each seen in 75% of patients, and movement problems were common, especially cerebellar ataxia (coordination and balance difficulty). Over a median 15 months of follow-up, relapses occurred in 58.3%, while 83.3% had clinical improvement; many required additional immune-suppressing treatment over time. Treatment most often included intravenous steroids, and some patients also received plasma exchange, azathioprine, or rituximab. [22]

In a tertiary uveitis center study, 12 people with Behcet uveitis developed Neuro-Behcet syndrome during follow-up, representing 4% of the clinic's Behcet uveitis cohort. Parenchymal involvement was most common, and neuropsychiatric symptoms were reported in 41.7%; headaches and behavioral changes often appeared before clearer neurologic deficits, and imaging changes could sometimes be present without obvious symptoms. Care often required escalation of systemic therapy (including pulse steroids and biologics), and at final follow-up visual acuity was stable with no permanent neurologic after-effects reported in this series. [23]

For patients and caregivers, these reports help describe what nervous system Behcet can look like in real-world specialty clinics, including balance/coordination symptoms and neuropsychiatric changes, and they show that follow-up may involve watching for relapse or new symptoms over time. Because both studies were small and retrospective (looking back at charts), they cannot predict what will happen for any one person, and they may not represent all ages, sexes, or care settings. The studies mainly add background context about symptom patterns, imaging involvement (often brainstem), and the range of immune-suppressing treatments used in practice, while leaving uncertainty about how common these patterns are in broader populations.

Across these studies, researchers used single-cell gene activity maps to look at immune behavior in Behcet's disease, both in blood and in gut tissue. A consistent message was that Behcet's shares some immune changes seen in other rheumatic diseases, but also shows Behcet's-specific patterns in how certain immune cells act and communicate. Because these are exploratory single-cell studies, they describe biological patterns rather than proving cause and effect. [24] [25]

In an integrated analysis of public blood datasets, gamma-delta T cells showed reduced functional activity across five rheumatic diseases compared with healthy controls, suggesting a shared type of T cell dysfunction. In Behcet's disease specifically, monocytes and macrophages showed higher gene signatures linked to cytotoxicity and phagocytosis, and the study highlighted differences in T cell to myeloid cell communication involving MIF and GALECTIN signaling compared with other diseases. The authors noted key limits, including that the work was blood-only and lacked protein-level validation. [24]

For patients, this work mainly adds background about which immune cells and communication pathways may be involved in Behcet's disease, and how some patterns overlap with other rheumatic conditions. It does not change day-to-day care, and it cannot by itself tell which specific immune changes drive symptoms. The findings may help guide future research into targeted ways to measure or influence immune signaling, but that next step was not tested here. [24]

In intestinal Behcet's disease, these data suggest that inflammation is not only about immune cells, but also involves the supporting tissue structure in the gut wall. The overall pattern pointed to activated stromal cells and remodeling of the extracellular matrix in inflamed areas, along with predicted communication between blood vessel lining cells and neutrophils. Because this was based on gene activity in a very small number of biopsies, it should be viewed as an early map of possible mechanisms rather than a confirmed pathway. [25]

Researchers analyzed paired inflamed and histologically normal terminal ileum biopsies from four people with active intestinal Behcet's disease and compared the results with public Crohn's disease and healthy control datasets. They reported robust stromal activation and extracellular matrix remodeling in inflamed tissue, and they described epithelial antimicrobial signatures that may be distinct from Crohn's disease patterns reported in the comparison datasets. They also predicted harmful crosstalk between endothelial cells and neutrophils mediated by collagen or laminin binding to CD44. [25]

For people affected by intestinal Behcet's disease, this study suggests that gut tissue remodeling and blood vessel to immune-cell interactions may be part of what is happening during active inflammation, beyond general immune activation alone. However, the work was based on four patients and on predicted cell-to-cell signaling from gene data, so it cannot confirm which interactions truly drive flares or which would be useful to target. Its main value right now is helping researchers prioritize what to test in larger tissue studies and in experiments that can confirm these pathways at the protein and tissue-function level. [25]

Across these papers, the main pattern is that Behcet-like symptoms (especially mouth and genital sores) can be caused by very different conditions, and the correct diagnosis depended on specific tests rather than symptom patterns alone. One report highlights skin and mucosal biopsy with a specialized staining test, while the other focuses on genetic testing in a family with a Behcet-like autoinflammatory syndrome. Both are case reports, so they illustrate possibilities rather than how often these mimics occur. [26] [27]

In one patient, painful mouth and genital ulcers were repeatedly labeled as infections and then Behcet's disease, but later testing pointed to pemphigus vulgaris, an autoimmune blistering disease that can mainly affect mucous membranes. A biopsy and direct immunofluorescence (a lab test that looks for immune proteins in tissue) supported this diagnosis, and the report describes sustained improvement after treatment directed at pemphigus vulgaris. This single-person report underlines how tissue testing can change the explanation for persistent ulcer-like sores. [26]

In a separate family report, genetic testing identified a new (de novo) change in the RELA gene in a person with Autosomal Dominant Familial Behcet-like Autoinflammatory Syndrome type 3. Parental testing showed the variant was not inherited, and the authors classified it as likely disease-causing in this context. This illustrates that, for some people with Behcet-like inflammation, a single-gene cause may be identifiable through genetic testing. [27]

For patients and caregivers, these reports are mainly background information about why Behcet's disease can be difficult to distinguish from other conditions when symptoms overlap. They show that different kinds of tests (for example, examining a tissue sample with immune staining, or looking for a genetic cause in a Behcet-like syndrome) can sometimes clarify what is driving mouth or genital sores. What remains uncertain is how commonly these specific mimics occur in routine care, because both papers describe only one patient or one family.