This Week in Rheumatology — May 28, 2026

Welcome to This Week in Rheumatology. This week we're covering 9 notable papers spanning new therapeutic paradigms like CAR-T cell therapy [7], optimizing treatment in challenging populations like lupus nephritis [3] and elderly vasculitis [4], and innovations in diagnostics for conditions from myositis-ILD [8] to hand osteoarthritis [5]. We'll also touch on the growing global burden of mental health [9], a key comorbidity for our patients. Let's dive in.

First, we look at several papers outlining future directions for therapy, from cellular engineering to novel stromal targets.

A major review in *Nature Medicine* surveys the rapidly developing field of CAR-cell therapies for autoimmune diseases [7]. Initially developed for cancer, these engineered cells are now being used to achieve deep B-cell depletion and 'reset' the immune system. The review discusses key targets like CD19 and BCMA, summarizing the current evidence on efficacy and safety, and providing an outlook on what may become a transformative approach for severe, refractory autoimmune conditions.

On a more fundamental level, a study in *Science Translational Medicine* uncovers a mechanism that could open up new therapeutic avenues [1]. In ovarian cancer models, the authors found that tumor-intrinsic genomic instability activates a signaling pathway that leads to the secretion of WNT proteins. This, in turn, programs cancer-associated fibroblasts into an immunosuppressive lineage characterized by the protein POSTN. These specific fibroblasts then suppress anti-tumor immunity. The authors showed that therapeutically blocking POSTN could reinvigorate T-cell cytotoxicity. For rheumatology, this highlights POSTN as a potential stromal-specific checkpoint that could be targeted in diseases characterized by fibrosis and immune dysregulation.

Bringing these forward-looking concepts to current clinical strategy, a perspective piece in *Nature Reviews Rheumatology* argues for a formal treat-to-target, or T2T, approach in Behçet syndrome [6]. The authors note that while T2T is standard in many rheumatic diseases, its application in Behçet's has been less defined. They propose an evidence-based, organ-specific framework for setting treatment goals, defining remission and relapse, and establishing monitoring strategies. This represents a crucial step toward standardizing care and improving outcomes in this complex multisystem vasculitis.

Next, two studies from the journal *Rheumatology* offer practical insights on refining our current treatment approaches in lupus nephritis and ANCA-associated vasculitis.

First, a multicenter propensity-matched study provides strong support for the early use of belimumab in lupus nephritis [3].

The Study

Investigators compared patients who received belimumab plus standard of care as their initial therapy against a historical cohort who received standard of care alone.

Results

At 6 months, the rate of complete renal response was more than double in the belimumab group compared to the standard care group, at 36% versus 16.5%. This translated to a significantly shorter time to achieve a complete renal response. While response rates were similar by 12 months, a crucial finding was that patients in the belimumab group were on a significantly lower dose of glucocorticoids when they achieved their response. The authors conclude that early combination therapy with belimumab accelerates renal response and reduces glucocorticoid exposure, key goals in preventing long-term kidney damage.

In contrast, another paper in *Rheumatology* explores treatment in the challenging population of older patients with ANCA-associated vasculitis [4].

The Study

This was a retrospective review of hospitalized patients aged 75 years or older who were starting induction therapy for severe AAV.

Results

The study found that clinicians were already tailoring treatment based on age and frailty in the real world. For example, low-dose rituximab was favored for the oldest and most frail patients. Despite the advanced age and severe disease in this cohort, the one-year mortality rate was 20%. The authors suggest this rate, which is comparable to that seen in younger and less severe AAV cohorts, indicates that this individualized, frailty-guided approach may successfully mitigate some of the high risk associated with treating AAV in the elderly. However, serious infection requiring hospital readmission remained a significant concern, affecting about 27% of patients in the first year.

Our third theme covers new diagnostic technologies, from biomarkers and imaging for ILD to artificial intelligence for osteoarthritis and new approaches to genetic testing.

First, a study in *RMD Open* provides a practical, non-invasive model for screening and predicting interstitial lung disease, or ILD, in patients with idiopathic inflammatory myopathy [8].

Methods

Using high-resolution CT as the gold standard, investigators assessed the diagnostic performance of the serum biomarker KL-6 and lung ultrasound B-lines.

Results

They identified optimal cutoffs for screening. A serum KL-6 level of 553 U/mL or higher was found to be highly specific for ILD, at nearly 96%. A lung ultrasound B-line count of 25 or more was extremely sensitive, at almost 99%, making it an excellent tool to rule out ILD. The combination of the two markers yielded outstanding diagnostic performance, with an AUC of 0.984. The authors developed an online prediction model based on these findings, offering a valuable tool for early ILD identification.

Moving to the joints, a study in *Osteoarthritis and Cartilage* explores the use of radiomics—a form of AI analysis—for grading hand osteoarthritis on standard X-rays [5].

The Study

Researchers trained a machine learning model to automatically assess structural severity and predict Kellgren-Lawrence, or KL, grades from radiographs.

Results

The model showed good performance in distinguishing joints with structural damage (KL grade 2 or higher) from normal joints, and also in identifying severe disease (KL grades 3-4), with good sensitivity and specificity. While it had more difficulty distinguishing between intermediate grades, the study demonstrates the potential for radiomics to provide a more objective and automated method for scoring radiographic severity in hand OA, reducing the reliance on subjective visual grading.

Finally, a review in *Nature Reviews Rheumatology* addresses a common frustration in genetic testing: the variant of uncertain significance, or VUS [2]. Focusing on systemic autoinflammatory diseases, the article details how the field is moving beyond this diagnostic ambiguity. Advances in computational tools, including AI and protein structure prediction, are being combined with high-throughput functional assays that can test the effects of hundreds of variants at once. These integrated approaches are generating large datasets that improve our ability to accurately classify variants in genes like *NLRP3* and *MEFV*, leading to more definitive genetic diagnoses and better-informed treatment decisions.

Finally, we step back to look at a major public health issue with profound relevance for our patients: the global burden of mental health.

A landmark analysis from the Global Burden of Disease Study, published in *The Lancet*, provides updated trends on mental disorders from 1990 to 2023 [9].

The Findings

The numbers are staggering. In 2023, an estimated 1.17 billion people were living with a mental disorder globally. This represents a near doubling in the total number of cases since 1990, and a 24% increase in the age-standardized prevalence rate.

The Burden

In terms of health impact, mental disorders have climbed from the 12th to the 5th leading cause of global disability-adjusted life-years, or DALYs. Most strikingly, they are now the single leading cause of years lived with disability worldwide, accounting for over 17% of the total. For rheumatologists, this underscores the critical importance of screening for and addressing comorbidities like anxiety and depression, which are highly prevalent in our patient populations and significantly impact their overall health and quality of life.

If you only have time for one paper this week, make it the study on early belimumab in lupus nephritis by Gatto and colleagues in *Rheumatology* [3]. It provides compelling, real-world-style evidence that an earlier, more aggressive approach not only accelerates renal response but also facilitates crucial steroid sparing. This supports a shift in practice toward earlier integration of biologics in severe lupus nephritis, aligning with a key goal of preventing long-term damage.

Here are the key takeaways from this week in Rheumatology. First, in active lupus nephritis, consider adding belimumab to standard therapy from the outset. Propensity-matched data suggests this can accelerate complete renal response at six months and lower the cumulative glucocorticoid dose [3]. Second, for elderly and frail patients with severe ANCA-associated vasculitis, tailoring induction therapy based on a holistic assessment appears to be a valid real-world strategy. While infection risk remains high, this approach may mitigate the expected high mortality in this vulnerable group [4]. Third, for non-invasive screening of interstitial lung disease in patients with inflammatory myopathy, consider the combination of serum KL-6 and lung ultrasound. A KL-6 above 553 U/mL is highly specific, and a B-line count of 25 or more is highly sensitive. Together, they offer excellent diagnostic accuracy [8]. Finally, be aware of the immense and growing burden of mental health disorders. The latest Global Burden of Disease data confirms they are the leading cause of disability worldwide, reinforcing the need for routine screening and management of depression and anxiety in our patients with chronic rheumatic diseases [9].

That's your roundup for This Week in Rheumatology. The full transcript and references are available on the episode page in your AudioScholar library. This is an AI-curated summary — for clinical decisions, always consult primary sources and current guidelines. See you next week.