Rheumatology

ICI-IA versus ICI-PMR: phenotype, age, and second-line therapy differ

In a multicenter prospective registry of 490 patients, 418 had ICI-related inflammatory arthritis (ICI-IA) and 72 had ICI-PMR. Patients with ICI-PMR were older (median 70 vs 63 years), more often male, and had much less peripheral synovitis (15% vs 72%). Time to prednisone taper and progression-free survival were similar between groups, but ICI-IA had higher second-line immunosuppressive use (adjusted OR 3.51, 95% CI 1.50–8.21). Clinical trials and treatment plans for ICI rheumatic toxicity should stratify by phenotype because treatment intensity differs. 1

Racial minorities under-represented in SLE randomized trials (2014–2024)

Systematic review of 63 SLE RCTs found White participants comprised 61% of trial enrollees, with Black and Asian participants each at 14% and Indigenous at 8%. Overall trial participants were predominantly female (91%), and Hispanic/Latino reporting was inconsistent across studies. The data indicate limited representation of key minority groups relative to disease epidemiology, risking reduced generalizability. Trial designers and reviewers should prioritize diverse enrollment and transparent race/ethnicity reporting in SLE RCTs. 2

Ambient particulate matter and extreme cold days raise incident arthritis risk

Prospective cohorts of 13,147 Chinese adults ≥45 years without baseline arthritis found each 1 µg/m³ increase in PM1 associated with HR 1.061 (95% CI 1.030–1.093) for incident arthritis. Each additional extreme low-temperature day conferred HR 1.042 (95% CI 1.019–1.065), and a weighted mixture index (PM + LTD) showed HR 1.719 (95% CI 1.379–2.143). Dose-response analyses suggested nonlinear and threshold effects for several PM fractions and extreme weather variables. Consider environmental exposures as modifiable risk factors in population counseling, noting study population was middle-aged and older Chinese adults. 3