The edition · Rheumatology
Where the disease activity sits at week 12 tells you more than how fast it fell
A registry of 843 patients on JAK inhibitors gives a numerical threshold for the twelve-week decision; macrophage activation in lupus looks nothing like macrophage activation in Still's disease; and a probiotic trial in juvenile arthritis found more inflammatory signal, not less.
The edition in brief
Today's rheumatology edition opens with macrophage activation syndrome, where a nine-centre cohort shows the lupus-associated form diverges sharply from the Still's disease form. Still's-associated cases followed the expected hyperinflammatory pattern — marked hyperferritinaemia, very high C-reactive protein, organomegaly and liver injury, all meeting 2016 classification criteria. Lupus-associated cases showed more central nervous system dysfunction, less liver injury, deeper cytopenias and a strong autoimmune haemolysis signal, with 73% direct antiglobulin positivity, and interleukin-1 blockade in seven patients produced no rapid resolution. The regulatory sweep carries a supplement to the biologics licence for AVTOZMA, Celltrion's tocilizumab-anoh biosimilar, approved on 2 September 2026. The PERMAJI trial randomised 44 children with juvenile idiopathic arthritis to a probiotic or placebo alongside standard therapy: ACR Pedi 30 response was 47% against 63% (P = 0.33), worst-case imputation gave 36% against 68% (P = 0.03), and faecal Toll-like receptor 4 agonist activity rose on the probiotic. From the ANSWER cohort of 1,423 treatment courses, an early rheumatoid factor fall of at least 20% at three months was independently associated with twelve-month remission (adjusted odds ratio 1.39), with Janus kinase inhibitors producing the largest declines. The practice-changer is a trajectory analysis of 843 patients on Janus kinase inhibitors, giving Clinical Disease Activity Index thresholds of 12.0 at week 4 and 9.3 at week 12 for predicting a favourable year — with the absolute score outperforming the rate of change.
Macrophage activation in lupus is a different illness
In a lupus patient with new central nervous system features and deepening cytopenias, screen for haemolysis and check ferritin — macrophage activation here looks nothing like the Still's disease picture you were taught.
Another tocilizumab biosimilar supplement clears the FDA
A licence supplement for an existing tocilizumab biosimilar — nothing changes in what you can prescribe today, and the Indian position is set by CDSCO, not this record.
A probiotic that raised the inflammatory signal
Probiotics did not improve disease activity in juvenile idiopathic arthritis and raised a pro-inflammatory microbial signal — there is no basis for recommending them and no basis for calling them harmless.
A falling rheumatoid factor at three months is a good sign
Measure rheumatoid factor again at three months after starting a biological or targeted synthetic drug — a fall of 20% or more supports staying the course, though the disease activity score remains what you act on.
Count the joints even when you are sure
Do the joint count rather than estimating it, and record the patient global even when it contradicts your examination — the value of the score is the comparison with last visit.
CDAI 9.3 at twelve weeks is the number to decide on
At the twelve-week review on a Janus kinase inhibitor, act on where the Clinical Disease Activity Index sits — around 9.3 or below predicts a favourable year — rather than on how much it has fallen.
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