Prior antimalarial use did not change biopsy findings in lupus nephritis

Design

Retrospective analysis of a single-centre lupus cohort

Population

165 patients with biopsy-proven lupus nephritis

Primary outcome

Renal histology class, activity and chronicity indices

Effect

No detectable association with antimalarial exposure

A study from the University of Toronto Lupus Clinic (Rheumatology, 9 October 2026) examined 165 patients with biopsy-proven lupus nephritis, half of whom were taking an antimalarial before the biopsy.

After adjustment, antimalarial use was not associated with differences in proliferative class, NIH activity or chronicity indices, or interstitial fibrosis and tubular atrophy. Requiring six months or a year of continuous use gave the same answer.

This does not argue against hydroxychloroquine, whose benefits in lupus are well established beyond the kidney. It does suggest that a patient on an antimalarial should not be assumed to have milder renal histology, and that the threshold for biopsy should not shift because of it. The sample is small and a modest effect cannot be excluded.

• Continue hydroxychloroquine in lupus nephritis unless contraindicated
• Do not assume milder renal histology because a patient is on an antimalarial
• Keep the usual threshold for kidney biopsy regardless of antimalarial use

Why it matters

It removes a reason some clinicians use to defer a biopsy.

Don't overread it

A small single-centre study - it does not question hydroxychloroquine's role in lupus.

The statistics, in plain English

With 165 patients, the study could detect only fairly large differences. 'No detectable difference' is compatible with a modest protective effect that was too small to see.

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