Kicking a long-held clinical assumption, new population and genetic data suggest gout is turning up in rheumatoid arthritis far more often than thought, especially in seronegative disease.
Gout may be twice as common in people with rheumatoid arthritis as previously assumed, according to new research that challenges a long-standing teaching in rheumatology.
The new population and genetic data have been published in Arthritis Research & Therapy.
“Rheumatoid arthritis (RA) and gout are common inflammatory diseases, but their coexistence remains controversial given their distinct clinical and pathological characteristics,” the researchers wrote.
“RA is primarily characterized by autoimmune-driven synovitis and symmetrical polyarthritis, whereas gout results from hyperuricemia-induced monosodium urate (MSU) crystal deposition and typically presents with acute, episodic arthritis.
“However, increasing documentation of coexisting cases has raised doubts about the long-held belief that RA and gout rarely coexist.”
The researchers said although it was still considered uncommon, this coexistence may be “more frequently under-recognised than truly rare”.
“In addition to overlapping clinical presentations that complicate diagnosis, early immunologic studies proposed that rheumatoid factors (RF) may interact with MSU crystals to dampen neutrophil activation and reduce crystal-induced inflammation, thereby masking classical gout features in RA patients,” they wrote.
Using US NHANES data from 2007 to 2018 (n=19,705), the investigators found gout was reported in 10.3% of people with RA compared with 4.8% of propensity-matched controls.
The gap held even after balancing for age, sex, BMI, hypertension, CKD, diabetes, hyperuricaemia, smoking, alcohol, diuretic use and socioeconomic measures.
The researchers said this supported RA itself as an independent risk factor for gout (adjusted OR 2.67; 95% CI 1.95–3.67).
More strikingly, gout prevalence in RA rose across the survey cycles, from 7.7% in 2007-08 to 14.4% in 2017-18, while rates in the non-RA population stayed largely flat.
The researchers speculated that the coexistence of the diseases may appear rare because the signs were masked.
For example, steroids and NSAIDs could blunt classic crystal-flare theatre; DMARDs may shift urate biology; and RA’s inflammatory milieu may reshape how gout declares itself.
The NHANES findings also pushed against a comfortable shortcut, assuming serum urate would behave predictably in RA, they wrote.
Their analyses highlighted a shared interferon-signature: 207 overlapping RA–gout genes enriched in interferon signalling, immune activation and antiviral defence pathways, with five hub interferon-stimulated genes (RSAD2, DDX60, IFIT1, IFIT3 and XAF1).
They frame this as evidence of convergent immune circuitry, an overlap that might help explain why the two conditions can coexist.
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The study has several limitations. The cross-sectional NHANES data limit causal inference and may be affected by recall bias and residual confounding, meaning the nonlinear relationship between serum urate and gout in RA could reflect unmeasured factors.
Mendelian randomisation analyses also used relatively few genetic instruments, particularly for seronegative RA, which may reduce statistical power and introduce weak-instrument bias.
Although MR suggested a causal effect of RA, especially seronegative RA, on gout, it did not support a causal link with serum urate, indicating other pathways may be involved.
Results were also largely limited to European ancestry populations. Finally, transcriptomic analyses used small GEO datasets without independent validation, making them vulnerable to technical variability.
“Future studies should include longitudinal urate profiling in RA, larger and ethnically diverse genetic datasets, and experimental validation to better clarify the interplay between RA, SUA, and gout risk,” the researchers wrote.
They said RA complicated by gout was becoming more common, particularly in men over 60, although the mechanisms remained unclear.
“Collectively, they indicate an underappreciated overlap and support more targeted screening and management in RA populations, while highlighting the need for further exploration of the underlying mechanisms,” the researchers concluded.
