Psoriatic arthritis linked to interstitial lung disease prevalence

This systematic review and meta-analysis synthesized data from 14,272 patients with psoriatic arthritis to estimate the pooled prevalence of interstitial lung disease. The primary analysis found an overall prevalence of 3%, with a wide 95% confidence interval of 1% to 7% and very high heterogeneity (I² = 96.6%). This high heterogeneity suggests significant variability across included studies, which may be influenced by differences in diagnostic criteria and population characteristics.

When stratified by diagnostic method, prevalence estimates varied substantially. Studies using imaging-based identification reported a higher prevalence of 6% (95% CI: 4%-10%; I² = 55%), while those relying on non-imaging methods found a much lower prevalence of 1% (95% CI: 1%-11%; I² = 0%). These findings highlight the critical impact of diagnostic approach on reported prevalence rates.

A key secondary outcome identified smoking as a significant risk factor for interstitial lung disease in this population. The pooled odds ratio was 2.94 (95% CI: 1.22-7.12), indicating that smoking is associated with nearly three times the odds of developing interstitial lung disease compared to non-smokers. This association underscores the importance of smoking cessation in managing psoriatic arthritis.

The meta-analysis included only observational studies, and the authors caution that these findings report associations, not causation. The high heterogeneity in the primary prevalence estimate further limits the certainty of the pooled result. Subgroup analysis by diagnostic method showed lower heterogeneity for imaging-based studies, suggesting that diagnostic methodology is a major source of variability.

From a clinical practice perspective, interstitial lung disease may be underrecognized in routine care for psoriatic arthritis patients. Increased awareness and standardized diagnostic approaches are needed to improve detection and management. However, the authors do not recommend specific screening or management strategies based solely on this review, given the observational nature of the data and high heterogeneity.

Limitations of the review include the lack of detailed reporting on study settings, interventions, and comparators. The funding sources and potential conflicts of interest were not reported, which may introduce bias. Despite these limitations, the review provides valuable epidemiological data on a potentially serious comorbidity in psoriatic arthritis.

In conclusion, this meta-analysis estimates that approximately 3% of psoriatic arthritis patients have interstitial lung disease, with higher prevalence when using imaging-based diagnosis. Smoking is a modifiable risk factor that significantly increases the odds of ILD. Clinicians should maintain a high index of suspicion for ILD in psoriatic arthritis patients, particularly smokers, and consider appropriate diagnostic evaluation.