Environmental exposures in autoimmune inflammatory rheumatic diseases: a priority-based evidence map, immune-mechanism integration audit and research agenda

Introduction Environmental exposures have been hypothesised to influence immune tolerance, but human studies of autoimmune inflammatory rheumatic diseases (AIRDs) often report exposure–disease associations without measuring immune intermediates. We mapped the structure, directionality, immune-mechanism integration and research priorities of this literature. Methods Web of Science Core Collection and Scopus were searched on 18 May 2026 for English-language article/review records published during 2005–2025; non-original publications were excluded during eligibility assessment. Of 12,497 deduplicated records screened at title/abstract level, a predefined prioritisation strategy selected 2,632 reports for focused coding. Four high-density exposure–AIRD cells underwent SWiM-aligned direction-of-effect synthesis and focused OHAT-style risk-of-bias assessment, 64 cells underwent consensus research-priority scoring, and a post hoc four-level audit assessed immune-mechanism integration. No pooled effect estimates were calculated because exposures, outcomes, designs and analytical approaches were heterogeneous. Results Of 17,089 records before deduplication, 433 studies were included. Smoking/tobacco exposures dominated (n = 215, 49.7%), and rheumatoid arthritis was the most studied AIRD (n = 254, 58.7%). Twenty-five studies (5.8%) directly measured a pathway-proximal intermediary or omics readout, 79 (18.2%) measured an immune, serologic, complement or inflammatory biomarker, and 266 (61.4%) did not integrate an immune endpoint. Among 199 classifiable study-cell entries in four dense cells, mixed (n = 93) and positive/harmful (n = 91) directions were nearly balanced. Alternative priority-scoring schemes showed high rank concordance, and smoking/tobacco × systemic sclerosis remained within the top three priorities. Discussion This priority-based evidence map identifies a large but uneven association literature with limited direct immune-mechanism integration and supports more rigorous exposure assessment, immune phenotyping, mixture-aware analyses and geographically diverse research.