Objective:

 To identify the main factors associated with diagnostic delay in IgG4-related disease (IgG4-RD) in Latin America, using the 2019 ACR/EULAR classification criteria.

Background:

IgG4-RD is a systemic fibroinflammatory disorder that can mimic infections, malignancies, and autoimmune diseases. Although the 2019 ACR/EULAR criteria established diagnostic standards, they do not encompass the full spectrum of IgG4-RD phenotypes, potentially leading to underdiagnosis and delays in recognition—particularly in resource-limited settings.

Design/Methods:

A systematic review was conducted following PRISMA guidelines. PubMed and ScienceDirect databases were searched for studies published between 2021 and 2025 addressing IgG4-RD diagnosis in Latin America. Eligible designs included clinical trials, cohort studies, original articles, and case reports. Two reviewers independently applied inclusion criteria and extracted data regarding diagnostic time, demographic features, and criteria compliance.

Results:

Of 248 screened records, five studies met inclusion criteria. The mean diagnostic delay was 12 months. Initial diagnostic suspicion was low (<20%), with many cases initially misclassified as malignancies or infections, reflecting the disease’s clinical heterogeneity and limited regional recognition. Latin American cases showed a higher female predominance and broader age range than reported globally. Notably, 40% of clinically diagnosed patients did not meet the 2019 ACR/EULAR criteria, largely due to unifocal or atypical organ involvement. Limitations in histopathological and serologic resources contributed significantly to delayed or missed diagnoses.

Conclusions:

Diagnostic delay in IgG4-RD across Latin America is multifactorial, driven by atypical presentations, under recognition, and restricted diagnostic infrastructure. Current criteria may not fully capture regional disease variability. These findings underscore the need for multidisciplinary collaboration, context-adapted diagnostic strategies, and epidemiological studies to improve early recognition and management of IgG4-RD in low- and middle-income countries.