AB1061 2019 ACR/EULAR CLASSIFICATION CRITERIA FOR IGG4-RELATED DISEASE IN RUSSIAN COHORT OF PATIENTS.

Abstract

Background:IgG4-related disease (IgG4-RD) is a systemic immunomediated fibroinflammatory condition that can affect almost any organ in the body. This is the reason for dramatic variety of clinical symptoms and complexity of diagnostics. 2011 Comprehensive diagnostic criteria (CDC) for IgG4-RD are used to establish the diagnosis for all lesions (except autoimmune pancreatitis type 1). In 2019 the new ACR/EULAR classification criteria for IgG4-RD were proposed to facilitate the formation of more homogenous groups of patients primarily for clinical trials inclusion purpose. They also provide a framework for clinicians considering diagnosis of IgG4-RD.Objectives:To evaluate 2019 ACR/EULAR classification criteria for IgG4-RD in Russian cohort of patients with IgG4-RD.Methods:59 patient with IgG4-RD according to CDC with biopsy proven diagnosis were included.Results:The mean number of affected organs was 2.1; 31 patients (52,5%) were women. Majority of patients had sialoadenitis (25 patients) and/or orbital disease (31 patients), 9 had retroperitoneal fibrosis (RPF). Other affected organs were lungs, pancreas, lymph nodes, paranasal sinuses, thyroid and low urinary tract. Twenty five (25) patients (42,4%) had definite, 14 (23,3%) probable and 20 (34,3%) possible diagnosis of IgG4-RD. Twenty three (23) patients (39%) didn’t fulfill the 2019 ACR/EULAR classification criteria for IgG4-RD. Among them were the majority of patients with RPF (7 patients) who were lacking other organ involvement and IgG4 hypersecretion either in the tissue or serum. The majority of excluded cases were due to inadequate pathomorphological evaluation (lacking of the exact number and percentage (if >40%) of IgG4+ cells), lacking of multi-organ involvement or different patterns of involvement, e.g. in case of lungs involvement.Conclusion:The new 2019ACR/EULAR classification criteria for IgG4-RD are very useful in evaluation of typical organ involvement and systemic course of IgG4-RD. It is essential to adjust Russian pathomorphologists’s approach to cell counting and percentage determination for IgG4-RD cases to get suitable protocols.Disclosure of Interests:None declared