Performance of the 2019 ACR/EULAR classification criteria for IgG4-related disease and clinical phenotypes in a Spanish multicentre registry (REERIGG4).

OBJECTIVES: Several IgG4-related disease (IgG4-RD) phenotypes have been proposed and the first set of classification criteria have been recently created. Our objectives were to assess the phenotype distribution and the performance of the classification criteria in Spanish patients as genetic and geographical differences may exist. METHODS: We performed a cross-sectional multicentre study (Registro Español de Enfermedad Relacionada con la IgG4, REERIGG4) with nine participating centres from Spain. Patients were recruited from November 2013 to December 2018. The 2019 American College of Rheumatology/European League Against Rheumatism classification criteria (AECC) were used. RESULTS: We included 105 patients; 88% had Caucasian ethnicity. On diagnosis, 86% met the international pathology consensus while 92% met the Japanese comprehensive criteria. The phenotype distribution was head and neck 25%, Mikulicz and systemic (MS) 20%, pancreato-hepato-biliary (PHB) 13%, retroperitoneal and aorta (RA) 26%. Sixteen per cent had an undefined phenotype. Seventy-seven per cent of the cases met the AECC. From the 24 patients not meeting the AECC, 33% met exclusion criteria, and 67% did not get a score ≥20 points. Incomplete pathology reports were associated to failure to meet the AECC. CONCLUSIONS: The PHB phenotype was rare among Spanish IgG4-RD patients. The MS phenotype was less frequent and the RA phenotype was more prevalent than in other, Asian patient series. An undefined phenotype should be considered as some patients do not fall into any of the categories. Three quarters of the cases met the 2019 AECC. Incomplete pathology reports were the leading causes of failure to meet the criteria.

Dacryoadenitis associated with IgG4-related disease in an Afro-Colombian adolescent. / Dacrioadenitis por enfermedad relacionada con IgG4 en una adolescente afrodescendiente de Colombia.

IgG4-related disease (IgG4-RD) is a recently recognized clinical condition with multiple aspects not yet elucidated. It is characterized by a fibrous inflammatory process that involves multiple organs and clinical, serological and histopathological findings, which represent a major challenge for the clinician. Classically described as an expansive tumor lesion with storiform fibrosis, lymphoplasmacytic infiltration (IgG4-positive) and elevated serum IgG4. Clinical features are variable, and pancreatic as well as extrapancreatic involvement has been reported, more frequently in Asian men over 50 years and rarely described in black people. We report the case of an Afro-Colombian teenage woman, who had a unilateral ocular protrusion of unknown cause, with histopathologic findings that revealed infiltration of lymphocyte and plasma cells into the lacrimal gland. It was positive for IgG4, ruling out other conditions, and confirming IgG4-related dacryoadenitis.