Performance of the 2019 American College of Rheumatology/European League Against Rheumatism Classification Criteria for IgG4-Related Disease in a Latin American Cohort.

BACKGROUND/OBJECTIVE: The 2019 American College of Rheumatology/European League Against Rheumatism Classification Criteria (2019 AECC) for IgG4-related disease (IgG4-RD) is considered a significant advancement in the study of this condition. Most studies evaluating their performance have focused on White and Asian patients, leaving a knowledge gap regarding Latin American populations. Therefore, this study aimed to assess the performance of the 2019 AECC for IgG4-RD in a cohort of Latin American patients. METHODS: A multicenter medical records review study was conducted, involving centers from Argentina, Chile, Mexico, Peru, and Uruguay. Data on IgG4-RD patients and mimicker conditions were collected through a standardized online form. The criterion standard for diagnosing IgG4-RD was based on the fulfillment of the Comprehensive Diagnostic Criteria for IgG4-RD and/or the Consensus Statement on Pathology. The 2019 AECC was retrospectively applied. RESULTS: We included 300 patients, with 180 (60%) having IgG4-RD and 120 (40%) having mimicker conditions. The 2019 AECC had a sensitivity of 66.7% and a specificity of 100%. Sensitivity increased to 73.3% when disease-specific autoantibody items were removed, without affecting specificity. The true-positive cases had more involved organs, a higher availability of biopsy results, and were more likely to belong to the Mikulicz/systemic and proliferative phenotypes. CONCLUSIONS: The use of the 2019 AECC for IgG4-RD in a Latin American population confirms its high specificity in excluding those without the disease. The presence of concomitant autoimmune diseases and clinically nonsignificant disease-specific autoantibodies excludes a significant number of patients from fulfilling the criteria.

ANCA-associated vasculitis and IgG4-related disease overlap syndrome: a case report and literature review.

Anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitides are infrequent autoimmune diseases characterized by inflammation of the walls of small vessels leading to tissue and endothelial damage. On the other hand, IgG4-related disease is a fibroinflammatory disease characterized histologically by lymphoplasmacytic infiltrates with IgG4+ plasma cells, storiform fibrosis, and obliterative phlebitis that may affect nearly every organ of the body. There are similarities in clinical, serological, radiological, and histopathological features between both diseases, and hence, they usually mimic each other complicating the differential diagnosis. Furthermore, reports of patients with the coexistence of both conditions (overlap syndrome) have been reported. We herein report a patient with an unequivocal diagnosis of ANCA-associated vasculitis, specifically granulomatosis with polyangiitis (posterior uveitis, polyneuropathy, pauci-immune glomerulonephritis with crescent formation and granulomas, and MPO-ANCA positivity) and IgG4-related disease (thoracic aortitis, tubulointerstitial nephritis with prominent IgG4+ plasma cell infiltration, fibrosis, and obliterative arteritis, high levels of serum IgG4, and eosinophilia) overlap syndrome.

Coexistance of Amyloidosis and Primary Sjögren's Syndrome: An Overview.

BACKGROUND: The association of primary Sjogren´s Syndrome (SS) and amyloidosis has been recognized but scarcely assessed. OBJECTIVE: Herein we analyzed the literature regarding this association in order to describe a SS phenotype prone to both conditions. METHODS: PubMed and CINAHL databases were searched from inception until April 2016 for the keywords: Amyloidosis, amyloid, Sjögren's syndrome and their combinations. RESULTS: Most of the cases corresponded to localized amyloidosis mainly at skin and lung, whereas only three cases were systemic. Other places of localized amyloidosis were the kidney, tracheobronchial, tongue, breast, salivary gland and vocal cord. Most of the localized forms corresponded to AL type, whereas AA amyloidosis was uncommon. The diagnosis of amyloidosis followed the SS onset (1-25 years) and in the majority of patients the presence of B cell hyperactivity traduced by hypergammaglobulinemia, positive rheumatoid factor and/or anti-Ro/SSA and anti-La/SSB antibodies were observed. In seven patients, an associated lymphoma was also documented. CONCLUSION: The spectrum of lymphoid proliferation associated with SS extends beyond the classical B cell lymphoma. Localized or systemic amyloidosis might coexist with primary SS. Localized amyloidosis should be suspected in patients with consistently high serologic activity and suggestive lesions.