SAT0641 Performance and agreement of different operators and histological techniques for the assessment of germinal centres in minor salivary glands in primary sjÖgren's syndrome. (12th June 2018)

• Record Type: Journal Article
• Authors: Alunno, A.; Cipriani, P.; Coletti, G.; Bigerna, B.; Manetti, M.; Di Benedetto, P.; Bistoni, O.; Cipolloni, G.; Liakouli, V.; Ruscitti, P.; Gerli, R.; Giacomelli, R.; Carubbi, F.
• Is Part Of: Annals of the rheumatic diseases. Volume 77(2018)Supplement 2
• Page Start: 1171
• Page End: 1171
• Publication Date: 2018-06-12
• Subjects: Rheumatism -- Periodicals; 616.723005
• DOI: 10.1136/annrheumdis-2018-eular.3103
• Languages: English
• ISSNs: 0003-4967

Abstract

Abstract : Background: A standardisation of minor salivary gland (MSG) histopathology in primary Sjögren's syndrome (pSS) has been recently proposed by the EULAR study group on Sjögren's syndrome. Although there is strong agreement that germinal centres (GCs) should be routinely identified, due to their prognostic value, a consensus regarding the best protocol is still lacking. Objectives: Aim of this study was to compare the performance of different histological techniques and operators with variable experience in MSG histopathology to identify GCs in pSS MSGs. Methods: MSG biopsies from 50 pSS patients were studied. Three blinded operators (expert rheumatologist, expert pathologist and rheumatologist with scarce experience on MSG histopathology) scored one slide stained with haematoxilin and eosin (H and E). Consecutive slides were processed by immunofluorescence and immunohistochemistry to assess CD3/CD20, CD21 and Bcl-6 expression. Results: Overall, the prevalence of GC in MSG specimens (namely the presence of at least one focus positive for at least one operator or histological technique) ranged between 26% and 52%. By separate assessment of 225 foci, the best agreement was between H and E-stained sections evaluated by the expert rheumatologist and CD3/CD20 segregation (Cohen's kappa=0.72). In the foci with CD21 positivity, the agreement with the expert rheumatologist further increased (Cohen's kappa=0.75). Among the 3 methods employed, the best agreement was observed between B/T-cell segregation and the positivity for CD21 staining (0.84). The absence of Bcl-6 in a focus does not necessarily rule out the presence of the GC detected with other stainings, Conclusions: GC assessment on H and E-stained sections should be performed with caution, as it is dependent on the background and expertise of the operator. The combination of H and E with CD3/CD20 and CD21 staining should be recommended as it is reliable, feasible, able to overcome the bias of operator experience and easily transferrable into routine practice. Disclosure of Interest: None declared