Different operators and histologic techniques in the assessment of germinal center-like structures in primary Sjögren’s syndrome minor salivary glands

Abstract

ObjectiveA standardization of minor salivary gland (MSG) histopathology in primary Sjögren’s syndrome (pSS) has been recently proposed. Although there is strong agreement that germinal center (GC)-like structures should be routinely identified, due to their prognostic value, a consensus regarding the best protocol is still lacking. Aim of this study was to compare the performance of different histological techniques and operators to identify GC-like structures in pSS MSGs. MSG biopsies from 50 pSS patients were studied.MethodsThree blinded operators (one pathologist and two rheumatologists with different years of experience in pSS MSG assessment) assessed 50 MSGs of which one slide was stained with haematoxylin and eosin (H&E) and consecutive slides were processed to investigate CD3/CD20, CD21 and Bcl-6 expression.ResultsBy assessing 225 foci, the best agreement was between H&E-stained sections evaluated by the rheumatologist with more years of experience in pSS MSG assessment and CD3/CD20 segregation. In the foci with CD21 positivity, the agreement further increased. Bcl-6- foci could display a GC, detected with other staining, but not vice versa.ConclusionGC assessment on H&E-stained sections should be performed with caution, being operator-dependent. The combination of H&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.

Bcl6 for identification of germinal centres in salivary gland biopsies in primary Sjögren's syndrome

“…Detection of GCs in routine haematoxylin and eosin (H&E)‐stained sections can be challenging because small GCs may be overlooked and distinction between GCs and lymphoepithelial lesions may be difficult (Fisher et al, ; Haacke et al, ). Therefore, immunohistochemical identification using antibodies directed against CD21, expressed by FDCs (but also by B cells) or Bcl6, a transcription factor highly expressed by GC‐B cells, has been used (Bombardieri et al, ; Carubbi et al, ; Haacke et al, ), but consensus criteria regarding identification of GCs are lacking (Haacke et al, ). Hence, the aim of this study was to asses which staining is most suitable to unequivocally identify GCs in diagnostic salivary gland biopsies of pSS patients by comparing H&E, CD21 and Bcl6 stainings.…”

“…In a recent study, Carubbi et al analysed the usage of CD3/CD20 as well as CD21 and Bcl6 as markers for the detection of GCs (Carubbi et al, ). While they conclude that combination of CD3/CD20 and CD21 should be recommended for assessment of GCs, we clearly show here that usage of CD21 as surrogate marker for GCs significantly overestimates GC counts.…”

Sjögren syndrome: looking forward to the future

“…Regarding the histopathology of pSS, some conflicting data on the association between GC-like structures and lymphoma development can be explained by the lack of agreement on the methodology of assessment. 181 On the contrary, the association between higher FS and a higher risk of non-Hodgkin lymphoma was documented in several studies, and more recently, a FS ⩾4 was indicated as a risk factor for lymphoma development. 182 , 183 …”

Comparison of Rituximab Originator With CT-P10 Biosimilar in Patients With Primary Sjögren's Syndrome: A Retrospective Analysis in a Real-Life Setting

“…The evolution into B-cell lymphoma represents one of the main causes of decreased survival in pSS and occurs in about 5% of patients (4). B cells play a major role in the pathogenesis of pSS via antibody-dependent and -independent mechanisms, and their hyperactivity, along with salivary gland infiltration and development of B-cell follicles containing germinal center-like structures, represents the hallmarks of the disease (4)(5)(6)(7).…”

“…B cells play a major role in the pathogenesis of pSS via antibody-dependent and -independent mechanisms, and their hyperactivity, along with salivary gland infiltration and development of B-cell follicles containing germinal center–like structures, represents the hallmarks of the disease ( 4 – 7 ).…”