Do high numbers of salivary gland-infiltrating B cells predict better or worse outcomes after rituximab in patients with primary Sjögren's syndrome?

Abstract

International audienc

The value of rituximab treatment in primary Sjögren's syndrome

“…Explanations for the apparent discrepancy between the study of Cornec et al and our study have been extensively discussed elsewhere [60,61]. Our findings that high absolute numbers and proportions of B cells in the parotid gland are associated with ESSDAI response suggest that the number of B cells in the target tissue influences systemic disease activity.…”

In primary Sjögren's syndrome high absolute numbers and proportions of B cells in parotid glands predict responsiveness to rituximab as defined by ESSDAI, but not by SSRI

“…In essence, we showed in our paper that absolute numbers of CD20+ cells/mm 2 of parenchyma of parotid gland tissue are predictive for the responsiveness of patients with pSS to rituximab (RTX) treatment. Cornec et al argue that there is a discrepancy in outcomes presented in their study and our study,1 as they observed that a high proportion of minor salivary gland B cells predict the absence of a clinical response to RTX 3. As we will show and explain here, there is no inconsistency between the two studies and most of the apparent discrepancy is likely the result of differences in how the tissues are analysed and how the disease activity is established.…”

“…With great interest we have read the letter to the editor by Cornec et al 1 regarding our paper ‘Towards personalised treatment in primary Sjögren's syndrome (pSS): baseline parotid histopathology predicts responsiveness to rituximab treatment’ 2. In essence, we showed in our paper that absolute numbers of CD20+ cells/mm 2 of parenchyma of parotid gland tissue are predictive for the responsiveness of patients with pSS to rituximab (RTX) treatment.…”

“…We measured absolute numbers of CD20+ B cells/mm 2 of parenchyma, while Cornec et al assessed the proportion of B cells 1 3. Obviously, even when there is a change in absolute numbers of B cells in the tissue, the B/T cell ratio still can remain the same.…”

“…Since parotid gland biopsies include areas of fat and fibrous tissue and intraparenchymal lymph nodes, we excluded these areas manually from the analysis, in order to increase the accuracy of the data. We would like to emphasise that, as stated in the section on ‘Immunohistochemical analysis’ in the materials and methods of our article,2 the whole slide (except from fat and fibrous tissue) was evaluated and areas of interest were not electively chosen, as implied by Cornec et al 1. The methodology used by Cornec et al is based on digital pixel counting procedure developed by Costa et al 1 3 5.…”