Need for consensus guidelines to standardise the assessment of germinal centres and other histopathological parameters in salivary gland tissue of patients with primary Sjögren's syndrome

We have read with great interest the letter to the editor by van Roon et al 1 commenting on our paper ‘Towards personalised treatment in primary Sjogren's syndrome: baseline parotid histopathology predicts responsiveness to rituximab treatment’.2 The authors argue that there is a need for standardisation of the histopathological characteristics of salivary gland tissue of patients with primary Sjogren's syndrome (pSS), in general, and of the presence of germinal centres (GCs), in particular. We fully agree with van Roon et al 1 and other authors about the need for consensus guidelines to standardise the histopathological evaluation of salivary gland biopsies in patients with pSS.3 A standardised scoring system may facilitate prognostication and stratification of patients with pSS and is needed for a valid evaluation of various clinical trials.3 In particular, histological definition of GCs in salivary gland tissue is warranted, since these structures can be difficult to detect in diagnostic H&E-stained tissue sections. Detection of GCs in the periductal lymphoid infiltrates of the salivary glands is clinically relevant, because the presence of these structures is associated with more severe disease.4 Importantly, the presence of GCs in minor salivary gland biopsies has been postulated to be a predictor of patients who are at risk of lymphoma development.5 …