Saviana Gandolfo1, Michela Bulfoni2, Cinzia Fabro1, Sabino Russi3, Domenico Sansonno3, Carla Di Loreto2, Daniela Cesselli2, Salvatore De Vita4. 1. Rheumatology Clinic, Udine University Hospital, Department of Medical Area, University of Udine, Italy. 2. Institute of Anatomic Pathology, Udine University Hospital, Department of Medical Area, University of Udine, Italy. 3. Department of Biomedical Sciences and Human Oncology, University of Bari, Italy. 4. Rheumatology Clinic, Udine University Hospital, Department of Medical Area, University of Udine, Italy. salvatore.devita@asuiud.sanita.fvg.it.
Abstract
OBJECTIVES: To investigate the expression of thymic stromal lymphopoietin (TSLP) in primary Sjögren's syndrome (pSS), stratified according to the lymphoproliferative status, from a fully benign (fbSS) stage to myoepithelial sialadenitis (MESA) and to B-cell non-Hodgkin's lymphoma (NHL). METHODS: After initial serum studies in large numbers of pSS patients and in controls, TSLP was investigated also in pathologic salivary glands (SG) biopsies from 38 stratified pSS patients (13 fbSS; 13 MESA; 12 NHL) and from 13 controls with non-autoimmune sicca syndrome (nSS) by RT-PCR, immunohistochemistry and immunofluorescence. RESULTS: Significantly higher TSLP serum levels were shown in pSS than controls, increasing from fbSS to MESA and to NHL. In SG biopsies, TSLP-positive B lymphocytes increased with increasing lymphoproliferation, maximally in NHL, consistent with the detection of inducible TSLP long isoform (lfTSLP) mRNA only in MESA and NHL. By contrast, the constitutive TSLP short isoform (sfTSLP) mRNA showed no difference among subgroups. The TSLP expression by glandular epithelium declined with the progression from fbSS to MESA and to NHL. CONCLUSIONS: TSLP progressively increases from benign to malignant B-cell lymphoproliferation in pSS. The salivary epithelium expresses TSLP but, with the progression of lymphoproliferation, the B-cells may represent the major source of TSLP, in its long inducible isoform. A possible pathogenetic role of TSLP is herein hypothesised in pSS for the first time. Further analyses on TSLP, also as a biomarker of pSS and related lymphoproliferation, are worthwhile.
OBJECTIVES: To investigate the expression of thymic stromal lymphopoietin (TSLP) in primary Sjögren's syndrome (pSS), stratified according to the lymphoproliferative status, from a fully benign (fbSS) stage to myoepithelial sialadenitis (MESA) and to B-cell non-Hodgkin's lymphoma (NHL). METHODS: After initial serum studies in large numbers of pSSpatients and in controls, TSLP was investigated also in pathologic salivary glands (SG) biopsies from 38 stratified pSSpatients (13 fbSS; 13 MESA; 12 NHL) and from 13 controls with non-autoimmune sicca syndrome (nSS) by RT-PCR, immunohistochemistry and immunofluorescence. RESULTS: Significantly higher TSLP serum levels were shown in pSS than controls, increasing from fbSS to MESA and to NHL. In SG biopsies, TSLP-positive B lymphocytes increased with increasing lymphoproliferation, maximally in NHL, consistent with the detection of inducible TSLP long isoform (lfTSLP) mRNA only in MESA and NHL. By contrast, the constitutive TSLP short isoform (sfTSLP) mRNA showed no difference among subgroups. The TSLP expression by glandular epithelium declined with the progression from fbSS to MESA and to NHL. CONCLUSIONS:TSLP progressively increases from benign to malignant B-cell lymphoproliferation in pSS. The salivary epithelium expresses TSLP but, with the progression of lymphoproliferation, the B-cells may represent the major source of TSLP, in its long inducible isoform. A possible pathogenetic role of TSLP is herein hypothesised in pSS for the first time. Further analyses on TSLP, also as a biomarker of pSS and related lymphoproliferation, are worthwhile.