IMMUNOHISTOCHEMICAL ANALYSIS OF INFLAMMATORY RESPONSE IN MINOR SALIVARY GLAND BIOPSY AMONG PEDIATRIC PATIENTS WITH SJOGREN SYNDROME

Abstract

<h3>Introduction</h3> Sjogren syndrome (SS) is a chronic autoimmune rheumatic disease characterized by lymphocytic infiltration of exocrine glands and other organs. The spectrum of clinical manifestations suggests that SS clinical phenotype in children is more heterogeneous than that in adults. The objective of this study was to perform histopathological and immunohistochemical analysis on labial minor salivary gland (LMSG) biopsy in pediatric SS (PSS). <h3>Methods</h3> An IRB approved retrospective chart review encompassing years from 2018-2020, of the University of Florida Oral Pathology Biopsy Service and the Center for Orphaned Autoimmune Disorders, was performed. The inclusion criteria encompassed patients with LMSG biopsy suggestive of SS (positive focus score ≥ 4), and age under 18. Demographics, clinical data, laboratory test results, and microscopic diagnoses/slides were reviewed. Immunohistochemical staining with antibodies specific for CD4, CD8, CD20, CD27, FOXP3, and IL-17 were performed. Staining intensity/positivity was calculated with Aperio ImageScope, positive pixel count software. <h3>Results</h3> Ten cases were included. The mean age was 14.3 years old (range 9-18) with 1:1 female to male ratio. Five patients reported dry mouth, and six reported dry eyes. Of ten patients, 70% of the patients were positive for anti-SSA, and 50% were positive for anti-SSB. Positive ANA was seen in nine patients. All biopsies demonstrated positive focal lymphocytic sialadenitis ranging from 6 to 17 foci per 4 mm². A predominance of CD4+T cells over CD8+T cells and CD20+B cells were noted in all biopsies. FoxP3+ regulatory T cells showed minimal inflammatory cell positivity with mean of 0.2%. The memory CD27+ B cells were almost equally expressed as CD4 with mean of 16.2% and 14.1% respectively.IL-17 positivity was diffuse in the stromal/glandular staining, which prevented a proper assessment with the pixel algorithm. <h3>Conclusions</h3> LMSG infiltrates in PSS consist predominately of helper-T cells and memory-B cells with few suppressive regulatory-T cells.