Significance of leukocyte-specific transcript 1 levels in nasal mucosal tissue to predict recurrence of nasal polyps

Abstract Objective: Chronic Rhinosinusitis with Polyps (CRSwNP) is characterized by high heterogeneity and postoperative recurrence rate. This study aims to explore the clinical significance of tissue Leukocyte-Specific Transcript 1 (LST1) in predicting CRSwNP recurrence. Methods: We enrolled 62 CRSwNP patients including 30 primary CRSwNP and 32 recurrent CRSwNP patients, and 40 Healthy Controls (HC). Tissue samples were collected. Tissue LST1 expression was assessed by Reverse Transcription-Polymerase Chain Reaction (RT-PCR), Western Blotting (WB) and Immunofluorescence (IF) staining. The predictive values of LST1 expression for CRSwNP postoperative recurrence were assessed through the Receiver Operating Characteristic (ROC) curves. Results: The tissue levels of LST1 were significantly increased in the CRSwNP group than the HC group, especially in the recurrent group, and the elevated LST1 mRNA levels were positively correlated with the peripheral eosinophil percentages, tissue eosinophil counts and percentages. IF staining results showed that the LST1 protein levels were higher in CRSwNP patients, especially in the recurrent patients than in the HC group. ROC curves highlighted that tissue LST1 levels were associated with recurrent CRSwNP and exhibited a higher predictive ability for postoperative CRSwNP recurrence. Conclusion: This was the first report suggesting that LST1 expression was upregulated and associated with mucosal eosinophil infiltration and CRSwNP recurrence. Tissue LST1 could be a promising biomarker for predicting postoperative recurrence in CRwNP patients.

Identification of Leukocyte-Specific Protein 1-Positive Cells: A Clue to the Cell of Origin and a Marker for the Diagnosis of Dermatofibroma

BACKGROUND: Dermatofibroma (DF) comprises a heterogeneous group of mesenchymal tumors, with fibroblastic and histiocytic elements present in varying proportions. The cell of origin of DF has been investigated, but remains unclear. OBJECTIVE: The present study attempted to investigate the expression of leukocyte-specific protein 1 (LSP1), a marker of fibrocytes, in DF. Additionally, we evaluated the effectiveness of LSP1 in the differential diagnosis of DF from dermatofibrosarcoma protuberans (DFSP). METHODS: Immunohistochemical staining was performed on 20 cases of DF using antibodies against LSP1, CD68, and factor XIIIa (FXIIIa). In addition, the expression of LSP1 and FXIIIa was evaluated in 20 cases of DFSP. RESULTS: Eighteen of 20 cases (90%) of DF stained positive for LSP1, with variation in the intensity of expression. CD68 was positive in 10 cases (50%), and FXIIIa was expressed in all cases of DF. There were differences between the regional expression patterns of the three markers in individual tumors. In contrast, only 2 of 20 cases of DFSP expressed LSP1, and none of DFSP cases stained positive for FXIIIa. CONCLUSION: The LSP1-positive cells in DF could potentially be fibrocyte-like cells. FXIIIa and CD68 expression suggests that dermal dendritic cells and histiocytes are constituent cells of DF. It is known that fibrocytes, dermal dendritic cells and histiocytes are all derived from CD14+ monocytes. Therefore, we suggest that DF may originate from CD14+ monocytes. Additionally, the LSP1 immunohistochemical stain could be useful in distinguishing between DF and DFSP.