Contributions
Abstract: PB2337
Type: Publication Only
Background
Diffuse Large B-cell Lymphoma (DLBCL) is the most common form of Non-Hodgkin lymphoma characterized by clinical and biological heterogeneity attributable both to the tumor cells and the complex tumor-microenvironment surrounding them. Tumor-associated macrophages (TAMs) and mast cells are two major components of the tumor inflammatory infiltrate with a definite role in enhancing tumor angiogenesis.
Aims
In this study, we have investigated CD68 and tryptase expression and their relationship with microvascular density (MVD) in chemo-resistant and chemo-sensitive patients affected by DLBCL.
Methods
This retrospective study reviewed data from 29 patients diagnosed with DLBCL. Paraffin-embedded tissues representatives of the DLBCL cases were sectioned and the slides were then incubated with antibodies against CD68, tryptase and CD31. For each case, three slides stained for CD68, tryptase and CD31 expression were scanned using the whole-slide scanning platform Aperio Scanscope CS. CD68 and tryptase expression were assessed with the Positive Pixel Count algorithm embedded in the Aperio ImageScope software and reported as a percentage of positivity, defined as the number of positively stained pixels on the total of pixels of the image. Fields were selected in areas with the most intensive CD68 and tryptase expression.To quantify MVD, the microvessel analysis algorithm embedded in the Aperio ImageScope software was used. Fields were selected in the areas of highest vascularization and only vessels with defined shape and lumen were considered. Statistical significance of CD68, tryptase and CD31 expression between responders and non-responders groups was assessed with the unpaired t-test. Correlation analysis between CD68 and MVD and tryptase and MVD was performed with the Spearman non parametric correlation test.
Results
CD68 and tryptase expression as well as MVD were increased in chemo-resistant patients when compared with chemo-sensitive patients. Tryptase expression showed a positive correlation with MVD, supporting a role for mast cell in DLBCL tumor angiogenesis, while CD68 correlation with MVD was not significant, indicating a different role for TAMs than angiogenesis in DLBCL.
Conclusion
Overall, this study is one of the first to compare the expression levels of CD68 and tryptase to MVD in DLBCL. Our results show that although CD68 expression is increased in non-responder DLBCL cases, this increased expression is not correlated with the increase in MVD, while tryptase increased expression in non-responders group appear to be correlated significantly with MVD, strengthening the association between mast cells and tumor angiogenesis.
Session topic: 19. Non-Hodgkin lymphoma Biology & Translational Research
Keyword(s): Angiogenesis, Macrophage, Mast cell, Non-Hodgkin's lymphoma
Abstract: PB2337
Type: Publication Only
Background
Diffuse Large B-cell Lymphoma (DLBCL) is the most common form of Non-Hodgkin lymphoma characterized by clinical and biological heterogeneity attributable both to the tumor cells and the complex tumor-microenvironment surrounding them. Tumor-associated macrophages (TAMs) and mast cells are two major components of the tumor inflammatory infiltrate with a definite role in enhancing tumor angiogenesis.
Aims
In this study, we have investigated CD68 and tryptase expression and their relationship with microvascular density (MVD) in chemo-resistant and chemo-sensitive patients affected by DLBCL.
Methods
This retrospective study reviewed data from 29 patients diagnosed with DLBCL. Paraffin-embedded tissues representatives of the DLBCL cases were sectioned and the slides were then incubated with antibodies against CD68, tryptase and CD31. For each case, three slides stained for CD68, tryptase and CD31 expression were scanned using the whole-slide scanning platform Aperio Scanscope CS. CD68 and tryptase expression were assessed with the Positive Pixel Count algorithm embedded in the Aperio ImageScope software and reported as a percentage of positivity, defined as the number of positively stained pixels on the total of pixels of the image. Fields were selected in areas with the most intensive CD68 and tryptase expression.To quantify MVD, the microvessel analysis algorithm embedded in the Aperio ImageScope software was used. Fields were selected in the areas of highest vascularization and only vessels with defined shape and lumen were considered. Statistical significance of CD68, tryptase and CD31 expression between responders and non-responders groups was assessed with the unpaired t-test. Correlation analysis between CD68 and MVD and tryptase and MVD was performed with the Spearman non parametric correlation test.
Results
CD68 and tryptase expression as well as MVD were increased in chemo-resistant patients when compared with chemo-sensitive patients. Tryptase expression showed a positive correlation with MVD, supporting a role for mast cell in DLBCL tumor angiogenesis, while CD68 correlation with MVD was not significant, indicating a different role for TAMs than angiogenesis in DLBCL.
Conclusion
Overall, this study is one of the first to compare the expression levels of CD68 and tryptase to MVD in DLBCL. Our results show that although CD68 expression is increased in non-responder DLBCL cases, this increased expression is not correlated with the increase in MVD, while tryptase increased expression in non-responders group appear to be correlated significantly with MVD, strengthening the association between mast cells and tumor angiogenesis.
Session topic: 19. Non-Hodgkin lymphoma Biology & Translational Research
Keyword(s): Angiogenesis, Macrophage, Mast cell, Non-Hodgkin's lymphoma