Automated spatial analysis reveals proximity of human leukocyte antigen class I-positive tumor cells and CD8-positive cells of the tumor microenvironment in stage I seminoma.

BACKGROUND

The testis is an immune-privileged organ due to its lack of functional human leukocyte antigen (HLA) class I expression. However, the expression status of HLA class I in testicular seminoma, which is characterized histologically by lymphocytic infiltration, remains unclear.

MATERIALS AND

METHODS

We performed immunohistochemistry to evaluate HLA class I expression and its spatial relationship with CD8-positive cells in 20 cases of stage I seminoma. Each specimen was scored manually and further analyzed using the HALO image analysis platform.

RESULTS

Manual scoring and HALO analysis showed 80 % concordance. HLA class I expression was positive in 13 cases (65 %). Tumors were classified into three categories based on the expression levels. The number of infiltrating CD8-positive cells was significantly correlated with HLA class I expression. Spatial analysis revealed that tumors with higher HLA class I expression had shorter distances between HLA class I-positive tumor cells and CD8-positive cells.

CONCLUSION

Seminoma cells expressing HLA class I tended to be located in close proximity to CD8-positive T cells, suggesting a spatial relationship that might influence the tumor immune microenvironment.