Number of CD4+ Cells and Location of Forkhead Box Protein P3–Positive Cells in Diagnostic Follicular Lymphoma Tissue Microarrays Correlates With Outcome

To examine the immune microenvironment in diagnostic follicular lymphoma (FL) biopsies and evaluate its prognostic significance. Immunohistochemistry was used to study numbers and location of cells staining positive for immune cell markers CD4, CD7, CD8, CD25, CD68, forkhead box protein P3 (FOXP3), T-cell intracellular antigen-1, and Granzyme B in tissue microarrays of paraffin-embedded, diagnostic lymph node biopsies taken from 59 FL patients who lived less than 5 years (short-survival group; n = 34) and more than 15 years (long-survival group; n = 25). CD4 and FOXP3 expression were significantly different between the two groups. Samples from the long-survival group were more likely than those from the short-survival group to have CD4+ staining cells and to have FOXP3-positive cells in a perifollicular location. This study has identified differences in immune cell composition of the diagnostic FL lymph node immune microenvironment and these have the potential for use as prognostic biomarkers in a routine histopathology setting.