Macrophage Polarization Reflects T Cell Composition of Tumor Microenvironment in Pediatric Classical Hodgkin Lymphoma and Has Impact on Survival

Abstract

Macrophages have been implicated in the pathogenesis of classical Hodgkin lymphoma (cHL) and have been suggested to have a negative impact on outcome. Most studies addressing the role of macrophages in cHL have relied on identification of macrophages by generic macrophage antigens, e.g., CD68. We have therefore conducted an in situ analysis of macrophage polarization in a series of 100 pediatric cHL (pcHL) cases using double staining immunohistochemistry, combining CD68 or CD163 with pSTAT1 (M1-like) or CMAF (M2-like). M1- or M2-polarised microenvironment was defined by an excess of one population over the other (>1.5). Expression of STAT1 and LYZ genes was also evaluated by RT-qPCR. Patients <14 years and EBV+ cases displayed higher numbers of CD68+pSTAT1+ cells than older children and EBV- cases, respectively (P=0.01 and P=0.02). A cytotoxic tumor microenvironment, defined by a CD8+/FOXP3+ ratio >1.5 was associated with higher numbers of CD68+pSTAT1+ (P=0.025) and CD163+pSTAT1+ macrophages (P<0.0005). Levels of STAT1 and LYZ expression were associated with the numbers of CD68+pSTAT1+ macrophages. EBV+ cHL cases disclosed a predominant M1 polarized microenvironment similar to Th1 mediated inflammatory disorders, while EBV- cHL showed a predominant M2 polarized microenvironment closer to Th2 mediated inflammatory diseases. Better overall-survival (OS) was observed in cases with higher numbers of CD163+pSTAT1+ macrophages (P=0.02) while larger numbers of CD163+CMAF+ macrophages were associated with worse progression-free survival (PFS) (P=0.02). Predominant M1-like polarization as disclosed by CD163+pSTAT1+/CD163+CMAF+ ratio > 1.5 was associated with better OS (P= 0.037). In conclusion, macrophage polarization in pcHL correlates with prevalent local T cell response and may be influenced by the EBV-status of neoplastic cells. Besides, M1-like and M2-like macrophages displayed differential effects on outcome in pcHL.

Role of tumor‐associated macrophages in human malignancies: friend or foe?

“…124 In a comparative analysis of CD68 and CD163, several studies indicated the superiority of CD163 compared with CD68 for predicting poor prognosis. 120,122,123 Barros et al 125 introduced a new immunohistochemical approach for identifying M1 and M2 macrophages in an analysis of pediatric Hodgkin lymphoma. By using double immunohistochemical staining combining CD68 or CD163 with pSTAT1 (M1-like) or CMAF (M2-like), 100 …”

Addressing the Symptoms or Fixing the Problem? Developing Countermeasures against Normal Tissue Radiation Injury

“…For example, the induction of capillary leakiness seen in the brain (175, 176), lung (177), skin (178), etc., which has been associated with upregulation of VEGF (176, 179) and hypoxia (180), is reminiscent of the increased vascular permeability (181, 182), aberrant pro-angiogenic signaling (183, 184) and areas of hypoxia (185, 186) characteristic of many tumors. Similarly, there is a growing understanding of the transition in macrophage state between M1 and M2 associated with the progression of radiation-associated late effects (118); alterations in the M1:M2 ratio are a common feature of the tumor microenvironment (187, 188) and are associated with immune tolerance (189, 190). Furthermore, chronic inflammation is now recognized as major factor in malignant disease (191).…”

Pathway‐focused gene expression profiles and immunohistochemistry detection identify contrasting association of caspase 3 (CASP3) expression with prognosis in pediatric classical Hodgkin lymphoma

“…Anti‐CD68 staining was performed to avoid the bias that could be introduced by counting macrophages with H‐RS‐like morphology and with phagocytosed apoptotic debris . CASP3‐positive H‐RS cells were counted using morphologic criteria by computer‐assisted microscopic analysis and were expressed as a percentage of all H‐RS cells. FFPE tonsil specimens were used as a positive control for detection of active CASP3.…”