[530] Differential Expression of CCL5/RANTES in Alpha Beta vs. Gamma Delta Subtypes of Subcutaneous Panniculitis-Like T-Cell Lymphoma (SPTCL).

Xuan Wang, Paul Chadwick, Cynthia M Magro. New York Presbyterian Hospital-Weill Cornell Medical Center, NY

Background: SPTCL has 2 distinct subtypes, alpha beta (αβ) and gamma delta (γδ). The former is generally composed of CD4-CD8+CD56-βF1+ cells with a favorable prognosis and uncommon association with hemophagocytic syndrome (HPS), while the latter is of CD4-CD8-CD56+/-βF1- T-cell phenotype with a poor outcome and frequent manifestation of HPS. The mechanism underlying the prognostic differences is unknown. Recent studies have shown that increased expression of Th1 chemokine, CCL5/RANTES is associated with pathogenesis and disease progression in obesity and atherosclerosis, via recruitment and activation of macrophages and T cells. Whether CCL5 plays a role in SPTCL is unclear.
Design: Skin biopsies were studied from 4 γδ and 3 αβ SPTCLs. IHC results of CCL5, selected T-cell markers and cytotoxic proteins were compared between the two forms of SPTCL.
Results: IHC results are shown below for γδ and αβ forms of SPTCL.

Table 1
Subtype of SPTCL% of CCL5-Postive CellsCD56granzyme BTIA-1CD5CD7CD4/CD8
γδ>90+++-+-/-
γδ>80+++---/-
γδ∼30-++++-/-
γδ>90+++-+-/-
αβ<25NA+NA++⇓/+
αβ<5-NA+++-/+
αβ<5-+++++/+




Three of 4 γδ SPTCLs demonstrated diffuse and strong staining pattern of CCL5. All 3 cases of αβ SPTCLs had significantly lower number of CCL5-positive cells with much decreased staining intensity. In 1 γδ SPTCL, ∼30% of lymphoma cells were positive for CCL5. Interestingly, the lymphoma cells were CD56-, while those of the other γδ SPTCLs were positive.
Conclusions: Chemokine CCL5/RANTES is diffusely expressed in malignant cells of γδ SPTCL but not in αβ SPTCL. Strong CCL5 expression is seen in lymphoma cells rimming adipocytes in γδ SPTCL. This expression pattern raises the possibility that CCL5 might play a role in adipotropism of SPTCL, similarly to its proposed role in adipose tissue inflammation associated with obesity. Specifically the ligand for CCL5, CCR5, is expressed by adipocytes. Further, the CCL5-CCR5 lymphocyte-adipocyte interaction may be associated with activation of macrophages, leading to hemophagocytosis and increased apoptosis, and thus the more aggressive clinical course seen in γδ SPTCL.
Category: Dermatopathology

Wednesday, March 2, 2011 1:00 PM

Poster Session VI # 110, Wednesday Afternoon

 

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