α/β and γ/δ TCR+ lymphocyte infiltration in necrotising choroidal melanomas

Aim-To detect specific tumour infiltrating T cells (TIL) carrying antigen specific MHC-I restricted receptor genes on necrotising and non-necrotising malignant melanomas and to correlate the findings with clinical data. Methods-alpha/beta- and gamma/delta- TIL were determined by immunohistochemical staining in melanomas of patients with known follow up of more than 10 years. An antigen retrieval method was used to determine variable genes 61 and gamma 1 on TCR+ cells by an anti-TCR V delta 1 and anti-Cr gamma M1, and of V alpha and V beta TCR+ by an anti-pan-TCR+ alpha/beta antibody. Results-Intratumoral TIL were present in 86 of 113 (76.1%) necrotising melanomas (NMM) v 21 of 100 (21%) in non-necrotising melanomas (MM); of these, V alpha/beta- TCR+ cells were present in 52 of 74 (70.3%) TIL harbouring NMM v four of 21 (19%) MM; V gamma 1 in 29 of 74 (39.2%) NMM v two of 21 (10%) MM; and V delta 1 in 39 of 74 (52.7%) NMM v three of 21 (14%) MM. Extratumoral lymphocytic infiltration was seen in 86 (76.1%) NMM including V alpha/beta TCR+ cells in 10 (11.6%) cases, v five (5%) MM cases with no V alpha/beta TCR+ cells detected. V gamma 1 and V delta 1 TCR+ cells were not found in extratumoral infiltrates. Conclusions-In NMM, the median survival was 69.3 (range 6-237) months, 19 of 74 patients (25.7%) survived 5 years, and mortality was associated with advanced stage (p<0.001), patient age (p<0.023), and extent of necrosis (p<0.048). Survival was increased with evidence of V gamma 1 and V delta 1 TCR+ cells (p<0.026).