A novel scoring system for TIGIT expression in classic Hodgkin lymphoma.

Clinical use of immune-checkpoints inhibitors (anti PD-1/PD-L1) resulted very effective for the treatment of relapsed/refractory classic Hodgkin Lymphoma (CHL). Recently, T cell Ig and ITIM domains (TIGIT) has been recognized as an immune checkpoint receptor able to negatively regulate T cell functions. Herein, we investigated the expression of TIGIT in CHL microenvironment in order to find a potential new target for inhibitor therapy. TIGIT, PD-1 and PD-L1 expression was evaluated in 34 consecutive patients with CHL. TIGIT expression in T lymphocytes surrounding Hodgkin Reed-Sternberg (HRS) cells was observed in 19/34 patients (56%), of which 11 (58%) had advanced stages. In 16/19 (84%) cases, TIGIT+ peritumoral T lymphocytes showed also PD-1 expression. All 15 TIGIT- patients had PD-L1 expression in HRS cells (100%) while among 19 TIGIT+ patients, 11 (58%) were PD-L1+ and 8 (42%) were PD-L1-. Using a new scoring system for TIGIT immunoreactivity, all TIGIT+ cases with higher score (4/19) were PD-L1-. Our results confirm co-expression of TIGIT and PD-1 in peritumoral T lymphocytes. Of relevance, we demonstrated a mutually exclusive expression of TIGIT and PD-L1 using new TIGIT scoring system able to identify this immunocheckpoints' modulation. These results pave the way to new therapeutic strategies for relapsed/refractory CHL.

Primary bone lymphoma of the talus: a challenging diagnosis.

PURPOSE: Diagnostic challenges are common in clinical practice and diagnostic or classification criteria for musculoskeletal conditions cannot overshadow clinical skills. METHODS: We present the case of a young man who complained of prolonged articular pain and mild swelling of the right ankle in the absence of other remarkable data. Apparently fulfilling the Budapest diagnostic criteria for complex regional pain syndrome, the patient was treated accordingly, but the pain increased over time. Then the patient underwent an additional diagnostic workup including synovial and bone biopsies in 2 separate occasions with the second one demonstrating diffuse lymphoid infiltrate compatible with lymphoma. RESULTS: The conclusive diagnosis of primary diffuse large B-cell lymphoma of the talus was made and adequate treatment initiated. CONCLUSIONS: The diagnostic difficulties as well as the importance of a multidisciplinary approach for complex cases are highlighted in this report.