CD8 Expression on Clonal B-CLL cells and CD8+ Lymphocytes in the Microenvironment, Relations with Prognosis and Survival

INTRODUCTION: In lymphoproliferative neoplasms including chronic lymphocytic leukemia (CLL), hairy cell leukemia and even multiple myeloma, the biology of the monoclonal cells as well as the surrounding cells which are called microenvironment of the bone marrow are known to be in an interplay.
METHODS: Data of 275 patients diagnosed with B-CLL were collected in a retrospective manner. Demographic features, laboratory including flow cytometry, immunoglobulins, genetic evaluations and clinical follow up were recorded from files.
RESULTS: 111 patients were female (40.4%) while 164 were male (59.6%). Mean age was 70.46 years (21-92). CD8 positivity on CLL cells was observed in 12 patients. No significance was observed regarding complications and survival. 71 patients demonstrated a dense surrounding CD8 positive lymphocytes. Of these patients, none had 17p deletion while 28 patients demonstrated 13q deletion (39.4% of CD8+ Treg group while 82.3% of all patients with 13q del) and 6 patients had 11q deletion. ITP, lowIgG levels, development of secondary malignancies, high percentage of bone marrow infiltration, Richter’s transformation were significantly corelated. CD8+ T lymphocyte richness in the microenvironment was significantly related with survival.
DISCUSSION AND CONCLUSION: Cancer is related with immunodefiency. With the evolution of tumors, they find ways to elude immune recognition. CD8 expression on B-CLL cells may not be explained with clinical features or prognosis. But The density of CD8 within the infiltrated bone marrow may explain the long term immune escape of CLL cells, with the effort to balance immune regulation by disease control, though resulting with increased autoimmunity.