ABSTRACT
Limited information is available regarding the incidence and features of lymphocyte expansions after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Large granular lymphocytes (LGL) expansions have been reported after bone marrow or peripheral blood, but not after unrelated cord blood (UCB) allo-HSCT, associated with indolent clinical courses and favorable outcomes. Here, we considered 85 recipients of UCB allo-HSCT to more broadly define the impact of lymphocytosis, not limited to LGL. Sustained lymphocytosis was observed in 21 (25%) patients at a median onset of 12.6 months and with a median duration of 12 months. Immunophenotypic analysis showed predominantly CD8+ T and/or polyclonal B-cell expansions. Three patients only had monoclonal T-cell expansion. CMV reactivation was significantly more frequent in the group of patients with lymphocytosis (76% vs 28%, P=0.0001), but was not associated with survival. Conversely, 2-year disease-free survival and overall survival were significantly higher for lymphocytosis patients (85% vs 55%, P=0.01 and 85% vs 63%, P=0.03, respectively). In conclusion, expansion of T or B lymphocytes after UCB allo-HSCT in adults is not a rare event. Although occurring relatively late after transplant, this feature is predictive of a better outcome for the patients.
Subject(s)
B-Lymphocytes/metabolism , CD8-Positive T-Lymphocytes/metabolism , Cord Blood Stem Cell Transplantation , Hematologic Neoplasms/blood , Hematologic Neoplasms/therapy , Hematopoietic Stem Cell Transplantation , Adult , Aged , Allografts , B-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/immunology , Disease-Free Survival , Follow-Up Studies , Hematologic Neoplasms/mortality , Humans , Male , Middle Aged , Survival RateABSTRACT
Multiparameter flow cytometry (MFC) has become an integral part of the diagnosis and classification of hematological malignancies. However, several nonmalignant or premalignant disorders may benefit from this technology in hematology laboratories. This review provides information on the normal immunophenotypic characteristics of peripheral blood leukocyte subsets and their modifications in several clinical conditions. The usefulness of MFC and the specific markers that can be investigated in hyperlymphocytosis, infection, hypereosinophilia, paroxysmal nocturnal hemoglobinuria, and large granular lymphocyte disorders is described. Mention is also made of the developments of MFC for analyses of red blood cells or platelets.
Subject(s)
Flow Cytometry , Hematologic Diseases/blood , Hematologic Diseases/diagnosis , Biomarkers , Blood Cell Count/methods , Blood Platelets/metabolism , Erythrocytes/metabolism , Flow Cytometry/methods , Hematologic Neoplasms/blood , Hematologic Neoplasms/diagnosis , Humans , Immunophenotyping/methods , Leukocytes/metabolism , PhenotypeABSTRACT
Analysis of the T-cell receptor (TCR) repertoire by flow cytometry proved to be relevant for investigating T-cell diversity and detecting reactive cells in blood samples. We used this approach to characterize non-malignant T-lymphocytes in lymph nodes and give insights into their origin. The TCR repertoire of CD4+ and CD8+ T-cells from 81 lymph nodes was analyzed with a four-color flow cytometer using a wide panel of 25 anti-Vbeta monoclonal antibodies. Flow cytometry proved to be a useful and informative technique. We demonstrated a diversified TCR-Vbeta repertoire, and only low level expansions, in 53% of the samples. They involved nearly all Vbeta families, were more frequent in the CD8+ subset of older patients, but were not related to pathology. No evidence could be demonstrated in favor of stimulation by common antigens. Interestingly, the TCR-Vbeta repertoire proved to be very similar in lymph nodes and blood samples. Our results argue that in the cases studied, lymph node enlargement is mainly due to an increased homing of circulating T-cells. They also provide reference values for expression of 25 TCR-Vbeta in lymph nodes, which could serve as a basis for further applications in diagnosis of T-cell lymphoproliferative disorders.