Bone Marrow Lymphocyte Subsets Research Articles

Long-Term Human Immune Reconstitution, T-Cell Development, and Immune Reactivity in Mice Lacking the Murine Major Histocompatibility Complex: Validation with Cellular and Gene Expression Profiles.

Humanized mice transplanted with CD34+ hematopoietic cells (HPCs) are broadly used to study human immune responses and infections in vivo and for testing therapies pre-clinically. However, until now, it was not clear whether interactions between the mouse major histocompatibility complexes (MHCs) and/or the human leukocyte antigens (HLAs) were necessary for human T-cell development and immune reactivity. We evaluated the long-term (20-week) human hematopoiesis and human T-cell development in NOD Scid Gamma (NSG) mice lacking the expression of MHC class I and II (NSG-DKO). Triplicate experiments were performed with HPCs obtained from three donors, and humanization was confirmed in the reference strain NOD Rag Gamma (NRG). Further, we tested whether humanized NSG-DKO mice would respond to a lentiviral vector (LV) systemic delivery of HLA-A*02:01, HLA-DRB1*04:01, human GM-CSF/IFN-α, and the human cytomegalovirus gB antigen. Human immune reconstitution was detectable in peripheral blood from 8 to 20 weeks after the transplantation of NSG-DKO. Human single positive CD4+ and CD8+ T-cells were detectable in lymphatic tissues (thymus, bone marrow, and spleen). LV delivery harnessed the detection of lymphocyte subsets in bone marrow (αβ and γδ T-cells and NK cells) and the expression of HLA-DR. Furthermore, RNA sequencing showed that LV delivery increased the expression of different human reactome pathways, such as defense responses to other organisms and viruses. Human T-cell development and reactivity are independent of the expression of murine MHCs in humanized mice. Therefore, humanized NSG-DKO is a promising new model for studying human immune responses, as it abrogates the xenograft mouse MHC interference.

Early changes of bone metabolites and lymphocyte subsets may participate in osteoporosis onset: a preliminary study of a postmenopausal osteoporosis mouse model.

Metabolic and immune changes in the early stages of osteoporosis are not well understood. This study aimed to explore the changes in bone metabolites and bone marrow lymphocyte subsets and their relationship during the osteoporosis onset. We established OVX and Sham mouse models. After 5, 15, and 40 days, five mice in each group were sacrificed. Humeri were analyzed by microCT. The bone marrow cells of the left femur and tibia were collected for flow cytometry analysis. The right femur and tibia were analyzed by LC-MS/MS for metabolomics analysis. Bone microarchitecture was significantly deteriorated 15 days after OVX surgery. Analysis of bone metabolomics showed that obvious metabolite changes had happened since 5 days after surgery. Lipid metabolism was significant at the early stage of the osteoporosis. The proportion of immature B cells was increased, whereas the proportion of mature B cells was decreased in the OVX group. Metabolites were significantly correlated with the proportion of lymphocyte subsets at the early stage of the osteoporosis. Lipid metabolism was significant at the early stage of the osteoporosis. Bone metabolites may influence bone formation by interfering with bone marrow lymphocyte subsets.

Immune profiles to predict bortezomib-based treatment response for multiple myeloma patients

BackgroundTo evaluate the distribution of bone marrow immune cell subsets and their correlation with treatment efficacy in patients with multiple myeloma (MM). MethodsWe analyzed the bone marrow lymphocyte subsets of 186 newly diagnosed MM patients at diagnosis and their correlation with clinical characteristics. In our study, eight-color flow cytometry, a method commonly used to detect plasma cell phenotypes, was used to analyze seven bone marrow immune cell groups by change gate-strategy. ResultsFirst, for all the 7 immune cell groups, the percentage of immature B cells was significantly lower in stage III patients than in stage I patients, while the trend was reversed in memory B cells in both the International Staging System(p = 0.004) and Revised International Staging System(p = 0.018). Second, the percentage of naïve B cells were significantly lower in patients with severe anemia, while the percentage of memory B cells had reversed trend. The percentage of immature B cells were lower in patients with Cr ≥ 2 mg/dL than in patients with Cr < 2 mg/dL. Then we followed the treatment efficacy of 152 patients who received four cycles of induction therapy (bortezomib + dexamethasone or bortezomib + lenalidomide + dexamethasone) and analyzed the relationship between bone marrow lymphocyte subsets at the initial stage and treatment response datasets. We found that both the percentage of B cells(p＜0.001) and immature B(p = 0.002) were increased in patients who achieved very good partial remission(VGPR) after four cycles of induction therapy. The ROC results indicated the combination of the multiple immune subgroups had predictive values (AUC = 0.802, p<0.001) in the treatment effect after four cycles of induction therapy. ConclusionsOverall, these results suggest that the analysis of lymphocyte subsets along with plasma cell immunophenotyping could be a potential index for determining the prognosis of MM patients.

Prognostic significance of the frequencies of bone marrow lymphocyte subsets in adult acute myeloid leukemia at diagnosis.

Immune microenvironment plays an important role in the occurrence and development of acute myeloid leukemia (AML). Studies assessing the prognostic significance of bone marrow (BM) lymphocyte subsets' frequencies at diagnosis in patients with AML were limited. Fresh BM samples collected from 97 adult AML patients at diagnosis were tested for lymphocyte, T, CD4+ T, CD8+ T, γδT, NK, and B cell frequencies using multi-parameter flow cytometry. Low frequencies of lymphocytes, T, CD4+ T, and CD8+ T cells were associated with significantly lower rates of one-course complete remission (CR) (all p < 0.05). Moreover, the frequency of CD4+ T cells independently predicted one-course CR achievement (p = 0.021). Low frequencies of T and CD8+ T cells were significantly associated with lower relapse-free survival (RFS) rates (p = 0.032; 0.034), respectively, and a low frequency of CD8+ T cells was associated with a significantly lower overall survival (OS) rate (p = 0.028). Combination of frequency of CD8+ T cells and ELN risk stratification showed that patients with ELN-intermediate/adverse risk + high CD8+ T cell frequency had a similar RFS rate to those with ELN-favorable risk + high CD8+ T cell frequency and those with ELN-favorable risk + low CD8+ T cell frequency (p = 0.88; 0.76), respectively. The RFS rate of patients with ELN intermediate/adverse risk + low CD8+ T cell frequency was significantly lower than that of all aforementioned patients (p = 0.021; 0.0007; 0.028), respectively. The frequencies of BM lymphocyte subsets at diagnosis predicted clinical outcomes and could help improve risk stratification in AML.

The Distribution and Significance of Activated T Cells and Lymphocyte Subsets in Myelodysplastic Syndrome

To investigate the distribution of bone marrow lymphocyte subsets in patients with myelodysplastic syndrome(MDS),the proportion of activated T cells with immunophenotype CD3+HLA-DR+ in the lymphocytes and its clinical significance, and to understand the effects of different types of MDS, different immunophenotypes, and different expression levels of WT1 on the proportion of lymphocyte subsets and activated T cells. The immunophenotypes of 96 MDS patients, the subsets of bone marrow lymphocytes and activated T cells were detected by flow cytometry. The relative expression of WT1 was detected by real-time fluorescent quantitative PCR, and the first induced remission rate (CR1) was calculated, the differences of lymphocyte subsets and activated T cells in MDS patients with different immunophenotype, different WT1 expression, and different course of disease were analyzed. The percentage of CD4+T lymphocyte in MDS-EB-2, IPSS high-risk, CD34+ cells >10%, and patients with CD34+CD7+ cell population and WT1 gene overexpression at intial diagnosis decreased significantly (P<0.05), and the percentage of NK cells and activated T cells increased significantly (P<0.05), but there was no significant difference in the ratio of B lymphocytes. Compared with the normal control group, the percentage of NK cells and activated T cells in IPSS-intermediate-2 group was significantly higher(P<0.05), but there was no significant difference in the percentage of CD3+T, CD4+T lymphocytes. The percentage of CD4+T cells in patients with complete remission after the first chemotherapy was significantly higher than in patients with incomplete remission(P<0.05), and the percentage of NK cells and activated T cells was significantly lower than that in patients with incomplete remission (P<0.05). In MDS patients, the proportion of CD3+T and CD4+T lymphocytes decreased, and the proportion of activated T cells increased, indicating that the differentiation type of MDS is more primitive and the prognosis is worse.

Regulation of the Signal-Dependent E Protein HEBAlt Through a YYY Motif Is Required for Progression Through T Cell Development.

The E protein transcription factors E2A and HEB are critical for many developmental processes, including T cell development. We have shown that the Tcf12 locus gives rise to two distinct HEB proteins, with alternative (HEBAlt) and canonical (HEBCan) N-terminal domains, which are co-expressed during early T cell development. While the functional domains of HEBCan have been well studied, the nature of the HEBAlt-specific (Alt) domain has been obscure. Here we provide compelling evidence that the Alt domain provides a site for the molecular integration of cytokine signaling and E protein activity. Our results indicate that phosphorylation of a unique YYY motif in the Alt domain increases HEBAlt activity by 10-fold, and that this increase is dependent on Janus kinase activity. To enable in vivo studies of HEBAlt in the T cell context, we generated ALT-Tg mice, which can be induced to express a HA-tagged HEBAlt coding cassette in the presence of Cre recombinases. Analysis of ALT-Tg mice on the Vav-iCre background revealed a minor change in the ratio of ISP cells to CD8+ SP cells, and a mild shift in the ratio of T cells to B cells in the spleen, but otherwise the thymus, spleen, and bone marrow lymphocyte subsets were comparable at steady state. However, kinetic analysis of T cell development in OP9-DL4 co-cultures revealed a delay in early T cell development and a partial block at the DN to DP transition when HEBAlt levels or activity were increased. We also observed that HEBCan and HEBAlt displayed significant differences in protein stability that were resolved in the thymocyte context. Finally, a proteomic screen identified STAT1 and Xpo1 as potential members of HEBAlt-containing complexes in thymocytes, consistent with JAK-induced activation of HEBAlt accompanied by translocation to the nucleus. Thus, our results show that the Alt domain confers access to multiple layers of post-translational control to HEBAlt that are not available to HEBCan, and thus may serve as a rheostat to tune E protein activity levels as cells move through different thymic signaling environments during T cell development.

Status of Natural Killer Cell Recovery in Day 21 Bone Marrow after Allogeneic Hematopoietic Stem Cell Transplantation Predicts Clinical Outcome

Rapid immune recovery following allogeneic hematopoietic stem cell transplantation (allo-HSCT) is important for clinical outcome prediction. In most studies, immune recovery after allo-HSCT is monitored via peripheral blood. However, few reports regarding the status of absolute lymphocyte subsets in the bone marrow (BM) microenvironment have been undertaken. Therefore, we evaluated the clinical impact of immune recovery in the early period following allo-HSCT using BM samples. We showed that delayed natural killer cell recovery was independently associated with a poor prognosis for overall survival (hazard ratio [HR], 3.07; 95% confidence interval [CI], 1.37- 6.89; P = .007), progression-free survival (HR, 3.42; 95% CI, 1.47-7.94; P = .004), and nonrelapse mortality (HR, 6.68; 95% CI, 1.82-25.0; P = .004) by multivariate analysis. In addition, low NK cell counts were associated with the presence of 1 or more bacterial, viral, or fungal infections. Our results indicate that investigating absolute lymphocyte subsets in BM in the early phase following allo-HSCT can be useful for predicting and improving survival outcomes.

Evidence of bone marrow downregulation in brain-dead rats.

Experimental findings support the evidence of a persistent leucopenia triggered by brain death (BD). This study aimed to investigate leucocyte behaviour in bone marrow and blood after BD in rats. BD was induced using intracranial balloon catheter inflation. Sham-operated (SH) rats were trepanned only. Thereafter bone marrow cells were harvested every six hours from the femoral cavity and used for total and differential counts. They were analysed further by flow cytometry to characterize lymphocyte subsets, granulocyte adhesion molecules expression and apoptosis/necrosis [annexin V/propidium iodide (PI) protocol]. BD rats exhibited a reduction in bone marrow cells due to a reduction in lymphocytes (40%) and segmented cells (45%). Bone marrow lymphocyte subsets were similar in BD and SH rats (CD3, P=0.1; CD4, P=0.4; CD3/CD4, P=0.4; CD5, P=0.4, CD3/CD5, P=0.2; CD8, P=0.8). Expression of L-selectin and beta2 -integrins on granulocytes did not differ (CD11a, P=0.9; CD11b/c, P=0.7; CD62L, P=0.1). There were no differences in the percentage of apoptosis and necrosis (Annexin V, P=0.73; PI, P=0.21; Annexin V/PI, P=0.29). In conclusion, data presented suggest that the downregulation of the bone marrow is triggered by brain death itself, and it is not related to changes in lymphocyte subsets, granulocyte adhesion molecules expression or apoptosis and necrosis.

The Comparative Analysis of Bone Marrow Lymphocyte Subsets in Children with Acute Lymphoblastic Leukemia, Rhabdomyosarcoma, and Ewing’s Sarcoma

Russian and foreign literature presents insufficient data about the bone marrow immune system of children under normal and pathological conditions (acute leukemia (AL) and solid tumors). The aim of the research was to study the quantitative characteristics of bone marrow lymphocytes subpopulations in children with developing acute leukemia and small round cell sarcomas (rhabdomyosarcoma (RMS) and Ewing’s sarcoma family tumors (ESFT). Materials and methods. The study included 111 children aged 9 months to 17 years (mean age – 7.6±0.4 years). Rhabdomyosarcoma was diagnosed in 16 children, Ewing’s sarcoma (CIO) — in 16 children, acute lymphoblastic leukemia (ALL) — in 38 children, and acute myeloid leukemia (AML) — in 26 children. Malignancy was excluded basing on complex assessment in 15 cases (experimental group). All patients underwent cytological and immunological examination of bone marrow. Results. Typical change in the bone marrow subpopulations of patients with both types of sarcomas was the increase in the percentage of CD3+HLADR+ and CD8+HLADR+ T-cells and the decrease in the percentage of Leu8+CD4+ T cells versus the control group data (p 0.05). Comparison of bone marrow lymphocytes subpopulations in ALL and AML patients demonstrated the significant differences only in the percentage of CD19+ and CD19+CD5+ B cells, the value was significantly lower in AML patients (13.4%±1.8% vs 19.5±2.1, p=0.033 and 2.2%±0.5% vs 4.7±0.8, p=0.016, respectively). The percentage of CTLs was proportionately lower under AL than sarcomas, the maximum relative content of CD8 + T cells was revealed in the bone of RMS patients. The T-helper cells content in all four treatment groups did not significantly differ in relative and absolute values (p>0.05). Conclusions. Comprehensive morphological and immunological examination results demonstrated that these cancers are characterized by specific changes in subpopulation content of T and B bone marrow lymphocytes that revealed their clinical and prognostic value, the mechanisms of interaction between the tumor and the immune system, and may be useful in the development of immunotherapy programs.

Proportions of bone marrow lymphocyte subsets at diagnosis may predict survival in patients with newly diagnosed diffuse large B‐cell lymphoma independently of the international prognostic index

There is substantial evidence to support that the immune system plays a role in the outcome of lymphoma. For a long time, it is known that lymphoma can regress spontaneously, [1] and immunotherapy such as interferon and vaccine have some activity against the disease [2,3]. More recently, several studies in diffuse large B-cell lymphoma (DLBCL) have shown the potential value of the assessment of peripheral blood absolute lymphocyte count (PBALC) as well as nonmalignant lymphocyte subsets in the blood and the lymph node obtained at diagnosis in predicting clinical outcome [4-12]. Finally, molecular profiling of DLBCL show that genes associated with lymph node signature (host response) are predictive of overall survival (OS) independent of the commonly used International Prognostic Index (IPI) [13]. These studies of the effect of immune system on DLBCL have focused primarily on the blood and lymph node but not the bone marrow. In our retrospective study, we showed that that a higher proportion of total T-cells in the bone marrow as measured by flow cytometry was predictive of a better OS and disease-specific survival (DSS) independent of IPI in patients with newly diagnosed DLBCL treated with anthracycline-based chemotherapy. In contrast to previous studies, we did not find PBALC to have predictive importance. As bone marrow aspiration and biopsy is generally performed as part of DLBCL staging, enumeration of bone marrow lymphocyte subsets by flow cytometry may provide additional prognostic information in patients with newly diagnosed DLBCL and deserves further investigation.

Proportions of Bone Marrow Lymphocyte Subsets Predict Survival in Patients with Newly Diagnosed Diffuse Large B-Cell Lymphoma Independent of International Prognostic Index

Background: Previous studies on lymphocyte subsets in blood and lymph node suggest that host immune status at diagnosis may predict a better outcome in patients with diffuse large B-cell lymphoma (DLBCL). Since bone marrow is a major part of the host immune system and bone marrow biopsy is routinely performed as part of staging work-up in DLBCL, we studied the prognostic significance of bone marrow lymphocyte subsets at diagnosis as determined by flow cytometry in patients with DLBCL.Methods: All DLBCL patients diagnosed and treated at our institution from 2000– 07 were identified through our cancer registry. We included all patients who had flow cytometric analyses of their bone marrow aspirates at the time of diagnosis. Patients with HIV, concurrent low grade lymphoma, Richter's transformation, and DLBCL arising from the central nervous system and skin were excluded. We examined the significance of the following variables in predicting overall and disease-specific survival: International Prognostic Index (IPI) score (0–1,2, 3, or 4–5), chemotherapy received [rituximab/cyclophosphamide/doxorubicin/prednisone (R-CHOP), CHOP, or others], absolute lymphocyte count in the blood, and proportions total lymphocyte and lymphocyte subsets [B-cells (CD19+), total T-cells (CD3+), helper-T cells (CD3+/CD4+), cytotoxic-T cells (CD3+/CD8+), and NK-cells (CD16+/CD56+)] in the bone marrow. We used the method of Contal and O'Quigley to determine cut-off points for lymphocyte subsets.Results: Eighty five patients met the study criteria and were included. The mean age at diagnosis was 65 years (range, 31–97) and 60% were males. IPI distribution was 12%, 25%, 22%, 26% and 15% for scores of 0, 1, 2, 3, and 4, respectively. Most patients received either RCHOP (62%) or CHOP (28%) chemotherapy. Only 7% had bone marrow involvement by DLBCL. Univariate analysis showed that lower IPI scores, treatment with CHOP±R, and higher proportions of bone marrow total lymphocytes, B-cells, T-cells (total and subsets), and NK-cells, but not absolute lymphocyte count in the blood, were associated with better overall and disease specific survival. When evaluated in a multivariate model (Table), higher proportion of total T-cells, lower IPI scores, and treatment with CHOP±R were significant independent predictors of better overall and disease specific survival. Higher proportion of NK-cells was a significant predictor of better disease-specific but not overall survival.Conclusion: The presence of higher proportions of T-cells and NK-cells in the bone marrow predicts a better prognosis in patients with DLBCL independent of IPI score and treatment received. These findings support the importance of the role of host immune system in modulating the clinical course of DLBCL even in the era of rituximab-based treatment. If our findings are confirmed, routine assessment of bone marrow lymphocyte subsets at diagnosis in conjunction with IPI may provide a better prediction of clinical outcome in patients with DLBCL.VariablesOverall SurvivalDisease-Specific SurvivalHR95% CIPHR95% CIPHigher CD3+ cells (>5.096%)0.260.12–0.560.00070.200.07–0.580.003Higher CD16+/56+ cells (>0.584%)0.330.13–0.800.01IPI score 0–30.370.16–0.850.020.270.11–0.650.004Chemo: CHOP±R0.150.06–0.36<0.00010.100.03–0.31<0.0001

Influence of bone marrow graft lymphocyte subsets on outcome after HLA-identical sibling transplants.

The aim of this study was to analyze bone marrow lymphocyte subsets and CD34 cell dose and their influence on the outcomes of bone marrow transplantation. Forty-eight patients (median age 30 years, range 5-54) receiving HLA-identical sibling bone marrow transplantation for hematologic malignancies were analyzed. Median number (range) of nucleated cells and CD34+ cells infused were 2.4 (0.4-6.0) x 10(8)/kg and 3.5 (0.5-13.0) x 10(6)/kg, respectively. Probability of neutrophil recovery was 97%. In a multivariate analysis, time to neutrophil recovery was shortened when a higher number of CD3/CD8 cells was infused (> or =1.0 x 10(7)/kg) (hazard ratio [HR] = 2.13, p = 0.018); when the patient was female or had negative cytomegalovirus serology (HR = 2.03, p = 0.03; HR = 0.41, p = 0.009; respectively). The incidence of grade II to IV acute graft-vs-host disease (GVHD) was 47%. Infusion of >1 x 10(7) CD4 infused/kg increased the risk of acute GVHD (HR = 2.86, p = 0.03). Nineteen of 40 patients at risk experienced chronic GVHD, the risk of which was increased by diagnosis of chronic leukemia (p = 0.03), <2.0 x 10(8) nucleated cells infused/kg (p = 0.05), and a low number of all lymphocyte subsets, except CD19. Estimated 3-year survival rate was 54%. Risk of death was increased in patients receiving <3.5 x 10(6)CD34 infused/kg (HR = 0.37, p = 0.02). Only six patients relapsed. A high cell dose of CD3/CD8 is associated with faster neutrophil recovery, whereas a high cell dose of CD4+ cells increases the incidence of acute GVHD. A high number of nucleated cells and CD34+ cells infused was associated with decreased risk of chronic GVHD and improved survival, respectively.

Age-related changes of lymphocyte subsets in normal bone marrow biopsies.

There is a paucity of information in the literature concerning the age-related changes of the lymphocyte subsets in bone marrow (BM), and the available reports disagree about the characteristics of the population studied and the methods for obtaining, handling, and analyzing the samples. The purpose of the present study was to determine the distribution of lymphoid subsets in the BM from infants, children, and adults by analyzing fragments of sternum obtained during cardiovascular surgery. The samples were studied by flow cytometry employing the whole blood lysis method and excluding from the analysis the contamination of the lymphoid window by erythroid precursors. We observed that in the first 4 years of life the B subset represented more than 65% of all cells in the lymphoid window, most of them (80%) exhibiting the immature phenotype CD19+CD100+. Conversely, the T subset was composed of mature CD4+ or CD8+ cells, with the CD4/CD8 ratio being less than 1 in all age groups. With age there was a progressive decrease in the percentage of B cells and an increase of T cells, reaching similar proportions in the BM from adults (33.6% and 34.8%, respectively). Furthermore, the percentage of CD10+ cells in the B subset decreased independently, whereas the CD20 expression increased. The percentage of NK cells did not change with age.

Distribution of lymphocyte subsets in bone marrow and peripheral blood is associated with haptoglobin type. Binding of haptoglobin to the B-cell lectin CD22.

Haptoglobin is an acute phase protein showing a genetic polymorphism with 3 major types: Hp 1-1, Hp 2-1, and Hp 2-2. In this study, flow cytometric analysis demonstrated that all three haptoglobin types bind to CD22 on human B-lymphocytes with equal affinity. Comparison of reference values for lymphocyte subsets in peripheral blood and bone marrow showed significant differences between haptoglobin types. Haptoglobin 2-2 is associated with higher peripheral B-lymphocyte counts (P < 0.001) and CD4+ T-lymphocyte counts (P < 0.05). In bone marrow, CD4+ T-cell percentages were highest (P < 0.001) but B-cell percentages were lowest (P < 0.001) in haptoglobin 2-2 type. A negative correlation between serum haptoglobin 1-1 concentration and peripheral B-cell counts was observed (r = -0.663). Our results suggest that haptoglobin is involved in lymphocyte distribution. The present findings are a potential cause of over- or underestimation of lymphocyte subset counts in the clinical staging of immunodeficiency diseases.

Investigation of bone marrow lymphocyte subsets in normal, reactive, and neoplastic states using paraffin-embedded biopsy specimens.

Bone marrow lymphocyte subsets in normal and reactive states and in neoplastic diseases involving the marrow were investigated with a select panel of monoclonal antibodies reactive on routinely processed, paraffin-embedded trephine biopsy material. In all cases, the antibodies beta F1 and UCHL1 (CD45RO) stained virtually equal numbers of T cells (reactive and neoplastic), whereas antibody OPD4 stained only about one half of this number of T cells. Antibody L26 (CD20) stained B cells (reactive and neoplastic) in all specimens. The T-cell to B-cell ratio in the normal marrow was between 4:1 and 5:1, and a significant increase in T-cell numbers was observed in reactive and myelodysplastic states. A significant increase in B-cell numbers, however, was seen only in marrow infiltrated by B-cell lymphoma. Bone marrow exhibiting infiltrates of B-cell lymphoma, acute leukemia, or myeloproliferative disorders showed normal or decreased numbers of T cells. These findings show that antibodies UCHL1, beta F1, and L26 can be used to determine the numbers of B and T lymphocytes in paraffin-embedded, formalin-fixed bone marrow specimens and thus may help to distinguish reactive T lymphocytosis from B-cell lymphoma.

B-Cell Precursors in Normal Pediatric Bone Marrow

A number of studies have been published pertaining to "normal" lymphocyte subsets in bone marrow. However, these studies are based on normal adult marrow or marrows of children with leukemia in remission or other systemic illness. Data on hematologically normal children are lacking. This study demonstrates that, compared with that of adults, bone marrow of hematologically normal children has an increased percentage of B cells and B-cell precursors. Dual-parameter flow cytometric methods demonstrated subpopulations of B cells at various stages of differentiation; the percentage of cells in these subsets is highest in the very young and decreases with increasing age. Caution must be exercised when searching for early leukemic relapse in pediatric marrows because these normal immature B-cell precursors immunophenotypically resemble leukemic blasts.

Peripheral blood and bone marrow lymphocyte subsets in patients with multiple myeloma

A panel of monoclonal antibodies (McAb) from the Wu series was used to characterize lymphocyte subsets of peripheral blood (PB) from 9 patients with multiple myeloma (MM) by means of indirect immunofluorescence assay. In 7 of these patients bone marrow (BM) cells were also studied. Abnormal distribution of T lymphocyte subsets was observed in these patients, and the alterations were quite similar in both PB and BM. A significant increase in the proportion of WUT8+ cells (P less than 0.001) and a reduced WuT4/WuT8 ratio (P less than 0.001) were found in patient group. In both PB and BM of patients, WuT10+ cell counts were significantly higher than normal (P less than 0.001). There was a good correlation between BM WuT10+ cells and BM myeloma cells (r = 0.76, P less than 0.05), whereas no correlation was found between PB WuT10+ cells and BM myeloma cells. The significance of abnormal T-cell subset distribution and elevated WuT10+ cells in MM is discussed.