CD38 as a prognostic marker in CLL

Cell-surface expression of CD38 in CLL has been recognised recently as a marker of progressive disease and poor outcome. In contrast to traditional staging systems, CD38 is able to identify progressive cases at an early stage. Measurement of CD38, in conjunction with other novel prognostic factors such as p53 and ZAP-70 helps to identify patients who might benefit from early and more intensive therapy. In addition, CD38 positivity can predict unmutated IgVH gene mutation status in most cases. These features, together with its easy applicability, render CD38 a valuable tool in the routine diagnostics of CLL. Questions remaining to be clarified about CD38 include the incidence and significance of its variations during the course of the disease, the optimal method to define CD38 positivity and the impact of different methodologies on results. Only after these issues are resolved can the definitive place of CD38 be defined in the diagnostics of CLL.

The Effect of Tetraethylenepentamine, a Synthetic Copper Chelating Polyamine, on Expression of CD34 and CD38 Antigens on Normal and Leukemic Hematopoietic Cells

We have previously found that the synthetic polyamine tetraethylenepentamine (TEPA) significantly delayed differentiation and prolonged expansion of cord-blood derived HPC in cytokine-supplemented cultures. Most HPC have the CD34+CD38+ phenotype, but the minority CD34+38- cells are primitive subset of HPC that have the potential for long-term repopulation in vivo. We investigated the effect of TEPA on the CD34/CD38 surface antigen expression of human myeloid leukemia cell lines as well as normal cord blood derived hematopoietic cells. Confirming previous results, our data showed that both the leukemic and normal cells increased their CD38 expression when grown in serum-containing medium or when treated with retinoic acid. In the present study, we found that TEPA inhibited CD38 under these conditions in both normal and leukemic cells. As for CD34, TEPA increased the proportion of CD34 cells in short- and long-term normal cultures but not in the leukemic cell lines. These results suggest that ex vivo expansion of HPC depends on the presence of CD34+CD38- cells and that TEPA prolongs HPC expansion by inhibiting the CD38- to CD38+ transition.

Erythrocyte CD38 as a prognostic marker in cancer

BACKGROUND

Surface antigen CD38 which is a multifunctional protein with enzymatic and receptorial properties is involved in many processes of cell proliferation and activation. It is widely expressed within the hematopoetic system, and its expression is stimulated by proinflammatory cytokines. CD38-associated enzymatic activities in erythrocytes from cancer patients were investigated in this context.

METHODS

Erythrocyte NAD glycohydrolase and ADP-ribosyl cyclase activities in normal individuals and cancer patients were compared and correlation of these activities to CEA values and anemia were determined. Changes in CD38-expression were followed by SDS-PAGE and Western blot analysis of erythrocyte membrane proteins.

RESULTS

Erythrocyte NAD glycohydrolase and ADP-ribosyl cyclase activities were significantly increased in cancer, in parallel to enhancement of CD38 expression and in correlation with CEA values and anemia.

CONCLUSIONS

An increased expression of CD38 which may be due to action of proinflammatory cytokines produced in tumor-host reactions appears to account for the elevations in erythrocyte CD38-associated enzyme activities in cancer patients. The changes in these enzyme activities may provide a prognostic outlook in view of their apparently close correlation to tumor progressions.

Lymphotoxin-independent expression of TNF-related activation-induced cytokine by stromal cells in cryptopatches, isolated lymphoid follicles, and Peyer's patches

Stromal cells play a crucial role in the organogenesis of lymphoid tissues. We previously identified VCAM-1(+) stromal cells in cryptopatches (CP) and isolated lymphoid follicles (ILF) in the small intestine of C57BL/6 mice. Nonhemopoietic stromal cell networks in CP and ILF of adult mice also expressed FDC-M1, CD157 (BP-3), and TNF-related activation-induced cytokine (TRANCE). Individual stromal cells were heterogeneous in their expression of these markers, with not all stromal cells expressing the entire set of stromal cell markers. Expression of VCAM-1, FDC-M1, and CD157 on CP stromal cells was absent in alymphoplasia mice deficient in NF-kappaB-inducing kinase (NIK) and NIK knockout mice. Administration of lymphotoxin beta receptor (LTbetaR)-Ig to wild-type mice on day 13 resulted in the absence of CP on day 20; delaying administration of LTbetaR-Ig until day 18 resulted in an 80% decrease in the number of CP on day 22 and diminished expression of VCAM-1, FDC-M1, and CD157 on the remaining CP. In sharp contrast, TRANCE expression by stromal cells was completely independent of NIK and LTbetaR. In addition, expression of TRANCE in ILF was concentrated just beneath the follicle-associated epithelium, a pattern of polarization that was also observed in Peyer's patches. These findings suggest that TRANCE on stromal cells contributes to the differentiation and maintenance of organized lymphoid aggregates in the small intestine.

Mesenchymal lineage precursor cells induce vascular network formation in ischemic myocardium

Mesenchymal lineage precursors can be reproducibly isolated from adult mammalian bone marrow and grown in culture. Immunoselection with monoclonal antibodies against STRO-1 and vascular-cell-adhesion molecule 1 (VCAM1/CD106) prior to expansion results in a 1,000-fold enrichment of mesenchymal precursors compared to standard isolation techniques. Intramyocardial injection of human STRO-1-selected precursors in an athymic rat model of acute myocardial infarction results in induction of vascular network formation and arteriogenesis coupled with global functional cardiac recovery.

High stem cell frequency in acute myeloid leukemia at diagnosis predicts high minimal residual disease and poor survival

PURPOSE

In CD34-positive acute myeloid leukemia (AML), the leukemia-initiating event originates from the CD34(+)CD38(-) stem cell compartment. Survival of these cells after chemotherapy may lead to minimal residual disease (MRD) and subsequently to relapse. Therefore, the prognostic impact of stem cell frequency in CD34-positive AML was investigated.

EXPERIMENTAL DESIGN

First, the leukemogenic potential of unpurified CD34(+)CD38(-) cells, present among other cells, was investigated in vivo using nonobese diabetic/severe combined immunodeficient mice transplantation experiments. Second, we analyzed whether the CD34(+)CD38(-) compartment at diagnosis correlates with MRD frequency after chemotherapy and clinical outcome in 92 AML patients.

RESULTS

In vivo data showed that engraftment of AML blasts in nonobese diabetic/severe combined immunodeficient mice directly correlated with stem cell frequency of the graft. In patients, a high percentage of CD34(+)CD38(-) stem cells at diagnosis significantly correlated with a high MRD frequency, especially after the third course of chemotherapy. Also, it directly correlated with poor survival. In contrast, total CD34(+) percentage showed no such correlations.

CONCLUSIONS

Both in vivo data, as well as the correlation studies, show that AML stem cell frequency at diagnosis offers a new prognostic factor. From our data, it is tempting to hypothesize that a large CD34(+)CD38(-) population at diagnosis reflects a higher percentage of chemotherapy-resistant cells that will lead to the outgrowth of MRD, thereby affecting clinical outcome. Ultimately, future therapies should be directed toward malignant stem cells.

Interleukin-4 up-regulates T-tropic human immunodeficiency virus type 1 transcription in primary CD4+ CD38+ T-lymphocyte subset

The capacity of human immunodeficiency virus type 1 (HIV-1) to infect resting cells and to produce progeny particles may contribute significantly to its pathogenicity in vivo. We previously reported that primary culture of resting CD4(+) CD38(+) T-lymphocyte subset had higher production rate of CXCR4-using (X4) HIV-1 than CD4(+) CD38(-) subset. Interleukin (IL)-4 highly contributed to the up-regulation of the X4 virus production in the CD38(+) subset. Here, we show evidences that IL-4 treatment of both resting CD38(+) and CD38(-) subsets allowed the adsorption, entry, and integration of X4 virus at similar rates, while the following viral transcription rate was significantly lower in the CD38(-) than CD38(+) subset. Treatment of the CD38 subsets with IL-4 or phytohemagglutinin revealed no association of X4 virus replication ability in the subsets with classic T-cell activation or proliferation. Interestingly, the activator protein (AP)-1 was significantly activated in the CD38(+) subset after IL-4 treatment, while both nuclear factor (NF)-kappaB and signal transducers and activator of transcription (STAT)-6 were activated in the IL-4-treated CD38(-) and CD38(-) subsets at similar levels. Thus, IL-4-dependent X4 HIV-1 transcription occurs efficiently in the CD38(+) but not CD38(-) subset of CD4(+) population and AP-1 could play a significant role on viral transcription, leading to the up-regulated X4 virus production in the CD38(+) subset.

The maturation of myeloma cells correlates with sensitivity to chemotherapeutic agents

We analyzed both morphologic and phenotypic findings of myeloma cells before and after chemotherapy in 21 patients with multiple myeloma. The morphologic analysis was based on the Greipp classification, and phenotypic analysis was performed by 3-color flow cytometry using the CD38 plasma gating method (Marrow plasma 38). Results with flow cytometry using a combination of MPC1, CD49e, and CD45 supported the morphologic findings for the myeloma cells. Treatment with 3 or 4 cycles of VAD (vincristine, doxorubicin, and dexamethasone) therapy was effective in reducing the total numbers of myeloma cells, but the proportion of immature myeloma cells increased after this treatment. However, the immature myeloma cells were reduced by high-dose melphalan (HD-Mel) therapy followed by autologous stem cell transplantation (ASCT). High-dose cyclophosphamide treatment for stem cell harvesting did not show an effect on the residual immature myeloma cells after VAD treatment. In addition, thalidomide was not effective in reducing the numbers of immature myeloma cells. These results suggest that VAD (3 or 4 cycles) therapy plus HD-Mel followed by ASCT is a reasonable treatment for multiple myeloma and that Marrow plasma 38 analysis is a useful method for monitoring the response of multiple myeloma to chemotherapy.

Combined analysis of ZAP-70 and CD38 expression as a predictor of disease progression in B-cell chronic lymphocytic leukemia

Prognostic predictions in B-cell chronic lymphocytic leukemia (B-CLL) at early clinical stage are based on biological disease parameters, such as ZAP-70 and CD38 protein levels, genomic aberrations as well as immunoglobulin variable heavy chain gene (IgV(H)) mutation status. In the current study, ZAP-70 and CD38 expressions were examined by flow cytometry in 252 patients with B-CLL. Cytoplasmic ZAP-70 expression in more than 20% (ZAP-70(+)) and surface CD38 expression on more than 30% (CD38(+)) of B-CLL cells were associated with an unfavorable clinical course. The levels of ZAP-70 and CD38 did not change over time in the majority of patients where sequential samples were available for analysis. Combined analysis of ZAP-70 and CD38 yielded discordant results in 73 patients (29.0%), whereas 120 patients (47.6%) were concordantly negative and 59 patients (23.4%) were concordantly positive for ZAP-70 and CD38 expression. Median treatment-free survival times in patients whose leukemic cells were ZAP-70(+)CD38(+) was 30 months as compared to 130 months in patients with a ZAP-70(-)CD38(-) status. In patients with discordant ZAP-70/CD38 results, the median treatment-free survival time was 43 months. Thus, ZAP-70 and CD38 expression analyses provided complementary prognostic information identifying three patient subgroups with good, intermediate and poor prognosis. Over-representation of high-risk genomic aberrations such as 17p deletion or 11q deletion and distribution of the IgV(H) mutation status in B-CLL discordant for ZAP-70/CD38 pointed toward a distinct biologic background of the observed disease subgroups. This finding was also supported by microarray-based gene expression profiling in a subset of 35 patients. The expression of 37 genes differed significantly between the three groups defined by their expression of ZAP-70 and CD38, including genes that are involved in regulation of cell survival and chemotherapy resistance.

Plasmacellular differentiation in extranodal marginal zone B cell lymphomas of the ocular adnexa: an analysis of the neoplastic plasma cell phenotype and its prognostic significance in 136 cases

AIM

To determine (a) the expression of plasma cell related antigens in extranodal marginal zone B cell lymphomas (EMZL) of the ocular adnexa; and (b) the prognostic value of plasmacellular differentiation in these tumours.

METHODS

A consecutive case series of 136 ocular adnexal EMZL obtained from three ocular pathology centres over 20 years was analysed retrospectively. An extensive immunohistochemical panel, including the plasma cell related antigens VS38c, CD38, CD138, multiple myeloma oncogene-1-protein (MUM1/IRF4), and CREB binding protein (CBP) was performed. EMZL were defined as "plasmacellular differentiated" on the basis of morphological features, evidence of cytoplasmic immunoglobulin, negativity for BSAP/PAX5, and expression of at least one of the investigated plasma cell related antigens. Controls included normal or hyperplastic lymphatic tissues. Detailed clinical data were collected for most patients, and compared with the results of immunohistochemistry. The end points considered for statistical analysis were development of local tumour recurrence, development of systemic disease, and lymphoma related death.

RESULTS

57 (42%) of the 136 ocular adnexal EMZL showed a plasmacellular differentiation; 45 of these plasmacytoid cases were primary tumours. In contrast with most admixed normal plasma cells, which displayed co-expression of MUM1/IRF4, Vs38c, CD38, CD138, and CBP, the plasmacellular differentiated EMZL tumour cells demonstrated co-expression of all five plasma cell related antigens in only six of 57 (11%) plasmacellular differentiated ocular adnexal EMZL. The most commonly expressed plasma cell related antigen was MUM1/IRF4, immunoreactivity being seen in 56/57 (98%) plasmacellular differentiated EMZL examined. Although the association of plasmacellular differentiation in primary ocular adnexal EMZL and disseminated disease was statistically significant on univariate analysis (p = 0.042), this was weaker on multivariate analysis.

CONCLUSION

Plasmacellular differentiated tumour cells in EMZL demonstrate an aberrant immune profile for plasma cell related antigens when compared with normal plasma cells. On multivariate analysis, plasmacellular differentiation in ocular adnexal EMZL was not significantly associated with local recurrence, the development of systemic disease, or with lymphoma related death.

Role of the second-messenger cyclic-adenosine 5'-diphosphate-ribose on adrenocorticotropin secretion from pituitary cells

We examined the role of the second-messenger cyclic-ADP-ribose (cADPR) on the regulation of ACTH secretion using AtT20 corticotroph tumor cell line. We found that the cADPR antagonist, 8-Br-cADPR, substantially diminished the secretion of ACTH induced by CRH and potassium in these cells, whereas xestospongin C, an inositol 1,4,5-triphosphate receptor antagonist, had no effect. In addition, the cADPR agonist, 3-deaza-cADPR, augmented ACTH secretion. The presence of the components of the cADPR system, namely ryanodine receptor, CD38, and cADPR itself, was determined in AtT20 cells. Furthermore, we observed that antagonists of the ryanodine channel and cADPR system can decrease the potassium-induced Ca2+ transients in these cells. These results suggest that cADPR is a second messenger in pituitary cells and regulates ACTH secretion by a mechanism dependent on activation of the ryanodine channel by extracellular Ca2+.

Pre-clinical evaluation of the malaria vaccine candidate P. falciparum MSP1(42) formulated with novel adjuvants or with alum

We compared the safety and immunogenicity of the recombinant Plasmodium falciparum MSP1(42) antigen formulated with four novel adjuvant systems (AS01B, AS02A, AS05 and AS08) to alum in rhesus monkeys. All five formulations of MSP1(42) were safe and immunogenic. Whereas, all MSP1(42) formulations tested generated high stimulation indices for lymphocyte proliferation (ranging from 27 to 50), the AS02A and AS01B formulations induced the highest levels of specific anti-MSP1(42) antibody. ELISPOT assays showed that the AS02A and AS01B vaccine formulations-induced different cytokine response profiles. Using the ratio of IFN-gamma/IL-5 secreting cells as the metric, the AS01B formulation induced a strong Th1 response, whereas the AS02A formulation induced a balanced Th1/Th2 response. The IFN-gamma response generated by AS02A and AS01B formulations persisted at least 24 weeks after final vaccination. The notable difference in Th1/Th2 polarization induced by the AS02A and AS01B formulations warrants comparative clinical testing.

Karyotyping, immunophenotyping, and apoptosis analyses on human hematopoietic precursor cells derived from umbilical cord blood following long-term ex vivo expansion

By means of flow cytometry, CD34+/CD38- hematopoietic stem cells (HSC) were collected from umbilical cord blood (UCB) of 10 healthy women at the time of delivery and cultivated in stem-cell culture media supplemented with cell growth stimulating factors (IL-3, IL-6, GM-CSF, EPO, IGF-1, and SCF) for long periods. Apoptotic status, cell surface marker expression, and karyotypes of the cultured UCB-derived CD34+/CD38- stem-cells were investigated by flow cytometry and GTG-banding methods. The UCB-derived CD34+/CD38- stem-cells were able to divide and proliferate in vitro for at least 6 months. They did not show significantly increased apoptosis following ex vivo expansion for 20 and 32 days, respectively, in 2 cases and retained the same cell surface marker expression pattern (i.e., CD34+ and CD38-) in the majority of the cells of 2 cases following 20 and 37 days of incubation, respectively. In another 2 cases, chromosome analysis showed no evidence of numerical and structural abnormalities in the CD34+/CD38- stem-cells obtained after 20 and 43 days in culture, respectively. Our findings indicated that UCB-derived CD34+/CD38- stemcells are able to maintain their basic biologic and genetic characteristics after dividing and proliferating in vitro for a long period of time. UCB-derived HSC following ex vivo expansion can serve as a reliable resource for hematopoietic precursor cells transplantation.

Downregulation of CXCR5 in CD27- B cells of HIV-1 infected patients

The CD27(-) (naive) B cells of HIV-1 infected patients have been shown to be increased in frequency and to be activated, as indicated by high CD38 expression on the cell surface. CXCR5, a B cell chemokine receptor, is expressed on circulating CD27(-) (naive) B cells and plays a pivotal role in peripheral B cell development. To investigate the effect of HIV-1 infection on the expression of this chemokine receptor on naive B cells, the expression level of CXCR5 on CD27(-) B cells was examined in 19 drug-naive HIV-1 infected patients, 27 HAART-treated patients, and 20 controls. CXCR5 expression on CD27(-) B cells was significantly lower in drug-naive patients than in HAART-treated patients and controls (P < 0.01). CD27(-) B cells with high CD38 expression exhibited low CXCR5 expression. The CXCR5 expression level on CD27(-) B cells recovered to within the normal range after effective antiretroviral therapy. These findings suggested that HIV-1 infection induces a remarkable phenotypic alteration of naive B cells and that the activated naive B cells found in HIV-1 infection downregulate CXCR5 on their surface. Impaired homing of naive B cells may contribute to HIV-1 induced immunological deficiencies.

Evi3, a zinc-finger protein related to EBFAZ, regulates EBF activity in B-cell leukemia

Retroviral insertions that activate proto-oncogenes are a primary cause of tumors in certain strains of mice. The AKXD recombinant inbred mice are predisposed to a variety of leukemias and lymphomas as a result of viral integration. One common insertion site, the ecotropic viral insertion site 3 (Evi3), has been implicated in most B-cell tumors in the AKXD-27 strain. The Evi3 gene encodes a zinc-finger protein with sequence similarity to the Early B-cell Factor-Associated Zinc-finger gene (EBFAZ). We show that the Evi3 gene is overexpressed in several tumors with viral insertions at Evi3, which results in the upregulation of Early B-cell Factor (EBF)-target gene expression, suggesting that Evi3 modulates EBF activity. Reconstitution of primary leukemia cells showed that these tumors express high densities of the B-cell surface proteins CD19 and CD38, which are EBF targets. Using a transactivation assay, we show that the terminal six zinc-fingers of Evi3 are required for modification of EBF activity. This is the first evidence that Evi3 expression in tumors alters the level of EBF target genes, and the first characterization of the Evi3 protein domains required for modulation of EBF activity. Further, these data imply that Evi3 misexpression initiates tumorigenesis by perturbing B-cell development via an interaction with EBF.

Flow cytometric evaluation of bone marrow plasma cells using CD19, CD45, CD56, CD38, and CD138 and correlation with bone marrow infiltration ratio in multiple myeloma patients

OBJECTIVE

To examine the co-expression of CD19, CD45, CD38, CD56, and CD138 molecules in plasma cells of bone marrow (BM) aspirates and their relation with BM infiltration, and treatment in patients with multiple myeloma by flow cytometry.

METHODS

Forty BM aspirate samples were assessed from 40 patients at diagnosis and on follow-up at the Medical Oncology Department, Cukurova University, Balcali Hospital, Turkey, between 2002 and 2004. The mean age was 56.83 +/- 9.1 and male:female ratio was 2.6. All patients received at least 4 courses of VAD(vincristine, adriamycin, dexamethasone) regimens and 20 of them were also treated with high dose melphalan and peripheral autologous stem cell transplantation. The median follow-up period was 19.1 +/- 22.7 months.

RESULTS

Using light microscopy the BM smears stained with hematoxylin and eosin from patients on follow up were classified into one of 3 categories, complete remission (CR) (<5%), partial remission (PR) (>5% and <30%), and extensive infiltration (EI) (>30%). According to infiltration ratio 23 were evaluated CR, 2 were PR and 15 were EI. The mean value of CD19 was 6.01 +/- 9.5%, CD56 = 9.9 +/- 6.8%, CD138 = 8.6 +/- 5.6%, CD45 = 84.2 +/- 22.3% and CD38 = 59.5 +/- 25.4%. The flow cytometric analyses revealed that only the mean value of CD38 and CD45 expression were significantly high. We correlated infiltration ratio with each parametric and found statistically significant relations. We also correlated independent variables with each other and found a relation between CD38 and CD19 (p=0.005). We also defined the groups whether treated with peripheral autologous transplantation or not and compared the independent variables between them, in which CD138 was statistically significant (p=0.02).

CONCLUSION

We suggest BM plasma cells expressed mainly by CD38 and CD45 may have a role in generation of BM plasma cells and that CD138 expression may be considered in follow-up for minimal residual disease after autologous transplantation in myeloma patients.

In multiple myeloma clonotypic CD38- /CD19+ / CD27+ memory B cells recirculate through bone marrow, peripheral blood and lymph nodes

It is believed that myeloma cells are derived from a germinal center (GC) or post GC B cell. The GC B cell can differentiate into both a memory B cell and a plasma cell (PC). In this study, we investigated the recirculating potential of memory B cells clonally related to the myeloma PC (termed clonotypic). The V(H)DJ(H) immunoglobulin gene rearrangement of the myeloma clone was identified for 10 myeloma patients and allele-specific oligonucleotides (ASO) IgH RT-PCR assays were designed for each patient. Memory B cells (CD38- /CD19+ /CD27+) and their subsets defined by the monoclonal antibodies CD62L, CCR6, CXCR4, CXCR5, CCR7 were flow-sorted as single cells and analyzed by ASO RT-PCR analysis. In addition, aspirated peripheral lymph nodes (PLN) of 7 myeloma patients in complete or partial remission were analyzed for the presence of clonotypic cells. Circulating clonotypic memory B cells were identified in PBMNC of 7/10 patients and both CD62L positive and negative clonotypic memory B cells were identified. Furthermore, comparable frequencies of clonotypic cells were found in the CCR6 +/- and CXCR4 +/- memory B cell subsets, whereas all clonotypic memory and later stage B cells were CXCR5 positive. In accordance with their immunophenotype, clonotypic memory B-cells were identified in peripheral blood, bone marrow and PLNs. Clonotypic memory B-cells were present in the majority of myeloma patients and seem to have the same diverse recirculating/homing capacity as normal memory B cells.

[CD38 antigen as a marker for immunological follow-up in HIV-positive patients]

BACKGROUND

HIV infection causes chronic activation of cytotoxic CD8+ T-lymphocytes, which is partly responsible for the hallmark of the disease--progressive loss of CD4+ T-lymphocytes. The aim of this study was to evaluate an influence of HIV infection and long-term antiretroviral therapy (HAART) on expression of the activation molecules CD38 on CD8+ T-lymphocytes.

METHODS

A group of 16 HIV-positive patients treated with HAART was followed for 12 months. Also, we examined 10 persons with a newly diagnosed HIV infection that were not treated with HAART. Expression of CD38 molecules on CD8+ T-lymphocytes was determined with five-parameter cytometric analysis using monoclonal antibodies as well as their mean fluorescence intensity (MFI).

RESULTS

The percentage of CD8+/CD38+ T-lymphocytes in HIV-positive patients treated with HAART significantly decreased during the follow-up period from 46.1 I 3.7 to 35.2 I 3.8 (p = 0,01). Furthermore, the percentage of these cells correlated negatively with the number of CD4+T-lymphocytes at the beginning and the end of the study (r = -0,679, p < 0.01; r = -0,51, p = 0,05, respectively). There was no correlation between these parameters in persons with newly diagnosed HIV infection. However, the percentage of CD8+/CD38+ T-lymphocytes in these patients was significantly higher than in persons treated with HAART (68.5 I 5.3 vs. 35.2 I 3.8, p < 0,01).

CONCLUSIONS

Our findings support the importance of expression of CD38 antigen on CD8+ T-lymphocytes as a biological and clinical marker of HIV infection and indicate its usefulness for monitoring of the efficacy of HAART therapy.

Tracking the follicular lymphoma cells in flow cytometry: characterisation of a new useful antibody combination

OBJECTIVES

Follicular lymphoma (FL) is the most common adult non-Hodgkin's lymphoma. Diagnosis is based on morphology and can be confirmed by cytogenetic, flow cytometry (FCM) or molecular studies. Despite all these complementary approaches, diagnosis sometimes remains difficult. The purpose of the present work was to characterise the expression of new specific follicular cells markers which allows us to target specifically the abnormal FL cell population in FCM.

METHODS

A total of 153 samples from healthy subjects and from patients with chronic B-cell lymphoproliferative disorders were analysed by FCM in the same conditions for purpose of comparison.

RESULTS

We showed that CD44 is weakly expressed in FL cells compared with peripheral blood mononuclear cell from normal blood donors and others cells from B lymphoproliferative diseases. We nevertheless observed bone marrow samples where some immature B-cell population express CD44 with lower fluorescence intensity. Therefore, we developed a double antibody combination, using CD44 and CD38, which allowed us to separate the normal immature cells from the pathological population using FCM.

CONCLUSION

This new phenotypic approach offers an accurate (sensitivity and specificity of 93% and 96%, respectively), fast and low sample consuming method for the diagnosis of FL.

The relation between bone marrow angiogenesis and the proliferation index Ki-67 in multiple myeloma

AIM

Angiogenesis correlates with disease progression in various haematological malignancies. This study investigated the association between microvascular density (MVD) and the Ki-67 proliferation index (Ki-67 PI), bone marrow infiltration, and C reactive protein (CRP) in patients with multiple myeloma.

METHODS

Bone marrow MVD was examined in 44 biopsies at diagnosis and 15 in plateau phase by immunostaining the endothelial cells with a monoclonal antibody to CD34. The Ki-67 PI was evaluated by a double immunostaining technique using the monoclonal antibodies MIB-1 and CD38.

RESULTS

MVD, Ki-67 PI, bone marrow infiltration, and CRP were significantly higher in pretreatment patients than in controls and decreased in patients achieving plateau phase. MVD significantly correlated with Ki-67 PI and infiltration, and Ki-67 correlated with infiltration.

CONCLUSION

In multiple myeloma, apart from being a marker of proliferative activity, Ki-67 is also associated with bone marrow angiogenesis and tumour burden.

t(1;14) and t(11;18) in the differential diagnosis of Waldenström's macroglobulinemia

Waldenström's macroglobulinemia is caused by several B-cell proliferative disorders including lymphoplasmacytic lymphoma, marginal zone B-cell lymphoma, B-cell chronic lymphocytic leukemia and multiple myeloma. Differential diagnosis between lymphoplasmacytic lymphoma and extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue is particularly difficult as there is a considerable overlap in histological presentation. We report a case of Waldenström's macroglobulinemia with involvement of the peripheral blood, bone marrow and stomach. Serum chemistry revealed an IgM of 5.4 g/dl, but Bence-Jones protein in urine was negative. Abnormal lymphoid cells were detected in both blood and the bone marrow. Flow cytometry of the bone marrow aspirate showed that majority of cells were CD20(+), CD38(+), expressing immunoglobulin lambda light chain, but CD5(-) and CD10(-). Gastric biopsies revealed infiltration of the gastric mucosa by small lymphoid cells showing plasmacytoid differentiation and occasional Dutcher bodies. Lymphoepithelial lesions and Helicobacter pylori were not seen. Thus, the differential diagnosis between lymphoplasmacytic lymphoma and mucosa-associated lymphoid tissue lymphoma was raised. To resolve this, we performed BCL10 immunohistochemistry and reverse transcriptional polymerase chain reaction (RT-PCR) for the API2-MALT1 fusion transcript of t(11;18)(q21;q21). Both bone marrow and gastric biopsies showed strong BCL10 nuclear staining, similar to that seen in t(1;14)(p22;q32) positive mucosa-associated lymphoid tissue lymphoma, but absence of the API2-MALT1 fusion transcript. To further ascertain whether the detection of t(1;14)(p22;q32) and t(11;18)(q21;q21) can be reliably used for the differential diagnosis between lymphoplasmacytic lymphoma and mucosa-associated lymphoid tissue lymphoma, we screened for these translocations by BCL10 immunohistochemistry in 58 lymphoplasmacytic lymphomas and RT-PCR for t(11;18)(q21;q21) in 40 lymphoplasmacytic lymphomas, respectively. None of the lymphoplasmacytic lymphomas studied harbored these translocations. Thus, detection of t(1;14)(p22;q32) and t(11;18)(q21;q21) is useful in the differential diagnosis between lymphoplasmacytic lymphoma and mucosa-associated lymphoid tissue lymphoma.

[New perspectives in the evolution of prognosis and treatment of chronic lymphocytic leukaemia]

Chronic lymphocytic leukaemia is a disease with a variable clinical course and prognosis. New prognostic factors like immunoglobulin gene mutational status, cytogenetic abnormalities, CD38 and ZAP70 expression of malignant cells have been described recently. Conventional and biological prognostic factors allow to identify patients with unfavorable prognosis at early stage. Purin analogues, fludarabine and fludarabine based combinations can achieve complete hematological remission in approximately one third of patients with chronic lymphocytic leukaemia. Chemoimmunotherapy (most experience is obtained by combination of fludarabine + cyclophosphamide + rituximab) can increase not only complete remission rate, but also induce molecular remission in some cases. Stem cell transplantation as well as early and effective chemotherapy are curative choices of treatment in patients with chronic lymphocytic leukaemia.

Immunological and virological study of enfuvirtide-treated HIV-positive patients

OBJECTIVE

To evaluate the predictive value and evolution of immunological and virological parameters related to HIV entry and pathogenesis in patients receiving enfuvirtide (ENF) plus an optimized regimen.

METHODS

A phase III clinical trial substudy of ENF in 22 patients measured virus coreceptor use and sensitivity to ENF, levels of chemokines, cytokines and chemokine receptors, CD38 and HLA-DR expression as markers of T cell activation and ex vivo cell death at baseline and at week 32.

RESULTS

Treatment including ENF reduced HIV viral load (P < 0.001) and increased the CD4 cell count in patients that responded (RP) to treatment (n = 14). Significant (P < 0.05) increases were noted in the RP group in CXCR4 and CCR5 expression in CD4 cells without major differences in chemokine and interleukin-7 levels. A decrease in CD38 expression in the absence of HLA-DR changes was observed in CD4 cells. Apoptosis of peripheral blood mononuclear cells was significantly reduced in the RP group. Coreceptor use or ENF sensitivity of virus isolated at baseline was not associated with virus resistance or response to treatment, which appeared to be related to the activation state (HLA-DR expression) of CD4 cells at baseline.

CONCLUSION

The outcome of ENF-containing treatment could not be associated with HIV coreceptor use at baseline. CD4 cell activation and viral drug resistance were the only markers of treatment response. Changes induced by ENF-containing regimen were seen in HIV coreceptor expression, including an increase in CCR5+CD4+ cells, a decrease in CD38 T cells and a concomitant reduction of T cell apoptosis.

Expansion of HPCs from cord blood in a novel 3D matrix

BACKGROUND

An optimal system for the expansion of pluripotent HPCs would ideally eliminate the use of cytokines and animal-derived serum. We have shown previously that a 3D, tantalum-coated porous biomaterial (Cytomatrix) supports the maintenance and expansion of human BM HPCs in the absence of cytokines.

METHODS

Umbilical cord blood (UCB) derived HPC were cultured in the Cytomatrix in the absence of exogenous cytokines. Phenotype was determined using FACS. Colony-forming units (CFU) activity was evaluated. Engraftment capacity was evaluated by transplanting the expanded cells into non-obese diabetic (NOD)/SCID mice.

RESULTS

We describe the expansion of HPCs from UCB using the Cytomatrix system. When UCB-derived CD34(+) cells were cultured in the Cytomatrix system for 2 weeks we observed an increase in the number of nucleated cells (3-fold) and CFU (2.6-fold). The number of CD45(+) and CD34(+) cells both increased three-fold. Trends demonstrated an increase in the frequency of CD34(+)C38(-) cells, and an increase in both CD34(+)C33(+) cells and CD34(+)C61(+) cells. No expansion of T or B lymphocytes was observed. When expanded UCB cells from the Cytomatrix were injected into sub-lethally irradiated NOD/SCID mice, human cells were detected in the murine peripheral blood and BM 6 weeks post-transplantation.

DISCUSSION

This unique approach to the expansion of UCB cells in a serum-free, cytokine-free environment may provide expansion of HPCs with multi-lineage engraftment capability that could be used clinically.

The prognostic value of CD38 expression and its quantification in B cell chronic lymphocytic leukemia (B-CLL)

A large number of prognostic factors are available to help predict the outcome of patients who present with B-cell chronic lymphocytic leukemia (B-CLL). These include clinical stage, leukemic cell morphology, lymphocyte doubling time, the pattern of infiltration in bone marrow trephine biopsies, cytogenetic abnormalities, p53 function and serum factors such as beta-2 microglobulin. Two recently described major prognostic factors are immunoglobulin heavy chain variable region (IgVH) mutation status and cell membrane expression of CD38. These are both highly significant independent prognostic factors, but are not closely correlated. Whereas IgVH mutational status is a time consuming and demanding technique, only available in a limited number of centres, CD38 expression by flow cytometry is relatively simple and rapidly obtained in most diagnostic laboratories. The predictive value of CD38 expression is enhanced by measurement of antigen density in terms of antibody binding capacity (ABC) rather than as the percentage of cells expressing the antigen. ABC correlates closely with relative median fluorescence (RMF), a parameter which is even more simply and cheaply obtained by flow cytometry. One of these methods of determining CD38 expression should be employed routinely. Recent work suggests that membrane ZAP-70 expression determined by flow cytometry will prove to be an accurate proxy for IgVH mutational status and this assay will be within the reach of any laboratory skilled in flow cytometry. The combination of ZAP-70 expression, CD38 antigen density, p53 function and the concentration of serum factors such as soluble CD23, is likely to provide extremely accurate prognostic information in future studies. This will assist in identifying Stage A patients who may benfit from early and/or more intensive treatment, as well as Stage B and C patients who may require alternative treatment strategies at the outset.

The use of CD38 expression by monoclonal B lymphocytes as a prognostic factor in B-cell chronic lymphocytic leukemia

In B-cell chronic lymphocytic leukemia (B-CLL) the Rai and Binet staging criteria are not always able to accurately predict the prognosis of each patient. Rapidly evolving, violent disease is often seen in the so-called "good-prognosis" group, which highlights the need of additional and more refined prognostic markers. Several of these markers are described in the literature, with varying abilities to predict patient survival. Among the promising prognostic markers is flowcytometric analysis of CD38 on the monoclonal B cells in CLL. Several studies have shown that expression of CD38 is associated with a decreased overall-, or progression free survival. CD38 expression may be analyzed as percentage positive cells or as antibodies bound per cell. Addition of CD38 to the flow cytometry antibody panel for B-CLL analysis is a relatively easy way to obtain important prognostic information.

Telomere length in subpopulations of human hematopoietic cells

In order to test the hypothesis that the telomere length in human hematopoietic cells correlates with their proliferative potential, we analyzed the telomere length in highly purified subpopulations of bone marrow cells. Cells were sorted on the basis of CD34 and CD38 cell surface markers, and two samples were additionally sorted on the basis of Hoechst 33342 dye efflux allowing isolation of side population (SP) cells. The telomere length in limiting numbers of sorted cells was analyzed using a newly developed fluorescence in situ hybridization (flow-FISH) method in which hybridization of telomere probe in cells of interest is measured relative to control cells in the same tube. In all seven bone marrow samples analyzed, the telomere length in CD34(+)CD38(-) cells was longer than in CD34(+)CD38(+) cells from the same donor (p < 0.02). Results with sorted SP cells were less clear: the telomere fluorescence in these cells was very heterogeneous, and a reproducible difference in telomere length relative to CD34(+)CD38(-) cells could not be observed. We conclude that the telomere length in subpopulations of hematopoietic cells does appear to be correlated with the known proliferative potential of such cells and that further characterization of cells on the basis of telomere length is warranted for enrichment of very rare precursors of hematopoietic and other tissues.

Human CD34(+) and CD34(+)CD38(-) hematopoietic progenitors in sickle cell disease differ phenotypically and functionally from normal and suggest distinct subpopulations that generate F cells

OBJECTIVE

Sickle cell disease (SCD) is remarkable for stress erythropoiesis. We investigated the progenitor populations contributing to erythroid stress.

MATERIALS AND METHODS

We characterized hematopoietic progenitor cells in sickle bone marrow and sickle peripheral blood from patients with SCD compared to those in normal bone marrow.

RESULTS

There were increased proportions of sickle bone marrow and sickle peripheral blood CD34(+) cells that coexpressed glycophorin A (GlyA), normally expressed late during erythroid differentiation when CD34 is down-regulated. Remarkably, increased numbers of CD34(+)CD38(-) hematopoietic progenitor cells from sickle bone marrow (p < 0.03) and sickle peripheral blood (p < 0.004) coexpressed GlyA, compared to normal bone marrow CD34(+)CD38(-) hematopoietic progenitor cells. At a molecular level, even the sickle bone marrow and sickle peripheral blood CD34(+)CD38(-) hematopoietic progenitor cells not expressing GlyA by fluorescence-activated cell sorting or reverse transcriptase-polymerase chain reaction expressed the erythroid-specific gene GATA-1, unlike normal bone marrow, suggesting desynchronized erythroid gene expression in the SCD hematopoietic progenitor cells. We also generated red blood cells in vitro from GlyA(+) and GlyA(-)CD34(+) cells. GlyA(+)CD34(+) produced more F cells (p < 0.02) and had lower clonogenicity (p < 0.01) and erythroid expansion potential. Increased F cells were generated only from sickle CD34(+) hematopoietic progenitor cells (p < 0.04), as occurs in vivo.

CONCLUSION

Stress erythropoiesis in SCD has been postulated to accelerate erythropoiesis and production of F cells. Thus, CD34(+)CD38(-) expressing GlyA may represent the "stress progenitor" population. This is the first study characterizing CD34(+) and CD34(+)CD38(-) hematopoietic progenitor cells in sickle bone marrow, comparing them to sickle peripheral blood and normal bone marrow and using them to generate sickle red blood cells that recapitulate F cell production observed in vivo. We identified a unique population of GlyA(+)CD34(+) cells in SCD, which is in an accelerated erythroid differentiation pathway, has not down-regulated CD34 antigen expression, and predominantly generates F cells.

CD34+ cells and CD34+CD38- subset from mobilized blood show different patterns of adhesion molecules compared to those from steady-state blood, bone marrow, and cord blood

As suggested previously, a down-regulation of some cellular adhesion molecules (CAMs) on CD34(+) hematopoietic progenitor cells (HPC) may contribute to their egress from bone marrow (BM) to peripheral blood (PB) by decreasing their adhesion to BM stromal cells. Besides counting the percentage of CAM-positive cells, we decided to define clearly the antigen density (AgD) of the CAM on mobilized- and steady-state CD34(+) HPC using QIFIKIT calibration beads. Five sources of cells were compared: PB and BM from normal donors (nPB, nBM) cord blood (CB), mobilized PB obtained from leukapheresis products (LKP), and mobilized BM (mBM) samples. In our study the CAM-AgD was the lowest on CD34(+) cells in LKP which, on the contrary, contained the highest percentage of CD117(+), CD54(+), CD58(+) cell subsets. As for CB, a greater proportion of CD44(+) and CD62L(+) cells was observed in LKP than in other products. The LKP-CD34(+) cell population contained a greater percentage of CD11a(+) cells when compared to mBM, but the lowest percentage of CD49d(+) and CD49e(+) cells when compared to all products. The proportion of the CD34(+)CD38(-) immature subset expressing CD11a, CD44, CD54, or CD62L was greater in LKP than in mBM; the CD62L-AgD was higher in LKP than in mBM. This quantitative analysis clearly showed a downregulation of all CAM on LKP-CD34(+). The CD44, CD62L, CD11a, and CD54 AgD decrease appears to be specifically involved in the egress of the CD34(+) subsets into PB. The control of antigen density of these adhesion molecules is likely to be clinically important for effective mobilization of HPC as well as for rapid engraftment following HPC transplant.

Flow cytometric detection of aneuploid CD38(++) plasmacells and CD19(+) B-lymphocytes in bone marrow, peripheral blood and PBSC harvest in multiple myeloma patients

DNA aneuploidy has been used as a genetic marker of malignancy in multiple myeloma (MM). CD38 and CD138 expression and absence of CD22 and CD19 may define plasmacells (PC). Several authors support evidences of circulating plasmacells, and their role in relapse after autologous stem cell transplantation has been hypothesised. The existence of B-lymphocytes belonging to the myeloma clone is still controversial. If CD19 or CD22 positive B-lymphocytes are part of the myeloma clone, there should be evidence of myeloma-specific genetic markers in this population. Using DNA content measurement in combination with CD19 or CD38 detection in a multiparametric flow cytometry analysis, we studied bone marrow and peripheral blood of 10 aneuploid MM patients. In the bone marrows of all these 10 aneuploid patients (100%), we detected CD38(++) aneuploid plasmacells ( 27 +/- 17%, mean +/- S.D.) and a small number of CD19(+) aneuploid lymphocytes ( 0.11 +/- 0.074%). In 100% of these patients, we also detected CD38(++) aneuploid circulating plasmacells ( 0.6 +/- 0.9 %) and a small number of CD19(+) aneuploid lymphocytes (0.03 +/- 0.04%). In this study, we detected aneuploid CD19(+) lymphocytes and CD38(++) plasmacells in bone marrow and peripheral blood of all MM patients. A crucial role for the detection of aneuploid CD19(+) cells was played by the acquisition of a sufficient number of CD19(+) lymphocytes by using a "live gate" acquisition and "continuous gating" analysis. With the techniques used in this study, it was possible to detect aneuploid B lymphoid cells among normal diploid B cells. The significance of this finding is controversial and opened to different interpretations.

Increased frequency of CD27- (naive) B cells and their phenotypic alteration in HIV type 1-infected patients

To investigate HIV-1-related B cell disorders, the quantity of peripheral CD27 negative (CD27-) B cells, their CD38, CD95, and bcl-2 intensities, and their apoptosis susceptibility were examined by flow cytometry analysis in 16 drug-naive patients, 27 HAART-treated patients, and 20 uninfected controls. CD27- B cells have been recognized as naive B cells. The mean percentage of CD27- B cells was significantly higher in drugnaive patients (88.1%) and in HAART-treated patients (83.9%) than in controls (68.6%) (p < 0.01). The intensities of CD38 and CD95 on CD27- B cells were significantly higher in drug-naive patients than in controls (p < 0.01). The intensity of CD95 on CD27- B cells in HAART-treated patients was lower than that of drug-naive patients, but significantly higher than that of controls (p < 0.01). The intensity of bcl-2 on CD27- B cells in drug-naive patients was lower than that of controls. In drug-naive patients, CD27-B cells with high CD38 expression represented low bcl-2 expression. The CD27- B cells of drug-naive patients showed an increased susceptibility to apoptosis, characterized by diminished cell size and a high frequency of annexin-V binding, compared with controls and HAART-treated patients. These findings suggested that HIV-1 infection affects peripheral CD27- (naive) B cells as well as CD27+ (memory) B cells and that CD27- B cells might be activated and rendered highly susceptible to apoptosis by HIV-1 infection. Some phenotypic alterations in CD27- B cells may continue after the reduction of HIV-1 loads by effective antiviral therapy.

Serum angiogenin is not elevated in patients with early B-cell chronic lymphocytic leukemia but is prognostic factor for disease progression

The association between angiogenin and cancer progression and poor outcome in solid tumors has been documented, but its significance in leukemias has not been evaluated. Using an ELISA technique (Quantikine Human Angiogenin Immunoassay; R&D Systems), we measured serum angiogenin levels in 77 previously untreated Binet stage A B-cell chronic lymphocytic leukemia (CLL) patients. No difference in angiogenin serum levels could be found between patients (median: 295 ng/mL; range: 74-1700) and 15 age- and sex-matched healthy controls (median: 264 ng/mL; range: 29-1835) (P = NS; Mann-Whitney test). Increased angiogenin serum level was associated with higher LDH (P = 0.03) and beta2-m (P = 0.007) concentrations. However, angiogenin did not reflect the extent of bone marrow (BM) angiogenesis as evaluated by microvessel area (P = 0.611), circulating levels of vascular endothelial growth factor (VEGF) (P = 0.873) and basic fibroblastic growth factor (FGF-2) (P = 0.421). When the 25 patients with available data were stratified into the four major cytogenetic categories (normal karyotype, 13q as a sole aberration, 12q trisomy, 11q or 17p deletion) and aberrations were compared with angiogenin serum levels, no correlation was found (P = 0.651; Kruskall-Wallis test). A cut-off of angiogenin serum level corresponding to median (i.e. 330 ng/mL) or higher identified later upstaging and longer progression-free survival (PFS). The 5-yr PFS was 51.5% for patients with angiogenin levels lower than median and 85% for patients with higher values [P = 0.03; hazard ratio (HR) = 2.86; 95% CI: 1.08-6.72]. Although in multivariate analysis only Rai substages (P = 0.00001) and peripheral blood lymphocytosis (P = 0.009) retained their prognostic significance, angiogenin could be incorporated into the Rai substages thus leading to the identification of the following risk categories: (i) stage 0 (angionenin >330 ng/mL); (ii) stage 0 (angiogenin <330 ng/mL) + stage I-II (angiogenin >330 ng/mL); and (iii) stage I-II (angiogenin <330 ng/mL). The 40-month PFS were as follows: 85%, 65%, 25% (chi(2) for trend = 6.33; d.f. = 1; P = 0.01). In conclusion, serum angiogenin levels although not increased in comparison with healthy controls, may predict clinical outcome of patients with early CLL and help to refine Rai's stratification.

Arthropathies and thyroid diseases

AIM

Improvement of articular symptoms following thyroidectomy has often been observed in patients with an association of thyroid and joint diseases. An assessment has therefore been made of the types of arthropathy thus benefited and the anatomopathological features of the thyroid in patients with concomitant joint diseases. An account is given of the arthropathies associated with nontoxic nodular goitre (NTG).

METHODS

Three cell markers are examined to identify immunocytokine elements differentiating thyroid diseases.

RESULTS

Immunohistochemical examination shows extravasal lymphocyte infiltrates; thyrocytes were negative for HLA-Cl II, CD38 and IL-6R, and only dim-positive for HLA-Cl I. Endothelial cells were positive for HLA-Cl I and II and CD38, and negative for IL-6R. The lymphocyte were positive for HLA-Cl I, HLA-Cl II and CD38, but negative for IL-6R. The follow-up of 6 thyroidectomised patients disclosed improvement in joint pain and remission of rheumatoid arthritis and spondylarthritis. Association of nodular goitre with arthro-pathies is demonstrated.

CONCLUSION

Arthritis and arthralgia are frequent in patients with thyroid diseases, we particularly found the association with MHNG and Hurthle cell adenoma. Arthritis and arthralgia quickly improve after thyroidectomy. Immunohistochemical NTG thyrocytes are still normal cells (HLA-Cl II negative) by contrast with their HLA-Cl II positivity in autoimmune thyroiditis.

Preferential expression of the vasoactive intestinal peptide (VIP) receptor VPAC1 in human cord blood-derived CD34+CD38- cells: possible role of VIP as a growth-promoting factor for hematopoietic stem/progenitor cells

Primitive hematopoietic progenitor cells such as severe combined immunodeficiency- repopulating cells and long-term culture-initiating cells are enriched in CD34+CD38- cells derived from various stem cell sources. In this study, to elucidate the features of such primitive cells at the molecular level, we tried to isolate genes that were preferentially expressed in umbilical cord blood (CB)-derived CD34+CD38- cells by subtractive hybridization. The gene for VPAC1 receptor, a receptor for the neuropeptide vasoactive intestinal peptide (VIP), was thereby isolated and it was shown that this gene was expressed in both CD34+CD38- and CD34+CD38+ CB cells and that the expression levels were higher in CD34+CD38- CB cells. Next, we assessed the effects of VIP on the proliferation of CD34+ CB cells using in vitro culture systems. In serum-free single-cell suspension culture, VIP enhanced clonal growth of CD34+ CB cells in synergy with FLT3 ligand (FL), stem cell factor (SCF), and thrombopoietin (TPO). In serum-free clonogenic assays, VIP promoted myeloid (colony-forming unit-granulocyte/macrophage (CFU-GM)) and mixed (CFU-Mix) colony formations. Furthermore, in Dexter-type long-term cultures, VIP increased colony-forming cells at week 5 of culture. These results suggest that VIP functions as a growth-promoting factor of CB-derived hematopoetic progenitor cells.

1513A/C polymorphism in the P2X7 receptor gene in chronic lymphocytic leukemia: absence of correlation with clinical outcome

Purinergic P2X7 receptors are ligand-gated cation channels expressed on the cells of the immune and hemopoietic system which have been shown to mediate the ATP-induced apoptotic death of monocytes, macrophages and lymphocytes. A common single nucleotide polymorphism within the P2X7 gene has been described in exon 13 (1513A/C), the gene products encoding fully active and non-functional proteins. We genotyped the P2X7 1513A/C polymorphism using DNA from 111 patients with chronic lymphocytic leukemia (CLL) and 97 healthy controls using polymerase chain reaction (PCR) amplification followed by Hha1 restriction analysis. We found no significant difference in allele frequency between CLL patients and controls. Time periods from diagnosis to initiation of chemotherapy, a surrogate marker for disease progression, were not different in patients displaying the combined 1513A/C and C/C or the 1513A/A genotype (P = 0.97). Similar results were observed in a subgroup analysis of prognostically more favorable CD38-negative and ZAP-70-negative CLL patients. In conclusion, our data do not support a role of the P2X7 genotype as a prognostic marker in B-cell CLL.

Neutralization of autocrine transforming growth factor-beta in human cord blood CD34(+)CD38(-)Lin(-) cells promotes stem-cell-factor-mediated erythropoietin-independent early erythroid progenitor development and reduces terminal differentiation

Transforming growth factor (TGF)-beta1 exerts autocrine and paracrine effects on hematopoiesis. Here, we have attempted to evaluate the effect of endogenous TGF-beta1 on early erythroid development from primitive human hematopoietic stem cells (HSCs) and to assess the effects of TGF-beta1 on different phases of erythropoiesis. Cord blood CD34(+)CD38(-) lineage-marker-negative (Lin(-)) cells were cultured in serum-free conditions using various combinations of stem cell factor (SCF), erythropoietin (Epo), and TGF-beta-neutralizing antibody. Generation of erythroid progenitors was assessed using colony assay and flow cytometry. Terminal erythroid differentiation was examined when SCF/Epo-stimulated cells were recultured in the presence of Epo with and without TGF-beta1. Anti-TGF-beta augmented the proliferation of CD34(+)CD38(-)Lin(-) cells (day 21) in SCF-stimulated (6.4-fold +/- 1.5-fold) and SCF/Epo-stimulated (2.9-fold +/- 1.2-fold) cultures. Cells stimulated by SCF/Epo underwent similar levels of erythroid differentiation with and without anti-TGF-beta. While SCF alone stimulated the production of tryptase-positive mast cells, cells stimulated by SCF/anti-TGF-beta were predominantly erythroid (CD36(+)CD14(-) and glycophorin A positive). A distinct expansion of erythroid progenitors (CD34(+)CD36(+)CD14(-)) with the potential to form erythroid colonies was seen, revealing early Epo-independent erythroid development. In contrast, the kinetics of erythroid progenitor generation from primitive HSCs indicate that TGF-beta1 is not inhibitory in late erythropoiesis, but it accelerated the conversion of large BFU-E into colony-forming units-erythroid. Finally, TGF-beta1 accelerated Epo-induced terminal erythroid differentiation and resulted in a greater level of enucleation (22% +/- 6% versus 7% +/- 3%) in serum-free conditions. Serum addition stimulated enucleation (54% +/- 18%), which was lower (26% +/- 14%) with anti-TGF-beta, suggesting that optimal erythroid enucleation is Epo dependent, requiring serum factors including TGF-beta1.

An imbalance of naive and memory/effector subsets and altered expression of CD38 on T lymphocytes in two girls with hyper-IgM syndrome

In this report we evaluated CD4(+) T, CD8(+) T and natural killer (NK) cell counts, the levels of naive/memory subsets within the CD4(+) T lymphocyte population, expression of CD38 on T lymphocytes, and CD4(+) and CD8(+) T cell cytokine production in two girls with hyper-IgM (HIM) syndrome. Both girls developed recurrent infections early in infancy, presenting a wide spectrum of clinical manifestations, with a strikingly different disease severity between them. CD4(+) T cell counts were low in both children (patient 1: 214 cells/mm(3) and patient 2: 392 cells/mm(3)), and the CD4/CD8 T cell ratio was 0.4 for patient 1, the patient with the more severe disease, and 1.4 for patient 2. NK cell numbers were low in patient 1 (60 cells/mm(3)) and borderline (286 cells/mm(3)) with regard to normal levels in patient 2. An imbalance of naive and memory/effector cell subsets was found in both girls, with the percentage of CD45RA(+) 27(+) (naive) CD4(+) T lymphocytes being 5.8 and 12.4 for patients 1 and 2, respectively. Expression of CD38 on the surface of T lymphocytes was low in patient 1. Detection of intracellular interferon (IFN)-gamma and tumour necrosis factor (TNF)-alpha in CD4(+) and CD8(+) T lymphocytes upon PMA-Io stimulus was preserved in both children. In conclusion, we found low numbers of CD4(+) T lymphocytes and a dramatic redistribution of naive and memory/effector CD4(+) T lymphocytes in two girls with non-X-linked HIM syndrome. Furthermore, we found low expression of CD38 on T lymphocytes and low numbers of NK cells in the patient with the more severe disease, indicating a possible role for these cells in the pathogenesis of this immunodeficiency.

Expression of the chemokine receptors CXCR4 and CCR7 and disease progression in B-cell chronic lymphocytic leukemia/ small lymphocytic lymphoma

OBJECTIVE

To assess the clinical relevance of chemokine receptor expression on the progression of B-cell chronic lymphocytic leukemia (B-CLL).

PATIENTS AND METHODS

Peripheral blood mononuclear cells from 45 patients with B-CLL were purified and compared with lymph node samples collected from 17 of these patients. Also compared were B cells obtained from peripheral blood samples from 5 healthy controls and B cells from reactive lymph nodes from 3 otherwise healthy persons. The patients were treated at the Mayo Clinic in Rochester, Minn, between January 15,1991, and February 7, 2003. Mononuclear cells were stained by a 2-color (fluorescein isothiocyanate/phycoerythrin) flow cytometric assay using antibodies to the chemokine receptors (CXCR1, CXCR2, CXCR3, CXCR4, CXCR5, CCR2, CCR4, CCR5, CCR6, and CCR7) and also to CD19.

RESULTS

Of the 45 patients in this study, 20 had Rai stage 0 disease, 12 had stage I disease, 3 had stage II disease, 2 had stage III disease, and 8 had stage IV disease. The mean fluorescent intensity (MFI) of the chemokine receptor expression on B-CLL cells was compared with normal controls and was not significantly different, except for an increase in the median expression of CXCR3 (P = .003) and CCR7 (P = .001) on B-CLL cells. We also found a significant increase in the expression of CXCR4 and CCR7 in B-CLL cells from patients with stage IV compared with stage 0 disease (P = .001 and P = .02, respectively). Furthermore, circulating B-CLL cells showed significantly higher expression of CXCR4 and CCR7 when compared with B lymphocytes in lymph nodes (P = .003 and P < .001, respectively).

CONCLUSION

The expression of CXCR4 and CCR7 on B-CLL cells correlates with Rai stage. Also, these chemokine receptors may be down-regulated once malignant B cells enter the lymph nodes. To our knowledge, this is the first published report that shows the strong association of Rai stage with CXCR4 and CCR7 expression levels in B-CLL cells.

Membrane-bound Delta-4 Notch ligand reduces the proliferative activity of primitive human hematopoietic CD34+CD38low cells while maintaining their LTC-IC potential

To examine the role of the Notch ligand Delta-4 on hematopoietic stem cells, human CD34+CD38low cord blood cells were cocultured on S17 cells transduced with transmembrane Delta-4 (mbD4/S17) or an empty vector (C/S17). By the end of a 3-week culture, mbD4/S17 induced a 25-fold reduction in nucleated cell production, as compared to C/S17, by maintaining a higher proportion of cells in G0/G1 phase. A specific retention of a high proportion of CD34+ cells throughout the culture was observed with mbD4/S17, contrary to C/S17. Although mbD4/S17 promoted expansion of cells with the phenotype of committed lymphoid precursors (CD34+CD7+CD45RA+), these cells still retained their myeloid differentiation potential. mbD4/S17 maintained a higher LTC-IC frequency in output CD34+ cells, compared to C/S17, as in the subsets of cells having completed the same number of divisions on mbD4/S17. A Delta4-Fc protein (extracellular part of human Delta4 fused to Fc human IgG1 portion), immobilized on plastic, also reduced cell production and retained the LTC-IC potential. Transplantation of cells grown on mbD4/S17 into NOD/SCID mice showed no significant enhancement of the long-term repopulating ability. Thus, Delta4 appears to inhibit hematopoietic stem cell proliferation, in association with the maintenance of short-term lymphoid and myeloid repopulation capacity.

The role of cyclic-ADP-ribose-signaling pathway in oxytocin-induced Ca2+ transients in human myometrium cells

Human myometrial contraction plays a fundamental role in labor. Dysfunction of uterine contraction is an important cause of labor progression failure. Although the mechanisms controlling uterine contraction are not completely understood, intracellular Ca2+ mobilization plays an important role during uterine contraction. Several mechanisms of intracellular Ca2+ mobilization are present in smooth muscle, but in the human uterus, only 1,4,5-trisphosphate-induced Ca2+ release has been studied extensively. Ryanodine receptor channels are present in myometrium. We determined the role of the cyclic ADP-ribose (cADPR)-signaling pathway in oxytocin-induced intracellular Ca2+ [(Ca2+)i] transients in human myometrial cells. We found that oxytocin-induced Ca2+ transient is dependent on several sources of Ca2+, including extracellular Ca2+ and intracellular Ca2+ stores. In addition, we found that both the 1,4,5-trisphosphate- and the cADPR-induced Ca2+ releasing systems are important for the induction of [Ca2+]i transients by oxytocin in human myometrial cells. Furthermore, we investigated TNFalpha regulation of oxytocin-induced [Ca2+]i transients, CD38 cyclase activity, and CD38 expression in human myometrial cells. We found that oxytocin-induced [Ca2+]i transients were significantly increased by 50 ng/ml TNF. Similarly, CD38 mRNA levels, CD38 expression, and cyclase activity were increased by TNFalpha, thus increasing cADPR levels. We propose that a complex interaction between multiple signaling pathways is important for the development of intracellular Ca2+ transients induced by oxytocin and that TNFalpha may contribute for the myometrium preparation for labor by regulating the cADPR-signaling pathway. The observation that the cADPR-signaling pathway is important for the development of intracellular Ca2+ transients in human myometrial cells raises the possibility that this signaling pathway could serve as a target for the development of new therapeutic strategies for abnormal myometrial contraction observed during pregnancy.

Expression of activation molecules in neutrophils, monocytes and lymphocytes from patients with unstable angina treated with stent implantation

Coronary angioplasty is known to mediate an inflammatory response. Recently, we have characterized the transient systemic inflammatory response after coronary stent implantation in patients with unstable angina by measuring different soluble protein markers. In the present study we have characterized the expression of various cellular activation markers in neutrophils, monocytes and lymphocytes from the same group of patients. Peripheral blood samples were taken before and 24 h, 48 h and 7 days after successful coronary stenting in 58 patients. Cell surface markers (CD11b/CD18 and CD38) were analyzed by flow cytometry to determine the activation of neutrophils, monocytes and T lymphocytes. We found that coronary angioplasty with stent implantation produces an increase in the cell surface expression of CD11b/CD18 in neutrophils and CD38 in monocytes, following a similar time-course with a peak after 24 h, returning to basal levels after 48 h and a second peak after 7 days. However, T lymphocytes were not found to be activated. These results suggest that coronary stent implantation induces a different pattern inducing soluble and cellular inflammation markers, and therefore, they should be taken into account in patients undergoing stent implantation to study clinical correlations.

Correlation of c-kit expression and cell cycle regulation by transforming growth factor-beta in CD34+ CD38- human bone marrow cells

To investigate the relationship between c-kit expression and cell cycle regulation by endogenous transforming growth factor-beta (TGF-beta) in human bone marrow hematopoietic progenitor cells, CD34+ CD38- c-kit(low/-) and CD34+ CD38- c-kit(high) populations were cultured in stem cell factor, thrombopoietin, interleukin-3 (IL-3), IL-6, granulocyte colony-stimulating factor, granulocyte/macrophage colony-stimulating factor and anti-TGF-beta, and analyzed for cell cycle status. Arrest in G0/G1 was most prominent in the precultured CD34+ CD38- c-kit(low/-) subset (95.62 +/- 4.15%). While postcultured CD34+ CD38- c-kit(high) cells initiated from CD34+ CD38- c-kit(high) cells entered cell cycle within 36 hr, postcultured CD34+ CD38- c-kit(low/-) cells initiated from CD34+ CD38- c-kit(low/-) cells remained dormant until 36 hr and entered cell cycle within 90 hr. Anti-TGF-beta increased the percentage of S/G2M phase postcultured CD34+ CD38- c-kit(high) cells (from 19.08 +/- 11.95 to 47.04 +/- 2.93%), but no significant change was observed in postcultured CD34+ CD38- c-kit(low/-) cells. These results suggest that endogenous TGF-beta plays an important role in the cell cycle arrest of c-kit(high) but not c-kit(low/-) cells in CD34+ CD38- cells, which proliferate without undergoing differentiation. The different regulatory mechanism of cell cycle entry of the CD34+ CD38- c-kit(high) and CD34+ CD38- c-kit(low/-) subsets might be the result of differences in their sensitivity to endogenous TGF-beta.

Limited long-term naive CD4+ T cell reconstitution in patients experiencing viral load rebounds during HAART

Long-term (3.5 years) immune reconstitution in relation to viral load response was determined. Plasma HIV-1 RNA was suppressed in 40 patients (full responders) up to 42 months, and 17 patients achieved partial response. The measurements of CD4(+) and CD8(+) T lymphocyte subsets (CD45RA, CD45RACD62L, CD45RO, CD28, CD38) were carried out by flow cytometry. Full responders had a significant increase of CD4(+) and all CD4(+) T subsets both up to 6 and from 6 to 42 months, while the increase for partial responders was only up to 6 months. By 6 months, higher slopes were observed in full versus partial responders in the % of CD28 on CD4(+) and the % of CD4(+) memory subset and in both naïve and memory CD4(+) subsets from 6 to 42 months. The percentage of CD8(+) and its subsets was decreased significantly in full responders both up to 6 and from 6 to 42 months (except for an increase in the CD8(+)CD45RA(+) CD62L(+) cells), while in partial responders this decrease was only up to 6 months. Lower slopes were observed in full versus partial responders from 6 to 42 months in the percentages of CD8(+), CD8(+)CD45RO(+), CD8(+)CD28(-), and CD8(+)CD38(+) T cells. In conclusion, full responders have a stronger long-term naive CD4(+) T cell subset reconstitution than partial responders.

The immunologic role of thymectomy in the treatment of myasthenia gravis: implication of thymus-associated B-lymphocyte subset in reduction of the anti-acetylcholine receptor antibody titer

BACKGROUND AND PURPOSE

Thymectomy is generally accepted as the major option of treatment for myasthenia gravis. To elucidate the biological role of thymectomy in the treatment of myasthenia gravis, the immunologic characteristics of the thymus was studied in association with the postoperative kinetics of the anti-acetylcholine receptor antibody titer.

MATERIALS AND METHODS

Thirty-four patients with nonthymomatous myasthenia gravis who had positive anti-acetylcholine receptor antibody titer and undergoing extended thymectomy were subjected to the study. Reduction of anti-acetylcholine receptor antibody titer was evaluated in terms of the proportion of anti-acetylcholine receptor antibody titer at 1 year after thymectomy to that before the operation. The numbers of B lymphocytes (CD19(+) cells) and the germinal center B lymphocytes (CD19(+)CD38(high) cells) present in 1 g of the thymic tissue were calculated by flow cytometry.

RESULTS

The proportion of anti-acetylcholine receptor antibody titer at 1 year after thymectomy ranged from 27.5% to 150%. The numbers of B lymphocytes and the germinal center B lymphocytes in 1 g of the thymic tissue ranged from 0.19 x 10(6)/g to 162.8 x 10(6)/g and from 0.09 x 10(6)/g to 33.4 x 10(6)/g, respectively. The proportion of anti-acetylcholine receptor antibody titer at 1 year after thymectomy had a significant inverted correlation with the number of B lymphocytes (P =.002) as well as that of the germinal center B lymphocytes (P =.007).

CONCLUSION

Effectiveness of thymectomy was dependent on predominance of B lymphocytes and the germinal center B lymphocytes in the thymus, suggesting that one of the biological roles of thymectomy in the treatment of myasthenia gravis is removing the thymus-associated germinal centers.

[Effect of Tpo and/or IL-11 gene modified stromal cells on the expansion of CD34+ CD38- hematopoietic primitive progenitor cells]

OBJECTIVE

To investigate the effects of Tpo and/or IL-11 gene modified stromal cells on the expansion of CD(34)(+) hematopoietic stem/progenitor cells in cord blood.

METHODS

Retroviral vectors containing Tpo or IL-11 gene were constructed and used to transfect the stromal cell line HFCL. Tpo and/or IL-11 mRNA was assayed by Northern blot. Non-modified stromal cells were used, CD(34)(+) hematopoietic stem/progenitor cells from cord blood were expanded on gene-modified stromal cells for 7 days. The phenotype of CD(34)(+)CD(38)(-) primitive progenitors was detected by flow cytometry.

RESULTS

HFCL expressed Tpo and/or IL-11 mRNA after transfected by the retroviral vectors. The percentages of CD(34)(+)CD(38)(-) primitive progenitors in the cultures of Tpo, IL-11 and Tpo + IL-11 modified HFCL were (1.8 +/- 0.24)%, (1.62 +/- 0.23)%, and (2.45 +/- 0.28)%, respectively, which were higher than that in the control [(0.8 +/- 0.23)%].

CONCLUSION

The stromal cells modified by Tpo and/or IL-11 gene were able to enhance ex vivo expansion of CD(34)(+) and CD(34)(+)CD(38)(-) hematopoietic stem/progenitor cells from cord blood.

Hemopoietic progenitor cells and bone marrow stromal cells in patients with autoimmune hepatitis type 1 and primary biliary cirrhosis

BACKGROUND/AIMS

Autologous hematopoietic stem cell transplantation has been used in severe cases of autoimmunity. We investigated whether hemopoietic progenitor cells and/or bone marrow (BM) microenvironment are affected in autoimmune hepatitis type-1 (AIH-1) and primary biliary cirrhosis (PBC).

METHODS

We studied 13 AIH-1 patients, 13 PBC patients, 12 cirrhotic controls (CC) and ten healthy controls (HC). Flow cytometry, expansion cultures, long-term BM cultures and clonogenic progenitor cell assays were used. Stromal cell function was assessed in long-term BM cultures recharged with normal CD34+ cells.

RESULTS

AIH-1 had increased CD34+, CD34+/CD38+ and CD34+/CD38- cells compared to all groups (P<0.001). PBC had lower progenitor cells compared to controls (P<0.005). No differences were found between CC and HC. Committed progenitor cells in non-adherent cell fraction were increased in AIH-1 (P<0.05) but decreased in PBC compared to controls (P<0.05). Granulocyte-macrophage colony forming units (CFU) and erythroid-burst CFU were increased in AIH-1 compared to all groups (P<0.001). PBC had these CFUs decreased compared to controls (P<0.005). Stromal cells failed to support normal hemopoiesis in PBC.

CONCLUSIONS

We demonstrated for the first time that AIH-1 had increased hemopoietic progenitor cells and normal stromal function. In PBC, progenitor cells and BM microenvironment were defective. Further studies will determine the significance of these novel findings.

Evaluation of relative anti-myeloma activity of high-dose melphalan followed by the first peripheral blood stem cell transplantation, as compared with the second transplantation, and to VAD chemotherapy

Current treatment in multiple myeloma consists of three courses of chemotherapy in low doses with subsequent hematopoietic stem cell mobilization to the peripheral blood using high-dose cyclophosphamide, collection and conditioning with high-dose chemotherapy (melphalan) followed by retransplantation of autologous peripheral blood stem cells (PBSCT). Only a few studies compare the effects of different phases of therapy on parameters, such as monoclonal immunoglobulin level and the presence of malignant CD38(+) and CD56(+) cells in blood and marrow. The aim of this study was to compare the effects of these two major phases of treatment (conventional and high dose) in the same patients, and furthermore, to compare the effects of the second course of high-dose therapy followed by PBSCT with the effects of the first one. Fifteen patients were included in the study. On average, conventional chemotherapy only slightly reduced the values of all disease markers. In contrast, high-dose therapy resulted in a dramatic effect, rapidly normalizing the values of all parameters. The effects of second PBSCT were only modest compared to the first. These data suggest that high-dose therapy is an efficient method to reduce tumor load in multiple myeloma. Conventional-dose chemotherapy may be simply a waste of time for some patients and may be either omitted or administered after high-dose therapy to consolidate remission.

Profiling of the cell surface proteome

The in depth-mining of the proteome necessitates the comprehensive analysis of proteins in individual subcellular compartments to uncover interesting patterns of protein expression that include assessment of protein location, trafficking and of post-translational modifications that are location specific. One of the compartments of substantial interest from a diagnostic and therapeutic point of view is the plasma membrane which contains intrinsic membrane proteins and other proteins expressed on the cell surface. Technologies are currently available for the comprehensive profiling of the cell surface proteome that rely on protein tagging of intact cells. Studies are emerging that point to unexpected patterns of expression of specific proteins on the cell surface, with a common occurrence of proteins previously considered to occur predominantly in other compartments, notably the endoplasmic reticulum. The profiling of the cell surface and plasma membrane proteomes will likely provide novel insights and uncover disease related alterations.

Functional CD25- and CD25+ mucosal regulatory T cells are induced in gut-draining lymphoid tissue within 48 h after oral antigen application

Oral antigen application induces tolerance, leading to suppression of a subsequent systemic challenge with this antigen. The suppression is mediated by mucosal regulatory T (Tr) cells that may differentiate from naive peripheral T cells in the gut-draining lymphoid tissue. However, little is known about the initial steps of this differentiation process. In this study we show that 48 h after oral OVA treatment, antigen-specific T cells in mesenteric lymph nodes (MLN) and Peyer's Patches (PP) were activated and had divided up to four times. The first division was already seen in PP after 24 h. Analysis of surface marker expression and cytokine secretion of the dividing antigen-specific T cells revealed that they sequentially obtained an activation- and memory-like phenotype. These cells secreted IL-2 in most stages of division but only transiently IFN-gamma whereas no IL-4 or IL-10 secretion was detected. Remarkably, 48 h after antigen application, isolated dividing cells were suppressive, as they transferred tolerance to naive mice. Even though CD25 was expressed heterogeneously, both CD25(+) and CD25(-) OVA-specific T cells from MLN could transfer tolerance. Together these findings show that differentiation of functional Tr cells occurs in the MLN and PP within 2 days after antigen ingestion and involves the generation of CD25(+) and CD25(-) antigen-specific T cells.

Increased numbers of CD38 molecules on bright CD8+ T lymphocytes in infectious mononucleosis caused by Epstein-Barr virus infection

The aim of this study was to quantify the expression of CD38 on CD8+ T lymphocytes of patients with infectious mononucleosis (IM) caused by Epstein-Barr virus (EBV) and cytomegalovirus (CMV). CD38 quantification technique chosen for this study was based on the enumeration of CD38 antibody binding sites in comparison to the quantification standards rather than determining relative fluorescence, which is difficult to standardize. The study enrolled 19 patients with typical clinical and laboratory parameters compatible with EBV-induced IM as well as 10 patients with atypical clinical presentation of this disease. Furthermore, CD38 expression was analysed in a group of 13 patients with IM caused by CMV infection. CD38 quantification was performed within 6 days of the presentation of symptoms. All three groups of IM patients showed a statistically significant increase in the number of anti-CD38 antibody binding sites (which correspond to the number of CD38 molecules) on bright CD8+ T lymphocytes compared to healthy controls. The numbers of CD38 molecules expressed on CD8+ T lymphocytes did not differ significantly between IM patients with typical and atypical clinical presentation of the disease. Patients with CMV-induced IM had significantly lower numbers of CD38 molecules expressed on CD8+ T lymphocytes. Therefore, we conclude that CD38 quantification could be helpful in differential diagnostics of IM cases with atypical clinical presentation.