Effects of platelet microparticles on the activation of B cells

Platelets are anucleated fragments derived from megakaryocytes. It has been demonstrated that platelets play a role in hemostasis and innate immunity. In addition, platelets have a CD40 ligand which is an important molecular marker in motivating immune cells. Thus, platelets also have a role in adaptive immunity as seen by their ability to activate B cells. Since human platelet microparticles [MPs] originate from platelets, we have chosen to examine the effects of MPs on B cell activation. Platelet MPs were isolated from platelet concentrates obtained from the Tehran Blood Transfusion Center. The MPs were co-cultured with B cells isolated from human whole blood with magnetic beads using negative selection. After seven days, the expression of activation markers CD27 and CD86, as well as IgD were evaluated by flow cytometry. In a comparison between test [B cells/MPs] and control [B cells] cells we observed that the expression of activation markers CD27 and CD86 increased during the seven-day co-culture period. However, the expression of IgD antibody decreased. As with platelets, MPs can affect B cell activation during in vitro co-culture

Immunophenotypic Characterization and Quantification of Neoplastic Bone Marrow Plasma Cells by Multiparametric Flow Cytometry and Its Clinical Significance in Korean Myeloma Patients

Multiparametric flow cytometry (MFC) allows discrimination between normal and neoplastic plasma cells (NeoPCs) within the bone marrow plasma cell (BMPC) compartment. This study sought to characterize immunophenotypes and quantitate the proportion of NeoPCs in BMPCs to diagnose plasma cell myeoma (PCM) and evaluate the prognostic impact of this method. We analyzed the MFC data of the bone marrow aspirates of 76 patients with PCM and 33 patients with reactive plasmacytosis. MFC analysis was performed using three combinations: CD38/CD138/-/CD45; CD56/CD20/CD138/CD19; and CD27/CD28/CD138/CD117. The plasma cells of patients with reactive plasmacytosis demonstrated normal immunophenotypic patterns. Aberrant marker expression was observed in NeoPCs, with negative CD19 expression observed in 100% of cases, CD56+ in 73.7%, CD117+ in 15.2%, CD27- in 10.5%, CD20+ in 9.2%, and CD28+ in 1.3%. In PCM patients, more than 20% of NeoPCs/BMPCs were significantly associated with factors suggestive of poor clinical outcomes. Patients who were CD27- or CD56+/CD27-, demonstrated shorter overall survival than patients of other CD56/CD27 combinations. Our results support the clinical value of immunophenotyping and quantifying NeoPCs in PCM patients. This strategy could help to reveal poor prognostic categories and delineate surrogate markers for risk stratification in PCM patients.

Significantly Higher Percentage of Circulating CD27(high) Plasma Cells in Systemic Lupus Erythematosus Patients with Infection than with Disease Flare-Up

PURPOSE: To distinguish lupus flare-up from infection in systemic lupus erythematosus (SLE), we analyze the expression of circulating CD27(high) plasma cells in SLE patients with and without infection, in comparison to non-SLE patients with infection. MATERIALS AND METHODS: The percentage of circulating CD27(high) plasma cells was measured by flow cytometry in the following four groups: 36 SLE patients without infection, 23 SLE patients with infection, eight non-SLE patients with infection, and 26 healthy controls. RESULTS: The frequency of CD27(high) plasma cells had a correlation with the SLE disease activity index (SLEDAI) (r = 0.866, p < 0.05), level of anti-dsDNA (r = 0.886, p < 0.05), C3 (r = - 0.392, p < 0.05), and C4 (r = - 0.337, p < 0.05) in SLE patients without infection, but there was no correlation with disease activity in SLE patients with infection. Among three groups in particular-SLE without infection, SLE with infection, and non-SLE with infection-the percentages of CD27(high) plasma cells were elevated. The percentage of CD27(high) plasma cells was higher in SLE patients with infection, when compared to SLE patients without infection. CONCLUSION: The percentage of CD27(high) plasma cells is a biomarker for disease activity of SLE without infection, under correlation with SLEDAI, anti-dsDNA, and C3 and C4 level. However, when the SLE patients have an infection, the percentage of CD27(high) plasma cells is not an adequate biomarker for the survey of disease activity. The percentage of CD27(high) plasma cells may serve as a potential parameter to distinguish a lupus flare-up from infection.

Value of the peripheral blood B-cells subsets in patients with ankylosing spondylitis / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The role of B-cell remains an enigma in the pathogenesis of ankylosing spondylitis (AS). This study aimed to investigate the distributions of B-cells and subsets in peripheral blood of AS patients and observe their changes in etanercept-treated AS patents.</p><p><b>METHODS</b>We detected the proportions of CD19(+) B-cell, naive B-cell (CD19(+)CD27-), memory B-cell (CD19(+)CD27dim) and plasmablast (CD19(+)CD27high) in peripheral blood of 66 patients with AS (39 at active stage, 27 at stable stage; 35 patients with peripheral joint involvement, 31 patients with axial involvement alone), 30 patients with rheumatoid arthritis (RA) and 30 healthy volunteers using flow cytometry. And then we observed the changes of the above indexes of 39 active AS patients treated with etanercept in a randomized, double-blind, placebo-controlled trial.</p><p><b>RESULTS</b>(1) Percentages of CD19(+) B-cells in active or peripheral joint involvement AS patients increased more obviously than those in stable or axial involvement alone AS patients (both P = 0.001), and percentage of CD19(+)CD27high B-cells in AS patients with peripheral joint involvement was significantly higher than that in cases with axial involvement alone or healthy volunteers (P = 0.005 and 0.006, respectively); (2) The percentage of CD19(+) B-cells in AS patients was positively correlated with Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) scores, Patient's Global Assessment (PGA) scores, total back pain scores and nocturnal back pain scores (r = 0.270, 0.255, 0.251 and 0.266, P = 0.029, 0.039, 0.042 and 0.031, respectively); (3) At week 6 and week 12, there were no statistical differences of the percentages of B-cells and subsets between etanercept group and placebo group of AS patients (P > 0.05); the percentage of CD19(+) B-cells in etanercept group was higher than that in healthy volunteers at week 12 (t = 3.320, P = 0.003).</p><p><b>CONCLUSIONS</b>Misbalance is present in B-cells and some subsets in peripheral blood of active AS patients with peripheral joint involved. B-cells might play an important role in the pathogenesis of AS patients. The high percentage of CD19(+) B-cells in active AS patients cannot be down-regulated after 12-week etanercept treatment.</p>

Immunophenotypic characterization of the leukemic B-cells from Iranian patients with chronic lymphocytic leukemia: association between CD38 expression and disease progression

Patients with B-cell chronic lymphocytic leukemia [B-CLL] have heterogeneous clinical courses, thus several biological parameters need to be added to the current clinical staging systems to predict disease outcome. Recent immunophenotypic studies performed mainly in Western populations have demonstrated the prognostic value of CD38 and ZAP-70 expression in B-CLL. To investigate the expression pattern of a variety of membrane antigens on leukemic cells from Iranian patients with CLL and to find out if there are any differences in the expression of these markers between indolent and progressive groups. In the present study, peripheral blood samples from 87 Iranian patients with B-CLL were analysed by flow cytometry. In all cases, the neoplastic cells displayed B-CLL phenotype [CD5[+]/CD19[+]/sIg[+]]. The vast majority of the cases expressed CD23, but failed to stain for CD3 or CD14. The leukemic cells of most patients expressed CD27 [84/87, 95.4%] and CD45RO [74/87, 83.9%] molecules, suggesting a memory B-cell phenotype. Comparison between the indolent [n=42] and progressive [n=37] patients revealed significantly higher frequency and intensity of CD38 expression in progressive group [40.5%] compared to indolent [11.9%] patients [p<0.05]. None of the other membrane antigens were differentially expressed in these two groups of patients. Our results obtained in an Asian ethnic population confirm and extend previous findings obtained from Western populations regarding the association of CD38 expression and disease progression in B-CLL

Decreased T cell response to mitogen and increased anti-cytoplasmic antibody in drug-free schizophrenic patients

Apart from genetic and environmental factors, activation of autoreactive mechanisms has been proposed to play a role in the pathogenesis of schizophrenia. In recent years, considerable work has been carried out to understand the role and contribution of the immune system in this disease. To investigate the T cell response to phytohaemagglutinin [PHA] and determine the serum levels of anti-nuclear antibody [ANA], anti-cytoplasmic antibody [ACA], and circulating immune complexes [CIC] in schizophrenic patients. A total of 30 drug-free schizophrenic patients and 42 healthy controls were enrolled in this study. T cell proliferation in response to PHA was measured using Methyl Thiazol Tetrazolium test. ANA and ACA were measured by indirect immunofluorescence. CIC concentration was determined using poly ethylene glycol precipitation assay. Mean PHA response was 1.96 +/- 0.83 in patients and 3.72 +/- 1.39 in healthy controls [p < 0.001]. ANA and CIC concentrations were not significantly different between two groups. In addition, ACA was detected only in patients. Increased production of ACA together with lower T cell response to mitogens in our patients provides evidence for the involvement of autoimmune mechanisms in the pathogenesis of schizophrenia

A Case of Reactive Plasmacytosis Mimicking Multiple Myeloma in A Patient with Primary Sjogren's Syndrome

Primary Sjogren's syndrome (pSS) is a chronic autoimmune disease with welldocumented association of lymphoid malignancies during the progress of the disease. Although several types of malignancy and pseudomalignancy have been reported in pSS, low-grade non-Hodgkin's lymphomas are the most frequently observed. Reactive plasmacytosis mimicking myeloma is a very rare condition in association with pSS. We describe a 72-yr-old woman with pSS who presented with hypergammaglobulinemia, and extensive bone marrow and lymph node plasmacytosis, which mimicked multiple myeloma. In this patient, there was an abnormal differentiation of memory B cells to plasma cells in the peripheral blood suggesting underlying pathogenetic mechanism for this condition.

Study of soluble interleukin-2 receptor in asthmatic children as a marker of t-cell activation in bronchial asthma

The study was designed to determine the degree of activation of T lymphocytes of patients with asthma by measuring the concentration of soluble interleukin-2 receptor in the serum from asthma patients with acute attacks and in remission. We examined 35 asthmatic children in their wheezy state and 35 asthmatic children during remission as well as 30 healthy children matching age and sex. The patients and controls were subjected to full history taking, complete clinical examination, and complete blood picture [including, total leucocytic count, Hb% and absolute eosinophilic count] chest X-ray and serum soluble interleukin-2 receptors. Statistical analysis of the results showed highly significant difference in serum slL-2R from patients with acute asthma than from patients at clinical remission or from control subjects. This study provides further evidence that the more severe the attack the more the concentration of sli-2R. Patients on steroids had lower serum slL-2R than those not received steroids. No correlation between serum concentration of slL-2R and sex, AEC and TLC. There is a negative correlation between serum concentration ofslL-2R and age of asthmatic patients

Soluble adhesion molecules and sCd27 levels in patients with asthma

We examined in serum, soluble adhesion molecules VCAM1, ICAM-1 and E-selectin [SVCAM-1,SICAM-1, [s]E-selectin], soluble interleukin-2 receptor [SCD25] and soluble CD27 [SCD27] in sera of 20 patients with asthma. Measurement of soluble adhesion molecules were analysed by standard ELISA. Soluble CD27 was measured with an ELISA method using CLB-CD27/I and CLB-CD27/II monoclonal antibodies [mAbs]. Levels of serum SCD25 were determined using a commercial standars ELISA [Immunotech] distinct differences between asthma group and normal controls were depicted in the levels of SICAM-1, SE-selectin, SCD27 and SCD25. significantly higher levels of SICAM-1 AND SE- selectin were found in patients with asthma. A correlation between SICAM-1 and SE-selectin was observed in patients with asthma. The increased expression of adhesion molecules in patients with asthma, confirmed an important migration of inflammatory cells to the lung, and that CD27 antigen constitutes a marker of defect in the immunoregulation of asthma

Characterization of cytoplasmic Form of Human CTLA - 4 Molecule / 대한면역학회지

CTLA-4 (=CD152), a T cell activation antigen, has been known to be homologous to CD28 in its molecular and genomic structure. Both of these two molecules are sharing their counterreceptors, B7 (CDSO) and B7-2 (CD86) and are known to play a crucial role in T cell activation. In previous our study it was reported that there are 2 forms of CTLA-4 antigen in activated human T cells, 30 kD membrane-bound form and 34 kD cytosolic-sequestered form and the former was less than 5 % of total of this antigen induced. Aims of this study are to confirm previous finding by using flow cytometry and to characterize the cytoplasmic form of human CTLA-4 by using ultrafiltration and immunoprecipitation techniques. In PHA stimulated peripheral blood lymphocyte surface expression of CTLA-4 was less than 2.1% of any of CD4+, CD8+ and CD56+ subsets. And the 34 kD form of CTLA-4 was detected in CDS+ subset only. This discrepancy confirms that 34 kD antigen is the cytoplasmic form of human CTLA-4. In ultrafiltration and subsequent Western blot analysis study this 34 kD antigen was detected in >100 kD fraction only. And in non-reducing condition this antigen formed high molecular weght complex (MW > 350 kD). In immunoprecipitation study using anti-peptide A antibody it was found that this high molecular weight complex consists of the 34 kD cytoplasmic form of CTLA-4 and previously unknown 54 kD antigen and 46 kD antigen at 1:1:8-10 ratio. And none of these 3 molecules were identified in membrane fraction of activated human T cell. The result of this study implies that CTLA-4 molecule induced upon T cell activation mainly sequestered in cytoplasrn and another signal is necessary to target this antigen on the activated T cell surface.