Monocyte response to LPS after exposure to corticosteroids and chloroquine with implications for systemic lupus erythematosus.

Essential part of a response to infection is early pathogen recognition and adequate initiation of innate immunity. One of the hallmarks of systemic lupus erythematosus (SLE) is reduced resistance to infection despite overall hyperactivity of the immune system. Immunosuppressive drugs (high-dose corticosteroids and cytotoxic agents) are independent risk factors for infection in SLE, with bacteria as predominant cause. To investigate whether less aggressive immunomodulatory treatment may still affect recognition and response to Gram-negative bacteria, we measured TLR4 expression in monocytes of untreated SLE patients and patients on chloroquine and low-dose steroid therapy and examined the drugs' influence on monocyte TLR4 expression in peripheral blood mononuclear cell (PBMC) culture. Additionally, we determined whether induction of monocyte NF-κB signalling, TNF-α and IL-6 production with lipopolysaccharide (LPS), a TLR4 ligand, can be altered with dexamethasone, chloroquine or both. There was no statistically significant difference in TLR4 expression between patients with SLE and controls, even though treated SLE patients tended to have lower frequency of TLR4(+) monocytes and TLR4 mean fluorescence intensity than healthy controls. However, neither dexamethasone nor chloroquine had major influence on TLR4 expression in vitro or suppressed LPS-induced NF-κB activation in monocytes, although dexamethasone decreased TNF-α and IL-6 production. Therefore, even if low-dose steroids or chloroquine do not seem to affect TLR4 expression and signalling, steroids might decrease cytokine production in response to LPS.

Enumeration of haemagglutinin-specific CD8+ T cells after influenza vaccination using MHC class I peptide tetramers.

With emergence of MHC class I tetramers loaded with CD8+ T-cell viral epitopes, it is possible to study virus-specific CD8 cells in humans during infection and after vaccination. MHC class I tetramers was used to detect the frequency of haemagglutinin (HA)-specific T cells in 26 healthy influenza-vaccinated humans. Peripheral blood was collected before, and 7, 14 and 28 days after vaccination. Four-colour flow cytometry was used for monitoring of vaccine induced T-cell response. In 15 donors, two- to fivefold increase in frequency of HA-specific T cells was observed 7 days after vaccination. In addition, in 12 of these donors, this increase was accompanied with fourfold increase of H1N1 antibody titre. The increase in frequency of HA-specific CD8+/IFN-gamma+ cells was low and peaked 28 days after vaccination in three of the six donors tested. Frequencies of HA-specific CD8+ T cells and antibody titre returned to prevaccination values 1 year after vaccination. Subunit influenza vaccines have the ability to induce HA-specific CD8+ cells. As the immune response to this vaccine decreased significantly after 1 year, our results confirm the importance of annual immunization for adequate protection.

Serum cytokine changes after gastric resection or gastrectomy for gastric cancer.

BACKGROUND/AIMS: Although essential for postoperative recovery, excessive surgical stress response leads to higher rate of serious postoperative complications, such as sepsis and multiple organ disorder syndrome. Exact regulation of surgical stress response is not yet known. Still, our ability to modify surgical stress response severity has led to diminished postoperative morbidity and mortality rates and development of fast-track surgery. In this study we tried to further clarify the roles of several cytokines in surgical stress response regulation. METHODOLOGY: We measured leukocyte count and serum concentrations of C-reactive protein, IL-2, IL-6, IL-10, TNF-alpha, IFN-gamma and cortisol in patients undergoing gastrectomy or gastric resection for gastric cancer. Blood samples were collected preoperatively, 3 hours, 24 hours and 48 hours postoperatively. We also grouped our patients according to operation type and duration and then compared measured values between groups. RESULTS: Elevated postoperative leukocyte count and serum concentrations of IL-4, IL-6, IL-10 and cortisol were measured, all peaking at 3 hours postoperatively. Also, serum IL-6 concentration was higher after longer operations, and leukocyte count was higher after gastrectomy. CONCLUSIONS: The synchronicity of postoperative elevation of IL-4, IL-6 and IL-10 concentrations, each having different role in surgical stress response regulation, might indicate that, in order to determine surgical stress response severity, several cytokines should be measured simultaneously.

Phenotypic analysis of receptor-ligand pairs on B-cells in B-chronic lymphocytic leukemia.

Whole-blood three-color immunofluorescence analysis was used to investigate the role of CD5/CD72 and CD21/CD23 receptor-ligand pair formation on B-chronic lymphocytic leukemia (B-CLL) cells as well as sCD23 and bcl-2 oncoprotein expression in disease progression and activity and total tumor mass in B-cell chronic leukemia (B-CLL) patients. Thirty-four patients with B-CLL and 19 controls were included in the study. The majority of B-cells in B-CLL patients coexpressed CD5 and CD72 as well as the CD23 antigen. Unlike B-cells in B-CLL patients, B-cells in all healthy controls tested had high expression of CD21 antigen. We identified two groups of B-CLL patients according to high (n = 20) or low levels (n = 14) of CD21 expression on CD19+CD23+ B-cells. Only in the patients with high CD21 expression, were sCD23 levels positively correlated with factors known to have prognostic significance in B-CLL (Rai stage and TTM) and could, therefore, be used as a prognostic parameter for these B-CLL patients. Bcl-2 oncoprotein expression did not differ between these patient groups. We presumed that in patients with a lower expression of CD21 antigen, the contribution of the CD21 molecule to homotypic adhesion was lacking. Further studies are necessary to determine the possible association of higher expression of the CD21 antigen with disease progression and the aggressive character of the B-CLL.

Cloacal exstrophy: a case report.

A case of an extremely rare type of cloacal exstrophy in a male infant with a normally developed subvesical part of the urinary system and external genitalia but absent distal colon segment is presented. The patient also had omphalocele, upper urinary tract anomalies and sacrococcygeal teratoma.

Cytokine profile of t lymphocytes from peripheral blood and bronchoalveolar lavage fluid in patients with active pulmonary tuberculosis.

The possible immunological relationship between the pattern of Th1/Th2 cytokine production and tuberculin reactivity was assessed in patients with active Mycobacterium tuberculosis infection. The production of the intracellular cytokines interferon (IFN)-gamma and interleukin-4 (IL-4) was measured in CD4(+) and CD8(+) T cells obtained from peripheral blood and bronchoalveolar lavage fluid (BALF) of 20 tuberculin skin-positive patients and compared with the findings recorded in nine tuberculin skin-negative patients with active pulmonary tuberculosis. Upon stimulation with phorbol 12-myristate acetate/ionomycin for 6 h, tuberculin-negative patients had a significantly higher proportion of IFN-gamma-producing CD4(+) T lymphocytes in BALF than in peripheral blood, while both CD4(+) and CD8(+) T-lymphocyte subsets in BALF of tuberculin-positive patients secreted more IFN-gamma than their peripheral blood counterparts. Tuberculin-negative patients had a significantly higher proportion of IFN-gamma-producing CD4(+) T lymphocytes in peripheral blood than tuberculin-positive patients. There was no significant difference in the production of IFN-gamma by BALF CD4(+) T lymphocytes, or by either peripheral blood or BALF CD8(+) T lymphocytes. In two tuberculin-negative patients, peripheral blood CD4(+) T lymphocytes produced IL-4. Study results suggested a higher immune activity in the blood of tuberculin-negative patients, with an increased lymphocyte activity in BALF versus peripheral blood in both patient groups.

Outcome of influenza vaccination in combat-related post-traumatic stress disorder (PTSD) patients.

Post-traumatic stress disorder (PTSD) is an anxiety disorder that can occur after exposure to extreme traumatic experience such as war trauma, and is accompanied by fear, helplessness or horror. Exposure to trauma can result in immune dysregulation and influence susceptibility to infectious disease as well as vaccine efficacy. The aim of the study was to determine the relation of psychological stress and the immune response to influenza vaccination in combat-related PTSD patients (n = 28). Detection of anti-viral antibody titre was performed by inhibition of haemagglutination assay. Ex vivo tetramer staining of CD8(+) T lymphocytes was used to monitor T cells specific for human leucocyte antigen (HLA)-A*0201-restricted influenza A haemagglutinin antigens before and after vaccination. Twenty patients showed a fourfold antibody titre increase to one or both influenza A viral strains, and 18 of them showed the same response for both influenza B viral strains. Ten of 15 healthy controls showed a fourfold rise in antibody titre to both influenza A viral strains and eight of them showed the same response for both influenza B viral strains. HLA-A*0201(+) PTSD patients (n = 10) showed a significant increase of influenza-specific CD8 T cells after vaccination. Although those PTSD patients had a lower number of influenza-specific CD8(+) T cells before vaccination compared to HLA-A*0201(+) healthy controls (n = 6), there was no difference in influenza A antibody titre between PTSD patients and control subjects before vaccination. The generated humoral and cellular immune response in PTSD patients argues against the hypothesis that combat-related PTSD in war veterans might affect protection following influenza vaccination.

Allergen-induced CD23 on CD4+ T lymphocytes and CD21 on B lymphocytes in patients with allergic asthma: evidence and regulation.

Interaction of CD4+ T cells and B cells is necessary for IgE production. It has been recently demonstrated that cell surface antigen CD21 is a ligand for CD23 (Fc epsilon RII) and that the pairing of these molecules may participate in the control of IgE production. In this study we investigated the effect of the Dermatophagoides pteronyssinus (Dpt) allergen and recombinant interleukin(rIL)-4 on the expression of CD21 and CD23 on T and B cells of asthmatic patients allergic to Dpt and of healthy controls. Peripheral blood mononuclear cells (PBMC) were incubated alone or with Dpt allergen (100 biological units/ml) and/or rIL-4 (100 U/ml) for up to 7 days. The flow-cytometric analysis of double-fluorescence staining revealed that Dpt allergen and/or rIL-4 induced CD23 on CD4+ T lymphocytes only in allergic patients. The allergen-induced CD23 on T cells is de novo synthesized antigen since no induction of CD23 on T cells was observed in cultures with 0.4 microgram/ml actinomycin D. Moreover, 100 U/ml of interferon-gamma inhibited the induction of CD23 on CD4+ T cells. T cells obtained from healthy donors did not express CD23 or CD21 antigen upon incubation with allergen and/or rIL-4. Although rIL-4 also induced CD23 in controls, the expression was only observed on CD20+ cells. The allergen alone induced a significant elevation of the mean fluorescence intensity of both CD21 and CD23 only in allergic individuals. When the cell proliferation was analyzed, a slightly increased stimulation index upon cultivation of PBMC was obtained from non-allergic donors as well, but less than in allergic patients. The co-expression of major histocompatibility complex class II molecules and CD23 on CD4+ T lymphocytes in allergic patients, as assessed by the three-color immunofluorescence analysis, indicates that these cells were activated. We conclude that CD4+ T lymphocytes possess a unique capability to express CD23 upon exposure to allergen. Moreover, the allergen-mediated induction of CD23 on T cells observed only in allergic patients may be the reason for the increase of IgE production. This would not occur in non-allergic individuals as there is no CD23 expression on T cells.

The interplay between T helper subset cytokines and IL-12 in directing human B lymphocyte differentiation.

This study asks how T helper (TH) subset cytokines impact upon IL-12-directed change in B cells engaged in signaling via the B cell receptor and CD40, essential components in the initiation of T-dependent B cell responses. For B cells stimulated in this way, IL-12 promoted a distinct phenotype highlighted by the hyper-expression of CD38: the Th1 cytokine IFN-gamma reproduced the IL-12 effects while neutralizing antibody to IFN-gamma reversed IL-12-dependent change. The divergent pathway of differentiation promoted by the Th2 cytokine IL-4 (characterized by hyper-induction of CD23) was left unchecked by IL-12. IL-10 was found to dampen IL-12 actions by suppressing IL-12-dependent IFN-gamma production but failed to perturb the effects of exogenous IFN-gamma. Thus, IL-12--by invoking autocrine IFN-gamma production--promotes phenotypic deviation in B cells engaging T-dependent signals. The reversal of such Th1 driving of B cells by IL-10 only when the source of IFN-gamma is endogenous and the inability of IL-12 to impact upon IL-4-directed differentiation suggest a progressive and hierarchical commitment of B cells to polarization during a developing T-dependent response dominated at the level of the Th cell rather than that of the dendritic cell.

CD21-CD23 ligand pair expression in children with allergic asthma.

The CD23 antigen, a low affinity receptor for IgE, was recently shown to interact with another ligand, CD21, and the pairing of these molecules is important in T cell-B cell interaction and control of IgE production. Here, we analysed the expression of CD21 and CD23 on CD4+ and CD20+ lymphocytes in 25 allergic children and 12 age-matched non-allergic controls. Both the percentage (P < 0.01) and the absolute number (P < 0.001) of CD23+ cells were increased in allergic children. There was no difference of CD21+ cells. Double positive CD4+ CD23+ cells (2.5%) were only detected in one patient, in others all CD23 being expressed on B cells. The CD21 antigen was expressed only on B cells. Furthermore, allergic children had an increased mean fluorescence intensity of both the CD21 (P < 0.001) and the CD23 (P < 0.001) receptor. To analyse the possible difference in B cell subsets expressing CD21 and CD23 antigens, three-colour fluorescence analysis was performed. In allergic children the subset of CD20+ CD21- cells expressed more CD23 than in controls (P < 0.001). These results may mean an impaired expression and possibly regulation of CD21-CD23 interaction in allergic conditions.

Congenital pulmonary arteriovenous fistula: a rare cause of cyanosis in childhood.

Two children (both females) aged 15 months and 4 years are described as very rare cases of central cyanosis in childhood being caused by a congenital pulmonary arteriovenous fistula. The initial diagnosis was made based on cyanosis and chest radiographs, with normal physical, ECG, and radiological findings of the heart. They had no family history of the Rendu-Weber-Osler syndrome. The patients underwent cardiac catheterization and pulmonary angiography, where the diagnosis was confirmed. After the surgery, both were symptom-free, and had no evidence of the disease.

Effect of an asthmatic attack on CD23 and CD21 expression on lymphocytes from allergic children during the allergen season.

BACKGROUND: The overproduction of IgE antibodies by atopic individuals in response to inhaled aeroallergen, forms the basis of an allergic disease. Furthermore, the exposure to allergen might trigger the symptom exacerbation. OBJECTIVE: In children with bronchial asthma, the possible effects of seasonal, natural exposure to allergen on the expression of CD21 and CD23 antigens on B lymphocytes, and on the expression of HLA-DR, CD45RA and CD45RO on CD4+ T cells investigated. METHODS: Heparinized blood samples were obtained from 15 children with bronchial asthma allergic to Dermatophagoides pteronyssinus (Der p) at the time of an acute asthmatic attack and 2-4 weeks after the attack when the peak expiratory flow (PEF) was stabilized. The samples were analysed on a flow cytometer after the three-colour immunofluorescence staining had been performed. RESULTS: The increased proportion of B cells expressing CD23 antigen was found at the time of attack rather than after stabilization. Serum levels of total and Der p-specific IgE increased 2-4 weeks after the asthmatic attack. This increase was accompanied by a further increase in the expression of CD23 antigen on CD21- B lymphocytes. In 10 out of 15 tested children, we found CD23 expressed on CD4+HLA-DR+ T cells during the asthmatic attack. No significant difference was found in the expression of CD45RA and CD45RO. CONCLUSION: Since we have previously demonstrated the increased percentage of CD23 on CD21- B cells in allergic children as compared with controls, we speculate that natural exposure to the allergen which caused the increase in total and specific IgE levels might be related to the increased expression of CD23 on CD21- B cells.

Effect of cysteinyl leukotriene receptor antagonist on CD11b and CD23 expression in asthmatic children.

BACKGROUND: Cysteinyl leukotrienes are potent pro-inflammatory mediators that contribute to the pathophysiologic features observed in allergic asthma. Inhibitors of leukotriene receptors represent novel therapy in asthma treatment. In addition to the protection from early asthmatic responses, these drugs have recently been shown to protect from late airway responses too. METHODS: We studied the effect of treatment with an oral antagonist of cysteinyl leukotriene receptors on the increased expression of the low-affinity IgE receptor, CD23, on B cells, and of its ligands, CD11b and CD11c, on CD4(+) T cells and monocytes in peripheral blood of patients with allergic asthma. In this uncontrolled open-label study, 14 children with allergic asthma received montelukast, a cysteinyl leukotrine receptor antagonist, for a period of 6 weeks after demonstrating forced expiratory volume in 1 s (FEV(1)) of less than 80% of the predicted value. Samples of peripheral heparinized blood and sera were obtained before and after therapy completion. Three-colour immunofluorescence analysis was performed, and expression of CD11b and CD11c on CD4(+) T lymphocytes and monocytes as well as the expression of CD21 and CD23 on B cells were determined (n=12). Peripheral blood eosinophil count, changes in FEV(1) and peak expiratory flow rate (PEFR), asthma exacerbations, and as-needed use of beta-agonist were also monitored. RESULTS: Montelukast improved FEV(1) and PEFR, and decreased peripheral eosinophil counts in all study patients. There was no significant change in the expression of CD21 and CD23 on B cells. The expression of CD11c on CD4(+) T cells and of both CD11b and CD11c on monocytes remained similar to the pretreatment expression. However, the percentage of CD11b(+)CD4(+) T lymphocytes significantly decreased after treatment with montelukast. This was accompanied by a significant decrease in the levels of total IgE. CONCLUSION: The capacity of 6-week montelukast therapy to reduce the percentage of CD11b CD4(+) T cells might be a mechanism leading to the immune response modulation on this T cell subset interaction with CD23-expressing B cells and subsequent down-regulation of IgE synthesis.

Expression of CD23 antigen and its ligands in children with intrinsic and extrinsic asthma.

The role of the low-affinity IgE receptor CD23 in immune reactions has been further emphasized by recent discoveries of novel surface ligands for CD23: CD21, CD11b, and CD11c. We previously observed the difference between the expression of CD23 and CD21 antigens in children suffering from extrinsic asthma when compared to healthy controls. In the present study, we investigated the expression of CD23 and its ligand CD21 on CD20 B cells in 44 asthmatic children (23 allergic and 21 nonallergic) using three-color immunofluorescence analysis. In addition, the expression of two other ligands for CD23, CD11b, and CD11c, on T cells (CD3+), a subpopulation of T cells (CD4+ and CD8+), natural killer cells (CD56+), and monocytes (CD14+) was tested by two-color immunofluorescence analysis in 12 allergic and 14 nonallergic children. We found that children with extrinsic asthma had higher levels of CD23+ B cells than those with intrinsic asthma. No difference was observed in the percentage of either CD23+CD21+ or CD23-CD21+ B cells. The CD11b antigen was expressed on each tested population, but only on CD4+ T cells was CD11b significantly increased in children with extrinsic asthma. CD11c was expressed mainly on monocytes, and no difference was observed between tested groups. The increased percentage of CD11b antigen on CD4+ T cells and the increased percentage of CD23 antigen on B cells in children with extrinsic asthma provide further evidence of the immunologic differences between intrinsic and extrinsic asthma.

Decision-tree approach to the immunophenotype-based prognosis of the B-cell chronic lymphocytic leukemia.

Use of a nonlinear prediction method, such as machine learning, is a valuable choice in predicting progression rate of disease when applied to the highly variable and correlated biological data such as those in patients with chronic lymphocytic leukemia (CLL). In this work, decision-tree approach to cell phenotype-based prognosis of CLL was adopted. The panel of 33 (32 different phenotypic features and serum concentration of sCD23) parameters was simultaneously presented to the C4.5 decision tree which extracted the most informative of them and subsequently performed classification of CLL patients against the modified Rai staging system. It has been shown that substantial correlation between the percentage of expression of the CD23 molecule on CD19+ B-cells, the level of sCD23, the percentage of CD45RA+, and the absolute number of CD4CD45RA+RO+ T-cells and the clinical stages, exists. The prediction vector, composed of their concatenated values, was able to correctly associate 83% of the cases in the low-risk group (Rai stage 0), 100% of the cases in the intermediate-risk group (Rai stage I and II), and 89% of the cases in the high-risk group (Rai stage III and IV) of CLL patients. Predictivity of this vector was 100%, 95%, and 89%, respectively. In conclusion, from the described analysis, it may be inferred that two processes play important roles in the progression rate of CLL: 1.deregulated function of the CD23 gene in B-cells accompanied by the appearance of its cleaved product sCD23 in the sera; and 2. functionally impaired and imbalanced CD4 T-cell subpopulations found in the peripheral blood of CLL patients.

Expression of lymphocytes Fc epsilon RII/CD23 in allergic children undergoing hyposensitization.

Owing to the proposed role of Fc epsilon RII/CD23 in allergic diseases, we analyzed the expression of this receptor on peripheral blood lymphocytes (pan-B, pan-T and CD4+ or CD8+ T cells) and its autoproteolytic product sCD23 in serum. This was done in 10 asthmatic children allergic to Dermatophagoides pteronyssinus (Dpt) before and 6 weeks after hyposensitization. FACS analysis of double, direct immunofluorescence staining of the whole blood revealed an elevated percentage of Fc epsilon RII/CD23+ lymphocytes in allergic children (10.29 +/- 5.0), a significantly higher percentage than in nonallergic children (5.7 +/- 2.4, p < 0.05). The majority of Fc epsilon RII/CD23+ were on B cells. A significant positive correlation between the percentages of CD23+ lymphocytes and serum IgE levels was found (Spearman rank = 0.63, p < 0.05). The percentage of CD20+CD23+ lymphocytes significantly decreased after 6 weeks of hyposensitization (6.2 +/- 3.6, p < 0.05), while the percentage of CD20+ lymphocytes remained unchanged. Similarly, hyposensitization was followed by a reduction of total serum IgE levels, but Dpt-specific IgG4 and IgE remained unchanged.

Prolegomenon for chronic lymphocytic leukaemia.

Chronic lymphocytic leukaemia (CLL) is a unique lymphoproliferative disorder that scarcely occurs under the age of 40; thereafter the incidence of CLL increases exponentially with age. CLL is characterized by progressive expansion of malignant CD5+ME+ B-cell clone accompanied by a myriad of cellular and humoral immune defects. Each of them might be linked to different clinically manifested complications such as increasing rate of infections, autoimmune disorders and disturbed immune surveillance against tumour cells. We assume that CLL occurs as a consequence of age-dependent, genetically related functional restrictions of the thymic microenvironment in supporting common lymphoid progenitor cells (CD5+ME+CD4-CD8-) to differentiate into mature T-cell and B-cell descendants. In conjunction with genetic abnormalities developing in B-cell progenitors, presumably expressing P glycoprotein (Pgp+), we postulate that developmentally altered T-cell descendants, along with quantitative imbalance among CD4+, their subsets and CD8+ lymphocytes in the peripheral blood, play an important additional role in facilitating the malignant B-cell clone emergence and in modulating the CLL clinical evolution. Namely, imbalance of any of T-cell-mediated cell interactive homeostatic mechanisms accompanied by imbalance in the production of various cytokines might in CLL influence leukaemic B-cell growth by deregulating inducer (c-myc and p53) and/or suppressor (bcl-2 and mutant p53) oncogenes responsible for the promotion or suppression of B-cell mitogenesis that may in turn further contribute to their impaired differentiation and/or differentiation arrest. In conclusion, CLL might be interpreted as a primary immunodeficiency syndrome developing in elderly population due to gradually evolving restriction of genetically controlled programs in the thymic microenvironment responsible for irregular maturation of common lymphoid progenitor cells that constitutively express CD5 antigen and ME receptor into T-cell and B-cell descendants.

CD5-positive and CD5-negative human B cells converge to an indistinguishable population on signalling through B-cell receptors and CD40.

Whether CD5 on B cells marks a subset functionally distinct from the conventional CD5 negative (CD5neg) adult population or is more an indicator of activation, remains contentious. Here we have investigated whether CD5 positive (CD5pos) and CD5neg B cells can be distinguished in terms of their response to surrogate signals aimed to model, in vitro, T-cell dependent (TD) and T-independent (TI) encounters with antigen in vivo: the predominantly CD5pos B-cell population found in cord blood, CD5 B cells positively selected from tonsils and their CD5neg counterparts, were compared. Neonatal B cells displayed a near-identical phenotype to that of adult CD5pos B cells, being characterized by uniform immunoglobulin M (IgM), immunoglobulin D (IgD), CD23 and CD44 coexpression. When cultured with anti-IgM maintained at high density on CD32-tranfected mouse L cells to model TI responses or on CD40 ligand (CD40L)-bearing L cells (with or without captured anti-IgM) to model TD encounters, DNA synthesis was stimulated to a similar extent in all three populations. Focusing on CD5 and CD23, we found that - although the signals delivered promoted distinct profiles of expression - under each condition of activation, the phenotypes that emerged for adult CD5pos and CD5neg B cells were remarkably similar. Neonatal B cells displayed a greater diminution in CD5 expression than adult CD5pos B cells following CD40 signals but otherwise the two populations again behaved similarly. The inclusion of interleukin-4 (IL-4) to cultures where cells were costimulated via surface (s)IgM and CD40 resulted in a complete loss of CD5 expression and a corresponding hyperexpression of CD23, irrespective of the population studied. The near-identical response of CD5pos and CD5neg B cells to surrogate TD or TI signals in vitro and their convergence to indistinguishable phenotypes is wholly supportive of CD5 being a fluctuating marker of activation rather than it delineating functionally distinct subsets.

Decrease in CD23+ B lymphocytes and clinical outcome in asthmatic patients receiving specific rush immunotherapy.

Rush immunotherapy (RIT) has been documented as useful in the treatment of patients with allergic bronchial asthma. To investigate the mechanisms of its action, we studied changes in the serum levels of total IgE, allergen-specific IgE and IgG4, and expression of CD23 on peripheral blood B cells in patients receiving RIT. Twenty patients with perennial bronchial asthma were evaluated before the beginning of RIT, as well as 6 weeks and 6 months later. Compared to pretreatment values, the level of Der-p-specific IgG4 and IgE significantly increased after 6 weeks and 6 months of RIT, while the total serum IgE remained unchanged. Furthermore, after 6 months of RIT, the percentage of CD23+B cells and its CD23 receptor density significantly decreased. Since the symptom score improved and the need for medication decreased, we evaluated RIT as a useful procedure. After 6 months, 30% of patients did not have an asthma attack, with no medication in the last month, while 10% of them were asthma free for the last 3 months. No significant correlation between the clinical improvement, and in vitro changes was found. Furthermore, the observed in vitro changes were not significantly different in patients who responded with clinical improvement, compared to those with unchanged intensity of asthma. In conclusion, during specific RIT we found a significant increase in Der-p-specific IgE and IgG4 antibodies, as well as a moderate decrease in CD23+ B cells and its CD23 receptor density. These findings suggest a change in the lymphokine profile of patients receiving specific immunotherapy, and that the inhibition of IL-4-induced B cell stimulation may be hypothesized as the most important mechanism.