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Biomedical subjects

A Gagro

Publications and source records attributed to A Gagro.

13 recordsLinked to original sources
PubMed1999

Role of peripheral blood mononuclear cell (PBMC) phenotype changes in the pathogenesis of haemorrhagic fever with renal syndrome (HFRS).

Hantaviruses cause an important human illness, HFRS. Blood samples from 22 HFRS-positive, six seronegative patients and 15 healthy controls were examined in 1995, during the largest HFRS epidemic in Croatia. Results of double- and triple-colour immunofluorescence analysis showed an increased percentage of cytotoxic T cells (CD3+CD8+) in seropositive patients compared with seronegatives and healthy controls. The majority of seropositive HFRS patients expressed activation and memory antigens on T and B lymphocytes. The percentage of CD23+ and CD21+ B lymphocytes was lower in seropositive patients. HFRS patients had elevated levels of sCD23 and five had elevated total IgE. The increased expression of both early and late T cell activation antigens, e.g. CD25, CD71 and HLA-DR, memory cells and sCD23 positively correlated with biochemical parameters (AST, ALT, urea, alpha2-globulin) during the acute phase of HFRS. The phenotypic changes observed, especially early and late T cell activation markers, as well as memory cells, could be useful parameters in the evaluation of HFRS course, and prognostic factors of HFRS severity. Additional attention should be paid to liver involvement in the pathogenesis of HFRS.

Adult↗
PubMed1998

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.

Aged↗
PubMed1997

Increase in CD23+ B cells in infants with bronchiolitis is accompanied by appearance of IgE and IgG4 antibodies specific for respiratory syncytial virus.

Infection with respiratory syncytial virus (RSV) may induce asthma-like symptoms and RSV-specific IgE in infected infants as a result of Th2-like response to RSV. The effect of RSV infection on the expression of B cell antigens CD21 and CD23, putative participants in Th2 responses, was investigated. Samples from bronchiolitic infants (n = 19) were tested by three-color immunofluorescence flow cytometry during the acute phase of infection and 4-6 weeks later. In 6 of 10 RSV-positive infants, the percentage of CD23+ B cells was higher than in 9 RSV-negative children and in controls. Both CD21+ and CD21- B cells exhibited a higher percentage of CD23. The group with increased expression of CD23 antigen had RSV-specific IgE and IgG4 antibodies. These findings corroborate the hypothesis that RSV could provoke a Th2-type response, but the relationship between CD23 antigen and RSV infection must be determined.

Antibodies, Viral↗
PubMed1997

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.

Adolescent↗
PubMed1997

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.

Aged↗
PubMed1996

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.

Adolescent↗
PubMed1995

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.

Adolescent↗
PubMed1994

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.

Adult↗
PubMed1993

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.

Adolescent↗
PubMed1993

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.

Allergens↗
PubMed1991

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.

Arteriovenous Fistula↗
PubMed1991

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.

Abnormalities, Multiple↗