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Biomedical subjects

E Buendia

Publications and source records attributed to E Buendia.

At least 19 recordsLinked to original sources
PubMed2001

Lymphocyte populations in Parkinson's disease and in rat models of parkinsonism.

To assess the involvement of the immune system in Parkinson's disease we studied the phenotype of circulating lymphocytes in 30 untreated and 34 treated patients. We found a numeric decrease in helper T cells (higher in CD4(+)CD45RA(+) than in CD4(+)CD29(+)) and B cells, and a rise in activated, CD4(+)CD25(+) lymphocytes that was correlated with lymphocyte depletion. All these alterations were independent of levodopa treatment. In addition, we performed striatal dopamine depletion in rats with either MPP(+) or 6-OHDA, showing that MPP(+) but not 6-OHDA can increase CD4(+)CD25(+) lymphocytes. Thus, mechanisms other than dopamine deficit may explain the immune activation in Parkinson's disease.

Aged↗
PubMed2000

Predictors of atopy in HIV-infected patients.

BACKGROUND: Some studies have reported an increase of atopy in HIV-infected (HIV+) patients, but the cause still remains unclear. OBJECTIVE: To determine the prevalence of atopy in HIV+ patients and to investigate its predictors. METHODS: Seventy-four HIV+ hospitalized patients (46 of them with AIDS) were studied prospectively for the presence of atopy, based on immediate hypersensitivity to common allergens by prick test. Serum immunoglobulins, specific IgE, lymphocyte subsets, and the expression of low affinity IgE receptor (CD23) on B cells were determined. RESULTS: Thirty-one percent of patients presented IgE values greater than 150 ku/L (39% of patients without AIDS and 26% of AIDS patients; P = .23) and 47% showed an increase (> or = 2%) in the percentage of CD23+ B cells. Non-AIDS patients had higher IgE values than AIDS patients (346 +/- 605 versus 175 +/- 276; P = .16). Atopy prevalence was higher in non-AIDS than in AIDS patients (28% versus 11%; P = .06). Specific IgE agreed with positive prick test in 58% of cases. Multivariate analysis showed that a personal history suggestive of allergic disease and IgE > 150 ku/L were predictors of atopy, while gender, risk group, CD4+ T cells, CD23 expression on B cells, and AIDS were not associated. CONCLUSIONS: HIV+ patients present a higher prevalence of atopy in early stages of HIV infection than general population. Since allergic reactions could accelerate HIV-infection by increasing type 2 cytokines, it is important to evaluate the atopic state in HIV+ patients with IgE > 150 ku/L or with suggestive allergic history in order to prevent it.

Adult↗
PubMed1998

Peripheral blood lymphoid subsets and long-term clinical course of kidney recipients: a longitudinal study.

A longitudinal study of peripheral blood lymphocyte subsets was performed in 23 renal allograft recipients treated with prophylactic antilymphocyte antibodies, CsA, and steroids. At day 0 samples were obtained before transplantation (Tx), and afterwards at months +1, +3, +6, +9, +12, +24, +36, and +48. In all patients, after the depletion of lymphoid subsets during antilymphocyte antibody treatment, CD8+ lymphocytes recovered and reached higher values than those observed prior to Tx. This was mainly due to an increase in CD8+CD45RA+ lymphocytes; in contrast, the levels of "memory" CD4+ T cells and the CD4+CD62L+ subset remained low during all the follow-up period. In patients with preserved graft function (n=14) (with creatinine levels below 200 micromol/mL), the initial, relative decrease in CD4+ T cells was never reversed and the recovery of CD8+ lymphocytes started early. They also presented a peak of HLA-DR antigen expression at 1 month, not observed in those patients displaying a suboptimal graft function. At 1 month, the patients with suboptimal graft function (n=9) (with creatinine levels above 200 micromol/mL) showed higher number of CD4+ T cells, delayed recovery of CD8+ lymphocytes, and higher percentage of activated lymphocytes from month +3 on than well-functioning kidney recipients. Both CD8+ lymphocytes and HLA-DR+ T cells, found at month + 1 post-Tx, were negatively correlated with the concentration of creatinine along the follow-up. Interestingly, the mean percentage of CD4+CD25+ T cells found 36 and 48 months after Tx were positively correlated with creatinine concentration at these times. These findings indicate that variations in the distribution of lymphocyte subsets are related with a long-term graft outcome. Within the first month after Tx, a rapid recovery of CD8+ lymphocytes, but not of CD4+ T cells, and a peak of HLA-DR expression, are associated with a good graft function. In contrast, long-term expression of activation markers is related with renal dysfunction.

Adult↗
PubMed1998

Distinct modulation by interferon-gamma (IFN-gamma) of CD23 expression on B and T lymphocytes of atopic subjects.

The low-affinity IgE receptor (FcepsilonRII/CD23) plays a role in IgE production. Cytokines participating in IgE synthesis also modulate CD23 expression on lymphocytes, but whether this modulation is different in atopic subjects remains unclear. We studied CD23 expression on B and T lymphocytes in 10 asthmatic patients with Dermatophagoides pteronyssinus hypersensitivity and 10 healthy non-atopic subjects. Studies were performed by flow cytometry, in phytohaemagglutinin (PHA) or IL-4-stimulated mononuclear cell cultures, alone or in the presence of IFN-gamma. Soluble CD23 (sCD23) released in the culture supernatants was measured by enzyme-linked immunoassay. Both PHA and IL-4 induced the expression of CD23 on lymphocytes of atopic and non-atopic subjects. Whereas PHA increased both the percentage and mean fluorescence intensity of CD23+ B and T cells, IL-4 alone did not increase the percentage of CD23+ T cells. The effects of IFN-gamma were different in both groups, since it was able to reduce the percentage of PHA-stimulated CD23+ T cells only in non-atopic individuals. In non-atopic subjects more than atopic, levels of sCD23 were increased in the supernatants of PHA and IL-4 cultures. These results show that the modulation of CD23 expression is different on B and T cells, and that IFN-gamma acts differently in atopic and non-atopic individuals.

Allergens↗
PubMed1996

Longitudinal study of the frequency of cytotoxic T cell precursors in kidney allograft recipients.

Clonal deletion or inactivation of donor-specific alloreactive cells are important mechanisms that are believed to account for acquired immune tolerance in allograft recipients. Serial assessment of precursor cytotoxic T lymphocyte frequencies (CTLpf) by limiting dilution analysis (LDA) provides information at the clonal level on changes in the alloimmune response of graft recipients. We performed a longitudinal study of 15 cadaveric kidney recipients before and every 3 months throughout the first year after transplantation (Tx). Pre-Tx values of donor CTLpf showed high interindividual variability without a predictive value for the clinical outcome. All patients with well functioning kidneys had decreased CDLpf at 3 months post-Tx in comparison with pre-Tx values. This decrease was donor-specific in four patients and was permanent in two cases throughout the study. Most patients presented decreased anti-donor CTLpf values from 6 to 9 months, whereas a partial recovery of donor CTLpf was observed in three patients. Reversible acute rejection was diagnosed in three patients, and it was associated with a marked increase in anti-donor CTLpf, returning to pre-Tx values by 9 months post-Tx. In addition, one patient with chronic rejection displayed a transient increase in CDLpf 6 months after Tx. The results of this sequential study indicate the establishment of a state of either hyporesponsiveness or functional clonal inactivation, transient or permanent, which could facilitate allograft acceptance.

Adult↗
PubMed1996

Ebastine in context. Introduction.

The allergic reaction to a specific antigen is characterised by a series of complex immunological processes consisting of an early specific immune response and a late inflammatory reaction. The release of active substances (principally histamine) from cytoplasmic granules of mast cells and basophils in response to antigen challenge is responsible for many of the symptoms observed in the early phase of the allergic reaction. The late phase inflammatory reaction caused by the recruitment of inflammatory cells (mainly eosinophils) to the area of initial antigen challenge and the consequent release of soluble factors result in amplification and prolongation of allergic symptoms. Antihistamines are the most widely used drugs for the treatment of allergic conditions. These agents act on both the early immune response (by blocking the action of histamine at the H1 receptor) and also demonstrate anti-inflammatory effects. Second generation antihistamines are free of the sedative and anticholinergic effects characteristic of the first generation agents. Ebastine, the focus of this supplement, is a new second generation agent that has shown antihistamine activity in preclinical studies and clinical efficacy in providing relief from symptoms in patients with allergic disorders.

Histamine Antagonists↗
PubMed1995

T cell subsets in multiple sclerosis: a serial study.

The relevance of abnormalities in the distribution of peripheral blood T lymphocyte subsets to the clinical manifestations of multiple sclerosis is not firmly established. A clinical and immunological follow-up of relapsing-remitting multiple sclerosis patients was performed in order to study the relationship of immune changes with the clinical course of the disease. Twenty patients were monitored monthly during a mean time of nine months for peripheral blood lymphocyte subsets (CD3, CD4, CD8, CD19), including the immunoregulatory subsets CD4CD29 (helper-inducer), and CD4CD25) by flow cytometry. A total of 14 untreated relapses was included. The most significant observations were a decrease in T suppressor-inducer CD4+ CD45RA+ subset during clinical relapses (P = 0.028) that was also detectable one month before (P = 0.020) and the lack of changes in CD4+ CD29+ and CD8+ T cells. In addition, variations in the percentage of CD4+ CD25+ activated T helper cells were not associated with clinical exacerbations. These results indicate the existence of a temporal association of immune changes in peripheral blood, but not activation, with the clinical manifestations of multiple sclerosis.

Adolescent↗
PubMed1993

CD23 expression on B-lymphocytes and its modulation by cytokines in allergic patients.

The aim of this study was to assess the expression of CD23 on peripheral blood B-cells, and its in vitro modulation by recombinant human interferon-gamma (IFN-gamma) in phytohaemagglutinin-(PHA) or recombinant human interleukin-4 (IL-4)-stimulated cultures in atopic patients with Dermatophagoides pteronyssinus hypersensitivity and in healthy non-atopic subjects. Atopic patients with asthma not receiving allergen-specific immunotherapy (n = 21) were studied and further compared with a group of atopic subjects with asthma under allergen-specific immunotherapy (n = 21). They were age-(+/- 5 yr) and sex-matched. The results were also compared with those obtained in the non-atopic group (n = 11). CD23 expression on B-lymphocytes and its modulation were analyzed by flow cytometry using conjugated monoclonal antibodies with a double immunofluorescence method. Atopic patients had an increase in the percentage of B-cells expressing CD23 in peripheral blood. Phytohaemagglutinin and IL-4 induced a rise in the percentage of CD23-positive B-cells in both atopic groups and non-atopic subjects. Phytohaemagglutinin provoked an increase in the intensity of CD23 expression on B-cells from stimulated cultures in all groups, while IL-4 only produced a significant increase in atopic patients. The presence of IFN-gamma decreased the CD23 expression on B-cells in PHA-stimulated culture of atopic patients, whereas it caused an increase in CD23 expression in the non-atopic group. Furthermore, the presence of IFN-gamma in IL-4-stimulated cultures induced a decrease in CD23 expression on B-cells in all cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

IgE antibodies against bovine serum albumin in a case of eosinophilic gastroenteritis.

Eosinophilic gastroenteritis is a disease characterized histologically by an eosinophilic infiltration of the gut. The cause of this disease remains unclear, although both food allergy and food intolerance have been implicated in its pathogenesis. We report the case of a 22-year-old man in whom gastrointestinal symptoms first appeared in childhood, with involvement of mucosa and muscularis layers of stomach and bowel. He presented high IgE blood levels, and his prick test was positive to bovine, pig, and lamb sera. Immunoblots from calf, pig, and lamb sera, incubated with the patient's serum and revealed by autoradiography, demonstrated the presence of a 65-kDa protein band that was recognized by IgE antibodies but not by IgG. This band corresponded to bovine serum albumin, while IgE did not show reactivity with human albumin. These data suggest a possible role for IgE-mediated hypersensitivity mechanisms in the pathogenesis of eosinophilic gastroenteritis.

Adult↗
PubMed1992

Lymphocyte immunophenotyping by flow cytometry in normal adults. Comparison of fresh whole blood lysis technique, Ficoll-Paque separation and cryopreservation.

In the present report we have assessed the extent to which Ficoll-Paque separation and cryopreservation of mononuclear cells alter the measurement of lymphocyte subsets by flow cytometry. Standard Ficoll-Paque separation increased the percentage of CD4+, CD19+ and CD4+CD45RA+ cells, as well as decreasing that of CD8+, and CD4+CD29+ cells, compared to the fresh whole blood lysis technique. Moreover, cryopreservation caused a depletion of CD4+ p80+ cells, but normal whole blood values were restored following a short incubation.

Adult↗
PubMed1991

Blood lymphocytes are sensitized to branchial plexus nerves in patients with neuralgic amyotrophy.

The percentage of lymphocytic subsets in the blood of cases with neuralgic amyotrophy (NA), and the proliferative response of blood lymphocytes cultured with different nerve extracts, obtained from normal subjects at postmortem, were examined in 6 patients with NA and in 18 age-matched controls with shoulder pain not related to NA. Most (5/6) NA patients had decreased CD3 values and increased CD4/CD8 ratios due to a decreased of the CD8 subset. Lymphocytes of NA patients increased their blastogenic activity in cultures with nerve extracts from different brachial plexus nerves and its branches, but not in cultures with extracts of sacral plexus nerves. Cultures did not respond to nerve extracts in any of the control cases, although mitogenic activity was similarly elicited in cultured lymphocytes stimulated with phytohemagglutinin in both control cases and NA patients. These results suggest that NA is probably an immune mediated disease.

Adolescent↗