Correlation of lymphocyte proliferating cell nuclear antigen expression with dietary cow's milk antigen load in infants with allergy to cow's milk.

BACKGROUND: Controversial results have been reported on the participation and diagnostic value of lymphocyte reactivity in cow's milk (CM) allergy. In this study, we used a specific nuclear marker to evaluate lymphocyte proliferation in IgE-mediated CM allergy in infants, and examine its relation with diets containing different CM antigen loads. METHODS: Infants with IgE-mediated CM allergy, as assessed by open provocation and RAST, were grouped according to their exclusive diet, either CM formulae, breast feeding, or hydrolysed whey formulae. A group of non-atopic infants receiving CM was also examined. Lymphocyte proliferation to beta-lactoglobulin was evaluated by quantitation of the proliferating cell nuclear antigen (PCNA) expression in peripheral blood mononuclear cells, by flow cytometry. Immunophenotypic surface markers were also examined. RESULTS: A marked difference of PCNA expression between CM-fed allergic infants and healthy controls was observed (p<0.001). In this setting, PCNA expression >/=10% was highly specific and sensitive as a marker of CM allergy in CM-fed infants. Moreover, a significant correlation (p<0.001) between antigen load and PCNA was established in CM-allergic infants under different diets, higher values obtained with increasing antigen loads. In addition, within the group fed hydrolyzed formulae, low-molecular-weight products resulted in marginally lower PCNA expression than higher-molecular-weight formulae. No differences in immunophenotype were found, with the exception of a higher CD23 expression in the breast-fed group. CONCLUSIONS: PCNA could be a useful marker in the assessment of lymphocyte proliferation to CM antigens. Low CM antigen diets are related with reduced lymphocyte reactivity, which may partly explain the clinical benefit observed with such diets.

Prognostic significance of autoantibodies against tropomyosin in patients with colorectal adenocarcinoma.

We examined, with an enzyme-linked immunoadsorbent assay (ELISA) method, the serum of 55 patients with Colon Adenocarcinoma (CA) for the presence of autoantibodies against tropomyosin (TMS), of IgM and IgG isotypes, before and 1 month after surgery. Twenty-six (26) patients with benign surgical diseases (BSD) (hernia or cholelithiasis) and 40 healthy volunteers were used as controls. Preoperatively, 20/55 (36.3%) of CA patients and 2/26 (7.7%) of BSD patients were positive for anti-TMS antibodies, while postoperatively, the positive samples were 22/55 (40%) and 2/26 (7.7%), respectively. The difference between the group of CA patients and the two control groups was statistically significant (p < 0.001). The presence of anti-TMS antibodies has been associated with better outcome of CA patients: 30 CA patients (30/55, 54.5%) had detectable anti-TMS antibodies either preoperatively or postoperatively and 25 CA patients (25/55, 45%) were completely negative in both occasions. In the first group of patients, four (4) recurrences were detected (4/30, 13.3%) while in the second group nine (9) recurrences were found (9/25, 36%). The difference between the two groups was statistically significant (p < 0.01). Anti-tropomyosin antibodies could be used as biological markers of prognosis in colon cancer patients.

Interferon-gamma pretreatment of peripheral blood mononuclear cells partially restores defective cytokine production in children with atopic dermatitis.

Interferon-gamma (IFN-gamma) is considered an important determinant of the balance between T-helper type 1 and 2 cytokines and has been used experimentally for the treatment of atopic dermatitis. However, contrasting results have been reported relative to the Th-1/Th-2 cytokine profile in atopic patients. In this study, we examined cytokine production by polyclonally activated peripheral blood mononuclear cells (PBMC) from children with atopic dermatitis, and assessed the influence of in vitro IFN-gamma pretreatment on these cells. A fraction of PBMC isolated from children with severe atopic dermatitis, as well as from age-matched controls, was initially exposed to IFN-gamma. After washing, both treated and untreated cells were then put into culture either alone or with the addition of phytohemagglutinin (PHA) or phorbol myristate acetate (PMA) plus ionomycin. IL-4, IL-5, IL-10 and IFN-gamma production were measured in the supernatants using commercially available ELISAs. PBMC from atopic patients produced more IL-4 (P = 0.04) and IL-10 (P = 0.03) and less IFN-gamma (P = 0.01) than controls, when stimulated with PHA. Interestingly, in PMA + ionomycin stimulated cultures, the atopic cytokine profile was different with more IL-5 (P = 0.0068) and less IFN-gamma production (P = 0.00046) than the control group. When cells were pretreated with IFN-gamma, there were no significant differences between patients and controls. PBMC from children with atopic dermatitis show alterations in cytokine production, compatible in general terms with the Th-1/Th-2 model. Exposure of PBMC to IFN-gamma before activation results in a reduction of these differences, so that cytokine production becomes similar in the atopic and normal groups.

Abnormal expression of p120 correlates with poor survival in patients with bladder cancer.

p120 is a cytoplasmic molecule closely associated with the Ca(2+)-dependent cell-cell adhesion molecule E-cadherin, by forming complexes between the cytoplasmic domain of E-cadherin and the cytoskeleton. Although it has been shown that loss or downregulation of E-cadherin is associated with an invasive and poorly differentiated phenotype in several tumours, there is very little information available concerning p120 expression in malignant disease. We used an avidin-biotin immunoperoxidase technique to examine the immunoreactivity and cellular localisation of p120 and E-cadherin in 68 transitional cell carcinomas (TCC) and 14 normal bladder biopsies and correlated these results with pathological and clinical parameters. E-cadherin and p120 were expressed in a normal membranous pattern in all normal bladder epithelium specimens. Loss of normal surface E-cadherin and p120 expression was found in 52/68 (76%) and 57/68 (84%) tumours, respectively. There was a significant correlation between the loss of normal membranous expression of p120 and increased grade (P < 0.001) and T stage (P < 0.001). The abnormal expression of p120 was correlated with poor survival (P < 0.05). Our data indicate that the E-cadherin-p120 complex may be a useful prognostic marker in bladder cancer.

Effect of testosterone administration, pre- and postnatally, on the immune system of rats.

This study was undertaken to investigate and compare in vitro and in vivo immune parameters between female and male rats. We analysed the T-cell proliferative responses to syngeneic and allogeneic cellular antigens (syngeneic and allogeneic mixed lymphocyte reaction), as well as the IgG levels in the sera of our study groups. It has also been studied the influence of gonadectomy and the effect of testosterone administration pre- and postnatally on the above parameters. Our findings showed that hormonal manipulations, can alter the differences observed in immune response between female and male rats. In addition, it is demonstrated that pre- and postnatal sexual steroid manipulations could provoke long lasting immunological effects.

Non-specific autoantibodies in cardiomyopathies and myocardial infarction.

In the present study we evaluated the importance of autoimmune mechanisms in cardiomyopathies. Sera from 22 patients with dilated cardiomyopathy, 23 patients with hypertrophic cardiomyopathy, 24 patients with myocardial infarction and 40 apparently healthy blood donors were tested with an immunoassay method for the presence of autoantibodies against dsDNA, ssDNA and cardiolipin. Elevated values of autoantibodies, mainly of the IgG subtype, were obtained in a high percentage of patients with cardiomyopathy (30-50%), as compared to the control group (5%). The incidence of these autoantibodies has been found significantly high in both groups of dilated and hypertrophic cardiomyopathies. Although further investigation is needed, it is concluded that the detection of these autoantibodies may contribute in the better understanding of the pathogenesis of cardiomyopathies and could be a useful tool for the diagnosis, follow up and prognosis of these patients.