Biomedical subjects

M A Modica

Publications and source records attributed to M A Modica.

30 records · Page 2Linked to original sources

PubMed1990

Soluble interleukin-2 receptor in vitro production by mononuclear cells from Hodgkin patients.

Lymphocytes of patients with Hodgkin's disease have a deficient production of Interleukin-2. Recently, a soluble form of the receptor for IL-2 has been demonstrated in human sera and in vitro-stimulated culture supernatants from human T lymphocytes. In the present paper we report the production of soluble IL-2R from peripheral blood mononuclear cells in H.D. The unstimulated MNC of patients released more sIL-2R than controls. No difference was observed between PHA-stimulated MNC of patients and controls. These preliminary findings suggest that soluble IL-2R may be provide a new tool for the study of immunological dysregulation in H.D.

Adolescent↗

PubMed1989

Interleukin 2 and soluble interleukin 2-receptor secretion defect in vitro in newly diagnosed type I diabetic patients.

In this study, we investigated whether an interleukin 2 (IL-2) secretion defect by peripheral blood mononuclear cells (PBMCs) after in vitro stimulation with phytohemagglutinin (PHA-M) occurs in either newly diagnosed or long-standing type I (insulin-dependent) diabetic patients and whether it is accompanied by a dysregulation of soluble IL-2-receptor (IL-2RS) production. PBMC cultures (2.5 x 10(6) cells), unstimulated or stimulated with PHA-M (25 micrograms/ml), from 20 type I diabetic patients (10 with time since onset less than 3 mo and 10 with long-term diabetes of less than 3 yr) and 10 control subjects were studied for the production of IL-2 and IL-2RS in their respective supernatants. No difference was found in IL-2 production in unstimulated cultures of type I patients compared with control subjects, although a significant decrease from PHA-M-stimulated cultures were seen (newly diagnosed, 1.7 +/- 0.3 ng/2.5 x 10(6) cells; long-standing, 2.2 +/- 0.3 ng/2.5 x 10(6) cells; P less than .001 and P less than .05, respectively) compared with control subjects (3.6 +/- 0.4 ng/2.5 x 10(6) cells). In regard to the production of IL-2RS, no difference exists for unstimulated cultures, whereas, after PHA-M stimulation, both newly diagnosed and long-term-diabetic patients showed a decrease in the IL-2RS levels (318 +/- 50 and 331 +/- 62 U/2.5 x 10(6) cells; P less than .02 and P less than .05, respectively) compared with normal subjects (463 +/- 34.2 U/2.5 x 10(6) cells). Thymus-activated cell phenotypes confirmed the T-lymphocyte activation after a 48-h culture period.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1989

Blood IgA, IgM and IgE levels are influenced by sex and HLA phenotype.

In the present study we have investigated the HLA-B8,DR3-associated control of serum IgA levels in 110 randomly selected HLA-typed healthy subjects. Serum IgG, IgA, IgM and IgE levels were measured in all individuals. The values were analyzed according to age, sex and HLA-DR phenotype. No correlation between age and serum IgA, IgM and IgE levels was found in our homogeneous sample, since all subjects studied were in a narrow age range, i.e. 20-49 years. In contrast, a significant positive correlation was found for IgG levels. The mean IgM level was significantly higher in females than in males, whereas the mean IgA and IgE levels were significantly lower in females. HLA-DR2-positive subjects displayed the significantly highest levels of serum IgE, whereas HLA-B8,DR3-positive subjects showed the significantly lowest levels of serum IgA. Thus, our results show that in our random sample sex and DR phenotype are involved in the control of serum IgA, IgM and IgE levels. The genetic control of sex and HLA-B8,DR3 of serum IgA levels could be related to the high incidence of autoimmune disorders among females and HLA-B8,DR3-positive individuals. The results showing higher levels of IgE in HLA-DR2-positive subjects might be consistent with the observation of a strong association between HLA-DR2 and IgE immune hyperresponsiveness to some allergen(s).

Adult↗

PubMed1988

HLA-Cw4 association with acute lymphoblastic leukaemia in Sicilian patients.

The HLA frequencies of 50 Sicilian patients affected with acute lymphoblastic leukaemia (ALL) were examined. The frequency of Cw4 antigen was significantly increased in patients. Thus results obtained in our homogeneous population confirm in part previous reports suggesting that Cw4-related genetic factors might be involved in the susceptibility to aetiological or pathogenetic mechanisms which play a role in some haematological malignancies.

Adolescent↗

PubMed1988

Dissociated production of interleukin-2 and immune gamma-interferon by phytohaemoagglutinin stimulated peripheral mononuclear cells in type 1 (insulin-dependent) diabetes.

In order to analyze the first steps of T cell activation in type 1 diabetes we studied in vitro IL-2 and gamma-IFN production by peripheral blood mononuclear cells after 24 h PHA stimulation. There was a significant decrease in IL-2 production by mononuclear cells of the diabetic patients with respect to the controls. No significant difference was observed between the diabetic patients and the healthy subjects as regards gamma-IFN production. These observations may be interesting in relation to the pathogenetic mechanisms involved in type 1 diabetes. In particular, normal gamma-IFN production may indicate integrity of the natural killer circuit.

Adolescent↗

PubMed1988

HLA-DR1 and HLA-DR3 phenotypes and insulin antibody production in diabetic Sicilian patients.

We have evaluated the role played by HLA antigens in the control of humoral response to exogenous insulin in a sample of Sicilian insulin-dependent diabetes mellitus patients. The results demonstrate that HLA-DR1-positive patients show the highest mean values of insulin antibody, whereas HLA-B18,DR3-positive patients show the lowest. Thus, present observations show that HLA-DR1- and HLA-DR3-linked genes do play opposite roles in the humoral immune response to an exogenous protein, i.e. injected insulin. These results might be consistent with the findings concerning the mechanisms involved in the resistance and/or susceptibility to immunological diseases. In this regard, the fact that no immunological spontaneous disorder has been shown to be associated with HLA-DR1, whereas several have been shown to be associated with HLA-DR3, is intriguing.

Adolescent↗

PubMed1987

HLA-DR-linked genes are involved in the control of T lymphocyte blood levels.

In the present study we have evaluated the association of HLA-DR antigens with circulating leukocyte levels in 113 HLA-typed normal healthy Sicilians. By two methods of statistical analysis (chi 2 test and Student t test) it has been possible to demonstrate clearly a significant association between high levels of mononuclear cells and HLA-DR1 phenotype. This increased number of mononuclear cells in HLA-DR1-positive subjects is due to the increase of blood T cells, whereas monocytes, B cells, neutrophils, and eosinophils are unmodified. These data are consistent with the hypothesis that HLA-DR-linked gene(s) are involved in the control of blood T-cell levels.

Eosinophils↗

PubMed1987

HLA antigens in Sicilian patients affected by chronic myelogenous leukaemia.

HLA antigens were investigated in Sicilian patients with chronic myelogenous leukaemia (CML) and in Sicilian healthy controls. The frequency of the HLA-DRw6 antigen was significantly decreased in the group of patients. These results suggest that DRw6 may be a marker for decreased susceptibility to the etiological or pathogenic mechanism(s) which produce CMLs.

Gene Frequency↗

PubMed1987

MHC-linked genetic factors (HLA-B35) influencing recurrent circumoral herpetic lesions.

The frequencies of HLA-A, B, C, DR, and DQ lymphocyte alloantigens were determined in 31 Sicilian patients with recurrent herpetic lesions (RHL) and compared to frequencies observed in normal individuals. A significant negative association was found for HLA-B35 (pc = 0.049). The relationships between HLA and immune responses to viral infections are discussed in light of the results revealed by the present investigation suggesting that HLA-linked genetic factors may play a role in the pathogenesis of RHL. The results seem to indicate that genes in the major histocompatibility complex (MHC) are influential against developing RHL.

Adult↗

PubMed1984

[Characterization of cell suspensions adhering to nylon obtained from mononuclear cells in toto or depleted of monocytes].

The aim of this work was to evaluate the effect of monocyte depletion on the preparation of B cell enriched suspensions for DR typing. Nylon fiber adherent-cells obtained from total, or monocyte depleted, MNC were identified using different surface markers and cytochemical staining (SIg, DR, ANAE). The results demonstrate that no significant improvement in B enrichment is obtained by monocyte depletion.

Antigens, Surface↗

PubMedDate not supplied

HLA-B8,DR3 phenotype and lymphocyte responses to phytohaemagglutinin.

Several reports have shown that HLA-B8,DR3 positive subjects may display some changes in immune parameters when compared with HLA-B8,DR3 negative ones and are prone to develop several immunological diseases. In the present study we have analysed the proliferative response to phytohaemagglutin (PHA) in HLA-typed healthy subjects. A twin method was also employed to assess the role of genetic and environmental factors in the regulation of the response to the mitogen. It was not possible to demonstrate any difference in proliferative response to optimal doses of PHA between groups of subjects carrying or not carrying the HLA-B8,DR3 phenotype. When suboptimal responses were studied, however, the results showed that lymphocyte responses were significantly decreased in HLA-B8,DR3 positive subjects compared with the negative ones. Moreover, the experiments performed with twins demonstrated that environmental factors were more important than genetic factors in the proliferative response to mitogen. The fact that the HLA-B8,DR3 phenotype affects the suboptimal response to PHA although environmental factors are more important than genetic factors in the response to the mitogen seems of some interest. However, these results could be consistent with the high incidence of autoimmune disorders among HLA-B8,DR3 positive individuals.

Adult↗

PubMedDate not supplied

IgD serum levels are influenced by HLA-DR phenotype.

In the present paper we have evaluated IgD serum levels of 84 randomly selected HLA-typed healthy Sicilians. The values were analysed according to age, sex and HLA-DR phenotypes. No correlation between age and IgD serum levels was found in our population since all subjects were in a narrow age range. Furthermore, no significant association was found between IgD serum levels and gender of studied subjects. The evaluation of IgD serum levels according to HLA-DR phenotypes revealed that HLA-DR1 positive subjects displayed significantly higher values. These results are in agreement with previous reports showing that HLA phenotypes may be involved in the control of serum immunoglobulin levels. Furthermore, present data strengthen our suggestion that HLA-DR1 phenotype is related to the 'high responder' immunological profile.

Adult↗