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Biomedical subjects

A L Leone

Publications and source records attributed to A L Leone.

15 recordsLinked to original sources
PubMed1992

Study of HLA segregation in 479 thalassemic families.

479 families, each with a proband affected by homozygous beta-thalassemia, were typed for HLA. 224 families with a total of 1020 members were typed for the HLA-A, B, C, DR and DQ loci and 255 families with 1046 family members, were typed for the HLA-A, B, and C loci. Altogether, 896 A, B, C, DR and DQ haplotypes and 1020 A, B and C haplotypes were defined. At the same time, 120 healthy unrelated individuals from the same population were typed and used as controls. The analysis of the results was carried out at antigen, allele, haplotype, genotype and sex ratio level with the aim of looking on the one hand, for the existence of heterogeneity between the probands, the unrelated individuals and the healthy siblings and, on the other, for the existence of any distortion whatsoever of the HLA segregation in either the probands or in the healthy siblings in respect of the expected values according to the Mendelian equilibrium. No significant differences were evident between the probands and the controls by the tests carried out at different levels of the HLA system. This leads us to exclude the existence of an association between beta-thalassemia and HLA in the population studied. Moreover, the analysis of the transmission of the alleles, the haplotypes, the genotypes and the sex-ratio by parents to both affected and to healthy children did not show any clear evidence of segregation distortion in respect of the theoretical values.

Alleles↗
PubMed1989

Hodgkin's disease presenting in 1 of 4 siblings affected by hereditary spinocerebellar ataxia: clinical, immunological and genetic study.

One of 4 siblings affected by hereditary spinocerebellar ataxia (HSCA) of Marie's type developed Hodgkin's disease (HD): the stage was IV B, the patient was submitted to conventional chemo- and radiotherapy and achieved complete remission. An accurate clinical, genetic and immunological study was carried out on all his family, including a complete HLA typing, a chromosome study, the immunophenotyping of peripheral blood mononuclear cells (PBMC), the PBMC response to polyclonal mitogens, to interleukin 2 (IL-2), to the association of PHA + IL-2 and the evaluation of the IL-2 receptor expression. No association was clearly demonstrable between an HLA haplotype and HSCA, while the patient with HSCA and HD was HLA-B18- and DQw3-positive (the last at homozygous level), two antigens known to be strongly associated with HD, mainly among the Sardinian ethnic group. The mode of inheritance of HD susceptibility is however completely different from that of Marie's HSCA. The chromosome study did not show any characteristic pattern of the karyotype, neither of the HSCA affected nor of the unaffected members. The immunological investigations did not elucidate any characteristic behavior of the family members, apart from the typical findings of HD seen on patients with HSCA and HD. Our study could not demonstrate any genetic and/or immunologic common background shared by the two diseases, HSCA and HD. Their coexistence in our patient, although the statistic probability is very low, seems to be a fortuitous coincidence more than the result of a common genetic and pathogenetic mechanism.

Adult↗
PubMed1988

Familial chronic B-cell malignancy. Hairy cell leukaemia in mother and daughter.

Two familial cases of hairy cell leukaemia are reported: a daughter, 44-years-old, with a very unusual ultrastructural pattern found in hairy cells, the "tubuloreticular inclusions", and her mother, 71-years-old, who was affected six years later. Routine laboratory investigations, cytochemical and cytogenetic studies including HLA typing, as well as in vitro proliferative response of peripheral blood mononuclear cells (PBMC) to polyclonal mitogens and to exogenous interleukin 2, were performed. The immunological characterization by assessing the cell surface phenotypic markers with monoclonal antibodies and transmission electron microscopy (TEM) investigations were also carried out. In case 2 all tests were performed both on PBMC and on the bone marrow cells. To the best of our knowledge this is one of the first reports of such familial association. The possibility that genetic factors might play a role in the etiology of leukaemia in man is discussed: in our two cases, however, cytogenetic studies did not support this, while HLA typing revealed a non-significant association of HCL with DQw3 allele. Alternatively, an environmental factor has been considered, and a viral infection-perhaps by a retrovirus of the HTLV family has been suggested as tubuloreticular inclusions have been found in both hairy cell leukaemia, as reported, by us, and AIDS-LAS. However, a long time elapsed between the manifestation of HCL in the daughter and in the mother, and as the two patients had not been living together at that time, the possibility of a viral transmission seems minimal. The results of TEM and of immunological investigations are presented and discussed. Both, but particularly the latter, support the B cell nature of the hairy cell.

Adult↗
PubMed1985

Total IgE in newborns treated prophylactically with conalbumin.

Conalbumin has been used as a prophylactic treatment in artificially fed babies to prevent enteritic infections. Conalbumin being a heterologous protein, it could have sensitizing properties. The trial here reported demonstrated that when conalbumin-treated milk was fed to 15 such babies for 60 days the values of total IgE, as determined by the radioimmunoassay method, remained within the normal range.

Conalbumin↗
PubMed1979

Interference of levamisole with inhibition of E-rosette formation by Hodgkin's disease and systemic lupus erythematosus cytotoxic sera.

A new system has been used to test the influence of levamisole on T-cell function. Evidence has been produced that prior exposure to the drug "protects" normal human peripheral blood lymphocytes from the inhibition that cytotoxic sera from patients with Hodgkin's disease and systemic lupus erythematosus exhibit on their E-rosette-forming capacity. Also, damage of this T-cell function already induced by Hodgkin's sera may be partially corrected.

Cytotoxicity, Immunologic↗
PubMed1977

HLA antigens and erythrocyte glucose-6-phosphate dehydrogenase (G-6-PD) deficiency in Sardinia.

The frequency of 17 HLA antigens from locus A and locus B has been evaluated by microlymphocytotoxicity test in a population of 233 subjects (157 normal and 76 with deficiency of glucose-6-phosphate dehydrogenase [G-6PD]in red cells) from a village of Sardinia, a mediterranean island relatively close to continental Italy. It appears that G-6-PD-deficient people show a frequency of some HLA antigens (A2, A10, B12, BW35) significatively different from normal Sardinian subjects but close to (A10, BW35) or higher (A2, B12) than that of subjects from peninsular Italy.

Cytotoxicity Tests, Immunologic↗
PubMed1977

[Histotypes HL-A in the Ligurian population of the islet San Pietro in Sardinia].

The frequency of 17 HLA antigens of loci A and B has been studied by microlymphocytoxicity test in 114 subjects of islet S. Pietro, very close (a few miles) to South-west of Sardinia, but genetically very different from it, deriving the population from a region (Liguria) of continental Northern Italy. The data have been compared with those of a village of Southern Sardinia and with those of a population living in Liguria (continental Italy). The results confirm the striking genetical difference between people of the two islands (S. Pietro and Sardinia) and the close similarity between S. Pietro and Liguria from the genetical point of view.

Cytotoxicity Tests, Immunologic↗
PubMed1976

[Comparison between anti-lymphocyte antibodies in systemic lupus erythematosus and in Hodgkin's disease].

Anti-lymphocyte antibodies of cold-reactive IgM-type in Systemic Lupus Erythematosus (SLE) and IgG-type in Hodgkin's disease (HD) by means of immunofluorescent technique have been demonstrated. The contemporaneous attachment of SLE and HD sera on selected peripheral lymphocytes demonstrate that the target cell is T-lymphocyte and that the two kinds of antibodies coat the same cell. Co-capping experiments have shown that the phenomenon has the same behaviour as regard to SLE and HD antibody, indicating that the antigen is the same. Hypothesis about the meaning of these antibodyies have been made.

Antibody Formation↗
PubMed1976

[Presence of alpha-2-macroglobulin on the membrane of peripheral human blood lymphocytes : a new lymphocyte maker].

The presence of alpha-2-macroglobulin (alpha-2-M) on the surface of peripheral blood lymphocytes from normal human subjects and from patients with chronic lymphatic leukaemia (CLL) and with ataxia-teleangectasia was studied by indirect immunofluorescence technique. Same experiments were done on purified subpopulations of normal blood peripheral lymphocytes (B and T). The percentage of alpha-2-M bearing lymphocytes is 17 +/- 6% as regard to normal subjects (Ig-bearing cells are 14%): in CLL the percentage of alpha-2-M bearing cells generally is significantly lower than that of Ig-bearing cells (IgM-IgD). On selected subpopulations, 90% of alpha-2-M bearing cells are present among non T-cells and only 5% among T-cells (probably due to not absolute purification). Blocking experiments using anti-Ig sera did not affect significantly the percentage of alpha-2-M bearing cells and using anti-alpha-2-M sera did not affect that of Ig-bearing cells. The percentage of E-rosette forming cells is not affected by pretreatment of peripheral lymphocytes with anti-Ig and/or anti-alpha-2-M sera. Hypothesis is set forth that alpha-2-M bearing cells could be a lymphocytes subpopulation made by a subgroup of B-cells and by K-cells, taking part in that immunoregulatory system in which collaborate many serum alpha-globulins and T-suppresor cells.

Antibody Formation↗
PubMed1976

Anti-lymphocyte antibodies in systemic lupus erythematosus and in Hodgkin's disease: a comparison by immunofluorescence.

Anti-lymphocyte antibodies of IgM type (cold reactive) in systemic lupus erythematosus and of IgG type (not cold reactive) in Hodgkin's disease have been demonstrated by immunofluorescence to attach the same target cell (T-lymphocyte.) The same behaviour of both kinds of antibodies in "co-capping" experiments confirm that the antigen on the cell surface is the same. Hypothesis about the meaning of this phenomenon are made.

Antilymphocyte Serum↗
PubMedDate not supplied

Serological and molecular studies of HLA in insulin-dependent diabetes mellitus in Sardinia.

This study was carried out in Sardinia, an Italian region with a very high IDDM incidence. HLA class I and class II antigens were studied in 97 unrelated IDDM patients, 33 complete families with at least one affected member each, and 559 healthy controls. Molecular typing of the DQB1 alleles was carried out in 31 patients and 61 controls. The haplotypes were determined by family studies. The HLA-DR3, DQw2, and DR4 antigens were positively associated with IDDM. The DR3 antigen was nearly always associated to B18 and frequently carried by the extended haplotype A30 Cw5 B18 3F130 DR3 DQw2. The genotype analysis of the patients showed a strong increase of the DR3/DR4 heterozygotes with a relative risk higher than that of the DR3 and DR4 homozygotes. The DR2 antigen was negatively associated with IDDM in the central island districts but not in the southern districts. The DQB1 molecular analysis showed only three alleles in the patients: DQB1*0201 (75.8 per cent), DQB1*0302 (16.1 per cent), and DQB1*0502 (8.1 per cent). These alleles are non Asp 57, so it would seem that nearly if not all Sardinian IDDM patients are NA/NA homozygotes. The DQB1*0502 allele, extremely rare in other Caucasian populations, represents in Sardinia about 70 per cent of the HLA-DR2 haplotypes, contributing to the increase of the pool of IDDM susceptible genes. Moreover it is carried in 27 per cent of the DR2 positive individuals with the extended haplotype A2 Cw7 Bw58 3F31 DR2 DQw1.AZH.

Alleles↗