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J Seignalet

Publications and source records attributed to J Seignalet.

At least 37 records · Page 2Linked to original sources
PubMed1984

[HLA-A, B, C, and DR typing in rheumatoid polyarthritis].

HLA-A, B, C typing were performed in 72 caucasians with rheumatoid arthritis. HLA-DR typing were accomplished in 40 patients among these 72 subjects. DR4 was clearly increased with a frequency of 55 p. 100 versus 18 p. 100 in controls. We did not find an association between DR4 and the presence of rheumatoid factor. Clinical and biological signs are similar in rheumatoid arthritis with and without DR4. Two other HLA antigens, B40 and Cw3, were increased and their frequency was twice as high in patients as compared with controls. A synthesis of six studies published in the world confirms the elevation of B40 in this disease and later on suggests the elevation of Cw3 which is often linked with B40. The association of rheumatoid arthritis with B40 and Cw3 can be explained by a linkage disequilibrium between DR4 and B40 on the one hand, between DR4 and Cw3 on the other hand.

Adult↗
PubMed1984

Influence of HLA-A, B, and DR matching on the outcome of kidney transplant survival in preimmunized patients.

The outcome of 893 prospectively typed (HLA-A, B, and DR) and matched cadaveric kidney transplants--all first grafts, with patients being transfused before transplantation--was studied using actuarial survival methods. The effect of HLA-A, B and DR matching was only found to be significantly beneficial to graft survival in the group of 289 presensitized recipients: 70% and 43% graft survival at two years in the case of best-matched (4-6 HLA-A, B, and DR) identities versus mismatched (0 and 1 HLA-A, B, and DR) identities, respectively (P = 0.05). Although a cumulative effect of matching for antigens belonging to the 3 HLA-A, B, and DR series was observed among the group of preimmunized recipients, a trend arose in favor of the prominent role of the HLA-B alleles. No significant difference related to HLA matching was observed in the group of nonsensitized recipients. These results confirm previous observations and support efforts to give priority for matched kidneys to preimmunized patients.

Actuarial Analysis↗
PubMed1984

[Immunological selection of donors and recipients in renal grafts: antibodies].

It appears that a wide range of antibodies must be taken into account among future recipients of renal allografts. On one hand, the hazard of hyperacute rejection induced by warm allo-antibodies directed against donor's HLA-A, B antigens is well known. It is probable that warm allo-antibodies directed against donor's Ia (HLA-DR) antigens are also harmful. On the other hand, anti-T or B lymphocytes cold auto-antibodies appear neutral, whereas some studies suggest the possibility of enhancing antibodies which may be anti-idiotypic antibodies.

Antibodies↗
PubMed1984

[Immunologic selection of renal transplant donors and recipients: blood transfusions].

Blood transfusions clearly improve the prognosis of cadaver kidney transplantation. The percentage of graft survival at one year is increased, about + 25%. Preoperative transfusions are effective, whereas peroperative transfusions are ineffective. The following technique seems to be good. Each patient should first receive 5 blood transfusions over a short time lapse, and then one unit of blood from time to time, two times per year for example. The blood must be less than three days old and must contain leucocytes. Transfusions induce, in a few hemodialysed patients, an anti-HLA immunisation. It is thus necessary to choose a donor with a negative cross-match. Transfusions induce in many patients a better tolerance for kidney transplant. This tolerance is perhaps immunologically specific. Blood transfusions are also useful for the selection of related donors HLA semi identical with recipients. The recipient is transfused several times with donor's blood. Transplantation is only performed when the cross-match remains negative and then leads to a high percentage of success.

Antibody Formation↗
PubMed1983

[Relation between Ia antigens and Ir gene products. A theory on the development of the immune response].

To explain the relations between Ia and Ir, we propose the following hypothesis. It would exist an antigen specific factor released by T lymphocytes. This factor would be constituted by two parts: a variable fragment forming the antigenic receptor of T cells and coded by Ir genes, a constant fragment transmitting a helper or suppressor signal and carrying Ia antigens. Ia antigens would allow a mutual recognition between macrophages, T lymphocytes and B lymphocytes and a recognition by these cells of some mediators released during immune response. Ir genes products would allow the antigen recognition, if they correspond to the antigenic receptor of T lymphocytes.

Animals↗
PubMed1983

[HLA-DR determinations in peripheral psoriatic rheumatism].

The distribution of 7 HLA-DR antigens was compared in 25 patients with peripheral psoriatic rheumatism and in 100 healthy controls. DR7 frequency was found to be significantly increased in patients: 60%, against 27% in controls (Pc = 0.021). Peripheral psoriatic rheumatism, which is related with HLA antigens B17, B13, Bw38 and Cw6, is probably also associated with DR7.

B-Lymphocytes↗
PubMed1983

[Relations between Ia antigens and the products of Ir genes. A theory of the evolution of the immune response].

To explain the relations between Ia and Ir, we propose the following hypothesis. It would exist an antigen specific factor released by T lymphocytes. This factor would be constituted by two parts: a variable fragment forming the antigenic receptor of T cells and coded by Ir genes, a constant fragment transmitting an helper or suppressor signal and carrying Ia antigens. Ia antigens would allow a mutual recognition between macrophages, T lymphocytes and B lymphocytes and a recognition by these cells of some mediators released during immune response. Ir genes products would allow the antigen recognition, if they correspond to the antigenic receptor of T lymphocytes.

Animals↗
PubMed1983

[The importance of HLA typing in cases of disputed paternity].

In dispute paternity, the biologists must reply to two questions: 1. Is the paternity excluded or possible? 2. If it is possible, what is its probability? Valid answers can be given, using several genetic markers, among which HLA genes are specially interesting. Looking at HLA-A, B, C, DR typing of child, mother and presumed father, we propose a method which allows a direct calculation of paternity probability. Crossing over between HLA genes in presumed father and in mother are also considered in this method. In our experience, adding the date provided by the HLA genes and other genetic markers, we obtained, either formal exclusions, or possible paternities with a probability almost always higher than 90%.

Female↗
PubMed1982

[Immunologic selection of donors and recipients in renal graft: transplantation antigens ].

For the immunologic selection of donors and recipients in renal transplantation, several antigens must be considered: ABO and Lewis antigens identified by red cell typing, HLA-A, HLA-B and HLA-DR antigens identified by leucocyte typing and HLA-D antigens explored by mixed lymphocyte reaction (MLR). In renal grafts with living related donor, the best donor is ABO compatible, HLA-A and B identical, MLR negative with the recipient. In renal grafts with cadaver donor, the best recipient is ABO and Lewis compatible and must present the greatest number of HLA-A, B and DR identities with the donor. The number of cadaver donors is relatively small and the selected recipient does not however present a good HLA compatibility with his donor.

Blood Grouping and Crossmatching↗
PubMed1981

[Our experince with antiglobulin consumption (Dixon test) in the study of antibodies bound to platelets].

We measured the quantity of IgG bound to platelets (IgGP) by the antiglobulin consumption test (Dixon technic). In controls, the IgG level did not exceed 10 X 10(-15) g for one platelet. The amount of IgGP was often incraeased (more than 10 X 10(-l5) g) in some autoimmune diseases as lupus erythematosus, chronic lymphocytic leukemia and chronic active hepatitis. Among 26 patients presenting an idiopathic thrombocytopenic purpura (ITP) with a low number of platelets, 21 (77%) had a high titer of IgGP. In 6 ITP in remission, the IgGP titer was normal. After a review of the different technics detecting the IgG bound to platelets, we explain why we choose the antiglobulin consumption. This test is excellent for the research of anti-platelets auto-antibodies in ITP. Yet, the reaction remains negative in a minority of ITP. Several explanations are possible: low quantity of IgGP, presence of other anto-antibodies as IgM or IgA, cellular auto-immunity anti-platelets without antibodies, non immunologic ITP.

Antibodies↗
PubMed1980

[The search for anti-B cell antibodies and HLA-DR typing in Montpellier].

Screening of anti HLA-DR sera was obtained without absorptions of sera on platelets. In the first place, all our sera were tested by a lymphocytotoxicity technic on 20 T lymphocytes varieties, containing all the known HLA-A, B, C antigens. Anti HLA-A, B, C antibodies are isolated and excluded. Other sera are tested on 20 B lymphocytes varieties and positive sera are harvested, which often contains anti HLA-DR antibodies. HLA-DR typing were performed on 100 healthy not related individuals. The sera were, some from different laboratories (France-Transplant, Lyon), others from Montpellier (37 local sera). A lymphocytes were isolated by adhesivity on nylon wool column. A one stage lymphocytotoxicity technic was used for typing. Anti HLA-DR sera often are polyspecific and often contain antibodies with unknown specificity. The frequency of seven classical antigens, from DRw1 to DRw7 was established in the Languedoc populations. The antigens distribution is close to that observed in Europe, except for DRw1 which is more frequent. Several cross reactions between HLA-DR antigens were noticed.

Antibodies↗