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C Raffoux

Publications and source records attributed to C Raffoux.

At least 73 records · Page 4Linked to original sources
PubMed1989

[HLA class II typing of peripheral blood B lymphocytes separated using monoclonal antibodies].

The different methods proposed for preparation of B lymphocyte suspensions are not always simple, rapid and reliable. Presence of monocytes in the B cell suspension makes difficult HLA-DQ typing. For these reasons we propose a method using monoclonal antibodies (McAb) and complement to lyse the non B cells. Mononuclear cells, isolated from peripheral blood by Ficoll-Hypaque, are suspended in a mixture of anti-CD2, CD3, CD11b (OKM1 recognizing monocytes and granulocytes) McAb. This method of preparation of B cell suspension is rapid and provide better typing reactions than did the suspensions prepared by depletion of sheep red blood cell rosetting cells.

Antibodies, Monoclonal↗
PubMed1989

[HLA class II typing in chronic myeloid leukemia with the complement fixation test using phytohemagglutinin-activated lymphocytes in the presence of interleukin 2 and gamma interferon].

In 23 cases of chronic myelogenous leukemia (CML) in remission, HLA class II typing was performed by complement fixation technique on phytohemagglutin (PHA) activated lymphocytes. In 10 cases satisfactory results were obtained, whereas in 13 cases the cells were weakly or non reactive, making impossible a correct determination of HLA-DR,DQ specificities. In the 13 cases a conditioned medium containing Interleukin-2 (Il-2) and gamma interferon (IFN) was added to PHA, inducing a good HLA class II reactivity and making possible a satisfactory definition of HLA-DR,DQ specificities. The complement fixation technique on lymphocytes cultured with PHA, Il-2 and gamma IFN made possible a correct HLA-DR,DQ typing in 23 consecutive cases of CML, while such a typing is often difficult or impossible when using the microlymphocytotoxicity technique on B lymphocyte targets.

Antilymphocyte Serum↗
PubMed1989

Definition of a new supertypic HLA class II determinant (LAR) associated with HLA-DR2 and -DR7.

A serum from a patient (LAR), immunized by pregnancies and blood transfusions, reacted with cells carrying HLA-DR2 and/or -DR7 specificities (titer 1:200-1:1000). Absorption-elution experiments showed that the allo-serum recognized a determinant shared by DR2 and DR7 cells. The high correlation coefficients (0.90-1) with these specificities suggested that the supertypic specificity LAR was carried by the first DR molecule encoded by DRB1 gene. LAR is another example of new supertypic specificities, reflecting structural homologies between alleles at HLA class II loci.

Epitopes↗
PubMed1989

HLA typing with monoclonal antibodies: evaluation of 356 HLA monoclonal antibodies including 181 studied during the 10th International Histocompatibility Workshop.

During the 10th International Histocompatibility Workshop (10th WS), 181 HLA MoAbs were studied using lymphocytotoxicity micro-technique (LCT) and/or enzyme immuno-assay (EIA), and their capacity to serve as typing reagents was evaluated. 129 MoAbs were tested by both techniques. Results obtained with 92 class I and 86 class II polymorphic MoAbs (10th WS) were compared to published data concerning 180 class I and 176 class II polymorphic MoAbs, listed in an HLA-MoAbs Register maintained in our laboratory. The following conclusions can be proposed: 1/HLA-A, B typing by LCT with MoAbs is possible for about 14 specificities. Some specificities are clearly recognized (HLA-A3, B8, B13, Bw4, Bw6), others are recognized as cross-reacting groups (B7+27+w22+40), others are not currently recognized by any MoAb with restricted specificity (B5, B15). Several MoAbs confirmed the existence of shared epitopes between products from a single locus (A2-A28, A25-A32), or from A and B loci (A2-B17, Bw4-A9-A32). A single HLA-Cw MoAb has been described. 2/HLA class II typing by LCT with MoAbs is more difficult than class I typing. DR2, DR3, DR4, DR5 and DR7 as well as DRw52 and DRw53 are well defined; other DR specificities are poorly or not at all defined. Particular associations (DR1+DR4, DR3+DRw6, all DR except DR7) are recognized by several MoAbs. All DQw specificities are well recognized, including new specificities defined only by MoAbs: WA (DQw4), TA10 (DQw7), 2B3 (DQw6+w8+w9). Only two HLA-DP MoAbs have been described. 3/Satisfactory results, similar to those of LCT, were obtained with EIA using lymphoid cell lines as targets. 4/Human MoAbs (12 in the Register) are satisfactory typing reagents. They could represent in the future a significant contribution to HLA typing with MoAbs.

Antibodies, Monoclonal↗
PubMed1989

Genetic susceptibility to leprosy on a Caribbean Island: linkage analysis with five markers.

Our recent segregation analysis, carried out on 27 large pedigrees from a Caribbean island (Desirade), has shown the presence of recessive major gene(s) controlling susceptibility to leprosy per se and nonlepromatous leprosy, respectively. Linkage analysis was performed between each of these two detected genes and each of five markers typed in the Desirade population: HLA, ABO, Rhesus, Gm and Km. No positive significant lod score was observed. However, for leprosy per se close linkage was excluded with Rhesus and Gm (and also with ABO and HLA, considering a lower value for the frequency of the gene controlling susceptibility to leprosy per se). The highest lod score, although not significant, was obtained between the gene for nonlepromatous leprosy and ABO. Our overall results, joined with previous studies and experimental data, suggest that the gene controlling susceptibility to leprosy per se and that controlling susceptibility to nonlepromatous leprosy might be different, acting at successive stages of the immune response to infection with Mycobacterium leprae.

ABO Blood-Group System↗
PubMed1989

Anti HTLV-I antibodies and HLA phenotypes in the West Indies.

Sera of supposedly healthy blood donors were screened for the presence of anti HTLV-I p24 antibodies, and HLA typing for A, B, C and DR antigens was performed for 68 seropositive subjects and 92 seronegative controls. HLA phenotypes of the two groups were not significantly different but the level of the antibody response was related to the antigens of the HLA-B (P = 0.02) and -C loci (P = 0.003). Subjects with HLA-B12 or -B21 antigens had lower titres than the others. Subjects with HLA-Cw2 or -Cw7 antigens had higher titres than the others, but only the difference between HLA-B12 positive and negative subjects (P = 0.002) remained significant at the alpha = 0.10 level if the classical, although conservative, Bonferroni procedure was used to correct for the number of comparisons performed.

Adult↗
PubMed1989

French national bone marrow donor registry and interaction with foreign files.

A program to obtain volunteer bone marrow donors has been developed. A total of 33.000 HLA-A, B typings were performed. A search for 527 patients has been initiated. Among these, 44% are suffering from chronic myelogenous leukemia. For 23% of the patients no HLA-A, B identical donor has been identified. Out of the 401 patients who had HLA-A, B identical donor 35% (139/401) had one or more HLA-A, B, DR identical donors. In one of the transplant center, when the mixed lymphocyte culture (MLR) was carried out between 219 donors and 79 patients, a transplantation for 20/79 patients has been proposed. Up to now, transplantation has been carried out in 31 patients whom donor searches were initiated.

Bone Marrow Transplantation↗
PubMed1989

[Study of the HLA system and glyoxalase in 31 insulin-dependent diabetics free from micro and macro-angiopathies after more than a 20-year development].

Insulin-dependent diabetics are not equal as concerns vascular complications. Many factors have been incriminated. The object of this study was to determine if a genetic factor protected the insulin-dependent diabetic from vascular complications. The population included 31 unrelated, white insulin-dependent diabetic subjects (18 females and 13 males), with diabetes of over 20 years' duration (21 to 43 years, m +/- SD 27.82 +/- 6.03 years; age at diagnosis: 2 to 57 years, m +/- SD 22.7 +/- 15.19 years). The absence of vascular lesions was checked for by the following investigations: visual acuity, fundoscopic examination, retinal fluorescein angiography (Canon F 60 Z), systolic pressure on the thigh and ankle, Doppler velocimetry, plethysmography of the lower limbs, serum creatinine level, urinary protein. The study of the HLA A, B, DR specificities was carried out using the Tersaki microlymphocytotoxicity assay, those of C4 by high voltage gel electrophoresis followed by hemolytic detection, those of B1 using Alper's method and those of glyoxalase by gel electrophoresis followed by a glutathione redox reaction in order to test for a marker for a possible protective genetic factor against complications. The antigen frequencies found were compared with: 1) Those in the general Caucasian reference population (9th Histocompatibility Workshop, 1984). The study group presented the HLA characteristics known to occur in insulin-dependent diabetes: increase in A30, B8, B18, D6, DR3, DR4, BfF1 and decrease in A3, B7, DR2. Furthermore an increase in the frequency of DRw53, DQw2 and DQw3 alleles was noted.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

Epitope mapping of HLA-B27 and HLA-B7 antigens by using intradomain recombinants.

To study the HLA-B7 and HLA-B27 antigenic determinants, hybrid genes between these two alleles were constructed by in vivo recombination in Escherichia coli. After transfection of these genes into P815 (high transfection efficiency recipient) murine cells, the bindings of Bw6, HLA-B7, and HLA-B27 allele-specific mAb were studied, as well as that of human anti-HLA-B7 and anti-HLA-B27 monospecific alloantisera. Most of the HLA-B7 antigenic determinants were assigned to the first external domain of the molecule. Four different epitopic areas could be defined: the Bw6 epitope was associated with residues 82 and 83; the BB7.1 epitope to amino acids 63, 67, and 70; the MB40.2 and MB40.3 epitope to amino acid sequence 177-180, and human alloantisera identified as an epitope associated with residue 9. HLA-B27 antigenicity studied by TM-1 mAb was found to involve residues 77 and 80 in the alpha-1 domain. Results obtained with human monospecific alloantisera allowed the definition of an additional allospecific site associated with the NH2 terminal part on the alpha-1 domain of HLA-B27. Epitope mapping fits with data obtained by sequence comparisons and is discussed with reference to the crystallographic three-dimensional structure of the HLA-A2 molecule.

Amino Acid Sequence↗
PubMed1988

HLA A,B,C and DR association with insulin-dependent diabetes in Martinique.

HLA-A,B,C, and DR frequencies have been determined in 34 Coloured Martinican IDDM patients to establish the HLA and IDDM associations. HLA A3, B15, B18, Cw3 and DR4 antigens associations with IDDM are confirmed by this study. We found an increase of B21 similar to that found in Asiatic Indians. As in some African Black populations and in Cape coloured people, A1, B8, and DR3 are not increased in our population. We should point out that our patients' ages of onset were low, and that some studies have found DR4 association in young patients and DR3 in older ones. The protective role of DR2 is confirmed here. B35 and Cw4 negative associations have been found. We have observed that the antigens associated with IDDM are decreased in our control population, except DR4, and that the negative associated DR/ and Cw4 antigens are increased compared to the Continental French population. This corresponds with the low IDDM incidence in Blacks and Coloured people.

Diabetes Mellitus, Type 1↗
PubMed1988

[Host-graft interactions after allogenic bone marrow transplantation; choice of donor].

The complexity of host-graft interactions after bone marrow transplantation explains the criteria of choice of the donor. Graft rejection, graft-versus-host disease, graft-versus-leukemia, delayed immune reconstitution, often associated or mutually exclusive are observed even with an HLA identical sibling donor. Syngeneic transplants may be complicated by leukemic relapse related to the loss of the graft-versus-leukemia effect. The compilation of files of unrelated donors increases the possibility of finding a matched unrelated donor. Preliminary results suggest that clinical results may be equivalent to those achieved with HLA identical sibling donors. Overall results of HLA mismatched transplants are disappointing because of the increase of immunological complications. Attempts at preventing graft-versus-host disease with T cell depletion led to an increase of immunological complications: rejection and leukemic relapse. Modifications of the conditioning regimen and use of in vivo monoclonal antibodies are currently being investigated. Ethical, legal, and psychological considerations have also to be taken into account in the donor choice especially with the increase of the donor pool.

Bone Marrow Transplantation↗
PubMed1987

Graft vs graft reaction resulting in the elimination of maternal cells in a SCID patient with maternofetal GVHd after an HLA identical bone marrow transplantation.

In a young girl with a severe combined immunodeficiency, the presence of circulating maternal T lymphocytes was proven by HLA typing. Manifestations of skin graft vs host disease were associated with the persistence of maternal cells. The patient received an HLA identical bone marrow transplantation from her brother without any conditioning. The bone marrow transplantation was quickly followed by a transient and dramatic increase in skin lesions associated with fever and the finding of a high number of circulating lymphocytes and eosinophils. Lymphocytes were shown to be of donor origin and exerted a spontaneous cytotoxic activity toward maternal cells. This activity progressively disappeared within 90 days, whereas maternal cells were no longer detected in patient's blood, and skin graft vs host disease was resolved within 8 wk. Cytotoxic activity was proven to be mediated by donor T lymphocytes specific for the mother's HLA antigens. The cytotoxic activity was demonstrated to be specific for the HLA class I molecules of the mother not shared with her daughter (HLA A1, B17) as shown by the use of a series of HLA typed cells as targets. In addition, cold K562 target cells did not block the cytotoxic activity, and the kinetics of the cytotoxic activity did not correlate with that of natural killer activity emergence after the bone marrow transplantation. Patient's serum did not contain antibodies toward maternal specific HLA class I antigen. Cytotoxic activity was totally blocked by anti-T3 monoclonal antibodies and partially by anti-T8 and anti-T4. It is thus likely that donor origin cytotoxic T lymphocytes were promptly activated after bone marrow transplantation and provoked the elimination of the maternal graft after a transient exacerbation of graft vs host disease manifestations. This observation represents one of the first examples of the possible role in vivo of allogeneic cytotoxic lymphocytes in humans.

Bone Marrow Transplantation↗
PubMed1987

HLA-A, B and DR antigen frequencies in patients with AIDS-related persistent generalized lymphadenopathy (PGL) and thrombocytopenia.

HLA-A, B, DR phenotype frequencies were studied in 69 homosexual patients with persistent generalized lymphadenopathy (PGL), in 8 patients with LAV/HTLV III related thrombocytopenic purpura and in 21 homosexual controls. Antigen DR5 was significantly increased in PGL patient groups as compared to controls. Our findings suggest that genetic factors associated with HLA-DR5 antigen may predispose individuals infected by the LAV/HTLV III virus to the occurrence of PGL and/or thrombocytopenia.

AIDS-Related Complex↗
PubMed1987

HLA typing in heavily transfused haemophiliacs with or without antibodies against human immunodeficiency virus (HIV).

HLA-A, B, DR antigens were determined in 46 patients, heavily transfused with blood products. Patients were 44 haemophiliacs, one case of afibrinogenemia and one case of von Willebrand's disease. Thirty-three patients had HIV antibodies. No significant difference for HLA antigen frequencies was observed in haemophiliacs with or without HIV antibodies, nor between haemophiliacs and a control population.

Adolescent↗
PubMed1987

[HLA A-B and DR in dilated myocardiopathies].

HLA A, B typing was performed in 90 patients (90 men, 10 women), and HLA DR typing in 49 patients with dilated cardiomyopathy in order to test the hypothesis that a particular genetic background may influence the immune response in that disease. No significant difference in phenotype frequency of the HLA A and B antigens was observed between patients and control population. In contrast, the HLA DR4 antigen was significantly more frequent among patients (40.8% vs 23.8%, p corrected less than 0.001). The results suggest that genetic factors play a role in the pathogenesis of dilated cardiomyopathy, and that since DR4 is frequently associated with auto-immune manifestations, a modified immune response is possible in dilated cardiomyopathy.

Adolescent↗