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Biomedical subjects

C Raffoux

Publications and source records attributed to C Raffoux.

At least 91 records · Page 5Linked to original sources

[Influence of the anti-HLA immunization profile before grafting on the outcome of renal transplant].

A retrospective study of HLA immunization profile before a first graft of unrelated kidney in 212 immunized recipients (with an initial peak greater than or equal to 25%) shows that one can define at least 3 groups of responder with a different graft outcome. Recipients with either weak or strong variance of HLA antibody (VP) before graft (group I: VP less than 230 and group III: VP greater than 830) have a significantly lower graft survival: 54% (p = 0.006) and 45% (p = 0.002) respectively at 4 years, than recipients of group II (230 less than VP less than 830) for whom the prognosis is of 77% after the same time period. If similar results are observed on independent series, VP would be of a great interest for the definition of a new classification of responders, and on a practical level for the choice of renal transplant.

Antibodies↗

[Setting-up a national file of bone marrow volunteer donors].

The lack of HLA matched sibling donors has become a problem. Recent improvements suggest the feasibility of marrow transplantation from unrelated donors. A program to obtain volunteer bone marrow donors has been developed. A total of 3,853 HLA A B typings were performed. A search for 83 patients was initiated; 51 of them had one or more HLA A and B (61%), 8 HLA A, B and DR antigen identical donors, 2 did not react in mixed lymphocyte culture. This experience confirms the necessity of increasing the donor file but the size remains to be established.

Bone Marrow Transplantation↗

[Study of the HLA-DQ system by the complement fixation test on lymphocytes stimulated by phytohemagglutinin. Existence of HLA-DQX allele(s)].

The complement fixation microtechnique against PHA blasts has been used to study HLA-DQw1, 2, 3 specificities with sera from multiple transfused patients and/or from multiparous women. Several sera (6 or 7) have been used to define each DQ specificity. The sera have been chosen because of their reactivity with cells from HLA-DR 1, 2 or w6 donors (for DQw1), DR3 or 7 donors (for DQw2,) DR4 or 5 donors (for DQw3). Correlation coefficients between DQ and DR specificities were from 0.56 to 0.91. Correlation coefficients between sera were from 0.51 to 0.92 in each cluster of sera. The segregation of DQw1, 2, 3 specificities has been studied in 46 families with 234 children. This study showed haplotypes lacking DQw1, 2, 3 specificities. The segregation of such 11 DQX haplotypes has been observed in 38 children from 8 families; 5 children were DQX/DQX homozygotes. Up to now, no serological reagent defining the specificity (or specificities) corresponding to DQX has been found. No preferential association was observed between DQX and DR specificities. The gene frequencies observed in 170 haplotypes in these 46 families were as follows: DQw1: 0.400; DQw2: 0.252; DQw3: 0.282; DQX: 0.065. Detecting DQ specificities seems easier by CF on PHA blasts than by lymphocytotoxicity microtechnique against B lymphocytes and monocytes from pheripheral blood. This suggests that PHA blasts express larger quantities of DQ molecules than B lymphocytes and monocytes. The results confirm that complement fixation microtechnique against PHA blasts is efficient for HLA-DQw typing.

Alleles↗

[HLA typing in patients with chronic adenopathies in a population at risk for AIDS].

HLA-A B and DR typing were performed in 77 patients with AIDS related complex (ARC)--69 lymphadenopathy associated syndrome and 8 thrombocytopenic purpura LAV/HTLV III related--and 21 symptom free homosexual males. A significant increase in the frequency of HLA DR5 antigen was observed in patients with ARC mainly in purpura thrombocytopenic patients. We suggest that increase of HLA DR5 antigen support the view that DR5 antigen could be one of the factors necessary at the spreading out clinical symptoms.

AIDS-Related Complex↗

Bone marrow transplantation for chronic granulocytic leukemia.

Thirty-seven patients with chronic granulocytic leukemia have been treated with supralethal chemoradiotherapy followed by transplantation of bone marrow from HLA-identical donors. All patients showed engraftment, and the Philadelphia chromosome (PH1) disappeared in each case. Four patients had syngeneic grafts before blast crisis and are still alive; 2 are in remission not maintained by therapy, and 2 others are receiving chemotherapy after having relapsed in the chronic phase. Thirty-three patients had allogeneic grafts; only 2 received the grafts during blast crisis, and neither is a long-term survivor. Of the 13 patients who had grafts in the accelerated phase, 6 died of complications related to the transplantation, and 1 died after a myeloblastic relapse. Thus 6 patients are in unmaintained remission with a median follow-up of 13 months. Eighteen patients received grafts in the chronic phase. All 10 survivors are in unmaintained remission with a median follow-up of 14 months; in this group, no patient has relapsed. The granulocytic hyperplasia of the chronic phase can be more effectively ablated than established blastic leukemia. The mortality rate of transplant-related complications must be weighted against the typical rate of progression of chronic granulocytic leukemia. Although a longer follow-up period is needed for full evaluation, bone marrow transplantation may now be offered to patients in the chronic phase in an attempt to achieve long-term survival or cure of more than one-half of these patients.

Adolescent↗

[Organ transplantation in France in 1984 (activity report of France-Transplant)].

Nine hundred and seventy four renal transplantations were performed in 1984, thus attaining a total 7927 grafts made in France at the end of 1984. The numbers of heart transplantations (77), to which 100 prospects in 1985 can be added, as well as liver grafts (13) plus 50 prospects in 1985, are showing a spectacular increase. Although the considerable improvement of heart graft and liver graft results can be attributed, essentially to the use of Cyclosporine, this trend can be dependent in the case of kidney transplantations also on transfusions before and on a better HLA-B DR compatibility which can in optimal situations represent a respective gain of 10% and 15% of graft survival.

Adult↗

[HLA and familial multiple sclerosis].

Some data suggest an environmental perhaps a viral factor but also of a genetic factor in the etiology of multiple sclerosis. Among the latter is the notably increased risk for a twin when the other twin has the disease, a risk further increased if they are monozygotic. There is also a greater than chance frequency of common HLA haplotypes in 2 affected siblings. The frequency of familial forms of multiple sclerosis is estimated at approximately 6 p. 100. We have studied 14 families of which 12 included 2 members with multiple sclerosis and 2 with 3 affected members. Parental relation between patients was parent to child (7 cases), brother to sister (5 cases), sister to sister including two pairs of twins (4 cases) and cousin to cousin on the mother's side (2 cases). When compared with non-familial multiple sclerosis there were no particular features in clinical disorders or course: 4 forms were progressive, the others evolving by episodes. In 26 patients in whom HLA antigens were determined, the DR2 antigen was present 19 times, the B7 antigen 9 times and the A3 antigen 7 times. In the 8 pairs of siblings with multiple sclerosis, 2 were HLA-identical and 5 semi-identical. One pair had no common haplotype. Grouping of HLA in 22 healthy members allowed 8 genealogic trees to be established. If a gene for susceptibility to multiple sclerosis exists, it is of low penetration, of dominant transmission and of limited frequency. It probably lies close to the region D of chromosome 6, because of the disequilibrium of crossed linking with A3, B7 and DR2 antigens.

Chromosome Mapping↗

Study of HLA antigens of the Martinican population.

This is the first time a study has been undertaken on the HLA profile of the Martinican population, a population which is essentially the product of intermixture between African-Negroes and French Caucasians. Two hundred and thirty-eight nonrelated subjects were typed for the A and B loci, 158 subjects for C locus and 128 for DR locus. After analysis of our parameters (antigen and gene frequencies, linkage disequilibria, etc.) and their comparison to those found in the Black and Caucasian control populations, we came to the conclusion that our racially-mixed population is closer to the African-Negro population than to the French Caucasian. A study of the average gene flow enabled us to evaluate the Caucasian contribution as being about 30%. This figure is subject to change inasmuch as racial intermixture continues. Socio-cultural variables are assumed to play a minimal role, given the high rate of illegitimacy.

Africa↗

HLA antigens and toxic reactions to sodium aurothiopropanol sulphonate and D-penicillamine in patients with rheumatoid arthritis.

One hundred and forty-one patients with rheumatoid arthritis treated with aurothiopropanol sulphonate or D-penicillamine, or both were examined for HLA antigens to investigate the genetic influence on the occurrence of different adverse reactions during therapy. All 13 patients possessing HLA-DR3 had toxic reactions. The relative risk for DR3 positives of developing skin eruptions or proteinuria was calculated to be 10.5 times and seven times respectively that of DR3 negatives. The incidence of DR7 antigen in 94 patients with toxic reactions was significantly decreased (11% compared with 28% in controls) suggesting a protective role for this antigen.

Adult↗

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↗

[Role of transfusions and significance of HLA-A, B and DR compatibility in renal transplants].

The results study of renal allograft performed in the France-Transplant network, shows the beneficial effect of blood transfusions on graft survival; their immuno-suppressive effect allowed the tolerance of the transplant, despite of the presence, at times, of incompatibilities HLA. In this work, we have studied the effect of HLA-A, B, DR incompatibilities in 803 unrelated recipients according to their preimmunized status. In the 303 presensitized patients (by transfusion or transplantation) we show clearly the strong effect of the HLA compatibility and the additive effect of the three loci A, B, DR (94% of graft survival at two years for the best matched v.s. 36% for the worst). In the 500 non responder patients, there is no effect of the compatibility A, B, DR (69% for the best matched v.s. 71% for the worst). Presensitized patients reach currently 50% of the waiting list of dialysed. Cooperative efforts should avoid heavily mismatched transplants in case of preimmunization.

Actuarial Analysis↗

Exclusion of a tight linkage between familial polyposis coli and HLA.

Linkage was investigated between a dominant gene determining familial polyposis coli (FPC) and HLA in a large pedigree. A tight linkage was excluded at a value of the recombination fraction between 0 and 5%. Linkage studies with various markers should be pursued to permit detection of high risk individuals and to better understand the phenotypic variability observed in certain polyposis families.

Colonic Neoplasms↗