Search PubMed⌕ Search

Biomedical subjects

M Busson

Publications and source records attributed to M Busson.

At least 37 records · Page 2Linked to original sources
PubMed2001

HLA class I and class II are both associated with the genetic predisposition to primary Sjögren syndrome.

Primary Sjögren syndrome (pSS) is an autoimmune disease characterized by progressive destruction of the exocrine glands leading to mucosal and conjunctival dryness. It is marked by lymphocytic infiltration of the glands and the accumulation of several types of autoantibodies such as rheumatoid factor (RF), antinuclear, anti-SS-A (anti-Ro) and anti-SS-B (anti-LA) autoantibodies. The susceptibility to pSS and/or the presence of SS-A/SS-B autoantibodies in pSS patients is associated with DRB1*03-DQB1*02 and DRB1*02-DQB1*06 haplotypes, whereas no associations have been described with any HLA class I allele. To define the impact of HLA class I alleles in predisposition to pSS, 46 patients responding to the European criteria and 222 healthy unrelated Caucasians were analyzed for their HLA class I and class II haplotypes. Our results confirm the association of the DRB1*03-DQB1*02 haplotype with SS-A/SS-B autoantibodies positive pSS and demonstrate a significant association of the HLA-A24 with the disease. Moreover, HLA-A24 is more often associated with DRB1*11-DQB1*0301 and/or DRB1*0301-DQB1*02 in pSS patients than in the controls. The novel association of HLA class I alleles with susceptibility to pSS provides new insights to the genetic predisposition to this disease and subsequently to its physiopathology.

Adult↗
PubMed2001

Genomic diversity of natural killer cell receptor genes in three populations.

We report the distribution of genes encoding 11 killer cell immunoglobulin-like receptors (KIR) and 2 CD94:NKG2 receptors, in 32 Caucasians, 67 Australian Aborigines and 59 Vietnamese. The inhibitory and the activating KIR genes were found at different frequency in the three populations. No correlation was found between the polymorphism of the KIR genes and the HLA specificities of the tested samples. The most significant KIR associations were 2DL2 with 2DS2; 2DL2 with 2DS3 and 3DL1 with 2DS4 in all three study groups. In Caucasians and Vietnamese 2DS2 was associated with 2DS3 and 2DS1with 3DS1. KIR 2DL1 was strongly associated with three other KIRs: 2DL3, 3DL1 and 2DS4 in Aborigines. The distribution of the KIR phenotypes was different in the three populations. The AA1 phenotype was frequent in Vietnamese (42.4%) and Caucasians (31.2%), but very rare in Aborigines (1.5%). In contrast, the BB7 phenotype was very common for Aborigines (22.4%) and was absent in the two other groups. Our data demonstrate that different associations and putative KIR haplotypes could be distinguished in different populations.

Gene Frequency↗
PubMed2001

Multicenter trial of one HLA-DR-matched or mismatched blood transfusion prior to cadaveric renal transplantation.

BACKGROUND: The beneficial effect of blood transfusions before cadaveric renal transplantation on allograft survival, although previously well documented, has become controversial in light of their adverse effects. Recently, it has been suggested that their clinical benefits are due to HLA-DR sharing between the blood donor and recipient. METHODS: In this prospective study, 144 naive patients were randomly assigned to receive one unit of blood matched for one-HLA-DR antigen (N = 49), or one unit of mismatched blood (N = 48), or to remain untransfused (N = 47). Graft survival and acute rejection rate were analyzed in 106 cadaveric renal allograft recipients receiving the same immunosuppressive protocol. RESULTS: Graft survival was similar in the three groups at one and five years: 91.7 and 80% in untransfused patients, 90.3 and 79.3% in patients transfused with one DR-antigen-matched unit, and 92.3 and 83.7% in patients transfused with HLA-mismatched blood. The difference in the incidence of six-month post-transplant acute rejections was not statistically significant in the three groups: 12 out of 36, 33.3% in nontransfused patients; 6 out of 31, 19.4% in patients transfused with one DR-matched blood; and 13 out of 39, 33.3% in patients transfused with mismatched blood. CONCLUSION: The results of our prospective randomized trial showed that in a population of naive patients, one transfusion mismatched or matched for one HLA-DR antigen given prior to renal transplantation had no significant effect on the incidence and severity of acute rejection, and did not influence overall long-term graft outcome. Considering the potentially deleterious adverse effects of blood transfusions, the costs, and the considerable logistical efforts required to select and type blood donors, such a procedure cannot be recommended in a routine practice for patients awaiting cadaveric kidney transplantation.

Acute Disease↗
PubMed2000

CALM-AF10 fusion gene in leukemias: simple and inversion-associated translocation (10;11).

A translocation (10;11)(p12;q14) was observed in two children, one with acute eosinophilic leukemia and the other with acute T-cell lymphoblastic leukemia. The presence of CALM-AF10 fusion was ascertained by reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. Fluorescence in situ hybridization (FISH) analysis showed that AF10 gene splitting was associated with partial inversion of chromosome 11 in the first patient. In addition, FISH analysis also determined the orientation of the CALM gene, 5' telomere to 3' centromere on 11q.

Adolescent↗
PubMed2000

HLA-DR restricted peptide candidates for bee venom immunotherapy.

T cell epitopes containing peptides have been recently proposed as an alternative to conventional immunotherapy of allergic diseases because they are expected to be better tolerated than allergen extracts. A principal limitation to their clinical use is that they present an important diversity, which primarily results from the polymorphism of HLA class II molecules. In Caucasian populations, however, seven alleles of the most expressed molecules (namely DRB1*0101, DRB1*0301, DRB1*0401, DRB1*0701, DRB1*1101, DRB1*1301, and DRB1*1501) predominate. Peptides from allergens that would efficiently bind to them should be potential candidates for specific immunotherapy. In this paper, we have determined the peptides present in the major bee venom allergen by investigating the capacity of synthetic peptides that encompass its whole sequence to bind to each allele. Several efficient binders have been identified and are either allele-specific or common to several HLA-DR molecules. Interestingly enough, the 81-97 sequence is universal in the sense that it binds to all studied molecules. This sequence is surrounded by several active regions, which make the 76-106 sequence particularly rich of binding determinants and a good candidate for specific immunotherapy. Statistical analyses of the binding data also provide an overview of the preponderant HLA-DR alleles specificity.

Alleles↗
PubMed2000

HLA class II polymorphism contributes to specify desmoglein derived peptides in pemphigus vulgaris and pemphigus foliaceus.

Susceptibility to Pemphigus, an autoimmune disease of the skin, has been previously linked to DRB1*0402, 1401/04 and DQB1*0503 in pemphigus vulgaris (PV), to DRB1*0102, 0404, 1402/06 in endemic pemphigus foliaceus in Brazil and to DRB1*04 in Italian patients suffering from pemphigus foliaceus (PF). The disease is caused by autoantibodies against desmoglein (Dsg1 in PF, Dsg3 in PV). Molecular typing of 57 French patients suffering from PV (37) and from PF (20) confirmed previous results concerning PV and showed that DRB1*0102 and 0404 are susceptible molecules to PF in France. We have analysed the characteristics of the 'pockets' of the susceptibility-associated molecules to PV and PF and we showed that (i) in PV, two kinds of Dsg3 derived peptides may be presented by HLA-DR according to HLA polymorphism (DRB1*0402 or DRB1*14/0406), (ii) the same Dsg1 peptides may be presented by DRB1*0102, DQB1*0404 or DRB1*14 in PF, (iii) the DRB1*14/0406 PV-related molecules may be able to present Dsg1 and Dsg3 peptides thereby providing an explanation for the cases of PV with combined responses to Dsg1 and to Dsg3 which are typified by a muco-cutaneous clinical phenotype.

Alleles↗
PubMed2000

A linkage disequilibrium map of the MHC region based on the analysis of 14 loci haplotypes in 50 French families.

A sample of 100 individuals from 50 French families of known pedigrees were typed for 14 loci of the HLA region (DPB1, DQB1, DQA1, DRB1, DRB3, 4, 5, C4B, C4A, Bf, C2, TNFa, TNFb, B, Cw, A). Linkage disequilibrium in each pair of loci was investigated by an exact test using a Markov chain algorithm. The results indicate no disequilibrium between DPB1 and the other loci, whereas the other class II genes are all significantly linked to each other. Linkage disequilibrium is also detected between some pairs of class I and class II-class I loci despite the long physical distance separating the loci (e.g. A-B, Cw-DRB1). On the other hand, some contiguous loci of the class III region are found to be in equilibrium with each other. Several hypotheses including selection, but also unequal allelic diversity at different MHC loci are discussed to explain this complex pattern of linkage disequilibrium.

Chromosome Mapping↗
PubMed1999

Genetics and specific immune response in allergy to birch pollen and food: evidence of a strong, positive association between atopy and the HLA class II allele HLA-DR7.

BACKGROUND: In some geographic areas birch pollen represents the most prominent cause for airborne allergic diseases. Up to 70% of patients allergic to birch pollen are hypersensitive to fruits, especially apples. Associations have been found, in some instances, with a sensitivity to aeroallergens and HLA class II genes. OBJECTIVES: We investigated whether susceptibility or resistance to birch pollen allergy with and without food allergy was associated with HLA class II genes. METHODS: Blood samples were obtained from 2 groups of unrelated European-born white adults: 42 atopic patients (31 of them with asthma) and 42 healthy control subjects with no personal or familial history of asthma or atopy. Their antibody responses to birch pollen, apples, grass, and weed pollens were evaluated by skin tests, RASTs, and immunoprints. Genomic DNA was extracted from PBLs. The exons of DQA1, DQB1, DRB1, and DPB1 genes were selectively amplified by using the PCR method. Genotyping was carried out by digestion of the amplified DNA products with allele-specific endonucleases (PCR-RFLP), which recognize allelic variations in the polymorphic exon. RESULTS: We found no significant differences in the frequency of DPB1 alleles between patients and control subjects. HLA class II DR4 and/or DR7 alleles were present in 42.6% of the patients and in only 2.4% of the healthy subjects. These results confirm a previous study of a group of polysensitized atopic patients, which showed that DR4 and DR7 alleles were rare in healthy control subjects and frequently observed in atopic subjects with or without concomitant asthma. CONCLUSION: We conclude that the allele HLA-DR7 is significantly involved in the presentation of apple and pollen allergens. However, we suggest that this susceptibility is more related to atopy than to specific responses to allergens.

Adult↗
PubMed1999

HLA DRB1, DMA, and DMB gene polymorphisms in rheumatoid arthritis.

OBJECTIVE: To study the influence of DMA and DMB genes on susceptibility to Rheumatoid Arthritis (RA). METHODS: HLA-DRB1, DMA and DMB polymorphisms were defined by PCR SSOP in 203 European Mediterranean RA patients and 181 unrelated healthy controls. RESULTS: No significant difference in the phenotype frequencies of DMA and DMB alleles was observed between patients and controls. We found decreased frequencies of DMA*0102 and DMB*0104 in patients but this did not reach significance. These decreased frequencies could be due to a positive linkage disequilibrium with DRB1*0701, an allele which is underrepresented in RA patients. In stratified analysis with RA susceptibility Epitope positive (SE) DRB1 alleles, there was no significant difference in DMA and DMB phenotype frequencies between SE/SE, SE/X, and X/X patients versus controls. Among SE/X subjects, no significant difference in DM distribution frequencies was observed in DRB1*0101/X, 0102/X, 0401/X, 0404/X and 0405/X groups. CONCLUSION: DMA and DMB polymorphism does not seem to influence susceptibility to develop RA. Differences in DMA phenotype frequencies between patients and controls are secondary to linkage disequilibrium with DRB1 alleles.

Adult↗
PubMed1999

Analysis of hsp70 gene polymorphism in allergic asthma.

BACKGROUND: Allergic asthma is a multifactorial and probably multigenic inflammatory disease of the upper airways, and has been associated with the HLA class II alleles DR4 and DR7. Here we investigated possible associations with other polymorphic susceptibility/resistance genes located within the major histocompatibility complex, i.e., the genes coding the major 70-kDa heat-shock proteins (HSP; Hsp70) hsp70-1, hsp70-2, and hsp70-HOM, whose products are overexpressed in the bronchi of asthmatic patients. METHODS: Genomic DNA was extracted from peripheral blood lymphocytes or buccal epithelial cells of 48 patients with allergic asthma and 31 selected nonatopic control subjects, in whom we previously reported a strong association of atopy with DR4/DR7 alleles. RESULTS: No evidence was found for an independent role of hsp70 gene polymorphism in susceptibility to allergic asthma. However, hsp70 alleles might be involved in extended haplotypes of HLA markers. CONCLUSIONS: Our data suggest that Hsp70 overexpression in asthma results from complex interactions between environmental exposures and genetic background rather than from specific genetic variations in hsp70 genes.

Adult↗
PubMed1999

A new predictive model for insulin-dependent diabetes mellitus susceptibility based on combinations of molecular HLA-DRB1 and HLA-DQB1 pockets.

With a view to establishing an accurate evaluation of the genetic predisposition to insulin-dependent type I diabetes (IDDM), we have built a model based on the characteristics of the relevant pockets of HLA-DR and -DQ molecules. Three independent populations were investigated. Group I and group II were Caucasoids, while group III was Japanese, including a total of 1,166 IDDM patients and 2,391 healthy controls. We formulate the hypothesis that suceptibility to IDDM is not only explained by the absence of Aspartate 57 (negative charge) from pocket 9 of DQB1 (P9DQ), but also by the presence of an electric charge (+/- vs. neutral), generated by residues 70, 71 and 74 in pockets 4 of DRB1 (P4DR) and DQB1 (P4DQ) molecules. The respective weight of each pocket, was evaluated in a multivariate analysis based on the logistic regression method. The 4 components (2 loci and 2 pockets) were systematically analysed in the computer model. It was clearly shown that the structural characteristics of pockets P9DQ-P4DR and, to a lesser degree that of P4DQ, account for IDDM predisposition. On applying the model to the whole international series, it appears that the highest risk concerns individuals with P9DQ non-Asp 57 and both the charged P4 of DRB1 and P4 of DQB1, conferring a 80% prediction of susceptibility. Conversely, P9DQ Asp and neutral P4DR and P4DQ give the lowest risk with a predictive value of 5%. This model of risk susceptibility prediction fits remarkably well with the observed distribution in a worldwide study. It allows a better evaluation of the respective role of HLA-DR and -DQ molecules as a major component of susceptibility to IDDM.

Alleles↗
PubMed1999

[HLA-C allele recognition using DNA sequencing].

The HLA-C locus was sequenced in 106 normal unrelated members of the French CEPH families. Following generic PCR amplification, exons 2 and 3 were amplified separately then sequenced using the ALF Expres sequencer. The Sequi Typer program was used for data analysis. Of the 72 alleles identified to date, 20 were recognized in the panel studied. Results were compared to those provided by the lymphocytotoxicity test, which had a 13.5% error rate and failed to reach the level of specific recognition. Sequencing preceded by amplification allowed immediate unambiguous allele assignment in 96% of cases. In four cases, a complementary method was required to resolve ambiguities. Reproducibility was high. The sequencing strategy described herein is a significant advance and may be particularly valuable for achieving perfect donor/recipient matching for allogeneic stem cell transplants.

Alleles↗
PubMed1998

Mitochondrial DNA sequence variation in human leukemic cells.

The Long PCR followed by the RFLP technique has been used to search for abnormally structured mitochondrial DNA (mtDNA) and specific sequence differences implicated in the pathogenesis of acute lymphoblastic leukaemia (ALL). We have studied 54 specific sites whose combinations define groups of mtDNA types, in 30 leukemic patients of French Caucasian origin. Results were compared with those in 100 French healthy individuals. Nucleotide substitutions have been defined in 11 patients. This polymorphism is expressed by single base substitution at 6 sites which corresponds to 5 morphs, 2 of which were not found in the reference group. Combining the 11 observed morphs, we have identified 7 different mtDNA types, defined in 30 patients with ALL. Two of the morphs (MspI-2 and AvaII-3) and 3 of the types (17-2, 55-2, NewFr150) were not found in the group of healthy individuals. We have observed significant statistical changes in type 28-2 in ALL patients compared with the controls.

Adult↗
PubMed1998

T-cell recognition of mycobacterial GroES peptides in Thai leprosy patients and contacts.

We report here the mapping of T-cell-stimulatory determinants of the GroES 10-kDa heat shock protein homologues from Mycobacterium leprae and Mycobacterium tuberculosis, which are known as major immunogens in mycobacterial infections. Peripheral blood mononuclear cells (PBMC) from treated tuberculoid leprosy or lepromatous leprosy patients and from healthy household or hospital staff contacts of the patients were cultured with 20 16-mer peptides covering the entire sequences of both M. leprae and M. tuberculosis GroES. The total number of recognized peptides was found to be the largest in family contacts, while responder frequencies to the individual tested peptides varied (5 to 80%) with specificity between the patient and contact groups. Proliferative responses to some peptides showed positive or negative associations of low statistical significance with DR and DQ alleles, though responses to most GroES peptides were genetically permissive. Notably, the sequence of the 25-40 peptide of M. leprae, but not that of M. tuberculosis, was more frequently stimulatory in tuberculoid leprosy patients than in either group of sensitized healthy contacts. This peptide bound to a number of HLA-DR molecules, of which HLA-DRB5*0101 had the strongest affinity. The epitope core binding to this allele was localized to the 29-to-37 sequence, and its key residue was localized to the M. leprae-specific glutamic acid at position 32. This epitope may be of interest for the development of a blood test- or skin test-based diagnostic reagent for tuberculoid leprosy, subject to further clinical evaluation in untreated patients.

Amino Acid Sequence↗
PubMed1997

Maintenance cyclosporin monotherapy after renal transplantation--clinical predictors of long-term outcome.

BACKGROUND: There is considerable debate about whether maintenance cyclosporin (CsA) monotherapy is advisable or not in renal transplantation. METHODS: Between August 1984 and December 1989, 463 adult patients received a first cadaver graft. Initial immunosuppression was sequential: antilymphocyte or antithymocyte globulins (10-14 days), prednisone and azathioprine were combined and CsA was introduced (6-8 mg/kg/day) when the antilymphocyte or antithymocyte globulins were discontinued. When the graft function was stable and the peak of preformed lymphocytotoxic antibodies was < or = 25% and/or the number of rejection episodes was < or = 1, the steroid therapy was stopped within 1.5-3 months after transplantation, and azathioprine within 3-12 months. Patients with both anti HLA antibodies > 25% and more than one rejection episode were excluded. Cyclosporin doses were adapted for whole-blood trough levels between 100 and 200 ng/ml (monoclonal antibody radioimmunoassay or high-performance liquid chromatography). Cyclosporin monotherapy was attempted in 234 of the 463 patients. RESULTS: At the end of the investigation in January 1993 (follow-up time > 36 months, mean 60.5 +/- 4.5 months), 135 patients were receiving CsA without steroids or azathioprine. The 99 CsA monotherapy failures were due to rejection episodes in 48 cases, CsA A nephrotoxicity in 26 cases, and other causes in 25 cases, including five deaths and four with poor compliance. Renal function was stable in patients with successful CsA monotherapy: mean creatininaemia was 124 +/- 10 mumol/l at the time of CsA monotherapy inclusion and 129 +/- 10 mumol/l at the end of follow-up (mean time of CsA monotherapy 52 +/- 6 months). The parameters for predicting monotherapy success were age (43.2 versus 37.8. P = 0.0014), timing of trial inclusion > or = 6 months post-transplant (7.9 +/- 3 versus 5.3 +/- 3.1 months, P = 0.04), and excellent and stable renal function at the time of inclusion (124 +/- 10 versus 145 +/- 32 mumol/l, P < 0.001). CONCLUSIONS: Maintenance CsA monotherapy was effective in 58% of low-immunological-risk first-graft patients and probably did not jeopardize overall results of our first grafts: patient and graft survival were respectively 90 and 73% at 6 years. We propose this policy to avoid long-term complications of glucocorticoid and azathioprine in selected compliant recipients with low immunological risk, follow-up time post-transplantation > 6 months, and stable creatininaemia levels.

Adult↗
PubMed1997

Is matching for sex and age beneficial to kidney graft survival? Société Française de Transplantation and Association France Transplant.

A total of 6889 cadaver kidney grafts carried out in the French transplant network from 1 January 1989 to 31 December 1992 were analyzed using single and multifactorial methods in order to evaluate the impact on graft survival of matching for sex and age between donors and recipients. The mean graft survival rate was 75% at 3 yr with donors between 10 and 50 yr of age compared to 65% for donors under 10 yr of age and 67% at 3 yr for donors over 50 yr of age (p < 0.000001). For child recipients there were no significant differences in graft survival whatever the difference in age with the donor (+/- 10 yr). For young adults (17-49 yr of age) the prognosis at 3 yr was the same (75%) whether the donor was in the same age category or older than the recipient. For older adults (> 50 yr of age) a poorer prognosis was obtained when the donor was 10 yr or more older than the recipient (61% at 1 yr, p = 10(-4)). The grafts performed with male donors had a better prognosis (76% at 3 yr) than those using female donors (71% at 3 yr, p < 0.0002). The poorest results were obtained with female donors when the recipient was male (70% at 3 yr). The results of the multivariate analysis of seven parameters involved in graft survival show that the main parameters significantly controlling graft survival are preimmunization before the graft (p = 10(-6)), HLA-DR incompatibility (p = 0.004), retransplantation (p = 0.008), donor sex (p = 0.003), and matching for age between donor and recipient (p = 0.1). These results suggest that age and sex should be considered as criteria in the choice of donors and recipients in organ allocation.

Adolescent↗
PubMed1996

Diabetes mellitus after renal transplantation: characteristics, outcome, and risk factors.

The incidence and risk factors of posttransplant diabetes mellitus were evaluated in 1325 consecutive renal transplant recipients. Thirty-three (2.5%) patients developed diabetes mellitus requiring insulin therapy. Onset occurred a mean of 5.7 +/- 1.5 months following transplantation. The patients were compared with 33 paired-control kidney recipients. The patients were significantly older than the controls (46.8 +/- 1.9 vs. 40.6 +/- 2.1 years) (P<0.05), and chronic renal failure was more often related to interstitial nephritis (P<0.05). A family history of diabetes mellitus, the body mass index, ethnic origin, HLA phenotype, and the total doses of steroids and cyclosporine were similar in the two groups. The number of patients with at least one rejection episode was significantly higher among the diabetic patients (21 versus 9) but the number of episodes was similar. Diabetes occurred a mean of 1.1 +/- 0.3 months following rejection treatment. Intravenous pulsed prednisolone was always used for anti-rejection therapy. Insulin was withdrawn in 16 cases after a mean of 4 +/- 1 months, independently of steroid dosage reductions. Actuarial patient and graft survival rates were not significantly different, although 6-year outcome tended to be better in the controls (86% versus 93% for patient survival and 67% versus 93% for graft survival). This study suggests that pulsed steroid therapy might be the critical factor in the onset of posttransplant diabetes and that the risk is increased in older patients with chronic interstitial nephrititis.

Adult↗