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Biomedical subjects

D A Savage

Publications and source records attributed to D A Savage.

14 recordsLinked to original sources
PubMed1992

HLA class II frequencies in celiac disease patients in the west of Ireland.

Restriction fragment length polymorphism analysis, using a single restriction enzyme TaqI-multiple-probe system for HLA-DRB1-DQB1 and -DQA1, was used to determine HLA-DR and -DQ frequencies in 56 unrelated celiac patients and 47 unrelated controls from the west of Ireland. In addition, HLA-DPB1 allelic frequencies were determined in the same group of patients and controls by using the technique of enzymatic DNA amplification of the polymorphic second exon of HLA-DPB1 genes in conjunction with sequence-specific oligonucleotide probing. The results suggest that HLA-DQ rather than HLA-DR is more important in conferring susceptibility to celiac disease. Furthermore, no association between HLA-DP and celiac disease was found in this study.

Adolescent↗
PubMed1992

Frequency of HLA-DPB1 alleles, including a novel DPB1 sequence, in the Northern Ireland population.

HLA-DPB1 allele frequencies in 150 unrelated normal individuals from Northern Ireland were determined using oligonucleotide typing methods. HLA-DPB1*0401 was the most common allele in the population possessed by 75.3% of subjects, followed by DPB1*0201 (20.7%). In addition to these alleles, only HLA-DPB1*0402, -DPB1*0301, and -DPB1*0501 were present in subjects at frequencies greater than 10%. The results in this study are in broad agreement with other Caucasoid studies, but there is regional and ethnic variation in HLA-DP allele frequencies. Three DPB1 alleles were found to be in linkage disequilibrium with HLA-DR antigens determined by RFLP, namely, DPB1*0101 with DRw17 (Dw24 associated) RFLP, DPB1*0501 with DRw13-Dw19 RFLP, and DPB1*1901 with DRw13-Dw18 (Dw25 associated) RFLP. One individual revealed a novel DPB1 pattern of probe reactivity, which following DNA sequencing was found to be HLA-DPB1*2001. To assess the system used and to compare consistency of results between laboratories, 62 cell lines were oligotyped for HLA-DP. The results revealed the system described here to be extremely accurate and showed excellent agreement of HLA-DP typing results for cell lines between laboratories.

Alleles↗
PubMed1991

Five new TaqI DRB1 polymorphisms.

Five new restriction fragment length polymorphisms (RFLPs) using TaqI and a DR beta probe have been found in Caucasian individuals. The families of these individuals have been tissue typed by serological and RFLP methods. The new RFLPs are similar to previously established RFLPs except for the size of one fragment in each instance.

Blood Donors↗
PubMed1991

HLA-DR and DQ DNA genotyping in multiple sclerosis patients in Northern Ireland.

DNA from multiple sclerosis (MS) patients and healthy control individuals from the Northern Ireland population, was assessed by restriction fragment length polymorphism (RFLP) analysis to look for disease-associated polymorphisms. HLA-DR and -DQ allogenotyping was performed using a single enzyme (TaqI)/Multiple probe system. The TaqI/DR beta RFLPs correlate well with serologically defined specificities and in addition detect further subtypes of these associated with DQ or Dw specificities. The results confirm an association of MS with DR beta 15 and show a decreased frequency of DR beta 4 in the patients. An increased frequency of DR beta 17 in patients negative for DR beta 15 was also found. There is a decrease in the frequency of the TaqI/DQ beta 3 (TA10 + ve) RFLP and the TaqI/DQ alpha 2LL genotype in the MS patients, these not being associated with DR beta 15. In addition RFLP analysis of the DPA1 and DPB1 genes reveals an MspI/DP beta 3.0-kb fragment which occurs at a higher frequency in the patients than in the controls.

Gene Frequency↗
PubMed1991

HLA antigen frequencies and Wegener's granulomatosis.

Previous reports of an association between HLA tissue type and Wegener's granulomatosis are contradictory. By using for the first time a highly sensitive restriction fragment-length polymorphism (RFLP) analysis in addition to standard microcytotoxicity assays, the largest series yet investigated (41 patients) was tissue typed. No association was found between any specific HLA antigen and Wegener's granulomatosis. Although the condition appears to be immunologically mediated, this study indicates that the HLA antigens do not have a major role.

Adolescent↗
PubMed1990

Frequency and associations of HLA class II TaqI allogenotypes in the Northern Ireland population.

HLA-DR allogenotyping was performed on a panel of 1019 Caucasian individuals from the Northern Ireland population, of whom 150 were also HLA-DQ allogenotyped, using a single enzyme (TaqI)/multiple probe system. TaqI/DR beta restriction fragment length polymorphisms correlate well with the serologically defined specificities and in addition detect further subtypes of these associated with DQ or Dw specificities. The most frequent DR beta allogenotypes were DR beta 15, DR beta 4, and DR beta 17 (Dw24). The frequency of the subtypes of DR beta 4 associated with DQ beta 3 (TA10+) was higher than that reported elsewhere for Caucasian populations, whereas the frequency of the subtypes of DR4 beta associated with DQ beta 3(TA10-) was subsequently reduced. The subtypes of DR beta 4 associated with DQ beta 3 (TA10+) were strongly associated with B44. The TaqI/DX alpha gene polymorphisms, as revealed by the DQ alpha cDNA probe, were found to be associated with DR beta allogenotypes.

Blood Donors↗
PubMed1988

Discrepancies in serological tissue typing revealed by DNA techniques.

DNA techniques were applied to typing a population of renal patients in order to assess the number of discrepancies between this technique and the serological technique. Five patients had been given an incorrect type by serology, and in 22 instances allogenotypes were found where previously there had been a serological blank. DNA typing was also able to determine allogenotypic subtypes that correlated with DR antigens difficult to split by serology and to determine allogenotypic subtypes correlating with DR antigens not known to have a split by serology. Whereas DNA typing provided a result first time of testing on all but 3 patients, the average number of serological testings for each patient was 1.9.

DNA↗
PubMed1988

A DNA-RFLP typing system that positively identifies serologically well-defined and ill-defined HLA-DR and DQ alleles, including DRw10.

A single enzyme/multiple probe system of HLA-DR and DQ typing using restriction fragment-length polymorphism (RFLP) analysis is presented. TaqI-digested genomic DNAs are hybridized sequentially with short DR beta, DQ beta, and DQ alpha cDNA probes. The DR beta probe discriminates between the DR allelic specificities DR1 to DRw14, with the two exceptions of some DR3/DRw13 and some DR7/DRw9 combinations. We describe the positive identification of a DRw10-specific RFLP and demonstrate its segregation in families. The DQ beta probe defines an allelic system that identifies the alleles DQw1, DQw2, and DQw3. This permits the resolution of DR3/DRw13 and DR7/DRw9 alleles by defining the DR/DQ association caused by linkage disequilibrium. The DQ alpha probe defines another allelic series interrelated with, but independent from, the DQ beta series. Specific DQ beta/DQ alpha RFLP combinations correlate with known Dw splits of DR2, DRw6, and DR7. Combined use of the three probes permits the identification of HLA-DR, DQ, and certain Dw specificities and provides an effective and easily interpretable system for major histocompatibility complex class II allogenotyping.

Alleles↗
PubMed1988

Identification of HLA-DRw52 associated antigens using HLA class II allogenotyping.

The HLA-DR antigens DRw8, DRw11, DRw12, DRw13, DRw14 and DRw17 are strongly associated with the supertypic specificity DRw52. This association has been used to assist in assignment of serological specificity. However, difficulties in the identification of these antigens arise since they are serologically crossreactive. This report describes the application of restriction fragment length polymorphism (RFLP) allogenotyping to assist in the positive identification of DRw8, DRw11, DRw12, DRw13, DRw14, DRw17, DRw52a and DRw52b, and in addition describes further subtypes defined by RFLP which correlate with DQ or Dw associations. We also describe a novel TaqI/DR beta RFLP in a Caucasian family which types serologically as DRw12.

DNA↗