Identification of two novel HLA-DRB1 alleles, HLA-DRB1*1214 and HLA-DRB1*1215, in two Taiwanese individuals.

Two novel HLA-DRB1 alleles, HLA-DRB1*1214 and HLA-DRB1*1215, were found in Taiwan using sequence-based typing method. DRB1*1214 differs from DRB1*120101 by two nucleotide substitutions on exon 2, causing amino acid changes at codon 37 (L-->F) and codon 38 (L-->V). We suggest that DRB1*1214 is the product of a gene conversion between DRB1*120101 and DRB1*140101 or DRB1*1405 and that HLA-DRB1*1215 differs from DRB1*120201 by one single nucleotide transition at exon 2, thereby causing amino acid change at codon 37 (L-->F).

HLA-DQB1*0317 is a novel allele with an unusual DR-DQ haplotype.

HLA-DQB1*0317 may have arisen by gene conversion from the DQB1*030302 backbone, leading to one amino acid change from Leu to Gly at codon 26.

Cytokine gene polymorphisms in Taiwan.

Cytokine gene polymorphisms may affect their transcription, influence their level of production, and may be implicated in inducing susceptibility or resistance to diseases. Cytokine single-nucleotide polymorphisms (SNPs) were used to determine allelic and genotypic frequencies in the Minnan, the Hakka, and in four indigenous tribes: the Ami, the Tsou, the Atayal, and the Tao (or Yami). The following cytokine gene polymorphisms were analyzed: interleukin-1alpha (IL-1alpha) (T/C -889), IL-1beta (C/T -511, T/C +3962), IL-1R (C/T Pst-I 1970), IL-1Ralpha (T/C Mspa1-I 1100), IL-2 (T/G -330, G/T +166), IL-4 (T/G -1098, T/C -590, T/C -33), IL-4Ralpha (G/A +1902), IL-6 (G/C -174, G/A nt565), IL-10 (G/A -1082, C/T -819, C/A -592), IL-12 (C/A -1188), interferon-gamma (A/T UTR 5644), transforming growth factor-beta (C/T codon 10, G/C codon 25), and TNF-alpha (G/A -308, G/A -238). Little differences were observed between the Minnan and the Hakka. On the other hand, the Minnan and Hakka showed significant differences with the indigenous people.

Two novel HLA-DRB1 alleles identified using a sequence-based typing: HLA-DRB1*1443 and HLA-DRB1*1351*.

Two novel HLA-DRB1 alleles, DRB1*1443 and DRB1*1351, were identified using a sequence-based typing protocol. DRB1*1443 differed from DRB1*140501 by one single-nucleotide substitution in exon-2 (codon 77, ACC-->GCC), which corresponded to an amino acid change of threonine to alanine. DRB1*1351 was identical to DRB1*1301 but differed by a single-nucleotide substitution at codon 50 (GTG-->TTG), resulting in an amino acid change of valine to leucine. Both new alleles present unique polymorphisms, which have not been seen among other DRB1 alleles and which have no known effect on peptide binding.

PCR-RFLP typing detects new HLA-DRB1 alleles: DRB1*13022, DRB1*1336 and DRB1*1435.

It is difficult to resolve all heterozygous combinations of the HLA-DRB1*03, *08, *11, *12, *13 and *14 allele group in a one-step generic HLA-DRB1 typing system. Therefore, it is common to employ a secondary technique utilizing group-specific primers to amplify this group of alleles separately from the other HLA-DRB1, -DRB3, -DRB4 and -DRB5 alleles. This paper describes a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method for broad typing of the HLA-DRB1*03, *08, *11, *12, *13 and *14 alleles which, as well as being time-efficient and cost-effective, has so far allowed the detection of 10 new alleles. The new alleles were identified after following up unusual or novel PCR-RFLP patterns. Of the 10 novel alleles found so far with this method, seven have been described previously while three, DRB1*13022, DRB1*1336 and DRB1*1435, are presented here.

New DRB1* alleles (HLA-DRB1*1135, DRB1*1430 and DRB1*1433) and a confirmatory sequence (DRB1*1133).

Three new DRB1 alleles (DRB1*1135, DRB1*1430 and DRB1*1433) and a confirmatory sequence (DRB1*1133) have been identified after following up unusual or novel polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) patterns during routine typing of the DRB1*03,*08,*11,*12,*13 and *14 allele groups. Of the new alleles found and described in this paper, two alleles were initially detected by the PCR-RFLP method which produced unexpected restriction polymorphism (DRB1*1133 and DRB1*1135) while the remaining two were found after following up rare allele typings from this technique (DRB1*1430 and DRB1*1433).

New HLA class II alleles in the Indonesian population.

This paper describes two new class II alleles of the major histocompatibility complex (MHC), DRB1*1431 and DRB3*0303, that have been found in the Indonesian population. In addition, the identification of DRB1*0819 is presented as a confirmatory report.

HLA-DR2 haplotypic diversity in populations of South-East Asia, northern China, Melanesia and Australian aborigines using PCR-RFLP for DRB1, DRB5, DQA1 and DQB1. A novel DRB1 allele: DRB1*16022.

The polymorphism of the human leucocyte antigen HLA-DR2 and the heterogeneity of HLA-DR2 class II-related haplotypes (HLA-DRB1-DRB5-DQA1-DQB1) were investigated in four populations of east and south-east Asia (SEA) and five Melanesian populations using TaqI restriction fragment length polymorphism (RFLP) analysis, and the polymerase chain reaction (PCR) amplification-based techniques PCR-RFLP and sequence-specific oligonucleotide (SSO) typing. The haplotype DRB1*1502-DRB5*0101-DQA1*0102-DQB1*0601 was common in Malaysians, Javanese, Thursday Islanders, Madang, Goroka and the Australian Aborigines, while DRB1*16021-DRB5*0101-DQA1*0102-DQB1*0502 was common in the Thai and Thursday Islanders. DRB1*1501-DRB5*0101-DQA1*0102-DQB1*0602 was present at a high frequency in Northern Chinese, Goroka, Watut and Australian Aborigines. The study describes four rare or unusual haplotypes: HLA-DRB1*1501-DRB5*0101-DQA1*0101-DQB1*0601, DRB1*1502-DRB5*0101-DQA1*0101-DQB1*0502, DRB1*1502-DRB5*0102-DQA1* 0102-DQB1*0502 and DRB1*1501-DRB5*0101-DQA1*0101/2-DQB1*0503; the latter two were confirmed by segregation in two Javanese families. A new DR2 allele, initially detected by PCR-RFLP and confirmed by DNA sequencing as DRB1*16022 (previously designated DRB1*16Madang), was seen in a Madang individual. A new HLA-DR2 TaqI RFLP subtype, locally designated as DR15U, is also described. This RFLP subtype segregated in a Javanese family and correlated with a typically SEA haplotype, DRB1*1502-DRB5*0102-DQA1*0101-DQB1*0501. The allele HLA-DR16Thai, determined by TaqI DRB RFLP, was found by PCR-RFLP and SSO typing to correlate with a unique SEA haplotype, HLA-DRB1*16021-DRB5*0101-DQA1*0102-DQB1*0502, and was observed in the Thai, Malaysian, Thursday Islander, Javanese and Northern Chinese populations.

DNA HLA-DR typing results of 4000 kidney transplants.

Recipients (4076) and donors (3325) of kidney transplants performed at 110 transplant centers were typed for HLA-DRB by the DNA RFLP method. The discrepancy rate of replicate samples distributed among 8 participating laboratories was a low 2.6%. The discrepancy rate between RFLP-DRB and serological HLA-DR typings was 25.0% for organ donors and 27.6% for kidney recipients. Discrepancy rates at the different transplant centers ranged from 9.7% to 86.7%. The discrepancies consisted of antigens being incorrectly interpreted by serology (16.8%), and of serological "blanks" turning out to be definable alleles by the DNA method (10.8%). The alleles that were mainly affected by discrepancies were DR1, DR8, DR10, DR12, DR13, DR14, DR16, DR17.2, and DR18.

Analysis of HLA-DR matching in DNA-typed cadaver kidney transplants.

The effect of matching for HLA-DR antigens was analyzed retrospectively in 3455 cadaver kidney transplants that were typed by the DNA-RFLP method. HLA-DR matching improved the one-year graft survival rate significantly (P < 0.01). Importantly, in 718 first transplants in which the number of mismatches assigned by serological typing was different from that assigned by DNA typing, only the DNA results showed a significant impact of matching on graft outcome (P = 0.03). These results demonstrate that DNA typing is clinically relevant. We were unable to confirm that the HLA-DR6 specificity or the DR6-split DRB1*1302 are associated with poor graft survival.

Analysis of HLA class II allogenotyping in Australian aborigines and Papua New Guinea populations.

Human leukocyte antigen (HLA) class II allogenotyping has been applied to investigate the polymorphism of the DRB, DQB1, DQB2, DQA1, and DQA2 genes in Aborigines from the East Coast of Australia and in Melanesians from the Papua New Guinea North-East Coast and Highlands. Three new DR/DQ arrangements were observed, DRw14/DQB1-2b/DQA1-1a and DRw5Nauru/DQB1-3a/DQA1-2 (n Australian Aborigines), and DRw5Nauru/DQB1-1a/DQA1-1b (in Madang). DQA2 and DQB2 allogenotyping with TaqI and PstI digested genomic DNA revealed little polymorphism among the Papua New Guineans, with DQA2-Xa1 and DQB2-Xb1 the most common alleles in all the groups. However, the presence of DQA2-Xa2 in Papuans and Australian Aborigines reflects the degree of admixture with Caucasoids while the DQA2-Xa4 allele in Madang is probably a marker of Mongoloid origin.

DNA typing: an important step forward? Collaborative Transplant Study.

In a collaborative project which was supported by 96 transplant centers, DNA typing of HLA-DR antigens was carried out on over 7,000 transplant donors and recipients at 8 participating laboratories. Approximately 25% of the individuals were found to have been typed incorrectly by serological means. An analysis of over 2,500 first cadaver kidney transplants showed a significant correlation of matching for the HLA-DR antigens in transplants where the serological typing was confirmed by DNA typing. In transplants where the serological typing was found to be incorrect, the analysis of serological HLA-DR mismatches resulted in no correlation with graft outcome whereas a significant correlation was found when the corrected DNA typed HLA-DR antigens were analyzed. Transplants which had been reported to the Collaborative Transplant Study based on serological typing as matched for HLA-A, -B, -DR or HLA-B, -DR were found to have a superior graft survival rate only if HLA-DR compatibility was confirmed by DNA typing.

Survival of DNA HLA-DR typed and matched cadaver kidney transplants. The Collaborative Transplant Study.

The clinical value of serological HLA matching for cadaver kidney transplantation remains uncertain because the success rate for HLA-matched cadaver transplants is lower than that of HLA-matched sibling grafts. Up to 25% of serological HLA-DR typings may be incorrect when compared with a more accurate DNA-RFLP method, and we have now examined whether incorrect HLA-DR typings account for the lower than expected success rates of HLA-matched cadaver transplants. 58 transplant centres took part in this study and DNA was extracted from over 4000 samples of frozen tissue at the study centre. 8 laboratories then completed blind RFLP typing for HLA-DR. Serological typing data were reported by individual transplant laboratories. 29 of 107 transplants (27%) that were reported as HLA A, B, DR compatible and 76 of 273 (28%) transplants that were reported as HLA B, DR compatible according to serological typing were found to be HLA-DR mismatched by DNA typing. The one-year transplant success rate for DNA-matched HLA, A, B, DR grafts was 87% compared with 69% for mismatched grafts (p less than 0.02); the corresponding success rate for DNA-matched HLA B, DR grafts was 85% compared with 72% for mismatched grafts (p less than 0.01). Many transplants that were previously thought to be HLA matched are mismatched, and this finding may account for previously unexplained graft failures.