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K Pile

Publications and source records attributed to K Pile.

25 records · Page 2Linked to original sources

Systematic study of human alpha beta T cell receptor V segments shows allelic variations resulting in a large number of distinct T cell receptor haplotypes.

The variation of the alpha beta T cell receptor (TCR) results mainly from rearrangements of germ-line V, D and J elements combined with the processes of N- and P-region addition. In addition to this extensive diversity, diallelic polymorphism is also recognized in V regions of beta loci. Four such polymorphisms have previously been defined, but the full extent of such variation has not yet been established. To investigate allelic polymorphism, we used a strategy based V locus-specific polymerase chain reaction and single-strand conformation polymorphisms. Studying the two V beta 2 loci and the V alpha 8.1 locus, we found that all exhibited a coding polymorphism. One of the V beta 2 loci proved to be the first multiallele segment to be recognized, with three common variants. The second V beta 2 locus, for which none of the two alleles has been identified in cDNA, appeared in fact to be a V beta orphon, in abnormal location on the chromosome 9. A yeast artificial chromosome containing part of the TCRB locus allowed us to place the first V beta 2 segment on the known map to define haplotypes with two other polymorphic segments: V beta 1 and V beta 6.7. Multiple distinct haplotypes result from combinations between these polymorphic loci, showing that V beta regions are highly variable between individuals. Two alleles exist at the V alpha 8.1 segment and both are expressed. This represents the first example of a frequent coding polymorphism for TCRA gene. The distribution of allele frequencies for these segments suggest the action of balancing selection. These data add a further dimension to TCR polymorphism and suggest new candidates to explore TCR-encoded susceptibility to autoimmune diseases.

Alleles↗

Analysis of a T-cell receptor V beta segment implicated in susceptibility to rheumatoid arthritis: V beta 2 germline polymorphism does not encode susceptibility.

OBJECTIVES: The assessment of allelic polymorphism of the T cell receptor gene segment, TCRBV2S1, in rheumatoid arthritis. METHODS: A total of 136 patients with rheumatoid arthritis (RA) (ACR criteria) and 150 controls were TCRBV2S1 genotyped using a nested PCR amplification strategy followed by single-strand conformation polymorphism (SSCP) analysis. RESULTS: The SSCP typing method detected two previously unknown alleles of the TCRBV2S1 gene segment. The TCRBV2S1 allele, genotype and inferred phenotype frequencies were similar in the RA patients and controls. No differences were apparent after the RA patients had been partitioned according to their HLA-DR genotypes. CONCLUSIONS: SSCP analysis is a rapid and efficient method of typing T cell receptor germline polymorphisms. Allelic polymorphism of the T cell receptor variable segment, TCRBV2S1, does not influence susceptibility to RA.

Alleles↗

Polyarteritis associated with Yersinia enterocolitica infection.

A patient developed polyarteritis, predominantly affecting the muscles, 10 days after a Yersinia enterocolitica O:3 infection. Immunoperoxidase staining showed Yersinia enterocolitica O:3 antigen in the subendothelial layer of the blood vessels. This suggests that vasculitis should be considered as a rare manifestation of Yersinia enterocolitica infection.

Adult↗

Scleroderma renal crisis: poor outcome despite aggressive antihypertensive treatment.

BACKGROUND: Scleroderma renal crisis (SRC) is a rare but feared complication of scleroderma. Angiotensin--converting enzyme (ACE) inhibition has significantly improved survival, but it is unknown whether prophylactic ACE inhibitors will prevent this complication. AIMS: To determine: (i) the frequency of SRC in our cohort of well-characterized scleroderma patients resident in South Australia, (ii) any predisposing clinical and serological features, (iii) median disease duration at which SRC occurs, (iv) possible precipitants, (v) disease outcome, and (vi) whether patients were taking ACE inhibitors prior to onset of SRC. METHODS: Systematic review of the clinical course of all patients registered on the South Australian Scleroderma Register. RESULTS: SRC occurred in 16 patients. This constituted 2.8% of a total scleroderma cohort and 15% of the diffuse scleroderma cohort identified in South Australia. All 16 patients had diffuse cutaneous scleroderma. SRC occurred at a median disease duration of 15 months (range 1 week-11 years). Disease outcome was poor (five deaths, three requiring long-term dialysis and only two patients regaining a normal creatinine) despite aggressive antihypertensive treatment (including ACE inhibitors) in an intensive care or specialized renal unit. Two patients were later able to discontinue dialysis. Only two patients were taking small doses of ACE inhibitors prior to the onset of their SRC. The frequency of Scl-70 was decreased in the SRC group (P = 0.003). CONCLUSION: SRC is a rare event occurring in a small proportion of patients with diffuse scleroderma. The outcome of SRC was poor despite aggressive antihypertensive treatment. It is hypothesized that prophylactic ACE inhibition in susceptible patients might prevent or ameliorate this complication.

Adult↗