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B Tait

Publications and source records attributed to B Tait.

At least 37 records · Page 2Linked to original sources
PubMed1995

Similar peptides from two beta cell autoantigens, proinsulin and glutamic acid decarboxylase, stimulate T cells of individuals at risk for insulin-dependent diabetes.

BACKGROUND: Insulin (1) and glutamic acid decarboxylase (GAD) (2) are both autoantigens in insulin-dependent diabetes mellitus (IDDM), but no molecular mechanism has been proposed for their association. We have identified a 13 amino acid peptide of proinsulin (amino acids 24-36) that bears marked similarity to a peptide of GAD65 (amino acids 506-518) (G. Rudy, unpublished). In order to test the hypothesis that this region of similarity is implicated in the pathogenesis of IDDM, we assayed T cell reactivity to these two peptides in subjects at risk for IDDM. MATERIALS AND METHODS: Subjects at risk for IDDM were islet cell antibody (ICA)-positive, first degree relatives of people with insulin-dependent diabetes. Peripheral blood mononuclear cells from 10 pairs of at-risk and HLA-DR matched control subjects were tested in an in vitro proliferation assay. RESULTS: Reactivity to both proinsulin and GAD peptides was significantly greater among at-risk subjects than controls (proinsulin; p < 0.008; GAD; p < 0.018). In contrast to reactivity to the GAD peptide, reactivity to the proinsulin peptide was almost entirely confined to the at-risk subjects. CONCLUSIONS: This is the first demonstration of T cell reactivity to a proinsulin-specific peptide. In addition, it is the first example of reactivity to a minimal peptide region shared between two human autoimmune disease-associated self antigens. Mimicry between these similar peptides may provide a molecular basis for the conjoint autoantigenicity of proinsulin and GAD in IDDM.

Adolescent↗
PubMed1994

Lpr and MRL background gene involvement in the control of adjuvant enhanced arthritis in MRL-lpr mice.

The MRL-lpr mouse strain develops a mild spontaneous arthritis which can be enhanced by the intradermal injection of complete Freund's adjuvant (CFA). In this study we examined the requirement of the lpr gene and background MRL genes on CFA-enhanced murine arthritis. MRL+, MRL-lpr, AKR/J, and B6-lpr mice (experimental) and B6 mice (control) were injected intradermally with CFA containing M. tuberculosis H37 RA. The development of swelling and erythema was monitored for 1 month after the injection, when the histopathology of the joints was investigated. It was found that while 74% of both 7-month-old MRL + and 3-month-old MRL-lpr mice and 11% of AKR/J mice displayed clinically visible arthritis, B6, B6-lpr, and 3-month-old MRL+ did not develop the condition after CFA treatment. In accordance with the clinical observations, the histopathological changes were manifested only in older MRL+, AKR/J and 3-month-old MRL-lpr mice. One month after the CFA injection, milder changes were observed in the MRL+ than in the MRL-lpr mice, with the MRL+ mice developing a disease of similar severity to uninjected MRL-lpr mice. The AKR/J mice demonstrated the least severe histopathological changes. In the long term (150 days) more severe destructive changes could be demonstrated in the cartilage and bone of the MRL+ mice although the average histological scores did not show statistically significant differences from those found in the MRL+ 30 days after injection. The serological evaluation of the adjuvant-injected mice demonstrated significantly enhanced antibody production to type II collagen and M. tuberculosis, but did not correlate with the disease activity. These observations suggest that while the lpr gene causes a more severe early effect, background genes other than the lpr are more involved in the adjuvant-enhanced arthritis-afflicted mice.

Age Factors↗
PubMed1994

Multiple non-melanoma skin cancer: evidence that different MHC genes are associated with different cancers.

HLA DR frequencies of patients with multiple non-melanoma skin cancers were analysed. There were significant differences in the frequencies of HLA DR1, DR4 and DR7 between patients who only had basal cell carcinomas and patients who had both basal and squamous cell carcinomas. There were significant differences in the frequency of HLA DR53 between the two groups. This antigen is in linkage disequilibrium with HLA DR4 and DR7, and it is not possible to distinguish the primary susceptibility locus.

Adult↗
PubMed1993

HLA DR4 is associated with the development of multiple basal cell carcinomas and malignant melanoma.

An association between HLA DR4 and the development of multiple basal cell carcinomas (BCC) and malignant melanoma (MM) was detected in southern Australia. There were highly significant differences in HLA DR frequencies between patients with multiple BCCs and MM and matched patients with multiple BCCs only. These findings suggest that hereditary factors associated with the HLA system influence what types of multiple skin cancers people develop.

Adult↗
PubMed1992

HLA-DR1 is not a sign of poor prognosis for the development of multiple basal cell carcinomas.

BACKGROUND: HLA-DR1 is associated with the development of multiple basal cell carcinomas (BCC). However, the association is weak. OBJECTIVE: The purpose of our study was to determine whether HLA-DR1 is a marker for susceptibility to the development of many BCCs during a lifetime. METHODS: Persons with multiple BCCs were placed into two groups: those with less than 10 and those with 20 or more. In addition, the HLA-DR1 frequencies were analyzed. RESULTS: HLA-DR1 was associated with multiple BCCs in the group with less than 10 BCCs but not with the other group. These patients were significantly younger on average than those with 20 or more BCCs. CONCLUSION: HLA-DR1 is associated with the development of multiple BCCs at an early age but it is not associated with development of large numbers of BCCs. The amount of UV light a person receives appears to be more important.

Age Factors↗
PubMed1992

Multiple basal cell carcinoma in tropical Australia.

No association between HLA DR1 and the development of multiple basal cell carcinomas (BCC) was found among patients who had lived at least two-thirds of their lives in the tropics. The percentage of patients with multiple BCCs increased with age; this was different from what has been found in people living in the temperate zone of Australia.

Adult↗
PubMed1992

Skin cancers and HLA frequencies in renal transplant recipients.

An association between HLA DR7 and the development of multiple non-melanoma skin cancer was detected in immunosuppressed patients in southern Australia. The relative risk was 2.6 which was lower than for immunocompetent patients with the same skin cancers. HLA frequencies of renal transplant recipients with multiple skin cancers were determined. The types HLA B27 and HLA Dr7 were found in significantly higher frequency, and there was no absence of HLA A11.

Adult↗
PubMed1991

Multiple basal cell carcinomas and HLA frequencies in southern Australia.

An association between HLA-DR1 and the development of multiple basal cell carcinomas was detected in southern Australia. A reduction in HLA-DR4 was found in patients with basal cell carcinoma compared with a local control group. The relative risk for HLA-DR1 was 2.1, which was lower than that for persons in farther countries from the equator.

Adult↗
PubMed1991

Age and multiple basal cell carcinomas in Australia.

A survey of patients with skin cancer in southern Australia detected that the development of multiple BCCs is common. The incidence of multiple BCCs peaks during the sixth decade and reaches a plateau. Human leukocyte antigen (HLA) DR1 was associated with the development of multiple BCCs in people under the age of 55, but not in older people.

Adult↗
PubMed1991

Relationship of progression of radiographic changes in hands and wrists, clinical features and HLA-DR antigens in rheumatoid arthritis.

One hundred and twelve hospital based outpatients with rheumatoid arthritis (mean duration +/- standard error, 10.7 +/- 0.9 years) were studied for radiological progression of the hands and wrists over a mean period of 26.5 +/- 0.5 months. The majority were taking slow acting antirheumatic drugs (SAARD). The rate of radiographic progression was positively and independently associated with the female sex (p less than 0.01), erythrocyte sedimentation rate (ESR, p less than 0.05) and HLA-DR1 (p less than 0.05). There was a negative association with HLA-DR4 (p less than 0.05) but this was no longer significant after adjusting for ESR. There was no relationship between the rate of radiological progression and the presence of rheumatoid factor, rheumatoid nodules and duration of treatment with SAARD.

Arthritis, Rheumatoid↗
PubMed1990

Associations between HLA and antibodies to collagen in rheumatoid arthritis.

Associations between HLA types and serum antibodies to native and denatured type II collagen were sought in 105 patients with rheumatoid arthritis (RA). Antibodies were measured using a solid phase radioimmunoassay. There were no significant associations between any HLA antigen (A, B, or DR) and a high antibody titre to native collagen. There were significant associations, however, between HLA antigens and high antibody titres to denatured collagen. Although DR4 did not show an association, the phenotype A2+DR4+ did; this was not related to A2 as A2+DR- was not associated with a high antibody titre. No single B locus antigen showed an association, but several B locus antigens, B12, B15, and B40, were included in phenotypes with A2 and DR4 which were associated with a high antibody titre to denatured collagen. These HLA associations with anticollagen type II are best explained by a gene other than DR4 (but in linkage with it) which may regulate the antibody response to denatured collagen. If so, this would represent an HLA gene in addition to DR4 that is active in RA.

Antibodies↗
PubMed1990

HLA-DQ beta sequence polymorphism and genetic susceptibility to IDDM.

The analysis of HLA-DQ beta nucleotide sequence polymorphism in insulin-dependent diabetes mellitus (IDDM) patients and control subjects suggests a role for the DQ beta-chain in genetic susceptibility. Sequence determination and oligonucleotide hybridization was carried out on enzymatically amplified DNA from various HLA-DR-typed individuals, including the rare class of DR2+ patients. In the analysis of DQ beta variation in DR4, DRw6, and DR2 haplotypes, a correlation was observed between the presence of the negatively charged residue Asp at position 57 and low susceptibility and the presence of an Ala (DR4), Val (DRw6), or Ser (DR2) and higher susceptibility. However, important exceptions to this pattern have been identified in the analysis of heterozygous DR1/4 IDDM patients. In these individuals, susceptibility appears to correlate with specific DR beta l alleles (Dw4) on the DR4 haplotype, rather than with the DQ beta allele (DQB3.2) that contains Ala at position 57. The DQ beta alleles found in some Chinese IDDM patients also proved discordant with the position-57 correlations. Thus, although there is a general correlation between the residue at position 57 of the DQ beta-chain and IDDM susceptibility, these data do not support the notion that Asp 57 confers complete resistance or protection to IDDM. In general, these results suggest that IDDM susceptibility is conferred by specific combinations of DQ beta and DR beta sequences.

Alleles↗
PubMed1989

HLA A1, B8, DR3 extended haplotypes in autoimmune chronic hepatitis.

Genetic determinants of the autoimmune type of chronic active hepatitis include the major histocompatibility complex alleles HLA-B8 and HLA-DR3, which are usually present as the haplotype A1, B8, DR3. In certain other autoimmune diseases, an extended haplotype including complement alleles confers a greater relative risk than does B8, DR3. Hence, extended haplotypes were ascertained in autoimmune chronic active hepatitis by typing for HLA, complement alleles C4A, C4B, and Bf, and glyoxalase type 1 or 2. Eight of the 10 B8, DR3 haplotypes were A1, B8, DR3. Of the 8, 7 had the extended haplotype A1, B8, C4AQ0, C4B1, BfS, DR3, but this haplotype occurred in four instances with glyoxalase 2 and in three with glyoxalase 1. Thus, we find that in autoimmune chronic active hepatitis there is a high frequency of null alleles for complement but an extended haplotype does not cause any greater risk for disease than B8, DR3 alone.

Alleles↗
PubMed1988

Histocompatibility antigens and habitual abortion.

Eighty-five couples with habitual abortion were studied: 43 were primary aborters (i.e., had no advanced pregnancy beyond 20 weeks gestation), and 42 were secondary aborters. The only significant finding in primary female aborters was a reduction in the incidence of B35. In contrast, in secondary female aborters there was a reduction in the incidence of DR3 and A1/B8/DR3 and an increase in the degree of homozygosity of HLA B. In the male partners of primary aborters, there was a reduced incidence of DR3 and A1/B8/DR3. In addition, in male partners of both primary and secondary aborters, there was increased HLA-B homozygosity and increased frequency of DR4-5 phenotype. Increased sharing of HLA antigens between partners was not found to be significantly different from the control population. These findings emphasize that primary and secondary female aborters form distinct populations, which could explain differences in immunological responses to various antigens, including fetal-related antigens. The closely related findings in female secondary aborters and male partners of primary aborters are intriguing but cannot be explained. Whether or not these genetic markers bear any relationship to reproductive success remains to be determined.

Abortion, Habitual↗
PubMed1987

Collagen antibodies in Ross River virus disease (epidemic polyarthritis).

Antibody activity against collagen was measured in 53 samples of serum from 48 patients with active signs of epidemic polyarthritis (EPA) following infection with Ross River virus. Activity was higher against denatured collagen than against native collagen, but was within the normal range for each. Determination of HLA phenotypes permitted a search for any relationship between HLA type and differences in collagen antibody levels within the normal range. No relationship was detected with HLA antigens predominating in EPA or with HLA antigens that are associated with high collagen-antibody levels in rheumatoid arthritis (RA), which suggests that the latter associations may represent failure to control collagen antibody levels after the onset of RA. The findings also provide evidence against a role for nonspecific enhancement of humoral immune responses in the pathogenesis of EPA, and constitute a further point of distinction between EPA and RA.

Adolescent↗