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Biomedical subjects

B R Hawkins

Publications and source records attributed to B R Hawkins.

At least 55 records · Page 3Linked to original sources
PubMed1989

Possible evidence for a variant of myasthenia gravis based on HLA and acetylcholine receptor antibody in Chinese patients.

A comprehensive study of 194 Chinese patients with myasthenia gravis in Hong Kong has shown distinct differences from the patterns of disease seen in Caucasians. Restricted ocular myasthenia is the predominant disease type in patients presenting in the first two decades of life and is associated with absence or low titres of acetylcholine receptor antibody. Predisposition to this type of disease is strongly associated with HLA-DRw9. Generalized myasthenia gravis occurs predominantly in patients presenting after the age of 20 years and is accompanied by high titres of acetylcholine receptor antibody but is less strongly associated with HLA-DRw9. It is suggested that myasthenia gravis occurring within the first two decades of life and characterized by affected ocular muscles and absence or low titre of acetylcholine receptor antibody is a genetically determined variant of the disease which occurs commonly in Orientals.

Adult↗
PubMed1988

No apparent association between HLA and multiple sclerosis in southern Chinese.

HLA-A, -B and -DR antigens have been studied in 34 Chinese patients with multiple sclerosis and 100 normal healthy controls. Unlike patients of other ethnic groups in whom multiple sclerosis is associated with HLA-DR2, there was no obvious association with any HLA antigen in the Chinese patients, although the overall distribution of antigens did not appear typical of the southern Chinese population from which the patients were drawn.

Female↗
PubMed1988

HLA typing in the Hong Kong Chest Service/British Medical Research Council study of factors associated with the breakdown to active tuberculosis of inactive pulmonary lesions.

As part of a multifactorial study of the causes of breakdown to active tuberculosis of inactive pulmonary lesions, HLA-A, -B, and -DR typing was performed on 256 Hong Kong Chinese patients and 100 healthy control subjects. Patients were classified into those with smear-positive, active pulmonary tuberculosis (n = 103), those with inactive disease (n = 113), and those with breakdown to active disease after 6 months or more of inactivity (n = 40). Separately, 21 multiple-case families comprising 38 available parents and 93 offspring were examined for HLA haplotype segregation in relation to infection. Results of both studies indicate that among Hong Kong Chinese there is no statistically significant association between HLA and susceptibility to pulmonary tuberculosis.

Adolescent↗
PubMed1987

Strong association between HLA DRw9 and Hashimoto's thyroiditis in southern Chinese.

The distribution of HLA-A, -B, and -DR antigens in 53 Southern Chinese patients with Hashimoto's thyroiditis including 33 with goitre and 20 without goitre was compared with the distribution in 100 Southern Chinese controls. There was a significantly increased prevalence of HLA Bw46 in the nongoiterous patients and of HLA DRw9 in both groups of patients, but only for HLA DRw9 in the goiterous group was the increase significant after adjustment for the number of antigens studied. Based on these findings and those in other autoimmune diseases it is considered that the haplotype Bw46, DRw9 in Chinese takes the place of B8, DR3 in Caucasians in carrying genes which predispose to the development of auto-immune disease.

Adolescent↗
PubMed1987

Strong association of HLA-DR3/DRw9 heterozygosity with early-onset insulin-dependent diabetes mellitus in Chinese.

Studies of Caucasian and Japanese patients with insulin-dependent diabetes mellitus (IDDM) have shown that heterozygosity for certain HLA-DR antigens confers a high risk of developing the disease. The HLA antigens of 75 Chinese patients and 100 Chinese controls in Hong Kong were studied to investigate the role of HLA-DR heterozygosity in Chinese individuals. Some of the patients and controls were also tested for allotypic variation in the complement components C2, C4, and BF. Three alleles, Aw33, B17, and DR3, had increased frequencies in patients compared with controls and frequently occurred together in the same phenotype, which suggested their existence as a haplotype. There were no statistically significant differences in complement allotype frequencies between patients and controls, although the C4B null allele seemed to be associated with Aw33, B17, and DR3. No other HLA-DR antigen appeared to be associated with IDDM. However, when the patients were separated on the basis of age at onset, the frequency of DR3/DRw9 heterozygosity was markedly increased in patients presenting in the first decade of life, but there was no increase in patients presenting at greater than 20 yr of age. DRw9 is strongly associated with autoimmune disease in Chinese, whereas DR3 is not. We suggest that the major IDDM susceptibility locus in Chinese is associated with HLA-DR3 and that patients with HLA-DR3 and HLA-DRw9 have an added predisposition to autoimmune disease and therefore develop IDDM earlier than patients without DRw9.

China↗
PubMed1987

Strong association between the major histocompatibility complex and systemic lupus erythematosus in southern Chinese.

The distribution of HLA-A, B, and DR alleles has been studied in 100 Chinese patients with systemic lupus erythematosus and in 100 healthy Chinese controls. Complement components factor B, C4A and C4B were studied in 72 patients and 61 controls. There was no significant difference between patients and controls in the distribution of HLA-A, HLA-B, factor B and C4B alleles, but there was a significant excess of HLA-DR2 and C4A null in the patients. An unusual variant of C4B was found in 6 patients and 1 control. The possible role of haplotypes is considered in interpreting these results and relating them to previous findings in Chinese.

Adolescent↗
PubMed1986

No association between HLA antigens and adenocarcinoma of the lung in non-smoking Chinese women in Hong Kong.

A high incidence rate of lung cancer with preponderance of adenocarcinoma in non-smokers has been reported in women of southern Chinese ethnic origin. Thirty-three southern Chinese female patients with primary adenocarcinoma of the lung, all lifelong non-smokers, were typed for HLA-A and B antigens to study the possibility of genetically determined susceptibility factors. The antigen frequencies were compared with those of 110 healthy controls. No significant difference in antigen frequencies was found in the patients compared with controls. Studies on other possible factors determining susceptibility to lung cancer in Chinese women are necessary.

Adenocarcinoma↗
PubMed1986

HLA antigens and acetylcholine receptor antibody in the subclassification of myasthenia gravis in Hong Kong Chinese.

Thirty seven Chinese adults and 23 children in Hong Kong with myasthenia gravis were tested for HLA-A and -B antigens and acetylcholine receptor (AChR) antibody. HLA BW46 had a significantly increased prevalence in patients with juvenile onset ocular myasthenia gravis. Only one third of the juvenile ocular patients had AChR antibodies and the titres were generally low. In the adult patients taken as a whole there was a non-significant increase in the prevalence of HLA B5 and HLA B15. HLA BW46 was more prevalent in adult patients without AChR antibody and less prevalent in patients with AChR antibody but the findings were not statistically significant. It is suggested that ocular myasthenia gravis is determined by a pathological mechanism for which susceptibility is determined by HLA BW46. There was a strong correlation between ocular myasthenia gravis and Graves' disease in the adult patients. The possibility that ocular myasthenia gravis is accentuated by a BW46-associated predisposition to ocular Graves' disease is considered.

Adolescent↗
PubMed1985

Infantile myasthenia.

A review of twelve Southern Chinese children whose myasthenic symptoms started within the first two years of life and followed up for one to sixteen years showed that, unlike some previous reports on non-Chinese children, the majority had only ocular myasthenia. Response to pyridostigmine was satisfactory and spontaneous remissions were frequent. Although more boys than girls were affected, familial myasthenia occurred in none. Serum acetylcholine receptor antibodies were not elevated in the majority. An association with HLA A11 and BW 46 needs further confirmation.

Autoantibodies↗
PubMed1985

Association of HLA antigens with thyrotoxic Graves' disease and periodic paralysis in Hong Kong Chinese.

The HLA-A and -B antigen distribution in 132 Hong Kong Chinese patients with Graves' disease, including 24 with thyrotoxic periodic paralysis, was compared with that in 110 controls. The HLA-DR antigen distribution in 68 patients was compared with that in 47 controls. The prevalence of Bw46 was significantly increased in patients with Graves' disease and with periodic paralysis. The prevalence of DRw9 was also slightly increased but not at a statistically significant level. The high prevalence of Bw46 related to patients with early age at onset whereas patients with later age at onset had a significantly increased prevalence of HLA B5. It is suggested that Graves' disease in Chinese is due to two HLA-associated mechanisms in which early-onset disease is associated with Bw46 and late-onset disease with B5.

Adult↗
PubMed1985

Evidence for the existence of HLA A11 subgroups in Hong Kong Chinese.

A study of 771 consecutive blood samples from Hong Kong Chinese has shown the existence of two variants of HLA A11 which can be recognized by antisera of Chinese and other origins. The two variants, identified as HLA A11S (for Short) and HLA A11L (for Long) occurred in 6.4% and 45.9%, respectively, of the samples tested, 2.6% of the samples gave reactions consistent with the presence of both variants and in one case this could be verified by a family study. Segregation of the variants was evident in two other families.

China↗
PubMed1985

Analysis of linkage between HLA haplotype and susceptibility to Graves' disease in multiple-case Chinese families in Hong Kong.

Data from 10 Chinese families in Hong Kong with multiple cases of thyrotoxic Graves' disease were analysed to determine whether genes predisposing to Graves' disease are linked to the HLA region. No evidence was obtained in favour of either dominant or recessive inheritance of HLA-linked susceptibility to Graves' disease. Six of 10 affected parent-offspring combinations had haplotypes containing HLA Bw46 which is more than would be expected from the antigen frequency of Bw46 in normal controls. It is concluded that HLA-associated genes play a role in determining disease susceptibility but that other factors are involved in determining disease expression.

Adult↗
PubMed1984

Strong association of HLA BW46 with juvenile onset myasthenia gravis in Hong Kong Chinese.

The HLA antigen distribution and thyroid autoantibody status of 27 Chinese children in Hong Kong with juvenile onset myasthenia gravis have been compared with 110 healthy university students from the same population. Twenty-four of the patients had ocular myasthenia. There was a significantly increased prevalence of HLA BW46 in the patients compared with controls (67% vs 26.4%, p less than 0.005) indicating that BW46 confers a relative risk of 5.6 for juvenile onset myasthenia gravis in Chinese children. The increased prevalence of BW46 was not associated with thyroid autoimmunity in the patients although the antigen is known to be associated with thyrotoxicosis in Chinese. The possibility that BW46 confers protection against the development of acetyl-choline receptor antibodies in Chinese patients is discussed. One patient had the Caucasian antigen B8 and the question whether defective immune response genes were introduced into the Chinese through Caucasian admixture is raised.

Autoantibodies↗
PubMed1983

A population genetic study of the Banks and Torres Islands (Vanuatu) and of the Santa Cruz Islands and Polynesian Outliers (Solomon Islands).

As part of a multidisciplinary survey of populations in the Banks and Torres Islands of Vanuatu and the Southern and Central Districts of the Solomon Islands, nearly 2,400 persons have been tested for ABO blood groups and a number of serum protein and red cell enzyme genetic marker systems. For the ABO system, the populations are characterized in general by high gene O and low gene B frequencies except in two of the Polynesian Outlier Islands, Rennell and Bellona, which have high frequencies of B. Among the serum proteins, several alleles have distributions indicating significant movement of people between islands. These include Albumin New Guinea and the transferrin alleles TfD1, and TfBLae, and TfB2. Similar specific alleles for red cell enzymes also show distributions reflecting interisland population movement as well as contact with persons from outside the southern Pacific region. Examples are ACPR1 in the acid phosphatase system, PGM31 and PGM71, PGM92, and PGM102, PGK4 and also HbJTongariki. The data available for 11 polymorphic systems were used to generate genetic distances. Of the four Polynesian Outlier Islands, Anuta is most remote genetically, with Rennell and Bellona also relatively isolated. The fourth Polynesian Outlier, Tikopia, occupies a position genetically close to the Melanesian populations of the Banks and Torres Islands and the southern Solomons. The history of early European contact and voyaging in the Pacific, as well as archaeological and linguistic evidence and local legends, indicate that significant movements of people occurred between islands and provided opportunities for genes to be introduced from Europeans, Africans, and Asians. The genetic marker studies give evidence for genes from all these sources, though at a low level. Despite this admixture, the Polynesian Outlier and Melanesian populations have preserved their own distinctive genetic patterns.

ABO Blood-Group System↗