Publications by authors named "W Leheny"

10 Publications

Histocompatibility antigens in Omanis: Comparison with other Gulf populations and implications for disease association.

Ann Saudi Med 1999 May-Jun;19(3):193-6

Transplant Immunology Laboratory, Department of Surgery, College of Medicine, Sultan Qaboos University, Muscat, Sultanate of Oman.

Background: This is the first comprehensive report of HLA antigens in Omanis, and the first application of HLA sequence-specific primer (SSP) DNA typing in a Gulf population. The objective was to compare the findings with other Gulf populations and assess their implications for disease association.

Patients And Methods: HLA typing was carried out on 321 healthy Omanis. One hundred and twenty-six of these were typed for Class II antigens by low-resolution SSP DNA typing. The results were compared with other HLA antigen frequencies recorded from Kuwait and Saudi Arabia.

Results: The Omani population was characterized by a very high incidence of HLA-DR2 (66%), with associated HLA-DQ1 (76%) and a reduced incidence of DR4, DR7 and DR53. The incidence of DR2 is the highest recorded worldwide. HLA-A11, A32, B17, B35 and B40 were significantly higher than in Kuwait and Saudi Arabia, and A9, B21(B50) significantly lower (Pc<0.05). HLA-B27 is very low in the Omani population (0.3%). The high incidence of HLA-DR2 in Oman and disparities in the frequency of other antigens would indicate that there has not been any significant migration from northern Arabia. Class II DNA typing revealed that DR16 was the predominant split of DR2 (63%), with DR15 being 18% and both DR15 and 16 being found in 6%, giving a total of 87% for A centAADR2A centAA-associated antigens (serology of the same individuals gave a DR2 incidence of 74%). The major disparity between serology and DNA typing was in the definition of DR4 (serology 8%, DNA 14%) and DR51 (53% vs. 70%).

Conclusion: The frequency of many HLA antigens in Omanis differs significantly from frequencies found in the populations of Kuwait and Saudi Arabia, possibly reflecting different migration patterns. The high incidence of HLA-DR2 in Oman may have important implications for disease association.
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http://dx.doi.org/10.5144/0256-4947.1999.193DOI Listing
October 2012

Frequency of cytokine polymorphisms in populations from western Europe, Africa, Asia, the Middle East and South America.

Hum Immunol 2002 Nov;63(11):1055-61

Northern Ireland Regional Histocompatibility and Immunogenetics Laboratory, City Hospital, Belfast, Northern Ireland.

PCR-SSOP identification procedures for IL-2, IL-6, IL-10, TNF-alpha and TNF-beta cytokine polymorphisms have been developed. Application of the procedures to a range of diverse geographically distributed populations has identified ethnic differences within the groups studied. Five populations were investigated, Northern Ireland, South African Zulu, Omani, Singapore Chinese and Mexican Mestizos.
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http://dx.doi.org/10.1016/s0198-8859(02)00440-8DOI Listing
November 2002

Characterization of HLA-B*3921 and confirmation of HLA-B*4415, two variant HLA-B alleles identified in the Omani population.

Tissue Antigens 2000 Oct;56(4):376-9

Northern Ireland Regional Histocompatibility and Immunogenetics Laboratory, City Hospital, Belfast.

We describe a variant HLA-B*39 allele present in two individuals from Oman, which has been officially named HLA-B*3921. In addition we confirm the existence of HLA-B*4415, an allele closely related to HLA-B*4501 differing only at the Bw4/Bw6 epitope.
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http://dx.doi.org/10.1034/j.1399-0039.2000.560411.xDOI Listing
October 2000

HLA antigens in Omanis with blinding trachoma: markers for disease susceptibility and resistance.

Br J Ophthalmol 1997 Jun;81(6):431-4

Department of Surgery, College of Medicine, Sultan Qaboos University, Muscat, Sultanate of Oman.

Aim: To determine the presence of HLA antigens in people with blinding trachoma.

Methods: Fifty Omanis with blinding trachoma were serologically typed for HLA A, B, C, DR, and DQ antigens and DNA typed for class II DR beta and DQ beta alleles and compared with a population of 100 healthy controls.

Results: chi 2 analysis of serological reactions did not reveal any significant differences in HLA antigen frequencies after correction of probability, although DR4, DR7, and DR53 were completely absent in the patients and all of the patients were HLA DQ1 positive. In the case of DQ1 the relative risk was 22.6 (95% confidence interval of 20.7-24.7). Class II DNA low resolution DR beta typing showed a significant increase in HLA DR16 (pc = 0.036, relative risk = 3.8) and a significant decrease in HLA DR53 (pc = 0.018, relative risk = 0.05).

Conclusion: The finding that HLA DR16 (a DR2 subtype) is associated with susceptibility to blinding trachoma, a disease that is caused by an intracellular micro-organism, is consistent with reports of an HLA DR2 association with leprosy and tuberculosis, diseases also caused by an intracellular micro-organism. Similarly, resistance to leprosy is associated with HLA DR53 as is the case with blinding trachoma described here. It is postulated that HLA DR2 or subtypes in association with HLA DQ 1 may enable an intracellular micro-organism to enter the cell or are involved in presentation of peptides derived from intracellular micro-organisms to T lymphocytes initiating a delayed hypersensitivity or autoimmune reaction. These findings are the first report that genetic factors are of major importance in the development and protection against blinding trachoma.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1722211PMC
http://dx.doi.org/10.1136/bjo.81.6.431DOI Listing
June 1997

HLA antigens in an Omani population with dilated cardiomyopathy.

Int J Cardiol 1996 Jul;55(1):29-32

Department of Medicine, College of Medicine, Sultan Qaboos University, Sultanate of Oman.

We have investigated the frequency of HLA antigens in 50 Omanis with idiopathic dilated cardiomyopathy to establish whether there are ethnic/racial differences in the reported HLA associations with this disease. There were no statistically significant HLA-A, B, C, DR or DQ antigen frequency differences between the patients and 247 healthy Omanis. THe reported association of HLA-DR4 with idiopathic dilated cardiomyopathy in the Caucasian population does not apply to the Omanis. This confirms the heterogeneity of this disease and points to ethnic/racial origins as important factors when examining the HLA association. This is particularly pertinent as HLD-DR4 has been strongly linked to autoantibody formation in idiopathic dilated cardiomyopathy in Caucasians. The lack of any HLA antigen association in Omanis would argue against the proposed HLA-linked autoimmune pathology of idiopathic dilated cardiomyopathy.
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http://dx.doi.org/10.1016/0167-5273(96)02625-3DOI Listing
July 1996