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P Chiewsilp

Publications and source records attributed to P Chiewsilp.

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

HLA-B27 subtypes in Asian patients with ankylosing spondylitis. Evidence for new associations.

The aim of this study was to investigate the contribution of the different B27 subtypes to ankylosing spondylitis (AS) susceptibility. The polymerase chain reaction (PCR) in combination with the sequence-specific oligonucleotide probes (SSOs) was used to analyse the polymorphism in exon 2 and 3 of HLA-B27 in two Asian groups with different genetic HLA structures: Indian (I) and Thai (T) populations. The same number of AS patients (45) and healthy B27 positive donors (n = 17) from both populations were analysed in order to ascertain the B27 subtypes. Three different findings can be concluded from this study: 1) B*2707 has been found to be associated with AS in both populations. This association has not been previously reported in either ethnic group. 2) B*2704 is strongly associated with AS in the Thai patients (91% in AS vs. 47% in C; RR = 11.5; EF = 0.83). In contrast, B*2704 was found with similar frequency in Asian Indians AS patients and controls (41% in AS vs. 41% in C.). 3) B*2706 was found overrepresented in control populations and absent in AS patients (0% in AS vs. 47% in C.; pc < 10(-6)) showing the maximum value of protective fraction (PF = 1). The B*2706 negative association with AS has not been previously described in other ethnic groups and could indicate a protective effect of this subtype on AS susceptibility. The B*2706 allele has two changes relative to B*2704 at residue 114 (His to Asp) and 116 (Asp to Tyr) in the pockets D/E. The importance that these differences can play in the pathogenesis of AS are discussed.

Amino Acid Sequence↗
PubMed1994

HLA class II polymorphism in Thai insulin-dependent diabetes mellitus.

Fifty-seven Thai IDDM patients were studied for HLA class I by LCT and HLA class II by LCT and PCR-RFLP. It was found that DRB1*0301, DR3, DQB1*0201, DRB3*0202, DQA1*0501 and DQ2 were significantly increased with R.R. = 10.0, 6.6, 4.2, 3.7, 3.5 and 3.2 and Pc < 0.005, 0.001, 0.01, 0.005, 0.01 and 0.005, respectively. In contrast, DQA1*0101, DRB3*0301, DR5 and DQ1 were significantly decreased with R.R. = 0.2, 0.2, 0.3 and 0.5 and Pc < 0.01, 0.05, 0.01 and 0.05, respectively. The primary factor for IDDM susceptibility is probably DRB1. The homozygous Asp57/Asp57 DQB1 genotype appears to determine resistance to IDDM while Arg52-DQA1, non-Asp57-DQB1 haplotype confers susceptibility to IDDM. The common haplotypes in Thai IDDM cases were DRB1*0301, DRB3*0202, DQA1*0501, DQB1*0201, DPB1*0401 and DRB1*0405, DQA1*0301, DQB1*0402 (or 0401 or 0302), DPB1*0401 (or 0301 or 1501). The less common haplotypes were DRB1*0406, DQA1*0301, DPB1*0302, DPB1*0501 and DRB1*1202, DRB1*0301, DQA1*0601, DQB1*0301, DPB1*0501. DR3 was increased in both gender groups with early onset (< 10 years) regardless of a family history of DM. However, DR3/DR4 genotype was increased only in female patients with a family history of DM and early onset. In conclusion, DRB1, DRB3, DQA1 and DQB1, but not DPB1 are involved in the occurrence of IDDM. The cooperation of HLA class II and X-chromosome may contribute to the development of IDDM in addition to other factors such as other genetic (chromosomes 11, 19, 14, 7), immunologic and environmental factors which require further study.

Adolescent↗
PubMed1993

HIV transmission by seronegative blood components: report of 2 probable cases.

HIV seroconversion was reported in 2 haemophiliacs after having corrective orthopaedic surgery. They received solvent-detergent/heat-treated factor VIII concentrate, HIV-seronegative cryoprecipitate and fresh frozen plasma during the course of surgery. HIV seroconversion was found on days 31 and 71 after surgery. It is highly probable that the infections were acquired by transfusions of seronegative blood components. In countries with a relatively low prevalence of HIV infection, transmission of HIV by transfusion of derivatives of seronegative blood is occasionally reported as a rare complication of blood transfusion [1-3]. In Thailand the prevalence of HIV infection and the incidence of new infections in the general population and in blood donors has recently increased dramatically (fig. 1) [4-5]. As a result of these components prepared from HIV-seronegative blood donations pose a significant hazard to recipients because of the risk of viraemia during the 'window period' of HIV infection. Here we report HIV infection in 2 haemophilia patients treated with HIV-seronegative (using Fujirebio agglutination or second-generation Abbott ELISA) cryoprecipitate and fresh frozen plasma in 1991, prepared locally from single-unit donations. All donors were voluntary. Anti-HIV was tested in every unit of donor blood before processing to blood components. Although not proven, it is highly probable that the infections were acquired by transfusions of seronegative blood components.

Adolescent↗
PubMed1993

HTLV-I antibody screening in donated blood and thalassemic patients.

The HTLV-I antibody screening by passive partial agglutination test, Serodia HTLV-I (Fuji-rebio Inc) was performed in a total of 1,225 male and 468 female blood donors from September 1992 to March 1993. In addition, a total of 64 multitransfused thalassemic patients were also studied. All of the sera from donors and patients in both study groups showed no reactive results for HTLV-I antibody. This finding indicated that the HTLV-I infection is not yet a problem in blood transfusion in Thailand. However, the scattered reports of HTLV-I infections from our region should urge the national authority on the surveillance of this infection by epidemiological survey and occasional screening in blood donors.

Antibodies, Viral↗
PubMed1993

Transmission of HIV infection by seronegative blood in Thailand.

In Thailand, the prevalence of HIV infection in the general population and in donor blood (DB) has sharply increased since 1987. The HIV seropositive rate in DB was increased from 0.0065 per cent in 1987 to 0.95 per cent in 1993 (150 times in 6 years). Heterosexual transmission is the major route of spreading. Therefore, HIV seronegative blood (SNB) poses significant hazard to the recipients because of the risk of viraemia during the window period of early HIV infection. In Thailand HIV Ab screening in all units of blood was started in 1987 and was compulsory nationwide in early 1989. Donor self exclusion (DSE) has been implemented since 1990. It is not fully effective in the prevention of transfusion associated AIDS (TAA) because of many limiting factors. However, DSE should be promoted to practice in every blood bank particularly those that can not do HIV Ag screening. During 1990-1992, there were 30 reported cases of TAA by SNB. The study of risk figure (HIV Ag positive-neutralization with HIV Ab negative) in DB was 1:3,400 and 1:10,000 in two reports in 1991. Under all these circumstances, the national AIDS committee has documented the policy to do HIV Ag screening in every unit of blood from August 1991 and allocated a 10 million baht budget (year 1992) for Ag testing. Several hospitals and NBC reported the risk figures which varied from 1:3,400 to 1:25,000. A certain amount of blood is processed to 2-4 blood components given to 2-4 patients which will increase the number of TAA by SNB.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Donors↗