Preliminary study of HLA-ABCDR antigens in CML, ANLL, thalassemia and severe aplastic anemia in Thais.

The objective of this study was to analyse human leukocyte antigen (HLA) and disease association in common blood diseases [chronic myelogenous leukemia (CML), acute nonlymphocytic leukemia (ANLL), thalassemia and severe aplastic anemia] in Thais. The subjects were patients from the Hematological Clinic, Departments of Medicine and Pediatrics, Ramathibodi Hospital who were referred for HLA typing for bone marrow transplantation (BMT) at the Histocompatibility Laboratory from March 1988 to September 1997. A total of 129 patients had complete HLA-ABC typing. The patients included 45 CML, 40 ANLL, 26 thalassemia (Thal) and 18 severe aplastic anemia (SAA). Of these, 88 patients were typed for HLA class II. The HLA class I (ABC) and II (DR, DQ) typings were performed by microlymphocytotoxicity test. It was found that HLA class I was associated with CML, ANLL and Thal, whereas, HLA class II was associated with SAA. HLA-B8 and HLA-B18 were increased in CML with R.R. values of 12.2 and 3.9, respectively, whereas, HLA-B18 was increased in ANLL with R.R. value of 4.5. In addition, HLA-DR2 and DR3 were increased in SAA with R.R. values of 3.8 and 4.8, respectively. For Thal, HLA-A2 and B46 were increased in Thal in Central Thais with R.R. values of 3.3 and 6.1, respectively, whereas, HLA-B13 was increased in Thal in Northern Thais with R.R. value of 8.5. On the other hand, HLA-B7 was absent in CML. HLA-Cw7 was decreased in CML and SAA, whereas, HLA-DR6 was decreased in ANLL and SAA. Furthermore, HLA-Cw6 was also decreased in CML, whereas, HLA-A33 and Bw4 were decreased in SAA. Although the sample size of each disease was small, the increase of HLA-DR2 was observed in SAA in Thais which was similar to other studies in different ethnic groups. These preliminary data may be useful for further study in HLA and blood disease association.

Panel reactive antibodies in post-kidney transplantation.

This study was aimed to evaluate the clinical relevance of the panel reactive antibodies (PRA) post kidney transplantation (KT). A total number of 90 KT recipients consisted of 71 male and 19 female patients. Thirty-two haploidentical and 3 HLA-identical pairs for living related KT and 55 cadaveric KT with 3-6 mismatched antigens were included in this study. The analysis revealed that there were 2 out of 69 (2.89%) patients with no episode of rejection who had Pre-KT PRA-T and or PRA-B > 80 per cent while they were 5.79 per cent and 23.19 per cent for Post-KT. No patient in 21 cases with KT rejection had Pre-KT-PRA-T and -B > 80 per cent. There was significant increase of antibodies in Post-KT rejections which were 28.57 per cent and 33.3 per cent for Post-KT-PRA-T and -B respectively. None of 3 cases with graft failure (GF) from chronic rejection had Pre-KT-PRA-T and -B > 20 per cent and only one of them had Post-KT-PRA-T = 80 per cent. No donor specific HLA antibody was found among this group of patients. Although antibody to donor HLA antigens was not observed in these patients, the increase of PRA-T and -B in Post-KT may indicate the immunological reaction resulting in GF.

HLA in southern Thai-Muslims.

One hundred and two Southern Thai-Muslims (STM) from Nakhon Si Thammarat province were studied for HLA class I and II by SSP ARMS-PCR and PCR-SSO, respectively. The allele frequencies, haplotype frequencies, delta value and linkage disequilibrium between alleles were expressed. The most frequent alleles for HLA-A, HLA-B and HLA-C were A*24(02,03), A*11 (01,02), A*02(01,03,05-07,11): B*15(01,04-07,12,19,20), B*07(02-05), B*51(01-05)/B*52 (011,012); and Cw*07(01-03), Cw*04(01,02), Cw*08(01-03), respectively. The HLA class II alleles frequently found were DRB1*1202, DRB1*15021, DRB1*0701; DRB3*0301; DRB5* 0101; DQA1*0101, DQA1*0103, DQA1*0601; DQB1*0301, DQB1*0501, DQB1*0201; and DPB1*1301, DPB1*2301 and DPB1*0501. Two common HLA class I and II haplotypes with significant linkage disequilibrium were A*24 (02,03)-Cw*08 (01-03)-B*15 (01,04-07,12,19,20) -DRB1*1202 and A*33 (01,02)-Cw*0302-B*5801-DQB1*0201. The absence of B*27 and DRB1 *1401, the presence of A*2301 and high frequency of A*68 were observed in STM. Conclusion: Certain level of genetically distinction among STM, CT and NET existed. However, the genetic diversity of STM was relatively closer to CT than NET.

Increasing the chance to accept HLA-ABDR mismatched donor in kidney transplantation.

Two hundred and fifty-three kidney transplantations (KT) which included 68 (26.9%) living-related (L) and 185 (73.1%) cadaveric (C) KT with 0-6 HLA-ABDR mismatches (MM) were studied for the association of HLA-ABDR-MM specificities and the occurrence of graft rejection (GR). It was found that the incidence of acute and chronic rejection in CKT was significantly higher than that of LKT (42.1% vs 22.1%, p < 0.005). It was also observed that the number of ABDR-MM, AB-MM and BDR-MM which is important in GR were 2 times in CKT compared with LKT. The analysis revealed that HLA-A11, B16, B22, B35, B5, B17 and DR3 were good responders, whereas, HLA-A30, A2, B62, B18, B40, B44, B46 and DR10 were good stimulators for KT. GR were significantly increased with p < 0.01 and < 0.05, respectively. Specific HLA-MM specificities played a significant role in GR, i.e., some HLA-MM specificities were permissible, whereas, some were immunogenic. Careful selection of donor and recipient for KT by avoiding immunogenic HLA-MM and/or accepting permissible HLA-MM will improve graft survival and reduce the demand of kidney for retransplantation.