Search

Killer-cell immunoglobulin-like receptors (KIRs) play an important role in natural killer (NK) cell regulation. Interaction of KIRs with human leukocyte antigen (HLA) class I molecules can transmit signals to regulate the function of NK cells. In this study, the diversities of KIR genes and their ligands in 500 Thai blood donors were investigated. The coexistence of inhibitory KIRs (iKIR), activating KIRs (aKIR) and their ligands in the same individuals were also analyzed. Overall, 36 KIR genotypes were identified. The most common genotype was genotype AA1 (40.8%). All individuals carried at least one iKIR-HLA pair whereas 18% of the individuals lacked aKIR-HLA pair. The most common compound KIR-HLA profile was the presence of 3 iKIR-HLA pairs with 1 aKIR-HLA pair (21.4%). The most common compound gene profile of KIR-HLA pairs was the combined presence of KIR2DL3-C1, 3DL1-Bw4, 3DL2-A3/A11 and the full length KIR2DS4-its ligands (8%). This study provided a comprehensive analysis of the KIR-HLA profiles in Thai blood donors in regards to KIR genotypes, HLA ligands, KIR-HLA ligand pairs and compound gene profiles of both iKIRs and aKIRs and their ligands. These findings will be useful as baseline information for further studies in the associations of KIR genes and various diseases., (Copyright © 2016 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.)

Background: Human leukocyte antigen (HLA)-G is a nonclassical HLA class I molecule that displays strong immune-inhibitory properties and has been associated with allograft acceptance. However, there are conflicting data on the correlation of soluble HLA-G (sHLA-G) and acute rejection and no data on the correlation with acute tubular necrosis in kidney transplantation., Objective: To evaluate the association of sHLA-G level in early post-transplant period and allograft rejection/ and acute tubular necrosis (ATN) in kidney transplant recipients., Methods: The sera procured before transplantation and serially on day 3 and day 7 after transplantation from 76 kidney transplant recipients were analyzed for the level of sHLA-G by enzyme-linked immunosorbent assay., Results: The levels of sHLA-G from three serial sera did not differ between patients with acute rejection and patients without rejection. However, the sHLA-G levels on day 3 post-transplant and day 7 post-transplant in patients with ATN were significantly higher than that in patients without ATN (16.3 vs 9.85 U/ml, p = 0.018, for day 3 post-transplant and 12.47 vs 5.42 U/ml, p = 0.044, for day 7 post-transplant). In addition, the ROC analysis of sHLA-G for identifying patients with ATN showed that the area under curve was 0.67 (95% confidence interval 0.54-0.80)., Conclusions: There was no significant difference for sHLA-G levels between patients with acute rejection and without rejection. Interestingly, high levels of sHLA-G in day 3 and day 7 after transplantation were associated with acute tubular necrosis. Our findings raise the question whether the increased levels of sHLA-G in patients with acute tubular necrosis after transplantation might be a result of ischemia and reperfusion injury.

Background: The traditional method for assessing HLA antibodies in recipient serum samples is the complement-dependent cytotoxicity testing (CDC). Recently, the highly sensitive microbead-based Luminex assay was introduced and can detect low levels of anti-HLA Abs., Objective: To determine the impact of pretransplant donor-specific HLA antibodies (DSA) detectable by Luminex, despite a negative CDC crossmatch, on the outcomes of kidney transplantation. The correlation and cut-off value of panel reactive antibody (PRA) and DSA was also evaluated., Methods: Pre-transplant sera from 116 kidney transplant recipients with a negative CDC crossmatch were assessed for donor-specific HLA antibodies by using Luminex single antigen beads. The patients received kidney transplants at Ramathibodi Hospital between January 2003 and December 2007. The results were correlated with kidney graft outcomes., Results: DSA were found in 24.1% (28/116) of all recipients. Of the twenty-eight DSA positive patients, four developed antibody-mediated rejection (AMR) (4/28 = 14.3%). All these 4 patients had positive C4d staining in their biopsies. Of the eighty-eight DSA negative patients, two developed AMR (2/88 = 2.3%). The AMR occurred more frequently in the DSA positive group than in the DSA negative group (14.3% versus 2.3%. The patient and graft survival were similar in both groups. The strength of pre-transplant DSA was not associated with the incidence of rejection episodes., Conclusion: There was a higher incidence of AMR in patients with pre-transplant DSA despite a negative CDC crossmatch. However, pre-transplant DSA detected by Luminex had no statistically significant impact on delayed graft function, patient survival and graft survival.

Background: Killer cell Immunoglobulin-like Receptors (KIRs) are members of a group of molecules expressed on the surfaces of natural killer (NK) cells and some T cells. KIRs recognize MHC class I molecules on target cells. The interaction of these molecules regulates NK cell reactivity. The KIR gene cluster is highly polymorphic in individuals and different populations., Objective: Determine the frequencies and diversities of KIR genes among the Thai population., Results: Seventeen KIR genes and common subtypes were identified in 500 healthy Thai blood donors by PCR-SSP. The framework genes KIR2DL4, KIR3DL2, KIR3DL3, and KIR3DP1 were present in all individuals (100%). The observed frequencies of KIR genes vary in the presented population. The most frequent non-framework KIR gene was KIR2DLI (98.4%) while the least frequent was KIR2DL5B (24.2%)., Conclusion: It was observed that the Thai population shows polymorphism of the KIR genes and the diversities of KIR genes in Thai differed from other populations. These data might be of benefit to future studies of the KIR gene and its association with diseases.

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.

The Kidney Transplantation Program at Ramathibodi Hospital was established in 1985. By the end of 1998, there were 1,614 patients on the cumulative waiting list. The first kidney transplantation (KT) was started in 1986 by using kidney from living-related donor (LD) while cadaveric KT (CD-KT) was started in 1987. A total of 528 KT were done, 278 cases (52.7%) were CD-KT and 250 cases (47.3%) were LD-KT. Six patients had two kidney transplants. 278 kidneys were donated from 189 cadaveric donors. Fifty cadaveric donors (26.4%) were from Ramathibodi Hospital while the rest were from other hospitals and the Organ Donation Center, Thai Red Cross Society. For LD, 233 out of 250 (93.2%) were from living-related, more than 50 per cent of these donors were from siblings. 17 spousal donors have been accepted for KT at Ramathibodi Hospital since 1997. Concerning the recipient pools, 522 patients (32.3%) were transplanted, 123 patients (7.6%) died without KT, 111 patients (6.9%) underwent KT at other hospitals, and 78 patients (4.8%) changed to waiting lists at other hospitals. The rest were lost to follow-up. At present, only 265 patients are still actively waiting (send serum every month). The number of KT and living donors has gradually increased, whereas, the number of cadaveric donors has decreased. However, cooperation with the "Organ Donation Center" has improved the number of cadaveric donation in the last two years. Sufficient organ donations and an active working team will provide a good kidney transplant service for the patients.

Unlabelled: The HLA-A*02 subtyping in Thais was conducted and included in the 12th International Histocompatibility Workshop (12WS). A total of 81 randomized individuals previously serologically or DNA typed as A2 were studied for A2 subtypings. The subjects consisted of 32 Southern Thai-Muslims (STM) and 49 Central Thais (CT). The 12WS HLA-A*02 subtyping DNA typing kit was employed. The most common A*02 subtypes in STM were A*0203,*0201 and *0207 while they were A*0203, *0207 and *0201 in CT. A*0202, *0204, *0208, *0209, *0212, *0213, *0214, *0215, *0216 and *0217 were not found in both STM and CT. The 12WS data indicated that A*0201 was also the most frequent allele of A*2 among North-East Asians. A2 subtype study in 32 STM revealed that 2 in 8 of A*0201 showed the absence of bands at 813 bp and 705 bp with primer mix number 03A and 517A and weak reaction band with primer mix number 33A. In addition, 3 subjects with A*0201 variations have one nucleotide difference in exon 2 by sequence base typing (by MGJ. Tilanus) which will be reported separately., Conclusion: More variations of A*02 were observed among STM compared to CT. The variations of reactions with the set of primer mix should be carefully observed and subjected to further analysis.

Unlabelled: 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.

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.

Accelerated acute cellular rejection (AR) continues to be a serious problem in kidney transplantation (KT), suggesting that undetected presensitization may be encountered. The purpose of this study was to determine the most sensitive crossmatching (XM) technique to detect the preformed antibody (Ab) which may cause AR. One hundred and twenty two sera from 98 patients, on the waiting list for KT at Ramathibodi Hospital were XMed with 23 cadaveric splenic lymphocytes including 2 living related KT (LR-KT). The XM was performed by 3 different techniques namely, standard microlymphocytotoxicity test (standard NIH), antihuman globulin microlymphocytotoxicity test (AHG) and flow cytometric XM (FCXM). The XM results revealed that 8 out of 75 (10.7%) tests were negative by standard NIH, i.e., 5 tests were positive by AHG only and 1 test was positive by FCXM only and 2 tests were positive by both AHG and FCXM. In addition, the patients who had the AHG technique were not done, 5 out of 47 (10.7%) tests were also negative by standard NIH but were positive by FCXM. The sensitivity of the techniques was done by titrations of anti HLA-A2. It was found that FCXM was the most sensitive technique, followed by AHG and standard NIH, consecutively. In the retrospective study of LR-KT, case #1, the standard NIH for XM using pre-KT blood sample was negative while AHG and FCXM were strongly positive. The patient had AR at day 2 post-KT which confirmed by needle biopsy. The serum at day 11 and day 116 post-KT were tested again and were positive by the 3 techniques. Case #2, pre-KT blood sample showed negative T-XM by the 3 techniques while auto-B and B-XM were positive by standard NIH and AHG but negative by FCXM. This patient had rejection at day 16 after KT. The post-KT blood sample at day 30 showed positive auto T/B and T/B-XM by standard NIH and AHG whereas it was still negative by FCXM. It was also noted that Ab to donor B cell was better detected by standard NIH and AHG than FCXM. In conclusion, FCXM is more sensitive than standard NIH and AHG, however this technique is limited in detecting IgM T and B cell Ab. AHG technique can detect both IgG and IgM antidonor T and B cell Abs. In addition, AHG technique is more sensitive than standard NIH and does not require sophisticated equipment. AHG technique should be appropriate for routine XM, especially, in LR-KT and sensitized patients.

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.

Bone marrow transplantation (BMT) is one of the most effective procedures to cure the previously uncured hematologic diseases. However, it is costly and HLA typing to select the compatible donors contributed to its cost. A total of 53 prospective patients for BMT and their 114 siblings were analyzed to evaluate the use of locally prepared HLA-ABC common typing tray (ABCCT) during Mar 1988-Mar 1992. The 16, 9, 7, 5, 5 and 12 patients were diagnosed as aplastic anemia, CML, thalassemia, ALL, ANLL and other blood diseases, respectively. It was found that 18 patients were HLA-identical (HLA-ID) with one of their siblings except one patient had 2 HLA-ID sibs. All of those who appeared to be HLA-ID were further tested for the HLA-ABCDR typings. It was observed that 16 (88.89%) of 18 patients and 17 (89.47%) of 19 sibs were confirmed as HLA-ID. After careful clinical screening, only 13 HLA-ID pairs were able to proceed to the mixed lymphocyte culture and confirmed their status of HLA-ID by this test. Finally, only 6 (46.15%) of 13 patients received BMT with a high rate of success, ie all patients have survived with bone marrow engraftment. Thus, ABCCT is very useful for related BMT. It was highly efficient to exclude HLA-non-ID and haplo-ID yet the cost and workload were greatly reduced.