HLA-B*46:01:01:01 and HLA-DRB1*09:01:02:01 are associated with anti-rHuEPO-induced pure red cell aplasia

Treatment of anemia in patients with chronic kidney disease (CKD) with recombinant human erythropoietin (rHuEPO) can be disrupted by a severe complication, anti-rHuEPO-induced pure red cell aplasia (PRCA). Specific HLA genotypes may have played a role in the high incidence of PRCA in Thai patients (1.7/1,000 patient years vs. 0.03/10,000 patient years in Caucasians). We conducted a case-control study in 157 CKD patients with anti-rHuEPO-induced PRCA and 56 controls. The HLA typing was determined by sequencing using a highly accurate multiplex single-molecule, real-time, long-read sequencing platform. Four analytical models were deployed: Model 1 (additive: accounts for the number of alleles), Model 2 (dominant: accounts for only the presence or absence of alleles), Model 3 (adjusted additive with rHuEPO types) and Model 4 (adjusted dominant with rHuEPO types). HLA-B*46:01:01:01 and DRB1*09:01:02:01 were found to be independent risk markers for anti-rHuEPO-induced PRCA in all models [OR (95%CI), p-values for B*46:01:01:01: 4.58 (1.55-13.51), 0.006; 4.63 (1.56-13.75), 0.006; 5.72 (1.67-19.67), 0.006; and 5.81 (1.68-20.09), 0.005; for DRB1*09:01:02:01: 3.99 (1.28-12.49), 0.017, 4.50 (1.32-15.40), 0.016, 3.42 (1.09-10.74), 0.035, and 3.75 (1.08-13.07), 0.038, in Models 1-4, respectively. HLA-B*46:01:01:01 and DRB1*09:01:02:01 are susceptible alleles for anti-rHuEPO-induced PRCA. These findings support the role of HLA genotyping in helping to monitor patients receiving rHuEPO treatment.

Insights into the diversity of blood donation practice across Asia: How blood collection agencies adapt donor criteria and processes to their population

BACKGROUND AND OBJECTIVES

Securing an adequate blood supply relies on accurate knowledge of blood donors and donation practices. As published evidence on Asian populations is sparse, this study aims to gather up-to-date information on blood donors and donation practices in Asia to assist planning and strategy development.

MATERIALS AND METHODS

Ten blood collection agencies (BCAs) provided 12 months' data on donors who met eligibility criteria or were deferred, as well as details of their donation practices. Body mass index and blood volumes were calculated and analysed.

RESULTS

Data on 9,599,613 donations and 154,834 deferrals from six national and four regional BCAs revealed varied donation eligibility and collection practices. Seven used haemoglobin (Hb) criteria below the World Health Organization anaemia threshold. Seven accepted donors weighing <50 kg. Data collection on the weight and height of donors and on deferrals was inconsistent, often not routine. Deferred donors appear to weigh less, with corresponding lower estimated blood volume.

CONCLUSION

The diversity in eligibility criteria and donation practices reflects each BCA's strategy for balancing donor health with securing an adequate blood supply. Use of lower Hb criteria substantiate their appropriateness in Asia and indicate the need to define Hb reference intervals relevant to each population. We encourage routine gathering of donor weight and height data to enable blood volume estimation and local optimization of donation volumes. Blood volume estimation formulae specific for the Asian phenotype is needed. Information from this study would be useful for tailoring donation criteria of Asian donors around the world.

Anti-D alloimmunization by Asia type DEL red blood cell units in a D-negative Thai patient

BACKGROUND

DEL phenotype is a rare Rh variant that cannot be detected by routine serological typing, and DEL individuals are thus typed D-negative (D-). Anti-D alloimmunization has been reported in "true" D- patients receiving DEL red blood cells (RBCs).

CASE PRESENTATION

A 17-year-old, D- Thai male patient suffering from immunodeficiency syndrome with negative antibody screening received RBC units from 17 serological D- donors over a period of seven months due to acute respiratory failure with anemia. Before the 12th transfusion, anti-D production was detected. He was later transfused with RBCs from six other apparent D- donors. In order to elucidate anti-D production, all 17 blood donors were investigated by replicative serological testing and molecular analysis to identify potential RHD gene variants. All donors were confirmed D- by routine method, but as many as 12/17 were positive by adsorption-elution testing. Molecular analysis showed that five donors, including four whose blood was transfused before anti-D production occurred, carry the Asia type DEL allele, and are thus predicted to express a DEL phenotype. These data clearly suggest that 1/ the alloimmunized D- patient was exposed to D antigen, 2/ our adsorption-elution test is currently defective to identify DEL RBCs, and 3/ molecular analysis is highly valuable for Asia type DEL allele screening.

CONCLUSION

For the first time in Thailand, we report anti-D alloimmunization in a serological D- patient transfused by Asia type DEL RBC units. This work definitely supports the implementation of a dedicated policy for DEL blood management including molecular testing.

How do we translate gaps and unmet needs of blood management for thalassemia into a collaborative implementation framework?

BACKGROUND AND OBJECTIVE

The mainstay of management for thalassemia is regular blood transfusions. However, gaps and unmet needs of blood services for thalassemia are still not clearly identified and addressed in Thailand, a country prevalent with thalassemia. What can be a collaborative implementation framework that helps advance practices and policies relating to blood management for thalassemia?

METHODS

The first Blood & Beyond Roundtable Discussion was held in July 2022 to gather the current situation, gaps, and unmet needs of blood services for thalassemia from multidisciplinary experts and thalassemic patients. The Implementation Guide as suggested by the Centre for Effective Services was applied as a tool to consolidate information from the discussions and construct the collaborative implementation framework.

RESULTS

The National Blood Center and hospitals in Thailand followed the missions specified in the National Blood Policy and the standard guidelines to ensure the best practice of blood management for thalassemia. However, there were six gaps and unmet needs identified from the discussions. After all discussion points were mapped onto the framework, an implementation plan comprised of five specific activities became clear and actionable.

CONCLUSION

Without the complete information from both experts and patients, the implementation plan would not have been successfully constructed. The method that we employed to translate all information into the framework can be adapted by other countries to develop their own specific framework efficiently.

World human neutrophil antigens investigation survey

BACKGROUND AND OBJECTIVES

Human neutrophil antigens (HNAs) are categorized into five systems: HNA-1 to HNA-5. Given the importance of neutrophils in immunity, we sought to create awareness of the role of HNA diagnostic services in managing immune neutropenia and transfusion-related acute lung injury. To provide health communities all around the world with access to these services, we conducted a survey to create a directory of these HNA diagnostic services.

MATERIALS AND METHODS

An Excel table-based survey was created to capture information on the laboratory's location and was emailed to 55 individuals with known or possible HNA investigation activity. The collected data were then summarized and analysed.

RESULTS

Of contacted laboratories, the surveys were returned from 23 (38.2%) laboratories; 17 have already established HNA diagnostic (of them 12 were regular participants of the International Granulocyte Immunobiology Workshop [ISBT-IGIW]), 4 laboratories were in the process of establishing their HNA investigation and the remaining 2 responder laboratories, did not conduct HNA investigations. In established laboratories, investigation for autoimmune neutropenia (infancies and adults) was the most frequently requested, and antibodies against HNA-1a and HNA-1b were the most commonly detected.

CONCLUSION

The directory of survey respondents provides a resource for health professionals wanting to access HNA diagnostic services. The present study offers a comprehensive picture of HNA diagnostics (typing and serology), identifying weak points and areas for improvement for the first time. Identifying more laboratories involved in HNA diagnostics with limited access to international societies in the field will globally improve HNA diagnostics.

Dynamics of Cytokine, SARS-CoV-2-Specific IgG, and Neutralizing Antibody Levels in COVID-19 Patients Treated with Convalescent Plasma

Coronavirus disease 2019 (COVID-19) is a contagious illness worldwide. While guidelines for the treatment of COVID-19 have been established, the understanding of the relationship among neutralizing antibodies, cytokines, and the combined use of antiviral medications, steroid drugs, and convalescent plasma therapy remains limited. Here, we investigated the connection between the immunological response and the efficacy of convalescent plasma therapy in COVID-19 patients with moderate-to-severe pneumonia. The study included a retrospective analysis of 49 patients aged 35 to 57. We conducted clinical assessments to determine antibody levels, biochemical markers, and cytokine levels. Among the patients, 48 (98%) were discharged, while one died. We observed significantly higher levels of anti-nucleocapsid, anti-spike, and neutralizing antibodies on days 3, 7, and 14 after the transfusion compared to before treatment. Serum CRP and D-dimer levels varied significantly across these four time points. Moreover, convalescent plasma therapy demonstrated an immunoregulatory effect on cytokine parameters, with significant differences in IFN-β, IL-6, IL-10, and IFN-α levels observed at different sampling times. Evaluating the cytokine signature, along with standard clinical and laboratory parameters, may help to identify the onset of a cytokine storm in COVID-19 patients and determine the appropriate indication for anti-cytokine treatment.

Serologically D-negative blood donors in Thailand: molecular variants and diagnostic strategy

BACKGROUND

Discriminating individuals with "Asian type DEL" from those who are "true D-negative" (D-) among serologically D- donors/patients in Asia would be very valuable, as clinical outcomes are different in these groups. Here we investigated the molecular basis of D-negativity in Thai blood donors, designing a specific strategy for this purpose.

MATERIALS AND METHODS

After routine testing, a total of 1,270 serologically D- blood donors originating from Central, Northeastern and South Thailand underwent analysis of the RHD gene by (i) quantitative multiplex polymerase chain reaction of short fluorescent fragments (QMPSF); (ii) direct sequencing of exon 9 to identify the c.1227G>A variant defining the Asian type DEL allele; and (iii) direct sequencing of the other exons.

RESULTS

The most common observation was whole deletion of the gene (i.e. RHD*01N.01; allele frequency: 86.81%), followed by the Asian type DEL allele (RHD*01EL.01; 7.60%) and a D-negative hybrid allele (RHD*01N.03; 3.46%). Four novel alleles, including one with a 13.1 kilobase-deletion, were identified and characterized. All but one RHD*01EL.01 allele carriers (183/184) were C-positive (C+), suggesting that this latter subset may be screened specifically when investigating the c.1227G>A variant, which can be identified with 100% accuracy by a specific Tm-shift genotyping assay.

DISCUSSION

On the basis of our extensive molecular findings, we have designed a dedicated diagnostic strategy based on Rh C antigen typing followed by a genotyping test. Implementation of this method in all or selected groups of serologically D- donors/patients will contribute to improve the management of transfusion and pregnancy in Thailand.

Dynamics of Neutralizing Antibodies and Binding Antibodies to Domains of SARS-CoV-2 Spike Protein in COVID-19 Survivors

Neutralizing antibody level is used to predict immune protection against SARS-CoV-2 infection. Spike protein of SARS-CoV-2 is a major target for virus-neutralizing antibody. A number of neutralizing epitopes were mapped on receptor binding domain (RBD) and N-terminal domain (NTD) of S1 subunit of the spike. Anti-SARS-CoV-2 antibody usually decreases over time after recovery. Level of neutralizing antibody and binding antibody to several domains from COVID-19 recovered patients was observed longitudinally in this study. Sequentially collected serum samples from 35 patients demonstrated both similar and different trends of neutralizing antibodies versus binding antibodies to each domain. Twenty-three individuals showed similarly decreasing pattern of neutralizing titer, binding antibodies to RBD, NTD, fusion protein (S2), and nucleocapsid (NP). Interestingly, eight individuals had stably high neutralizing titer (≥320) for 3-12 months, whereas their binding antibodies to RBD, NTD, and NP rapidly decreased. Moreover, their binding antibodies to S2 were stable over time similar to the persistence of neutralizing antibody levels. The long-lasting antibody to S2 suggested an anamnestic response to cross-reactive epitopes from previous infections with other related coronaviruses. These data indicate a difference in kinetics and longevity of antibodies to various domains and epitopes of the SARS-CoV-2 proteins. A better understanding in this difference may help improve vaccine design to induce long-lasting immunity to COVID-19.

Impact of using genotyping to predict SERF negative phenotype in Thai blood donor populations

Background

SERF(+) is a high prevalence antigen in the Cromer blood group system that is encoded by a CROM*01.12 allele. The SERF(-) on red cells is caused by a single nucleotide variation, c.647C>T, in exon 5 of the Decay-accelerating factor,DAF gene. Alloanti-SERF was found in a pregnant Thai woman, and a SERF(-) individual was found among Thai blood donors. Since anti-SERF is commercially unavailable, this study aimed to develop appropriate genotyping methods for CROM*01.12 and CROM*01.-12 alleles and predict the SERF(-) phenotype in Thai blood donors.

Methods

DNA samples obtained from 1,580 central, 300 northern, and 427 southern Thai blood donors were genotyped for CROM*01.12 and CROM*01.-12 allele detection using in-house PCR with sequence-specific primer (PCR-SSP) confirmed by DNA sequencing.

Results

Validity of the PCR-SSP genotyping results agreed with DNA sequencing; CROM*01.12/CROM*01.12 was the most common (98.42%, 98.00%, and 98.59%), followed by CROM*01.12/CROM*01.-12 (1.58%, 2.00%, and 1.41%) among central, northern, and southern Thais, respectively. CROM*01.-12/CROM*01.-12 was not detected in all three populations. The alleles found in central Thais did not significantly differ from those found in northern and southern Thais.

Conclusion

This study is the first to distinguish the predicted SERF phenotypes from genotyping results obtained using in-house PCR-SSP, confirming that the CROM*01.-12 allele frequency ranged from 0.007 to 0.010 in three Thai populations. This helps identify the SERF(-) phenotype among donors and patients, ultimately preventing adverse transfusion reactions.

Common, intermediate and well-documented HLA alleles in world populations: CIWD version 3.0.0

A catalog of common, intermediate and well-documented (CIWD) HLA-A, -B, -C, -DRB1, -DRB3, -DRB4, -DRB5, -DQB1 and -DPB1 alleles has been compiled from over 8 million individuals using data from 20 unrelated hematopoietic stem cell volunteer donor registries. Individuals are divided into seven geographic/ancestral/ethnic groups and data are summarized for each group and for the total population. P (two-field) and G group assignments are divided into one of four frequency categories: common (≥1 in 10 000), intermediate (≥1 in 100 000), well-documented (≥5 occurrences) or not-CIWD. Overall 26% of alleles in IPD-IMGT/HLA version 3.31.0 at P group resolution fall into the three CIWD categories. The two-field catalog includes 18% (n = 545) common, 17% (n = 513) intermediate, and 65% (n = 1997) well-documented alleles. Full-field allele frequency data are provided but are limited in value by the variations in resolution used by the registries. A recommended CIWD list is based on the most frequent category in the total or any of the seven geographic/ancestral/ethnic groups. Data are also provided so users can compile a catalog specific to the population groups that they serve. Comparisons are made to three previous CWD reports representing more limited population groups. This catalog, CIWD version 3.0.0, is a step closer to the collection of global HLA frequencies and to a clearer view of HLA diversity in the human population as a whole.

Establishment of KEL*01 and KEL*02 Genotyping to Recruit Uncommon, Kell-positive, Reagent Red Cells Among Thai Blood Donors

BACKGROUND

The reagent red blood cells used to screen and identify antibodies have to include K+ cells in all batch productions. The data of K/k phenotypes among differing Thai blood donor populations remains unknown; hence, mass screening for uncommon K+ donors by serological test has some limitations. Implementing K/k genotyping may be useful to predict uncommon K+ donors to overcome this challenge. This study aimed to establish an in-house K/k genotyping technique and to report KEL*01 and KEL*02 allele frequencies among three Thai blood donor populations to increase the selection of K+ donors in rare blood group databases.

METHODS

A total of 2,239 DNA samples obtained from 1,512 central, 427 southern, and 300 northern Thai blood donors were included. The KEL*01 and KEL*02 genotyping using PCR with sequence-specific primers (PCR-SSP) was developed and validated. All samples were genotyped using developed PCR-SSP. Moreover, the possibility of finding group O and predicted K+ phenotypes among Thai blood donor populations was calculated.

RESULTS

The DNA controls were validated using two sets of primer combinations and the results of KEL*01 and KEL*02 genotyping were in agreement. The KEL*01 allele frequencies were 0.0007, 0.0047, and 0.0000, and KEL*02 allele frequencies were 0.9993, 0.9953, and 1.0000 among central, southern, and northern Thai donors, respectively. In addition, mass screening among 3,795 and 566 donors in central and southern Thai populations was required to find at least one group O and predicted K+ phenotypes.

CONCLUSIONS

The in-house PCR-SSP for KEL*01 and KEL*02 genotyping provided reproducible and accurate results with cost effectiveness. Our results confirmed the low KEL*01 allele frequencies among Thais. PCR-SSP could be used as an alternative technique to simply increase the number of uncommon predicted K+ phenotypes for reagent red blood cell recruitments.

Duffy blood group genotyping in Thai blood donors

Background

Duffy (FY) blood group genotyping is important in transfusion medicine because Duffy alloantibodies are associated with delayed hemolytic transfusion reactions and hemolytic disease of the fetus and newborn. In this study, FY allele frequencies in Thai blood donors were determined by in-house PCR with sequence-specific primers (PCR-SSP), and the probability of obtaining compatible blood for alloimmunized patients was assessed.

Methods

Five hundred blood samples from Thai blood donors of the National Blood Centre, Thai Red Cross Society, were included. Only 200 samples were tested with anti-Fy^a and anti-Fy^b using the gel technique. All 500 samples and four samples from a Guinea family with the Fy(a-b-) phenotype were genotyped by using PCR-SSP. Additionally, the probability of obtaining antigen-negative red blood cells (RBCs) for alloimmunized patients was calculated according to the estimated FY allele frequencies.

Results

The FY phenotyping and genotyping results were in 100% concordance. The allele frequencies of FY^*A and FY^*B in 500 central Thais were 0.962 (962/1,000) and 0.038 (38/1,000), respectively. Although the Fy(a-b-) phenotype was not observed in this study, FY^*B^ES/FY^*B^ES was identified by PCR-SSP in the Guinea family and was confirmed by DNA sequencing.

Conclusions

Our results confirm the high frequency of the FY^*A allele in the Thai population, similar to that of Asian populations. At least 500 Thai blood donors are needed to obtain two units of antigen-negative RBCs for the Fy(a-b+) phenotype.

Association between flow cytometric crossmatching and graft survival in Thai cadaveric-donor kidney transplantation

BACKGROUND

The flow cytometry cross-match (FCXM) technique is a sensitive method and has been reported to predict and protect graft rejection more efficiently than the conventional complement-dependent cytotoxicity cross-match (CDCXM) and the anti-human globulin-complement dependent cytotoxicity (AHG-CDC) methods.

METHODS

We performed retrospective FCXM in 270 cadaveric donor kidney transplant patients with negative CDC and AHG. The correlation between FCXM with graft rejection and graft survival within 1 year to 3 years was analysed.

RESULTS

There were 97 (35.9%) samples with positive FCXM. Only 7 (2.6%) of the 270 samples had evidence of antibody-mediated rejection (AMR) at the first year, which increased to 10 (3.7%) AMR samples after 3 years. Interestingly, there was a significant association between FCXM results with the graft outcome at 1 year (P = 0.046). However, when the association was analysed at 3 years after transplantation, it did not reach statistical significance. FCXM detected concordant positive results in 4 out of 8 samples. These samples had mean fluorescence intensity (MFI) of the donor-specific antibody (DSA) higher than 2,000. The DSA was identified by a single antigen bead.

CONCLUSION

Although positive FCXM, particularly for HLA class I, was significantly associated with graft loss from AMR within 1 year of transplantation in this study, there were a lot of FCXM false positives, as high as 35.9%. Additional studies are required to further assess the usefulness of FCXM in Thailand.

Genotyping confirms inheritance of the rare At(a-) type in a case of haemolytic disease of the newborn

The At(a) blood group antigen (now AUG2 in the Augustine system) is a high-frequency antigen with negative phenotype At(a-) found only in individuals of African ancestry. In a twin pregnancy, the fifth pregnancy in a woman of African origin, serological investigations confirmed that the mother was At(a-) and anti-At(a) was detected. DNA samples were exome sequenced and alignment was performed to allow variant calling. It was confirmed that the single nucleotide polymorphism, rs45458701, within the SLC29A1 gene encoding the ENT1 protein, recently reported to be a basis of the At(a-) phenotype was also the basis of the phenotype in this family. The reagents for serological analysis required to identify the rare blood type present in this mother are held in only a few reference laboratories worldwide. This case highlights the utility of genetic methods in resolving complex investigations involving blood grouping and demonstrates that genotyping of variants associated with blood types present in specific ethnic groups may be the fastest method available for identification of the basis of fetomaternal incompatibilities.

Comparison of a simple-probe real-time PCR and multiplex PCR techniques for HPA-1 to HPA-6 and HPA-15 genotyping

BACKGROUND

We aimed to compare HPA-1 to HPA-6 and HPA-15 genotyping results obtained by a simple-probe real-time polymerase chain reaction (PCR) technique with the multiplex PCR technique.

METHODS

Five hundred DNA samples from the Thai National Stem Cell Donor Registry (TSCDR) of the National Blood Centre, Thai Red Cross Society were included. Human platelet antigen (HPA) genotyping was performed by simple-probe real-time PCR and multiplex PCR techniques.

RESULTS

HPA-1, HPA-2, HPA-3, and HPA-4 genotyping results obtained by both techniques were in agreement. The misinterpretation of HPA-5, HPA-6, and HPA-15 genotypes was found in eight samples by simple-probe real-time PCR and HPA genotypes were confirmed by DNA sequencing. Two samples of HPA-5 were misinterpreted as HPA-5a5a instead of HPA-5a5b due to an NM_002203.3:c.1594A>C mutation (rs199808499) near the HPA-5 polymorphism (5' side). Five samples of HPA-6a6b were misinterpreted as HPA-6b6b because of an NM_000212.2:c.1545G>A mutation (rs4634) adjacent to the HPA-6 polymorphism (3' side). Interestingly, one sample of HPA-15a15b was misinterpreted as HPA-15b15b due to an NM_133493.1:c.2118C>A mutation near the HPA-15 polymorphism (3' side).

CONCLUSIONS

HPA genotyping results by two PCR techniques were compared. Incorrect assignments were found due to genetic variations near each HPA single nucleotide polymorphism. Therefore, to avoid false assignation, the use of two genotyping techniques is recommended.

Association of cytokine and cytokine receptor gene polymorphisms with the risk of chronic hepatitis B

BACKGROUND

Hepatitis B (HBV) infection is a major cause of chronic liver diseases, and the polymorphisms of cytokine genes may affect the progression of HBV-related hepatitis.

OBJECTIVE

The aim of this study was to examine the association of cytokine polymorphisms with the susceptibility to HBV-related chronicity.

METHODS

Specifically, a LIFECODES Cytokine SNP Typing kit was used to investigate 22 cytokine single nucleotide polymorphisms (SNPs) from 14 cytokine and cytokine receptor genes with the aim of analyzing the role of Th1 and Th2 genotype combination. This population-based case-control association study included 131 chronic HBV patients and a control group of 142 healthy donors.

RESULTS

When the combination of Th1 and Th2 genotypes was analyzed for the genetic risk factor for chronic hepatitis B, we did not observe any significant association. A non-significant association betweenTh1 and Th2 and this risk factor could have resulted from the limitation of our small sample size. When the results from each genotype were separately analyzed, the frequencies of the heterozygous CA (-592) and CT (-819) genotype of IL-10 gene-promoter polymorphisms were significantly higher in chronic HBV patients than that in healthy controls (OR=1.76, 9%CI =1.03-3.01, p =0.028; OR=1.79, 95%CI =1.04-3.06, p =0.024, respectively). Interestingly, the TCC (-1098/-590/-33) haplotype frequency of IL-4 showed a positive association with chronic hepatitis B as a protective haplotype (OR =0.53, 95%CI =0.32-0.85, p =0.005).

CONCLUSION

These preliminary results suggest that polymorphisms in some cytokine genes, particularly the Th2 cytokine, influence persistence of HBV infection.

Successful peripheral blood stem cell mobilization using pegfilgrastim in allogeneic stem cell transplantation

Pegfilgrastim is produced by binding a 20,000-dalton polyethylene glycol molecule to granulocyte colony-stimulating factor (G-CSF), increasing the mass of the compound, and resulting in a longer-lasting form of G-CSF. This makes it more convenient to use pegfilgrastim as a single-day injection. This study was a prospective phase II single-center trial. Fifteen normal related donors received pegfilgrastim 12 mg subcutaneously to mobilize peripheral blood stem cells (PBSC) for allogeneic stem cell transplantation. Leukapheresis was planned to start 3 days after injection. All harvests were successful. Median number of leukapheresis was 2 days (range 1-3 days). There were 7/15 donors who only required single leukapheresis. The maximum concentration of white blood cells (WBC) and circulating CD34 cells occurred 3 days after pegfilgrastim injection (WBC: median 62,200/μl; CD34: median 69.76/μl). The median yield of CD34 cells was 6.78 × 10(6)/kg recipient weight. The median CD3 cells was 1.89 × 10(8)/kg recipient weight. The main adverse events were bone pain and headache. Median neutrophil and platelet engraftments in the recipients occurred on day 12 and day 13, respectively, after transplantation. PBSC mobilization with single-day injection of pegfilgrastim in normal donor is feasible. Further comparisons of this protocol to standard G-CSF for allogeneic stem cell mobilization should be conducted in future.

Genomic characterisation of the Jk(a-b-) phenotype in Thai blood donors

BACKGROUND

The Kidd (JK) blood group antigens are encoded by the JK gene. The rare Jk(a-b-) phenotype can be caused by homozygosity for a silent JK allele. Currently, JK(null) alleles have been identified among different populations; however, information on its presence among Thais is not available.

MATERIALS AND METHODS

Screening for the Jk(a-b-) phenotype by the urea lysis test was performed in 25,340 blood samples from Thai blood donors. The Jk(a-b-) phenotypes were confirmed by an indirect antiglobulin test (IAT). Additionally, polymerase chain reaction amplification and sequence analysis of the JK gene were performed using previously described methods.

RESULTS

Five samples were confirmed as having a Jk(a-b-) phenotype by a urea lysis test and IAT; four of these samples were investigated. Two samples of JK*02 alleles were homozygous for a g>a mutation at the 3' acceptor splice site of intron 5 of the JK gene, as in previous studies in Asians and Polynesians. Moreover, one sample of JK*02 alleles was homozygous for an 896G>A mutation at exon 9 (Gly299Glu), as in a previous study in Polynesians. Interestingly, missense dual mutations of JK*01 alleles from a female blood donor were identified. The first mutation was 956C>T (Thr319Met) in exon 10, as in a recent study in African-Americans. The second mutation was 130G>A (Glu44Lys) at exon 4, as in previous studies among Caucasians.

CONCLUSION

There are various different molecular bases of the Jk(a-b-) phenotype. This is the first report of JK(null) alleles among Thais. The information presented in this study could be beneficial in planning genotyping strategies for blood donors and patients.

A nested sequence-specific primer-polymerase chain reaction for the detection of HLA-B*15:02

In this study, we reported a new technique in detecting HLA-B*15:02 by using a nested sequence-specific primer-polymerase chain reaction (SSP-PCR) that can be used on genomic DNA and whole blood for carbamazepine hypersensitivity prediction. We tested a total of 200 blind samples with known human leukocyte antigen (HLA)-B allelic types (44 positive for HLA-B*15:02 and 156 negative for HLA-B*15:02) with this new nested SSP-PCR technique and compared its efficacy to that of commercial sequence-specific oligonucleotide probe-polymerase chain reaction (SSOP-PCR). Using starting materials from DNA and whole blood, we were able to detect HLA-B*15:02 in 44 of our samples correctly. The test is very sensitive and is highly reproducible.

Intra-coronary bone marrow mononuclear cell transplantation in patients with ST-elevation myocardial infarction: a randomized controlled study

BACKGROUND

Stem cell transplantation is a potential treatment to improve left ventricular ejection fraction (LVEF) after ST elevation myocardial infarction (STEMI). However, the outcomes still are controversial.

OBJECTIVE

To determine the 6-month LVEF of the patients who underwent intra-coronary bone marrow mononuclear cell (BMC) transplantation in patients with STEMI compared with controlled subjects.

MATERIAL AND METHOD

After successful percutaneous coronary intervention (PCI) in STEMI patients who had LVEF was less than 50% were randomized to intra-coronary BMC transplantation or control. Bone marrow aspiration of 100 cc was performed in the morning. After cellprocessing for three hours, the suspension of BMC about 10 cc were infused to infracted area using standard PCI technique. Balloon occlusion for three minutes was performed during cell infusion. Cardiac magnetic resonance imaging was used to determine LVEF scar volume and LV volume before and six-month follow-up.

RESULTS

Between September 2006 and July 2008, 23patients (11 in BMC group and 12 in control group) were enrolled. Mean BMC count before transplant was 420 x 10(6) cell with 96% viability. At six-month follow-up, New York Heart Association function class significantly improved in both groups (2.3 +/- 0.6 to 1.2 +/- 0. 4 for BMC and 2.3 +/- 0.7 to 1.3 +/- 0.5 for control group) but no difference was seen between groups. However, scar volume, wall motion score index, and LVEF did not show improvement after six months in both groups (33.7 +/- 7.7 to 33.5 +/- 7.6 for BMC and 31.1 +/- 7.1 to 32.6 +/- 8.3 for control group). No complication was observed during the procedure.

CONCLUSION

BMC transplantation intra-coronary in patients with STEMI in KCMH was feasible and safe but LVEF improvement could not be demonstrated.

Distribution of cytokine gene polymorphisms in Thai population

The distribution of 21 cytokine polymorphisms within 13 cytokine and cytokine receptor genes was analyzed in 102 healthy Thai individuals using the LIFECODES Cytokine SNP Typing kit. The TGFB codon25 marker is monomorphic in the Thai population. The IL1B+3962, IL6-174, and TNFA-238 are very rare polymorphisms, with only 0.01-0.04 minor allele frequency (MAF). The IL4-1098, IL1A-889, and IL10-1082 are found only 0.06-0.08 in Thai. Other cytokine polymorphisms (IL1B-511, IL1R pst1 1970, IL1RN mspa1 11100, IL4RA+1902, IL12B-1188, IFNG+874, TGFB codon10, TNFA-308, IL2-330, IL2+166, IL4-590, IL4-33, IL10-819, and IL10-592) in Thai have MAFs more than 0.10, ranging between 0.13 and 0.47. When comparing the allele and genotype frequencies with public single nucleotide polymorphism (SNP) database, most cytokine polymorphisms in Thai show similar distribution to Han Chinese and Japanese, but significantly different from Caucasian and African populations. Only a few markers, including IL4A+1902, TNFA-308, IL1B+3962, and IL2+166 show statistically different distribution among Thai and other Asian populations especially with the Japanese.

Jk(a-b-) phenotype screening by the urea lysis test in Thai blood donors

BACKGROUND

The Jk(a-b-) phenotype is rare in most populations and often detected after transfusion or pregnancy. After immunisation, anti-Jk3 forms and it can be difficult to find compatible Jk(a-b-) donors. Using anti-Jk(a) and anti-Jk(b) in a conventional tube method is unsuitable for identifying Jk(a-b-) in mass screening of blood donors. Jk(a-b-) phenotypes are associated with the absence of urea transporters on erythrocytes, making red blood cells (RBC) resistant to lysis by 2M urea, while Jk(a+b-), Jk(a-b+) and Jk(a+b+) phenotypes are susceptible to lysis.

MATERIALS AND METHODS

We screened for Jk(a-b-) phenotypes in blood donors by the urea lysis test using a 96-well microplate. The Jk(a-b-) phenotypes were confirmed by the indirect antiglobulin test (IAT).

RESULTS

Altogether, 20,163 blood samples from Thai blood donors were tested and only RBC from five samples were resistant to lysis by 2M urea, while 20,158 samples were completely lysed within 5 min. In an IAT, both anti-Jk(a) and anti-Jk(b) failed to agglutinate RBC from all five samples. Using a micro-titre plate, the direct urea lysis test, costs * 0.01, about 480 times less than IAT. Moreover, the test time for each plate (94 samples) is about 18 times less than that for IAT.

CONCLUSION

Jk(a-b-) phenotype screening by the direct urea lysis test on samples in a micro-titre plate is simple, cost-effective and practical for mass screening of blood donors.

14th International HLA and Immunogenetics Workshop: Report on the Prospective Chronic Rejection Project

An international collaborative study of 45 transplant centers was undertaken at the 14th International HLA (human leukocyte antigen) and Immunogenetics Workshop to see if HLA antibodies detected posttransplant are predictive of chronic graft failure. With the newly developed assay, MICA (major histocompatibility complex class I-related chain A) antibodies were also measured and their effect analyzed. Total of 5219 sera from patients who were more than 6 months posttransplant with functioning graft were tested for HLA antibodies by enzyme-linked immunosorbent assay, flow cytometry, or Luminex. HLA antibodies were found in 27.2% of kidney patients, 23.6% in the liver, 52.7% in the heart, and 21.7% in the lung. The method of antibody testing did not have a marked influence on the frequency of antibodies detected. MICA antibodies were detected in 15% of kidney patients, 30% of heart patients, and 31% of liver patients. Among 948 kidney patients who had HLA antibodies, 7.3% had rejected their graft within 1 year of testing, compared with 1.7% in 2615 patients without HLA antibodies (P= 0.8 x 10(-17)). Death occurred in 1.4% of total kidney patients and did not correlate to the presence of antibodies. We conclude that patients with posttransplant HLA antibodies indeed have a higher rate of chronic graft failure and that posttransplant antibodies are predictive of chronic rejection.

14th International HLA and Immunogenetics Workshop Prospective Chronic Rejection Project: a three-year follow-up analysis

The three-year follow-up of 4,144 patients of the 14th International Workshop Prospective Chronic Rejection study has reinforced the evidence that post-transplant HLA antibodies are predictive of long-term graft loss. Three years after a single testing for HLA antibodies, 10% of kidney recipients who were antibody-positive had lost their grafts, in contrast to only 5% of antibody-negative patients (p<0.0001). The adverse effect of post-transplant antibodies on graft survival was also observed in lung, heart, and liver transplants. Donor-specific antibodies and 'strong' non-DSA had stronger association with graft loss than 'moderate' non-DSA. Periodic antibody monitoring, combined with specificity and strength analysis, would help in the early identification of allograft recipients who are at high risk of graft failure.

Outcome of pediatric hematopoietic stem cell transplantations from Thai unrelated donors matched with high-resolution HLA typing

The authors evaluated the outcome of ten children given hematopoietic stem cell transplantations from Thai unrelated donors (URD-HSCT) selected using DNA high-resolution typing of both HLA class I and II loci. Six patient/donor pairs (60%) were fully matched; four (40%) were 5/6 matched. Patients had either non-malignant (n=9) or malignant (n=1) diseases. In most cases, graft-versus-host disease (GVHD) prophylaxis composed of cyclosporine and short-term methotrexate. The probability of hematopoietic recovery at day 30 was 90%. The cumulative probability of acute GVHD and of chronic GVHD equaled 44.4 and 0%, respectively. Three patients died of transplant-related complications. The probability of transplant-related mortality (TRM) at 30, 100, and 180 days were 10, 30, and 30%, respectively. The overall and disease-free survival rates were 70 and 70%, respectively. URD-HSCT with donor selection based on high-resolution HLA typing is associated with a low incidence of both severe acute GVHD and graft failure. The observed outcome is comparable to that of children transplanted from HLA-identical siblings.

Gene frequencies of the HPA-1 to 6 and Gov human platelet antigens in Thai blood donors

Human platelet alloantigens (HPA) are important in neonatal alloimmune thrombocytopenia (NAIT), posttransfusion purpura (PTP), platelet transfusion refractoriness, passive alloimmune thrombocytopenia, and transplantation-associated alloimmune thrombocytopenia. Thus, HPA genotyping is essential in diagnosis and treatment. We analyzed HPA-1 to 6 and Gov alleles, using PCR with sequence specific primers (PCR-SSP) in 500 Thai blood donors who had been HLA class I antigen typed. HPA-4a was present in all samples. HPA-1b, -2b, -5b, and -6b were rare, and HPA-4b was not found. HPA-3a and -3b showed frequencies of 56.0 percent and 44.0 percent, respectively. Gova and Govb showed frequencies of 49.1 percent and 50.9 percent, respectively. The prevalence rates of HPA-1 to 6 gene frequencies (GFs) were consistent with those of other Asian populations rather than those of Caucasians. We also report on the GFs of Gova and Govb, which also are comparable to those of Asian populations. Our results could establish a useful HPA- and HLA-matched plateletpheresis donor file and provide an improvement of platelet alloantibody detection in alloimmune thrombocytopenic patients, and, therefore, a more effective platelet transfusion program.

Umbilical cord blood transplantation in children with beta-thalassemia diseases

To evaluate factors affecting the outcome of sibling and unrelated donor umbilical cord blood transplantation (CBT) in Thai children with beta-thalassemia diseases. The case-series study of all children undergoing such transplants in our institute was conducted Six children with thalassemia major were diagnosed at a median age of 1.5 years and CBT was performed at a median age of 5.5 years (range 2-15). Six donors consisted of three HLA-identical siblings, one two-allele, one three-antigen mismatched sibling, and one one-allele mismatched unrelated cord blood. The median number of nucleated cells infused was 2.83 x 10(7)/kg (range 1.49-5.3); the median number of CD34+ cells infused was 1.94 x 10(5)/kg (range 0.2-5.3). In all, two patients had complete donor engraftment; three had mixed chimerism (MC); one patient died of cerebral thrombosis and neutropenic septicemia. Of the two complete donor-engrafted patients, two developed grade 2 acute graft-versus-host disease (GVHD) which responded well to immunosuppressive therapy. Of the three mixed-chimeric patients, two were clinically cured. With a median follow-up of 7 months (range 2-30), five children survived and have done well with transfusion-independent. Umbilical cord blood provides a reasonable option for hematopoietic stem cell source to transplant for beta-thalassemia diseases and the outcome in the present study was good.

Monitoring of T-cell subsets in patients treated with anti-CD 25 antibody

Daclizumab and basiliximab, the antibodies to the interleukin-2 receptor (anti-IL-2R), decrease the incidence of acute rejection in renal transplantation. However, prolonged blockade of IL-2 receptor (IL-2R:CD25) may hamper apoptosis of reactive T-cell clones and thus may obstruct tolerance induction. We determined the effect of varying doses of anti-IL-2R on the number of CD3+CD25+ cells as an index of CD 25 blockade. The number of CD3+CD25+ cells was determined in four groups of induction therapies: no antibody induction; two doses of 50 or 25 mg daclizumab on day 0 and day 14; and two doses of 20 mg basiliximab at day 0 and day 4 (n=10, 24, 10, and 10, respectively). The number of CD3+CD25+ cells were monitored in whole blood before antibody infusion as well as 24 hours thereafter and weekly after transplantation. With two doses of 50 mg daclizumab, two doses of 25 mg daclizumab, and two doses of 20 mg basiliximab, the expression of CD3+CD25+ cells was completely suppressed for 12, 10, and 12 weeks posttransplantation, respectively. The reappearance of CD3+CD25+ cells above the baseline for each induction regimen was: 17 weeks for two doses of 50 mg daclizumab, 11 weeks for two doses of 25 mg daclizumab, and 13 weeks for two doses of 20 mg basiliximab. Monitoring of CD3+CD25+ cells may be utilized to tailor anti-IL-2R administration at a minimal dosage, yet retaining adequate IL-2R blockade for at least 3 months posttransplantation.

Cord blood collection for the National Cord Blood Bank in Thailand

Umbilical cord blood is an effective alternative source of hematopoietic stem cells transplantation in children and adolescents. However, the efficacy and safety of cord blood transplantation correlates with the quantity and quality of cord blood. To evaluate the collection systems and processing of cord blood donations, a pilot research program to optimize recruitment, collection and processing of cord blood donations was developed. The present results showed that the quality of the cord blood (volume, total white blood cells (WBC) count, CD34+ and sterility control) collected was satisfactory and discard rate of collecting units (24.2%) were comparable with data reported from other cord blood banks. To find the optimal mode of collection, comparison of 3 cord blood collection methods (Method 1 = Hanging method after delivering the placenta, Method 2 = Aspiration from in utero placenta, Method 3 = Aspiration from in utero placenta and Syringe-assisted aspiration) using the closed system showed that method 3 was the best method but it required more trained personnel and involved a complicated procedure. The National Cord Blood Bank started its activity in 2002 after several years of pre-clinical studies. To date, a number of transplants using cord blood from related and unrelated cord blood (first report in Thailand) donors have been successfully performed.

Neonatal alloimmune thrombocytopenia due to anti-Nak(a)

BACKGROUND

The accurate diagnosis of neonatal alloimmune thrombocytopenia is essential in the effective treatment of potentially serious bleeding in neonates.

CASE REPORT

Reported here is a case of a full-term female baby who was delivered by vacuum extraction from a gravida 1 para 1 healthy mother. She presented with generalized petechiae and bilateral cephalhematoma, which she had had since birth. At 7 hours of life, she had an upper gastrointestinal hemorrhage and was found to have severe anemia and marked thrombo-cytopenia. Coagulation screening tests were normal. The diagnosis of neonatal alloimmune thrombocytopenia was suspected, and maternal serum was collected for further study. The baby was treated with a single dose of hydrocortisone (10 mg/kg) and IVIG (400 mg/kg) while waiting for irradiated platelets from her mother. After 30 mL of a transfusion of maternal platelets, the baby's platelet count rose dramatically, from 15,000 to 162,000 per microL, and it remained stable at that level. She was discharged on the 10th hospital day in good condition. During the follow-up period of 8 months, her growth and development were satisfactorily normal, as well as her platelet count. A high-titered platelet antibody was detected in the maternal serum by use of a solid phase platelet adherence technique.

RESULTS

The specificity of the platelet antibody was identified as anti-Nak(a) by the mixed passive hemagglutination test method.

CONCLUSION

These findings suggested a diagnosis of NAIT caused by anti-Nak(a).

The effects of cigarette smoking on peripheral blood leukocytes and lymphocyte subpopulations: an urban population-based study in Thailand

Preliminary studies for peripheral blood leukocytes and lymphocyte subsets were done in smokers and non-smokers. There were 20 smokers (smoked more than 10 cigarettes per day) for more than a year and 20 non-smokers (smoked less than 20 cigarettes/20 years). Ages of smokers and non-smokers were respectively 21-57, and 18-55 years. Cigarette smoking was associated with a statistically significant increase in the number of neutrophils, activated lymphocytes, CD25 and CD19; but a statistical decrease in the percentage of CD7 and CD3. (P < 0.05)

Comparative analysis of serological and molecular results for HLA-DR typing in 120 Thai subjects

In this study, serological HLA-DR typing results were compared to typing results obtained with sequence-specific primers in the polymerase chain reaction (PCR-SSP). HLA-DR typing was performed on 120 random Thai individuals. Differences in HLA-DR typing results were found in 18 out of 120, which were due to cross reactive antibodies and the lack of potent antisera to define proper HLA-DR splits by serology. Furthermore, PCR-SSP is fast and easy to perform as HLA-DR typing results can be obtained within 2 hours. From the results of this study it can be concluded that PCR-SSP is a reliable and promising technique for HLA-DR typing which can replace the serological technique in routine clinical practice.