Production of recombinant humanized monoclonal anti-human neutrophil antigen (HNA) antibodies with potential applicability as standard antibodies.

BACKGROUND: Antibodies against human neutrophil antigen (HNA) are involved in the pathogenesis of neonatal alloimmune neutropenia, autoimmune neutropenia, and transfusion-related acute lung injury. The present methods for anti-HNA antibody identification strongly depend on the presence of standard antisera with known allo/isospecificities. Here, we aimed to produce recombinant humanized antibodies to HNA from available mouse monoclonal antibodies (MoAbs). STUDY DESIGN AND METHODS: RNAs were extracted from available hybridoma cells producing mouse anti-HNA antibodies recognizing HNA-1a (TAG-1), -1b (TAG-2), -2 (TAG-4), and FcγRIIIb, and the cDNA was synthesized. Recombinant fragments consisting of the variable regions of the H and L chains of the mouse MoAb ligated to the constant region of human IgG were incorporated into an expression vector and transfected into CHO cells. Antibody specificity of the selected humanized monoclonal antibodies was confirmed, and tested by the participants of the ISBT Granulocyte Immunobiology Working Party (GIWP) workshop 2020. RESULTS: GIFT results confirmed the specific reactivity of TAGH-1 to -4, except for a cross-reactivity of TAGH-2 with HNA-1a/a neutrophils, only in flow-cytometry. MAIGA results showed clear specificity of all humanized antibodies, but the selection of the appropriate capture monoclonal antibody was essential for the test. The results of the ISBT GIWP showed high concordance among the labs. CONCLUSIONS: These are the first humanized monoclonal antibodies to HNA-1 and HNA-2 antigens produced and they will be important standard reagents for laboratories testing for neutrophil antibodies. We plan to have these humanized MoAbs available through WHO.

A novel reagent for the screening of haptoglobin-deficient blood donors.

BACKGROUND AND OBJECTIVES: In Japan, the prevalence of haptoglobin deficiency is approximately 1 in 4000. Haptoglobin-deficient individuals may produce anti-haptoglobin from allo-immunization, leading to serious transfusion reactions. Therefore, implementation of a consistent supply of haptoglobin-deficient fresh frozen plasma is crucial. We developed a novel reagent to facilitate large-scale identification of haptoglobin-deficient individuals as potential donors of plasma products. MATERIALS AND METHODS: We established mouse monoclonal anti-haptoglobin-producing cell lines (three clones) using the hybridoma method by immunizing mice with the haptoglobin protein. Purified antibodies were conjugated with carboxylate-modified polystyrene latex beads and used for haptoglobin measurements by the latex agglutination method using an automatic analyser (LABOSPECT008). Samples with low protein concentrations were re-examined by enzyme-linked immunosorbent assay to confirm the results. Additionally, the haptoglobin gene was amplified by polymerase chain reaction to confirm the haptoglobin deletion allele (Hpdel ). RESULTS: From February to October 2022, 7476 blood donor samples were screened. Two haptoglobin-deficient and 21 low-haptoglobin-expressing individuals were identified. Two haptoglobin-deficient donors were found homozygous for Hpdel , and 19 (90%) of the 21 low-haptoglobin-expressing individuals were heterozygous for Hpdel , which includes the first reported case of heterozygous Hpdel /HpJohnson . CONCLUSION: We developed a new reagent for the detection of haptoglobin deficiency, which is automatable and inexpensive and appears useful for large-scale screening of blood donors.

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.

Decreased rate of blood donors with high ABO antibody titers in Japan and the underlying factors: Comparisons between 2010 and 2021.

BACKGROUND AND OBJECTIVES: Previously (2007), it was reported that ABO antibody titers in Japanese blood donors had decreased significantly compared to 20 years before. Here we evaluated whether further decrease of antibody titers had occurred in recent years, and the potential factors associated with changes in antibody titers. MATERIALS AND METHODS: Serum/plasma from random blood donors in 2010 and 2021 (2010: 3369, 2021: 5796 donors) was classified into low, middle, and high ABO antibody titers according to the reactivity of diluted serum/plasma (2.5-fold and 20-fold) by an automated microplate system. The rates of low/high titer in the two periods were compared. Logistic regression and age-gender-BMI subgroup analyses were conducted to identify the factors that contributed to changes in antibody titers. RESULTS: Compared to 2010, the rate of donors with high ABO antibody titers was　decreased in 2021 for both anti-A and anti-B (anti-A, 2010: 23.8%, 2021: 19.3%; anti-B, 2010: 23.8%, 2021: 16.4%). In logistic regression analysis, age was found to significantly affect both anti-A and anti-B antibody titers (anti-A, adjusted odds ratio 0.36, 95% CI 0.31-0.41; anti-B, 0.42, 0.37-0.47), and BMI (0.82, 0.73-0.92) and other time-related factors (0.79, 0.71-0.88) significantly affect anti-B antibody titers. Subgroup analysis revealed decreased rate of high anti-B titers in the higher age group in 2021. CONCLUSION: The rate of high ABO antibody titers, especially high anti-B titers, was significantly decreased in 2021, and our results suggested an association with aging and obesity of blood donors as well as other time-related factors.

Efficacy of convalescent plasma therapy for COVID-19 in Japan: An open-label, randomized, controlled trial.

BACKGROUND: Convalescent plasma is a potential therapeutic option for patients with coronavirus disease 2019 (COVID-19). Despite its use for treating several viral infections, we lack comprehensive data on its efficacy against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). METHODS: We conducted a multicenter, open-label, randomized controlled trial of convalescent plasma therapy with high neutralizing activity against SARS-CoV-2 in high-risk patients within five days after the onset of COVID-19 symptoms. The primary endpoint was the time-weighted average change in the SARS-CoV-2 viral load in nasopharyngeal swabs from days 0-5. RESULTS: Between February 24, 2021, and November 30, 2021, 25 patients were randomly assigned to either convalescent plasma (n = 14) or standard of care (n = 11) groups. Four patients discontinued their allocated convalescent plasma, and 21 were included in the modified intention-to-treat analysis. The median interval between the symptom onset and plasma administration was 4.5 days (interquartile range, 3-5 days). The primary outcome of the time-weighted average change in the SARS-CoV-2 viral load in nasopharyngeal swabs did not significantly differ between days 0-5 (1.2 log10 copies/mL in the convalescent plasma vs. 1.2 log10 copies/mL in the standard of care (effect estimate, 0.0 [95% confidence interval, -0.8-0.7]; P = 0.94)). No deaths were observed in either group. CONCLUSIONS: The early administration of convalescent plasma with high neutralizing activity did not contribute to a decrease in the viral load within five days compared with the standard of care alone.

Genetic background of anti-Xga producers in Japanese blood donors.

BACKGROUND AND OBJECTIVES: The Xg blood group is composed of two antigens, Xga (XG1) and CD99 (XG2 and MIC2). The XG and CD99 are homologous genes located on pseudoautosomal region 1 of the X and Y chromosomes. The expressions of Xga and CD99 are co-regulated by a single nucleotide polymorphism (rs311103) in the GATA-1 binding region. Another mechanism of the Xg(a-) phenotype is the genomic deletion of approximately 114 kb, including the XG gene. Anti-Xga seems to be naturally occurring by detection in males who have never been transfused. MATERIALS AND METHODS: In this study, we identified 23 anti-Xga producers among 580,115 donors (0.004%). Additional 12 anti-Xga producers were also identified from a separate cohort. RESULTS: All 35 anti-Xga producers were male. Genomic DNA was obtained from 34 of 35 producers, and all 34 producers were confirmed to carry the XG-gene-deficient allele (XGdel). The breakpoints of all 34 producers were identical. The XGdel was also identified in 12 non-producers of anti-Xga among 860 donors who have no antibodies against RBCs, and the breakpoints were also identical with the anti-Xga producers. CONCLUSION: Our results will serve as the basis for a more complete understanding of Xg blood group polymorphisms.

Frequencies of glycophorin variants and alloantibodies against Hil and MINY antigens in Japanese.

BACKGROUND AND OBJECTIVES: Antigens of the MNS blood group system are expressed on the red blood cell (RBC) membrane on glycophorin A (GPA) and glycophorin B (GPB) or on hybrid molecules of GPA and GPB. This study investigated the distribution of glycophorin variants and alloantibodies against Hil and MINY among Japanese individuals. METHODS: Mi(a+) or Hil+ RBCs were screened using an automated blood grouping machine (PK7300) with monoclonal anti-Mia or polyclonal anti-Hil. Glycophorin variants were defined by serology with monoclonal antibodies against Mia , Vw, MUT and Mur, and polyclonal antibodies against Hil, MINY and Hop + Nob (KIPP). The glycophorin variants were further confirmed by immunoblotting and Sanger sequencing. Alloanti-Hil and alloanti-MINY in the plasma were screened using GP.Hil RBCs in an antiglobulin test. The specificity of anti-Hil or anti-MINY was assessed using GP.Hil (Hil+MINY+) and GP.JL (Hil-MINY+) RBCs. RESULTS: The GP.HF, GP.Mur, GP.Hut, GP.Vw, GP.Kip and GP.Bun frequencies in 1 005 594 individuals were 0·0357%, 0·0256%, 0·0181%, 0·0017%, 0·0009% and 0·0007%, respectively. GP.Hil was found in as four of the 13 546 individuals (0·0295%). Of 137 370 donors, 10 had anti-Hil (0·0073%) and three had anti-MINY (0·0022%). CONCLUSIONS: Glycophorin variants were relatively rare in Japanese individuals, with the major variants being GP.HF (0·0357%), GP.Hil (0·0295%) and GP.Mur (0·0256%). Only one example of anti-MINY was previously reported, but we found three more in this study.

A case of Philadelphia chromosome-positive acute lymphocytic leukaemia with type I CD36 deficiency.

BACKGROUND: CD36 is a glycoprotein expressed on platelets and monocytes of the blood. There are two types of CD36 deficiency, type I and type II. Individuals with type I-deficiency do not express CD36 in any cell type and can produce the CD36 antibody, which causes pathological conditions, such as fetal/neonatal alloimmune thrombocytopenia (FNAIT) and platelet transfusion refractory (PTR), through antigenic exposure via transfusion or pregnancy. CASE PRESENTATION: We experienced a case of Philadelphia-positive acute lymphoblastic leukaemia with PTR. In addition to the CD36 antibody, multiple-specificity HLA antibodies were present in the patient's plasma, requiring transfusion of HLA-compatible and CD36-negative platelets (PC-HLA). Since the number of donors was limited, it was necessary to set-up a blood transfusion schedule so that hyper-fractionated cyclophosphamide, vincristine and doxorubicin therapy (hyper-CVAD) and ponatinib combination chemotherapy could be safely administered to achieve molecular remission. Rituximab administration resulted in reduced levels of both CD36 antibody and HLA antibody. Given the expression of CD36 on haematopoietic stem cells and the limited availability of CD36-negative PC-HLA, haematopoietic stem cell transplantation (HSCT) was not considered to be an option. CONCLUSION: If CD36-negative, allogeneic haematopoietic stem cell donors are unable to be found, the indications for HSCT in patients with type I CD36-deficiency should be carefully weighed. In the present case, molecular remission has been able to be maintained to the present day after completion of a two-year maintenance regimen.

GP.MOT: A novel glycophorin variant identified in a Japanese blood donor.

BACKGROUND: In this study, we identified a novel glycophorin variant (GP.MOT) in a Mia -positive Japanese blood donor. The proband with this glycophorin variant was discovered by antigen screening of samples from 475,493 Japanese blood donors using monoclonal anti-Mia . STUDY DESIGN AND METHODS: Standard serological techniques and flow cytometry were performed. GP.MOT RBCs were examined by immunoblotting using anti-GPA, anti-MUT or anti-Mur. Genome DNA was extracted from whole blood, and the GYPA/GYPB was analyzed by polymerase chain reactions and Sanger sequencing. RESULTS: The MNS blood group of the proband was M + N + w S-s + with the presence of other low-frequency antigens including Mia , Mur, MUT, and KIPP. A 43-kDa molecule, which is almost equivalent in size to glycophorin A (GPA), was identified by immunoblotting using monoclonal anti-MUT and anti-Mur. Sanger sequencing clearly indicated that the proband had two different GYPA*M alleles at SNP rs62334651 (GYPA*M232 + 55A and GYPA*M232 + 55G), as well as a GYP(B-A) hybrid allele (GYP*MOT) with breakpoints located on pseudoexon 3 of GYPB from c.210 to c.219. DISCUSSION: We identified a hybrid glycophorin GP.MOT with the deduced unique amino acid sequence GPB (20-45)-GPΨB (46-70)-GPA (71-149), which has not been previously reported.

An international comparison of HIV prevalence and incidence in blood donors and general population: a BEST Collaborative study.

BACKGROUND AND OBJECTIVES: Efficiency in mitigating HIV transmission risk by transfusion may vary internationally. We compared HIV prevalence and incidence in blood donors across different jurisdictions in relation to those rates in the general population and differences in deferral practices. MATERIALS AND METHODS: Data from 2007 to 2016 were collected in Australia, Brazil (São Paulo), Canada, England, France, Italy, Ireland, Japan, the Netherlands, New Zealand, Norway, Spain (Basque Country), USA (Vitalant) and Wales. For each country/region, the number of HIV antibody-positive donations and nucleic acid testing (NAT)-only-positive donations was broken down according to first-time or repeat donor status, along with the relevant denominators. RESULTS: There is a modest correlation between HIV prevalence among first-time donors and HIV prevalence in the general population. However, rates of HIV-positive donations in repeat donors, a proxy for incidence, do not correlate with incidence rates in the general population. Rates in donors from Italy and Basque Country, where deferral criteria for men having sex with men are less stringent, are higher compared with most other jurisdictions. Rates of NAT-only-positive donations are extremely low and do not differ significantly after adjustment for multiple comparisons. CONCLUSION: Donor HIV rates are only weakly associated with those observed in the general population. Countries with less stringent deferral criteria have higher HIV rates in their donor population, but the rates remain very low.

Does time of CCI measurement affect the evaluation of platelet transfusion effectiveness?

The measurement of corrected count increment at 1-h post-transfusion (CCI-1 h) of platelet concentrate (PC) transfusion is recommended, but in the revised Japanese Guideline (2017) it was changed to "after 10-min to 1-h", following the revision of the guidelines from Western countries. Here, we aimed to investigate on the feasibility to apply the CCI measured at 10-min or 30-min post-transfusion as the surrogate of CCI-1 h. Peripheral blood was collected at 10-min, 30-min and 1-h post-transfusion of PC and the effectiveness of the transfusion was analyzed based on the CCI. In the period from December 2017 to February 2020, 8 patients, who received multiple PC transfusion (total 208) at our institution, were analyzed. We performed the univariate analyses to examine the relationship between CCI value and the categorical variables, p-value <0.1 was obtained for gender (p = 2.91 × 10-19), fever after transfusion (p = 0.0163). The qualitative variables, namely measurement time (p = 0.0553), also showed p-value <0.1. Using these factors as covariates in the mixed effect model, we found that the measurement time (p = 0.0007) had a significant effect on the CCI value when looking at fixed effects. Although there is a tendency for decreased CCI values with time progression, the slope of the change in the mixed model was -0.00307, indicating that the CCI difference among the 3 measurements was small. Here we provide evidence that CCI measured at 10-min and 30-min post-transfusion give results comparable to those measured at 1-h post-transfusion, under the Japanese practice of platelet transfusion, which relies on 100 % single-donor apheresis PC, and ABO-identical whenever possible.

Novel hybrid genes and a splice site mutation encoding the Sta antigen among Japanese blood donors.

BACKGROUND: The low-incidence antigen Sta of the MNS system is usually associated with the GP(B-A) hybrid molecule, which carries the 'N' antigen at the N terminus. The GP(A-A) molecule with trypsin-resistant M antigen has been found in a few St(a+) individuals. MATERIALS AND METHODS: Among Japanese blood donors, we screened 24 292 individuals for the presence of St(a+) with trypsin-resistant 'N' antigen and 193 009 individuals for the presence of St(a+) with trypsin-resistant M antigen. The breakpoints responsible for the Sta antigen were analysed by sequencing the genomic DNAs. RESULTS: A total of 1001 (4·1%) individuals were identified as St(a+) with trypsin-resistant 'N' antigen. Out of 1001 individuals, 115 were selected randomly for sequencing. Two novel GYP*Sch (GYP*401) variants with new intron 3 breakpoints of GYPA were detected in three cases. Twenty-five (0·013%) individuals were identified as St(a+) with trypsin-resistant M antigen. Five individuals had the GYP(A-ψB-A) hybrid allele; two of these five individuals were GYP*Zan (GYP*101.01), and the remaining three had a novel GYP(A-ψB-A) allele with the first breakpoint in GYPA exon A3 between c.178 and c.203. Nine individuals had a novel GYP(A-E-A) allele with GYPE exon E2 and pseudoexon E3 instead of GYPA exon A2 and A3. The 11 remaining individuals had a novel GYP(A-A) allele with a 9-bp deletion that included the donor splice site of intron 3 of GYPA. CONCLUSION: Our finding on diversity of glycophorin genes responsible for Sta antigen provides evidence for further complexity in the MNS system.

A novel c.166A>T (p.Thr56Ser) mutation in GYPB*S accounting for unusual S antigen expression.

We found an individual with weakened S antigen expression on red blood cells (RBCs) during routine blood grouping. The proband was typed S+s+ by polyclonal antibodies, but the RBCs demonstrated different reactivity with three monoclonal anti-S. The proband did not have alloanti-S. Cloning and Sanger sequencing revealed that the proband had a c.166A>T (p.Thr56Ser) mutation in exon 4 of GYPB*S. When antibody screening of 60 455 blood donors was performed using the proband RBCs, no antibodies were detected. GYPB*S with c.166T should encode an unusual S antigen but the creation of a novel antigen remains to be investigated.

Marked thrombocytopenia in a neonate is associated with anti-HPA-5b, anti-HLA-A31, and anti-HLA-B55 antibodies.

Maternal antibodies against human platelet antigen (HPA) and/or human leukocyte antigen (HLA) cause fetal and neonatal alloimmune thrombocytopenia (FNAIT) in 0.09-0.15% of live births. Severe cases account for 5-31% and the frequency of multiple kinds of alloantibodies is 6.9-9% of FNAIT. We present a case of severe FNAIT associated with anti-HPA-5b, anti-HLA-A31, and anti-HLA-B55 antibodies, successfully treated with immunoglobulin and platelet transfusion. The anti-HLA-B55 antibody was detected in the newborn's serum, but disappeared on the 20th day, which was followed by an increase of the platelet count. These findings suggested the potential involvement of an anti-HLA antibody in the pathogenesis of FNAIT.

Multiple HLA-matched platelet transfusions for a single patient with broad anti-HLA antibodies: a case report.

The efficacy of 30 platelet concentrate (PC) products transfused to a patient with myelodysplastic syndrome (MDS) was evaluated by calculating the 1-hour post-transfusion corrected count increment (1h-CCI). Of the 30 transfusions, all HLA-A/B-matched, the cross-match (CM) test was negative in 23 (CM(-)-PC) and weakly positive (CM(+)-PC) in 2, and the CM test was not conducted in 5 (non-CM-PC). The effective rate was higher with CM(-)-PC compared to non-CM-PC (82.6% vs 60%), but statistical significance was not achieved, which suggested that the CM test of PC may still be a not satisfactorily effective predictor of PC refractoriness. Studies are ongoing in Japan to confirm on the importance of CM test of PC.

Safety and efficacy of preoperative autologous blood donation for high-risk pregnant women: experience of a large university hospital in Japan.

AIM: Preoperative autologous blood donation (PAD) has the advantages over allogeneic blood transfusion of theoretically no risk of viral infection and alloimmunization. However, there are some concerns regarding PAD in pregnant women, as they sometimes become anemic and adverse effects such as low blood pressure could be harmful to fetuses. In our hospital, the PAD program was implemented in 2006 and has been used in pregnant women at high risk of massive hemorrhage. In this study, the safety of PAD in pregnant women and its efficacy for avoiding allogeneic blood transfusion were investigated. METHODS: The hospital records of pregnant women who delivered at our hospital from January 2009 to June 2012 were reviewed and those who were enrolled in the PAD program for predicted massive hemorrhage were analyzed. RESULTS: Among the total of 3095 deliveries, 69 cases enrolled in the PAD program were analyzed. Blood donation was performed 189 times for the 69 cases. The median donated blood volume was 1200 mL (range, 400-2000). The mean blood loss during delivery was 1976 ± 1654 mL. Autologous blood was transfused in 64 cases. Allogeneic blood transfusion was required in five cases of massive blood loss exceeding 5000 mL. In the other 64 cases, no additional allogeneic blood transfusion was required. No adverse events were observed in either the pregnant women or fetuses. CONCLUSION: For pregnant women at a high risk of massive hemorrhage, our PAD program was safe and effective for avoiding allogeneic blood transfusion.

Human umbilical vein endothelial cell vaccine therapy in patients with recurrent glioblastoma.

We aimed to assess the clinical efficacy of glutaraldehyde-fixed human umbilical vein endothelial cell (HUVEC) vaccine for the treatment of patients with recurrent glioblastoma. Patients of a HUVEC vaccine group received intradermal injections of 5 × 10(7) HUVEC weekly during the first month, and every 2 weeks from the second month, until progression of the disease was observed. Salvage treatment consisted of multimodal chemotherapy, radiation, including gamma-knife therapy, and/or repeated surgery, when feasible. Hazard ratios for death were calculated using a Cox model. A total of 17 patients with recurrent glioblastoma were enrolled in this study. All the patients received the initial treatment consisting of maximal safe surgical resection, followed by radiotherapy of 50-80 Gy or more, with concomitant and adjuvant chemotherapy consisting of temozolomide or nimustine (ACNU). A total of 352 vaccinations were performed for the patients of the HUVEC vaccine group (median number of vaccination = 11 doses; range 3-122 doses). The median progression-free survival and overall survival were 5.5 and 11.4 months, respectively. The median overall survival from the diagnosis was 24.3 months. The HUVEC vaccine therapy significantly prolonged the tumor doubling time and contributed to reducing the tumor growth rate. Hematological adverse reactions due to chemotherapy were recognized: one patient experienced grade III leukocytopenia and one showed grade II lymphocytopenia. Associated with the HUVEC vaccine therapy, a delayed-type hypersensitivity-like skin reaction developed at the injection site. The HUVEC vaccine therapy effectively controlled disease progression, without evident adverse effects, except for a delayed-type hypersensitivity-like skin reaction at the injection site.

The current status of autologous blood transfusion in Japan--the importance of pre-deposit autologous blood donation program and the needs to achieve patient blood management.

BACKGROUND: Autologous blood transfusion (ABT) is currently considered the safest transfusion, since the risks of allogeneic immunological reaction and viral transmission are theoretically null. Although its use has declined in Western countries in the recent decade, it has been progressively expanded in Japan. With the widening of the concept of patient blood management (PBM), which aims to prevent the harmful adverse effects of the exposure to allogeneic blood, the importance of the ABT has once again gained interest. STUDY DESIGN AND METHODS: Here, we retrospectively analyzed the cases pre-depositing autologous blood for an elective surgery in the period of January 2000 to December 2010 in our hospital, where a pre-deposit autologous blood donation (PAD) program has been established in 2006, in an attempt to analyze the improvements achieved, and the problems remaining to achieve patient blood management. RESULTS: The PAD program contributed for the further improvement of ABT, and the number of participating patients increased, especially in the period 2002-2003, when the idea of PAD program implementation came out. By simple extrapolation of the ABT data to allogeneic blood, ABT was found to be superior in terms of cost-effectiveness. However, problems such as the high wastage rate, and the inappropriate transfusion triggers remain to be solved. CONCLUSION: ABT plays the central role in PBM, but to achieve the real PBM, there is need to indicate ABT appropriately, according to the individual needs, and use it adequately, without discarding. Our present data reflect the present status of the ABT performance in Japan, and will serve as the basis for the development of strategies to achieve safe and appropriate performance of ABT, and consequently, achieve PBM.

Successful allogeneic hematopoietic stem cell transplantation in a patient with type I CD36 deficiency: a case study and literature review.

BACKGROUND: CD36-deficient individuals may produce anti-CD36 antibodies through antigenic exposure to CD36, in situations including blood transfusions. Therefore, allogeneic hematopoietic stem cell transplantation (HSCT) from CD36-positive donors to CD36-negative patients remains a challenge. CASE REPORT: A 64-year-old man with acute myeloid leukemia became refractory to platelet transfusions during chemotherapy. Anti-CD36 antibodies without anti-HLA antibodies were detected in serum, and the absence of CD36 expression on platelets and monocytes confirmed type I CD36 deficiency. The patient achieved complete remission, and received maintenance therapy with CD36-negative platelet transfusions. However, he relapsed soon afterward, and thus underwent peripheral blood stem cell transplantation (PBSCT) from a CD36-positive unrelated donor. The anti-CD36 antibody titer had decreased before the transplant, and the PBSCT-course was uneventful. The patient has been well without any complications associated with CD36 status mismatch. DISCUSSION: The few reports of allogeneic HSCT in patients with CD36 deficiency have suggested that anti-CD36 antibodies could be involved in several post-transplant complications, such as delayed platelet recovery, transfusion refractoriness, and transfusion-related acute lung injury. Our present case confirmed that stem cell transplantation from CD36-positive donors to negative patients is feasible, when it includes careful prior assessment of anti-CD36 antibody titers and interventions to attenuate them.