Effect of HLA-A, -B functional epitope mismatch on platelet transfusions in patients with hematological diseases / 中国输血杂志

【Objective】 To investigate the impact of human leukocyte antigen (HLA) functional epitope mismatch (EM) on the efficacy of platelet transfusion in patients with hematological diseases. 【Methods】 HLA genotyping was performed on platelet donors and patients with hematological diseases who applied for platelet serological cross-matching and HLA antigen matching from June 2021 to June 2023 by PCR-SBT method. HLA platelet matching was based on the principle of CREG to select donors for patients. HLA Matchmaker 4.0 software was used to analyze donor-recipient HLA EM information. The expression level and gene distribution of related HLA functional epitope (Eplet) were searched from the international HLA Epitope registry website (www.Epregistry.com.br). Retrospective analysis was conducted on clinical platelet transfusion data to evaluate the impact of HLA EM on platelet transfusion effectiveness. 【Results】 Platelet transfusion efficacy showed no correlation with gender and age, but it was associated with platelet matching strategy. When the total number of HLA EMs was less than 20, a lower total number of donor-recipient HLA EMs resulted in higher platelet transfusion efficiency (χ2=19.311, P=0.001) and higher average value of 24 h corrected count increment (CCI)(F=7.737, P<0.001). The total number of donor-recipient HLA EMs had negative correlation with actual 24 h CCI (Rho=-0.322, P<0.001). Further statistical analysis revealed that 17 Eplets were related to the effectiveness of platelet transfusion. The locus distribution of 17 Eplets might be unique to HLA-A (17.6%) or -B (64.7%) or shared between HLA-A and -B (17.6%), and its expression may be high (58.8%) or intermediate (41.2%). 【Conclusion】 The total number of donor-recipient HLA EMs is a crucial factor influencing platelet transfusion effectiveness, and several HLA Eplets associated with this effectiveness have been identified.

Clinical characteristics and transfusion strategies of delayed serological transfusion reactions caused by platelet transfusion in tumor patients / 中国输血杂志

【Objective】 To analyze the clinical manifestations of delayed serological transfusion reactions (DSTR) after platelet transfusion in tumor patients, and to explore the transfusion strategy. 【Methods】 Clinical data and laboratory test results of patients with positive antibody screening were analyzed after platelet transfusion in our hospital from January 1, 2015 to June 30, 2023, and the incidence rate, clinical characteristics and transfusion strategy of patients with DSTR were analyzed. 【Results】 A total of 2 553 patients with 6 057 platelet transfusions were reviewed. Eight patients developed DSTR and received a total of 21 therapeutic amounts of platelets, and 5 patients were subsequently transfused with red blood cells. Rh system antibodies were detected in 7 cases (4 anti-E, 1 anti-c/E, 1 anti-C and 1 anti-c) and Kell system antibodies in 1 case. 【Conclusion】 Tumor patients may also develop DSTR after platelet transfusion. It is necessary to pay close attention to the antibody situation and perform matched transfusion when transfusing blood again.

Distribution of platelet antibodies and their specificity in Zhongshan area / 中国输血杂志

【Objective】 To investigate the frequency of platelet antibodies in voluntary blood donors and patients in Zhongshan, Guangdong Province, and to study the specificity and cross-matching of platelet antibodies. 【Methods】 Platelet antibodies of blood donors and patients were screened by solid-phase immunoadsorption (SPIA), rechecked by flow cytometry (FCM), and antibody specificity was identified by PakPlus enzyme immunoassay, and platelet cross-matching was simulated by SPIA. 【Results】 A total of 1 049 blood donor samples and 598 patient samples were tested, with 6 (0.57%) and 49 (8.19%) samples positive for SPIA,respectively(P<0.05); In SPIA positive samples, the positive concordance rate of FCM in blood donors and patients was 100% vs 95%, and that of enzyme immunoassay was 100% vs 88%. Among the initial screening positive samples of blood donors, 5 were anti-HLA Ⅰ antibodies, accounting for 83%, and 1 was anti CD36 antibody, accounting for 17%, with an incidence rate of 0.10%. Among the 14 samples of enzyme immunoassay positive patients, 2 were anti-GP Ⅱb/Ⅲa, 1 was anti-GP Ⅱa/Ⅱa, 8 were anti HLA Ⅰ, and 3 were mixed antibodies (HLA Ⅰ, GP Ⅱb/Ⅲa, GP Ⅰa/Ⅱa). According to the types of antibodies, HLA Ⅰ antibodies were the most common, accounting for 65% (11/17), followed by HPA related anti GP, accounting for 35% (6/17). The majority of patients had a platelet antibody positive typing rate below 30%, accounting for 71.4% (10/14). 【Conclusions】 The positive rate of platelet antibody of patients in Zhongshan area is significantly higher than that of voluntary blood donors, and most of them are anti-HLA Ⅰ and anti-GP, and the incidence of anti-CD36 is extremely low. Therefore, it is necessary to establish a known platelet antigen donor bank, and at the same time, carry out platelet antibody testing and matching of patients, which is helpful to solve the issue of platelet transfusion refractoriness.

Platelet transfusion in patients with liver cirrhosis crosstalk with neutrophil: Prospective study

ABSTRACT Introduction: Immune dysfunction and thrombocytopenia are common features in liver cirrhosis. Platelet transfusion is the most widely used therapeutic approach for thrombocytopenia when indicated. The transfused platelets are prone to lesions during their storage that empower their interaction with the recipient leucocyte. These interactions modulate the host immune response. The impact of platelet transfusion on the immune system in cirrhotic patients is little understood. Therefore, this study aims to investigate the impact of platelet transfusion on neutrophil function in cirrhotic patients. Methods: This prospective cohort study was implemented on 30 cirrhotic patients receiving platelet transfusion and 30 healthy individuals as a control group. EDTA blood samples were collected from cirrhotic patients before and after an elective platelet transfusion. Flowcytometric analysis of neutrophil functions (CD11b expression and PCN formation) was performed. Results: There was a significant increase in expression of CD11b on neutrophils and Frequency of platelet-complexed neutrophils (PCN) in patients with cirrhosis compared with controls. Platelet transfusion increased level of CD11b and the frequency of PCN even more. There was a significant positive correlation between change in PCN Frequency pefore and after transfusion and the change in expression of CDllb among cirrhotic patients. Conclusions: Elective platelet transfusion appears to increase level of PCN in cirrhotic patients, moreover, exacerbate the expression of activation marker CDllb on both neutrophils and PCN. More research and studies are needed to corroborate our preliminary findings.

Detection of alloimmunization in Glanzmann Thrombasthenia and Bernard-Soulier Syndrome: Data from a Brazilian Center

ABSTRACT Introduction: The Glanzmann Thrombasthenia (GT) and Bernard-Soulier Syndrome (BSS) are rare hereditary disorders of platelet function. Their treatment often requires platelet transfusion, which can lead to the development of alloantibodies. Objective: In this study, we aim to develop a strategy for alloantibody detection and to describe the frequency of alloimmunization in a patient population from a single center in southeastern Brazil. Methods: Samples from patients with GT or BSS were tested using the Platelet Immunofluorescence Test (PIFT). If a positive result was obtained, a confirmatory step using the Monoclonal Antibody Immobilization of Platelet Antigens (MAIPA) and Luminex bead-based platelet assay (PAKLx) was executed. Main results: Among 11 patients with GT, we detected the presence of alloantibodies in 5 using PIFT, with confirmation through MAIPA and PAKLx in 2 (1 anti-HLA and 1 anti-HPA), resulting in a frequency of 18.1%. Among 4 patients with BSS, PIFT was positive in 3, with confirmation by MAIPA and PAKLx in 1 (anti-HLA), showing a frequency of 25%. The two patients with anti-HLA antibodies exhibited a panel reactive antibody (PRA-HLA) testing greater than 97%. Conclusion: Our study highlights the importance of identifying platelet alloimmunization in this patient population. The proposed algorithm for platelet alloantibodies detection allows resource optimization.

Platelet Transfusion Strategies for MASPAT-Matched Platelet Transfusion Failed Patient with Allogeneic Hematopoietic Stem Cell Transplantation / 中国实验血液学杂志

OBJECTIVE@#To investigate the causes of ineffectiveness of platelet transfusion with monoclonal antibody solid phase platelet antibody test (MASPAT) matching in patients with allogeneic hematopoietic stem cell transplantation and explore the strategies of platelet transfusion.@*METHODS@#A case of donor-specific HLA antibodies (DSA) induced by transfusion which ultimately resulted in transplantation failure and ineffective platelet transfusion with MASPAT matching was selected, and the causes of ineffective platelet transfusion and platelet transfusion strategy were retrospectively analyzed.@*RESULTS@#The 32-year-old female patient was diagnosed as acute myeloid leukemia (high risk) in another hospital with the main symptoms of fever and leukopenia, who should be admitted for hematopoietic stem cell transplantation after remission by chemotherapy. In the course of chemotherapy, DSA was generated due to platelet transfusion, and had HLA gene loci incompatible with the donor of the first transplant, leading to the failure of the first transplant. The patient received platelet transfusion for several times before and after transplantation, and the results showed that the effective rate of MASPAT matched platelet transfusion was only 35.3%. Further analysis showed that the reason for the ineffective platelet transfusion was due to the missed detection of antibodies by MASPAT method. During the second hematopoietic stem cell transplantation, the DSA-negative donor was selected, and the matching platelets but ineffective transfusion during the primary transplantation were avoided. Finally, the patient was successfully transplanted and discharged from hospital.@*CONCLUSIONS@#DSA can cause graft failure or render the graft ineffective. For the platelet transfusion of patients with DSA, the platelet transfusion strategy with matching type only using MASPAT method will miss the detection of antibodies, resulting in invalid platelet transfusion.

Factors affecting the efficacy of platelet transfusion and specificity of HLA-Ⅰ antibodies in tumor patients / 中国输血杂志

【Objective】 To analyze the factors affecting the efficacy of platelet transfusion and the specificity of HLA-Ⅰ antibodies in tumor patients. 【Methods】 Tumer patients applied for platelet transfusion from November 2019 to July 2021 in Sichuan Cancer Hospital province were screened for platelet antibodies. The transfusion efficacy was evaluated and its influencing factors were analyzed, Antibody positive patients were detected for HLA-Ⅰ antibodies. 【Results】 The positive rates of platelet antibody and HLA-Ⅰ antibody, as well as the platelet transfusion refractoriness rate were 35.2%(50/142), 32.4%(46/142) and 16.9%(24/142), respectively. The platelet refractoriness rate of platelet antibody positive patients was higher than that of platelet antibody negative patients [30.0%(15/50) vs 9.8%(9/92)] (χ2=9.428, P<0.05). Multivariate logistic results showed that gender (χ2=12.608, P<0.001, OR=3.800, 95%CI: 1.819-7.940) was an independent risk factor for platelet antibody production, and platelet antibody(χ2=8.648, P<0.05, OR=3.952, 95%CI: 1.581~9.878) was the independent risk factor for transfusion efficacy. The detection rates of strong positive, positive and weak positive HLA-I antibodies were 69.6% (32/46), 80.4% (37/46) and 97.8% (45/46), respectively. The antibodies with high detection rate were anti-B*15∶12, anti-B*57∶03, anti-B*57∶01, anti-B*13∶02, anti-B*49∶01, anti-B*50∶01, anti-A*25∶01, anti-B*15∶01, anti-B*15∶02 and anti-B*44∶02. There were 19 kinds of HLA-Ⅰ antibodies with MFI≥10 000, including anti-A*02∶01, anti-A*02∶03 and anti-A*02∶06. The CCI values were lower in HLA-Ⅰ antibody positive patients(n=46) than in HLA-I antibody negative patients(n=96) by Wilcoxon test (P<0.05). 【Conclusion】 Among tumor patients who received platelet transfusion, gender(female) was the risk factor for platelet antibody production. Platelet antibody positive patients were prone to platelet transfusion refractoriness. HLA-Ⅰ antibodies were the main platelet antibodies, suggesting that HLA-Ⅰ gene matching platelets could improve the efficacy of platelet transfusion.

Efficacy of low dose apheresis platelet prophylactic infusion in hematological diseases: a retrospective study / 中国输血杂志

【Objective】 To retrospectively analyze the efficacy of low dose apheresis platelet prophylactic infusion and explore its feasibility. 【Methods】 A total of 392 inpatients with platelet transfusion in our hospital from November 2020 to September 2021 were selected. The conventional dose (1 therapeutic dose) of apheresis platelet transfusion was set as the control group, and the low dose (0.5 therapeutic dose) as the experimental group. Platelet count before and after infusion, platelet elevation value (△PLT) and 24 h platelet count correction increase index (CCI) were observed, and the efficacy of low-dose platelet infusion was analyzed by disease type and gender. 【Results】 The △PLT value and 24h CCI effective infusion rate in control group were higher than those in experimental group: (16±16) ×109 vs (7±10) ×109, 71.94% vs 60.46%, P<0.05. The △PLT value of the control group was about 1.2-3.5 times that of the experimental group, and the effective rate was about 1-1.4 times. In control group, the △PLT (×109) was AML (20±14) >AA (14±14) >ALL (13±12) >NHL (9±8) >MDS (7±6). In the experimental group, the △PLT (×109) was AA (11±18) >AML (8±8) >ALL (5±7) >NHL (5±7) >MDS (6±16). The 24h CCI was AML(163/188, 86.70%)>AA(23/32, 71.88%)>ALL(65/98, 66.33%)>MDS(9/17, 52.94%)>NHL(12/22, 51.55%) in the control group, and AML(133/188, 70.74%)>AA(19/32, 59.38%)>NHL(12/22, 51.55%)>ALL(47/98, 47.96%)>MDS(8/17, 47.06%) in the experimental group. The effective infusion rates of AML and ALL2 in the experimental groups were 70.74% (133/188) and 47.96% (47/98), respectively, significantly lower than 86.7% (163/188) and 66.33% (65/98) in the control group(P<0.05). No significant difference was noticed in the effective infusion rate between the experimental group and the control group for other diseases (P>0.05). 【Conclusion】 Low-dose apheresis platelet prophylactic infusion can alleviate the between supply shortage, with an effective infusion rate of 60.46% (236/392), which has certain clinical application value. Patients with AML, AA or ALL were recommended with low dose platelets, while patients with MDS and NHL were not recommended.

Study on the extensibility of platelet donor gene database in Shaanxi / 中国输血杂志

【Objective】 To analyze the commonality and characteristics between voluntary blood donors and hematopoietic stem cell donors in this region, and explore the potential for integration and development between China Marrow Donors Program (CMDP) and voluntary blood donors, especially platelet donor databases, so as to improve recruitment success rate and inventory rate. 【Methods】 The database modeling and comparison methods were used to screen and stratify the matching and integration degree between the voluntary blood donors in recent 10 years and the marrow donors in the Shaanxi Branch of CMDP. The frequencies of HLA-A,-B alleles, HPA alleles and haplotypes were calculated with Arlequin 3. 5. 2. 2 software, and the matching probability of different platelet donor reserve pools was conducted according to the phenotypic frequencies. 【Results】 Among the voluntary donors with known HLA genotypes in this region, according to their blood donation behavior,the active blood donors excavated were divided into the first, second, third and fourth echelons of platelet donor reserve pools, with 696, 2 752, 9 092 and 12 028 donors, respectively. The first echelon had the highest proportion of 10-50 times of platelet donations and 10-20 times of whole blood donations, with 13.65% and 26.01%, respectively. The second echelon had 10-20 times of whole blood donations and 10-50 times of platelet donations, accounted for 15.04% and 1.38%, respectively, which were significantly different from other echelons' blood donation characteristics (P<0.05). With a database size of the existing platelet donor bank adding the first and second echelons (n=4 955), there was a 69.02% probability of matching at least one donor with matching HLA-A-B phenotype. When considering the matching ABO and HPA phenotypes, the probability of finding at least one donor with fully matching HLA, HPA and ABO isotype (type B as an example) was 48. 73%. 【Conclusion】 The three groups of whole blood donation, apheresis platelet donation and marrow donation in Xi'an area have a large cross-distribution. Compared with expanding the storage capacity from scratch, the active blood donors in CMDP database are the largest back-up force of platelet donors. While expanding the effective storage capacity, it can minimize the cost of building platelet donor bank and the demand for resources.

Research status of additives related to platelet preservation / 中国输血杂志

Platelets play an important role in hemostasis, inflammation, tumor metastasis, wound healing and defense response, but its routine storage requires a specific temperature and the storage time is generally limited to 5 ~7 d, at the same time, platelet storage damage and bacterial breeding will limit its storage time. In addition, routine transfusion can cause serious adverse reactions such as non-hemolytic fever, allergies, circulatory overload, and transfusion-related acute lung injury. These limit the clinical application of platelet products. However, additives associated with platelet preservation can reduce the likelihood of their occurrence. Therefore, this article reviews the research status of additives related to platelet preservation in recent years, as well as improving platelet storage damage and improving platelet preservation characteristics.

Matching strategy for patients with platelet transfusion refractoriness caused by compound antibodies against HLA and CD36 / 中国输血杂志

【Objective】 To search compatible and suitable platelets for platelet transfusion refractoriness (PTR) patient caused by compound antibodies against HLA and CD36. 【Methods】 ELISA method was used to detect the antibody against platelet antigens and the specificity of HLA-I antibody in PTR patients. The specificity of HLA-I antibody and corresponding epitopes of patients were analyzed using MATCH IT! and HLA Matchmaker software. The HLA genotype of both donor and patient was obtained by HLA-SSO method. Compatible or suitable donor platelets for PTR patients were searched through cross-reactive group (CREG) of HLA-I and HLA epitope-matched approach (Eplet). The matching degree was identified using monoclonal antibody-specific immobilization of platelet antigens (MAIPA) and the platelet suspension immunofluores-cence test (PIFT). Finally, the transfusion effect was evaluated according to the corrected count increment (CCI). 【Results】 Compound antibodies against both CD36 and HLA-I antigens were detected in two PTR patients, and their phenotype of CD36 was conformed to be type I deficient. Through LSA testing, high-frequency of HLA -I antibodies was found in these two patients, and the panel reactive antibody in patients 1 and 2 was 56% (54/96) and 53% (51/96), respectively. According to HLA-CREG and Eplet matching strategies, one donor of grade C-matching with patient 1 and one donor of grade D-matching with patient 2 were screened from the CD36 deficiency donor bank, respectively. And the selected donors avoided the antigen of HLA-I antibody epitope. These results of MAIPA and PIFT also confirmed that no immune response was detected between the patient and the donor. And a CCI of >4.5 within 24 hour of transfusion of compatible platelets was obtained in patient 2. 【Conclusion】 For PTR patients caused by HLA and CD36 compound antibodies, a combination strategy including serological cross-matching, HLA-CREG and Eplet approach should be used to select the CD36 deficient donor platelets which evaded the antigen corresponding to HLA-I antibodies and had the compatible HLA epitopes.

Establishment and evaluation of predictive models of platelet transfusion effect in multi-center tumor patients / 中国输血杂志

【Objective】 To study the platelet transfusion predictive models in tumor patients and evaluate its application effect. 【Methods】 A retrospective study was conducted on 944 tumor patients, including 533 males and 411 females who received platelet transfusion in the Affiliated Hospital of Traditional Chinese Medicine of Xinjiang Medical University, the Affiliated Cancer Hospital of Xinjiang Medical University and Kailuan General Hospital from August 2022 to January 2023. Multivariate Logistic regression analysis was used to establish the platelet transfusion predictive models, and Medcalc15.8 software was used to draw the receiver operating curve (ROC) to evaluate the application effect of the prediction model. The actual application effect of models was verified through 162 female clinical cases and 172 male clinical cases. 【Results】 The incidence of platelet transfusion refractoriness in tumor patients was 28.9% (273/944), with 33.2% (177/533) in males, significantly higher than that in females [23.4% (96/411)] (P<0.05). Platelet transfusion predictive models: Y1 (female) =-8.546+ (0.581×number of pregnancies) + (0.964×number of inpatient transfusion bags) + number of previous platelet transfusion bags (5-9 bags: 1.259, ≥20 bags: 1.959) + clinical diagnosis (lymphoma: 2.562, leukemia: 3.214); Y2 (male) =-7.600+ (1.150×inpatient transfusion bags) + previous platelet transfusion bags (10-19 bags: 1.015, ≥20 bags: 0.979) + clinical diagnosis (lymphoma: 1.81, leukemia: 3.208, liver cancer: 1.714). Application effect evaluation: The AUC (area under the curve), cut-off point, corresponding sensitivity and specificity of female and male platelet transfusion effect prediction models were 0.868, -0.354, 68.75%, 89.84% and 0.854, -0.942, 81.36%, 77.53%, respectively. Actual application results showed that the sensitivity, specificity, and accuracy of female and male model were 89.47%, 92.74%, 91.98% and 83.72%, 91.47%, 89.53%, respectively. 【Conclusion】 There is high incidence of platelet transfusion refractoriness in tumor patients, and the predictive model has good prediction effect on platelet transfusion refractoriness in tumor patients, which can provide reliable basis for accurate platelet transfusion in tumor patients.

Effect of AB platelet secondary compatible transfusion on the efficacy of matched platelet transfusion / 中国输血杂志

【Objective】 To retrospectively analyze the effect of AB platelet secondary compatible transfusion on the efficacy of matched platelet transfusion. 【Methods】 A total of 2 276 cases of platelet transfusion in our hospital were selected from November 2020 to September 2021, including 2 068 ABO matched platelet transfusions and 206 AB platelet secondary compatible transfusions. 117 cases were selected for the first occasion of AB platelet secondary compatible transfusion. The controls were matched transfusion receipts before given AB platelet secondary compatible transfusion, and the experimental group was given matched transfusion after AB platelet secondary compatible transfusion (take the first, second and third transfusion as group 1, 2 and 3, respectively). The platelet count(Plt), platelet elevation (△Plt) and 24 h Plt correction increase index (CCI) of patients before and after platelet transfusion were used as observation indexes to analyze the effect of AB type mis-matched platelet transfusion on the efficacy of matched platelet preventive transfusion by gender, blood type and disease type. 【Results】 Among the 2 276 platelet transfusions, and the △Plt of matched platelet transfusions was significantly higher than that of AB type secondary compatible transfusions, with the mean values at (14±15)×109/L and (11±14)×109/L(P<0.05). The △Plt of female patients was higher than that of male patients (15±16)×109/L vs (13±14)×109/L(P < 0.05). The △Plt values of MDS, NHL and MM were (9±14) ×109/L, (10±12) ×109/L and (8±11) ×109/L, respectively, which were significantly lower than the average value (P < 0.05). For 117 cases of AB platelet secondary compatible transfusion: the Δ Plt was significantly lower than that of the control group and the experimental group, respectively at (9±12) ×109/L, (13±13) ×109/L and (13±12) ×109/L(P<0.05). The effective rate of 24 h CCI was 52.14%, significantly lower than the control group and experimental group (71.59% vs 71.83%), P<0.05; no significant difference was noticed in △ Plt value and 24 h CCI between the experimental group and the control group(P>0.05). The △Plt of the experimental group 3 was significantly lower compared with the experimental group 1, (10±13) ×109/L vs (14±12) ×109/L, P<0.05, and the effective rate decreased from 73.12%(68/93)to 58.70%(27/46), P>0.05. No significant difference in △Plt and the number of effective 24 h CCI cases was found between the experimental group and the control group in terms of gender, blood type and disease type (P>0.05). 【Conclusion】 The △Plt and the effective rate of AB platelet secondary compatible transfusion were lower than those of matched platelet transfusions, and has no significant effect on short term(less than 10 days) matched platelet transfusion.

Transfusion effect of 0.5-dose of apheresis platelet in pediatric patients / 中国输血杂志

【Objective】 To investigate the transfusion effect of 0.5-dose of apheresis platelet in pediatric patients. 【Methods】 A total of 195 children who underwent 0.5-dose platelet transfusion from August 2021 to June 2022 were enrolled, and the platelet count within 24 hours before and after platelet transfusion were recorded. They were grouped by gender, disease type, blood product transfusion history, platelet antibody results, platelet storage time and weight to analyze the effect of platelet transfusion. 【Results】 Among 195 cases, 77.4% (151/195) were effective and 22.6% (44/195) were ineffective after 0.5-dose of platelet transfusion. Platelet transfusion more than three times has significant impact on the effectiveness of platelet transfusion, with platelet transfusion efficiency decreased from 80.8% to 65.9% (P<0.05), and CCI decreased from 11.56±8.94 to 8.52±8.42 (P<0.05). The transfusion effect of the HLA and HPA antibodies positive group was significantly lower than the negative group, with CCI decreased from 11.39±8.87 to 7.82±8.59 (P=0.05). Linear regression analysis showed that the effect of platelet transfusion decreased with the increasing of platelet storage time (P<0.05), and the effect of platelet transfusion decreased in children weighing less than 20 kg compared with those weighing more than 20 kg, with the effective rate decreased from 84.1% to 63.5% (P<0.05). Different gender, disease type and the number of red blood cell transfusions had no significant effect on platelet transfusion. 【Conclusion】 The 0.5-dose platelet transfusion has good therapeutic effect in children below 20 kg. The results of HLA and HPA antibodies and the number of platelet transfusions greatly influence the effect of platelet transfusion in children, and the transfusion effect decreases with the increase of platelet storage time.

Efficacy of apheresis platelet transfusion in 310 patients with haematological diseases / 中国输血杂志

【Objective】 To observe the effect of platelet transfusion in inpatients with haematological diseases, analyze the possible causes of platelet transfusion refractoriness (PTR), in order to further improve the efficacy of platelet transfusion. 【Methods】 A total of 310 patients with blood disease in our hospital from August 2020 to November 2021 who received platelet transfusion were retrospectively analyzed. Possible influencing factors of platelet transfusion, including gender, age, platelet preservation time, number of platelet transfusions, complication and red blood cell product transfusion were analyzed. 【Results】 Patients were divided into effective group and refractory group according to percentage platelet recovery (PPR) and corrected count increment (CCI). PTR was defined as PPR <20% or CCI <5 000 after two consecutive transfusions in 24 h or clinical bleeding symptoms or tendency not significantly controlled. Statistical differences were noticed between the two groups in terms of gender, pretransfusion white blood cell count, anemia, and whether antibiotics were used (P<0.05). The type of disease, gender, anemia and number of comorbidities were associated with PTR. The incidence of PTR was the highest in patients with myelodysplastic syndrome, and the incidence of PTR was higher in men than in women. Transfusion units of suspended red blood cells and the number of comorbidities were negatively correlated with the transfusion efficacy (P<0.05). 【Conclusion】 Possible influencing factors of platelet transfusion included the level of white blood cells before transfusion, use of antibiotics, anemia and transfusion of red blood cells, number of comorbidities, and type of disease, while no significant differences were found in age, hemolysis, hypersplenism, platelet preservation time, and number of platelet transfusions on transfusion efficacy.

The effect of platelet infusion on the repair of bone marrow hematopoietic niche damage in mice induced by (60)Co radiation and hematopoietic reconstruction after bone marrow transplantation / 中华血液学杂志

Objective: To observe the effect of platelets on hematopoietic stem cell (HSCs) implantation in mice with radiation-induced bone marrow injury and bone marrow transplantation models. Methods: ①Male C57BL/6 mice were divided into a single irradiation group and a radiation infusion group after receiving (60)Co semimyeloablative irradiation for 18-10 weeks. The irradiation infusion group received 1×10(8) platelets expressing GFP fluorescent protein. ② The allogeneic bone marrow transplantation model was established. The experimental groups included the simple transplantation group (BMT) and the transplantation infusion group (BMT+PLT). The BMT group was infused through the tail vein only 5 × 10(6) bone marrow cells, the BMT+PLT group needs to be infused with bone marrow cells at the same time 1× 10(8) platelets. ③ Test indicators included peripheral blood cell and bone marrow cell counts, flow cytometry to detect the proportion of hematopoietic stem cell (HSC) and hematopoietic progenitor cells, bone marrow cell proliferation and apoptosis, and pathological observation of vascular niche damage and repair. Results: ①On the 3rd, 7th, 14(th), and 21st days after irradiation, the bone marrow cell count of the infusion group was higher than that in the single irradiation group (P<0.05), and the peripheral blood cell count was also higher. A statistically significant difference was found between the white blood cell count on the 21st day and the platelet count on the 7th day (P<0.05). In the observation cycle, the percentage of bone marrow cell proliferation in the infusion group was higher, while the percentage of apoptosis was lower. ② The results of bone tissue immunofluorescence after irradiation showed that the continuity of hematopoietic niche with red fluorescence was better in the irradiation infusion group. ③The chimerism percentage in the BMT+PLT group was always higher than that in the BMT group after transplantation.④ The BMT+PLT group had higher bone marrow cell count and percentage of bone marrow cell proliferation on the 7th and 28th day after transplantation than that in the BMT group, and the percentage of bone marrow cell apoptosis on the 14th day was lower than that in the BMT group (P<0.05). After the 14th day, the percentage of stem progenitor cells in the bone marrow cells of mice was higher than that in the BMT group (P<0.05). ⑤The immunohistochemical results of bone marrow tissue showed that the continuity of vascular endothelium in the BMT+PLT group was better than that in the BMT group. Conclusion: Platelet transfusion can alleviate the injury of vascular niche, promotes HSC homing, and is beneficial to hematopoietic reconstruction.

Predicting donor-related factors for high platelet yield donations by classification and regression tree analysis

Introduction Collecting high-dose (HD) or double-dose (DD) apheresis platelets units from a single collection offers significant benefit by improving inventory logistics and minimizing the cost per unit produced. Platelet collection yield by apheresis is primarily influenced by donor factors, but the cell separator used also affects the collection yield. Objectives To predict the cutoff in donor factors resulting in HD and DD platelet collections between Trima/Spectra Optia and MCS+ apheresis equipment using Classification and Regression Trees (CART) analysis. Methods High platelet yield collections (target ≥ 4.5 × 1011 platelets) using MCS+, Trima Accel and Spectra Optia were included. Endpoints were ≥ 6 × 1011 platelets for DD and ≥ 4.5 to < 6 × 1011 for HD collections. The CART, a tree building technique, was used to predict the donor factors resulting in high-yield platelet collections in Trima/Spectra Optia and MCS+ equipment by R programming. Results Out of 1,102 donations, the DDs represented 60% and the HDs, 31%. The Trima/Spectra Optia predicted higher success rates when the donor platelet count was set at ≥ 205 × 103/µl and ≥ 237 × 103/µl for HD and DD collections. The MCS+ predicted better success when the donor platelet count was ≥ 286 × 103/µl for HD and ≥ 384 × 103/µl for DD collections. Increased donor weight helped counter the effects of lower donor platelet counts only for HD collections in both the equipment. Conclusions The donor platelet count and weight formed the strongest criteria for predicting high platelet yield donations. Success rates for collecting DD and HD products were higher in the Trima/Spectra Optia, as they require lower donor platelet count and body weight than the MCS+.

Analysis and prospect of platelet compatible transfusion / 中国输血杂志

Platelet compatible transfusion can effectively solve the immune mediated platelet transfusion refractoriness (PTR), save platelet resources and improve blood safety. This paper comments and prospects the compatibility modes of HLA, HPA and CD36, HLA antibody titer, antigen immunogenicity and the development of platelet compatible transfusion. The pattern of HLA compatible platelets involves the matching in the alleles, antigens and epitopes levels, respectively, as well as avoidance donor specificity antibody (DSA) method. While setting the mean fluorescence intensity (MFI) threshold of avoidance DSA needs to be explored when using the DSA prediction method. Allele specific HLA antibodies can be found in the patients with PTR. Therefore, the patients and donors should be genotyped for HLA-A, -B loci at high-resolution level in order to avoid allele specific HLA antibodies. The immunogenicity of various antigens or epitopes at HLA-A and -B loci are different. Selecting donor platelets with low antigen expression or low immunogenicity may be a way of HLA compatible platelets. As the probability and type of HPA antibody production are different in the various populations, the approaching of compatibility HPA involves allele matching and avoidance DSA. As to CD36, the compatibility mode mainly refers to avoidance DSA, which means blood donors with CD36 antigen type Ⅰdeficiency are preferentially selected, and then those with CD36 antigen type Ⅱ deficiency. In the future, more attention should be paid to the scale up of database capacity and update of the information construction. The time waiting for compatible platelets transfusion in clinical could be significantly shortened if the requiring and matching are only conducted within the inventory and candidate platelets.

Correlation between the quantitative intensity of HLA-Ⅰ gene and its antibody and the clinical transfusion effect of matching platelets / 中国输血杂志

【Objective】 To explore the influence of anti-HLA-Ⅰ with different mean fluorescence intensity (MFI) on the efficacy of HLA-A and -B gene matching platelet transfusion, so as to provide scientific data for clinical platelet gene matching transfusion strategy. 【Methods】 A total of 81 PTR patients had applied for HLA-Ⅰgene matched platelets from the platelet gene database established by our laboratory, and 28 (MFI <5 000) of them needed further avoiding of partial donor-specific antibodies and they were enrolled as the research subjects. According to the platelet MFI value of HLA-Ⅰ antibody-targeting antigen, they were divided into negative transfusion group (MFI <500) (group A) and positive transfusion groups (MFI≥500) ; the latter were further divided into group B (500≤MFI <1 000), group C (1 000≤MFI <3 000) and group D (MFI≥3 000) according to MFI value. Corrected count increment (CCI) in platelet count was used to compare the platelet transfusion effect in 4 groups. 【Results】 Among 28 platelet recipients with MFI <5 000, 19(67.86%) patients successfully received 72 effective transfusions. The first CCI (×109/L) in groups A, B, C and D were 10.27±7.46, 7.58±4.75 (P>0.05), 17.36±7.63 (P>0.05) and -0.77±2.30 (P<0.05), respectively. There was no statistical difference among group A, B and C. 【Conclusion】 The application of HLA-Ⅰ gene matching platelets in PTR patients can adjust the MFI threshold(<2 000) appropriately according to the patient′s condition without compromising the platelet transfusion effect.

Analysis of HLA-Ⅰ antibody specificity and estimation of antigen immunogenicity: 96 patients recieved genotype-matched platelet transfusions / 中国输血杂志

【Objective】 To analyze the specificity of HLA class-Ⅰ antibody in the patients received HLA-matched platelet transfusions and estimate the relative immunogenicity of HLA-Ⅰ antigens. 【Methods】 The samples from 96 patients who suffered from platelet transfusion refractorines(PTR) and applied for transfusion with genotype-matched platelet were collected. The specificity of HLA I antibody was detected by Luminex technique, and the antibody expression level was analyzed according to MFI. The mismatch rate of HLA antigen and relative immunogenicity of the population were estimated according to the allele frequency distribution of HLA-A and B loci as well as the yielding frequency of antibody. 【Results】 HLA-Ⅰ antibodies were detected in all 96 patients, with varied species of antibodies. The average positive yielding rates of antibodies corresponding to HLA-A, -B and -C magnetic bead coated antigens (97 in total) were 0.38, 0.47 and 0.28, respectively. Among the HLA-A and -B loci in the Zhejiang population, HLA-A2, A11, A24 and HLA-B60, B46, B58 were the antigens with higher frequency, and their relative immunogenicity was 0.403, 0.283, 0.342, and 0.100, 0.067, 0.178, respectively. 【Conclusion】 The specificity of HLA-Ⅰ antibodies in PTR patients is different, which confirms that the relative immunogenicity differs by HLA-A and -B antigens.