A study of blood group conversion in patients with ABO incompatible hematopoietic stem cell transplantation-A decade survey.

BACKGROUND: ABO incompatibility is not a contraindication but would affect the prognosis of allogeneic hematopoietic stem cell transplantation (allo-HSCT). The dynamic change of blood phenotype is not only related to the patient's status, but also the basis for the implementation of compatible blood transfusion. The criteria for judging a complete transformation to donor-type and the principle of blood transfusion at relapse need to be unified. We aimed to illustrate the significance of blood group monitoring after allo-HSCT. MATERIAL AND METHODS: We collected 263 patients underwent ABO incompatible allo-HSCT from January 2010 to December 2019, and monitored blood type regularly according to the frequency of the patient's return visits till complete conversion or death. Non-parametric test was used to find differences among incompatible groups. We analyzed factors potentially influence blood type conversion by Binary Logistic model. Cox regression model was used to illustrate the relationship between blood-type conversion and prognosis. RESULTS: The median days of conversion were 107, 91 and 108 in major-, minor- and bidirectional groups respectively. Blood type conversion correlated with HLA compatibility (P = 0.012, OR=2.69) and acute graft-versus-host-disease (P = 0.001, OR=0.06). Patients with incomplete blood type conversion had a higher death rate than those with complete blood type conversion(P = 0.003, OR=3.703). DISCUSSION: Blood type monitoring can help to evaluate the prognosis of transplantation and assess the risk of death. It is recommended to monitor the changes of blood group antigens and antibodies, especially within a year after transplantation, to predict the risk of adverse events (such as GVHD, recurrence, death, etc.).

Delayed two steps PRP injection strategy for the improvement of fat graft survival with superior angiogenesis.

Platelet-rich plasma (PRP) has been widely used to improve the fat retention rate in autologous fat transplantation since it possesses a good angiogenesis capability in vivo. However, due to the short half-life of growth factors released from PRP and its uneven distribution in injected fat tissue, the strategy of PRP in fat transplantation needs further improvement. Since the capillaries started to grow into fat grafts in 1 week and vascular growth peaks in the second week after transplantation, we hypothesized that delayed two-steps PRP injection into the interior of grafts, accompanied with the extent of neovascularization might theoretically promote microvessel growth inside transplanted adipose tissue. 24 nude mice were divided into three groups: Blank group (0.35 mL fat mixed with 0.15 mL saline, N = 8), Single step group (0.35 mL fat mixed with 0.15 mLPRP, N = 8), and Two steps group (0.35 mL fat (day 0) + 0.075 mL PRP (day 7) + 0.075 mL PRP (day 14), N = 8). At 6 and 14 weeks post-transplantation, grafts were dissected, weighted, and assessed for histology, angiogenesis, fat regeneration and inflammation level. The weight and volume of the fat samples revealed no statistical difference among the three groups at 6 weeks after fat transplantation. The weight and volume of the Two steps group fat samples showed significantly higher compared to that in Blank and Single step groups at 14 weeks after fat transplantation (weight: 137.25 ± 5.60 mg versus 87.5 ± 3.90 mg,106.75 ± 2.94 mg, respectively; volume: 0.13 ± 0.01 mL versus 0.08 ± 0.01 mL, 0.09 ± 0.01 mL, respectively). Histological assessments indicated that delayed two-steps PRP injection strategy helps to improve adipose tissue content and reduce the composition of fibrous connective tissue at 14 weeks after fat transplantation. At 6 weeks and 14 weeks after transplantation, CD31 immunofluorescence indicated that delayed two-steps PRP injection strategy helps to improve angiogenesis and significantly higher compared to that in Blank and Single step groups (6 weeks: 28.75 ± 4.54 versus 10.50 ± 2.06, 21.75 ± 1.85; 14 weeks: 21.75 ± 2.86 versus 9.87 ± 2.08, 11.75 ± 1.47, respectively). Preadipocyte count indicated delayed two-steps PRP injection strategy might promote fat regeneration and significantly higher compared to that in Blank and Single step groups at 14 weeks (129.75 ± 6.57 versus 13.50 ± 3.50, 17.12 ± 6.23, respectively). In this study, we demonstrated that the novel delayed two-steps PRP injection strategy remarkably enhanced the long-term fat retention rate and improved the neovascularization extent in the interior of the fat graft. Platelet-rich plasma, Delayed two-steps injection, Angiogenesis, Fat transplantation.

Faulty blood typing misled by auto anti-D in AIHA.

Pre-transfusion testing is a vital link to enhance patients' safety but may be influenced by heterotypic blood transfusion and disease. Previous history of blood transfusion most of time help us determine the blood type. On the other hand, it can also mislead technicians to a wrong conclusion. Anti-D, which is clinically important in hemolytic transfusion reaction, is either alloimmunized by transfusion, pregnancy or induced in certain diseases. Here, we reported a rare case with false blood identification interfered by heterotypic blood transfusion and auto anti-D in autoimmune hemolytic anemia (AIHA).

Evaluation of erythroblast macrophage protein related to erythroblastic islands in patients with hematopoietic stem cell transplantation.

BACKGROUND: Hematopoietic evaluation of the patients after Hematopoietic stem cell transplantation (HSCT) is very important. Erythroblast macrophage protein (Emp) is a key protein with function in normal differentiation of erythroid cells and macrophages. Emp expression correlates with erythroblastic island formation, a process widely believed to be associated with hematopoiesis in bone marrow. We aimed to investigate the hematopoietic function of bone marrow from 46 HSCT patients and 16 inpatients with severe anemia applied to the treatment of EPO by measuring Emp expression level. METHODS: Emp mRNA and protein expression levels in mononuclear cells of bone marrow and peripheral blood samples were detected by RT-PCR and Western blotting method respectively. RESULTS: While hematopoiesis occurs in bone marrow, Emp expression level was elevated and more erythroblastic islands were found , and Emp is upregulated in bone marrow in response to erythropoietin (EPO) treatment. CONCLUSIONS: Emp expression correlates with erythroblastic island formation and has an important function for bone marrow hematopoiesis. Emp could be a potential biomarker for hematopoietic evaluation of HSCT patients.

ABO chimerism determined by real-time polymerase chain reaction analysis after ABO-incompatible haematopoietic stem cell transplantation.

BACKGROUND: The dynamic alteration of ABO blood group in ABO-incompatible haematopoietic stem cell transplantation can be well defined by ABO chimerism analysis. In view of the intrinsic difference in ABO phenotypes or genotypes between donor and recipient in ABO incompatible transplantation, ABO allele-associated nucleotide polymorphic sites could theoretically be used as available informative markers for chimerism analysis. MATERIALS AND METHODS: We chose nucleotide polymorphism sites (261, 467, 802, 803 and 1,061) of common ABO alleles to use as markers from 76 randomly chosen donors and assessed the limit of linear detection of a specifically designed real-time quantitative polymerase chain reaction using SYBR Green I dye with these sites for a chimerism assay. RESULTS: We successfully established the real-time quantitative polymerase chain reaction for detecting 261, 467(mutated) and 803 sites and their limits of linear detection, which were at least 10(-3), 10(-2) and 10(-2), respectively. The limits of linear detection between heterozygous DNA and homozygous DNA with 261 or 803 sites were not significantly different. DISCUSSION: ABO chimerism can be well analysed by real-time polymerase chain reaction with ABO gene-associated nucleotide polymorphic sites. This strategy could be very beneficial for the early and accurate judgement of the crucial point of transition in order to plan a safe transfusion strategy following ABO-incompatible transplantation.

Rapid and reliable genotyping of HLA-B*27 in the Chinese Han population using a duplex real-time TaqMan PCR assay.

OBJECTIVES: To develop a duplex real-time TaqMan PCR assay for genotyping HLA-B*27 in the Chinese Han population. DESIGN AND METHODS: A standard curve was constituted to deduce amplification efficiency, dynamic range and detection limit of the duplex real-time TaqMan PCR assay, whereas PCR-SBT (PCR with sequence-based typing) was used to evaluate the accuracy of the assay. RESULTS: A linear standard curve for determining HLA-B*27 was obtained within the range of 10(1)-10(9) copies per reaction with the correlation coefficient of 0.99 and amplification efficiency of 98.30%. The detection limit was 3.09 copies per reaction. Complete concordance was found between the results obtained by the duplex real-time TaqMan PCR assay and PCR-SBT. Fifty-nine of the 178 genomic samples were HLA-B*27 positive and the other 119 were HLA-B*27 negative. CONCLUSIONS: The duplex real-time TaqMan PCR approach appears to be a reliable, sensitive, rapid and high-throughput method to genotype HLA-B*27 in the Chinese Han population.

The investigation of platelet transfusion refractory in 69 malignant patients undergoing hematopoietic stem cell transplantation.

BACKGROUND: Platelet transfusion refractoriness (PTR) is thought to be associated with HPA and HLA incompatibility but be unrelated to ABO incompatibility in practice. In this study we aim to investigate the incidence of PTR and potential risks in patients undergoing hematopoietic stem cell transplantation (HSCT). METHOD: A total of 69 HSCT patients were involved with their basic characteristics recorded. PTR was identified by 24h corrected count increment (24h-CCI) post platelet transfusion and we transformed it to the corrected platelet increment (CPI), which was compared between the PTR and non PTR groups. Age, gender, ABO incompatibility, disease and CPI were analyzed by Logistic regression analysis for PTR incidence. We searched our medical records to find possible risks of PTR with different levels of CPI. RESULTS: There was no significant difference of platelet engraftment (PE) (P=0.271) and platelet requirement (PR) (P=0.333) between patients with ABO matched and mismatched transplants. Thirteen patients experienced PTR but with a varied refractory ratio (20-95%). Logistic regression analysis showed that the CPI <10×10(9)/l (P=0.006) was dramatically related to the PTR while ABO incompatibility (P=0.319), MDS (P=0.552), PLT count pre-transplantation <50×10(9)/l (P=0.998) were of no statistical significance. There were 142U (32.7%) of platelets transfused with unsatisfactory CPIs, mainly (48.6%) within the second week since transplantation. From the investigation of medical records, infections, fever and bleeding were the most common reasons for PTR. CONCLUSIONS: PTR is a common phenomenon but more associated with non-immune causes in HSCT. The quantification of CPI may imply potential risks of PTR and help clinicians to better use platelet apheresis.

Detection of IgG anti-A/B must be essential for safe transfusion support in patients undergoing ABO incompatible allogeneic HSCT.

Recipients of ABO incompatible allogeneic HSCT present with unusual ABO groups and crossmatch problems accompanied by change of the ABO group from that of the host to the donor. We report on a patient undergoing major ABO incompatible allogeneic HSCT (donor/recipient: A/O) whose blood group was wrongly established to have completely switched to blood group A when using a routine tube method and micro gel column blood grouping card on the 68th day post transplantation. The major crossmatch test with added antiglobulin and blood group A red cells was still positive. After further investigation, an explanation was found because we could not detect IgG anti-A in the serum. At the same time, anti-A coated the patient's RBCs and could be identified using a heat elution method although the DAT was negative. We also found an obvious mixed field with the LISS-IAT gel card. Hence, routine methods of ABO grouping are unfit for ABO incompatible allogeneic HSCT patients and a micro column neutral gel card is recommended for forward typing especially to detect mixed fields and a LISS-IAT gel card or IAT tube method for detecting IgG anti-A/B in reverse typing.