Prediction of red blood cell transfusion after orthopedic surgery using an interpretable machine learning framework.

Objective: Postoperative red blood cell (RBC) transfusion is widely used during the perioperative period but is often associated with a high risk of infection and complications. However, prediction models for RBC transfusion in patients with orthopedic surgery have not yet been developed. We aimed to identify predictors and constructed prediction models for RBC transfusion after orthopedic surgery using interpretable machine learning algorithms. Methods: This retrospective cohort study reviewed a total of 59,605 patients undergoing orthopedic surgery from June 2013 to January 2019 across 7 tertiary hospitals in China. Patients were randomly split into training (80%) and test subsets (20%). The feature selection method of recursive feature elimination (RFE) was used to identify an optimal feature subset from thirty preoperative variables, and six machine learning algorithms were applied to develop prediction models. The Shapley Additive exPlanations (SHAP) value was employed to evaluate the contribution of each predictor towards the prediction of postoperative RBC transfusion. For simplicity of the clinical utility, a risk score system was further established using the top risk factors identified by machine learning models. Results: Of the 59,605 patients with orthopedic surgery, 19,921 (33.40%) underwent postoperative RBC transfusion. The CatBoost model exhibited an AUC of 0.831 (95% CI: 0.824-0.836) on the test subset, which significantly outperformed five other prediction models. The risk of RBC transfusion was associated with old age (>60 years) and low RBC count (<4.0 × 1012/L) with clear threshold effects. Extremes of BMI, low albumin, prolonged activated partial thromboplastin time, repair and plastic operations on joint structures were additional top predictors for RBC transfusion. The risk score system derived from six risk factors performed well with an AUC of 0.801 (95% CI: 0.794-0.807) on the test subset. Conclusion: By applying an interpretable machine learning framework in a large-scale multicenter retrospective cohort, we identified novel modifiable risk factors and developed prediction models with good performance for postoperative RBC transfusion in patients undergoing orthopedic surgery. Our findings may allow more precise identification of high-risk patients for optimal control of risk factors and achieve personalized RBC transfusion for orthopedic patients.

In vitro Immunomodulatory Effects of Human Umbilical Cord-Derived Mesenchymal Stem Cells on Peripheral Blood Cells from Warm Autoimmune Hemolytic Anemia Patients.

INTRODUCTION: Autoimmune hemolytic anemia is a potentially lethal disease characterized by autoimmune hemolysis. Although human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) have been reported as a promising therapy, there is limited evidence regarding warm autoimmune hemolytic anemia (wAIHA) patients. This study aimed to investigate the potential therapeutic effects of hUC-MSCs via immune regulation in wAIHA patients. METHODS: Peripheral blood mononuclear cells (PBMCs) from 10 wAIHA patients and 8 healthy controls were isolated from peripheral blood and cultured for 3 days with or without the presence of hUC-MSCs; PBMCs were co-cultured with hUC-MSCs using Transwell assays. The supernatant cytokine levels were measured after culture through AimPlex Multiple Immunoassays for Flow, including IL-2, IL-4, IL-10, IFN-γ, TNF-α, and IL-17A. The percentages of regulatory T cells, regulatory B cells, and Th1/Th2 in PBMCs were also assessed before and after culturing. RESULTS: In the wAIHA group, hUC-MSCs could upregulate the Treg and Breg proportions after culturing for 3 days, and the Treg and Breg percentages increased after co-culturing with hUC-MSCs in the wAIHA group compared with PBMC cultured alone for 3 days (8.29 ± 8.59 vs. 6.82 ± 1.32, 3.82 ± 1.87 vs. 1.75 ± 1.20, respectively). Compared with the PBMC wAIHA group, the levels of TNF-α (2.13 ± 2.07 vs. 16.20 ± 21.13 pg/mL, p = 0.019) and IL-10 (10.51 ± 18.42 vs. 37.78 ± 44.20 pg/mL, p = 0.012) were significantly elevated in the PBMC + hUC-MSCs wAIHA group. CONCLUSION: The hUC-MSCs contributed to the increasing proportion of regulatory cell populations in PBMCs of wAIHA patients, thereby potentially regulating autoimmune response; thus, hUC-MSCs may be a promising approach for wAIHA treatment.

Prevalence and intervention of preoperative anemia in Chinese adults: A retrospective cross-sectional study based on national preoperative anemia database.

BACKGROUND: Preoperative anemia is an important pillar of perioperative patient blood management. However, there was no literature comprehensively described the current situation of preoperative anemia in China. METHODS: We conducted a national retrospective cross-sectional study to assess the prevalence and intervention of preoperative anemia in Chinese adults. Data were from the National Preoperative Anemia Database based on hospital administration data from January 1, 2013 to December 31, 2018. FINDINGS: A total of 797,002 patients were included for analysis. Overall, 27.57% (95% CI 27.47-27.67) of patients had preoperative anemia, which varied by gender, age, regions, and type of operation. Patients who were female, age over 60 years old, from South China, from provinces with lower per capita GDP, underwent operations on the lymphatic and hematopoietic system, with laboratory abnormalities were more likely to have a high risk of preoperative anemia. Among patients with preoperative anemia, 5.16% (95% CI 5.07-5.26) received red blood cell transfusion, 7.79% (95% CI 7.67-7.91) received anemia-related medications such as iron, erythropoietin, folic acid or vitamin B12, and 12.25% (95% CI 12.10-12.40) received anemia-related therapy (red blood cell transfusion or anemia-related medications) before operation. The probability of preoperative RBC transfusion decreased by 54.92% (OR 0.46, 95% CI 0.46-0.47) as each 10-g/L increase in preoperative hemoglobin. Patients with preoperative hemoglobin less than 130 g/L was associated with longer hospital stay and more hospital costs. Patients with severe preoperative anemia given iron preoperatively had lower intra/post-operative RBC transfusion rate, shorter length of stay and less hospitalization costs, but no similar correlation was found in patients with mild and moderate preoperative anemia and patients given erythropoietin preoperatively. INTERPRETATION: Our present study shows that preoperative anemia is currently a relatively prevalent problem that has not been fully appreciated in China. More researches will be required to optimize the treatment of preoperative anemia. FUNDING: National Natural Science Foundation of China and the Logistics Support Department of the Central Military Commission.

Clinical Indications of Recombinant Human Erythropoietin in a Single Center: A 10-Year Retrospective Study.

In the 1980s, recombinant human erythropoietin (rhEPO) began to be used in clinical practice. In this study, the clinical application of rhEPO from single-center in recent ten years was reviewed, and the scope of indications and clinical efficacy were evaluated. The medical records of 35829 in-patients who were treated with rhEPO in the first Medical Center of the Chinese PLA General Hospital from 2009 to 2018 were collected. According to the scope of indications approved by CFDA (China Food and Drug Administration), curative effect and off-label of rhEPO were analyzed. Of the 35829 patients, 19013 (53.1%) were male and 16816 (46.9%) were female, with an average age of (52.1 ± 18.6) years. The usage of rhEPO is increasing year by year. The overall effective rate was 53.1%. The number of patients who met the indications accounted for 67.2%, and the effective rate patients with indications and Off-label were 48.8% and 50.7%. Among the patients with irregular use of rhEPO perioperative imperfect laboratory examination patients accounted for the highest proportion (7.1%). The volume of RBC(s) (red blood cell(s)) transfusion in patients with rhEPO was significantly less than that in patients without rhEPO (p<0.05). The use of rhEPO Off-label is very common and has a certain curative effect. It can be used as evidence support for the update of the scope of indications. In addition, There are still irregular use of rhEPO and transfusion in clinic. The unreasonable use of rhEPO and transfusion should be further standardized to ensure the safety and effectiveness.

Risks associated with perioperative anaemia and perioperative blood transfusion in patients undergoing neurosurgical operation.

OBJECTIVE: To investigate the prevalence of preoperative anaemia and the risks associated with perioperative anaemia and blood transfusion in patients who underwent neurological surgery. BACKGROUND: Perioperative anaemia has an important impact on neurosurgery patients. The prevalence and risks of perioperative anaemia and blood transfusion in Chinese patients are still unknown. METHODS: Logistic regression was used to predict adverse outcomes of red blood cell (RBC) transfusion and different levels of anaemia. Anaemia and transfusion were compared as independent variables by using a 1:1 match on propensity score. RESULTS: The prevalence of preoperative anaemia in neurosurgical patients was 20.05%; 10.33% patients received RBC transfusion. Perioperative RBC and plasma transfusion rates (P < .001) and average hospital costs (P = .0365) were higher in preoperative moderate-to-severe anaemia patients than in no anaemia patients. Perioperative RBC transfusion patients had longer hospital length of stay (LOS) (P < .001) and higher average hospital costs (P < .001) than no-transfusion patients. The rates of return to the operating room (OR) within 30 days and intensive care unit stay did not demonstrate any significant difference in anaemia and transfusion cohorts, respectively. CONCLUSION: The status of preoperative anaemia in Chinese neurosurgical patients is associated with increased transfusion rates and hospital costs. Perioperative RBC transfusion is associated with increased length and cost of hospitalisation.

A single-center investigational study of CD36 antigen deficiency and platelet alloantibody distribution in different populations in Northern China as well as platelet alloantibodies effect on pregnancy.

BACKGROUND: Platelet antibodies can lead to clinical diseases such as platelet transfusion refractoriness (PTR), fetal/neonatal alloimmune thrombocytopenia (FNAIT), etc. This study is aimed at understanding CD36 expression, platelet alloantibody distribution in different populations in Northern China, and effects of platelet alloantibodies on pregnancy. STUDY DESIGN AND METHODS: Whole blood samples of 612 subjects including hematological patients, pregnant women, and blood donors were collected at a single center, then CD36 expressions were determined, followed by platelet antibody screening and characterization of platelet antibody specificity. A retrospective analysis was performed in 1552 pregnant women admitted to Department of Obstetrics, in order to investigate FNAIT occurrence. RESULTS: Rate of CD36 deficiency expression was 2.12% (13/612), all cases exhibited type II deficiency without type I deficiency being detected, and such rate is lower than that in Southern China (3.43%), Japanese (4.87%) and in the black people (4.18%), and higher than that in the White people (0.09%). Positive rates of platelet antibody screening in hematological patient group (6.86%, 14/204) and in pregnant women group (6.31%, 13/206) are higher than that in blood donor group (0.49%, 1/202), P < .01. Out of 1552 pregnant women, there were not children with FNAIT. CONCLUSION: The frequency of CD36 deficiency in northern China was low, all of them were type II deficiency, and no CD36 antibody was detected. It is speculated that the risk of immune-related thrombocytopenia caused by CD36 deficiency in this population is very low. Platelet antibodies should be monitored early in patients with hematological and multiple miscarriages pregnant.

Prevalence and Specificity of Red Blood Cell Alloantibodies in Patients from China During 1994-2013.

OBJECTIVE: To analyze the data about red blood cell alloantibodies in patients from mainland China and to provide evidence for formulating a management guideline. METHODS: The Chinese and English literatures about Chinese patients in mainland China published in periodicals were retrieved by CHKD, CNKI, CMJD and PubMed using the key words as unexpected antibody, irregular antibody, blood group antibody, hemolytic transfusion reaction (HTR), hemolytic disease of the newborn (HDN), hemolytic disease of the fetus and newborn (HDFN). RESULTS: A total of 5582 red blood cell alloantibodies were retrieved from 4800 patients. The average prevalence of alloantibody in 89 retrospective analysis reports was 0.34 %. Among all study patients, the 10 most common antibodies were anti-E (33.9%), anti-D (18.3%), anti-c (10.9%), anti-M (9.9%), anti-C (8.1%), anti-e (4.8%), anti-Le(a) (3.4%), anti-P1 (2.0%), anti-Mur (1.6%), and anti-Jk(a) (1.2%). Out of all 136 patients with HTR, the most frequentl alloantibodies were Rhesus antibodies (71.7%), and other antibodies included anti-Jk(b) (5.9%), anti-Le(a) (5.1%), anti-Jk(a) (3.7%), anti-M (1.5%), and anti-Mur (1.5%). A total of 644 alloantibodies contributing to HDFN come primarily from the Rhesus (93.1%) and MNS (6.0%) blood group systems. CONCLUSION: The postnatal Rh prophylaxis should become a routine procedure in mainland China. The use of blood matched for C, E, c, e, Jk(a) and Jk(b) should be recommended for Chinese patients with a history of multiple transfusions. Patients with MNS alloantibodies should be given sufficient attention, and Mur+ red blood cells should be included in antibody screening panels.

[Influence of "dosage effect" on unexpected antibody identification].

OBJECTIVE: This study was to investigate the influence of "dosage effect" on unexpected antibody identification and explore its condition, scope and regularity. METHODS: A total of 40 blood recipient samples containing definite unexpected antibodies were selected by column agglutination technology, then AB fresh plasma was used to dilute the samples to obtain different concentrate liquid. After selecting panel cells which show positive with corresponding unexpected antibody in the serum, "single dosage" antigens were distinguished from "double dosage" ones, and then the antigen-antibody reactions were observed between "single dosage" panel cells and respective diluted recipient samples (by column agglutination technology). It's believable that the highest concentration which retains a negative result was choose to evaluate the agglutination strength between "double dosage" panel cells and diluted unexpected antibody, and to observe the difference happened at different "dosage" antigens with unexpressed antibody. RESULTS: Among 40 diluted recipient samples detected by column agglutination technology, the "dosage effect" appeared in 31 diluted samples. There were 30 samples in which the unexpected antibody agglutinated "double dosage" antigens ≤ 2+, while "single dosage" antigens negative. It appeared in another 1 diluted sample, in which the unexpected antibody agglutinated "double dosage" antigens 3+. There were 9 diluted samples in which the unexpected antibody agglutinated panel cells showing negative results (strength was between 1+-3+ before dilution). CONCLUSIONS: When the unexpected antibodies in Rh, MNS, Kidd, Duffy agglutinated "double dosage" antigens ≤ 2+ (by column agglutination technology) , "single dosage" antibody reaction maybe weaken, even be negative, and it may cause the "dosage effect" to interfere the unexpected antibody identification. The "dosage effect" appears in Rh, MNS, Kidd, Duffy blood system usually.

Effects of hydroformylation treatment on the storage time and blood group antigen expressions of reagent red blood cells.

OBJECTIVE: To evaluate the effects of hydroformylation treatment on the storage time and blood group antigen expressions of reagent red blood cells (RBCs). MATERIAL AND METHODS: RBCs from healthy donors were treated by using various final concentrations of paraformaldehyde (0.01%, 0.02%, 0.05%, 0.1%, 0.2%, 0.5% and 1.0%) and glutaraldehyde (0.01%, 0.025%, 0.05%, 0.1%, 0.2%, 0.5% and 1.0%), and one aliquot was used as control (untreated with aldehydes). Supernatant free hemoglobin (FHb) levels in all groups stored at 4 °C were detected every week, and the optimal procedure was selected. Expression of blood group antigens on RBCs treated by the optimal procedure was determined, and the total scores of blood group antigens were calculated. RESULTS: 0.2%, 0.5% and 1.0% Glutaraldehyde groups were ruled out directly due to serious crosslinking and aggregation of RBCs. As the extension of time, FHb levels in other 11 groups gradually increased (p<0.01 or p<0.05). FHb level in 0.025% glutaraldehyde group was significantly lower than that in other groups after 13 weeks (p<0.01), and the antigen strength of Fy(b), Jk(b), and Le(b) decreased slightly compared with those before treatment and storage (p<0.05), and there was no significant change for antigen strength of A, B, D, C, E, c, e, M, N, S, s, k, P1, Fy(a), Jk(a), and Le(a) (p>0.05). CONCLUSION: 0.025% Glutaraldehyde treatment can provide optimal protection for the membrane of RBCs and keep hemolysis at a low level after 13 weeks storage, and the majority of blood group antigen systems are not significantly affected, and the slight decline of Fy(b), Jk(b), and Le(b) antigen strength was acceptable for classical serological tests.

[Serological characteristics and transfusion efficacy evaluation in 61 cases of autoimmune hemolytic anemia].

This study was aimed to analyze the serological characteristics, efficacy and safety of incompatible RBC transfusion in patients with autoimmune hemolytic anemia (AIHA). The patients with idiopathic or secondary AIHA were analyzed retrospectively, then the serological characteristics and the incidence of adverse transfusion reactions were investigated, and the efficacy and safety of incompatible RBC transfusion were evaluated according to the different autoantibody type and infused different RBC components. The results showed that out of 61 cases of AIHA, 21 cases were idiopathic, and 40 cases were secondary. 8 cases (13.1%) had IgM cold autoantibody, 50 cases (82.0%) had IgG warm autoantibody, and 3 cases (4.9%) had IgM and IgG autoantibodies simultaneously. There were 18 cases (29.5%) combined with alloantibodies. After the exclusion of alloantibodies interference, 113 incompatible RBC transfusions were performed for 36 patients with AIHA, total efficiency rate, total partial efficiency rate and total inefficiency rate were 56.6%, 15.1% and 28.3%, respectively. Incompatible RBC transfusions were divided into non-washed RBC group and washed RBC group. The efficiency rate, partial efficiency rate and inefficiency rate in non-washed RBC group were 57.6%, 13.0% and 29.4%, respectively. The efficiency rate, partial efficiency rate and inefficiency rate in washed RBC group were 53.6%, 21.4% and 25.0%, respectively. There was no significant difference of transfusion efficacy (P > 0.05) in two groups. Incompatible RBC transfusions were also divided into IgM cold autoantibody group and IgG warm autoantibody group. The efficiency rate, partial efficiency rate and inefficiency rate in IgM cold autoantibody group were 46.2%, 30.8% and 29.4%, respectively. The efficiency rate, partial efficiency rate and inefficiency rate in IgG warm autoantibody group were 56.7%, 13.4% and 29.9%, respectively. There was no significant difference of transfusion efficacy (P > 0.05 ) in two groups. Hemolytic transfusion reaction was not observed in all incompatible RBC transfusions. It is concluded that the same ABO type of non-washed RBC transfusion and O type washed RBC transfusion are all relatively safe for the AIHA patients with severe anemia after the exclusion of alloantibodies interference. There is no significant difference of transfusion efficacy in two groups. The same ABO type of non-washed RBC transfusion is more convenient and efficient than washed RBC transfusion, and excessive use of type O RBCs can also be avoided.

Establishment and performance assessment of preparation technology of internal quality control products for blood transfusion compatibility testing.

The aim of this study was to establish and to optimize the preparation technology of whole blood internal quality control (IQC) products for blood transfusion compatibility testing. Several B-type RhD-negative blood samples collected from healthy donors were mixed. Two groups of whole blood IQC products, namely, the preservative solution group (PS group) and the saline group, were prepared. The agglutination intensity of IQC sample red cells and anti-B antibody, IgM anti-A antibody and reverse-typing A cell, IgG anti-D and O-type RhD-positive red cells, as well as free hemoglobin concentration in the supernatant of the two groups were detected. The erythrocytes in both groups were damaged to a certain extent during storage, but no evident (above moderate) hemolysis was observed in the stored sample within 42 days. The red cells remained structurally complete and the reaction activity of IgG anti-D reagent remained generally unchanged (P>0.05). Although the reaction activity oscillation of IgM anti-A reagent was observed, the agglutination intensity varied within an acceptable range of 1+. No difference was observed between the preparation methods of the samples, i.e., between the erythrocyte washed with saline and the one washed with red cell preservative solution (P>0.05). The long shelf life, low variance between tubes and stable antigen-antibody reaction activity of the whole blood IQC products prepared using the proposed method can meet the requirements of blood transfusion compatibility testing.

[Inside quality control for whole blood preservation performed at blood transfusion compatibility testing laboratory].

This study was aimed to establish the technique for preparation and storage of internal quality control pro-ducts by using existing blood sample resources of blood transfusion compatibility testing laboratory. 24 healthy blood donors with group A and RhD-positive were randomly selected, and 4 ml venous blood from these donors were collected, respectively. Based on the use of anticoagulant type, whether to add red blood cell preservation solution and the samples stored at room temperature for 1 or 2 hours daily, 24 specimens were randomly divided into 8 groups by using factorial design methodology. All samples in tube with cap were stored at 4 degrees C, and placed at room temperature for 1 or 2 hours daily. ABO, RhD blood group (recorded on the agglutination strength of the forward and reverse typing), IgM anti-B antibody titer, and free hemoglobin concentration in the supernatant for all samples were detected at 0, 7, 14, 21, 28, 35 days of products preservation. The results indicated that the red blood cell damage from the group used anticoagulants ACD-B and added the MAP red blood cell preservation solution and placed at room temperature 1 hour daily (recorded as A2B2C1 group) was kept minimal, and FHb concentration and FHb increments at each time point were the lowest (p < 0.01), the FHb concentration on 35th day was only (24.5 +/- 84.5) mg/L. There was no significant change of A antigen, D antigen and IgM anti-B antibody response activity and stability in A2B2C1 group during storage for 35 days (p > 0.05). In conclusion, blood transfusion compatibility testing laboratory can use A2B2C1 program established by this study to prepare relatively stable modified whole blood internal quality control products in the existing conditions, which can be effectively preserved and meet the requirements of internal quality control for blood transfusion compatibility testing.

[Establishment of genotyping method for fetal ABO group from pregnant maternal peripheral blood].

This study was aimed to establish a genotyping method to detect ABO group gene of fetus from peripheral blood of pregnant women for prenatal diagnosis of hemolytic disease of newborn (HDN) resulting from ABO blood group incompatibility. 4 pairs of primers were designed according to ABO blood group gene DNA and mRNA sequences. 20 plasma DNA samples from healthy donors were extracted and amplified to explore the best conditions for plasma DNA extraction and PCR amplification. The O group plasma DNA was mixed with A group or B group plasmas by the ratios of 1:1, 2:1, 4:1, 8:1, 10:1, 20:1, 40:1, 100:1 to simulate the status of mixed ABO gene from pregnant maternal blood and to establish the mixed blood group ABO genotyping technology. The pregnant maternal blood samples with more than 30 weeks of gestation were selected for detecting the fetal ABO blood group genotype. The blood samples should be taken as possible as after birth for identification of ABO blood group and evaluation of sensitivity and accuracy of fetal ABO blood group genotyping technology through peripheral blood of pregnant women. The results indicated that the minimal amount of template DNA from single blood plasma for accuracy identification was at least about 0.625 ng, the DNA amount extracted from 500 microl of plasma could meet the requirement for PCR amplification. When the proportion of O group plasma DNA in mixed plasma DNA was