BACKGROUND

Pre-transfusion testing is done to avoid transfusion morbidity from unexpected RBC antibodies. Available commercial kits from Western brands may not consider racial differences in antibody frequencies between East/Southeast Asians and Western populations. The limited number of blood banks in the Philippines precludes research on RBC antibody screening and identification in the country.

This study aimed to compare RBC antibody screening and identification methods in patients at a tertiary hospital in the Philippines, assess the frequency of major blood group antibodies using both techniques, and review clinical histories of discrepant and nonspecific cases.

Retrospective review showed 118 cases with both screening and identification tests using both conventional tube-based technique and column agglutination or gel-based technique. Antibody frequencies and discrepant or nonspecific results were recorded. Concordance rates were calculated, and differences between the two methods were analyzed using 95% confidence interval (95% CI). Clinical histories of discrepant and nonspecific cases were also reviewed.

The most frequent major blood group was Rh (41 cases or 34.7%), followed by MNS (34 cases or 28.8%) and Kidd (15 cases or 12.7%). The most common antibody was Anti-E (24 cases or 20.3%), followed by Anti-Mia (19 cases or 16.1%), and Anti-M and Anti-c (12 cases each, or 10.2% each). The concordance rate for screening was statistically significant at 72%. Concordance rate for identification was 59.3%, with significant difference in identifying Anti-Mia. Clinical histories for discrepant or nonspecific cases showed previous transfusions, pregnancy, lymphoproliferative conditions, and certain medications.

Statistically significant differences between the two methods were found, with the gel-based technique identifying more Anti-Mia cases. Negative results from the tube-based method do not fully exclude Anti-Mia. These discrepancies highlight the benefit of using both methods for comprehensive RBC antibody screening and identification, done as a complement to the other.

Objective To propose the blood detection strategies for human immunodeficiency virus (HIV) among blood donors, and provide reference for the detection, early diagnosis and transmission blocking of HIV. Methods A total of 117 987 blood samples from blood donors were screened using the third- and fourth-generation ELISA HIV detection reagents. Western blot analysis was used to verify the reactive results of the third-generation reagent alone, or both the third-generation and fourth-generation reagents. HIV nucleic acid test was carried out for those with negative test results of the third- and fourth-generation reagents. For those with positive results of the fourth-generation reagent only, nucleic acid test followed by a confirmatory test by Western blot analysis was carried out. Results 117 987 blood samples from blood donors were tested by different reagents. Among them, 55 were tested positive by both the third- and fourth-generation HIV detection reagents at the same time, accounting for 0.047% and 54 cases were confirmed HIV-positive by Western blot analysis, and 1 case was indeterminate, then turned positive during follow-up testing. 26 cases were positive by the third-generation reagent test alone, among which 24 cases were negative and 2 were indeterminate by Western blot analysis. The band types were p24 and gp160 respectively detected by Western blot analysis, and were confirmed to be HIV negative in follow-up testing. 31 cases were positive by the fourth-generation HIV reagent alone, among which 29 were negative by nucleic acid test, and 2 were positive according to the nucleic acid test.Western blot analysis was used to verify that the two cases were negative. However, after 2~4 weeks, the results turned positive when the blood sample was retested by Western blot analysis during the follow-up of these two cases. All the specimens that were tested negative by both the third- and fourth-generation HIV reagents were validated negative by HIV nucleic acid test. Conclusion A combined strategy with both third- and fourth-generation HIV detection reagents can play a complementary role in blood screening among blood donors. The application of complementary tests, such as nucleic acid test and Western blot analysis, can further improve the safety of blood supply, thus contributing to the early diagnosis, prevention, transmission and treatment of blood donors potentially infected by HIV.
Humans ; HIV Infections/diagnosis* ; HIV Antibodies ; Blood Donors ; HIV-1 ; Blotting, Western ; Nucleic Acids

OBJECTIVE: To establish the diagnostic process of low titer blood group antibody in the occurrence of adverse reactions of hemolytic transfusion. METHODS: Acid elusion test, enzyme method and PEG method were used for antibody identification. Combined with the patient's clinical symptoms and relevant inspection indexes, the irregular antibodies leading to hemolysis were detected. RESULTS: The patient's irregular antibody screening was positive, and it was determined that there was anti-Le^a antibody in the serum. After the transfusion reaction, the low titer anti-E antibody was detected by enhanced test. The patient's Rh typing was Ccee, while the transfused red blood cells were ccEE. The new and old samples of the patient were matched with the transfused red blood cells by PEG method, and the major were incompatible. The evidence of hemolytic transfusion reaction was found. CONCLUSION Antibodies with low titer in serum are not easy to be detected, which often lead to severe hemolytic transfusion reaction.
Humans ; Blood Transfusion ; Transfusion Reaction/prevention & control* ; Hemolysis ; Blood Group Antigens ; Erythrocyte Transfusion ; Antibodies ; Isoantibodies ; Blood Group Incompatibility

OBJECTIVE: To investigate the distribution of irregular blood group antibodies in patients with malignant tumors, and to analyze the relationship between it and efficacy of blood transfusion in patients. METHODS: 5 600 patients with malignant tumors treated in Shanxi Bethune Hospital from January 2019 to December 2021 were selected as the research subjects. All patients received blood transfusion, and cross matching test was conducted before blood transfusion, irregular antibody results of patients were tested; the irregular distribution of blood group antibodies was observed, and the relationship between it and efficacy of blood transfusion in patients was analyzed. RESULTS: Among 5 600 patients with malignant tumors, 96 cases were positive for irregular antibody, and the positive rate was 1.71%; the main blood group systems involved in the irregular antibody positive of 96 patients with malignant tumors were RH, MNSs and Duffy system, among which Rh blood group was the most common, and the proportion of anti-E was the highest; among the malignant tumor patients with positive blood group irregular antibody, the proportion of female was higher than that of male; the proportion of patients aged >60 years was the highest, followed by patients aged >40 and ≤50 years, and the proportion of patients aged 18-30 years was the lowest; the patients with positive blood group irregular antibody were mainly in blood system (including lymphoma), digestive system, reproductive and urinary system; the positive rate of irregular antibody of patients in the ineffective group was higher than that of patients in the effective group, the difference was statistically significant (P<0.05). Logistic regression analysis results showed that, irregular antibody positive was a risk factor for ineffective blood transfusion in patients with malignant tumor (OR>1, P<0.05). CONCLUSION The irregular blood group antibody positive of patients with malignant tumor are mostly female, and the proportion of patients aged >60 is the highest, which is mainly distributed in malignant tumors of blood system, digestive system and urogenital system, and the positive blood group irregular antibody is related to the efficacy of blood transfusion in patients.
Humans ; Male ; Female ; Blood Transfusion ; Blood Group Antigens ; Rh-Hr Blood-Group System ; Antibodies ; Neoplasms/therapy* ; Isoantibodies

Objective To investigate the effect of blood group serology and polymerase chain reaction with sequence-specific primers (PCR-SSP) on identification and genotyping of ambiguous ABO blood group. Methods Eighty suspicious ABO blood group samples were identified by serology and polymerase chain reaction with sequence-specific primers (PCR-SSP). The final blood group type and the strategy of the transfusion of each case were determined according to the results of serology and PCR-SSP. Results 40 cases were confirmed to be subtypes, and the remaining 40 cases were normal types with weakened antigens or missing antibodies due to other reasons. The results of molecular genetic blood group typing based on PCR-SSP were 41 cases of subtypes (There were 3 discrepancies between two methods: one was Ael identified by serological methods, while its gene type was O2O2; one was common type O, while its gene type was BO1; one was type A, while its gene type was AB.) and 39 cases of normal ones. Conclusion Genotyping technology combined with serological typing has an important significance in identification of ABO blood groups.
ABO Blood-Group System/genetics* ; Genotype ; Polymerase Chain Reaction ; Antibodies ; DNA Primers

The emerging of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused COVID-19 pandemic. The first case of COVID-19 was reported at early December in 2019 in Wuhan City, China. To examine specific antibodies against SARS-CoV-2 in biological samples before December 2019 would give clues when the epidemic of SARS-CoV-2 might start to circulate in populations. We obtained all 88,517 plasmas from 76,844 blood donors in Wuhan between 1 September and 31 December 2019. We first evaluated the pan-immunoglobin (pan-Ig) against SARS-CoV-2 in 43,850 samples from 32,484 blood donors with suitable sample quality and enough volume. Two hundred and sixty-four samples from 213 donors were pan-Ig reactive, then further tested IgG and IgM, and validated by neutralizing antibodies against SARS-CoV-2. Two hundred and thirteen samples (from 175 donors) were only pan-Ig reactive, 8 (from 4 donors) were pan-Ig and IgG reactive, and 43 (from 34 donors) were pan-Ig and IgM reactive. Microneutralization assay showed all negative results. In addition, 213 screened reactive donors were analyzed and did not show obviously temporal or regional tendency, but the distribution of age showed a difference compared with all tested donors. Then we reviewed SARS-CoV-2 antibody results from these donors who donated several times from September 2019 to June 2020, partly tested in a previous published study, no one was found a significant increase in S/CO of antibodies against SARS-CoV-2. Our findings showed no SARS-CoV-2-specific antibodies existing among blood donors in Wuhan, China before 2020, indicating no evidence of transmission of COVID-19 before December 2019 in Wuhan, China.
Humans ; Antibodies, Viral ; Blood Donors ; China/epidemiology* ; COVID-19/immunology* ; Immunoglobulin G ; Immunoglobulin M ; Pandemics ; SARS-CoV-2

OBJECTIVE: To explore the predictive value of four items of new thrombus markers combined with conventional coagulation tests for thrombosis in antiphospholipid syndrome. METHODS: A total of 121 antiphospholipid syndrome (APS) patients who hospitalized at Peking University People's Hospital from March 2022 to January 2023 were selected and divided into thrombus group (50 cases) and nonthrombus group (71 cases) according to whether thrombosis occurred. The differences of laboratory characteristics including antiphospholipid antibodies were compared between the thrombotic and non-thrombotic groups. Chemiluminescent immunoassay was used to detect thrombomodulin (TM), thrombin-antithrombin complex (TAT), Plasmin-α2 plasmin inhibitor complex (PIC), and tissue plasminogen activator inhibitor complex (t-PAIC) in plasma from venous. The independent risk factors of thrombosis in patients with APS were determined using binary Logistic regression. Receiver operating characteristic (ROC) curve analysis was applied to evaluate the efficacy of each index on the prediction of thrombosis. RESULTS: Compared with the patients without thrombosis, the patients with thrombosis were older [49 (32, 64) years vs. 36 (32, 39) years, P < 0.05]. The percentages of male, smoking, hypertension, and global antiphospholipid syndrome score (GAPSS)≥10 in the patients with thrombosis were significantly higher than those in the patients without thrombosis (P < 0.05). The positive rates of anticardiolipin antibody (aCL) and lupus anticoagulant (LA) in the thrombotic group were significantly higher than those in the non-thrombotic group (P < 0.05), and the levels of prothrombin time, activated partial thromboplastin time, fibrinogen, fibrin degradation product in the thrombotic group were significantly higher than those in the non-thrombotic group (P < 0.05).Among the thrombosis group, venous thrombosis accounted for 19 (38.00%), including deep vein thrombosis (16, 84.21%) and pulmonary embolism accounted (5, 26.32%); Arterial thrombosis accounted for 35 (70.00%), including myocardial infarction (6, 17.14%) cerebral infarction (30, 85.71%). The patients in the thrombotic group had significantly greater TM levels than those in the non-thrombotic group (P < 0.05).There were no significant dif-ferences between the two groups in TAT (Z=-1.420, P=0.156), PIC (Z=-0.064, P=0.949), and t-PAIC (Z=-1.487, P=0.137). Univariate and binary Logistic regression analysis of relevant variables showed that advanced age [OR=1.126, P=0.002], elevated TM [OR=1.325, P=0.048], prolonged prothrombin time (PT) [OR=4.127, P=0.008] were independent risk factors for thrombosis in the patients with APS. ROC curve analysis of the above three independent risk factors showed that the combined detection of age, PT and TM had the highest Yoden index (0.727) and sensitivity (83.0%), with a specificity of 89.7%. CONCLUSION TAT, PIC, TM, and t-PAIC may reflect thrombus formation from the coagulation system, fibrinolysis system, and endothelial system. The combined of age TM and PT is superior to the application of a single marker, which has diagnostic value for the early identification of APS thrombosis.
Humans ; Male ; Antiphospholipid Syndrome/diagnosis* ; Tissue Plasminogen Activator ; Thrombosis/etiology* ; Antibodies, Antiphospholipid/analysis* ; Blood Coagulation Tests/adverse effects*

OBJECTIVE: To establish a new method for synthesizing Lewis blood group antigens, that is, the mimotopes of Lewis blood group antigens were screened by using an alpaca phage display nanobody library. METHODS: We selected mimotopes of the Lewis a (le^a) antigen by affinity panning of an alpaca phage display nanobody library using a monoclonal anti-le^a antibody. Enzyme-linked immunosorbent assay (ELISA) was used to test the affinity of the positive clones for the monoclonal anti-le^a antibody, and the high-affinity positive clones were selected for sequencing and synthesis. Finally, the sensitivity, specificity and reactivity of the synthesized le^a mimotope in clinical samples were verified by ELISA. RESULTS: A total of 96 phage clones were randomly selected, and 24 were positive. Fourteen positive clones with the highest affinity were selected for sequencing. The result showed that there were 5 different sequences, among which 3 sequences with the highest frequency, largest difference and highest affinity were selected for expression and synthesis. The sensitivity and specificity of le^a mimic antigen by ELISA showed that, the minimum detection limit of gel microcolumn assay (GMA) and ELISA method were 25 times different, and the le^a mimic antigen had no cross reacted with the other five unrelated monoclonal antibodies(P<0.001). Finally, 30 clinical plasma samples were analyzed. The mean absorbance of the 15 positive plasma samples was significantly higher than that of the 15 negative plasma samples (P=0.02). However, the positive signal values of the clinical samples were much lower than those of the monoclonal antibodies. CONCLUSION A new method of screening le^a mimic antigen by using alpaca phage nanoantibody library has been established, which is expected to realize the screening of le^a mimotopes, thus realizing the application of high-sensitivity detection methods such as ELISA and chemiluminescence in blood group antibody identification.
Animals ; Antibodies, Monoclonal ; Antineoplastic Agents, Immunological ; Bacteriophages ; Blood Group Antigens ; Camelids, New World ; Enzyme-Linked Immunosorbent Assay/methods* ; Epitopes ; Humans ; Lewis Blood Group Antigens ; Peptide Library

OBJECTIVE: To investigate the effectiveness and safety of low concentration dithiothreitol (DTT) in removing the interference of monoclonal anti-CD38 on transfusion compatibility testing, and develop a reasonable clinical transfusion strategy. METHODS: The blood type, direct antiglobulin testing (DAT) and antibody screening were tested according to standard methods. Antibody screening cells and donor's red blood cells were treated by DTT 0.2, 0.1, 0.05, 0.02, 0.01 and 0.005 mol/L, and antibody screening and cross-matching of serums after monoclonal anti-CD38 treatment were performed by anti-human globulin card. RESULTS: The 0.01 mol/L DTT at 37℃ for 30 minutes could remove the effect of monoclonal anti-CD38 on antibody screening and cross-matching, meanwhile retain their effectiveness in detecting anti-K, anti-LW, anti-JMH, anti-Lu^b, anti-e, anti-Di^a and anti-Jk^a alloantibodies. All the 10 patients had no acute or delayed haemolytic transfusion reactions and their routine blood tests showed that the red blood cells transfusion was effective. CONCLUSION The 0.01 mol/L DTT is a safe and effective method for removing the interference of monoclonal anti-CD38 with transfusion compatibility testing, while retaining the ability to detect most alloantibodies.
Antibodies, Monoclonal/pharmacology* ; Blood Grouping and Crossmatching ; Blood Transfusion ; Dithiothreitol/pharmacology* ; Erythrocytes ; Humans ; Isoantibodies/pharmacology*

OBJECTIVE: To investigate the clinical and immunological features of cardiac involvement in patients with anti-synthetase syndrome (ASS). METHODS: In the study, 96 patients diagnosed with ASS hospitalized in the Department of Rheumatology and Immunology, Peking University People's Hospital from April 2003 to November 2020 were included. The patients were divided into two groups according to whether they were accompanied with cardiac involvement. Demographic features, clinical characteristics (Gottron's sign/papules, muscle damage, etc.), comorbidities, laboratory indices (creatine kinase, inflammatory indicators, immunoglobulin, complement, lymphocyte subset, autoantibodies, etc.) were collected and the differences between the two groups were analyzed statistically. RESULTS: The prevalence of cardiac involvement in the patients with ASS was 25.0% (24/96). The ASS patients complicated with cardiac involvement presented with elevated cardiac troponin I (cTnI, 75.0%, 18/24), pericardial effusion (33.3%, 8/24), reduction of left ventricular function (33.3%, 8/24) and valves regurgitation (33.3%, 8/24). The age of onset of the patients with cardiac involvement was older than that of the patients without cardiac involvement [(54.58±10.58) years vs. (48.47±13.22) years, P=0.043). Arthritis was observed less frequently in the patients with cardiac involvement than those without cardiac involvement (37.5% vs. 61.1%, P=0.044). In addition, rapidly progressive interstitial lung disease (54.2% vs. 30.6%, P=0.037) was observed more frequently in the patients with cardiac involvement than those without cardiac involvement. As compared with the ASS patients without cardiac involvement, C-reactive protein (CRP) [(13.55 (8.96, 38.35) mg/L vs. 4.60 (1.37, 17.40) mg/L, P=0.001], and lactate dehydrogenase (LDH) [408.0 (255.0, 587.0) U/L vs. 259.5 (189.8, 393.8) U/L, P=0.007] were significantly higher in the patients with cardiac involvement. Anti-Ro-52 antibody was detected more commonly in the ASS patients with cardiac involvement compared with the patients without cardiac involvement (91.7% vs. 69.4%, P=0.029). No significant differences were found in the comorbidities, alanine transaminase (ALT), aspartate transaminase (AST), creatine kinase (CK), erythrocyte sedimentation rate (ESR), ferritin (Fer), immunoglobulin G (IgG), complement 3 (C3), complement 4 (C4), lymphocyte subset between the two groups. CONCLUSION Cardiac involvement is common in ASS, mainly manifested as myocardial damage. It is necessary to be aware of cardiac complications in patients with elevated CRP, elevated LDH and positive anti-Ro-52 antibody.
Adult ; Aged ; Antibodies, Antinuclear ; Autoantibodies ; Blood Sedimentation ; C-Reactive Protein ; Heart Diseases/complications* ; Humans ; Immunoglobulin G ; L-Lactate Dehydrogenase ; Middle Aged ; Myositis/diagnosis*