Antibody drug conjugates (ADCs) are an emerging class of targeted therapeutics with the potential to improve therapeutic index over the traditional chemotherapy. However, it is difficult to control the site and stoichiometry of conjugation in mAb, typically resulting in heterogeneous mixtures of ADCs that are difficult to optimize. New methods for site-specific drug attachment allow development of more homogeneous conjugates and control of the site of drug attachment. In this article, the new literature on development of ADCs and site-specific ADCs is reviewed. In addition, we summarized the various strategies in production of site-specific ADCs.
Antibodies, Monoclonal ; chemistry ; Antibody Specificity ; Binding Sites, Antibody ; Immunoconjugates ; chemistry

Development of luminex-based solid phase assays enables advanced measurement of HLA antibody with sensitivity, specificity, and increasing knowledge of unacceptable antigens. In this review, we described the principle of the luminex-based assay and its current applications for organ transplantation including C1q assay, calculated panel reactive antibody, and virtual cross-matching. We also discussed the technical aspects and limitations for clinical utilization. The variables related to measurement of HLA antibody specificities and their clinical relevance remain unclear, therefore the interpretation of results requires comprehensive knowledge and clinical information in critical cases.
Antibody Specificity ; Immunoassay* ; Organ Transplantation* ; Sensitivity and Specificity ; Transplantation ; Transplants*

BACKGROUND: Determination of antibody specificity using antigram spread sheet requires experience and knowledge on in vitro characteristics of red cell antibodies, time-consuming, and still subjective to human error. A computer-based antibody identification system was developed to overcome these disadvantages. METHODS: Decision support system program for antibody identification was designed using Visual Basic 5.0 for Dade Data-cyte Plus. This system integrates the reaction patterns of saline, 37degrees C albumin, antiglobulin, 4degrees C saline enzyme treated and user-defined phases and lists the antibodies according to the probability. 115 irregular antibodies previously confirmed by standard manual method reanalyzed with this program. RESULTS: In 111 of 115 cases (96.5%), this system produced the same results with the manual identification. In two cases, of not matched 4 cases the computer program suggested additional antibodies and in one case, the computer program detected previous human error. In the other case, antibody identification was possible only after further tests including selective adsorption of multiple antibodies. CONCLUSION: The decision support system was rapid and easy and showed good concordance rate when compared with manual antibody identificaion results. In addition, human error could be reduced. Decision support system for antibody identification could be used in small blood banks by less experienced staffs.
Adsorption ; Antibodies ; Antibody Specificity ; Blood Banks ; Expert Systems ; Humans

BACKGROUND: HLA antisera are procured mainly from placental blood or blood of multiparous women. The latter has a merit that a large volume of antisera could be obtained, once the antisera are found to be of good quality. METHODS: A total of 1,437 multiparous blood donors were screened for the presence of anti- HLA antibodies. After the first screening with 20 panel cells, initially reactive sera were re- screened with 30 panel cells. RESULTS: Of 1,437 sera, 50 sera (3.5%) were reactive to both the first and the second screening panel cells. Among 50 sera, 25 (50.0%) sera could be assigned for their antibody specificity with r value of 0.8 or more. Only 14 samples (1.0%) showed reactivity to two or more panels with same antigen specificity and strength index of 80% or more. Four donors repeatedly donated blood with specificities of A24, A26, B7, and B7+B40, respectively. CONCLUSIONS: Screening of HLA class I antibodies in multiparous blood donors showed that HLA antisera of good quality could be obtained in about 1% of the donors in Korea.
Antibodies ; Antibody Specificity ; Blood Donors* ; Female ; Humans ; Immune Sera* ; Korea ; Mass Screening ; Sensitivity and Specificity ; Tissue Donors

BACKGROUND: The Rh system is the most important blood group after ABO in the transfusion field. Nearly half of irregular antibodies with specificity are related to Rh antigens in Korea. Formation of alloantibody for red blood cells is considered variable according to Rh phenotype of patients. We therefore studied the significance of Rh phenotype in Korean irregular antibody positive patients. METHODS: We performed retrospective reviews for the results of antibody identification tests performed from Jun. 2004 to Nov. 2013 in our university medical center. Rh phenotype, direct antiglobulin test, and antibody specificity were investigated. Rh phenotype was tested using RhD+ phenotype ID-card (DiaMed GmBH, Switzerland). RESULTS: A total of 504 patients were included. Of 504 patients, 495 (98.2%) were RhD positive. The proportion of Rh phenotype differed significantly between irregular antibody positive patients and known RhD positive Korean population in CDe phenotype (59.0% vs 39.4%, P<0.0001) and CcDEe phenotype (22.6% vs 38.4%, P<0.0001), respectively. The percentage of other Rh phenotype was not different in two groups. Formation of anti-E antibody in E negative patients was significantly higher than that of anti-C formation in C negative patients (P<0.0001). Sixteen patients showed antibodies with specificity for their own Rh system antigens. CONCLUSION: A significant disproportion of Rh phenotype was observed between irregular antibody positive patients and RhD positive Korean population. There would be a difference of immunogenicity among C/c and E/e antigens. E antigen matching might be considered first for patient required chronic transfusion if additional RBC matching would be implemented.
Academic Medical Centers ; Antibodies ; Antibody Specificity ; Coombs Test ; Erythrocytes ; Humans ; Korea ; Phenotype* ; Retrospective Studies ; Sensitivity and Specificity

Antibodies are immunoglobulins specifically introduced by immunity response of high animals, with the responsibility for recognising and cleaning out specific antigens. Antibody is not only a powerful weapon against pathogen invasion in the organism, but also a tool for specific molecular recognition used in basic scientific research. The diversity of antibody molecules resulted in the concept of antibody library; each individual animal is a natural antibody library. In the post-genome era, in order to fit various "omics", especially for proteomics requirement of high throughput technology, some gene engineering antibody libraries and antibody alternative libraries have been constructed based on phage display technology. Yet, more and more in vitro display systems such as ribosome display, mRNA display have been used for antibody library study, and that present more advantages than phage display. This mini review outlines the genesis, development and application prospect of antibody libraries according to the published reviews and research articles, and offers up to date development and application prospect of antibody library technology.
Animals ; Antibodies ; genetics ; physiology ; Antibody Diversity ; genetics ; Antibody Specificity ; Combinatorial Chemistry Techniques ; Gene Library ; Humans ; Peptide Library

Antibodies to high-incidence red blood cell antigens should be considered if panagglutination reactions are noted in all panel cells, and negative reactions to autologous red blood cells are detected on antibody screening and identification tests. In Korea, most of those antibodies are identified through international reference laboratories. To prevent a hemolytic transfusion reaction, antigen-negative red cells should be provided for those patients who have antibodies to red cell antigens. However, this is nearly impossible when the antibody has specificity to high-incidence red cell antigen. In those cases, transfusion of autologous blood, cryopreserved rare blood and the least incompatible blood components can be considered. In the case of surgery, acute normovolemic hemodilution or intraoperative blood salvage can also be considered. For the patients who have antibodies to high-incidence red cell antigens, it should be discussed to set up a national reference laboratory to quickly identify antibody specificities, and to consider establishing rare blood donor registry and frozen rare blood storage/supply system. This article reviews characteristics of antibodies to high-incidence antigens found in Koreans and also the transfusion experiences of those patients based on literature.
Antibodies ; Antibody Specificity ; Blood Donors ; Erythrocytes ; Hemodilution ; Humans ; Isoantibodies ; Korea ; Mass Screening ; Operative Blood Salvage ; Sensitivity and Specificity ; Transfusion Reaction

BACKGROUND: The gold standard for antinuclear antibody (ANA) screening is the indirect immunofluorescence (IIF) assay with human epithelial cells (HEp-2). However, a number of substantial disadvantages of manual IIF assays have highlighted the need for the automation and standardization of fluorescent ANA (FANA) testing. We evaluated the performance of EUROPattern Suite (Euroimmun AG, Germany), an automated FANA image analyzer, with regard to ANA detection and pattern recognition compared with conventional manual interpretation using the fluorescence microscopic IIF assay. METHODS: A total of 104 samples including 70 ANA-positive sera and 34 ANA-negative sera collected from September to October 2015 were included. The sensitivity, specificity, and pattern recognition function were evaluated to determine the performance of EUROPattern Suite compared with the manual IIF assay results. RESULTS: The sensitivity and specificity of EUROPattern Suite for ANA detection were 94.3% and 94.1%, respectively. The concordance rate between the two methods was 94.2%. For pattern recognition, 45.7% of the samples were assigned identical ANA patterns including simple and mixed. When major pattern matching was considered, 83.7% (41/49) and 95.2% (20/21) of the samples with simple and mixed patterns, respectively, showed concordant results between the two methods. CONCLUSIONS: EUROPattern Suite, an automated FANA image analyzer, provides a viable option for distinguishing between positive and negative results, although the ability to assign specific patterns is insufficient to replace manual microscopic interpretation. This automated system may increase efficiency in laboratories, in which a large number of samples need to be processed.
Antibodies, Antinuclear* ; Automation ; Epithelial Cells ; Fluorescence* ; Fluorescent Antibody Technique, Indirect ; Humans ; Mass Screening ; Sensitivity and Specificity

BACKGROUND: Since the introduction of anti-Rh immunoglobulin prophylaxis, the incidence of hemolytic disease of the newborn (HDN) due to anti-D has remarkably decreased while the number of HDN due to ABO antibodies or minor blood group antibodies remains same. In Caucasians, anti-c, anti-E and anti-K are antibodies most frequently implicated in HDN. But in Koreans, antigenic frequency of Rh or Kell blood group is very different from Caucasians, so it is expected that the frequency of antibodies causing HDN would also be very different. Because there has been no representative data on minor blood group antibodies causing HDN in Korea, we analyzed 79 antibodies associated with HDN. METHODS: From January 1989 to July 1998, we determined the antibody specificity causing HDN in 79 cases. The nature and in vitro characteristics of the antibodies were analyzed. RESULTS: Among 79 cases, ABO antibodies were responsible in 20 cases, and anti-D was responsible in 7 cases. In minor blood group incompatibility, anti-E+c (21 cases) and anti-E (18 cases) antibodies were the antibodies most commonly involved. In ABO incompatibility, Direct Coombs' test (DAT) on baby RBC was positive only in 65% (13/20 cases). In 13 cases, ABO antibodies were detected only in the eluate of baby RBC. In non-ABO incompatibility, 96.6% (57/59 cases) showed positive DAT. In cases associated with anti-E+c and anti-E, Rh subtypes of 20 mothers were all CCDee except one, and Rh subtypes of 12 babies were all CcDEe except one. CONCLUSION: In ABO-HDN, negative DAT was frequently found and the test on baby RBC eluate was an essential part for diagnosis. Among non-ABO incompatibility, Rh incompatibilities, including RhD, were responsible in 94.9% (56/59 cases). Among HDN due to minor blood group antibodies, in contrast to previous reports, we found that anti-E+c was the most common antibody involved in HDN.
Antibodies* ; Antibody Specificity ; Blood Group Incompatibility ; Coombs Test ; Diagnosis ; Humans ; Immunoglobulins ; Incidence ; Infant, Newborn* ; Korea ; Mothers

BACKGROUND: Patients with platelet refractoriness as a result of human leukocyte antigen (HLA) alloimmunization can be effectively managed by transfusion of HLA-matched platelets. In this study, we have retrospectively evaluated the effect of HLA-matched platelet transfusion using a hospital based donor pool of 450 HLA typed donors. METHODS: For 17 patients showing platelet refractoriness to random donor platelets [1 hr corrected count increment (CCI) <7, 500/microliter/m2; mean 1, 887/microliter/m2] and HLA alloimmunization, 78 single-donor apheresis platelets from 62 donors were transfused. HLA compatible donors were selected based on HLA match and patients' HLA antibody specificities. RESULTS: An average of 4.6 transfusions per patient were done and effective post-transfusion platelet increments were obtained with a mean 1 hr CCI of 17, 813/microliter/m2. In 76% (59/78) of the total transfusions, an effective platelet increment (1 hr CCI > or =7, 500/microliter/m2) was obtained. HLA crossmatch (NIH method) negative patients showed a significantly higher platelet increment compared with crossmatch positive patients (23, 877 vs 10, 823; P=0.000). Although better transfusion effect was obtained in higher grade HLA match of A-B2U by selection of HLA compatible donors according to patients' HLA antibody specificities, an effective platelet increment was obtained in lower grade matches as well. Platelets transfused < or =24 hours after collection showed a significantly higher platelet increment compared with those stored >24 hours (20, 325 vs 11, 417; P=0.029). CONCLUSIONS: Although many low grade matched donors were selected due to a relatively small size of HLA typed donor pool, effective platelet increments were obtained by selecting platelet donors on the basis of HLA antibody specificity.
Antibody Specificity ; Blood Component Removal ; Blood Platelets* ; Humans ; Leukocytes ; Platelet Transfusion* ; Retrospective Studies ; Tissue Donors