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: 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

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

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

Anti-Sda is of no clinical significance, because it rarely causes hemolytic transfusion reactions. Even when its presence is suspected during antibody screening test, further identification of the antibody is usually not performed. We experienced a case of anti-Sda in 73 yr-old male patient showing mixed field agglutination by microcolumn agglutination. Antibody specificity could not be identified by conventional antibody identification test, and it was proven to be anti-Sda by urine neutralization test. In spite of its little clinical significance, it may give incompatible crossmatching results reacting with Sda antigen, which occurs at a high frequency in general population. When incompatible crossmatch results arising from anti-Sda are suspected, the problem may be solved by using the urine-neutralized serum of in crossmatching test.
Agglutination ; Antibody Specificity ; Blood Group Incompatibility ; Humans ; Male ; Mass Screening ; Neutralization Tests

Although the confirmative diagnosis of typhoid fever is by culture of the causative organism, usually from blood, a serological test is still necessary to provide a more rapid method of diagnosis. The indirect fluorescent antibody test, using a Salmonella typhi Vi antigen and a FITC-conjugated rabbit anti-human polyvalent immunoglobulin, was evaluated for the diagnosis of typhoid fever. Serum specimens were collected from patients with febrile diseases on admission. Of the 32 patients with titers of 1:64 or more, 22 were confirmed to have typhoid fever by blood culture and 7 had fever of undetermined origin that was considered to be typhoid fever clinically. Three patients were diagnosed to have salmonellosis other than typhoid fever. Of the 121 patients with titers of 1:32 or less, 105 patients had non-typhoidal febrile disease, 15 patients had fever of undetermined origin, and one patient was confirmed to have typhoid fever by blood culture. When a Vi antibody titer of 1:64 or more was taken as serological evidence for the diagnosis of typhoid fever, the sensitivity and specificity were 95.7% and 97.2%, respectively. The incidence of positive test results following fever onset was 70.0% within 1 week of fever onset, 88.9% from 1 to 2 weeks, and 100% after 2 weeks. In conclusion, the Vi-indirect fluorescent antibody test(Vi-IFAT) can be employed as a useful serologic test in the diagnosis of typhoid fever.
Antigens, Bacterial/*analysis ; Fluorescent Antibody Technique/*standards ; Human ; Salmonella typhi/immunology ; Sensitivity and Specificity ; Typhoid Fever/*diagnosis

BACKGROUND: Antibody screening for donated blood is not yet being performed in Korea. Positive rate of irregular antibodies in Korean patients or blood donors has been thought to be much lower than that of foreign contries. We studied to know the actual frequency of irregular antibodies in blood donors with history of parturition using gel card, which was recently introduced in the field of blood banking and considered to be easy to standardize and sensitive to detect irregular antibodies. METHODS: 706 samples were collected from four blood centers in Seoul for 4 months. Antibody screening and identification were done by two kinds of Gel Card (DiaMed-ID corp, DiaMed, Murten, Switzerland) such as Nacl/Enzyme and LISS/Coombs' card. Adsorption- elution test was done in samples of which we could know the antibody specificity. RESULTS: Irregular antibodies were identified in 24 cases among 706 samples, therefore the overall frequency was 3.4% (95% CI: 3.4% +/- 1.3%). Only 4 cases, however, showed positive reaction in both enzyme and Coombs' phase, therefore frequency of clinically significant antibodies was 0.57% (95% CI: 0.57% +/- 0.55%). The identified irregular antibodies were anti-Lea (8 cases), Anti-Rh (3 cases) and Anti-P1 (1 case). Adsorption-elution test showed positive reaction only in 3 cases with anti-Rh antibodies. CONCLUSION: Considering that blood donors with history of parturition comprize just little proportion of total donors in Korea and frequency of irregular antibody is relatively lower than that of foreign countries in same group (0.57% vs 3.8%), it can be concluded that antibody screening be not urgent problem in Korean blood donation program.
Antibodies ; Antibody Specificity ; Blood Banks ; Blood Donors* ; Female ; Humans ; Korea ; Mass Screening ; Parturition* ; Seoul ; Tissue Donors