OBJECTIVETo detect platelet anti-HPA-1a and -1b antibodies using recombinant GPIIIa fragments coupled to Luminex beads.

METHODSThe sensitivity of 2 techniques, monoclonal antibody specific immobilization of platelet antigen (MAIPA) and Luminex bead assay, was compared using 12 twofold-serial dilutions (from neat to 1 in 2048) of an anti-HPA-1a WHO international standard. The specificity of Luminex assay to identify anti-HPA-1a and -1b antibodies was assessed using 8 negative or positive controls and 36 blinded samples provided by WHO Platelet Workshop.

RESULTSThe sensitivity of MAIPA and Luminex bead assay to detect anti-HPA-1a was dilution 1/64 (i.e. 1.56 IU/ml) and far more than dilution 1/2048 (i.e. 0.049 IU/mL), respectively. The Luminex bead assay could specifically identify negative and positive controls of anti-HPA-1a and -1b. All results of 36 blinded samples by Luminex assay were accordant to reference results except one sample which contained high concentration antithetical antibody and resulted in false positive of anti-HPA-1b. Cross-reactivity was also not observed with the samples containing HLA, ABO or other platelet antibodies.

CONCLUSIONThe Luminex beads coupled with recombinant GPIIIa fragments can be used to detect HPA-1 system antibodies with sufficient sensitivity and specificity, that is suitable for the detection of platelet alloantibodies in clinical alloimmune thrombocytopenia.

Antibodies, Monoclonal ; Antigens, Human Platelet ; immunology ; Blood Platelets ; Humans ; Integrin beta3 ; chemistry ; Isoantibodies ; blood ; Purpura, Thrombocytopenic, Idiopathic ; diagnosis ; Recombinant Proteins ; chemistry ; Sensitivity and Specificity

Intravenous immunoglobulin (IVIG) and/or plasmapheresis (PP) are effective in preventing antibody-mediated rejection (AMR) of kidney allografts, but AMR is still a problem. This study reports our experience in living donor renal transplantation in highly sensitized patients. Ten patients with positive crossmatch tests or high levels of panel-reactive antibody (PRA) were included. Eight patients were desensitized with pretransplant PP and low dose IVIG, and two were additionally treated with rituximab. Allograft function, number of acute rejection (AR) episodes, protocol biopsy findings, and the presence of donor-specific antibody (DSA) were evaluated. With PP/IVIG, six out of eight patients showed good graft function without AR episodes. Protocol biopsies revealed no evidence of tissue injury or C4d deposits. Of two patients with AR, one was successfully treated with PP/IVIG, but the other lost graft function due to de novo production of DSA. Thereafter, rituximab was added to PP/IVIG in two cases. Rituximab gradually decreased PRA levels and the percentage of peripheral CD20+ cells. DSA was undetectable and protocol biopsy showed no C4d deposits. The graft function was stable and there were no AR episodes. Conclusively, desensitization using PP/IVIG with or without rituximab increases the likelihood of successful living donor renal transplantation in sensitized recipients.
Adult ; Antibodies, Monoclonal/therapeutic use ; Antigens, CD20/biosynthesis ; Female ; Humans ; Immunoglobulins/metabolism ; Immunophenotyping ; Immunosuppressive Agents/therapeutic use ; Isoantibodies/chemistry ; Kidney Failure, Chronic/therapy ; Kidney Transplantation/*methods ; Lymphocytes/metabolism ; Male ; Middle Aged ; Retrospective Studies

BACKGROUND: The aim of this study was to investigate the frequency of autoantibodies with mimicking specificity by using the dilution technique, to assess the usefulness of the combination of the dilution technique and red blood cell (RBC) phenotyping, and to establish a pre-transfusion testing algorithm in patients with warm autoantibodies. METHODS: Serum samples from 71 patients with warm autoantibodies were tested using the dilution technique. Among them, 25 samples were adsorbed with allogeneic ZZAP (a combination of dithiothreitol and enzyme) or polyethylene glycol (PEG) and their RBC phenotypes were determined. Thirty-nine patients were transfused with our pre-transfusion testing algorithm using a combination of dilution technique and RBC phenotyping. RESULTS: Autoantibodies with mimicking specificity were detected by the dilution technique in 26.8% (19/71) of the patients and most of them were directed against Rh system antigens. The agreement of the results obtained with the dilution technique in combination with RBC phenotyping and those from ZZAP or PEG adsorption was 100% (18/18) in patients who have autoantibodies with mimicking specificity and/or alloantibodies. No clinical symptoms indicating severe acute or delayed hemolytic transfusion reactions were reported in the 39 patients transfused with our pre-transfusion testing algorithm. CONCLUSIONS: Autoantibodies with mimicking specificity detected by the dilution technique in patients with warm autoantibodies are relatively frequent, can be discriminated from alloantibodies by employing a combination of dilution technique and RBC phenotyping, and might not appear to cause severe acute or delayed hemolytic transfusion reactions.
Adolescent ; Adsorption ; Adult ; Aged ; Aged, 80 and over ; Algorithms ; Antibody Specificity ; Autoantibodies/*blood ; Child ; Erythrocytes/cytology/metabolism ; Female ; Humans ; *Indicator Dilution Techniques ; Isoantibodies/blood ; Male ; Middle Aged ; Phenotype ; Polyethylene Glycols/chemistry ; Temperature ; Young Adult

BACKGROUND: Duffy (FY) blood group genotyping is important in transfusion medicine because Duffy alloantibodies are associated with delayed hemolytic transfusion reactions and hemolytic disease of the fetus and newborn. In this study, FY allele frequencies in Thai blood donors were determined by in-house PCR with sequence-specific primers (PCR-SSP), and the probability of obtaining compatible blood for alloimmunized patients was assessed. METHODS: Five hundred blood samples from Thai blood donors of the National Blood Centre, Thai Red Cross Society, were included. Only 200 samples were tested with anti-Fy(a) and anti-Fy(b) using the gel technique. All 500 samples and four samples from a Guinea family with the Fy(a-b-) phenotype were genotyped by using PCR-SSP. Additionally, the probability of obtaining antigen-negative red blood cells (RBCs) for alloimmunized patients was calculated according to the estimated FY allele frequencies. RESULTS: The FY phenotyping and genotyping results were in 100% concordance. The allele frequencies of FY*A and FY*B in 500 central Thais were 0.962 (962/1,000) and 0.038 (38/1,000), respectively. Although the Fy(a-b-) phenotype was not observed in this study, FY*B(ES)/FY*B(ES) was identified by PCR-SSP in the Guinea family and was confirmed by DNA sequencing. CONCLUSIONS: Our results confirm the high frequency of the FY*A allele in the Thai population, similar to that of Asian populations. At least 500 Thai blood donors are needed to obtain two units of antigen-negative RBCs for the Fy(a-b+) phenotype.
Adult ; Alleles ; Asian Continental Ancestry Group/genetics ; Base Sequence ; Blood Donors ; DNA/chemistry/genetics/metabolism ; Duffy Blood-Group System/*genetics/immunology ; Female ; Gene Frequency ; Genotype ; Humans ; Isoantibodies/blood/immunology ; Male ; Middle Aged ; Phenotype ; Polymerase Chain Reaction ; Receptors, Cell Surface/genetics/*immunology ; Sequence Analysis, DNA ; Thailand ; Young Adult

This study is to investigate the effects of paeoniflorin (Pae) on the levels of related serum antibodies and cAMP of splenocytes in rats with adjuvant arthritis. Complete Freund's adjuvant was used to induce AA in rats. The level of circulating immune complexes in serum was determined by PEG6000 assay, and the levels of anti-C II antibody and anti-TB antibody in serum were measured by enzyme-linked immunosorbent assay (ELISA), the level of cAMP in splenocytes was measured by radioimmunoassay, separately. Pae (25, 50, and 100 mg x kg(-1)) and GTW (40 mg x kg(-1)) were given by intragastric administration for 7 days from the 17th day after immunization. Pae (50 and 100 mg x kg(-1)) reduced the levels of circulating immune complexes, anti-C II antibody and anti-TB antibody in serum in rats with adjuvant arthritis. The inhibition ratios of Pae groups to AA model group were dosage-dependent; Pae (12.5, 62.5, and 312.5 mg x L(-1)) decreased the elevated levels of cAMP in splenocytes in vitro. Pae (ig) decreased the levels of related serum antibodies and elevated the level of cAMP in rats with adjuvant arthritis.
Animals ; Antibodies, Bacterial ; blood ; Antigen-Antibody Complex ; blood ; Arthritis, Experimental ; chemically induced ; immunology ; Benzoates ; isolation & purification ; pharmacology ; Bridged-Ring Compounds ; isolation & purification ; pharmacology ; Cyclic AMP ; metabolism ; Dose-Response Relationship, Drug ; Freund's Adjuvant ; Glucosides ; isolation & purification ; pharmacology ; Isoantibodies ; blood ; Monoterpenes ; Mycobacterium tuberculosis ; immunology ; Paeonia ; chemistry ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Spleen ; cytology ; metabolism

OBJECTIVETo examine the effect of multi-glycoside of Tripterygium wilfordii Hook. f. (GTW) on proteinuria and expression of slit diaphragm-associated molecules such as nephrin and podocin in glomerulonephritis induced by anti-Thy1.1 antibody (anti-Thy1 . 1 GN).

METHODSAnti-Thy1.1 GN was induced in rats by a single intravenous injection with 500 microg of anti-Thy1.1 mAb 1-22-3. Fourteen rats were randomly divided into 2 groups, the GTW-treated group and vehicle treated group, and sacrificed on day 14 in Experiment 1 or on day 7 in Experiment 2 after induction of Anti-Thy1.1 GN. Daily oral administration of GTW and vehicle as a control was started from 3 days before injection or at the same time of injection to the day of sacrifice in Experiment 1 or 2. Proteinuria was determined during 14 days in Experiment 1 or during 7 days in Experiment 2. From kidneys taken at sacrifice, glomerular morphological changes, glomerular macrophage infiltration, glomerular expression of nephrin and podocin, and its mRNA expression in renal tissue were examined.

RESULTSIn Experiment 1, proteinuria and mesangial matrix expansion were significantly attenuated by GTW treatment. No difference in staining intensity of nephrin and podocin in glomeruli was observed between GTW treated group and vehicle treated group on day 14. In Experiment 2, GTW treatment significantly ameliorated proteinuria, mesangial injury and activated macrophage infiltration in glomerulus. In addition, it significantly increased the expression of nephrin and podocin and its mRNA expression in glomeruli on day 7.

CONCLUSIONIn anti-Thy1.1 GN, the reduced expression of nephrin and podocin may contribute to the development of mesangial injury and proteinuria. The findings suggest that GTW ameliorates not only proteinuria but also mesangial lesions in anti-Thy1 . 1 GN most likely by increasing the expression of nephrin and podocin.

Animals ; Female ; Fluorescent Antibody Technique ; Glomerulonephritis, Membranoproliferative ; drug therapy ; immunology ; Glycosides ; therapeutic use ; Intracellular Signaling Peptides and Proteins ; genetics ; Isoantibodies ; immunology ; Membrane Proteins ; biosynthesis ; genetics ; Phytotherapy ; Podocytes ; drug effects ; metabolism ; pathology ; Proteinuria ; drug therapy ; Rats ; Reverse Transcriptase Polymerase Chain Reaction ; Thy-1 Antigens ; immunology ; Tripterygium ; chemistry