PAICA: A Method for Characterizing Platelet-Associated Antibodies - Its Application to the Study of Idiopathic Thrombocytopenic Purpura and to the Detection of Platelet-bound c7E3

1996 ◽  
Vol 76 (06) ◽  
pp. 1020-1029 ◽  
Author(s):  
Laurent Macchi ◽  
Gisèle Clofent-Sanchez ◽  
Gérald Marit ◽  
Claude Bihour ◽  
Catherine Durrieu-Jais ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Flow Cytometry ◽  
Idiopathic Thrombocytopenic Purpura ◽  
Antithrombotic Therapy ◽  
Membrane Glycoproteins ◽  
Serum Antibodies ◽  
Platelet Destruction ◽  
Thrombocytopenic Purpura ◽  
Capture Assay ◽  
Specific Membrane

SummaryIn idiopathic thrombocytopenic purpura (ITP), autoantibodies reacting with antigens on the platelet membrane bring about accelerated platelet destruction. We now report PAICA (“Platelet-Associated IgG Characterization Assay”), a method for detecting autoantibodies bound to specific membrane glycoproteins in total platelet lysates. This monoclonal antibody (MAb) capture assay takes into account the fact that antibodies on circulating platelets may be translocated to internal pools as well as being on the surface. A total of twenty ITP patients were examined by PAICA, and the results compared with those obtained by measuring (i) serum antibodies bound to paraformaldehyde-fixed control platelets by ELISA, (ii) IgG bound to the surface of the patient’s own platelets by flow cytometry (PSIgG), (iii) total platelet-associated IgG (PAIgG) by ELISA and (iv) serum antibodies reacting with control platelets by MAIPA (“Monoclonal Antibody-specific Immobilization of Platelet Antigens”). Of twelve patients with elevated PAIgG, nine had increased PSIgG yet eleven reacted positively in PAICA. Of these, eight possessed antibodies directed against GP Ilb-IIIa, two against GP Ib-IX and one patient possessed antibodies directed against GP Ilb-IIIa and GP Ia-IIa respectively. Only seven of the patients possessed serum antibodies detectable by MAIPA. PAICA was also able to detect platelet-associated c7E3 (the chimeric form of Fab fragments of the MAb 7E3) following its infusion during antithrombotic therapy, when it proved more sensitive over a seven-day period than a MAIPA assay adapted for assessing surface-bound antibody. We propose that PAICA provides added sensitivity to the detection of platelet-associated antibodies in immune thrombocytopenias or following therapy with humanized MAbs.

scholarly journals Spectrum of Ig classes, specificities, and titers of serum antiglycoproteins in chronic idiopathic thrombocytopenic purpura

Blood ◽  
1994 ◽  
Vol 83 (4) ◽  
pp. 1024-1032 ◽  
Author(s):  
R He ◽  
DM Reid ◽  
CE Jones ◽  
NR Shulman
Keyword(s):  
Idiopathic Thrombocytopenic Purpura ◽  
Cytoplasmic Domain ◽  
Platelet Glycoprotein ◽  
Chronic Idiopathic Thrombocytopenic Purpura ◽  
Platelet Destruction ◽  
Thrombocytopenic Purpura ◽  
Secondary Phenomenon ◽  
Almost All ◽  
Posttransfusion Purpura ◽  
Detectable Serum

Abstract The characteristic decreased recovery and survival of transfused platelets in nonalloimmunized patients with idiopathic thrombocytopenic purpura (ITP) suggest that plasma antiplatelet autoantibodies (autoAbs) are present in almost all cases. Studies emphasizing reactions of IgG autoAbs with platelet glycoprotein (GP) IIb/IIIa indicate that less than 50% of ITP patients have detectable serum Abs, and that many of these Abs may not be pathogenic because they are directed against epitopes in the cytoplasmic domain of GPIIIa (Fujisawa et al, Blood 77:2207, 1991 and 79:1441, 1992). We evaluated the contribution of Ig classes other than IgG to the overall incidence of serum Abs in 47 patients with chronic ITP and the frequency of reactions with GPs IIb/IIIa, Ib/IX, IV, and Ia/IIa. Abs were further characterized by their reactions with cytosolic or exosolic GP epitopes and their titers and apparent affinities. Using immunobead techniques we found (1) anti- GPs in 85% of sera; (2) IgA and IgG Abs each in 68%, together in 51%; (3) IgM agglutinins in 15%, always with another Ab class; (4) GP Ib/IX, IIb/IIIa, IV, and Ia/IIa targets in 83%, 81%, 38%, and 28% of cases, respectively; (5) 93% of positive sera reactive with more than one GP; but GP IV or Ia/IIa never the sole target; (6) Abs against cytosolic epitopes on one or more of GPs IIIa, Ib alpha, and IIb beta in 66% of sera, always accompanied by Abs against exosolic epitopes of the same or a different GP; (7) autoAbs against cytosolic GP epitopes in 38% of 16 patients recovered from posttransfusion purpura and drug purpura; and (8) evidence that serum ITP Abs, often high-titered, saturate platelets less than alloAbs against the same GPs. Whereas Abs against external GP epitopes are a distinctive marker for ITP in 80% of patients, Abs against internal GP epitopes are likely a secondary phenomenon of platelet destruction and not pathogenic. Anti-GPs against exosolic epitopes were also found in eluates of patients platelets', suggesting that they have pathogenic significance.

scholarly journals Detection of various platelet-associated immunoglobulins by flow cytometry in idiopathic thrombocytopenic purpura

2005 ◽  
Vol 68B (1) ◽  
pp. 37-42 ◽  
Author(s):  
Takuya Nishioka ◽  
Takahisa Yamane ◽  
Takayuki Takubo ◽  
Kensuke Ohta ◽  
Keunsik Park ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Idiopathic Thrombocytopenic Purpura ◽  
Thrombocytopenic Purpura

scholarly journals Chronic Refractory Idiopathic Thrombocytopenic Purpura (ITP) and Anti-CD20 Monoclonal Antibody: A Case Report

2006 ◽  
Vol 12 (4) ◽  
pp. 489-492 ◽  
Author(s):  
S. Z. Latifzadeh ◽  
V. Entezari
Keyword(s):  
Monoclonal Antibody ◽  
Platelet Count ◽  
Idiopathic Thrombocytopenic Purpura ◽  
Specific Antigen ◽  
Genetically Engineered ◽  
Low Grade ◽  
Treatment Schedule ◽  
Thrombocytopenic Purpura ◽  
Anti Cd20 ◽  
Refractory Itp

Idiopathic thrombocytopenic purpura (ITP) is an immune-mediated disorder characterized by accelerated and premature destruction of platelets by reticuloendothelial system. CD20, a trans-membrane B-cell-specific antigen, is a potential target for treatment of certain malignant and nonmalignant plasma cell disorders including refractory ITP. Rituximab is a genetically engineered human anti-CD20 monoclonal antibody, which is approved for the treatment of low-grade non-Hodgkin’s lymphoma. Recent clinical reports suggest that rituximab may be useful in treating certain patients with chronic refractory ITP. A 59-year-old woman with refractory ITP was placed on rituximab (four weekly doses of 375 mg/m2) and her condition and platelet count were observed for 18 months. There was a gradual increase in platelet count and she was symptom free in this period and no side effects of the drug were reported. Anti-CD20 antibodies are likely to be used in the treatment of refractory ITP cases, but further studies about treatment schedule and criteria for patient selection should be done.

Profiles of Th1, Th2, Th17 and Treg Cells in Patients with Chronic Idiopathic Thrombocytopenic Purpura.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3404-3404
Author(s):  
Rong-Fu Zhou ◽  
Jian Ou-yang ◽  
Da-Yu Chang ◽  
Jing-Yan Xu ◽  
Bing Chen ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Idiopathic Thrombocytopenic Purpura ◽  
Peripheral Blood ◽  
Th17 Cells ◽  
Treg Cells ◽  
Chronic Idiopathic Thrombocytopenic Purpura ◽  
Active Stage ◽  
Thrombocytopenic Purpura ◽  
Chronic Itp ◽  
Ifn Γ

Abstract Objective: To explore the profiles of Th1,Th2, Th17 and Treg cells in patients with chronic idiopathic thrombocytopenic purpura. Methods: Samples of peripheral blood were collected from 30 chronic ITP patients ( 9 males and 21 females), aged 41, 21 being in active stage, and 9 in remission stage, and 9 healthy persons in control (3 males and 6 females), aged 36. Peripheral blood was cultured, and activated with PMA/ionomycin when Th1, Th2 and Th17 cells were detected. Flow cytometry was used to measure the intracellular cytokines interferon (IFN)-γ, interleukin (IL)-4 and interleukin (IL)-17 so as to identify the Th1 cells (CD3+ CD8− IFN-γ+ IL-4− cells), Th2 cells (CD3+ CD8− IFN-γ − IL-4+ cells) and IL-17 cells (CD3+ CD8− IL-17+ cells); Treg cells were identified to CD4+ CD25+ Foxp3+ cells and uncultured peripheral blood was used to measured the CD4+ CD25+ Foxp3+ cells by flow cytometry. The ratios of Th1/Th2 were calculated. Results: The Th1/Th2 ratio for patients in active stage was 15.04±9.67, significantly higher than those for patients in remission stage (7.17±5.38, P <0.05) and in control (8.47±3.78, P <0.05); the percentage of Treg cells of the patients in active stage was 0.89±0.58%, significantly decreased than those of patients in remission stage (6.41±1.86%, P <0.001) and in control (6.06±0.85%, P <0.001); the percentage of Th17 cells was 1.94±0.77% for patients in active stage, 2.16±0.52% for patients in remission stage and 1.82±0.58% for patients in control, respectively, and there was no statistic significance between them. Conclusion: Chronic ITP is a Th1 predominant disease; decreased number and function of Treg cells might be one of mechanisms that cause immune regulation dysfunction in chronic ITP; Th17 cells might not play a role in the development of chronic ITP.

Clonal B-cell populations in patients with idiopathic thrombocytopenic purpura

Blood ◽  
1990 ◽  
Vol 76 (11) ◽  
pp. 2321-2326 ◽  
Author(s):  
D van der Harst ◽  
D de Jong ◽  
J Limpens ◽  
PM Kluin ◽  
Y Rozier ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
B Cells ◽  
Autoimmune Diseases ◽  
B Cell ◽  
Malignant Lymphoma ◽  
Idiopathic Thrombocytopenic Purpura ◽  
Clinical Manifestations ◽  
Cell Populations ◽  
Dna Rearrangement ◽  
Thrombocytopenic Purpura

Idiopathic thrombocytopenic purpura (ITP) may be associated with other autoimmune diseases and the development of lymphoproliferative malignancies. In Sjogren's disease, Graves' disease, and essential mixed cryoglobulinemia, which are also associated with the development of B-cell neoplasia, clonal B-cell expansions have been detected. Eleven patients with ITP were investigated for the presence of a clonal excess (CE) using kappa-lambda flow cytometry and DNA analysis for rearrangement of immunoglobulin heavy and light chain genes in blood and/or spleen lymphocytes. In 10 of 11 patients, clonal B-cell populations were found by one or both tests. In three of these patients, oligoclonal B-cell populations were suggested by the combined findings. In all four patients with a small paraproteinemia, the isotype was confirmed by either flow cytometry or DNA rearrangement analysis. Our data suggest that the oligoclonal expansions are not restricted to CD5+ B cells, as in the majority of patients this subset was below the detection level of flow cytometry or DNA rearrangement analysis. None of the patients developed clinical manifestations of malignant lymphoma during a follow-up period of 10 to 44 months after sampling. We conclude that clonal excess populations of B cells are not a unique feature of malignant lymphoma, but may occur in autoimmune diseases, suggesting a benign (oligo)clonal B-cell proliferation.

Rituximab chimeric anti-CD20 monoclonal antibody treatment for adults with chronic idiopathic thrombocytopenic purpura

Blood ◽  
2001 ◽  
Vol 98 (4) ◽  
pp. 952-957 ◽  
Author(s):  
Roberto Stasi ◽  
Adalberto Pagano ◽  
Elisa Stipa ◽  
Sergio Amadori
Keyword(s):  
Monoclonal Antibody ◽  
Platelet Count ◽  
Side Effects ◽  
Partial Response ◽  
Idiopathic Thrombocytopenic Purpura ◽  
Chronic Idiopathic Thrombocytopenic Purpura ◽  
Antibody Treatment ◽  
Minor Response ◽  
Thrombocytopenic Purpura ◽  
Chronic Itp

The role of rituximab, a chimeric monoclonal antibody directed against the CD20 antigen, in the treatment of patients with chronic idiopathic thrombocytopenic purpura (ITP) has not been determined. The effectiveness and side effects of this therapeutic modality were investigated in a cohort of 25 individuals with chronic ITP. All patients had ITP that had been resistant to between 2 and 5 different therapeutic regimens, including 8 patients who had already failed splenectomy. Patients were scheduled to receive intravenous rituximab at the dose of 375 mg/m2 once weekly for 4 weeks. Rituximab infusion-related side effects were observed in 18 patients, but were of modest intensity and did not require discontinuation of treatment. A complete response (platelet count greater than 100 × 109/L) was observed in 5 cases, a partial response (platelet count between 50 and 100 × 109/L) in 5 cases, and a minor response (platelet count below 50 × 109/L, with no need for continued treatment) in 3 cases, with an overall response rate of 52%. In 7 cases, responses were sustained (6 months or longer). In 2 patients with relapsed disease, repeat challenge with rituximab induced a new response. In patients with a complete or partial response, a significant rise in platelet concentrations was observed early during the course of treatment, usually 1 week after the first rituximab infusion. No clinical or laboratory parameter was found to predict treatment outcome, although there was a suggestion that women and younger patients have a better chance of response. In conclusion, rituximab therapy has a limited but valuable effect in patients with chronic ITP. In view of its mild toxicity and the lack of effective alternative treatments, its use in the setting of chronic refractory ITP is warranted.

Sign in / Sign up

Export Citation Format

Share Document