From The Scripps Research Institute, La Jolla, CA; Ben-Gurion University of the Negev, Beer-Sheva, Israel; and Amgen Inc, Thousand Oaks, CA.
Chronic immune thrombocytopenic purpura (ITP) is manifested by autoantibody-induced platelet destruction. Platelet turnover studies suggest that autoantibody may also affect platelet production. To evaluate this, we studied the effect of plasma from adult patients with chronic ITP on in vitro megakaryocyte production. CD34+ cells, obtained from healthy donors, were cultured in medium containing PEG-rHuMGDF and 10% plasma from either ITP patients or healthy subjects. Cultures containing plasma from 12 of 18 ITP patients showed a significant decrease (26%-95%) in megakaryocyte production when compared with control cultures. Positive ITP plasmas not only reduced the total number of megakaryocytes produced during the culture period but also inhibited megakaryocyte maturation, resulting in fewer 4N, 8N, and 16N cells. The role of antibody in this suppression is supported by 2 factors: (1) immunoglobulin G (IgG) from ITP patients inhibited megakaryocyte production when compared with control IgG; and (2) adsorption of autoantibody, using immobilized antigen, resulted in significantly less inhibition of megakaryocyte production when compared with unadsorbed plasma. These results show that plasma autoantibody from some adult patients with ITP inhibits in vitro megakaryocyte production, suggesting that a similar effect may occur in vivo.
Induction immunosuppression after heart transplantation: monoclonal vs. polyclonal antithymoglobulins. Is there a difference
Peristent Remodeling and Neointimal Suppression 2 Years After Polymer-Based, Paclitaxel-Eluting Stent Implantation
Dominant-Negative Suppression of HCN Channels Markedly Reduces the Native Pacemaker Current If and Undermines Spontaneous Beating of Neonatal Cardiomyocytes
Adenoviral Gene Transfer of Fortilin Attenuates Neointima Formation Through Suppression of Vascular Smooth Muscle Cell Proliferation and Migration
Simplification Therapy with Once-Daily Emtricitabine, Didanosine, and Efavirenz in HIV-1Infected Adults with Viral Suppression Receiving a Protease InhibitorBased Regimen: A Randomized Trial
Suppression and Modulation of Cellular and Humoral Immune Responses to Haemophilus influenzae Type B (Hib) Conjugate Vaccine in HibDiphtheria-Tetanus ToxoidsAcellular Pertussis Combination Vaccines: A
Immune Suppression Attenuates Hypertension and Renal Disease in the Dahl Salt-Sensitive Rat
Amelioration of Genetic Hypertension by Suppression of Renal G Protein–Coupled Receptor Kinase Type 4 Expression
Enhancement of Cardiac Function and Suppression of Heart Failure Progression By Inhibition of Protein Phosphatase 1
Preferential suppression of trisomy 8 compared with normal hematopoietic cell growth by autologous lymphocytes in patients with trisomy 8 myelodysplastic syndrome