Fcγ receptor expression on splenic macrophages in adult immune thrombocytopenia (original) (raw)
Related papers
Journal of autoimmunity, 2018
Innate lymphoid cells (ILCs) have been characterized as innate immune cells capable to modulate the immune response in the mucosae. Human ILCs have been rarely described in secondary lymphoid organs except in tonsils. Moreover, their function and phenotype in human secondary lymphoid organs during autoimmune diseases have never been studied. We took advantage of splenectomy as a treatment of immune thrombocytopenia (ITP) to describe and compare splenic ILC from 18 ITP patients to 11 controls. We first confirmed that ILC3 represented the most abundant ILC subset in human non-inflamed spleens, accounting for 90% of total ILC, and that they were mostly constituted of NKp44 cells. On the contrary, proportions of ILC1 and ILC2 in spleens were lower than in blood. Splenic IL-2- and IFN-γ-producing ILC1 were increased in ITP. While the frequencies of total splenic ILC3 were similar in the two groups, splenic GM-CSF-producing ILC3 were increased in ITP. This is the first description of huma...
BMC blood disorders, 2004
BACKGROUND: In view of clinical observations and laboratory results that support a central role of the spleen in idiopathic thrombocytopenic purpura (ITP) pathophysiology, we studied the effect of splenectomy on type-1 and type-2 cytokine gene expression in an adult ITP case, refractory to conservative treatment. CASE PRESENTATION: The patient was subjected to splenectomy 9 months after the diagnosis with complete response, attaining platelet counts over 150 x 106/L within 10 days after the operation. Two consecutive blood samples were obtained from the patient, 3 and 7 months after the splenectomy for the purposes of this study. A control group consisted of 11 healthy adults. Peripheral blood mononuclear cells were prepared from each blood sample and cultured in vitro for 8 h with the addition of the mitogens phorbol myristate acetate and ionomycin. Total cellular RNA extracted from 106 cells was submitted to semiquantitave reverse transcriptase-polymerase chain reaction (RT-PCR) f...
Blood, 2012
To understand more specific abnormalities of humoral autoimmunity, we studied 31 spleens from immune thrombocytopenia (ITP) patients and 36 control spleens. Detailed analysis identified at least 2 different splenic structures accommodating proliferating B cells, classic germinal centers (GCs), and proliferative lymphoid nodules (PLNs). PLNs were characterized by proliferating Ki67+ B cells close to follicular dendritic cells (FDCs) and lacked polarization into dark and light zones. As opposed to cells in GCs, proliferating B cells in PLN lacked expression of Bcl6. In both PLNs and GCs of ITP spleens, the density of T cells was significantly reduced. Both T follicular helper cells (TFH) and regulatory T cells were reduced within PLNs of ITP spleens suggesting a defect of tolerance related to a loss of T-cell control. Within PLNs of ITP, but not controls, abundant platelet glycoprotein (GP) IIb/IIIa autoantigens was found in IgM containing immune complexes tightly bound to FDCs and cl...
American Journal of Hematology, 2001
The acute platelet response to Intravenous Gammaglobulin (IVIG) has been reported to predict response to subsequent splenectomy of patients with ITP. The current study was undertaken to determine if the platelet response to IV anti-D (Winrho-SDF) predicts response to subsequent splenectomy. The 61 HIV-uninfected children and adults in this study had taken part in the pre-licensing studies of IV anti-D and were all those who not only had evaluable platelet responses to IV anti-D but also had undergone splenectomy and had information available describing its 1-year outcome. Results of treatment with IVIG were available in 38 of these 61 patients. Neither response to the initial infusion of IV anti-D, nor response to the initial or last IVIG, predicted the response in either children or adults to subsequent splenectomy. However, response to the last anti-D infusion in adults was strongly correlated (P = 0.003) to response to subsequent splenectomy as was hemolysis ≥2.0 gm/dl after IV anti-D (P = 0.03). There was no overall relationship between response to IV anti-D or IVIG, and response to subsequent splenectomy. However, a good platelet response in adults to the last IV anti-D and a hemoglobin decrease ≥2.0 gm/dl both appeared to predict response to subsequent splenectomy. Am. J. Hematol. 67:27-33, 2001.
The role of Fcγ receptors in murine autoimmune thrombocytopenia
Annals of Hematology, 2010
Immune thrombocytopenia (ITP) can become a life-threatening condition that requires immediate medical attention. The loss in platelet numbers during ITP can be induced by a variety of triggers. Anti-platelet antibodies of several isotypes and subclasses are a major cause for ITP and are a hallmark of many complex autoimmune diseases such as systemic lupus erythematosus. Mouse models have been important to understand the effector pathways involved in antibody-mediated platelet depletion. Therapeutic interventions based on these results have been proven successful in treating human ITP, thus validating the use of these model systems. One major problem that remains to be answered is which cell populations are crucial for platelet removal. Targeting these cells directly might be a novel therapeutic strategy and will also be important to understand the underlying biological mechanisms.
Blood, 2014
Antiplatelet-antibody-producing B cells play a key role in immune thrombocytopenia (ITP) pathogenesis; however, little is known about T-cell dysregulations that support B-cell differentiation. During the past decade, T follicular helper cells (TFHs) have been characterized as the main T-cell subset within secondary lymphoid organs that promotes B-cell differentiation leading to antibody class-switch recombination and secretion. Herein, we characterized TFHs within the spleen of 8 controls and 13 ITP patients. We show that human splenic TFHs are the main producers of interleukin (IL)-21, express CD40 ligand (CD154), and are located within the germinal center of secondary follicles. Compared with controls, splenic TFH frequency is higher in ITP patients and correlates with germinal center and plasma cell percentages that are also increased. In vitro, IL-21 stimulation combined with an anti-CD40 agonist antibody led to the differentiation of splenic B cells into plasma cells and to the...
Safety and efficacy of splenectomy in immune thrombocytopenia
American journal of blood research, 2021
BACKGROUND Immune Thrombocytopenia (ITP) is characterized by low platelet counts. Splenectomy has been in practice for the treatment of ITP since the early 20th century. We aimed to analyze the data of ITP patients from our hospital who underwent splenectomy and further present the long-term outcome and safety profile in these patients. METHOD This study was a single-center, registry based study conducted at a tertiary care hospital in Northern India. Patients aged 18 years or more, who underwent splenectomy after at least one line of therapy, were included in the study. The primary outcome was the overall response rate (ORR) at one month after splenectomy. Secondary outcomes were sustained response, relapse-free survival, factors affecting the ORR, and adverse events after splenectomy. RESULTS Forty-five patients of ITP were included in the study. Thirty-six patients underwent splenectomy in the first half (2001-2010), of the study period. The median age of the patients was 38 (19-...
American Journal of Hematology, 2001
This study was conducted to verify whether the response to high-dose intravenous immune globulin (IVIG) was related to the effect of splenectomy in chronic idiopathic thrombocytopenic purpura (ITP) patients. A total of 79 patients over 16 years of age were enrolled in this study. The response to the treatment was classified on the basis of the platelet count as no response (NR, <50 × 10 9 /l), incomplete response (IR, (50-150) × 10 9 /l), and complete response (CR, >150 × 10 9 /l). The response was evaluated after the infusion of high-dose IVIG, within 2 weeks after splenectomy (immediate response), and during a follow-up period of more than 6 months after splenectomy (sustained response), respectively. 58 patients (73.4%) showed responses (CR or IR) to high-dose IVIG. After splenectomy, immediate responses were observed in 73 patients (92%). The response to highdose IVIG had no relationship with the immediate response to splenectomy (P = 0.333). A follow-up evaluation was possible with 58 patients; 6 patients with NR in immediate responses did not show any response during the follow-up period, and 17 patients relapsed within 6 months after immediate responses, so 35 patients (60.3%) had sustained responses. Responders to IVIG had significantly higher sustained response rates to splenectomy than non-responders (62% vs. 38%, P = 0.001). These results indicate that the response to high-dose IVIG could be a valuable factor predicting the sustained response to splenectomy in chronic ITP patients. Am.