1
|
Delshad M, Davoodi-Moghaddam Z, Pourbagheri-Sigaroodi A, Faranoush M, Abolghasemi H, Bashash D. Translating mechanisms into therapeutic strategies for immune thrombocytopenia (ITP): Lessons from clinical trials. Thromb Res 2024; 235:125-147. [PMID: 38335568 DOI: 10.1016/j.thromres.2024.02.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 01/30/2024] [Accepted: 02/05/2024] [Indexed: 02/12/2024]
Abstract
Immune thrombocytopenia (ITP) is an autoimmune disorder that causes a significant reduction in peripheral blood platelet count. Fortunately, due to an increased understanding of ITP, there have been significant improvements in the diagnosis and treatment of these patients. Over the past decade, there have been a variety of proven therapeutic options available for ITP patients, including intravenous immunoglobulins (IVIG), Rituximab, corticosteroids, and thrombopoietin receptor agonists (TPO-RAs). Although the effectiveness of current therapies in treating more than two-thirds of patients, still some patients do not respond well to conventional therapies or fail to achieve long-term remission. Recently, a significant advancement has been made in identifying various mechanisms involved in the pathogenesis of ITP, leading to the development of novel treatments targeting these pathways. It seems that new agents that target plasma cells, Bruton tyrosine kinase, FcRn, platelet desialylation, splenic tyrosine kinase, and classical complement pathways are opening new ways to treat ITP. In this study, we reviewed the pathophysiology of ITP and summarized updates in this population's management and treatment options. We also took a closer look at the 315 ongoing trials to investigate their progress status and compare the effectiveness of interventions. May our comprehensive view of ongoing clinical trials serve as a guiding beacon, illuminating the path towards future trials of different drugs in the treatment of ITP patients.
Collapse
Affiliation(s)
- Mahda Delshad
- Department of Hematology and Blood Banking, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Department of Laboratory Sciences, School of Allied Medical Sciences, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Zeinab Davoodi-Moghaddam
- Department of Hematology and Blood Banking, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Atieh Pourbagheri-Sigaroodi
- Department of Hematology and Blood Banking, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Faranoush
- Pediatric Growth and Development Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Hassan Abolghasemi
- Pediatric Congenital Hematologic Disorders Research Center, Research Institute for Children's Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Davood Bashash
- Department of Hematology and Blood Banking, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
| |
Collapse
|
2
|
Novel Therapies to Address Unmet Needs in ITP. Pharmaceuticals (Basel) 2022; 15:ph15070779. [PMID: 35890078 PMCID: PMC9318546 DOI: 10.3390/ph15070779] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 06/16/2022] [Accepted: 06/20/2022] [Indexed: 02/04/2023] Open
Abstract
Primary immune thrombocytopenia (ITP) is an autoimmune disorder that causes low platelet counts and subsequent bleeding risk. Although current corticosteroid-based ITP therapies are able to improve platelet counts, up to 70% of subjects with an ITP diagnosis do not achieve a sustained clinical response in the absence of treatment, thus requiring a second-line therapy option as well as additional care to prevent bleeding. Less than 40% of patients treated with thrombopoietin analogs, 60% of those treated with splenectomy, and 20% or fewer of those treated with rituximab or fostamatinib reach sustained remission in the absence of treatment. Therefore, optimizing therapeutic options for ITP management is mandatory. The pathophysiology of ITP is complex and involves several mechanisms that are apparently unrelated. These include the clearance of autoantibody-coated platelets by splenic macrophages or by the complement system, hepatic desialylated platelet destruction, and the inhibition of platelet production from megakaryocytes. The number of pathways involved may challenge treatment, but, at the same time, offer the possibility of unveiling a variety of new targets as the knowledge of the involved mechanisms progresses. The aim of this work, after revising the limitations of the current treatments, is to perform a thorough review of the mechanisms of action, pharmacokinetics/pharmacodynamics, efficacy, safety, and development stage of the novel ITP therapies under investigation. Hopefully, several of the options included herein may allow us to personalize ITP management according to the needs of each patient in the near future.
Collapse
|
3
|
Kuter DJ. Novel therapies for immune thrombocytopenia. Br J Haematol 2021; 196:1311-1328. [PMID: 34611885 DOI: 10.1111/bjh.17872] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Revised: 09/17/2021] [Accepted: 09/19/2021] [Indexed: 01/02/2023]
Abstract
Current therapies for immune thrombocytopenia (ITP) are successful in providing a haemostatic platelet count in over two-thirds of patients. Still, some patients have an inadequate response and there is a need for other therapies. A number of novel therapies for ITP are currently being developed based upon the current pathophysiology of ITP. Many therapies are targetted at reducing platelet destruction by decreasing anti-platelet antibody production by immunosuppression with monoclonal antibodies targetted against CD40, CD38 and the immunoproteasome or physically reducing the anti-platelet antibody concentration by inhibition of the neonatal Fc receptor. Others target the phagocytic system by inhibiting FcγR function with staphylococcal protein A, hypersialylated IgG, polymeric Fc fragments, or Bruton kinase. With a recognition that platelet destruction is also mediated by complement, inhibitors of C1s are also being tested. Inhibition of platelet desialylation may also play a role. Other novel therapies promote platelet production with new oral thrombopoietin receptor agonists or the use of low-level laser light to improve mitochondrial activity and prevent megakaryocyte apoptosis. This review will focus on these novel mechanisms for treating ITP and assess the status of treatments currently under development. Successful new treatments for ITP might also provide a pathway to treat other autoimmune disorders.
Collapse
Affiliation(s)
- David J Kuter
- Hematology Division, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| |
Collapse
|
4
|
Liu X, Cao W, Li T. High-Dose Intravenous Immunoglobulins in the Treatment of Severe Acute Viral Pneumonia: The Known Mechanisms and Clinical Effects. Front Immunol 2020; 11:1660. [PMID: 32760407 PMCID: PMC7372093 DOI: 10.3389/fimmu.2020.01660] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 06/22/2020] [Indexed: 12/30/2022] Open
Abstract
The current outbreak of viral pneumonia, caused by novel coronavirus SARS-CoV-2, is the focus of worldwide attention. The WHO declared the COVID-19 outbreak a pandemic event on Mar 12, 2020, and the number of confirmed cases is still on the rise worldwide. While most infected individuals only experience mild symptoms or may even be asymptomatic, some patients rapidly progress to severe acute respiratory failure with substantial mortality, making it imperative to develop an efficient treatment for severe SARS-CoV-2 pneumonia alongside supportive care. So far, the optimal treatment strategy for severe COVID-19 remains unknown. Intravenous immunoglobulin (IVIg) is a blood product pooled from healthy donors with high concentrations of immunoglobulin G (IgG) and has been used in patients with autoimmune and inflammatory diseases for more than 30 years. In this review, we aim to highlight the known mechanisms of immunomodulatory effects of high-dose IVIg therapy, the immunopathological hypothesis of viral pneumonia, and the clinical evidence of IVIg therapy in viral pneumonia. We then make cautious therapeutic inferences about high-dose IVIg therapy in treating severe COVID-19. These inferences may provide relevant and useful insights in order to aid treatment for COVID-19.
Collapse
Affiliation(s)
- Xiaosheng Liu
- Tsinghua-Peking Center for Life Sciences, School of Medicine, Tsinghua University, Beijing, China
| | - Wei Cao
- Department of Infectious Diseases, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China
| | - Taisheng Li
- Tsinghua-Peking Center for Life Sciences, School of Medicine, Tsinghua University, Beijing, China
- Department of Infectious Diseases, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China
| |
Collapse
|
5
|
SMITH N, MRCP MB, CHAKRAVERTY R, BOUGHTON B. The successful treatment of idiopathic thrombocytopenic purpura with the low dose non specific IgG component of anti D immunoglobulin. ACTA ACUST UNITED AC 2019. [DOI: 10.1111/ijlh.1990.12.2.131] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
6
|
Recombinant human IgG1 based Fc multimers, with limited FcR binding capacity, can effectively inhibit complement-mediated disease. J Autoimmun 2017; 84:97-108. [PMID: 28830653 DOI: 10.1016/j.jaut.2017.08.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 08/09/2017] [Accepted: 08/10/2017] [Indexed: 12/13/2022]
Abstract
There is a lack of effective targeted therapies for the treatment of complement dependent diseases. We developed two recombinant Fc multimers, G207 and G211, with limited ability to interact with low/moderate affinity FcγRs, but with high avidity for C1q. These drugs effectively inhibited complement dependent cytotoxicity (CDC) in vitro, and prevented the deposition of C1q, C3b and MAC, on the surface of Ab-opsonized cells. Importantly, these inhibitory effects were both C1q dependent and independent. In order to determine the biologic relevance of our findings, we evaluated the clinical efficacy of these drugs in three different animal models, acute RBC hemolysis, anti-Thy-1 nephritis and passive Heymann's nephropathy (PHN), in which disease pathophysiology relies preferentially on complement activation. While G207 was protective in the anti-Thy-1 nephritis and PHN models, G211 was protective in all of the models tested and could effectively treat PHN. In the anti-Thy-1 nephritis model, G211 prevented the characteristic histologic changes associated with the disease and limited glomerular deposition of C3. Collectively, these data suggest that "complement preferential" Fc multimers offer a novel approach to the treatment of complement mediated diseases.
Collapse
|
7
|
Zhou H, Olsen H, So E, Mérigeon E, Rybin D, Owens J, LaRosa G, Block DS, Strome SE, Zhang X. A fully recombinant human IgG1 Fc multimer (GL-2045) inhibits complement-mediated cytotoxicity and induces iC3b. Blood Adv 2017; 1:504-515. [PMID: 29296968 PMCID: PMC5728453 DOI: 10.1182/bloodadvances.2016001917] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 02/15/2017] [Indexed: 12/16/2022] Open
Abstract
GL-2045 is a recombinant human immunoglobulin G1 (IgG1)-based Fc multimer designed to recapitulate the anti-inflammatory activities of intravenous immunoglobulin (IVIG) on the innate and adaptive immune responses. We used functional in vitro studies to determine if GL-2045 could mimic the modulatory activity of IVIG on complement activation. GL-2045, at log-order lower concentrations than heat-aggregated IgG (HAGG) and IVIG, protected antibody-opsonized cells from complement-dependent cytotoxicity. These protective effects were completely mediated by the higher order multimer fractions of GL-2045 and were partially dependent upon sequestration of C1q. Exposure of serum to GL-2045 and, to a lesser extent, IVIG, resulted in high levels of C4a, limited levels of C3a, and no C5a. In contrast, HAGG induced high levels of C4a, C3a, and C5a. The means by which GL-2045 governed complement activation was dependent on its ability to augment the function of factor H, alone and in combination with factor I, to indirectly limit the alternative form of C3 convertase, with resultant increases in the anti-inflammatory molecule, the "inactive" form of C3b, called iC3b. Although IVIG, like GL-2045, potentiated factor H function, it also directly inhibited the alternative form of C3 convertase. Our findings help elucidate how IVIG, GL-2045, and HAGG regulate complement function. Furthermore, the capacity of GL-2045 to sequester C1q and augment factor H activity, in combination with its ability to generate activation-induced immunomodulatory complement split products, such as iC3b, make it a viable drug candidate for the treatment of diverse complement-mediated diseases.
Collapse
Affiliation(s)
- Hua Zhou
- Department of Otorhinolaryngology-Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, MD
| | | | - Edward So
- Department of Otorhinolaryngology-Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, MD
| | | | | | | | | | | | - Scott E Strome
- Department of Otorhinolaryngology-Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, MD
| | - Xiaoyu Zhang
- Department of Otorhinolaryngology-Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, MD
| |
Collapse
|
8
|
Zhang X, Olsen HS, Chen S, So E, Zhou H, Burch E, Mérigeon EY, Block DS, Strome SE. Anti-CD20 Antibody with Multimerized Fc Domains: A Novel Strategy To Deplete B Cells and Augment Treatment of Autoimmune Disease. THE JOURNAL OF IMMUNOLOGY 2015; 196:1165-76. [PMID: 26695368 DOI: 10.4049/jimmunol.1501755] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Accepted: 11/16/2015] [Indexed: 11/19/2022]
Abstract
We developed a fully recombinant anti-CD20 protein derived from cDNA encoding one Fab domain, two IgG1 Fc regions, the IgG2 hinge, and an isoleucine zipper. This protein, called GB4542, contained both the homodimer and higher-order multimers. Binding studies revealed that GB4542 preferentially bound CD20(+) cells yet also recognized CD20(-)FcγR(+) PBMC. In contrast, a control mAb containing the identical Fab region, GB4500, failed to bind CD20(-)FcγR(+) PBMC. Consistent with these findings, interactions between GB4542 and the canonical FcγRs had substantially lower KD values than correlate interfaces between GB4500 and these receptors. At low concentrations, GB4542 showed enhanced Ab-dependent cellular cytotoxicity, Ab-dependent cellular phagocytosis, and complement-dependent cytotoxicity compared with GB4500. However, at higher concentrations, an Fc analog of GB4542 inhibited anti-CD20 mAb-mediated B cell clearance through direct blocking of both Fc-FcγR interactions and C1q deposition on target cells. Furthermore, the higher-order multimer fraction of GB4542 demonstrated greater binding avidity with the canonical FcγRs and was associated with inhibitory effects observed in Ab-dependent cellular phagocytosis and complement-dependent cytotoxicity assays. These data suggest that GB4542 might have utility in the treatment of autoimmune diseases by combining both mAb-mediated B cell depletion and multimerized Fc-mediated tolerogenic effects.
Collapse
Affiliation(s)
- Xiaoyu Zhang
- Department of Otorhinolaryngology-Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, MD, 21201
| | | | - Shaodong Chen
- Medical College of Xiamen University, Xiamen 361005, China
| | - Edward So
- Department of Otorhinolaryngology-Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, MD, 21201
| | - Hua Zhou
- Department of Otorhinolaryngology-Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, MD, 21201
| | - Erin Burch
- Department of Otorhinolaryngology-Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, MD, 21201
| | | | | | - Scott E Strome
- Department of Otorhinolaryngology-Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, MD, 21201;
| |
Collapse
|
9
|
Niknami M, Wang MX, Nguyen T, Pollard JD. Beneficial effect of a multimerized immunoglobulin Fc in an animal model of inflammatory neuropathy (experimental autoimmune neuritis). J Peripher Nerv Syst 2014; 18:141-52. [PMID: 23781961 DOI: 10.1111/jns5.12022] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Intravenous immunoglobulin (IVIg) is one of the first-line therapies for inflammatory neuropathies. Clinical use of IVIg for these disorders is limited by expense and availability. Here, we investigated a synthetic product alternative to IVIg. The aim of this study was to test the therapeutic efficacy of a novel recombinant polyvalent murine IgG2a Fc compound (stradomer™) in experimental autoimmune neuritis (EAN). Seventy-four Lewis rats were immunized with myelin, randomized into three groups, and were treated with albumin, IVIg, or stradomer at 1% of IVIg dose. Rats were assessed clinically, electrophysiologically, and histologically. The clinical disease severity was evaluated by clinical grading and weight changes. The electrophysiological studies recorded motor conduction velocity (MCV), amplitudes, and latencies of the evoked compound muscle action potential (CMAP) and spinal somatosensory evoked potential. The treatment efficacy of the IVIg and stradomer groups was compared to the albumin (control) group. We demonstrate that stradomer has a similar therapeutic efficacy to human IVIg in EAN. Rats receiving stradomer or IVIg showed significantly lower clinical scores and less prominent weight loss compared with controls. A statistically significant improvement in both MCV and the amplitudes of distal and proximal evoked CMAP was observed in the stradomer and IVIg groups. Finally, treatment with both IVIg and stradomer resulted in statistically less inflammation and demyelinating changes in the sciatic nerve as evidenced by lower histological grade. These results reveal the potential of using fully recombinant multimerized immunoglobulin Fc instead of IVIg for treating inflammatory neuropathies.
Collapse
Affiliation(s)
- Marzieh Niknami
- Department of Neurology, Central Clinical School, University of Sydney, Sydney, Australia
| | | | | | | |
Collapse
|
10
|
Recombinant IgG2a Fc (M045) multimers effectively suppress experimental autoimmune myasthenia gravis. J Autoimmun 2014; 52:64-73. [PMID: 24388113 DOI: 10.1016/j.jaut.2013.12.014] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Accepted: 12/15/2013] [Indexed: 11/20/2022]
Abstract
Myasthenia gravis (MG) is an autoimmune disorder caused by target-specific pathogenic antibodies directed toward postsynaptic neuromuscular junction (NMJ) proteins, most commonly the skeletal muscle nicotinic acetylcholine receptor (AChR). In MG, high-affinity anti-AChR Abs binding to the NMJ lead to loss of functional AChRs, culminating in neuromuscular transmission failure and myasthenic symptoms. Intravenous immune globulin (IVIg) has broad therapeutic application in the treatment of a range of autoimmune diseases, including MG, although its mechanism of action is not clear. Recently, the anti-inflammatory and anti-autoimmune activities of IVIg have been attributed to the IgG Fc domains. Soluble immune aggregates bearing intact Fc fragments have been shown to be effective treatment for a number of autoimmune disorders in mice, and fully recombinant multimeric Fc molecules have been shown to be effective in treating collagen-induced arthritis, murine immune thrombocytopenic purpura, and experimental inflammatory neuritis. In this study, a murine model of MG (EAMG) was used to study the effectiveness of this novel recombinant polyvalent IgG2a Fc (M045) in treating established myasthenia, with a direct comparison to treatment with IVIg. M045 treatment had profound effects on the clinical course of EAMG, accompanied by down-modulation of pathogenic antibody responses. These effects were associated with reduced B cell activation and T cell proliferative responses to AChR, an expansion in the population of FoxP3(+) regulatory T cells, and enhanced production of suppressive cytokines, such as IL-10. Treatment was at least as effective as IVIg in suppressing EAMG, even at doses 25-30 fold lower. Multimeric Fc molecules offer the advantages of being recombinant, homogenous, available in unlimited quantity, free of risk from infection and effective at significantly reduced protein loads, and may represent a viable therapeutic alternative to polyclonal IVIg.
Collapse
|
11
|
Cationized IVIg as a potential substitute to IVIg for the treatment of experimental immune thrombocytopenia. Int Immunopharmacol 2013; 16:409-13. [PMID: 23665226 DOI: 10.1016/j.intimp.2013.04.023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Revised: 04/16/2013] [Accepted: 04/23/2013] [Indexed: 12/21/2022]
Abstract
In this study, we evaluated the possibility of using cationized IVIg (cIVIg) instead of IVIg as a more effective therapy for the treatment of experimental immune thrombocytopenia in mice. The pharmacokinetics (PK) and biodistribution of cIVIg and IVIg in mice were compared. cIVIg displayed a shorter plasma half-life and an increased organ uptake in both the spleen and liver compared to IVIg, suggesting that cIVIg could be more potent than IVIg to prevent platelet clearance in a mouse model of thrombocytopenia. However, although the biodistribution of cIVIg in the spleen and liver was improved, its ability to prevent platelet clearance in mice remained similar to that of IVIg. Altogether, our data demonstrate the possibility of using chemical cationization of IVIg preparations to increase organ uptake, and also highlight the challenges of developing effective substitutes to IVIg.
Collapse
|
12
|
|
13
|
Jain A, Olsen HS, Vyzasatya R, Burch E, Sakoda Y, Mérigeon EY, Cai L, Lu C, Tan M, Tamada K, Schulze D, Block DS, Strome SE. Fully recombinant IgG2a Fc multimers (stradomers) effectively treat collagen-induced arthritis and prevent idiopathic thrombocytopenic purpura in mice. Arthritis Res Ther 2012; 14:R192. [PMID: 22906120 PMCID: PMC3580588 DOI: 10.1186/ar4024] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Accepted: 08/20/2012] [Indexed: 12/21/2022] Open
Abstract
Introduction Soluble immune aggregates bearing intact Fc fragments are effective treatment for a variety of autoimmune disorders in mice. The better to understand the mechanisms by which Fc-bearing immune complexes suppress autoimmunity, and to develop a platform for clinical translation, we created a series of fully recombinant forms of polyvalent IgG2a Fc, termed stradomers, and tested their efficacy in a therapeutic model of collagen-induced arthritis (CIA) and preventive models of both idiopathic thrombocytopenic purpura (ITP) and graft-versus-host disease (GVHD). Methods Stradomers were created by engineering either the human IgG2 hinge sequence (IgG2H) or the isoleucine zipper (ILZ) onto either the carboxy or amino termini of murine IgG2a Fc. Multimerization and binding to the canonical Fc receptors and the C-type lectin SIGN-RI were evaluated by using sodium dodecylsulfate-polymerase chain reaction (SDS-PAGE) and Biacore/Octet assays. The efficacy of stradomers in alleviating CIA and preventing ITP and GVHD was compared with "gold standard" therapies, including prednisolone and intravenous immune globulin (IVIG). Results Stradomers exist as both homodimeric and highly ordered sequential multimers. Higher-order multimers demonstrate increasingly stable associations with the canonic Fcγ receptors (FcγRs), and SIGN-R1, and are more effective than Fc homodimers in treating CIA. Furthermore, stradomers confer partial protection against platelet loss in a murine model ITP, but do not prevent GVHD. Conclusion These data suggest that fully human stradomers might serve as valuable tools for the treatment of selected autoimmune disorders and as reagents to study the function of Fc:FcR interactions in vivo.
Collapse
|
14
|
Tremblay T, Paré I, Bazin R. Immunoglobulin G dimers and immune complexes are dispensable for the therapeutic efficacy of intravenous immune globulin in murine immune thrombocytopenia. Transfusion 2012; 53:261-9. [DOI: 10.1111/j.1537-2995.2012.03725.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
|
15
|
Boughton BJ. The Pathophysiology, Diagnosis and Management of Autoimmune Thrombocytopenia. Platelets 2009; 4:117-22. [DOI: 10.3109/09537109309013206] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
16
|
Boughton BJ, Chakraverty RK, Simpson A, Smith N. The effect of anti-Rho(D) and non-specific immunoglobulins on monocyte Fc receptor function: the role of high molecular weight IgG polymers and IgG subclasses. CLINICAL AND LABORATORY HAEMATOLOGY 2008; 12:17-23. [PMID: 2160875 DOI: 10.1111/j.1365-2257.1990.tb01105.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Anti-Rho(D) immunoglobulin (anti-D) contained more high molecular weight (HMW) IgG polymers than intravenous non-specific immunoglobulin (i.v. Ig). The low-dose anti-D and high-dose i.v. Ig regimens used to treat idiopathic thrombocytopenic purpura (ITP) therefore contained similar total amounts of HMW IgG. In vitro, the HMW IgG polymers were more effective competitive inhibitors of monocyte phagocyte Fc receptors than monomeric IgG. The IgG subclass composition of anti-D and i.v. Ig were both similar to normal human plasma. We conclude that the HMW IgG content but not the IgG subclass composition of anti-D may explain its low-dose therapeutic efficacy in ITP.
Collapse
Affiliation(s)
- B J Boughton
- Department of Haematology, Queen Elizabeth Hospital, Edgbaston, Birmingham
| | | | | | | |
Collapse
|
17
|
Hoehlig K, Lampropoulou V, Roch T, Neves P, Calderon-Gomez E, Anderton SM, Steinhoff U, Fillatreau S. Immune regulation by B cells and antibodies a view towards the clinic. Adv Immunol 2008; 98:1-38. [PMID: 18772002 DOI: 10.1016/s0065-2776(08)00401-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
B lymphocytes contribute to immunity in multiple ways, including production of antibodies, presentation of antigen to T cells, organogenesis of secondary lymphoid organs, and secretion of cytokines. Recent clinical trials have shown that depleting B cells can be highly beneficial for patients with autoimmune diseases, implicating B cells and antibodies as key drivers of pathology. However, it should be kept in mind that B cell responses and antibodies also have important regulatory roles in limiting autoimmune pathology. Here, we analyze clinical examples illustrating the potential of antibodies as treatment for immune-mediated disorders and discuss the underlying mechanisms. Furthermore, we examine the regulatory functions of activated B cells, their involvement in the termination of some experimental autoimmune diseases, and their use in cell-based therapy for such pathologies. These suppressive functions of B cells and antibodies do not only open new ways for harnessing autoimmune illnesses, but they also should be taken into account when designing new strategies for vaccination against microbes and tumors.
Collapse
Affiliation(s)
- Kai Hoehlig
- Laboratory of immune regulation, Deutsches Rheuma-Forschungszentrum, Charitéplatz 1, Berlin, Germany
| | | | | | | | | | | | | | | |
Collapse
|
18
|
Abstract
Evidence suggests that amelioration of childhood immune thrombocytopenic purpura and some other autoimmune states by intravenous normal IgG is due to the following chain of events: (1) cross-linking of Fcgamma-receptors on blood effector cells; (2) release of mediators from these cells, often yielding an infusion-related reaction; (3) mediator-induced development of a cytokine field characterized by a mutually stabilizing Th2 polarization of CD4 T lymphocytes and alternative activation of macrophages; (4) selective quiescence of these macrophages towards targets coated with IgG autoantibody, due to increased expression of the macrophage Fcgamma-receptor IIB. In this paper it is postulated that in the field of antibody therapy of tumor, an undesirable delayed or absent subsidence of antibody-coated tumor is due to immunomodulation of the same type as yields amelioration of autoimmunity, and arising from a similar chain of events. If the postulate is correct the chain could usefully be broken at the level of mediator action, possibly by blocking that increased synthesis of prostaglandin E(2) which is catalyzed by the enzyme cyclooxygenase-2.
Collapse
Affiliation(s)
- George T Stevenson
- Tenovus Research Laboratory, Southampton University Hospitals, Southampton SO16 6YD, UK
| |
Collapse
|
19
|
Teeling JL, Jansen-Hendriks T, Kuijpers TW, de Haas M, van de Winkel JG, Hack CE, Bleeker WK. Therapeutic efficacy of intravenous immunoglobulin preparations depends on the immunoglobulin G dimers: studies in experimental immune thrombocytopenia. Blood 2001; 98:1095-9. [PMID: 11493456 DOI: 10.1182/blood.v98.4.1095] [Citation(s) in RCA: 151] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The clinical benefit of intravenous immunoglobulin (IVIG) preparations in the treatment of immune thrombocytopenic purpura (ITP) is supposed to be mediated by blockade of Fc gamma receptor--bearing phagocytes. In 2 experimental models for ITP, it is shown that the therapeutic efficacy of IVIG preparations is related to the IgG dimer content present in these preparations. A rat monoclonal antibody (mAb; MWReg30) directed to the murine platelet-specific integrin alpha(IIb)beta(3) (gpIIb/IIIa) was administered intraperitoneally either as bolus injection or continuous infusion. With bolus injection, the circulating platelet count dropped to almost zero within 3 hours. Pretreatment with cobra venom factor did not affect platelet depletion, whereas pretreatment with anti-Fc gamma RII/III mAb 2.4G2 or IVIG greatly reduced platelet clearance. With continuous infusion, platelet numbers reached a steady state after 4 days, at approximately 25% of control. This reduction in platelets was, however, not observed in mice deficient for the FcR gamma-chain, lacking Fc gamma RI, Fc gamma RIII, and Fc gamma RIII(-/-) mice. Infusion of a single dose of IVIG with a high IgG dimer content on the 4th day--ie, mimicking therapeutic administration--resulted in a platelet increase for several days. IVIG predominantly consisting of monomeric IgG had no effect on platelet numbers. In conclusion, continuous infusion of MWReg30 induces thrombocytopenia in mice by enhancing Fc gamma receptor--mediated clearance of platelets. In this model, it is shown that IgG dimers present in IVIG preparations are responsible for the increase in platelet counts. (Blood. 2001;98:1095-1099)
Collapse
Affiliation(s)
- J L Teeling
- Central Laboratory of the Netherlands Red Cross Blood Transfusion Service, Academical Medical Center, University of Amsterdam, The Netherlands
| | | | | | | | | | | | | |
Collapse
|
20
|
Dolman C, Thorpe SJ, Thorpe R. Enhanced efficacy of anti-D immunoglobulin for treating ITP is not explained by higher immunoglobulin polymer content. Biologicals 2001; 29:75-9. [PMID: 11580212 DOI: 10.1006/biol.2001.0279] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Several reports have suggested that low dose anti-D immunoglobulin is superior to high dose immunoglobulin for treatment of idiopathic thrombocytopenia purpura (ITP). However, some findings suggest that it is not the anti-D activity per se that is responsible for efficacy for treatment of ITP with anti-D immunoglobulin. Amongst alternative explanations for the mechanism of action is a relatively higher immunoglobulin polymer content of anti-D compared to other immunoglobulin products, which is more efficient in causing reticuloendothelial Fc receptor blockade. In order to investigate this we have evaluated the polymeric IgG content of anti-D and other immunoglobulin products. Different products showed considerable variation in immunoglobulin polymer content. There was no clear correlation between aggregate or dimer content and product type and anti-D as a class of product did not contain higher amounts of either dimer or aggregate compared to other products. Some manufacturers' products increased in polymer content on storage, but others did not show this effect. Therefore, higher immunoglobulin dimer and/or aggregate content cannot explain the increased efficacy of anti-D immunoglobulin for treatment of ITP. The role of polymeric Ig in efficacy for treatment of ITP is unclear.
Collapse
Affiliation(s)
- C Dolman
- Division of Immunobiology, National Institute for Biological Standards and Control, Blanche Lane, South Mimms, Herts, EN6 3QG, UK
| | | | | |
Collapse
|
21
|
Rewald E. Are there options for donor-derived i.m. anti-D IgG preparations other than to prevent Rh(D) sensitization? The intravenous route. TRANSFUSION SCIENCE 1995; 16:383-9. [PMID: 10159509 DOI: 10.1016/0955-3886(95)00049-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The use of i.v. anti-Rh(D) IgG for conditions other than prevention of Rh(D) sensitization is discussed. Besides highlighting the platelet response in ATP, a putative distinctive effect on the hemorrhagic threshold is suggested. Accordingly, we have included discussion of cases of aplastic anemia, myelodysplasia, heavy chemotherapy, coagulation deficiency, and senile vascular atrophy. We have also considered attempts to replace the high-dose pooled i.v. IgG (IVIG) with the much smaller amounts of IgG present in anti-Rh(D) preparations used to prevent Rh-sensitization in pregnancy. Both Fc and variable fragments of the IgG molecule may play a role, the former potentiated by manufacture-induced IgG aggregation and the latter by donor hypersensitization. A role for IgG-anti-F(ab')2 molecules cannot be ruled out.
Collapse
Affiliation(s)
- E Rewald
- Fundación Hematológica, Corrientes, Argentina
| |
Collapse
|
22
|
Jungi TW, Nydegger UE. Proposed mechanisms of action of intravenous IgG (IVIG) in autoimmune diseases. ACTA ACUST UNITED AC 1992. [DOI: 10.1016/0955-3886(92)90138-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
23
|
Rarick MU, Montgomery T, Groshen S, Sullivan-Halley J, Jamin D, Mazumder A, Gill PS, Loureiro C, Levine AM. Intravenous immunoglobulin in the treatment of human immunodeficiency virus-related thrombocytopenia. Am J Hematol 1991; 38:261-6. [PMID: 1746533 DOI: 10.1002/ajh.2830380402] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Fourteen patients with sexually transmitted human immunodeficiency virus (HIV)-related immune thrombocytopenia were treated with intravenous gammaglobulin (IVIG). The patients were treated with a uniform program consisting of 1 g/kg of IVIG on day 1 and day 2, followed by 1 g/kg on day 15. Most patients had pretreatment bleeding symptoms, which included petechiae, spontaneous and traumatic ecchymoses, gum bleeding, and epistaxis. Median baseline platelet count was 17,000/mm3 (range 3-61,000/mm3). After the infusion of the IGIV, all patients had a resolution of their bleeding by day 8. The median maximum platelet count achieved with the IGIV was 220,000/mm3 (range 76-426,000/mm3). No patient achieved either a sustained complete or partial remission after the conclusion of the IVIG therapy. Toxicities were minimal with the majority being headache and nausea. In conclusion, patients with sexually transmitted HIV infection and immune thrombocytopenia respond favorably to IVIG. This treatment should be considered as first-line therapy for patients with HIV-related immune thrombocytopenia who require immediate but temporary increase in their platelet count, attributable to symptoms or signs of clinical bleeding or because of the need for an invasive procedure.
Collapse
Affiliation(s)
- M U Rarick
- Department of Internal Medicine, University of Southern California School of Medicine, Los Angeles
| | | | | | | | | | | | | | | | | |
Collapse
|
24
|
Jungi TW, Brcic M, Kuhnert P, Spycher MO, Li F, Nydegger UE. Effect of IgG for intravenous use on Fc receptor-mediated phagocytosis by human monocytes. Clin Exp Immunol 1990; 82:163-9. [PMID: 2208790 PMCID: PMC1535175 DOI: 10.1111/j.1365-2249.1990.tb05421.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Polyspecific IgG given intravenously at high doses (IVIG) is used for immunomodulatory therapy in autoimmune diseases such as idiopathic thrombocytopenic purpura and myasthenia gravis. It is assumed that the clinical effect is brought about in part by a modulation of mononuclear phagocyte function, in particular by an inhibition of Fc receptor (FcR) mediated phagocytosis. In the present study, the effect of IVIG on FcR-mediated phagocytosis by monocytes was analysed in vitro. Since monocytes exposed to minute amounts of surface-bound IgG displayed impaired phagocytosis of IgG-coated erythrocytes (EA), the effect of IVIG was studied with mononuclear cells suspended in teflon bags in medium containing 10% autologous serum and IVIG (2-10 mg/ml). Monocytes pre-exposed to IVIG and then washed, displayed impaired ingestion of EA when compared with control cells cultured in 10% autologous serum only. The decrease in phagocytosis was observed with sheep erythrocytes treated with either rabbit IgG or bovine IgG1 and with anti-D-treated human erythrocytes. This suggests that phagocytosis via both FcR type I (FcRI) and type II (FcRII) was decreased. The impairment of phagocytosis was dependent on the presence of intact IgG and was mediated by IVIG from nulliparous donors and from multigravidae to the same extent, suggesting that alloantibodies contained in IVIG have a minor role in modulating FcR-mediated phagocytosis by monocytes. A flow cytometric analysis using anti-FcRI, FcRII and FcRII monoclonal antibodies showed that IVIG treatment upregulated FcRI expression but did not significantly alter the expression of FcRII and FcRIII.
Collapse
Affiliation(s)
- T W Jungi
- Institute of Veterinary Virology, University of Berne, Switzerland
| | | | | | | | | | | |
Collapse
|
25
|
Atrah HI, Davidson RJ. Mechanism of action of intravenous immunoglobulin in immune-mediated cytopenias. J Clin Pathol 1988; 41:1249-55. [PMID: 3066800 PMCID: PMC1141755 DOI: 10.1136/jcp.41.12.1249] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- H I Atrah
- Department of Haematology, Aberdeen Royal Infirmary, Foresterhill, Scotland
| | | |
Collapse
|
26
|
Sorensen RU, Kallick MD. Clinical uses of intravenous immune globulin: immunoglobulin replacement therapy and treatment of autoimmune cytopenias. J Clin Apher 1988; 4:97-103. [PMID: 3397376 DOI: 10.1002/jca.2920040212] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Intravenous immune globulin (IVIG) is indicated for IgG replacement in antibody deficiency syndromes and as immunoregulatory therapy in some autoimmune diseases. Two case histories illustrate both aspects of IVIG therapy. 1. Patient 1 is a 24-year-old male with agammaglobulinemia. He was successively treated with monthly IMIG, paternal plasma, and then over the last 5 years, IVIG. On IgG doses of 250 mg/kg q/4 weeks, IgG trough levels remained below 200 mg IgG/dl. IgG half-life was reduced. Although asymptomatic for prolonged periods of time, he eventually developed clinically evident inflammatory bowel disease. Optimal IVIG replacement therapy requires normal IgG half-life and adequate IgG trough levels. 2. Patient 2 is a 12-year-old girl with autoimmune neutropenia, recurrent skin infections, and ileitis unresponsive to antibiotics and to steroid therapy. IVIG at a dose of 3,000 mg/IgG/kg over 3 days significantly increased her neutrophil count. Subsequently, she has required 1,000 mg/kg of IVIG q/4 weeks for maintenance. Antineutrophil autoantibodies have persisted. There is synergism of IVIG with high doses of corticosteroids. The mechanism of action of IVIG seems to involve a blockage of the RES system. IVIG therapy is safe even at high doses for most patients. However, anaphylactic reactions have been observed in IgA-deficient patients with IgE anti-IgA antibodies. The full spectrum of therapeutic applications of IVIG is still being explored. For some patients self-infusion of IVIG at home is an appealing treatment alternative.
Collapse
Affiliation(s)
- R U Sorensen
- Department of Pediatrics, Rainbow Babies and Childrens Hospital, Cleveland, OH 44106
| | | |
Collapse
|
27
|
Cook L, Howard JF, Folds JD. Immediate effects of intravenous IgG administration on peripheral blood B and T cells and polymorphonuclear cells in patients with myasthenia gravis. J Clin Immunol 1988; 8:23-31. [PMID: 2966808 DOI: 10.1007/bf00915153] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Five patients with myasthenia gravis, who received treatment with intravenous 7S gamma-globulin were monitored for changes in immunological status. Serum immunoglobulin G increased from an average of 1.4 to 4.7 g/dl during the 5-day course of therapy. Specific antibody to the acetylcholine receptor present in three of five patients did not change. A transient decrease in total peripheral blood leukocytes was observed in five patients due to decreases in the absolute number of polymorphonuclear cells and lymphocytes in the circulation. Lymphocyte surface marker studies revealed that the percentage of surface immunoglobulin positive cells increased in all patients from an average of 13 to 26% by day 5 of therapy; however, the percentage of HLA-Dr- and Leu 12 (CD19)-positive B cells did not change. Lymphoid cells positive for the Leu 11 (CD16) marker doubled from an average of 11 to 24% during the 5-day course of therapy. Surface Ig-positive cells and Leu 11 (CD16)-positive cells returned to pretreatment values by 7 days posttherapy. Helper/suppressor cell ratios slowly decreased in all patients from an average of 2.9 to 2.2 by 1 week posttherapy and remained low for several weeks.
Collapse
Affiliation(s)
- L Cook
- Clinical Microbiology and Immunology Laboratory, North Carolina Memorial Hospital, Chapel Hill 27514
| | | | | |
Collapse
|
28
|
Atrah HI, Crawford RJ, Gabra GS, Mitchell R. Intravenous immunoglobulin therapy for idiopathic thrombocytopenic purpura. Scott Med J 1986; 31:231-3. [PMID: 3563461 DOI: 10.1177/003693308603100404] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Twenty-two patients with idiopathic thrombocytopenic purpura were treated with high-dose intravenous immunoglobulin infusions using an intact intravenous immunoglobulin preparation and a product designed for intramuscular administration. Seventeen patients (77%) responded favourably (rise in platelet count to 100 X 10(9)/1 or above). Children responded better than the adults, and the acute cases better than the chronic. Splenectomy and the presence of detectable platelet antibody had no effect on the response rate. Both products induced identical responses.
Collapse
|