Evidence-based mini-review: Is indium-labeled autologous platelet scanning predictive of response to splenectomy in patients with chronic immune thrombocytopenia?

Proteomics landscape and machine learning prediction of long-term response to splenectomy in primary immune thrombocytopenia

This study aimed to identify key proteomic analytes correlated with response to splenectomy in primary immune thrombocytopenia (ITP). Thirty-four patients were retrospectively collected in the training cohort and 26 were prospectively enrolled as validation cohort. Bone marrow biopsy samples of all participants were collected prior to the splenectomy. A total of 12 modules of proteins were identified by weighted gene co-expression network analysis (WGCNA) method in the developed cohort. The tan module positively correlated with megakaryocyte counts before splenectomy (r = 0.38, p = 0.027), and time to peak platelet level after splenectomy (r = 0.47, p = 0.005). The blue module significantly correlated with response to splenectomy (r = 0.37, p = 0.0031). KEGG pathways analysis found that the PI3K-Akt signalling pathway was predominantly enriched in the tan module, while ribosomal and spliceosome pathways were enriched in the blue module. Machine learning algorithm identified the optimal combination of biomarkers from the blue module in the training cohort, and importantly, cofilin-1 (CFL1) was independently confirmed in the validation cohort. The C-index of CFL1 was >0.7 in both cohorts. Our results highlight the use of bone marrow proteomics analysis for deriving key analytes that predict the response to splenectomy, warranting further exploration of plasma proteomics in this patient population.

Improving the chances of response to splenectomy in immune thrombocytopenia

Immune thrombocytopenia (ITP) is an autoimmune bleeding disorder characterized by isolated thrombocytopenia. Its pathogenesis is complex relying in large part on destruction of platelets recognized by autoantibodies within the spleen. However, other mechanisms, such as platelet desialylation, may play a role in platelet reduction by accelerating their clearance in the liver. In their study, Mendoza and colleagues reported on platelet scintigraphy performed in 51 ITP patients, showing a response in 87.5% when the sequestration occurred in the spleen versus 45% in case of non-splenic destruction. Platelet desialylation was also measured after splenectomy and found to be higher in non-responder patients. These latter results, while requiring confirmation prior to splenectomy, support platelet desialylation may also be a potential biomarker of non-response to splenectomy. Commentary on: Mendoza et al. Study of platelet kinetics in immune thrombocytopenia to predict splenectomy response. Br J Haematol 2024;204:315-323.

Study of platelet kinetics in immune thrombocytopenia to predict splenectomy response

Despite the efficacy of splenectomy for chronic immune thrombocytopenia (ITP), its considerable failure rate and its possible related complications prove the need for further research into potential predictors of response. The platelet sequestration site determined by 111 In-labelled autologous platelet scintigraphy has been proposed to predict splenectomy outcome, but without standardisation in clinical practice. Here, we conducted a single-centre study by analysing a cohort of splenectomised patients with ITP in whom 111 In-scintigraphy was performed at La Paz University Hospital in Madrid to evaluate the predictive value of the platelet kinetic studies. We also studied other factors that could impact the splenectomy outcome, such as patient and platelet characteristics. A total of 51 patients were splenectomised, and 82.3% responded. The splenic sequestration pattern predicted a higher rate of complete response up to 12 months after splenectomy (p = 0.005), with 90% sensitivity and 77% specificity. Neither age, comorbidities, therapy lines nor previous response to them showed any association with response. Results from the platelet characteristics analysis revealed a significant loss of sialic acid in platelets from the non-responding patients compared with those who maintained a response (p = 0.0017). Our findings highlight the value of splenic sequestration as an independent predictor of splenectomy response.

Is splenectomy a good strategy for refractory immune thrombocytopenia in adults?

Rituximab and thrombopoietin receptor agonists (TPO-RAs) have profoundly changed the management of immune thrombocytopenia (ITP) over the last 20 years. Even if most current guidelines put splenectomy, rituximab and TPO-RAs on the same treatment level, most clinicians and patients clearly prefer to postpone splenectomy and to multiply the lines of medical treatment before considering surgery. The management of ITP refractory to rituximab and TPO-RAs is challenging. Splenectomy is currently performed much less frequently because of a better knowledge of its complications, particularly severe late infections and deep vein thrombosis, and the inability to reliably predict its effectiveness. Furthermore, there is a reluctance to propose splenectomy when other treatments have been ineffective, based on the not well-documented risk that splenectomy could not be effective in such a case. The objective of this update was to review the most recent published data on the long-term tolerability and side effects of splenectomy and the predictors of response and efficacy, especially for patients exposed to multiple medical lines. This update can help physicians and patients with failure of multiple lines of therapy make an informed decision on the indication for splenectomy with the help of up-to-date data.

Older Adults and Immune Thrombocytopenia: Considerations for the Clinician

Many epidemiological studies have shown that the incidence of immune thrombocytopenia (ITP) increases after age 60 years and peaks in patients over age 80 years. Therefore, ITP is a concern for physicians taking care of older patients, especially regarding its diagnosis and management. The diagnostic work-up should exclude other causes of thrombocytopenia and secondary ITP, including myelodysplastic syndrome and drug-induced ITP. The treatment decision is influenced by an increased risk of bleeding, infectious diseases and thrombosis in this population and should take into account comorbidities and concomitant medications such as anticoagulant drugs. First-line treatment is based on short corticosteroids courses and intravenous immunoglobulin, which should be reserved for patients with more severe bleeding complications, with their higher risk of toxic effects as compared with younger patients. Second-line treatment should be tailored to the patient's history, comorbidities and preferences. Preferred second-line treatments are thrombopoietin receptor agonists for most groups and guidelines given their good efficacy/tolerance ratio, but the thrombotic risk is increased in older people. Other second-line options that can be good alternatives depending on the clinical context include rituximab, dapsone, fostamatinib or immunosuppressive drugs. Splenectomy is less often performed but remains an option for fit patients with chronic refractory disease. Emerging treatments such as Syk or Bruton tyrosine kinase inhibitors and FcRn antagonists are becoming available for ITP and may modify the treatment algorithm in the near future. The aim of this review is to describe the particularities of the diagnosis and treatment of ITP in older people, including the response and tolerance to the currently available drugs. We also discuss some situations related to co-morbidities that can frequently lead to adapt the management strategy in older patients.

Immune thrombocytopenia

INTRODUCTION

Primary immune thrombocytopenia (ITP) is an autoimmune disorder characterized by a low platelet count (<100 × 10⁹/L) with an increased risk of bleeding. Recent (2019) guidelines from the International Consensus Report (ICR) expert panel and the American Society of Hematology (ASH) provide updated recommendations for the diagnosis and management of ITP.

AREAS COVERED

The 2019 ICR and ASH guidelines are reviewed, and differences and similarities highlighted. Clinical approaches to the treatment of ITP are discussed, including the role of fostamatinib which is an approved treatment option in adult patients who are refractory to other treatments.

EXPERT OPINION

The 2019 ICR and ASH guidelines reflect recent changes in the management of ITP. Current treatment approaches for ITP are more rational and evidence-based than in the past. Patients should be treated based on their needs rather than on disease stage, and patient-specific outcomes, (e.g. quality of life) should be considered. Whilst corticosteroids are the mainstay of initial ITP treatment their use should be limited. For subsequent treatment, the use of thrombopoietin receptor agonist (TPO-RA) agents, fostamatinib and rituximab in adults is supported by robust evidence. Rituximab and recently approved fostamatinib offer viable alternatives to splenectomy.

"Indium-labelled autologous platelet sequestration studies predict response to splenectomy in immune thrombocytopenia: An Australian experience"

BACKGROUND

Splenectomy is an effective intervention in primary immune thrombocytopenia (ITP). Attempts to define pre-clinical predictors of platelet response to splenectomy are inconsistent. Based on international studies defining the likelihood of platelet response using platelet sequestration, patients with relapsed/refractory ITP being considered for splenectomy at a regional Australian hospital were assessed with ¹¹¹ Indium-labelled autologous platelet sequestration (ILAPS) studies.

AIMS

To audit the use of ILAPS in an Australian setting and define its role in predicting response to splenectomy.

METHODS

A retrospective review of all patients referred for an ILAPS study at a regional hospital was performed. Results for each patient were expressed as an "R" value (spleen/ liver uptake ratio) to quantify the platelet sequestration pattern and outcome post splenectomy, based on platelet counts.

RESULTS

A total of 45 patients were identified, 13 underwent splenectomy and 32 were medically managed. Patients with favourable ILAPS scans (pure or predominant splenic sequestration) demonstrated a superior response post splenectomy (100% overall response rate (ORR), 83.5% complete remission (CR)) compared to those with unfavourable ILAPS scans (mixed or pure hepatic sequestration) (71.4% ORR, 57.1% CR) over 12 months.

CONCLUSIONS

The use of ILAPS in the Australian setting is feasible and this experience confirms larger international studies demonstrating its utility as a predictor of response to splenectomy in ITP. An unfavourable ILAPS scan could be considered a negative predictor of response prompting consideration for other emerging ITP treatments such as thrombopoietin-receptor agonists (TPO-RAs) or B-cell depleting therapy such as Rituximab. This article is protected by copyright. All rights reserved.

Prospective Evaluation of the First Option, Second-Line Therapy in Childhood Chronic Immune Thrombocytopenia: Splenectomy or Immunomodulation

OBJECTIVE

To describe 4 subgroups of pediatric patients treated with splenectomy, hydroxychloroquine, azathioprine, or rituximab as the first-option, second-line treatment for chronic immune thrombocytopenia.

STUDY DESIGN

Selection of patients with chronic immune thrombocytopenia from the French national prospective cohort of pediatric autoimmune cytopenia OBS'CEREVANCE and VIGICAIRE study, treated by splenectomy, hydroxychloroquine, azathioprine, or rituximab as a first second-line treatment.

RESULTS

For 137 patients, treated between 1989 and 2016, the median follow-up after diagnosis and after treatment initiation was 8.5 (2.8-26.4) years and 4.7 (1.1-25.1) years, respectively. Median age at diagnosis and at initiation of treatment were 9 (0.7; 16) and 12 (2; 18.1) years, respectively without significant difference between subgroups. For the whole cohort, 24-month event-free survival was 62% (95% CI 55; 71). It was 85% (95% CI 77; 95) for the 56 patients treated with splenectomy, 60% (95% CI 44; 84) for the 23 patients treated with rituximab, 46% (95% CI 30; 71) for the 24 patients treated with azathioprine, and 37% (95% CI 24; 59) for the 34 patients treated with hydroxychloroquine (log-rank P < .0001). For the splenectomy subgroup, being older than 10 years at splenectomy tended to improve event-free survival (P = .05). Female teenagers with antinuclear antibody positivity benefited from hydroxychloroquine therapy.

CONCLUSIONS

This national study, limiting pitfalls in the analysis of the effects of second-line therapies, showed that splenectomy remains the treatment associated with the better response at 24 months.

Updated international consensus report on the investigation and management of primary immune thrombocytopenia

Over the last decade, there have been numerous developments and changes in treatment practices for the management of patients with immune thrombocytopenia (ITP). This article is an update of the International Consensus Report published in 2010. A critical review was performed to identify all relevant articles published between 2009 and 2018. An expert panel screened, reviewed, and graded the studies and formulated the updated consensus recommendations based on the new data. The final document provides consensus recommendations on the diagnosis and management of ITP in adults, during pregnancy, and in children, as well as quality-of-life considerations.

Splenectomy for immune thrombocytopenia: down but not out

Splenectomy is an effective therapy for steroid-refractory or dependent immune thrombocytopenia (ITP). With the advent of medical alternatives such as rituximab and thrombopoietin receptor antagonists, the use of splenectomy has declined and is generally reserved for patients that fail multiple medical therapies. Splenectomy removes the primary site of platelet clearance and autoantibody production and offers the highest rate of durable response (50% to 70%) compared with other ITP therapies. However, there are no reliable predictors of splenectomy response, and long-term risks of infection and cardiovascular complications must be considered. Because the long-term efficacy of different second-line medical therapies for ITP have not been directly compared, treatment decisions must be made without supportive evidence. Splenectomy continues to be a reasonable treatment option for many patients, including those with an active lifestyle who desire freedom from medication and monitoring, and patients with fulminant ITP that does not respond well to medical therapy. We try to avoid splenectomy within the first 12 months after ITP diagnosis for most patients to allow for spontaneous or therapy-induced remissions, particularly in older patients who have increased surgical morbidity and lower rates of response, and in young children. Treatment decisions must be individualized based on patients' comorbidities, lifestyles, and preferences. Future research should focus on comparing long-term outcomes of patients treated with different second-line therapies and on developing personalized medicine approaches to identify subsets of patients most likely to respond to splenectomy or other therapeutic approaches.

Factors associated with the effect of open splenectomy for immune thrombocytopenic purpura

OBJECTIVE

To assess the effect and complications of open splenectomy (OS) for immune thrombocytopenic purpura (ITP) and determine preoperative factors associated with surgical effect.

METHODS

This was a retrospective analysis of ITP patients who failed medical therapy and were treated with OS between 1997 and 2014 at the Jinshan Hospital, China. Follow-up was 60 months. Surgical effect was determined from platelet counts and bleeding episodes. Complications were assessed including bleeding episodes. Preoperative factors were identified by logistic regression analysis.

RESULTS

Fifty-six patients (48.2 ± 16.2 yr old; 39 females) were included. Disease course was 31.2 ± 48.2 months; 91.1% patients had preoperative platelet count <20 × 10⁹ /L. OS effect at 1 wk, 1 month, 1 yr, and 5 yrs was in 91.1%, 92.9%, 91.1%, and 89.3% patients, respectively. Pneumonia or lower extremity thrombosis occurred in 7.1% patients. Postoperative mild, moderate, and severe bleeding occurred in 33.9%, 50.0%, and 16.1% patients, respectively. No patients required blood transfusion. Mortality was zero. Larger spleen size associated with surgical effect at 1 wk, 1 month, and 1 yr, and lower preoperative minimum platelet count associated with effect at 5 yrs (P < 0.05).

CONCLUSIONS

Open splenectomy is an effective treatment with less complications for the management of ITP. Lower preoperative minimum platelet count associated with successful OS at 5 yrs.

How we manage immune thrombocytopenia in the elderly

With prolonged life expectancy, immune thrombocytopenia (ITP) is frequent in elderly people. In this setting, ITP diagnosis is challenging because of the concern about an underlying myelodysplastic syndrome. Studies of older adults are lacking, and recommendations for treatment are based mainly on expert opinion. The therapeutic strategy differs from that for younger patients and must take into account the greater risk of bleeding and thrombosis, presence of comorbidities, possible impaired cognitive performance or poor life expectancy and concomitant medications, such as anticoagulant and antiplatelet therapy. Steroids and intravenous immunoglobulin (IVIg) therapy remain the first-line treatments in elderly patients, but prolonged treatment with steroids should be avoided and IVIg treatment may lead to renal failure. Splenectomy is less effective than in young patients and risk of thrombosis is increased. Severe co-morbidities can also contraindicate surgery. Therefore, other second-line treatments are frequently preferred. Danazol and dapsone can be an option for the less severe ITP form. Rituximab is a good option except in patients with a history of infection or with hypogammaglobulinaemia. Thrombopoietin agonists are attractive, especially for patients with severe comorbidities or with limited life expectancy but the risk of thrombosis is a concern.

Current Management of Primary Immune Thrombocytopenia

Primary immune thrombocytopenia is an autoimmune disorder of unknown cause affecting both children and adults. The low peripheral blood platelet count is caused by premature platelet destruction by self-reacting antibodies in addition to an impairment of platelet production. The disease is heterogeneous in its pathophysiology, clinical features and responses to treatment. To date, most of the treatments used have been immune-modulating drugs and these contribute to increased morbidity and mortality in patients. A new class of drugs, the thrombopoietin receptor agonists, has been developed for use in ITP. These have gone through randomised controlled trials in large numbers of patients with ITP. These drugs have high efficacy and are well tolerated. In addition, around 30% of patients receiving these drugs are able to stop them and maintain a safe or normal platelet count. Older treatments such as splenectomy are being used less than before, largely because of the introduction of the thrombopoietin receptor agonists. Currently there are trials underway evaluating novel therapies for ITP that will become available over the next few years once the trials are complete.

The choice of second-line therapy in steroid-resistant immune thrombocytopenia: role of platelet kinetics in a single-centre long-term study

Splenectomy is a time-honoured well established approach for patients with steroid-resistant immune thrombocytopenia (ITP). However, due to the more recent availability of therapeutic options alternative to splenectomy, such as rituximab and agonists of the thrombopoietin-receptor, the choice of second-line therapy is challenging. Platelet kinetics has been widely used to predict response to splenectomy. We describe the outcome of 70 chronic ITP patients who performed a platelet kinetic study after failure of front-line corticosteroids and subsequently underwent open splenectomy. After a median follow-up from surgery of 20 years, 62 (88.5%) patients responded to splenectomy and 9 patients (13%) relapsed. Achieving a complete response (CR) significantly predicted a higher probability long-term stable response. The pattern of platelet sequestration was predominantly splenic in 52 patients (74%), predominantly hepatic in 12 patients (17%), and diffuse in 6 (9%). Patients with nonsplenic (diffuse and hepatic) sequestration showed significantly lower overall responses compared to patients with splenic captation (P = 0.002). A nonsplenic sequestration significantly correlated with lower CR rate and, among CR patients, predicted an increased risk of relapse. Also, the probability of stable responses in nonsplenic uptake patients was substantially lower than in patients with splenic uptake (85% vs. 50%, P = 0.0083). Platelet life span and platelet turnover did not correlate with response and relapse rate. Overall, splenic sequestration was able to predict not only a better quality, but also a higher durability of the responses. However, it should be enphasized that the response rate and duration of response even in patients with nonsplenic uptake were similar or even superior to those reported in patients treated with rituximab as first option.

Does the site of platelet sequestration predict the response to splenectomy in adult patients with immune thrombocytopenic purpura?

Splenectomy is the only potentially curative treatment for chronic immune thrombocytopenic purpura (ITP) in adults. However, one-third of the patients relapse without predictive factors identified. We evaluate the predictive value of the site of platelet sequestration on the response to splenectomy in patients with ITP. Eighty-two consecutive patients with ITP treated by splenectomy between 1992 and 2013 were retrospectively reviewed. Platelet sequestration site was studied by (111)Indium-oxinate-labeled platelets in 93% of patients. Response to splenectomy was defined at last follow-up as: complete response (CR) for platelet count (PC) ≥100 × 10(9)/L, response (R) for PC≥30 × 10(9)/L and <100 × 10(9)/L with absence of bleeding, no response (NR) for PC<30 × 10(3)/L or significant bleeding. Laparoscopic splenectomy was performed in 81 patients (conversion rate of 16%), and open approach in one patient. Median follow-up was 57 months (range, 1-235). Platelet sequestration study was performed in 93% of patients: 50 patients (61%) exhibited splenic sequestration, 9 (11%) hepatic sequestration and 14 patients (17%) mixed sequestration. CR was obtained in 72% of patients, R in 25% and NR in 4% (two with splenic sequestration, one with hepatic sequestration). Preoperative PC, age at diagnosis, hepatic sequestration and male gender were significant for predicting CR in univariate analysis, but only age (HR = 1.025 by one-year increase, 95% CI [1.004-1.047], p = 0.020) and pre-operative PC (HR = 0.112 for > 100 versus <=100, 95% CI [0.025-0.493], p = 0.004) were significant predictors of recurrence-free survival in multivariate analysis. Response to splenectomy was independent of the site of platelet sequestration in patients with ITP. Pre-operative platelet sequestration study in these patients cannot be recommended.

Chronic immune thrombocytopenia in children: who needs splenectomy?

In the field of emerging innovative therapies, such as thrombopoietin mimetics, the question of who needs splenectomy remains highly relevant. Removal of the spleen is an accepted and potentially curative treatment of immune thrombocytopenia (ITP) after decades with a favorable economical-effect ratio but with relevant morbidity particularly in the young patients. ITP is rare and splenectomy is performed in a minority of children, which makes its research almost impossible, resulting in a poor standardization of the procedure. Hence, in children, recommendation and decision for splenectomy is individually based and rests on expert opinions. Furthermore, local practice and availability of health products affect the frequency of splenectomy. Current guidelines agree on one point: splenectomy should be postponed for at least 12 months after the initial diagnosis of ITP, due to the high probability of improvement or even spontaneous remission. However, evidence-based data are lacking and splenectomy remains controversial. This article reviews the current literature and delineates controversies and complexities of splenectomy in children with ITP. There is an urgent need for consensus of this procedure in pediatric patients.

[Current treatment of primary immune thrombocytopenia]

Primary immune thrombocytopenia, also termed immune thrombocytopenic purpura (ITP) is an autoimmune disorder characterized by premature platelet destruction and impaired platelet production. Traditional treatment of ITP has predominantly consisted of immune suppression and/or modulation. However, the understanding of the immune mediated impairment of platelet production has led to the development of new treatments that target the thrombopoietin receptor, promoting formation of megakaryocytes and increasing platelet counts. Best practice for the management of ITP has not yet been established because data from comparative studies are lacking. While some disagreement might still remain among experts concerning therapy (when, who, and how should be treated), in recent years different evidence-based practice guidelines have been published to assist healthcare professionals in the diagnosis and treatment of ITP. This review describes the current treatment landscape of ITP.

Splenectomy as a curative treatment for immune thrombocytopenia: a retrospective analysis of 233 patients with a minimum follow up of 10 years

The treatment of choice in steroid-resistant immune thrombocytopenia is still controversial due to the recent advent of new drugs (anti-CD20 antibodies and thrombopoietin mimetics) that have encouraged a generalized tendency to delay splenectomy. Consequently, it is extremely importance to define the efficacy and safety of splenectomy in the long term. We retrospectively analyzed the data of 233 patients affected by immune thrombocytopenia who underwent splenectomy between 1959 and 2001 in 6 European hematologic institutions and who have now a minimum follow up of ten years from surgery. Of the 233 patients, 180 (77%) achieved a complete response and 26 (11%) a response. Sixty-eight of 206 (33%) responsive patients relapsed, mostly (75%) within four years from first response. In 92 patients (39.5%), further treatment was required after splenectomy that was effective in 76 cases (83%). In 138 patients (59%), response was maintained free of any treatment at last contact. No significant association between baseline characteristics and likelihood of stable response was found. Overall, 73 (31%) and 58 (25%) patients experienced at least one infectious or hemorrhagic complication, which was fatal in 2 and 3 patients, respectively. A stable response to splenectomy was associated with a lower rate of infections (P=0.004) and hemorrhages (P<0.0001). Thrombosis developed in 18 patients (8%) and was fatal in 4. Splenectomy achieved a long-term stable response in approximately 60% of cases. Complications mainly affected non-responding patients and were fatal in a minority.

Contemporary management of primary immune thrombocytopenia in adults

Immune thrombocytopenia (ITP) comprises a syndrome of diverse disorders that have in common immune-mediated thrombocytopenia, but that differ with respect to pathogenesis, natural history and response to therapy. ITP may occur in the absence of an evident predisposing etiology (primary ITP) or as a sequela of a growing list of associated conditions (secondary ITP). Primary ITP remains a diagnosis of exclusion and must be differentiated from non-autoimmune etiologies of thrombocytopenia and secondary causes of ITP. The traditional objective of management is to provide a hemostatic platelet count (> 20-30 × 10(9) L(-1) in most cases) while minimizing treatment-related toxicity, although treatment goals should be tailored to the individual patient and clinical setting. Corticosteroids, supplemented with either intravenous immune globulin G or anti-Rh(D) as needed, are used as upfront therapy to stop bleeding and raise the platelet count acutely in patients with newly diagnosed or newly relapsed disease. Although most adults with primary ITP respond to first-line therapy, the majority relapse after treatment is tapered and require a second-line approach to maintain a hemostatic platelet count. Standard second-line options include splenectomy, rituximab and the thrombopoietin receptor agonists, romiplostim and eltrombopag. Studies that directly compare the efficacy, safety and cost-effectiveness of these approaches are lacking. In the absence of such data, we do not favor a single second-line approach for all patients. Rather, we consider the pros and cons of each option with our patients and engage them in the decision-making process.

How I treat immune thrombocytopenia: the choice between splenectomy or a medical therapy as a second-line treatment. Blood. 2012;120:960-969. [PMID: 22740443 DOI: 10.1182/blood-2011-12-309153]

The paradigm for managing primary immune thrombocytopenia (ITP) in adults has changed with the advent of rituximab and thrombopoietin receptor agonists (TPO-RAs) as options for second-line therapy. Splenectomy continues to provide the highest cure rate (60%-70% at 5+ years). Nonetheless, splenectomy is invasive, irreversible, associated with postoperative complications, and its outcome is currently unpredictable, leading some physicians and patients toward postponement and use of alternative approaches. An important predicament is the lack of studies comparing second-line options to splenectomy and to each other. Furthermore, some adults will improve spontaneously within 1-2 years. Rituximab has been given to more than 1 million patients worldwide, is generally well tolerated, and its short-term toxicity is acceptable. In adults with ITP, 40% of patients are complete responders at one year and 20% remain responders at 3-5 years. Newer approaches to using rituximab are under study. TPO-RAs induce platelet counts > 50 000/μL in 60%-90% of adults with ITP, are well-tolerated, and show relatively little short-term toxicity. The fraction of TPO-RA-treated patients who will be treatment-free after 12-24 months of therapy is unknown but likely to be low. As each approach has advantages and disadvantages, treatment needs to be individualized, and patient participation in decision-making is paramount.

Sequence of treatments for adults with primary immune thrombocytopenia

Management of adults with primary immune thrombocytopenia (ITP) has changed dramatically in the past 10 years. New regimens of corticosteroids for first-line treatment have been introduced and are currently being evaluated in a randomized clinical trial. Many patients may not have durable remissions with initial corticosteroid regimens and may require additional, second-line, treatment. For these patients, rituximab has been increasingly used, as it has for other autoimmune disorders, and new thrombopoietin (TPO)-receptor agonists have been developed. Although splenectomy was the first effective and remains the most effective treatment for ITP, inducing durable complete remissions in 66% of patients, rituximab and TPO-receptor agonists are now additional options for second-line treatment. For patients who continue to have severe and symptomatic thrombocytopenia following failure of multiple treatments, including splenectomy and rituximab, the TPO-receptor agonists are effective as third-line treatment for maintaining safe platelets counts to prevent bleeding symptoms in most patients.

Skewed T-cell subsets and enhanced macrophages phagocytosis in the spleen of patients with immune thrombocytopenia failing glucocorticoids

T-cell abnormalities are considered important in the pathogenesis of immune thrombocytopenia (ITP). Th1 polarization of the immune response in peripheral blood mononuclear cells (PBMC) has been observed in ITP patients. However, whether the polarization of T-cell subsets exists in splenocytes remains unclear. In the present study, we detected T-cell subsets and macrophage phagocytosis capacity in the spleens of ten ITP patients failing first-line treatment. Compared with traumatic patients, ITP patients had similar percentages of Th1, Tc1, and T1 (Th1 + Tc1) cells, but lower percentages of Th2 and Tc2 cells, which did not, however, reach significant difference. ITP patients had significantly lower percentages of T2 (Th2 + Tc2) cells than the control group (P = 0.035). The ratios of Th1/Th2 and T1/T2 were significantly higher in ITP patients than the control group (P = 0.025 and 0.027, respectively). Splenic macrophages from ITP patients presented significant increase in phagocytic capacity (P < 0.001). The phagocytosis rate in splenic macrophages positively correlated with the ratio of Th1/Th2 (r = 0.767, P = 0.010), but negatively correlated with percentage of Th2 cells (r = -0.804, P = 0.005). The skewed T-cell subsets and enhanced macrophage phagocytosis in the spleen may be closely related to the disease onset and status of ITP.