The response to high-dose intravenous immunoglobulin or steroids is not predictive of outcome after splenectomy in adults with autoimmune thrombocytopenic purpura

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.

Splenectomy Outcomes in Relapsed or Refractory Immune Thrombocytopenia according to First-Line Intravenous Immunoglobulin Response

OBJECTIVES

Although splenectomy has long been second-line option for immune thrombocytopenia (ITP) patients, an indicator that reliably predicts the efficacy of splenectomy is still being explored. We investigated the treatment outcomes of splenectomy as a second-line therapy for relapsed/refractory ITP according to first-line intravenous immunoglobulin (IVIG) responses.

METHODS

Fifty-two adult patients treated with splenectomy as second-line therapy for ITP between 2009 and 2019 were included, and they were classified according to first-line IVIG responses (no response to IVIG: nonresponders; only transient IVIG response shorter than 4 weeks: poor responders; IVIG response for a longer period; stable responders). The efficacy of splenectomy was analyzed in the three subgroups.

RESULTS

Of the 52 patients, 10 were IVIG nonresponders, 34 were poor responders, and the remaining 8 were stable responders. Response to splenectomy was observed in 50.0% of IVIG nonresponders, 94.1% of poor responders, and 100% of stable responders (p = 0.0030). Among the 45 patients who responded to splenectomy, 51.1% relapsed subsequently, and a significantly lower relapse rate was noted in the stable IVIG responders (12.5%, p = 0.0220) than in nonresponders (60.0%) and poor responders (59.4%).

CONCLUSIONS

First-line IVIG response is indicated as a useful predictive factor for response to splenectomy.

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.

Response to steroids predicts response to rituximab in pediatric chronic immune thrombocytopenia

BACKGROUND

Treatment choice in pediatric immune thrombocytopenia (ITP) is arbitrary, because few studies are powered to identify predictors of therapy response. Increasingly, rituximab is becoming a treatment of choice in those refractory to other therapies.

METHODS

The objective of this study was to evaluate univariate and multivariable predictors of platelet count response to rituximab. After local IRB approval, 565 patients with chronic ITP enrolled and met criteria for this study in the longitudinal, North American Chronic ITP Registry (NACIR) between January 2004 and October 2010. Treatment response was defined as a post-treatment platelet count ≥ 50,000/µl within 16 weeks of rituximab and 14 days of steroids. Treatment response data were captured both retrospectively at enrollment and then prospectively.

RESULTS

Eighty (14.2%) patients were treated with rituximab with an overall response rate of 63.8% (51/80). Univariate correlates of response to rituximab included the presence of secondary ITP and a positive response to steroids. In multivariable analysis, response to steroids remained a strong correlate of response to rituximab, OR 6.8 (95% CI 2.0-23.0, P = 0.002). Secondary ITP also remained a strong predictor of response to rituximab, OR 5.6 (95% CI 1.1-28.6, P = 0.04). Although 87.5% of patients who responded to steroids responded to rituximab, 48% with a negative response to steroids did respond to rituximab.

CONCLUSION

In the NACIR, response to steroids and presence of secondary ITP were strong correlates of response to rituximab, a finding not previously reported in children or adults.

Severe chronic refractory immune thrombocytopenic purpura during childhood: a survey of physician management

BACKGROUND

Physician attitudes regarding management of children with severe chronic immune thrombocytopenic purpura (ITP) have not been recently characterized.

PROCEDURE

We designed a survey of members of the American Society of Pediatric Hematology-Oncology (ASPHO) that described a 5-year-old female with ITP for 1 year who was unresponsive to steroids, IVIG, and anti-D immune globulin and having frequent epistaxis causing interference with her daily activities. A 13-item questionnaire evaluated physician decision-making in this setting.

RESULTS

Two hundred and ninety-seven surveys (35% response rate) were returned, and 295 were evaluable. Thirty-three percent of respondents stated that they would recommend splenectomy for such a child. Of those who would not recommend splenectomy, 67% reported that they would instead treat with rituximab. If initial drug therapy failed, 47% would proceed with splenectomy. Those who reported treating with rituximab initially were more likely to recommend splenectomy following failure than those who preferred other drug therapy (P < 0.0001).

CONCLUSIONS

Physician management of patients with chronic ITP is diverse. With the advent of new treatments such as rituximab and thrombopoetic agents it is critically important to compare their cost, adverse effects and efficacy with splenectomy in order to optimally guide treatment practices.

Splenectomy in children with idiopathic thrombocytopenic purpura: A prospective study of 134 children from the Intercontinental Childhood ITP Study Group

BACKGROUND

Splenectomy is an effective procedure for children and adults with severe or refractory idiopathic thrombocytopenic purpura (ITP). Data regarding pediatric patients are limited.

PROCEDURE

Sixty-eight Intercontinental Childhood ITP Study Group (ICIS) investigators from 57 institutions in 25 countries participated in a splenectomy registry. Data from 153 patients were submitted, of whom 134 had a splenectomy and were analyzed.

RESULTS

The median age at splenectomy was 11.8 (2.7-20.7) years. The median postsplenectomy follow-up was 2.0 (0.1-4.5) years. Pre-splenectomy vaccination was not administered in 21 children (15.7%). Open and laparoscopic splenectomy procedures were performed in 67 and 65 evaluable children, respectively. Surgical technique was not reported in two children. Overall immediate platelet response to splenectomy was achieved in 113 patients (86.3%). Eighty percent of responders maintained their status of response during the following 4 years. Older age, longer duration of ITP, and male gender correlated with a complete response. Post-splenectomy sepsis was reported in seven patients without lethal outcome, although sepsis might be differently defined at participating institutions.

CONCLUSIONS

Splenectomy is effective in children with ITP. Management varies greatly in different institutions. These Registry data may serve as a basis for future clinical trials to assess the indication and timing of splenectomy.

Chronic immune thrombocytopenic purpura in children: a survey of the canadian experience

BACKGROUND

Immune thrombocytopenic purpura (ITP) in children is a common pediatric bleeding disorder with heterogeneous manifestations and a natural history that is not fully understood. To better understand the natural history of chronic ITP and detect response trends and outcomes of therapy, we conducted a 10-year retrospective survey of children from age 1 to 18 years with a diagnosis of chronic ITP.

RESULTS

Data on 198 patients from 8 Canadian Pediatric Hematology/Oncology centers were analyzed. The majority of patients were female (58%), and were previously diagnosed with acute (primary) ITP (85%). The age at diagnosis of chronic ITP ranged from 1.1 to 17.2 years with a mean of 8.2+/-4.4 years. Ninety percent of patients received some form of treatment. Untreated patients had a higher mean platelet count at diagnosis of chronic ITP (P=0.009) despite similarities in mean age at first presentation and mean duration of follow-up. Thirty-four (17%) patients underwent splenectomy. Splenectomized patients tended to be significantly older, had a lower mean platelet count at diagnosis of chronic ITP, and had a longer duration of follow-up.

CONCLUSIONS

The results from this study are consistent with published reports.

Splenectomy in children with chronic ITP: long-term efficacy and relation between its outcome and responses to previous treatments

This retrospective study was conducted to determine whether the response to splenectomy is related to the response to previous treatments. We examined the records of 90 children splenectomized for chronic ITP. Platelet counts were constantly>50x10(9)/L in 68 patients (75%). An improvement in the quality of life was observed in 79 (85%). The success of splenectomy was strongly correlated with a good response to previous treatment. A negative response to any of the prior treatments had no predictive value. This finding is relevant when elective splenectomy is considered as a treatment option.

Predictive factors for successful laparoscopic splenectomy in immune thrombocytopenic purpura: study of clinical and laboratory data

BACKGROUND

Laparoscopic splenectomy (LS) offers better short-term results than open surgery for the treatment of immune thrombocytopenic purpura (ITP), but long-term follow-up is required to ensure its efficacy. The remission rate after splenectomy ranges from 49 to 86% and the factors that predict a successful response to surgical management have not been clearly defined. The goal of this study was to determine the preoperative factors that predict a successful outcome following LS.

METHODS

From February 1993 to December 2003, LS was consecutively performed in a series of 119 nonselected patients diagnosed with ITP (34 men and 85 women; mean age, 41 years), and clinical results were prospectively recorded. Postoperative follow-up was based on clinical records, follow-up data provided by the referring hematologist, and a phone interview with the patient and/or relative. Univariate and multivariate analyses were performed for clinical preoperative variables to identify predictive factors of success following LS.

RESULTS

Over a mean period of 33 months, 103 patients (84%) were available for follow-up with a remission rate of 89% (92 patients, 77 with complete remission with platelet count > 150,000). Eleven patients did not respond to surgery (platelet count < 50,000). Mortality during follow-up was 2.5% (two cases not related to hematological pathology and one case without response to splenectomy). Preoperative clinical variables evaluated to identify predictive factors of response to surgery were sex, age, treatment (corticoids alone or associated with Ig or chemotherapy), other immune pathology, duration of disease, and preoperative platelet count. In a subgroup of 52 patients, we also evaluated the type of autoantibodies and corticoid doses required to maintain a platelet count > 50,000. Multivariate analysis showed that none of the variables evaluated could be considered as predictive factors of response to LS due to the high standard error.

CONCLUSION

Long-term clinical results show that LS is a safe and effective therapy for ITP. However, a higher number of nonresponders is needed to determine which variables predict response to LS for ITP.

Splenectomy for adult chronic idiopathic thrombocytopenic purpura: experience from a single center in China

OBJECTIVES

The aim of this study was to explore the results of Chinese chronic idiopathic thrombocytopenic purpura (ITP) patients who underwent splenectomy (SE).

SUBJECTS AND METHODS

Data of 149 chronic ITP patients were retrospectively analyzed. Relapse-free survival was estimated by Kaplan-Meier analysis. Differences between responders and non-responders were evaluated using the chi-square.

RESULTS

The immediate response rate was 82.6% and the sustained response rate was 63.1%. Twenty-nine patients (19.5%) relapsed during follow-up. The 5-year actuarial relapse-free survival was about 75%. The overall morbidity was 26.1% and mortality was 2.7%. Patients with higher postsplenectomy peak platelet count, shorter time from diagnosis to SE and previous response to IVIG therapy were more likely to have sustained response to SE.

CONCLUSION

SE is potentially a useful therapy to provide long-term control of disease in adults with chronic ITP and is associated with low morbidity and mortality. Postsplenectomy peak platelet count, time from diagnosis to SE and previous response to intravenous immune globulin therapy appear predictive for response to SE.

Intravenous Immunoglobulin for Autoimmune Thrombocytopenic Purpura

Severe autoimmune thrombocytopenic purpura is now commonly treated with high doses of intravenous immunoglobulins (IVIGs). Twenty-four years after this treatment was first demonstrated to be effective, several questions remain to be resolved. We review here current knowledge concerning the frequency and type of side effects and the likely mechanism of action of IVIGs. We suggest that the currently recommended dose of IVIG (2 g/kg) could be halved, that the total dose of IVIG should be administered as a single infusion, that nonresponders could be provided another equal dose on day 3, and that IVIG plus prednisolone should be considered the gold standard for treatment of the most severe forms of the disease. Treatment with anti-D immunoglobulin could be proposed as an alternative if the results recently obtained with high doses (75 microg/kg) are confirmed. Finally, because IVIG has only a transient effect, it cannot be considered a curative treatment for patients with chronic autoimmune thrombocytopenic purpura.

Splenectomy for adult patients with idiopathic thrombocytopenic purpura: a systematic review to assess long-term platelet count responses, prediction of response, and surgical complications

Splenectomy has been a standard treatment for adult patients with idiopathic thrombocytopenic purpura (ITP) for more than 50 years. However, the durability of responses, the ability to predict who will respond, and the frequency of surgical complications with splenectomy all remain uncertain. To better interpret current knowledge we systematically identified and reviewed all 135 case series, 1966 to 2004, that described 15 or more consecutive patients who had splenectomy for ITP and that had data for 1 of these 3 outcomes. Complete response was defined as a normal platelet count following splenectomy and for the duration of follow-up with no additional treatment. Forty-seven case series reported complete response in 1731 (66%) of 2623 adult patients with follow-up for 1 to 153 months; complete response rates did not correlate with duration of follow-up (r = -0.103, P = .49). None of 12 preoperative characteristics that have been reported consistently predicted response to splenectomy. Mortality was 1.0% (48 of 4955 patients) with laparotomy and 0.2% (3 of 1301 patients) with laparoscopy. Complication rates were 12.9% (318 of 2465) with laparotomy and 9.6% (88 of 921 patients) with laparoscopic splenectomy. Although the risk of surgery is an important consideration, splenectomy provides a high frequency of durable responses for adult patients with ITP. (Blood. 2004; 104:2623-2634)

Management of immune thrombocytopenic purpura in adults

Primary immune thrombocytopenic purpura (ITP), also referred to as idiopathic thrombocytopenic purpura, is an organ-specific autoimmune disorder in which antibody-coated or immune complex-coated platelets are destroyed prematurely by the reticuloendothelial system, resulting in peripheral blood thrombocytopenia. The disease is heterogeneous with regard to its severity and clinical course and is unpredictable in its response to therapy. Although the basic underlying pathophysiology of ITP has been known for more than 50 years, current treatment guidelines are based on expert opinion rather than on evidence because of a lack of high-quality clinical trials and research. The only patients for whom treatment is clearly required are those with severe bleeding and/or extremely low platelet counts (< 10 x 10(9)/L). Treatment of patients with ITP refractory to corticosteroids and splenectomy requires careful evaluation of disease severity, patient characteristics related to risk of bleeding, and adverse effects associated with treatment. Clinical trials with numerous new agents are under way, which we hope will add more effective and targeted strategies to our therapeutic armamentarium. We describe a logical and structured approach to the clinical management of ITP in adults, based on a literature review and our personal experience.

T cell receptor VB repertoire diversity in patients with immune thrombocytopenia following splenectomy

In recent years, a pathophysiological role for T cells in immune thrombocytopenia (ITP) has been established. We applied cDNA size distribution analysis of the T cell receptor (TCR) beta-variable (VB) complementarity-determining region 3 (CDR3) in order to investigate T cell repertoire diversity among immune thrombocytopenia patients who had either responded or not responded to splenectomy, and compared them to normal controls. ITP patients who had had a durable platelet response to splenectomy showed a mean 2.8 +/- 2.1 abnormal CDR3 size patterns per patient, similar to healthy volunteers (2.9 +/- 2.0 abnormal CDR3 size patterns). In contrast, patients unresponsive to splenectomy demonstrated evidence of significantly more clonal T cell expansions than patients who had responded to splenectomy or controls (11.3 +/- 3.3 abnormal CDR3 size patterns per patient; P < 0.001). Of the VB subfamilies analysed, VB3 and VB15 correlated with response or non-response to splenectomy, each demonstrating oligoclonality in non-responding patients (P < 0.05). These findings suggest that removal of the spleen may lead directly or indirectly to reductions in T cell clonal expansions in responders, or that the extent of T cell clonality impacts responsiveness to splenectomy in patients with ITP.

Splenectomy versus medical treatment for idiopathic thrombocytopenic purpura

BACKGROUND

Treatment strategies for idiopathic thrombocytopenic purpura (ITP) are still uncertain and its management is primarily empirical. The aim of this study was to investigate the role of splenectomy in the therapy of ITP and to evaluate whether medical or surgical treatment is superior.

METHODS

Ninety-two patients with ITP were included in the study. All of these patients had medical therapy and 38 of them underwent splenectomy subsequently. Follow-up was completed in 91 patients after a median of 64 months.

RESULTS

Side effects of medical therapy were noticed in 32 patients (35%), whereas after surgery only 2 patients (5%) had minor complications. A complete or partial remission was achieved in 35 patients (92%) after splenectomy, whereas this was achieved in only 27 patients (30%) after medical therapy. On multivariate analysis splenectomy and age were the only significant independent factors for complete and partial remission.

CONCLUSIONS

Splenectomy is highly effective and safe in the treatment of ITP and is superior over medical therapy. These results should stimulate the discussion about splenectomy for ITP, possibly establishing evidence-based guidelines for surgical treatment in hematology.

Does treatment with intermittent infusions of intravenous anti-D allow a proportion of adults with recently diagnosed immune thrombocytopenic purpura to avoid splenectomy?

This study explored whether repeated infusions of intravenous anti-D could allow adults with recently diagnosed immune thrombocytopenic purpura (ITP) who had failed an initial steroid course to postpone and ultimately avoid splenectomy. Twenty-eight Rh(+), nonsplenectomized adults with ITP diagnosed within 1 to 11 months and platelet counts 30 x 10(9)/L (30 000/microL) or below were enrolled. Anti-D was infused whenever the platelet count decreased to 30 x 10(9)/L (30 000/microL) or below. "Response" was defined as a platelet increase of more than 20 x 10(9)/L (20 000/microL) to more than 30 x 10(9)/L (30 000/microL) within 7 days of treatment. Patients were a median 3.5 months from ITP diagnosis at enrollment and had received a median of 2 previous therapies, including prednisone in 26 of 28 cases. They were followed for a median 26 months. A total of 93% responded to their initial infusion of anti-D, and 68% repeatedly responded with counts maintained above 30 x 10(9)/L (30 000/microL) using anti-D alone. Currently, 12 (43%) of 28 patients have been off all treatment for more than 6 months without undergoing splenectomy, 6 maintaining counts above 100 x 10(9)/L (100 000/microL). Seven continue on treatment, 8 underwent splenectomy, and 1 was lost to follow-up at 10 months. One patient discontinued anti-D because of toxicity. Patients with platelet counts at least 14 x 10(9)/L (14 000/microL) at enrollment were more likely to discontinue treatment (P <.05). Anti-D was an effective maintenance treatment for two thirds of Rh(+), nonsplenectomized adults with ITP who had failed an initial steroid course. Intermittent infusions of intravenous anti-D allowed more than 40% of these adults to avoid splenectomy and to achieve stable platelet counts off all therapy, even after many months of treatment. Platelet count at study entry was the primary predictor of outcome.

Novel approaches to refractory immune thrombocytopenic purpura

Chronic immune thrombocytopenic purpura (ITP) is an organ-specific autoimmune bleeding disorder in which autoantibodies are directed against the individual's own platelets, resulting in increased Fc-mediated platelet destruction by macrophages in the reticuloendothelial system. Although ITP is primarily mediated by IgG autoantibodies, the production of these autoantibodies is regulated by the influence of T lymphocytes and antigen-presenting cells (APC). There is evidence that enhanced T-helper cell/APC interactions in patients with ITP may play an integral role in IgG antiplatelet autoantibody production. New therapies may improve platelet production, decrease platelet antibody production, and decrease monocyte function and/or B-cell and T-cell activities. Understanding these cellular immune responses in ITP may lead to the development of more specific immunoregulatory therapies for the management of this disease.

Management of adult immune thrombocytopenia

Immune thrombocytopenia (ITP) is a heterogeneous disease with regard to pathogenesis, severity, spontaneous course and response to treatment. Except in patients with severe bleeding tendency and very low platelet counts (< 10 x 10(9)/L), there are no clear rules on the indications for treatment. The standard initial therapy is corticosteroids, but the optimal dose and duration of therapy is unknown and in practice, some patients may be overtreated by aiming for complete remission (CR). In patients who have no sustained response after steroids, the most effective single therapy is splenectomy. Laparascopic splenectomy has a very low mortality and moderate morbidity. Preoperative prediction of success is difficult. About 50% of patients are in CR or partial remission after 5 years, but there are few data on the long-term outcome. Patients who fail steroids and splenectomy are difficult to treat. The choice may be palliative, with low doses of steroids or aggressive therapy with the intention of sustained remission. In selected patients, high-dose immunoglobulin or anti-D may be useful to temporarily raise the platelet count. Other drugs tried in ITP had either no or very limited clinically meaningful efficacy.

Management of immune thrombocytopenic purpura in children

Immune thrombocytopenic purpura (ITP) is the most common acquired bleeding disorder occurring in previously healthy children and can be classified into two major forms. Acute and chronic ITP are benign conditions with a high probability of spontaneous recovery with or without therapy. Rates of 80-90% complete remission can be achieved irrespective of the treatment given. In only 10-20% of children thrombocytopenia persists for more than six months, showing a chronic course, which also has a high probability of remitting over time (up to 80% or more). The variability of the clinical course, and the lack of consistent clinical features, make the decision on whether and how to treat difficult. Most physicians are driven to treat all children with symptoms by concern over life-threatening hemorrhage, although the risk of intracranial hemorrhage (ICH) is only 0.1-0.9%. The commonly used treatment regimens for acute ITP are corticosteroids, intravenous immunoglobulins (IVIgG), or intravenous anti-D immunoglobulin (anti-D). So far, there is no evidence that initial therapy can prevent ICH or a chronic course of the disease. In chronic ITP the same drugs are generally used and it seems that pulses with steroids may be just as effective as IVIgG. Anti-D may also be considered a reliable and cheap alternative for chronic disease. A major problem in the management of chronic ITP is the question of whether repeated infusions of Ig (IVIgG or anti-D) and/or corticosteroids can postpone or ultimately preclude splenectomy, which must be considered only for a small proportion of patients resistant to therapy. In these cases, a laparoscopic approach should be preferred. Children who fail to respond to splenectomy (< 20% of cases) warrant second line treatment with other drugs, like cyclophosphamide or azathioprine and deserve a revisit of diagnosis for exclusion of secondary ITP.

Response to high-dose intravenous immune globulin as a valuable factor predicting the effect of splenectomy in chronic idiopathic thrombocytopenic purpura patients

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 x 10(9)/l), incomplete response (IR, (50-150) x 10(9)/l), and complete response (CR, >150 x 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 high-dose 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.

Approach to the investigation and management of immune thrombocytopenic purpura in children

Childhood immune thrombocytopenic purpura (ITP) is typically a benign, self-limiting disorder occurring in young (<10 years of age) previously healthy children. More than 80% of such children enter a complete sustained remission within a few weeks to a few months of initial presentation, irrespective of any therapy given. The major concern is the small but finite (0.1 to 0.9%) risk of intracranial hemorrhage, which occurs in children with very low platelet counts (<20 x 10(9)/L), and is the justification for treatment to increase the circulating platelet count. Effective treatment strategies are single-dose intravenous immunoglobulin G (IVIgG; approximately 1 g/kg) and medium to high-dose corticosteroids, administered orally or parenterally. The necessity for initial bone marrow aspiration and hospitalization continues to be debated. In children with chronic ITP, defined by persistence of thrombocytopenia for > or =6 months, splenectomy should be considered for the relatively small subgroup with symptomatic, severe thrombocytopenia who have either failed an adequate trial (> or = 12 months) of primary therapy (IVIgG, intravenous anti-D, corticosteroids) or are intolerant of such therapy. Laparoscopic splenectomy is preferred over open splenectomy. Children who fail to respond to splenectomy ( < or = 20% of cases) should be evaluated for the presence of accessory spleens; their management is often difficult and must be individualized. In severe refractory cases, second-line therapies (such as azathioprine or vinca alkaloids) need to be considered. Secondary ITP in children is relatively rare and is sometimes associated with other autoimmune cytopenias (Evan's syndrome, ITP with autoimmune neutropenia). These cases often respond poorly to conventional medical therapies and response rates to splenectomy are considerably lower than in children with primary chronic ITP.