Long-term complications of splenectomy in adult immune thrombocytopenia

Risk-based and individualised management of bleeding and thrombotic events in adults with primary immune thrombocytopenia (ITP)

Although bleeding is one of the main symptoms of primary immune thrombocytopenia (ITP), risk factors for bleeding have yet to be fully established. Low platelet count (PC; <20-30 × 109 /L) is generally indicative of increased risk of bleeding. However, PC and bleeding events cannot be fully correlated; many other patient- and disease-related factors are thought to contribute to increased bleeding risk. Furthermore, even though ITP patients have thrombocytopenia and are at increased risk of bleeding, ITP also carries higher risk of thrombotic events. Factors like older age and certain ITP treatments are associated with increased thrombotic risk. Women's health in ITP requires particular attention concerning haemorrhagic and thrombotic complications. Management of bleeding/thrombotic risk, and eventually antithrombotic therapies in ITP patients, should be based on individual risk profiles, using a tailored, patient-centric approach. Currently, evidence-based recommendations and validated tools are lacking to support decision-making and help clinicians weigh risk of bleeding against thrombosis. Moreover, evidence is lacking about optimal PC for achieving haemostasis in invasive procedures settings. Further research is needed to fully define risk factors for each event, enabling development of comprehensive risk stratification approaches. This review discusses risk-based and individualised management of bleeding and thrombosis risk in adults with primary ITP.

The transcriptomic profile shows the protective effects of celecoxib on cirrhotic splenomegaly

BACKGROUND

Splenomegaly can exacerbate liver cirrhosis and portal hypertension. We have previously demonstrated that cyclooxygenase-2 (COX-2) inhibitor can attenuate cirrhotic splenomegaly. However, the mechanism of cirrhotic splenomegaly remains unclear, thus becoming the focus of the present study.

MATERIALS AND METHODS

Thioacetamide (TAA) intraperitoneal injection was used to induce cirrhotic splenomegaly. Rats were randomized into the control, TAA and TAA + celecoxib groups. Histological analysis and high-throughput RNA sequencing of the spleen were conducted. Splenic collagen III, α-SMA, Ki-67, and VEGF were quantified.

RESULTS

A total of 1461 differentially expressed genes (DEGs) were identified in the spleens of the TAA group compared to the control group. The immune response and immune cell activation might be the major signaling pathways involved in the pathogenesis of cirrhotic splenomegaly. With its immunoregulatory effect, celecoxib presents to ameliorate cirrhotic splenomegaly and liver cirrhosis. Furthermore, 304 coexisting DEGs were obtained between TAA vs. control and TAA + celecoxib vs. TAA. Gene ontology (GO) and KEGG analyses collectively indicated that celecoxib may attenuate cirrhotic splenomegaly through the suppression of splenic immune cell proliferation, inflammation, immune regulation, and fibrogenesis. The impacts on these factors were subsequently validated by the decreased splenic Ki-67-positive cells, macrophages, fibrotic areas, and mRNA levels of collagen III and α-SMA.

CONCLUSIONS

Celecoxib attenuates cirrhotic splenomegaly by inhibiting splenic immune cell proliferation, inflammation, and fibrogenesis. The current study sheds light on the therapeutic strategy of liver cirrhosis by targeting splenic abnormalities and provides COX-2 inhibitors as a novel medical treatment for cirrhotic splenomegaly.

Splenectomy outcomes in immune cytopenias: Treatment outcomes and determinants of response

BACKGROUND

Splenectomy is commonly used to treat refractory immune-mediated cytopenia, but there are no established factors that are associated with response to the procedure.

OBJECTIVES

A cohort study was conducted to evaluate the hematologic and surgical outcomes of splenectomy in adult patients with immune cytopenias and identify preoperative factors associated with response.

METHODS

Data from the Cleveland Clinic Foundation for 1824 patients aged over 18 who underwent splenectomy from 2002 to 2020 were analyzed.

RESULTS

The study found that the most common indications for splenectomy were immune thrombocytopenic purpura (ITP) and autoimmune hemolytic anemia, with a median age of 55 years and median time from diagnosis to splenectomy of 11 months. Hematologic response rates were 74% overall, with relapse in 12% of cases. Postsplenectomy discordant diagnoses were present in 13% of patients, associated with higher relapse rates. Surgery-related complications occurred in 12% of cases, whereas only 3% of patients died from disease complications. On univariate analysis, preoperative factors associated with splenectomy treatment failure were ≥3 lines of pharmacologic treatment, whereas isolated thrombocytopenia, primary ITP, and age ≤40 years had a strong association with response. The multivariable regression confirmed that treatment failure with multiple lines of medical therapy was associated with the failure to respond to splenectomy.

CONCLUSION

Overall, the study demonstrates that splenectomy is an effective treatment option for immune-mediated cytopenias with a low complication rate.

How I diagnose and treat thrombocytopenia in geriatric patients

ABSTRACT

Thrombocytopenia in older individuals is a common but diagnostically challenging condition that has variable clinical impact to those who are affected. Diagnostic approach requires evaluation of the preexisting clinical conditions, detailed review of medications, and assessment for disorders that warrant urgent treatment. In this article, we describe a systematic approach to diagnosis of thrombocytopenia and present a schematic review for management strategies. Three clinical scenarios are presented that are relevant for their prevalence and management challenges in an older adult population. The first scenario addresses primary immune thrombocytopenia (ITP) and reviews different treatment options. The second one addresses complications of thrombocytopenia in management of the myelodysplastic syndrome. The last one reviews diagnostic challenges of drug-induced ITP.

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.

Combining thrombopoietin receptor agonists with immunosuppressive drugs in adult patients with multirefractory immune thrombocytopenia, an update on the French experience

Combining drugs could be an effective option for treating multirefractory ITP, that is, patients not responding to rituximab, thrombopoietin receptor agonists (TPO-RA) and splenectomy. We conducted a retrospective, multicenter, observational study including multirefractory ITP patients who received a combination of a TPO-RA and an immunosuppressive drug. We included 39 patients (67% women, median age 59 years [range 21-96]), with a median ITP duration of 57 months [3-393] and a median platelet count at initiation of 10 × 109 /L [1-35]. The combination regimen was given for a median duration of 12 months [1-103] and included eltrombopag (51%) or romiplostim (49%), associated with mycophenolate mofetil (54%), azathioprine (36%), cyclophosphamide (5%), cyclosporin (3%) or everolimus (3%). Overall, 30 patients (77%) achieved at least a response (platelet count ≥30 × 109 /L and at least doubling baseline during at least 3 months), including 24 complete responses (platelet count >100 × 109 /L during at least 3 months) with a median time to response of 30 days [7-270] and a median duration of response of 15 months [4-63]. Severe adverse event related to ITP treatment was observed in 31%. In conclusion, this study confirms that some patients with multirefractory ITP can achieve long lasting response with this combination.

Current approaches for the diagnosis and management of immune thrombocytopenia

Immune thrombocytopenia (ITP), is an acquired autoimmune disorder characterized by the destruction of platelets and megakaryocytes, resulting in thrombocytopenia (platelet count <100 × 10⁹/L). This review focuses on the diagnosis and current management of ITP. The diagnosis of ITP is based principally on the exclusion of other causes of isolated thrombocytopenia using patient history, physical examination, blood count, and evaluation of the peripheral blood film. The clinical treatment goals should be to resolve bleeding events and to prevent severe bleeding episodes. The platelet count should be improved to attain a minimum of > 20-30 × 10⁹/L. Therapy should be given as an inpatient in newly diagnosed ITP with a platelet count of > 20 × 10⁹/L or if there is active bleeding. Corticosteroids are considered the standard initial treatment for newly diagnosed patients. Subsequent medical therapies with robust evidence include thrombopoietin receptor agonists (TPO-RAs), rituximab and fostamatinib. Surgical therapy with splenectomy may be considered for patients failing medical therapy. The choice between therapy options is highly dependent upon patient values and preferences.

[Splenic dysfunction in sickle cell disease: An update]

The spleen filters blood cells and contributes to the immune defense. The red pulp clears the blood from altered red blood cells via its unique microcirculatory network ; while the white pulp is a secondary lymphoid organ, directly connected to the bloodstream, whose specificity is the defense against encapsulated bacteria through the production of "natural" IgM in the marginal zone. Various health conditions can cause acquired impairment of the splenic function (or hyposplenism) directly and/or through therapeutic splenectomy. Hypo/asplenia is complicated by an increased susceptibility to encapsulated germ infections, but an increased risk of thrombosis and pulmonary hypertension has also been reported after surgical splenectomy. Homozygous sickle cell disease is the most common disease associated with functional asplenia. The latter appears early in childhood likely through repeated ischemic alterations caused by the sickling of red blood cells. In addition, specific complications such as hypersplenism and acute splenic sequestration can occur and may be life-threatening. We provide here an update on the role and physiology of the spleen, which will allow a better understanding of the pathophysiology of spleen damage and its consequences in sickle cell disease.

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.

How we treat primary immune thrombocytopenia in adults

Primary immune thrombocytopenia (ITP) is an immune-mediated bleeding disorder characterized by decreased platelet counts and an increased risk of bleeding. Multiple humoral and cellular immune abnormalities result in accelerated platelet destruction and suppressed platelet production in ITP. The diagnosis remains a clinical exclusion of other causes of thrombocytopenia. Treatment is not required except for patients with active bleeding, severe thrombocytopenia, or cases in need of invasive procedures. Corticosteroids, intravenous immunoglobulin, and anti-RhD immunoglobulin are the classical initial treatments for newly diagnosed ITP in adults, but these agents generally cannot induce a long-term response in most patients. Subsequent treatments for patients who fail the initial therapy include thrombopoietic agents, rituximab, fostamatinib, splenectomy, and several older immunosuppressive agents. Other potential therapeutic agents, such as inhibitors of Bruton's tyrosine kinase and neonatal Fc receptor, are currently under clinical evaluation. An optimized treatment strategy should aim at elevating the platelet counts to a safety level with minimal toxicity and improving patient health-related quality of life, and always needs to be tailored to the patients and disease phases. In this review, we address the concepts of adult ITP diagnosis and management and provide a comprehensive overview of current therapeutic strategies under general and specific situations.

Cost-effectiveness of second-line therapies in adults with chronic immune thrombocytopenia

Major options for second-line therapy in adults with chronic immune thrombocytopenia (ITP) include splenectomy, rituximab, and thrombopoietin receptor agonists (TRAs). The American Society of Hematology guidelines recommend rituximab over splenectomy, TRAs over rituximab, and splenectomy or TRAs while noting a lack of evidence on the cost-effectiveness of these therapies. Using prospective, observational, and meta-analytic data, we performed the first cost-effectiveness analysis of second-line therapies in chronic ITP, from the perspective of the U.S. health system. Over a 20-year time-horizon, our six-strategy Markov model shows that a strategy incorporating early splenectomy, an approach at odds with current guidelines and clinical practice, is the cost-effective strategy. All four strategies utilizing TRAs in the first or second position cost over $1 million per quality-adjusted life-year, as compared to strategies involving early use of splenectomy and rituximab. In a probabilistic sensitivity analysis, early use of splenectomy and rituximab in either order was favored in 100% of 10 000 iterations. The annual cost of TRAs would have to decrease over 80% to begin to become cost-effective in any early TRA strategy. Our data indicate that effectiveness of early TRA and late TRA strategies is similar with the cost significantly greater with early TRA strategies. Contrary to current practice trends and guidelines, early use of splenectomy and rituximab, rather than TRAs, constitutes cost-effective treatment in adults with chronic ITP.

Nationwide Survey on the Use of Thrombopoietin Receptor Agonists (TPO-RA) for the Management of Immune Thrombocytopenia in Current Clinical Practice in Italy

Background

Two thrombopoietin receptor agonists (TPO-RA), romiplostim and eltrombopag, are currently widely adopted as second-line ITP therapy even in the absence of robust evidence on their comparative advantages over rituximab or splenectomy or their preferential use in some specific clinical contexts.

Methods

An online survey was distributed between May 2021 and June 2021 to collect standardized information on TPO-RA use in Italy.

Results

Eighty-eight hematologists from 79 centers completed the survey. Eighty-four percent would use TPO-RA earlier than formally indicated, without a preference for young or elderly in 82% of respondents. No clear preference for either romiplostim or eltrombopag was indicated. Seventy-two percent would use TPO-RA in young patients aiming at a complete response followed by tapering, a strategy considered by only 16% in the elderly. Switching between the two agents was considered appropriate in case of insufficient response or intolerance. Tapering schedule by reducing the dosage and prolonging the intervals between administrations was preferred by 73% of respondents. TPO-RA was considered a risk factor for thrombosis by only 35%, and 94% would administer TPO-RA in elderly patients also in the presence of other thrombotic risk factors. Thirty-three percent of respondents would withdraw TPO-RA in case of thrombosis. The TPORA administration has been reported to be preferred over anti-CD20 or splenectomy by about half of the participants due to the ongoing COVID-19 pandemic.

Conclusions

Significant discrepancies in TPO-RA use emerged from the survey, and participants would appreciate consensus-based specific guidance on the practical use of TPO-RA.

Splenectomy outcomes in patients with autoimmune cytopenias and persistent antiphospholipid antibodies

BACKGROUND

Splenectomy is a therapy for patients with treatment-refractory autoimmune cytopenias. Antiphospholipid antibodies (aPL) can be identified in 25%-85% of these patients. In this study, we sought to identify whether the presence of aPL was associated with worse outcomes in autoimmune cytopenia's patients who had undergone splenectomy.

METHODS

We conducted a retrospective cohort study of patients who underwent splenectomy from 2000 to 2018. We describe clinical characteristics and outcomes in patients with autoimmune cytopenia's diagnosis with positive determinations of aPL. Additionally, we performed a case-control sub-analysis 1:1 of the cases with autoimmune cytopenia's matched control patients with negative aPL determination.

RESULTS

A splenectomy was performed in 707 patients, of which we included 34 for the analysis. The median age at the time of splenectomy was 37 years (range 19-61), 53% corresponded to immune thrombocytopenia (ITP) and 47% to autoimmune hemolytic anemia (AIHA). Compared with controls (n = 34), patients had more treatment lines in addition to steroids (p = .02). There were no differences in complete response rate, 65% in cases and 80% in controls (p = .17). However, there was numerically a higher incidence of early infections (21% of cases vs. 3% controls, p = .05). During the entire follow-up, 15% of aPL patients compared with 9% of control patients had a thrombotic event (p = .70).

DISCUSSION

Splenectomy for treatment-refractory autoimmune cytopenia's patients with persistent aPL is an effective treatment despite some safety concerns related to early infections. These results suggest that the presence of aPL should not impact the decision to undergo splenectomy.

Bacterial Etiology of Fever Episodes of Splenectomized Patients in Three Medical Centers in the City of Mashhad in Northeastern Iran

Background: Many medical and surgical conditions may need to be treated with splenectomy. As this lymphoid tissue plays an important role in controlling various infections, and many life-threatening infections can occur in the absence of the spleen, any episode of fever should be taken seriously. Objectives: This study aims to assess the bacterial etiology of fever episodes in splenectomized patients in three medical centers in Mashhad, a city in northeastern Iran. Methods: Between 2006 and 2017, splenectomized patients in Imam Reza, Ghaem, and Dr. Sheikh hospitals were included in a cross-sectional study. Data collected included, age at splenectomy, hospitalization duration, indications for admission to the intensive care unit, vital signs at admission, bacterial species responsible for sepsis, times of hospitalization due to fever episodes, clinical signs and symptoms, antibiotic prophylaxis, and outcomes at six and one years. The data were analyzed using SPSS Statistics 20. Results: A total of 280 splenectomized patients were reviewed, and 23 of them had episodes of fever. The most common causes of splenectomy were spleen masses and idiopathic thrombocytopenic purpura (ITP), each accounting for 17.4% of cases. The mean age of the patients was 24.2 ± 1.6 years. 47.8% of the patients were male, and 52.2% were female. The median admission duration was seven days. A majority of admissions were due to intra-abdominal infections (26.7%), pneumonia (13.3%), and bacteremia (10.0%). There were 30 episodes of fever recorded, of which 2 (6.7%) resulted in death. Blood culture was positive in four cases (13.3%) for Streptococcus pneumoniae, Staphylococcus aureus, Citrobacter, and Brucella. A suitable antibiotic coverage was obtained in 13.3% of cases (i.e., ceftriaxone + vancomycin or fluoroquinolone + vancomycin), and a minimum suitable empiric coverage was obtained in 10.0% of cases, and no appropriate antibiotic coverage was obtained in 76.7% of cases. Conclusions: The present study highlights widespread inappropriate empiric therapy of fever episodes in splenectomized patients, as well as a lack of due attention to timely sample collection before antibiotic administration. Despite this, the isolated organisms were varied and included S. pneumoniae, S. aureus, coagulase negative staphylococci, P. aeruginosa, Brucella, and Citrobacter.

Splenectomy for primary immune thrombocytopenia revisited in the era of thrombopoietin receptor agonists: New insights for an old treatment

Although splenectomy is still considered the most effective curative treatment for immune thrombocytopenia (ITP), its use has significantly declined in the last decade, especially since the approval of thrombopoietin receptor agonists (TPO-RAs). The main objective of the study was to determine whether splenectomy was still as effective nowadays, particularly for patients with failure to respond to TPO-RAs. Our secondary objective was to assess, among patients who relapsed after splenectomy, the pattern of response to treatments used before splenectomy. This multicenter retrospective study involved adults who underwent splenectomy for ITP in France from 2011 to 2020. Response status was defined according to international criteria. We included 185 patients, 100 (54.1%) and 135 (73.0%) patients had received TPO-RAs and/or rituximab before the splenectomy. The median follow-up after splenectomy was 39.2 months [16.5-63.0]. Overall, 144 (77.8%) patients had an initial response and 23 (12.4%) experienced relapse during follow-up, for an overall sustained response of 65.4%, similar to that observed in the pre-TPO-RA era. Among patients who received at least one TPO-RA or rituximab before splenectomy, 92/151 (60.9%) had a sustained response. Six of 13 (46%) patients with previous lack of response to both TPO-RAs and rituximab had a sustained response to splenectomy. Among patients with relapse after splenectomy, 13/21 (61.2%) patients responded to one TPO-RAs that failed before splenectomy. In conclusion, splenectomy is still a relevant option for treating adult primary ITP not responding to TPO-RAs and rituximab. Patients with lack of response or with relapse after splenectomy should be re-challenged with TPO-RAs.

Immune thrombocytopenia: options and new perspectives

Immune thrombocytopenia is a haematological, autoimmune disorder characterized by elevated platelet demolition due to the presence of antiplatelet autoantibodies derived from B cells and to an irregular, deficient process of platelets production in bone marrow. In this review, after a brief presentation of 'old' strategies used nowadays yet, we focused on new drugs used in the treatment of immune thrombocytopenia and their mechanism of action and posology, basing on the last scientific literature. The observation that CoViD-19 can be associated with immune thrombocytopenia is also put in evidence. Particular attention will be dedicated on the concept that the ideal treatment should represent a solution not only for the failure of normal processes of production and survival of platelets, but also it should improve quality of life of patients, with minimum adverse events. Anyway, despite enormous advances of the last years, further investigations are necessary in order to define scrupulously long-term efficacy of new molecules proposed.

Risk of infection in adult patients with primary immune thrombocytopenia (ITP): a systematic review

INTRODUCTION

Primary immune thrombocytopenia (ITP) is a bleeding disorder characterized by autoimmune destruction and impaired production of platelets. Immunosuppressive drugs are the main treatment and may increase risk of infection.

AREAS COVERED

This systematic review included studies incorporating adult patients with primary ITP and infectious outcomes. Studies comparing risk of infection with the general population were included as primary and studies without this comparison were considered secondary. Three primary and 10 secondary studies were included. The main findings: 1-year adjusted relative-risk of infection was 4.5 (95% CI, 3.3-6.1) fold elevated compared to the general population. When comparing splenectomized with non-splenectomized ITP patients, the +1-year adjusted relative-risk of infection was 4.0 (95% CI, 2.8-5.6). The unadjusted 5-year mortality rate-ratio for infection-related deaths was 6.0 (95% CI, 3.0-11.8) in one study, and the hazard ratio was 2.4 (95% CI, 1.0-5.7) for fatal infections in another.

EXPERT OPINION

This review emphasizes that patients with ITP have increased risk of infection. Since ITP is a benign hematologic disease, it is important to assess the extent and causes of infection in the clinical care and considerations before initiating treatment. More homogeneous studies are needed on this topic.

Safety and efficacy of splenectomy in immune thrombocytopenia

BACKGROUND

Immune Thrombocytopenia (ITP) is characterized by low platelet counts. Splenectomy has been in practice for the treatment of ITP since the early 20th century. We aimed to analyze the data of ITP patients from our hospital who underwent splenectomy and further present the long-term outcome and safety profile in these patients.

METHOD

This study was a single-center, registry based study conducted at a tertiary care hospital in Northern India. Patients aged 18 years or more, who underwent splenectomy after at least one line of therapy, were included in the study. The primary outcome was the overall response rate (ORR) at one month after splenectomy. Secondary outcomes were sustained response, relapse-free survival, factors affecting the ORR, and adverse events after splenectomy.

RESULTS

Forty-five patients of ITP were included in the study. Thirty-six patients underwent splenectomy in the first half (2001-2010), of the study period. The median age of the patients was 38 (19-56) years. The median duration from diagnosis to splenectomy was 1.76 (0.47-2.58) years. The median number of therapy received before splenectomy was 3 (1-6). The overall response rate (ORR) post-splenectomy at day 30 was 89.2% with 61.8% complete response (CR). The ORR was 88.5% at 1-year, with 48.8% CR. The relapse-free survival (RFS) at 5-years was 57.38% (95% Confidence Interval 40.59-71.02%), There was no effect of duration of disease, age, gender, and prior therapy received, on the ORR at one-month. At one year, the platelet response was significantly better in patients who had a CR at one-month than patients who had a partial response at one month. The relapse-free survival was better in patients who achieved CR after 1-month of splenectomy. During the median follow-up of 5.02 (1 month-20 years) years, there were five cases of overwhelming post-splenectomy infection (OPSI). There was no recorded incidence of perioperative mortality, deep vein thrombosis, or mesenteric thrombosis.

DISCUSSION

Despite the variation in outcome from different studies, splenectomy gives the best possible long-term treatment-free remission amongst all the available second-line agents. It is also, one of the most financially affordable therapies. Despite advantages, the number of ITP patients undergoing splenectomy has been on the decline and largely attributable to the newer and more effective second-line therapies. There is no pre-surgery variable predicting the ORR after splenectomy.

CONCLUSION

Splenectomy in ITP offers a long-term sustained response at an economical cost.

Risk factors of hospitalisation for thrombosis in adults with primary immune thrombocytopenia, including disease-specific treatments: a French nationwide cohort study

We aimed to assess the risk factors of venous thrombosis (VT) and arterial thrombosis (AT) in adults with primary immune thrombocytopenia (ITP), particularly in relation to treatments. The population comprised all incident primary ITP adults in France between 2009 and 2017 (FAITH cohort; NCT03429660) built in the national health database. Outcomes were the first hospitalisation for VT and AT. Multivariable Cox regression models included baseline risk factors, time-varying exposure to ITP drugs, splenectomy and to cardiovascular drugs. The cohort included 10 039 patients. A higher risk of hospitalisation for VT was observed with older age, history of VT, history of cancer, splenectomy [hazard ratio (HR) 3·23, 95% confidence interval (CI) 2·26-4·61], exposure to corticosteroids (HR 3·55, 95% CI 2·74-4·58), thrombopoietin-receptor agonists (TPO-RAs; HR 2·28, 95% CI 1·59-3·26) and intravenous immunoglobulin (IVIg; HR 2·10, 95% CI 1·43-3·06). A higher risk of hospitalisation for AT was observed with older age, male sex, a history of cardiovascular disease, splenectomy (HR 1·50, 95% CI 1·12-2·03), exposure to IVIg (HR 1·85, 95% CI 1·36-2·52) and TPO-RAs (HR 1·64, 95% CI 1·26-2·13). Rituximab was not associated with an increased risk. These findings help to estimate the risk of thrombosis in adult patients with ITP and to select treatment.

Immune Thrombocytopenia: Recent Advances in Pathogenesis and Treatments

Immune thrombocytopenia (ITP) is a rare autoimmune disease due to both a peripheral destruction of platelets and an inappropriate bone marrow production. Although the primary triggering factors of ITP remain unknown, a loss of immune tolerance-mostly represented by a regulatory T-cell defect-allows T follicular helper cells to stimulate autoreactive splenic B cells that differentiate into antiplatelet antibody-producing plasma cells. Glycoprotein IIb/IIIa is the main target of antiplatelet antibodies leading to platelet phagocytosis by splenic macrophages, through interactions with Fc gamma receptors (FcγRs) and complement receptors. This allows macrophages to activate autoreactive T cells by their antigen-presenting functions. Moreover, the activation of the classical complement pathway participates to platelet opsonization and also to their destruction by complement-dependent cytotoxicity. Platelet destruction is also mediated by a FcγR-independent pathway, involving platelet desialylation that favors their binding to the Ashwell-Morell receptor and their clearance in the liver. Cytotoxic T cells also contribute to ITP pathogenesis by mediating cytotoxicity against megakaryocytes and peripheral platelets. The deficient megakaryopoiesis resulting from both the humoral and the cytotoxic immune responses is sustained by inappropriate levels of thrombopoietin, the major growth factor of megakaryocytes. The better understanding of ITP pathogenesis has provided important therapeutic advances. B cell-targeting therapies and thrombopoietin-receptor agonists (TPO-RAs) have been used for years. New emerging therapeutic strategies that inhibit FcγR signaling, the neonatal Fc receptor or the classical complement pathway, will deeply modify the management of ITP in the near future.

Emerging Therapies in Immune Thrombocytopenia

Immune thrombocytopenia (ITP) is a rare autoimmune disorder caused by peripheral platelet destruction and inappropriate bone marrow production. The management of ITP is based on the utilization of steroids, intravenous immunoglobulins, rituximab, thrombopoietin receptor agonists (TPO-RAs), immunosuppressants and splenectomy. Recent advances in the understanding of its pathogenesis have opened new fields of therapeutic interventions. The phagocytosis of platelets by splenic macrophages could be inhibited by spleen tyrosine kinase (Syk) or Bruton tyrosine kinase (BTK) inhibitors. The clearance of antiplatelet antibodies could be accelerated by blocking the neonatal Fc receptor (FcRn), while new strategies targeting B cells and/or plasma cells could improve the reduction of pathogenic autoantibodies. The inhibition of the classical complement pathway that participates in platelet destruction also represents a new target. Platelet desialylation has emerged as a new mechanism of platelet destruction in ITP, and the inhibition of neuraminidase could dampen this phenomenon. T cells that support the autoimmune B cell response also represent an interesting target. Beyond the inhibition of the autoimmune response, new TPO-RAs that stimulate platelet production have been developed. The upcoming challenges will be the determination of predictive factors of response to treatments at a patient scale to optimize their management.

Immunization coverage among asplenic patients and strategies to increase vaccination compliance: a systematic review and meta-analysis

BACKGROUND

Asplenic or splenectomized patients have a higher risk (ranging from 10 to 50-fold) than the general population of developing an overwhelming post-splenectomy infection (OPSI). Thus, they should receive specific vaccinations to prevent bacterial infections and influenza. The aim of this meta-analysis was to estimate vaccination coverage (VC) with the recommended vaccines among splenectomized patients; strategies recommended in those studies to improve VC worldwide are considered as well.

RESEARCH DESIGN AND METHODS

Scopus, MEDLINE/PubMed, Google Scholar and ISI Web of Knowledge databases were searched. Research papers, short reports, reviews, and meta-analyses published between January 1, 2010 and July 18, 2020 were included; no geographic restrictions were included. Twenty-four studies were included in the meta-analysis.

RESULTS

For anti-pneumococcal vaccination, coverage was 55.1% (95%CI = 41.0-69.2%), for anti-Hib 48.3% (95%CI = 34.3-52.3%), for anti-meningococcal C/ACYW135 33.7% (95%CI = 23.6-43.9%), for anti-meningococcal B 13.3% (95%CI = 7.0-19.5%) and for anti-influenza 53.2% (95%CI = 22.0-84.4%). Most studies determined a lack of adherence to international guidelines by healthcare workers and suggested the need to better educate health professionals in the management of post-splenectomy patients.

CONCLUSIONS

The meta-analysis showed the suboptimal immunization coverage for the vaccines recommended for asplenic patients. Greater efforts must be made by public health professionals to increase VC in this group of patients at risk. Introducing specific prophylaxis protocols in the clinical routine seems to guarantee better immunization compliance in those patients.

A risk score for predicting hospitalization for community-acquired pneumonia in ITP using nationally representative data

Infection is one of the primary causes of death from immune thrombocytopenia (ITP), and the lungs are the most common site of infection. We identified the factors associated with hospitalization for community-acquired pneumonia (CAP) in nonsplenectomized adults with ITP and established the [corrected] (ACPA) prediction model to predict the incidence of hospitalization for CAP. This was a retrospective study of nonsplenectomized adult patients with ITP from 10 large medical centers in China. The derivation cohort included 145 ITP inpatients with CAP and 1360 inpatients without CAP from 5 medical centers, and the validation cohort included the remaining 63 ITP inpatients with CAP and 526 inpatients without CAP from the other 5 centers. The 4-item ACPA model, which included age, Charlson Comorbidity Index score, initial platelet count, and initial absolute lymphocyte count, was established by multivariable analysis of the derivation cohort. Internal and external validation were conducted to assess the performance of the model. The ACPA model had an area under the curve of 0.853 (95% confidence interval [CI], 0.818-0.889) in the derivation cohort and 0.862 (95% CI, 0.807-0.916) in the validation cohort, which indicated the good discrimination power of the model. Calibration plots showed high agreement between the estimated and observed probabilities. Decision curve analysis indicated that ITP patients could benefit from the clinical application of the ACPA model. To summarize, the ACPA model was developed and validated to predict the occurrence of hospitalization for CAP, which might help identify ITP patients with a high risk of hospitalization for CAP.

[Secondary ITP in adults]

Secondary forms of immune thrombocytopenia (ITP) represent approximately 20% of all ITP cases in adulthood and this rate increases with age. Since some causes may influence both the prognosis and outcome but also the management of ITP, a minimal workup must be performed at ITP diagnosis to look for an associated or underlying cause. Among adults, B-cell lymphomas and mainly chronic lymphocytic leukemia, systemic auto-immune diseases such as systemic lupus or primary immunodeficiencies mainly represented by common variable immunodeficiency are the most frequent causes of secondary ITP. Whereas first-line therapy used for secondary ITP is usually similar to the one commonly used in primary ITP and relies mostly on corticosteroids±intravenous immunoglobulin according to the severity of bleeding, second and third-line treatments must take into account the type and degree of activity of the underlying disease.

New insights into the epidemiology of immune thrombocytopenia in adult patients: Impact for clinical practice

New insights into immune thrombocytopenia (ITP) epidemiology in adult patients highlight three main outcomes of morbidity and mortality: bleeding, infection and thrombosis. This review depicts current evidence about incidence and risk factors of bleeding, infection and thrombosis as well as predictors of chronicity, and shows how this assessment impacts the choice of ITP second-line treatment at the individual-level basis.

Should we prevent thrombosis related to intravenous immunoglobulin infusions with systematic anticoagulant prophylaxis?

Intravenous immunoglobulins (IVIg) are commonly used for treatment of dysimmune diseases, but they are known to promote thrombotic events. The medical records of patients who received IVIg infusions to treat neuromuscular disorders were retrospectively studied during two periods: the on-demand period (May 2013-January 2015), when patients received anticoagulant prophylaxis based on personal thrombotic risk factors, and the systematic period (May 2015-January 2017), when patients received systematic anticoagulant prophylaxis. Of the 334 total patients included, 19/153 received anticoagulant prophylaxis in the on-demand period, and 181 were treated in the systematic period. In the on-demand period, thrombosis occurred in three patients (1.96%) as one central retinal artery occlusion, one pulmonary embolism, and one brachiocephalic vein thrombosis. In the systematic period, thrombosis occurred in two patients (1.1%), both as pulmonary embolisms. There was no statistical difference in thrombosis incidence between the periods (P=0.66). The only factor associated with thrombosis was splenectomy (20% versus 0.3% in patients without thrombosis, P=0.03). There were no adverse events due to thromboprophylaxis by low-molecular-weight heparin in either period. Systematic thromboprophylaxis did not significantly reduce the incidence of thrombosis versus thromboprophylaxis based on personal thrombotic risk.

Complications in the adult asplenic patient: A review for the emergency clinician

BACKGROUND

The spleen performs several important physiologic functions. However, patients can have functional asplenia or have their spleen removed for a number of reasons, which can put them at risk for several dangerous complications.

OBJECTIVE

This narrative review provides a focused evaluation of adult asplenic patients and complications in the emergency departing setting.

DISCUSSION

The spleen plays integral roles in the immune and reticuloendothelial systems and also modulates the inflammatory and coagulation cascades. Asplenia refers to the anatomic or physiologic loss of splenic function, which may be due to trauma, immunological, hematological, or oncological etiologies. Asplenic patients are at risk for several complications including infection, arterial and venous thrombosis, and pulmonary hypertension. Fever in an asplenic patient and overwhelming post-splenectomy infection (OPSI) are medical emergencies with a high mortality and require rapid evaluation and management with broad-spectrum antibiotics. Asplenic patients are at increased risk of arterial thrombosis, such as coronary artery disease, and venous thrombosis including deep venous thrombosis, pulmonary embolism, and splenic and portal vein thrombosis. Management of venous thrombosis includes anticoagulation. Pulmonary hypertension with associated right ventricular dysfunction may also occur in asplenia. These patients require hemodynamic stabilization with an emphasis on inciting causes and treatment of the pulmonary hypertension.

CONCLUSIONS

The spleen is an integral organ involved in several physiologic functions. Asplenia, or absence of spleen function, is associated with severe complications. Knowledge of these complications can improve the care of these patients.

Long-term safety and efficacy of rituximab in 248 adults with immune thrombocytopenia: Results at 5 years from the French prospective registry ITP-ritux

Rituximab is a second-line option in adults with immune thrombocytopenia (ITP), but the estimated 5-year response rate, only based on pooled retrospective data, is about 20%, and no studies have focused on long-term safety. We conducted a prospective multicenter registry of 248 adults with ITP treated with rituximab with 5 years of follow-up to assess its long-term safety and efficacy. The median follow-up was 68.4 [53.7-78.5] months. The incidence of severe infections was only 2/100 patient-years. Profound hypogammaglobulinemia (<5 g/L) developed in five patients at 15 to 31 months after the last rituximab infusion. In total, 25 patients died at a median age of 80 [69.5-83.9] years, corresponding to a mortality rate of 2.3/100 patient-years. Only three deaths related to infection that occurred 12 to 14 months after rituximab infusions could be due in part to rituximab. At 60 months of follow-up, 73 (29.4%) patients had a sustained response. On univariate and multivariate analysis, the only factor significantly associated with sustained response was a previous transient response to corticosteroids (P = .022). Overall, 24 patients with an initial response and then relapse received retreatment with rituximab, which gave a response in 92%, with a higher duration of response in 54%. As a result of its safety profile and its sustained response rate, rituximab remains an important option in the current therapeutic armamentarium for adult ITP. Retreatment could be an effective and safe option.

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.

Platelet activation and neutrophil extracellular trap (NET) formation in immune thrombocytopenia: is there an association?

No biological predictors for the increased risk of thrombosis in patients with immune thrombocytopenia (ITP) have been identified. The aim of the study was to investigate platelet and neutrophil activation as well neutrophil extracellular trap (NET) formation in 63 ITP patients and 30 healthy volunteers. Platelet and neutrophil activation was assessed during steady state using flow cytometry analysis, and NETs were evaluated by quantitation of cell free DNA (cfDNA), and citrullinated histone-3-DNA (CitH3-DNA). Patient platelets and neutrophils showed increased CD62 and CD11b expression compared to controls (p = .038, and p = .022, respectively). In patients, platelet activation inversely correlated with platelet count and platelet size (p < .001), and positively correlated with neutrophil degranulation (p = .024). More NET formation, both CitH3-DNA (p = .025) and cfDNA(p < .001), were present in ITP patients compared to controls. CitH3-DNA inversely correlated with CD62 expression on platelets (p = .042), but higher levels of cfDNA were observed in individuals with classical cardiovascular risk factors for thrombosis, and in those with a previous history of thrombotic events. In this disease, the increased platelet activation and plasma NET levels seem to be separable processes that associate (either positively or inversely in the case of CitH3-DNA or platelet degranulation, respectively) to platelet mass.

Mechanisms and therapeutic prospects of thrombopoietin receptor agonists

The second-generation thrombopoietin (TPO) receptor agonists eltrombopag and romiplostim are potent activators of megakaryopoiesis and represent a growing treatment option for patients with thrombocytopenic hematological disorders. Both TPO receptor agonists have been approved worldwide for the treatment of children and adults with chronic immune thrombocytopenia. In the EU and USA, eltrombopag is approved for the treatment of patients with severe aplastic anemia who have had an insufficient response to immunosuppressive therapy and in the USA for the first-line treatment of severe aplastic anemia in combination with immunosuppressive therapy. Eltrombopag has also shown efficacy in several other disease settings, for example, chemotherapy-induced thrombocytopenia, selected inherited thrombocytopenias, and myelodysplastic syndromes. While both TPO receptor agonists stimulate TPO receptor signaling and enhance megakaryopoiesis, their vastly different biochemical structures bestow upon them markedly different molecular and functional properties. Here, we review and discuss results from preclinical and clinical studies on the functional and molecular mechanisms of action of this new class of drug.

Evans syndrome in adults - incidence, prevalence, and survival in a nationwide cohort

Patients with Evans syndrome have both immune thrombocytopenia and autoimmune hemolytic anemia, but little is known about the epidemiology of this rare syndrome. Evans syndrome can be primary or secondary. This nationwide retrospective study linked health registries to identify 242 patients with Evans syndrome in Denmark in 1977-2017. For comparison, we identified three age-matched and sex-matched cohorts of patients with only immune thrombocytopenia or only autoimmune hemolytic anemia, and a general population cohort. The Evans syndrome cohort had a mean age of 58.5 years at diagnosis, 51.2% were women, and 27.3% were classified as secondary Evans syndrome. The annual Evans syndrome incidence and prevalence rose significantly during the study period, to 1.8 per million person-years and 21.3 per million persons, respectively, in 2016. The median survival with Evans syndrome was 7.2 years (primary Evans syndrome: 10.9 years; secondary Evans syndrome: 1.7 years). Secondary Evans syndrome was associated with higher mortality rates than any of the other cohorts, with a 5-year survival of 38%. Among patients with Evans syndrome, the prevailing causes of death were bleeding, infections, and hematological cancer. In conclusion, we found that both primary and secondary Evans syndrome conferred a poor prognosis. Lethal complications probably derive primarily from manifestations of underlying autoimmune hemolytic anemia and immune thrombocytopenia. Our findings suggested that suspicion of Evans syndrome should prompt vigilant clinical follow-up. International collaborations are warranted to advance our knowledge of optimal management of this rare disease.

Management of Adult Patients with Primary Immune Thrombocytopenia (ITP) in Clinical Practice: A Consensus Approach of the Spanish ITP Expert Group

Background and Objective

Diagnosis and management of primary immune thrombocytopenia (ITP) have changed dramatically in the last decade. The aim of the study was to obtain information about the opinion of the Spanish ITP Group (GEPTI) members regarding the best clinical practices for diagnosis and management of adult patients with ITP.

Materials and Methods

A two-round Delphi method was carried out by sending to 129 experts a 90-item questionnaire developed by 11 specialists, with a 4-point Likert scale (“never,” “sometimes,” “frequently,” and “always”) for the assessment of responses.

Results

Forty out of the 129 experts participated in the survey (participation rate 30.2%) and 39 completed the questionnaire (response rate 97.5%). Salient consensus points included the following: the need to indicate workup studies from a sustained platelet count < 100 x 10⁹/L in the absence of a clear etiology; bone marrow aspiration in elderly patients with suspected ITP; beginning treatment in asymptomatic patients with a platelet count < 20 x 10⁹/L; not exceeding 6-7 weeks of corticosteroid therapy; switching from corticosteroids to one thrombopoietin receptor agonist (TRA); switching to other TRA or other options as combinations of them with immunosuppressive drugs in case of failure; how to reduce tapering TRA; treating patients with symptomatic persistent ITP and platelet count > 20 x 10⁹/L; and considering mucosal or severe bleeding as a basic criterion for hospital admission.

Conclusions

The present consensus document provides a reference framework for the management of patients with ITP in clinical practice.

Cardiovascular and bleeding outcomes in a population-based cohort of patients with chronic immune thrombocytopenia

Essentials Immune thrombocytopenia (ITP) is an autoimmune disorder characterized by low platelet count. We conducted a cohort study of 3 584 chronic ITP patients from the Nordic countries. Cardiovascular events occurred across all platelet count levels. Cardiovascular or bleeding events were strong prognostic factors for all-cause mortality. Background Among patients with chronic immune thrombocytopenia (cITP), little is known regarding risk factors for cardiovascular and bleeding outcomes and how these events influence mortality. Objectives We examined the rate of cardiovascular events and bleeding requiring a hospital contact according to platelet count levels, as well as the prognostic impact of these events on all-cause mortality in adult patients with cITP. Methods We identified all cITP patients registered in the Nordic Country Patient Registry for Romiplostim during 1996 to 2015. Absolute risks and hazard ratios across platelet count levels based on Cox regression analysis were computed, adjusting for age, sex, prevalent/incident cITP, smoking, and comorbidities. We also compared all-cause mortality rates in cITP patients with and without cardiovascular and bleeding events. Results Among 3 584 cITP patients, 1-year risks were 1.9% for arterial cardiovascular events, 1.2% for venous thromboembolism, and 7.5% for bleeding. Rates of cardiovascular events were similar across platelet counts. Patients with platelet counts <50 × 109 /L had >2-fold higher rates of bleeding than patients with normal platelet counts. These associations were unchanged in time-varying analyses that considered changes in platelet counts during follow-up. Occurrences of cardiovascular and bleeding events were associated with 4-fold to 5-fold increases in 1-year mortality. Conclusions Among patients with cITP, the 1-year risks of cardiovascular events were 1% to 2%, while nearly 8% experienced a bleeding event within 1 year. Cardiovascular events occurred across all platelet levels, while low platelet counts were associated with increased hazards of bleeding. Cardiovascular and bleeding events were strong prognostic factors for mortality.

Switching thrombopoietin receptor agonist treatments in patients with primary immune thrombocytopenia

Primary immune thrombocytopenia (ITP) is a bleeding disorder that conventionally has been treated with steroids or other immunosuppressive treatments. The introduction of thrombopoietin receptor agonists (TPO-RAs), which increase platelet production, dramatically changed the treatment landscape for ITP by providing patients with well-tolerated, long-term treatment options. Two TPO-RAs, eltrombopag and romiplostim, have been approved in the United States and European Union for the treatment of ITP. Some patients do not benefit from the first TPO-RA they receive, so it is assumed that the alternate TPO-RA would have the same outcome. However, eltrombopag and romiplostim have distinct pharmacodynamic and pharmacokinetic properties and may have different tolerability and efficacy in individual patients with ITP. Published retrospective studies showed that >75% of patients who switched to the alternate TPO-RA maintained or achieved a response with the new treatment. Notably, most patients who switched due to lack of efficacy with the first TPO-RA responded to the alternate TPO-RA, which demonstrates an absence of cross-resistance between the two drugs. Therefore, switching to the alternate TPO-RA if the first TPO-RA fails to demonstrate a response should be considered before the use of a less-preferable option.

Prognostic Factors for Immune Thrombocytopenic Purpura Remission after Laparoscopic Splenectomy: A Cohort Study

Background and Objectives: Laparoscopic splenectomy (LS) has become the gold standard for patients with immune thrombocytopenic purpura (ITP). The total remission rate after splenectomy is 70%–90%, of which 66% is long-term. Despite this high response rate, some patients do not benefit from surgery. It is therefore important to try to identify risk factors for an unsatisfactory clinical response. The aim of this study was to assess long-term outcomes of LS for ITP and identify factors associated with increased disease remission rates. Materials and Methods: We retrospectively studied consecutive patients with ITP undergoing LS in a tertiary referral surgical center prospectively recorded in a database. Inclusion criteria were: Elective, laparoscopic splenectomy for diagnosed ITP, and complete follow-up. The cohort was divided into two groups—Group 1 (G1) patients with ITP remission after splenectomy and Group 2 (G2) patients without remission. There were 113 G1 patients and 52 G2 patients. Median follow-up was 9.5 (IQR: 5–15) years. Results: In univariate analysis, patient’s age, body mass index (BMI), preoperative platelet count, the need for platelet transfusions, and presence of hemorrhagic diathesis were shown to be statistically significant factors. Next, we built a multivariate logistic regression model using factors significant in univariate analysis. Age <41 years (odds ratio (OR) 4.49; 95% CI: 1.66–12.09), BMI < 24.3 kg/m² (OR: 4.67; 95% CI: 1.44–15.16), and preoperative platelet count ≥97 × 10³/mm³ (OR: 3.50; 95% CI: 1.30–9.47) were shown to be independent prognostic factors for ITP remission after LS. Conclusions: The independent prognostic factors for ITP remission after LS revealed in our study are: age <41 years, BMI < 2 4.3 kg/m², and preoperative platelet count ≥97 × 10³/mm³. Duration of the ITP and the time of treatment are not related to remission after LS.

Advances in chemical pharmacotherapy for the treatment of pediatric immune thrombocytopenia

INTRODUCTION

Immune thrombocytopenia (ITP) is an autoimmune bleeding disorder of heterogeneous pathophysiological mechanisms. Treatment endpoints include elevation of platelets and reduction of bleeding risk, elevation of quality of life, reduction of concomitant therapies and prevention from bleeding. Persistent and chronic ITP is more common in adults but occurs in children. Standard therapies include corticosteroids and immunoglobulins, both associated with side effects. There are new treatments, such as thrombopoietin-receptor agonists and promising investigational drugs.

AREAS COVERED

Experience from the management of adults is valuable for children with persistent and chronic symptomatic ITP. In this review first- and second-line therapies, but also investigational drugs for children with ITP are discussed.

EXPERT OPINION

Although time-consuming and based on experience, children with no or mild bleeding can be safely managed with a watch and wait strategy. Chronic symptomatic immune thrombocytopenia is an area of second-line treatments based on a highly individualized approach. Furthermore, there are investigational drugs, which may also be of benefit for children with chronic symptomatic ITP.

Clinical spectrum of pyruvate kinase deficiency: data from the Pyruvate Kinase Deficiency Natural History Study

An international, multicenter registry was established to collect retrospective and prospective clinical data on patients with pyruvate kinase (PK) deficiency, the most common glycolytic defect causing congenital nonspherocytic hemolytic anemia. Medical history and laboratory and radiologic data were retrospectively collected at enrollment for 254 patients with molecularly confirmed PK deficiency. Perinatal complications were common, including anemia that required transfusions, hyperbilirubinemia, hydrops, and prematurity. Nearly all newborns were treated with phototherapy (93%), and many were treated with exchange transfusions (46%). Children age 5 years and younger were often transfused until splenectomy. Splenectomy (150 [59%] of 254 patients) was associated with a median increase in hemoglobin of 1.6 g/dL and a decreased transfusion burden in 90% of patients. Predictors of a response to splenectomy included higher presplenectomy hemoglobin (P = .007), lower indirect bilirubin (P = .005), and missense PKLR mutations (P = .0017). Postsplenectomy thrombosis was reported in 11% of patients. The most frequent complications included iron overload (48%) and gallstones (45%), but other complications such as aplastic crises, osteopenia/bone fragility, extramedullary hematopoiesis, postsplenectomy sepsis, pulmonary hypertension, and leg ulcers were not uncommon. Overall, 87 (34%) of 254 patients had both a splenectomy and cholecystectomy. In those who had a splenectomy without simultaneous cholecystectomy, 48% later required a cholecystectomy. Although the risk of complications increases with severity of anemia and a genotype-phenotype relationship was observed, complications were common in all patients with PK deficiency. Diagnostic testing for PK deficiency should be considered in patients with apparent congenital hemolytic anemia and close monitoring for iron overload, gallstones, and other complications is needed regardless of baseline hemoglobin. This trial was registered at www.clinicaltrials.gov as #NCT02053480.

Commensal Microbes Induce Serum IgA Responses that Protect against Polymicrobial Sepsis

Serum immunoglobulin A (IgA) antibodies are readily detected in mice and people, but the mechanisms underlying the induction of serum IgA and its role in host protection remain uncertain. We report that select commensal bacteria induce several facets of systemic IgA-mediated immunity. Exposing conventional mice to a unique but natural microflora that included several members of the Proteobacteria phylum led to T cell-dependent increases in serum IgA levels and the induction of large numbers of IgA-secreting plasma cells in the bone marrow. The resulting serum IgA bound to a restricted collection of bacterial taxa, and antigen-specific serum IgA antibodies were readily induced after intestinal colonization with the commensal bacterium Helicobacter muridarum. Finally, movement to a Proteobacteria-rich microbiota led to serum IgA-mediated resistance to polymicrobial sepsis. We conclude that commensal microbes overtly influence the serum IgA repertoire, resulting in constitutive protection against bacterial sepsis.