Profound symptomatic hypogammaglobulinemia: a rare late complication after rituximab treatment for immune thrombocytopenia. Report of 3 cases and systematic review of the literature

Severe enterovirus infections in patients with immune-mediated inflammatory diseases receiving anti-CD20 monoclonal antibodies

OBJECTIVE

Patients with X linked agammaglobulinemia are susceptible to enterovirus (EV) infections. Similarly, severe EV infections have been described in patients with impaired B-cell response following treatment with anti-CD20 monoclonal antibodies (mAbs), mostly in those treated for haematological malignancies. We aimed to describe severe EV infections in patients receiving anti-CD20 mAbs for immune-mediated inflammatory diseases (IMIDs).

METHODS

Patients were included following a screening of data collected through the routine surveillance of EV infections coordinated by the National Reference Center and a review of the literature. Additionally, neutralising antibodies were assessed in a patient with chronic EV-A71 meningoencephalitis.

RESULTS

Nine original and 17 previously published cases were retrieved. Meningoencephalitis (n=21/26, 81%) associated with EV-positive cerebrospinal fluid (n=20/22, 91%) was the most common manifestation. The mortality rate was high (27%). EV was the only causal agents in all reported cases. Patients received multiple anti-CD20 mAbs infusions (median 8 (5-10)), resulting in complete B-cell depletion and moderate hypogammaglobulinemia (median 4.9 g/L (4.3-6.7)), and had limited concomitant immunosuppressive treatments. Finally, in a patient with EV-A71 meningoencephalitis, a lack of B-cell response to EV was shown.

CONCLUSION

EV infection should be evoked in patients with IMIDs presenting with atypical organ involvement, especially meningoencephalitis. Anti-CD20 mAbs may lead to impaired B-cell response against EV, although an underlying primary immunodeficiency should systematically be discussed.

Rituximab De-escalation in Patients With Neuromyelitis Optica Spectrum Disorder

BACKGROUND AND OBJECTIVES

Exit strategies such as de-escalations have not been evaluated for rituximab in patients with neuromyelitis optica spectrum disorder (NMOSD). We hypothesized that they are associated with disease reactivations and aimed to estimate this risk.

METHODS

We describe a case series of real-world de-escalations from the French NMOSD registry (NOMADMUS). All patients met the 2015 International Panel for NMO Diagnosis (IPND) diagnostic criteria for NMOSD. A computerized screening of the registry extracted patients with rituximab de-escalations and at least 12 months of subsequent follow-up. We searched for 7 de-escalation regimens: scheduled discontinuations or switches to an oral treatment after single infusion cycles, scheduled discontinuations or switches to an oral treatment after periodic infusions, de-escalations before pregnancies, de-escalations after tolerance issues, and increased infusion intervals. Rituximab discontinuations motivated by inefficacy or for unknown purposes were excluded. The primary outcome was the absolute risk of NMOSD reactivation (one or more relapses) at 12 months. AQP4+ and AQP4- serotypes were analyzed separately.

RESULTS

We identified 137 rituximab de-escalations between 2006 and 2019 that corresponded to a predefined group: 13 discontinuations after a single infusion cycle, 6 switches to an oral treatment after a single infusion cycle, 9 discontinuations after periodic infusions, 5 switches to an oral treatment after periodic infusions, 4 de-escalations before pregnancies, 9 de-escalations after tolerance issues, and 91 increased infusion intervals. No group remained relapse-free over the whole de-escalation follow-up (mean: 3.2 years; range: 0.79-9.5), except pregnancies in AQP+ patients. In all groups combined and within 12 months, reactivations occurred after 11/119 de-escalations in patients with AQP4+ NMOSD (9.2%, 95% CI [4.7-15.9]), from 0.69 to 10.0 months, and in 5/18 de-escalations in patients with AQP4- NMOSD (27.8%, 95% CI [9.7-53.5]), from 1.1 to 9.9 months.

DISCUSSION

There is a risk of NMOSD reactivation whatever the rituximab de-escalation regimen.

TRIAL REGISTRATION INFORMATION

Registered on ClinicalTrials.gov: NCT02850705.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that de-escalation of rituximab increases the probability of disease reactivation.

Hypogammaglobulinemia, late-onset neutropenia, and infections following rituximab

Rituximab is a chimeric anti-CD20 monoclonal antibody that targets CD20-expressing B lymphocytes, has a well-defined efficacy and safety profile, and is broadly used to treat a wide array of diseases. In this review, we cover the mechanism of action of rituximab and focus on hypogammaglobulinemia and late-onset neutropenia-2 immune effects secondary to rituximab-and subsequent infection. We review risk factors and highlight key considerations for immunologic monitoring and clinical management of rituximab-induced secondary immune deficiencies. In patients treated with rituximab, monitoring for hypogammaglobulinemia and infections may help to identify the subset of patients at high risk for developing poor B cell reconstitution, subsequent infections, and adverse complications. These patients may benefit from early interventions such as vaccination, antibacterial prophylaxis, and immunoglobulin replacement therapy. Systematic evaluation of immunoglobulin levels and peripheral B cell counts by flow cytometry, both at baseline and periodically after therapy, is recommended for monitoring. In addition, in those patients with prolonged hypogammaglobulinemia and increased infections after rituximab use, immunologic evaluation for inborn errors of immunity may be warranted to further risk stratification, increase monitoring, and assist in therapeutic decision-making. As the immunologic effects of rituximab are further elucidated, personalized approaches to minimize the risk of adverse reactions while maximizing benefit will allow for improved care of patients with decreased morbidity and mortality.

[Management of hypogammaglobulinemia]

Hypogammaglobulinemia (hypoγ) is defined as a serum IgG level < 7 g/L. It is most often detected on serum protein electrophoresis. Given the existence of transient hypoγ, its persistence should be checked at distance, preferably by requesting a blood test for IgG, IgA and IgM, which will be needed to characterize a possible primary immune deficiency (PID). In the case of association with a monoclonal component, the first step is to look for a cryoglobulin causing a false hypoγ. Otherwise, the etiological investigation is dictated by the clinical examination. For example, the notion of chronic diarrhea should lead to a search for an enteropathy causing a digestive loss of gammaglobulins (an ambiguous situation because some DIP can be complicated by an enteropathy). In the absence of an obvious explanation, a secondary cause must first be ruled out (secondary immune deficiencies are 30 times more common than PID). The first simple test to perform is 24-hour proteinuria, coupled with urinary protein electrophoresis, to rule out 2 diagnoses: nephrotic syndrome and light chain myeloma. Subsequently, blood immunophenotyping looking for a circulating B clone is recommended, allowing the investigations to be directed towards a lymphoid hemopathy. Drug-induced hypoγ may also be suspected if certain drugs such as corticosteroids, anti-epileptics or immunosuppressive agents (especially anti-CD20) are taken. The profile of a drug-induced hypoγ is different from that of a DIP: it is rarely profound, the IgA level is preserved and there is no deficit in switched memory B lymphocytes. Finally, a thoracoabdominal CT-scan will help to rule out a thymoma and identify a deep tumor syndrome. If all these tests are normal, a PID is suspected, the leader of which in adults remains the common variable immunodeficiency, which is the most frequent symptomatic PID in adults.

Lymphoma as an Exclusion Criteria for CVID Diagnosis Revisited

PURPOSE

Hypogammaglobulinemia in a context of lymphoma is usually considered as secondary and prior lymphoma remains an exclusion criterion for a common variable immunodeficiency (CVID) diagnosis. We hypothesized that lymphoma could be the revealing symptom of an underlying primary immunodeficiency (PID), challenging the distinction between primary and secondary hypogammaglobulinemia.

METHODS

Within a French cohort of adult patients with hypogammaglobulinemia, patients who developed a lymphoma either during follow-up or before the diagnosis of hypogammaglobulinemia were identified. These two chronology groups were then compared. For patients without previous genetic diagnosis, a targeted next-generation sequencing of 300 PID-associated genes was performed.

RESULTS

A total of forty-seven patients had developed 54 distinct lymphomas: non-Hodgkin B cell lymphoma (67%), Hodgkin lymphoma (26%), and T cell lymphoma (7%). In 25 patients, lymphoma developed prior to the diagnosis of hypogammaglobulinemia. In this group of patients, Hodgkin lymphoma was overrepresented compared to the group of patients in whom lymphoma occurred during follow-up (48% versus 9%), whereas MALT lymphoma was absent (0 versus 32%). Despite the histopathological differences, both groups presented with similar characteristics in terms of age at hypogammaglobulinemia diagnosis, consanguinity rate, or severe T cell defect. Overall, genetic analyses identified a molecular diagnosis in 10/47 patients (21%), distributed in both groups and without peculiar gene recurrence. Most of these patients presented with a late onset combined immunodeficiency (LOCID) phenotype.

CONCLUSION

Prior or concomitant lymphoma should not be used as an exclusion criteria for CVID diagnosis, and these patients should be investigated accordingly.

Secondary rituximab-associated versus primary immunodeficiencies: The enigmatic border

Rituximab (RTX), a chimeric monoclonal antibody targeting CD20-positive cells, is a valuable treatment option for malignant and benign immune-related disorders. The rationale of targeting the CD20 antigen relies on depletion of both healthy and autoreactive/malignant CD20-espressing cells, but normal B-cell reconstitution is expected within months after treatment. Nevertheless, a number of recent studies have documented prolonged B-cell deficiency associated with new-onset hypogammaglobulinemia in patients receiving RTX. Awareness of post-RTX hypogammaglobulinemia has become wider among clinicians, with a growing number of reports about the increased incidence, especially in children. Although these patients were previously regarded as affected by secondary/iatrogenic immunodeficiency, atypical clinical and immunological manifestations (e.g., severe or opportunistic infections; prolonged B-cell aplasia) raise concerns of delayed manifestations of genetic immunological disorders that have been unveiled by B-cell perturbation. As more patients with undiagnosed primary immune deficiency receiving RTX have been identified, it remains the challenge in discerning those that might display a higher risk of persistent RTX-associated hypogammaglobulinemia and need a tailored immunology follow-up. In this review, we summarize the principal evidence regarding post-RTX hypogammaglobulinemia and provide a guideline for identifying patients at higher risk of RTX-associated hypogammaglobulinemia that could harbor an inborn error of immunity.

Practical guidance for the diagnosis and management of secondary hypogammaglobulinemia: A Work Group Report of the AAAAI Primary Immunodeficiency and Altered Immune Response Committees

Secondary hypogammaglobulinemia (SHG) is characterized by reduced immunoglobulin levels due to acquired causes of decreased antibody production or increased antibody loss. Clarification regarding whether the hypogammaglobulinemia is secondary or primary is important because this has implications for evaluation and management. Prior receipt of immunosuppressive medications and/or presence of conditions associated with SHG development, including protein loss syndromes, are histories that raise suspicion for SHG. In patients with these histories, a thorough investigation of potential etiologies of SHG reviewed in this report is needed to devise an effective treatment plan focused on removal of iatrogenic causes (eg, discontinuation of an offending drug) or treatment of the underlying condition (eg, management of nephrotic syndrome). When iatrogenic causes cannot be removed or underlying conditions cannot be reversed, therapeutic options are not clearly delineated but include heightened monitoring for clinical infections, supportive antimicrobials, and in some cases, immunoglobulin replacement therapy. This report serves to summarize the existing literature regarding immunosuppressive medications and populations (autoimmune, neurologic, hematologic/oncologic, pulmonary, posttransplant, protein-losing) associated with SHG and highlights key areas for future investigation.

Case Report: Crossing a rugged road in a primary immune regulatory disorder

Over the last decades, Inborn Errors of Immunity (IEI) characterized by an immune dysregulatory picture, isolated or combined with infections, have been increasingly identified and referred as Primary Immune Regulatory Disorders (PIRD). PIRD diagnosis may be difficult due to heterogeneity of time onset, sequence of clinical manifestations and laboratory abnormalities. Moreover, the dissection of a PIRD vs. a secondary immunodeficiency (SID) might be a real challenge since the same indications for immunosuppressant treatments might represent per se a PIRD clinical expression. Here we report a female patient with a history of recurrent respiratory and urinary tract infections since early infancy and a diagnosis of Rheumatoid Arthritis in adulthood. After poor response to several biologicals she was treated with Rituximab and sent to immunology referral for a severe hypogammaglobulinemia. Clinical and immunological features matched a diagnosis of common variable immunodeficiency and when IgG replacement therapy and antibiotic prophylaxis were added a good infectious control was obtained. Next generation sequencing analysis has revealed a novel heterozygous VUS in the IKBKB gene (c.1465A > G; p.Ser489Gly). Functional analysis has shown a reduced capacity of B lymphocytes and CD4 positive T cells in inducing IκBα degradation, with negative impact on NF-kB pathway. Due to recurrent infections attributed to a common condition in childhood and to an exclusive autoimmunity-centered approach in adulthood, both diagnosis and suitable treatment strategies have suffered a significant delay. To reduce the diagnostic delay, pediatricians, general practitioners and specialists should be aware of IEI and the challenges to differentiate them from SID. Furthermore, genetic characterization and functional analysis may contribute to a personalized approach, in a perspective of targeted or semi-targeted therapy.

Case Report: Persistent Hypogammaglobulinemia More Than 10 Years After Rituximab Given Post-HSCT

Rituximab (RTX) is an anti-CD20 monoclonal antibody that targets B cells-from the immature pre-B-cell stage in the bone marrow to mature circulating B cells-while preserving stem cells and plasma cells. It is used to treat autoimmune diseases, hematological malignancies, or complications after hematopoietic stem cell transplantation (HSCT). Its safety profile is acceptable; however, a subset of patients can develop persistent hypogammaglobulinemia and associated severe complications, especially in pediatric populations. We report the unrelated cases of two young men aged 17 and 22, presenting with persistent hypogammaglobulinemia more than 7 and 10 years after treatment with RTX, respectively, and administered after HSCT for hemolytic anemia and Epstein-Barr virus reactivation, respectively. Both patients' immunological workups showed low levels of total immunoglobulin, vaccine antibodies, and class switched-memory B cells but an increase in naive B cells, which can also be observed in primary immunodeficiencies such as those making up common variable immunodeficiency. Whole exome sequencing for one of the patients failed to detect a pathogenic variant causing a Mendelian immunological disorder. Annual assessments involving interruption of immunoglobulin replacement therapy each summer failed to demonstrate the recovery of endogenous immunoglobulin production or normal numbers of class switched-memory B cells 7 and 10 years after the patients' respective treatments with RTX. Although the factors that may lead to prolonged hypogammaglobulinemia after rituximab treatment (if necessary) remain unclear, a comprehensive immunological workup before treatment and long-term follow-up are mandatory to assess long-term complications, especially in children.

Rituximab for recurrence of primary focal segmental glomerulosclerosis after kidney transplantation: Results of a nationwide study

Rituximab (RTX) therapy for primary focal segmental glomerulosclerosis recurrence after kidney transplantation (KT) has been extensively debated. We aimed to assess the benefit of adding RTX to plasmapheresis (PP), corticosteroids, and calcineurin inhibitors (standard of care, SOC). We identified 148 adult patients who received KT in 12/2004-12/2018 at 21 French centers: 109 received SOC (Group 1, G1), and 39 received immediate RTX along with SOC (Group 2, G2). In G1, RTX was introduced after 28 days of SOC in the event of failure (G1a, n = 19) or PP withdrawal (G1b, n = 12). Complete remission (CR) was achieved in 46.6% of patients, and partial remission (PR) was achieved in 33.1%. The 10-year graft survival rates were 64.7% and 17.9% in responders and nonresponders, respectively. Propensity score analysis showed no difference in CR+PR rates between G1 (82.6%) and G2 (71.8%) (p = .08). Following the addition of RTX (G1a), 26.3% of patients had CR, and 31.6% had PR. The incidence of severe infections was similar between patients treated with and without RTX. In multivariable analysis, infection episodes were associated with hypogammaglobulinemia <5 g/L. RTX could be used in cases of SOC failure or remission for early discontinuation of PP without increasing the risk of infection.

Dysfunctional Immune System Reconstitution After Rituximab Exposure In Utero

Rituximab is an antibody that binds to B-lymphocytes and is increasingly used during pregnancy. As an immunoglobulin G, it will transfer across the placenta. Previous case reports describe a diversity of clinical presentations in neonates born following rituximab exposure in utero. Our case is the first to offer the long-term experience in the care of an infant with severe neutropenia and prolonged profound hypogammaglobulinemia and class-switching B cell defect after in utero rituximab exposure.

[Common variable immunodeficiency disorders: Updated diagnostic criteria and genetics]

Common variable immunodeficiency disorders (CVID) are a heterogeneous group of conditions with hypogammaglobulinemia as the common denominator. These are the most common symptomatic primary immunodeficiency disorder in adults. Two different clinical forms are described: one group only develops infections, while a second includes (sometimes without infections, at least at the onset of disease course) a variety of non-infectious autoimmune, inflammatory, granulomatous and/or lymphoproliferative manifestations, sometimes revealing the disease and often observed in Internal Medicine. The international diagnostic criteria for CVID were updated in 2016 and are the subject of several comments in this general review. The recent use of new sequencing techniques makes it possible to better genetically define CVID. The identification of such a genetic disease makes it possible to treat pathophysiologically, in particular autoimmune and lymphoproliferative complications, with targeted treatments, sometimes used in other diseases. Determining a genetic disease in these patients also makes it possible to provide appropriate genetic counseling, and therefore to monitor mutated individuals, symptomatic or not.

Consensus Treatment Plans for Severe Pediatric Antineutrophil Cytoplasmic Antibody-Associated Vasculitis

OBJECTIVE

There is no standardized approach to the treatment of pediatric antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (ped-AAV). Because of the rarity of ped-AAV, randomized trials have not been feasible. The Childhood Arthritis and Rheumatology Research Alliance (CARRA) developed consensus treatment plans (CTPs) for severe ped-AAV to enable the future study of comparative effectiveness and safety.

METHODS

A workgroup of CARRA members (rheumatologists and nephrologists) formed the AAV working group. This group performed a literature review on existing evidence-based treatments and guidelines for the management of AAV. They determined that the target population for CTP development was patients <18 years with new-onset granulomatosis with polyangiitis (GPA), microscopic polyangiitis, or renal-limited AAV (eosinophilic-GPA was excluded) with presentation confined to those with severe disease i.e. organ- or life-threatening. Face-to-face consensus conferences employed nominal group techniques to identify treatment strategies for remission-induction and remission-maintenance, data elements to be systematically collected, and outcomes to be measured over time.

RESULTS

The ped-AAV workgroup developed two CTPs for each of the remission-induction and remission-maintenance of severe AAV. A corticosteroid-weaning regimen for induction and maintenance, a core dataset, and outcome measures were also defined. A random sample of CARRA membership voted acceptance of the CTPs for remission-induction and remission-maintenance with a 94% (75/80) and 98% (78/80) approval rate respectively.

CONCLUSION

Consensus methodology established standardized CTPs for treating severe ped-AAV. These CTPs were in principle accepted by CARRA-wide membership for pragmatic comparative effectiveness evaluation in a long-term registry.

Clinical and biological activity of rituximab in the treatment of pemphigus

B-cells are major effector cells in autoimmunity since they differentiate into plasmocytes that produce pathogenic auto-antibody such as anti-desmoglein antibodies in pemphigus patients. Major advances were obtained using whole B-cell depleting therapies including anti-CD20 antibodies in refractory pemphigus patients that lead to rituximab approval in pemphigus patients in EU and USA. This review summarizes the data supporting the efficacy of rituximab in pemphigus and provides an overview of the reported immunological changes underlying its therapeutic action. Short and long-term remission in pemphigus is explained by the removal of autoreactive B-cells involved in the production of pathogenic IgG auto-antibodies and by enhancement of the appearance of regulatory B-cells that could maintain long term immune tolerance.

Rituximab and eculizumab when treating nonmalignant hematologic disorders: infection risk, immunization recommendations, and antimicrobial prophylaxis needs

Rituximab and eculizumab, monoclonal antibodies that deplete most B cells and activate the terminal complement, respectively, are used to treat nonmalignant hematologic disorders (NMHDs), sometimes with unfavorable effects on the immune system. Hypogammaglobulinemia and neutropenia have been reported with variable prevalence in patients treated with rituximab. Neutropenia is mild and transient, and serious infectious complications are uncommon, so treatment is not indicated. Hypogammaglobulinemia is of greater concern. There is a lack of agreement on a standardized definition, and pre- and posttreatment immunoglobulin (Ig) levels are not routinely obtained. The association among low Ig levels, infectious risk, and mortality and morbidity in this population is unclear. There are also no formal guidelines on indication, risk factors, and threshold level of IgG to prompt Ig replacement therapy (IgRT). Among patients with NMHD, preexisting or persistent hypogammaglobulinemia (PH) after treatment with rituximab has been linked to underlying primary immunodeficiency disorders; therefore, a high index of suspicion should be maintained, and immunologic and genetic evaluation should be considered. Overall, important strategies in managing patients who are receiving rituximab include routine monitoring of pre- and posttreatment IgG levels, immune reconstitution (eg, B-cell subsets), assessment of vaccination status and optimization before treatment, and individualized consideration for IgRT. Accordingly, we discuss immunizations. Eculizumab, most commonly used in the treatment of paroxysmal nocturnal hemoglobinuria and atypical hemolytic uremic syndrome, poses increased risk of meningococcal infections. To decrease the risk of infection, a meningococcal vaccination series is recommended before initiating therapy, and prophylactic antibiotics are preferred during the course of treatment.

[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.

Rituximab and immune thrombocytopenia in adults: The state of knowledge 20 years later

Rituximab has been used for immune thrombocytopenia (ITP) for almost 20 years and is now considered a valid off-label second-line treatment. About 60% to 70% of patients with ITP show initial response to rituximab, but in half of these patients, the disease will eventually relapse. Therefore, in 30% of patients with persistent or chronic ITP, one course of rituximab at 375 mg/m²/week for 4 weeks or 2 fixed 1000-mg rituximab infusions allows for a sustained response rate at 5 years. Unfortunately, to date, no robust predictor of long-term sustained response has been found to assist the physician in deciding to treat with rituximab on an individual basis, and the choice of rituximab or another second-line treatment must be individualized and shared with the patient. Retreatment with rituximab has been found efficient, with a similar or higher magnitude and duration of response in most patients. Rituximab is usually well tolerated, with mainly mild and easily manageable infusion-related adverse events. Severe infections are uncommon, including in the long-term, and occur in patients with at least another contributing factor in more than two thirds. Several issues remain to be resolved. Indeed, head-to-head comparisons with other and new treatments in ITP and robust predictors of long-term response are urgently needed to better determine the position of rituximab in the therapeutic armamentarium for adult ITP. Additionally, the place of combination therapies, maintenance therapy with rituximab and rituximab in newly-diagnosed ITP deserve additional studies.

Impaired Immune Health in Survivors of Diffuse Large B-Cell Lymphoma

PURPOSE

Therapeutic advances for diffuse large B-cell lymphoma (DLBCL) have led to an increasing number of survivors. Both DLBCL and its treatments perturb the immune system, yet little is known about immune health during extended survivorship.

METHODS

In this retrospective cohort study, we compared 21,690 survivors of DLBCL from the California Cancer Registry (CCR) to survivors of breast, prostate, head and neck, and melanoma cancers. We linked their CCR records to a statewide database documenting hospital, emergency room, and ambulatory surgery visits and investigated the incidence of autoimmune conditions, immune deficiencies, and infections 1-10 years after cancer diagnosis.

RESULTS

We found elevated incidence rate ratios (IRRs) for many immune-related conditions in survivors of DLBCL compared with other cancer survivors, including significantly and consistently elevated IRRs for viral and fungal pneumonias (up to 10.8-fold), meningitis (up to 5.3-fold), as well as humoral deficiency (up to 17.6-fold) and autoimmune cytopenias (up to 12-fold). IRRs for most conditions remained high even in the late survivorship period (5-10 years after cancer diagnosis). The elevated risks could not be explained by exposure to chemotherapy, stem-cell transplantation, or rituximab, except for IRRs for humoral deficiency, which were consistently higher after the incorporation of rituximab into DLBCL treatments.

CONCLUSION

To our knowledge, this is the largest cohort study with extended follow-up to demonstrate impaired immune health in survivors of DLBCL. The observed persistent, elevated risks for autoimmune diseases, immune deficiencies, and infectious conditions may reflect persistent immune dysregulation caused by lymphoma or treatment and may lead to excess morbidity and mortality during survivorship. Improved understanding of these risks could meaningfully improve long-term care of patients with DLBCL.

Second-line treatment trends and long-term outcomes of 392 children with chronic immune thrombocytopenic purpura: the French experience over the past 25 years

Childhood chronic immune thrombocytopenic purpura (cITP) is a rare disease. In severe cases, there is no evidence for the optimal therapeutic strategy. Our aim was to describe the real-life management of non-selected children with cITP at diagnosis. Since 2004, patients less than 18 years old with cITP have been enrolled in the national prospective cohort, OBS'CEREVANCE. From 1990 to 2014, in 29 centres, 392 children were diagnosed with cITP. With a median follow-up of six years (2·0-25), 45% did not need second-line therapy, and 55% (n = 217) received one or more second lines, mainly splenectomy (n = 108), hydroxychloroquine (n = 61), rituximab (n = 61) or azathioprine (n = 40). The overall five-year further second-line treatment-free survival was 56% [95% CI 49·5-64.1]. The use of splenectomy significantly decreased over time. Hydroxychloroquine was administered to children with positive antinuclear antibodies, more frequently older and girls, and reached 55% efficacy. None of the patients died. Ten years after the initial diagnosis, 55% of the 56 followed children had achieved complete remission. Children with cITP do not need second-line treatments in 45% of cases. Basing the treatment decision on the pathophysiological pathways is challenging, as illustrated by ITP patients with positive antinuclear antibodies treated with hydroxychloroquine.

Fatal Hypogammaglobulinemia 3 Years after Rituximab in a Patient with Immune Thrombocytopenia: An Underlying Genetic Predisposition?

We report the case of a young woman who developed, 3 years after stopping Rituximab (RTX) prescribed for immune thrombocytopenia (ITP), a severe immunodeficiency leading to fatal pulmonary Epstein–Barr virus-positive diffuse large B-cell lymphoma. Genetic analysis led us to identify four missense mutations known to affect immune-deficiency–associated genes (FAS-ligand (FASL) gene (p.G167R); perforin-1 (PRF1 (p.R55C) gene; the Bloom syndrome RecQ-Like helicase (BLM) gene and the Moesin (MSN) (p.A122T) gene). The heterozygous mutation in the FASL gene, not present in the Genome Aggregation Database or ClinVar database, could suggest atypical Autoimmune LymphoProliferative Syndrome and its role in this patient's immunodepression is discussed. This observation strengthens the role of FASL gene mutation in severe clinical phenotypes of primary immune deficiency and raises new questions about the genetic background of ITP occurring in young people in a context of immunodeficiency.

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.

Rituximab Unveils Hypogammaglobulinemia and Immunodeficiency in Children with Autoimmune Cytopenia

BACKGROUND

Rituximab (RTX; anti-CD20 mAb) is a treatment option in children with refractory immune thrombocytopenia, autoimmune hemolytic anemia (AHA), and Evans syndrome (ES). Prevalence and clinical course of RTX-induced hypogammaglobulinemia in these patients are poorly known.

OBJECTIVE

To evaluate the prevalence and risk factors for persistent hypogammaglobulinemia (PH) after RTX use.

METHODS

Clinical and immunologic data from children treated with RTX for immune thrombocytopenia, AHA, and ES were collected from 16 Italian centers and 1 UK center at pre-RTX time point (0), +6 months, and yearly, up to 4 years post-RTX. Patients with previously diagnosed malignancy or primary immune deficiency (PID) were excluded.

RESULTS

We analyzed 53 children treated with RTX for immune thrombocytopenia (n = 36), AHA (n = 13), and ES (n = 4). Median follow-up was 30 months (range, 12-48). Thirty-two percent of patients (17 of 53) experienced PH, defined as IgG levels less than 2 SD for age at last follow-up (>12 months after RTX). Significantly delayed B-cell recovery was observed in children experiencing PH (hazard ratio, 0.55; P < .05), and 6 of 17 (35%) patients had unresolved B-cell lymphopenia at last follow-up. PH was associated with IgA and IgM deficiency, younger age at RTX use (51 vs 116 months; P < .01), a diagnosis of AHA/ES, and better response to RTX. Nine patients with PH (9 of 17 [53%]) were eventually diagnosed with a PID.

CONCLUSIONS

Post-RTX PH is a frequent condition in children with autoimmune cytopenia; a sizable proportion of patients with post-RTX PH were eventually diagnosed with a PID. In-depth investigation for PID is therefore recommended in these patients.

Secondary antibody deficiency in neurology

PURPOSE OF REVIEW

Induction of lymphocyte depletion is increasingly used as a therapeutic strategy for central and peripheral neuroinflammatory disease. However, there is also a growing recognition of the treatment-related complication of secondary antibody deficiency (SAD). Although the occurrence of hypogammaglobulinaemia is a recognized phenomenon during immunomodulation, robust data on the coexistence of impaired responses to immunization, and significant and/or atypical infections is scarce. Here we review the literature on SAD in anti-CD20 therapy.

RECENT FINDINGS

Several factors that may increase the incidence of SAD have now been identified, including low levels of immunoglobulins prior to the commencement of B-cell ablation therapy, duration of maintenance therapy, and concurrent or prior use of other immunosuppressing agents such as cyclophosphamide and steroids. Measurement of disease-specific antibodies and vaccine response are likely to be helpful adjuncts to measurement of serum immunoglobulin levels during B-cell depleting therapy. Supportive treatment may include amending the treatment schedule to limit cumulative dose.

SUMMARY

B-cell depleting agents offer considerable therapeutic benefit in neurology. We propose modifications in current practice that include risk stratification and early identification of SAD, with the aim of minimising morbidity and mortality related to this underappreciated condition.

Rituximab in the treatment of immune thrombocytopenia: what is the role of this agent in 2019?

The use of rituximab for the treatment of immune thrombocytopenia was greeted enthusiastically: it led to up to 60% response rates, making it, nearly 20 years ago, the main alternative to splenectomy, with far fewer side effects. However, long-term follow-up data showed that only 20-30% of patients maintained the remission. No significant changes have been registered using different dose schedules and timing of administration, while the combination with other drugs seemed promising. Higher response rates have been observed in young women before the chronic phase, but apart from that, other clinical factors or biomarkers predictive of response are still lacking. In this review we examine the historical and current role of rituximab in the management of immune thrombocytopenia, 20 years after its first use for the treatment of autoimmune diseases.

Common Variable Immune Deficiency and Associated Complications

Common variable immunodeficiency disorders refer to a relatively common primary immune deficiency group of diseases that present with infectious and inflammatory complications secondary to defects in antibody production and sometimes in cellular immunity. The disorder often presents in middle age or later with recurrent sinopulmonary infections, bronchiectasis, or a plethora of noninfectious complications such as autoimmune disorders, granulomatous interstitial lung disease, GI diseases, malignancies (including lymphoma), and multisystem granulomatous disease resembling sarcoidosis. Infusion of immunoglobulin by IV or subcutaneous is the mainstay of therapy. Management of complications is often difficult as immune suppression may be necessary in these conditions and entails the use of medications and biologicals which may further increase the risk for infections. Specifically, bronchiectasis, granulomatous lymphocytic interstitial lung disease, repeated sinopulmonary infections, and malignancies are sequelae of antibody deficiency that may present to the pulmonologist. This review will provide an updated understanding of the molecular aspects, differential diagnosis, presentations, and the management of common variable immunodeficiency disorders.

[Treatment of ITP and AIHA in CVID: A systematic literature review]

INTRODUCTION

Ten to 15% of common variable immunodeficiencies (CVID) develop auto-immune hemolytic anemia (AIHA) and immune thrombocytopenia (ITP). Treatment is based on immunosuppressants, which produce blocking effects in the CVID. Our objective was to assess their risk-benefit ratio in these immunocompromised patients.

METHODS

We identified 17 articles detailing the treatment of AIHA and/or ITP in patients suffering from CVID through a systematic review of the MEDLINE database.

RESULTS

The increased infectious risk with corticosteroids does not call into question their place in the first line of treatment of ITP and AIHA in CVID. High-doses immunoglobulin therapy remain reserved for ITP with a high risk of bleeding. In second-line treatment, rituximab appears to be effective, with a lower infectious risk than the splenectomy. Immunosuppressants (azathioprine, methotrexate, mycophenolate, cyclophosphamide, vincristine, ciclosporine) are moderately effective and often lead to severe infections, meaning that their use is justified only in resistant cases and steroid-sparing. Dapsone, danazol and anti-D immunoglobulins have an unfavorable risk-benefit ratio. The place of TPO receptor agonists is still to be defined. The establishment of immunoglobulin replacement in the place of immunosuppressants (except for short-term corticotherapy) or splenectomy appears to be essential to limit the risk of infections, including in the absence of previous infections.

CONCLUSION

The presence of CVID does not mean that it is necessary to give up on corticosteroids as a first-line treatment and rituximab as a second-line treatment for AIHA and ITP, but it should be in addition to immunoglobulin replacement. A splenectomy should be reserved as a third-line treatment.

Immunoglobulin replacement for secondary immunodeficiency after B-cell targeted therapies in autoimmune rheumatic disease: Systematic literature review

BACKGROUND

Consensus guidelines are not available for the use of immunoglobulin replacement therapy (IGRT) in patients developing iatrogenic secondary antibody deficiency following B-cell targeted therapy (BCTT) in autoimmune rheumatic disease.

OBJECTIVES

To evaluate the role of IGRT to manage hypogammaglobulinemia following BCTT in autoimmune rheumatic disease (AIRD).

METHODS

Using an agreed search string we performed a systematic literature search on Medline with Pubmed as vendor. We limited the search to English language papers with abstracts published over the last 10 years. Abstracts were screened for original data regarding hypogammaglobulinemia following BCTT and the use of IGRT for hypogammaglobulinemia following BCTT. We also searched current recommendations from national/international organisations including British Society for Rheumatology, UK Department of Health, American College of Rheumatology, and American Academy of Asthma, Allergy and Immunology.

RESULTS

222 abstracts were identified. Eight papers had original relevant data that met our search criteria. These studies were largely retrospective cohort studies with small patient numbers receiving IGRT. The literature highlights the induction of a sustained antibody deficiency, risk factors for hypogammaglobulinemia after BCTT including low baseline serum IgG levels, how to monitor patients for the development of hypogammaglobulinemia and the limited evidence available on intervention thresholds for commencing IGRT.

CONCLUSION

The benefit of BCTT needs to be balanced against the risk of inducing a sustained secondary antibody deficiency. Consensus guidelines would be useful to enable appropriate assessment prior to and following BCTT in preventing and diagnosing hypogammaglobulinemia. Definitions for symptomatic hypogammaglobulinemia, intervention thresholds and treatment targets for IGRT, and its cost-effectiveness are required.

Transitioning patients with immune thrombocytopenia to second-line therapy: Challenges and best practices

In patients with immune thrombocytopenia who do not adequately respond to first-line therapy, there is no clear consensus on which second-line therapy to initiate and when. This situation leads to suboptimal approaches, including prolonged exposure to treatments that are not intended for long-term use (eg, corticosteroids) and overuse of off-label therapies (eg, rituximab) while approved, more efficacious options exist. These approaches may not only fail to address symptoms and burden of disease, but may also worsen health-related quality of life. A better understanding of available second-line treatments may ensure best use of therapeutic options and thereby optimize patient outcomes.

Consequences of B-cell-depleting therapy: hypogammaglobulinemia and impaired B-cell reconstitution

Rituximab is a chimeric monoclonal antibody used to treat hematologic and autoimmune diseases by depleting CD20-expressing B cells. Patients may develop hypogammaglobulinemia following treatment, with some demonstrating failure of B-cell recovery. The true frequency of hypogammaglobulinemia and/or impaired B-cell reconstitution post rituximab is unknown due to the lack of prospective studies in different patient cohorts. The clinical significance remains controversial; some patients have recurrent infections while others are relatively asymptomatic. The aim of this review is to describe the prevalence of hypogammaglobulinemia and the associated risk for developing severe infection, in patients with differing underlying clinical conditions treated with rituximab. This may facilitate classification and prognostication of patients who develop these conditions and identify patients who may be at high risk of developing these complications, including those who may benefit from immunoglobulin replacement therapy.

Secondary antibody deficiency and immunoglobulin replacement

Antibody deficiencies can be either primary or secondary, leading to significant morbidity and mortality without appropriate management. Secondary antibody deficiency can be due to various diseases or iatrogenic causes, especially with the use of immunosuppressive agents such as B-cell depleting therapies. Unlike its primary counterpart, little is known regarding the management of secondary antibody deficiency and it remains an underappreciated entity. This is a growing concern with the growing numbers of patients on various immunosuppressant therapies and increasing survivors of autoimmune diseases and haematological malignancies. In this report, we review the diagnosis and management of secondary antibody deficiency, especially after rituximab-induced hypogammaglobulinemia.

False Negative Toxoplasma Serology in an Immunocompromised Patient with PCR Positive Ocular Toxoplasmosis

PURPOSE

The authors report a case of a 60-year-old Caucasian male with a background of treated Chronic Lymphocytic Leukaemia (CLL) with secondary hypogammaglobulinaemia present with toxoplasma chorioretinitis and negative serum toxoplasma serology on presentation and on subsequent reactivation.

METHODS

Retrospective case notes review with fundal photographs.

RESULTS

In this case, on initial presentation and on recurrence, the patient's serum anti-Toxoplasma IgG remained negative. The diagnosis was made on quantitative PCR of vitreous initially and aqueous humor on reactivation.

CONCLUSIONS

Despite negative serology, one must still consider ocular toxoplasmosis especially in CLL patients where the clinical picture could be compatible. Hypogammaglobulinaemia, the inability to produce IgG antibodies, is a well-recognized complication of CLL. Intraocular fluid sampling is essential in these cases where the sensitivity of PCR on either aqueous or vitreous humor has been shown to be higher in immunocompromised patients.

Benefits of rituximab as a second-line treatment for autoimmune haemolytic anaemia in children: a prospective French cohort study

Childhood autoimmune haemolytic anaemia (AIHA) requires second-line immunosuppressive therapy in 30-50% of cases. It appears that rituximab is indicated in such circumstances. This prospective national study reports the practice, efficacy and tolerance of rituximab in children with isolated AIHA and AIHA in the setting of Evans syndrome (ES). Sixty-one children were given rituximab between 2000 and 2014. The median interval from diagnosis to rituximab was 9·9 [interquartile range (IQR) 1·6-28·5] months. Forty-six patients responded (75%) and the 6-year relapse-free survival (RFS) was 48%. Twenty patients relapsed at a median interval of 10·8 (IQR 3·9-18·7) months, rituximab allowed steroid withdrawal in 44/61 (72%) of children. In isolated AIHA, complete response and 6-year RFS were significantly higher than in ES (P < 0·05). Ten out of 61 patients were infants, seven of who responded with a 6-year RFS of 71%. Among patients without immunoglobulin substitution before rituximab, 4 are still receiving substitutions. Five patients died, including one potentially attributable to rituximab. This large observational series of childhood AIHA established the rituximab benefit-risk ratio, allowing steroid withdrawal, with 37% of long-term responders, mainly in isolated AIHA. All subgroups of patients drew benefit. Our long-term results indicate the baseline to be challenged by new treatment approaches.

Subcutaneous immunoglobulins for the treatment of a patient with antisynthetase syndrome and secondary chronic immunodeficiency after anti-CD20 treatment: a case report

Background

Antisynthetase syndrome is a rare and debilitating multiorgan disease characterized by inflammatory myopathy, interstitial lung disease, cutaneous involvement, and frequent chronic inflammation of the joints. Standard treatments include corticosteroids and immunosuppressants. In some cases, treatment resistance may develop. Administration of immunoglobulins intravenously is recommended in patients with drug-resistant antisynthetase syndrome.

Case presentation

Here, we describe the case of a 56-year-old woman of Algerian origin. She is the first case of a patient with multidrug-resistant antisynthetase syndrome featuring pulmonary involvement and arthropathy, and chronic secondary immune deficiency with recurrent infections, after anti-CD20 treatment, in which her primary antisynthetase syndrome-related symptoms and secondary immune deficiency were treated successfully with subcutaneous administration of immunoglobulin. The administration of immunoglobulin subcutaneously was introduced at a dose of 2 g/kg per month and was well tolerated. Clinical improvement was observed within 3 months of initiation of subcutaneous administration of immunoglobulin. After 22 months of treatment, she showed a significant improvement in terms of muscle strength, pulmonary involvement, arthralgia, and immunodeficiency. Her serum creatine phosphokinase and C-reactive protein levels remained normal. Finally, she was compliant and entirely satisfied with the treatment.

Conclusions

Taken together, these observations suggest that administration of immunoglobulin subcutaneously may be a useful therapeutic approach to tackle steroid-refractory antisynthetase syndrome while ensuring minimal side effects and improved treatment compliance. This treatment also allowed, in our case, for the regression of the chronic immunodeficiency secondary to rituximab treatment.

When to initiate immunoglobulin replacement therapy (IGRT) in antibody deficiency: a practical approach

Primary antibody deficiencies (PAD) constitute the majority of all primary immunodeficiency diseases (PID) and immunoglobulin replacement forms the mainstay of therapy for many patients in this category. Secondary antibody deficiencies (SAD) represent a larger and expanding number of patients resulting from the use of a wide range of immunosuppressive therapies, in particular those targeting B cells, and may also result from renal or gastrointestinal immunoglobulin losses. While there are clear similarities between primary and secondary antibody deficiencies, there are also significant differences. This review describes a practical approach to the clinical, laboratory and radiological assessment of patients with antibody deficiency, focusing on the factors that determine whether or not immunoglobulin replacement should be used. The decision to treat is more straightforward when defined diagnostic criteria for some of the major PADs, such as common variable immunodeficiency disorders (CVID) or X-linked agammaglobulinaemia (XLA), are fulfilled or, indeed, when there is a very low level of immunoglobulin production in association with an increased frequency of severe or recurrent infections in SAD. However, the presentation of many patients is less clear-cut and represents a considerable challenge in terms of the decision whether or not to treat and the best way in which to assess the outcome of therapy. This decision is important, not least to improve individual quality of life and reduce the morbidity and mortality associated with recurrent infections but also to avoid inappropriate exposure to blood products and to ensure that immunoglobulin, a costly and limited resource, is used to maximal benefit.

Vaccinations and secondary immune thrombocytopenia with antiphospholipid antibodies by human papillomavirus vaccine

A 13-year-old girl developed immune thrombocytopenic purpura (ITP) and concomitant positive antiphospholipid antibodies (aPL) following vaccination with a quadrivalent human papillomavirus (HPV) vaccine. During the course of a disease, she developed clinical manifestation with bleeding and she was treated with intravenous immunoglobulins. Consequently, the number of her platelets remained critically low and she was put on corticosteroids and rituximab. Since then, her platelet count remain within the normal range, but her aPL are still present.

Rituximab salvage therapy in adults with immune thrombocytopenia: retrospective study on efficacy and safety profiles

Splenectomy remains the preferred treatment for chronic immune thrombocytopenia (ITP) after corticosteroid failure, despite the risks of despite surgical complications and infection. The aim of this study was to assess the efficacy of and tolerance to rituximab through a retrospective analysis of 35 refractory/relapsing ITP patients treated from 2004 to 2013. The median age of subjects was 46 years (14-80). Rituximab was given at a weekly dose of 375 mg/m(2) for 4 weeks. Median time from diagnosis to first infusion was 17 months (1-362) and follow-up was 47 months (2-133). The overall response rates at 1 and 2 years after the first infusion were 47 and 38 %, with complete response rates of 24 and 25 %, respectively. Median duration of response was 38 months (1-123), with 37 % of patients maintaining a durable response (>1 year). Twenty-nine percent of patients had undergone splenectomy. A durable response after rituximab was more frequently observed in patients undergoing second-line therapy than those in third or later (83 versus 35 %, P = 0.01). Forty-four percent of patients experienced mild hypogammaglobulinaemia after rituximab, and no clinical infection occurred. To conclude, rituximab should be considered as an alternative treatment to splenectomy. Its efficacy and safety profile should lead us to choose this medical option therapy before surgery for ITP patients.

Rituximab is an effective and safe treatment of relapse in elderly patients with resistant warm AIHA

We evaluated the efficacy and safety of rituximab for the treatment of 23 elderly patients (median age 78 years) with warm autoimmune haemolytic anaemia (AIHA). The median follow-up was 31 months. Patients had received one to five previous treatments. Rituximab was administered by intravenous infusion at a dose of 375 mg/m(2) once weekly for 4 weeks. The OR rate was 86.9 % (CR = 39.1 %, PR = 47.8 %). Median OS was 87 months. The median OS of patients who reached CR could not be calculated, and that of patients with PR was 67 months. At last follow-up, eight of the 20 responding patients, including one patient in CR and seven in PR, had relapsed after a median of 6 months. Failure to achieve CR was a risk factor for relapse (p = 0.028). We did not identify any pretreatment characteristics predictive of response to rituximab. In conclusion, rituximab is an effective treatment for elderly patients with refractory warm AIHA.

Rituximab in autoimmune thrombotic thrombocytopenic purpura: A success story

Despite a significant improvement of thrombotic thrombocytopenic purpura (TTP) prognosis since the use of plasma exchange, morbidity and mortality remained significant because of poor response to standard treatment or exacerbations and relapses. Rituximab, a chimeric monoclonal antibody directed against the B-lymphocyte CD20 antigen, has shown a particular interest in this indication. Recent studies also reported strong evidence for its efficiency in the prevention of relapses. This review addresses these recent progresses and still opened questions in this topic: should rituximab be proposed in all patients at the acute phase? Should all patients benefit from a preemptive treatment? Is the infectious risk acceptable in this context?

Need for an improved vaccination rate in primary immune thrombocytopenia patients exposed to rituximab or splenectomy. A nationwide population-based study in France

International guidelines on immune thrombocytopenia (ITP) management recommend vaccination against Streptococcus pneumoniae (S.p.), Haemophilus influenza b (Hib) and Neisseiria meningitidis (N.m.) before splenectomy. French guidelines also recommend these vaccinations before rituximab. The aim of this study was to assess the application of these recommendations. The French Adult ITP: a French pHarmacoepidemiological study (FAITH, n°ENCEPP 4574) is aimed at following in the French national health insurance system database (SNIIRAM) the cohort of all incident and persistent or chronic primary ITP adults treated in France. We assessed vaccine exposure in the 1,106 patients who entered the FAITH cohort between 2009 and 2011. Vaccination was said "recommended" if performed at least 2 weeks before rituximab or splenectomy accordingly with French guidelines. Among the 423 non-splenectomized patients exposed to rituximab, vaccination rates against S.p., Hib and N.m. were respectively 32.4%, 18.9%, and 3.8%. It was recommended in 12.8%, 6.6%, and 1.2% of the patients, respectively. Among the 178 splenectomized patients, vaccination rates were 70.2%, 47.0%, and 11.9%, respectively (recommended: 60.1%, 35.7%, and 9.5%). Among the splenectomized patients previously exposed to rituximab (n = 67), 53.3% of the vaccinations occurred during the semester following a rituximab infusion that is during the maximal B-cell depletion period. In multivariate analyses, a disease duration exceeding 3 months was the sole factor associated to recommended vaccination in rituximab-treated patients as well as in splenectomized patients. This study stresses the need of better and earlier vaccination of ITP patients.