Persistent Hypogammaglobulinemia after Receiving Rituximab Post-HSCT Is Not Caused by an Intrinsic B Cell Defect.

In the setting of hematopoietic stem cell transplantation (HSCT), Rituximab (RTX) is used for the treatment and prevention of EBV-associated post-transplantation lymphoproliferative disease or autoimmune phenomena such as autoimmune hemolytic anemia (AIHA). Persistent hypogammaglobulinemia and immunoglobulin substitution dependence has been observed in several patients after RTX treatment despite the normalization of total B cell numbers. We aimed to study whether this is a B cell intrinsic phenomenon. We analyzed four patients with different primary diseases who were treated with myeloablative conditioning and matched unrelated donor HSCT who developed persistent hypogammaglobulinemia after receiving RTX treatment. They all received RTX early after HSCT to treat EBV infection or AIHA post-HSCT. All patients showed normalized total B cell numbers but absent to very low IgG positive memory B cells, and three lacked IgA positive memory B cells. All of the patients had full donor chimerism, and none had encountered graft-versus-host disease. Sorted peripheral blood naïve B cells from these patients, when stimulated with CD40L, IL21, IL10 and anti-IgM, demonstrated intact B cell differentiation including the formation of class-switched memory B cells and IgA and IgG production. Peripheral blood T cell numbers including CD4 follicular T-helper (Tfh) cells were all within the normal reference range. In conclusion, in these four HSCT patients, the persistent hypogammaglobulinemia observed after RTX cannot be attributed to an acquired intrinsic B cell problem nor to a reduction in Tfh cell numbers.

An International Survey of Allogeneic Hematopoietic Cell Transplantation for X-Linked Agammaglobulinemia.

PURPOSE: X-linked agammaglobulinemia (XLA) is an inborn error of immunity caused by variants in Bruton's tyrosine kinase (BTK). XLA patients require lifelong immunoglobulin replacement therapy (IgRT). Only few XLA patients are indicated for allogeneic hematopoietic cell transplantation (HCT) because of severe complications. Accordingly, the published transplantation experience in XLA is minimal. We aimed to collect clinical data of XLA patients who received HCT in an international framework and to establish appropriate transplantation criteria and methods for XLA patients. METHODS: XLA patients were recruited through a questionnaire and a literature review. The data are on patient characteristics and transplantation methods and outcomes. RESULTS: In this study, twenty-two XLA patients who underwent HCT were recruited. The indication for HCT was recurrent or life-threatening infection in sixteen patients, malignancy in three, and other factors in three. A myeloablative conditioning, reduced toxicity myeloablative conditioning (RT-MAC), and reduced intensity conditioning (RIC) were selected in four, ten, and eight patients, respectively. Engraftment was achieved in 21 patients (95%). In all patients, 2-year overall survival (OS) and event-free survival (EFS) were 86% and 77%, respectively. In patients who received RT-MAC or RIC using treosulfan, busulfan, or melphalan, 2-year OS and EFS were 82% and 71%, respectively. Finally, twenty-one patients (95%) obtained complete or stable high-level mixed chimerism (50-95%), and the 1-year discontinuation rate of IgRT was 89%. CONCLUSION: Based on the concept in which IgRT is the standard treatment for XLA, HCT may be an effective and safe alternative treatment option for XLA patients, and IgRT can be discontinued following transplantation. It is ideal to perform HCT in XLA patients for whom transplantation is indicated before they develop organ damage.

[Prevalence of persistent hypogammaglobulinemia in patients with autoimmune rheumatic disease who received treatment with Rituximab in a national medical center in Mexico]. / Prevalencia de hipogammaglobulinemia persistente en pacientes con enfermedad autoinmune que reciben rituximab en un centro de referencia nacional en México.

OBJECTIVE: To describe the prevalence of persistent hypogammaglobulinemia in patients receiving Rituximab as a treatment for autoimmune rheumatological diseases. METHODS: A transversal, retrospective and unicentric study, carried out in patients with autoimmune rheumatic diseases who were admitted to the Rheumatology service of the Hospital de Especialidades Dr. Antonio Fraga Mouret, Centro Médico Nacional La Raza, Mexico City, to receive treatment with rituximab between January 2013 and January 2018. Descriptive and inferential statistics of serum levels of immunoglobulins, clinical-demographic characteristics, diagnosis, and treatment received were performed. RESULTS: from 262 patients with autoimmune rheumatological disease who received treatment with Rituximab; We identified 8 patients with persistent hypogammaglobulinemia (6 women and 2 men), this is a prevalence of 3.1%. No associated factors with the development of hypogammaglobulinemia were identified. CONCLUSIONS: Until now, no associated prognostic or predictive factors have been identified with persistent hypogammaglobulinemia. Additional prospective studies are required to understand more precisely the implications of persistent hypogammaglobulinemia in patients with autoimmune diseases.

OBJECTIVO: Determinar la prevalencia de hipogammaglobulinemia persistente en pacientes con enfermedades reumatológicas autoinmunes que reciben rituximab. MÉTODOS: Estudio trasversal, retrospectivo y unicéntrico, emprendido en pacientes con enfermedades reumatológicas autoinmunes, que acudieron a la Consulta externa del servicio de Reumatología del Hospital de Especialidades Dr. Antonio Fraga Mouret, Centro Médico Nacional La Raza, Ciudad de México, entre enero de 2013 y enero de 2018, para recibir tratamiento con rituximab. El análisis de los datos se efectuó con estadística descriptiva e inferencial, para la evaluación de las concentraciones séricas de inmunoglobulinas, características clínico demográficas, diagnóstico y tratamiento. RESULTADOS: Estudio trasversal, retrospectivo y unicéntrico, emprendido en pacientes con enfermedades reumatológicas autoinmunes, que acudieron a la Consulta externa del servicio de Reumatología del Hospital de Especialidades Dr. Antonio Fraga Mouret, Centro Médico Nacional La Raza, Ciudad de México, entre enero de 2013 y enero de 2018, para recibir tratamiento con rituximab. El análisis de los datos se efectuó con estadística descriptiva e inferencial, para la evaluación de las concentraciones séricas de inmunoglobulinas, características clínico demográficas, diagnóstico y tratamiento. CONCLUSIONES: Hasta el momento no se han identificado factores asociados, pronósticos o predictivos, con hipogammaglobulinemia persistente. Se requieren estudios prospectivos adicionales para conocer con mayor precisión las implicaciones de la hipogammaglobulinemia persistente en pacientes con enfermedades autoinmunes.

Effect of rituximab on immune status in children with mature B-cell non-Hodgkin lymphoma: a prespecified secondary analysis of the Inter-B-NHL Ritux 2010 trial.

BACKGROUND: Survival of children and adolescents with high-risk, mature B-cell non-Hodgkin lymphoma is improved by the addition of rituximab to chemotherapy. The effect of rituximab on immune reconstitution after therapy has not been well described. Herein, we evaluate the immune effects of the addition of rituximab to intensive chemotherapy, a prespecified secondary aim of the Inter-B-NHL Ritux 2010 trial. METHODS: The Inter-B-NHL Ritux 2010 trial was an international, open-label, randomised, phase 3 trial in children (age 6 months to 18 years) with high-risk, mature B-cell non-Hodgkin lymphoma, comparing chemotherapy alone or chemotherapy with rituximab. Measures of immune status were completed at baseline, 1 month from the end of treatment, and 1 year from the start of therapy, and yearly thereafter until normalised. For this secondary analysis, we report on the proportions of patients with low lymphocyte counts and immunoglobulin concentrations at these timepoints with total lymphocyte count, B-cell count, and IgG concentration as the main endpoints. Other endpoints of interest included exposure to immunoglobulin replacement therapy and vaccine serologies. The population assessed for immune endpoints was the eligible per-protocol population with at least one immune parameter at one timepoint. Comparisons of immune status were made between the randomised treatment groups. Safety in the post-therapy period was assessed in the population eligible for the immunity study who were followed up at least 3 months after the end of treatment and without cancer-related events. The Inter-B-NHL Ritux 2010 study was registered with ClinicalTrials.gov, NCT01516580; status completed, with analyses of secondary aims ongoing. FINDINGS: From Dec 19, 2011, to June 13, 2017, 421 patients (344 [82%] boys and 77 [18%] girls; mean age was 8·8 years [SD 4·1]) were enrolled and had immune data at baseline during follow-up, or both. The study population included randomly assigned patients (n=289) and a non-randomised cohort enrolled after the planned interim analysis (n=132). At baseline, 99 (34%) of 290 patients with available data (excluding patients with bone marrow disease with peripheral blast cells) had lymphopenia, and 178 (48%) of 368 had hypogammaglobulinemia. 1 month from the end of therapy, patients who received chemotherapy with rituximab were more likely than those who received chemotherapy alone to have lymphopenia (86 [81%] of 106 vs 53 (60%) of 89, odds ratio [OR] 2·92 [95% CI 1·53-5·57], p=0·0011), B-cell lymphopenia (72 [96%] of 75 vs 36 [64%] of 56, OR 13·33 [3·71-47·84], p<0·0001), and hypogammaglobulinemia (67 [71%] of 95 vs 37 [47%] of 79, OR 2·72 [1·45-5·07], p=0·0017). Differences remained at 1 year for hypogammaglobulinemia only (52 [55%] of 94 vs 16 [25%] of 63, OR 3·64 [1·81-7·31], p=0·0003). Patients in the chemotherapy with rituximab group were more likely than those in the chemotherapy group to receive immunoglobulin replacement (26 [16%] 164 vs nine [7%] of 158, hazard ratio [HR] 2·63 [95% CI 1·23-5·62], p=0·010), mainly due to low immunoglobulin concentration. In the combined treatment groups, including non-randomly assigned patients, the proportion of patients who had loss of protective serologies to a vaccine preventable infection varied from four (9%) of 47 for polio to 21 (42%) of 50 for Streptococcus pneumoniae (pneumococcus). One patient (chemotherapy with rituximab group) had a life-threatening infectious event of polymicrobial bacterial sepsis reported 2 months after the final chemotherapy administration. INTERPRETATION: Children with high-risk mature B-cell non-Hodgkin lymphoma receiving chemotherapy with rituximab were at risk of prolonged hypogammaglobulinemia, although severe infections were rare. Strategies for immunoglobulin replacement and revaccination are needed. FUNDING: Clinical Research Hospital Program of the French Ministry of Health, Cancer Research UK, National Institute for Health Research Clinical Research Network in England, Children's Cancer Foundation Hong Kong, US National Cancer Institute, F Hoffmann-La Roche.

Hypogammaglobulinemia in pediatric kidney transplant recipients.

Infections remain the most common cause of hospitalization after kidney transplantation, contributing to significant post-transplant morbidity and mortality. There is a growing body of literature that suggests that immunoglobulins may have a significant protective role against post-transplant infections, although the literature remains sparse, inconsistent, and not well publicized among pediatric nephrologists. Of great concern are data indicating a high prevalence of immunoglobulin abnormalities following transplantation and a possible link between these abnormalities and poorer outcomes. Our educational review focuses on the epidemiology and risk factors for the development of immunoglobulin abnormalities after kidney transplantation, the outcomes in patients with low immunoglobulin levels, and studies evaluating possible interventions to correct these immunoglobulin abnormalities.

Síndrome de Good, una causa infrecuente de diarrea crónica / Good Syndrome, a rare cause of chronic diarrhea

Chronic diarrhea is a frequent cause of consultation in daily clinical practice. There are multiple diagnostic algorithms that allow a staggered approach to the most frequent pathologies, leaving out some lesser-known ones. This article reports the case of a 66-year-old female patient with a history of arterial hypertension, dyslipidemia and resected AB thymoma and a history of chronic diarrhea of 8 weeks of evolution. The etiological study ruled out infectious causes, celiac disease and negative viral serology. Due to a history of thymoma, immunoglobulin count was performed, showing severe pan-hypogammaglobulinemia. Good's Syndrome is the combination of thymoma and hypogammaglobulinemia, where patients may present with diarrhea secondary to immunodeficiency. Hypogammaglobulinemia associated with the presence of a thymoma is a rare cause but widely described in the literature as Good's Syndrome. Therefore, it seems relevant to describe a case, its approach and subsequent management.

La diarrea crónica constituye una causa frecuente de consulta en la práctica clínica diaria. Existen múltiples algoritmos diagnósticos que permiten realizar un abordaje escalonado de las patologías más frecuentes y permiten descartar algunas menos conocidas. En el presente artículo se reporta el caso de una paciente de género femenino de 66 años, antecedentes de hipertensión arterial, dislipidemia y timoma AB resecado con historia de diarrea crónica de 8 semanas de evolución. Dentro del estudio etiológico se descartan las causas infecciosas, enfermedad celíaca y serologías virales negativas. Por antecedente de timoma, se realizó recuento de inmunoglobulinas, evidenciando una severa pan-hipogammaglobulinemia. El Síndrome de Good es la combinación de timoma e hipogammaglobulinemia, donde los pacientes podrían presentar diarreas secundarias a inmunodeficiencia. La hipogammaglobulinemia asociada a la presencia de un timoma es una causa poco frecuente pero ampliamente descrita en la literatura como Síndrome de Good. Por lo antes señalado, nos parece relevante describir un caso, su abordaje y manejo posterior.

Long-term Effectiveness and Safety of Rituximab in Neuromyelitis Optica Spectrum Disorder and MOG Antibody Disease.

BACKGROUND AND OBJECTIVES: Rituximab is used widely for relapse prevention in neuromyelitis optica spectrum disorder (NMOSD) and myelin oligodendrocyte glycoprotein (MOG)-IgG-associated disease (MOGAD); however, data regarding the effectiveness and safety of long-term rituximab use in these conditions are limited. In this study, we sought to evaluate long-term clinical outcomes in patients with aquaporin-4 IgG-seropositive (AQP4-IgG+) NMOSD and MOGAD treated with rituximab. METHODS: We performed a retrospective chart review of patients with AQP4-IgG+ NMOSD or MOGAD followed at the Johns Hopkins Neuromyelitis Optica Clinic and included patients who had received at least 1 dose of rituximab. RESULTS: We identified 111 patients with NMOSD and 23 patients with MOGAD who fulfilled the inclusion criteria. The median duration of rituximab treatment for the patients with NMOSD was 3.7 years (range: 0.5-13.2 years) and for the patients with MOGAD was 2.1 years (range: 0.5-7.0 years). The annualized relapse rate (ARR) decreased after rituximab initiation in both NMOSD (median ARR: pretreatment 1.1, posttreatment 0; p < 0.001) and MOGAD (median ARR: pretreatment 1.9, posttreatment 0.3; p = 0.002). Relapses on rituximab occurred in 31 patients with NMOSD (28%) and 14 patients with MOGAD (61%). The majority of NMOSD treatment failures (37/48 relapses; 77%) occurred either within the initial 6 months after starting rituximab (n = 13 relapses) or in the setting of delayed/missed rituximab doses and/or peripheral B-cell reconstitution (n = 24 relapses), whereas in MOGAD, these circumstances were present in a smaller proportion of treatment failures (19/35 relapses; 54%). The risk of relapse on rituximab was greater for patients with MOGAD compared with patients with NMOSD (hazard ratio: 2.8, 95% CI: 1.5-5.2, p = 0.001). Infections requiring hospitalization occurred in 13% and immunoglobulin G (IgG) hypogammaglobulinemia in 17% of patients. The median rituximab treatment duration before IgG hypogammaglobulinemia onset was 5.4 years (interquartile range: 3.8-7.7 years). DISCUSSION: Rituximab treatment is associated with the reduced annualized relapse rate in AQP4-IgG-seropositive NMOSD, especially in the absence of gaps in treatment and/or B-cell reconstitution. In MOGAD, although a reduction in relapses was observed after initiation of rituximab, this association appeared to be less robust than in AQP4-IgG-seropositive NMOSD. Severe infections and hypogammaglobulinemia occurred in a significant proportion of patients, highlighting the need for close monitoring of infectious complications. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that rituximab decreases the annualized relapse rate in AQP4-IgG-seropositive NMOSD and MOGAD.

Hypogammaglobulinemia is associated with reduced antibody response after anti-SARS-CoV-2 vaccination in MS patients treated with antiCD20 therapies.

BACKGROUND: COVID-19 vaccination is highly recommended to multiple sclerosis (MS) patients. Little is known about the role of patients' clinical and demographic characteristics in determining antibody response. METHODS: We evaluated safety and efficacy of anti-SARS-CoV-2 vaccines on 143 included MS patients. Then, we analyzed antibody titer in a subgroup, assessing clinical and demographic variables associated with protection and antibody titer. RESULTS: After completing the vaccination cycle, the rate of local adverse events was similar after the first and second dose. A higher proportion of systemic AEs was reported after the second dose (65.7% vs 24.5% after the first dose). Antibody response was evaluated in 97 patients. Higher EDSS (OR 0.6, 95% CI 0.4-0.9, p = 0.006) and treatment with antiCD20 (OR 0.02, 95% CI 0.003-0.098, p 0.001) were associated with a lower chance of having an efficacious response. Higher weight was associated with higher Ab titer (ß = 15.2, 95% CI 2.8-27.6, p = 0.017), while treatment with antiCD20 with lower titers (ß = - 1092.3, 95% CI - 1477.4 to - 702.2, p < 0.001). In patients treated with antiCD20, hypogammaglobulinemia (ß - 543, 95% CI - 1047.6 to - 39.1, p = 0.036) and treatment duration (ß - 182, 95% CI - 341.4 to - 24.3, p = 0.027) were associated with lower Ab titer. CONCLUSION: Our study confirms that COVID-19 vaccination in MS patient is safe and effective in preventing symptomatic COVID-19 and should be recommended to all patients. Moreover, we suggest a possible role of hypogammaglobulinemia in reducing Ab response in patients treated with antiCD20 therapies.

Chronic hypogammaglobulinemia after allogeneic stem cell transplantation and their treatment with subcutaneous immunoglobulin in pediatric patients.

INTRODUCTION: Hypogammaglobulinemia in the first months after allogeneic hematopoietic stem cell transplantation (HSCT) is common in paediatric patients. During this phase, replacement therapy with human immunoglobulin must be administered parenterally to prevent infections. In some cases, this hypogammaglobulinemia persists over time, which forces further treatment when the patient is usually no longer a carrier of a central line, making them ideal candidates for subcutaneous replacement therapy. There is little published literature describing the use of this method in paediatric patients undergoing HSCT, widely described in replacement treatment in children with primary immunodeficiencies with very good results. PATIENTS AND METHODS: An observational, descriptive, longitudinal and retrospective study is carried out. During the years 2008-2019, we evaluated all paediatric patients undergoing HSCT in our center with persistent chronic hypogammaglobulinemia (for over a year). The treatment phase with intravenous immunoglobulin (Privigen®) and the first four years of treatment with subcutaneous immunoglobulin (Hizentra®) are evaluated using a questionnaire. RESULTS: During the years 2008-2019, 175 patients underwent HSCT, 143 (82%) of whom exceeded three months after transplantation. Three (2%) of them had persistent hypogammaglobulinemia. All three share factors described in the literature involved in immune reconstitution. After analysing the questionnaire, it is observed that switching from intravenous to subcutaneous gammaglobulin has involved a great improvement in their quality of life. CONCLUSIONS: The origin of chronic hypogammaglobulinemia in our patients shows different factors and cannot be attributed to a single cause. Due to the limited number of patients no conclusions can be drawn at the population level. We have been able to observe that replacement treatment with Hizentra 20% has been as effective as the intravenous administration without evidence of an increase in bacterial infections. Furthermore, it has also led to an improvement in quality of life and increased comfort, as the patients themselves have stated.

Managing hypogammaglobulinemia in patients treated with CAR-T-cell therapy: key points for clinicians.

INTRODUCTION: The unprecedented success of chimeric antigen receptor (CAR)-T-cell therapy in the management of B-cell malignancies comes with a price of specific side effects. Healthy B-cell depletion is an anticipated 'on-target' 'off-tumor' side effect and can contribute to severe and prolonged hypogammaglobulinemia. Evidence-based guidelines for the use of immunoglobulin replacement therapy (IGRT) for infection prevention are lacking in this population. AREAS COVERED: This article reviews the mechanisms and epidemiology of hypogammaglobulinemia and antibody deficiency, association with infections, and strategies to address these issues in CD19- and BCMA-CAR-T-cell recipients. EXPERT OPINION: CD19 and BCMA CAR-T-cell therapy result in unique immune deficits due to depletion of specific B-lineage cells and may require different infection prevention strategies. Hypogammaglobulinemia before and after CAR-T-cell therapy is frequent, but data on the efficacy and cost-effectiveness of IGRT are lacking. Monthly IGRT should be prioritized for patients with severe or recurrent bacterial infections. IGRT may be more broadly necessary to prevent infections in BCMA-CAR-T-cell recipients and children with severe hypogammaglobulinemia irrespective of infection history. Vaccinations are indicated to augment humoral immunity and can be immunogenic despite cytopenias; re-vaccination(s) may be required. Controlled trials are needed to better understand the role of IGRT and vaccines in this population.

Humoral immune depression following autologous stem cell transplantation is a marker of prolonged response duration in patients with mantle cell lymphoma.

Rituximab maintenance (RM) after autologous stem cell transplantation (ASCT) is standard-of-care for young patients with mantle cell lymphoma (MCL). RM may enhance post-transplantation immune depression and risk of infections. We compared infection incidence and immune consequences of RM versus observation in transplanted MCL patients. All randomized patients included in the LyMa trial were eligible. The following parameters were collected prospectively: occurrence of fever, infection, hospitalization, neutropenia, hypogammaglobulinemia, CD4 lymphopenia and γ globulin (Ig) substitution. The post-ASCT period was divided into four periods in order to assess the possible effects of RM or ASCT on immune status. Each arm included 120 patients. Concerning infection incidence and all biological parameters, there was no difference between the two arms during the first year post ASCT. After this period, RM patients were more exposed to fever (P=0.03), infections (P=0.001), hypogammaglobulinemia (P=0.0001) and Ig substitution (P<0.0001). Incidences of hospitalization, neutropenia and CD4 lymphopenia were not different between the two arms. The number of rituximab injections was correlated with infections and hypogammaglobulinemia, P<0.0001 and P=0.001; but was not correlated with neutropenia and CD4 lymphopenia. Ig substitution did not modify infection incidence. Patients who presented hypogammaglobulinemia <6 g/L or <4 g/L had longer 3-years progression-free survival (PFS), this applies to RM patients (P=0.012 and P=0.03) and to the global cohort (P=0.008 and P=0.003). Hypogammaglobulinemia did not influence overall survival. Occurrence of infectious event, neutropenia and CD4 lymphopenia did neither influence PFS nor overall survival. Post-ASCT RM in MCL patients causes sustained hypogammaglobulinemia, which is independently correlated with improved PFS.

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.

The impact of anti-CD20-based therapy on hypogammaglobulinemia in patients with follicular lymphoma.

Although treatment with anti-CD20 monoclonal antibodies (mAb) has improved outcomes in B-cell malignancies, it's associated with increased risk of hypogammaglobulinemia (HG). Our study aimed to determine the effects of anti-CD20 mAb on serum immunoglobulins (Ig) in follicular lymphoma (FL). Ig concentrations, infectious complications, and need for intravenous Ig were evaluated by level of exposure to anti-CD20 mAb in 380 patients. Prevalence of HG significantly differed by level of treatment exposure (p < 0.001). Single course anti-CD20 mAb was associated with rising IgG (+10.3 mg/dL/year), whereas the addition of maintenance therapy (-7.4 mg/dL/year) or multiple courses of treatment (-10.3 mg/dL/year) was associated with declining IgG. Among patients treated with anti-CD20 mAb, 45.2% developed IgG-HG and 10.3% developed symptomatic IgG-HG. Pretreatment IgG levels gradually declined in all patients, suggesting tumor burden may contribute to HG. Baseline and periodic monitoring of serum Ig is appropriate in patients with FL, including those managed with active surveillance.

Immunoglobulin replacement therapy in chronic lymphocytic leukaemia patients with hypogammaglobulinaemia and infection.

OBJECTIVES: To analyse total national utilisation of immunoglobulin (Ig) replacement therapy (IgRT) for Chronic Lymphocytic Leukaemia patients with acquired hypogammaglobulinaemia and severe and/or recurrent bacterial infections. METHODS: In 2007, the National Blood Authority first published Criteria for the clinical use of intravenous immunoglobulin in Australia. The Australian Red Cross Lifeblood assessed, approved, and recorded all supply with patient demographics, distribution data, intravenous Ig (IVIg) volumes and treatment episodes. IVIg was the sole product used in Australia from 2008-2013 inclusive. RESULTS: From 2008 to 2013 across Australia, 2734 individual CLL patients received 48,870 treatment episodes using a total 1,324,926 g of IVIg therapy. Six IVIg products were available, with domestically manufactured Intragam® P accounting for 89.7% of supply. The average age for first dose was 74 years. Males received 60.6% of the total treatment episodes representing 20% more than females. The average pre-treatment IgG level was 4.03 ± 2.03 g/L (range 0.30-10.50 g/L). A sustained average annual increased IVIg utilisation of 5.5% was observed. There was significant regional variation consistent with differences in prescriber preferences across states and territories. CONCLUSION: This study provides a globally unique insight into IgRT supply and demand in CLL patients by analysis of total national use in Australia over a 6-year period.

Serum IgG and lymphocyte counts are useful for the early detection of infection in patients receiving bendamustine-rituximab therapy.

Bendamustine-rituximab (BR) therapy has been established as a highly effective regimen for indolent non-Hodgkin lymphoma (NHL). However, patients who receive BR therapy exhibit persistent hypogammaglobulinemia and lymphopenia, resulting in an increased incidence of infections. As a sustained immunosuppressive state is a risk factor for infections, early predictive biomarkers for infections related to BR therapy need to be identified. We retrospectively analyzed 61 patients with indolent NHL who were followed up for 2 years after the end of BR therapy. Progression-free survival was significantly influenced by the incidence of infections. Patients with infections related to BR therapy exhibited persistent hypogammaglobulinemia and lymphopenia. In addition, we determined the cutoff values of serum IgG values and lymphocyte counts for infections using receiver operating characteristic curve analysis. Minimum serum IgG and lymphocyte counts at the first BR treatment cycle were significantly associated with the incidence of infections during and after BR treatment. Furthermore, the development of skin reactions during BR therapy was significantly associated with the incidence of infections after BR therapy. Our study suggested that these values and symptom are predictive biomarkers for infections related to BR therapy. Based on these findings, better management of indolent NHL patients will be possible.

Intravenous immunoglobulin in heart transplant recipients with mild to moderate hypogammaglobulinemia and infection.

BACKGROUND: Hypogammaglobulinemia (HGG) is a complication of solid organ transplantation leading to increased risk of infections. Intravenous immunoglobulin G (IVIG) replacement in patients with HGG may be able to reduce risk and morbidity associated with infection; however, there is scarce data about IVIG in mild to moderate HGG (IgG 400-700 mg/dl) and heart transplant recipients. METHODS: A single center, retrospective study was performed in heart transplant recipients with mild (IgG 500-700 mg/dl) to moderate (IgG 400-499 mg/dl) HGG in the presence of an infection. RESULTS: Forty-two patients were included in this study; 19 patients (45.2%) received IVIG and 23 (54.8%) patients did not. Patients in the IVIG group received on average one dose of IVIG at 0.5 g/kg. No differences in incidence of new infection at 3 months (26.3% vs. 17.4%; P = .71) and 6 months (42.1% vs. 34.8%; P = .63) were observed between the IVIG and non-IVIG groups. Infections based on mild or moderate HGG also had no differences at 3 and 6 months. CONCLUSION: Our findings suggest that a single infusion of IVIG in mild to moderate HGG may have little to no benefit in reducing incidence of new infections. Larger prospective studies are needed to confirm these findings.

Hypogammaglobulinemia After Chimeric Antigen Receptor (CAR) T-Cell Therapy: Characteristics, Management, and Future Directions.

Chimeric antigen receptor (CAR) T-cell therapy is a dynamic therapy of engineered T cells targeting neoplastic cells, which offers impressive long-term remissions for aggressive relapsed/refractory hematologic malignancies. However, side effects including severe infections can be life-threatening. Multiple factors, including cytokine release syndrome, B-cell aplasia, and hypogammaglobulinemia, contribute to infection risk. B-cell aplasia is an expected on-target, off-tumor effect of CD19+-targeted CAR T cells and leads to hypogammaglobulinemia. We review hypogammaglobulinemia observed in the 5 currently Food and Drug Administration-approved CAR T-cell therapies and other CAR T-cell products evaluated in clinical trials, and discuss hypogammaglobulinemia onset, duration, and immune recovery. We review associations between hypogammaglobulinemia and infections, with a discussion informed by other known B-cell-depleting contexts. Differences in hypogammaglobulinemia between children and adults are identified. We integrate management strategies for evaluation and immunoglobulin replacement from clinical studies, expert recommendations, and organizational guidelines. Notably, our review also highlights newer CAR T-cell products targeting different B-cell antigens, including B-cell maturation antigen, signaling lymphocytic activation molecule, and κ light chains. Finally, we identify key areas for future study to mitigate and treat hypogammaglobulinemia resulting from this transformative therapy.

Therapeutic options for CTLA-4 insufficiency.

BACKGROUND: Heterozygous germline mutations in cytotoxic T lymphocyte-associated antigen-4 (CTLA4) impair the immunomodulatory function of regulatory T cells. Affected individuals are prone to life-threatening autoimmune and lymphoproliferative complications. A number of therapeutic options are currently being used with variable effectiveness. OBJECTIVE: Our aim was to characterize the responsiveness of patients with CTLA-4 insufficiency to specific therapies and provide recommendations for the diagnostic workup and therapy at an organ-specific level. METHODS: Clinical features, laboratory findings, and response to treatment were reviewed retrospectively in an international cohort of 173 carriers of CTLA4 mutation. Patients were followed between 2014 and 2020 for a total of 2624 months from diagnosis. Clinical manifestations were grouped on the basis of organ-specific involvement. Medication use and response were recorded and evaluated. RESULTS: Among the 173 CTLA4 mutation carriers, 123 (71%) had been treated for immune complications. Abatacept, rituximab, sirolimus, and corticosteroids ameliorated disease severity, especially in cases of cytopenias and lymphocytic organ infiltration of the gut, lungs, and central nervous system. Immunoglobulin replacement was effective in prevention of infection. Only 4 of 16 patients (25%) with cytopenia who underwent splenectomy had a sustained clinical response. Cure was achieved with stem cell transplantation in 13 of 18 patients (72%). As a result of the aforementioned methods, organ-specific treatment pathways were developed. CONCLUSION: Systemic immunosuppressants and abatacept may provide partial control but require ongoing administration. Allogeneic hematopoietic stem cell transplantation offers a possible cure for patients with CTLA-4 insufficiency.

CAR-T cell: Toxicities issues: Mechanisms and clinical management.

CAR-T cells are modified T cells expressing a chimeric antigen receptor targeting a specific antigen. They have revolutionized the treatment of B cell malignancies (aggressive lymphomas, B-ALL), and this has raised hopes for application in many other pathologies (myeloma, AML, solid tumors, etc.). However, these therapies are associated with novel and specific toxicities (cytokine release syndrome and neurotoxicity). These complications, although mostly managed in a conventional hospitalization unit, can sometimes be life threatening, leading to admission of patients to the intensive care unit. Management relies mainly on anti-IL6R (tocilizumab) and corticosteroids. However, the optimal treatment regimen is still a matter of debate, and the management of the most severe forms is even less well codified. In addition to CRS and ICANS, infections, cytopenia and hypogammaglobulinemia are other frequent complications. This article reviews the mechanisms, risk factors, clinical presentation, and management of these toxicities.