Risk factors for hypogammaglobulinemia and association with relapse and severe infections in ANCA-associated vasculitis: A cohort study.

OBJECTIVES: B-cell depletion induced by rituximab (RTX) in ANCA-associated vasculitis (AAV) is a risk factor for hypogammaglobulinemia. Aggregating data on gammaglobulin levels kinetics during RTX and its association with the risk of relapse and severe infection is of interest. METHODS: Gammaglobulin levels were collected before induction therapy and during RTX maintenance therapy. We used different definitions of gammaglobulin decline: 1/gammaglobulin levels <6 g/L after induction; 2/>25 % decline in gammaglobulin levels between induction and maintenance, and 3/both. Our primary objective was the impact of gammaglobulin decline on the risk of relapse and severe infections. RESULTS: We included 98 patients. Patients with gammaglobulin level <6 g/L after induction and gammaglobulin decline >25 % were older (OR 3.9; 95%CI 1.1-16.1), had more frequently baseline gammaglobulin levels <10 g/L (OR 6.0; 95%CI 1.7-25.8) and received more frequent pulses of methylprednisolone at induction (OR 4.6; 95%CI 1.3-18.5). Severe infection-free survival was significantly poorer in patients with both gammaglobulin <6 g/L and gammaglobulin decline >25 % (adjusted HR 2.3; 95%CI 1.0-5.1) and in those who received pulses of methylprednisolone (HR 5.6; 95%CI 2.3-13.4). Gammaglobulin decline was in contrast not associated with the risk of relapse. CONCLUSION: Older age, low gammaglobulin levels and pulses of methylprednisolone at induction increase the likelihood of gammaglobulin decline after induction therapy. Such decline was associated with an increased risk of severe infections but not lower risk of vasculitis relapse. Pulses of methylprednisolone at induction had an independent negative impact on gammaglobulin levels and the risk of severe infections.

Prediction of severe infections in chronic lymphocytic leukemia: a simple risk score to stratify patients at diagnosis.

Chronic Lymphocytic Leukemia (CLL) is well-known for increasing susceptibility to infections. Factors such as immune dysregulation, IGHV status, hypogammaglobulinemia, and patient comorbidity and treatment, contribute to higher infection rates and mortality. However, the impact of hypogammaglobulinemia on infection rates is controversial. We aimed to identify clinical and biological parameters linked to the risk of severe infectious events. Additionally, we set up a straightforward risk infection score to stratify CLL patients at diagnosis, thereby enabling the development of suitable infection prevention strategies. We retrospectively evaluated 210 unselected CLL patients diagnosed between 1988 and 2018. This evaluation encompassed demographics, Binet stage, immunoglobulin (Ig) levels, treatment history, comorbidities, and IGHV mutational status at diagnosis. The frequency and severity of infectious events were recorded. Analysis revealed that age, IGHV mutational status, Binet stage, and hypogammaglobulinemia were statistically associated with the Time to First Infection (TTFI) in univariate and multivariate analyses. Using hazard ratios from the multivariate analysis, we finally devised a risk scoring system that integrated age, IGHV mutational status, immunoglobulin levels, and Binet stage to stratify patients at diagnosis based on their specific infection risk. In our cohort, disease progression and infections were the leading cause of death. These findings pointed out the clinical need for a screening process strategic for defining infectious risk at the time of CLL diagnosis, with a significant enhancement in the clinical management of these patients.

Association between serum IgG concentrations and the incidence of infections in patients with chronic lymphocytic leukemia and secondary immunodeficiency under treatment with Privigen.

OBJECTIVE: To investigate the association between serum immunoglobulin G (IgG) concentrations and the incidence of infections in patients with chronic lymphocytic leukemia (CLL) and secondary immunodeficiency receiving treatment with Privigen. MATERIALS AND METHODS: Data was analyzed from a non-interventional study conducted in 31 centers in Germany and 1 in Austria. Adult CLL patients with hypogammaglobulinemia and recurrent infections were allowed to enter the study upon signing informed consent, if a prior decision for treatment with Privigen had been made. All infections requiring an antimicrobial treatment were subject to analysis. Patients were stratified according to their mean post-baseline serum IgG trough levels in a group with lower IgG trough levels (≤ 5.0 g/L), and a group with higher IgG trough levels (> 5.0 g/L). RESULTS: Overall, 89 patients and 840 treatment cycles were analyzed. Up to 11 treatment cycles (average duration 29 days) were documented in each patient. In the group with higher IgG trough levels (> 5.0 g/L, N = 72), significantly fewer infections were observed than in the group with lower IgG trough levels (≤ 5.0 g/L, N = 17), including fewer severe and serious infections. The Privigen dosage was a major determinant of the post-baseline serum IgG levels. Overall tolerability of Privigen was assessed as very good or good in 91% of patients. CONCLUSION: This analysis confirms the association of serum IgG trough levels with the incidence of infections and highlights the importance of careful monitoring of IgG levels during treatment of secondary immunodeficiencies in CLL patients.

A Nationwide Study of the Delayed Diagnosis and the Clinical Manifestations of Predominantly Antibody Deficiencies and CTLA4-Mediated Immune Dysregulation Syndrome in Greece.

Background and Objectives: Predominantly antibody deficiencies (PAD) represent the most common type of primary immunodeficiencies in humans, characterized by a wide variation in disease onset, clinical manifestations, and outcome. Considering that the prevalence of PAD in Greece is unknown, and there is limited knowledge on the clinical and laboratory characteristics of affected patients, we conducted a nationwide study. Materials and Methods: 153 patients (male/female: 66/87; median age: 43.0 years; range: 7.0-77.0) diagnosed, and followed-up between August 1979 to September 2023. Furthermore, we classified our cohort into five groups according to their medical history, immunoglobulin levels, and CTLA4-mutational status: 123 had common variable immunodeficiency (CVID), 12 patients with "secondary" hypogammaglobulinemia due to a previous B-cell depletion immunotherapy for autoimmune or malignant disease several years ago (median: 9 years, range 6-14) displaying a typical CVID phenotype, 7 with combined IgA and IgG subclass deficiencies, 5 patients with CVID-like disease due to CTLA4-mediated immune dysregulation syndrome, and 6 patients with unclassified hypogammaglobulinemia. Results: We demonstrated a remarkable delay in PAD diagnosis, several years after the onset of related symptoms (median: 9.0 years, range: 0-43.0). A family history of PAD was only present in 11.8%, with the majority of patients considered sporadic cases. Most patients were diagnosed in the context of a diagnostic work-up for recurrent infections, or recurrent/resistant autoimmune cytopenias. Interestingly, 10 patients (5.6%) had no history of infection, diagnosed due to either recurrent/resistant autoimmunity, or during a work-up of their medical/family history. Remarkable findings included an increased prevalence of lymphoproliferation (60.1%), while 39 patients (25.5%) developed bronchiectasis, and 16 (10.5%) granulomatous disease. Cancer was a common complication in our cohort (25 patients, 16.3%), with B-cell malignancies representing the most common neoplasms (56.7%). Conclusion: Our findings indicate the necessity of awareness about PAD and their complications, aiming for early diagnosis and the appropriate management of affected patients.

A Registry Study of 240 Patients with X-Linked Agammaglobulinemia Living in the USA.

PURPOSE: To understand the natural history and clinical outcomes for patients with X-linked agammaglobulinemia (XLA) in the United States utilizing the United States Immunodeficiency Network (USIDNET) patient registry. METHODS: The USIDNET registry was queried for data from XLA patients collected from 1981 to 2019. Data fields included demographics, clinical features before and after diagnosis of XLA, family history, genetic mutation in Bruton's tyrosine kinase (BTK), laboratory findings, treatment modalities, and mortality. RESULTS: Data compiled through the USIDNET registry on 240 patients were analyzed. Patient year of birth ranged from 1945 to 2017. Living status was available for 178 patients; 158/178 (88.8%) were alive. Race was reported for 204 patients as follows: White, 148 (72.5%); Black/African American, 23 (11.2%); Hispanic, 20 (9.8%); Asian or Pacific Islander, 6 (2.9%), and other or more than one race, 7 (3.4%). The median age at last entry, age at disease onset, age at diagnosis, and length of time with XLA diagnosis was 15 [range (r) = 1-52 years], 0.8 [r = birth-22.3 years], 2 [r = birth-29 years], and 10 [r = 1-56 years] years respectively. One hundred and forty-one patients (58.7%) were < 18 years of age. Two hundred and twenty-one (92%) patients were receiving IgG replacement (IgGR), 58 (24%) were on prophylactic antibiotics, and 19 (7.9%) were on immunomodulatory drugs. Eighty-six (35.9%) patients had undergone surgical procedures, two had undergone hematopoietic cell transplantation, and two required liver transplantation. The respiratory tract was the most affected organ system (51.2% of patients) followed by gastrointestinal (40%), neurological (35.4%), and musculoskeletal (28.3%). Infections were common both before and after diagnosis, despite IgGR therapy. Bacteremia/sepsis and meningitis were reported more frequently before XLA diagnosis while encephalitis was more commonly reported after diagnosis. Twenty patients had died (11.2%). The median age of death was 21 years (range = 3-56.7 years). Neurologic condition was the most common underlying co-morbidity for those XLA patients who died. CONCLUSIONS: Current therapies for XLA patients reduce early mortality, but patients continue to experience complications that impact organ function. With improved life expectancy, more efforts will be required to improve post-diagnosis organ dysfunction and quality of life. Neurologic manifestations are an important co-morbidity associated with mortality and not yet clearly fully understood.

Associations between Antiepileptic Use and Hypogammaglobulinaemia: Findings from a Population-Based Case-Control Study Using Data Linkage.

BACKGROUND AND OBJECTIVES: Increased mortality in epilepsy due to infections (other than pneumonia) has been demonstrated. Small case series of people on antiepileptic drugs (AEDs) have described hypogammaglobulinaemia, which may predispose to infections. It is unclear whether hypogammaglobulinaemia is more frequent in people on AEDs, what AEDs it is associated with, or what clinical impact it has. In this population-based study, we aimed to determine whether AEDs were associated with hypogammaglobulinaemia, which AEDs were associated, and whether the associations may be causal. METHODS: We conducted an unmatched case-control study using data linkage of routinely collected biochemistry, prescribing, and morbidity datasets in North-East Scotland from 2009-2021. Cases were participants with immunoglobulin levels less than the reference range. Controls were those with normal/high immunoglobulin levels. Logistic regression was used to investigate associations between AED exposure and any hypogammaglobulinaemia, adjusting for age, sex, and comorbidity. We also analysed low IgA, IgM, and IgG separately. We analysed "any AED" exposure and common individual drugs separately. Cumulative exposure data were used to determine whether an exposure-response relationship was present. RESULTS: 18,666 cases and 127,157 controls were identified. Use of any AED was associated with increased risk of hypogammaglobulinaemia (adjusted odds ratio [aOR] 1.20 [95% CI: 1.15-1.25]). Phenytoin use was strongly associated with low IgA (aOR 5.90 [95% CI: 3.04, 10.43]). Carbamazepine and lamotrigine were also associated with low IgA. Apart from topiramate, which was associated with a non-significant decrease in odds of hypogammaglobulinaemia, there was a consistent increase in odds of hypogammaglobulinaemia across most AEDs studied. Panhypogammaglobulinaemia was associated with any AED use, carbamazepine, lamotrigine, gabapentin, and multiple AED use. There was evidence of an exposure-response relationship between any AED use and any hypogammaglobulinaemia, low IgA, and low IgG. Carbamazepine and probably lamotrigine also had an exposure-response relationship with any hypogammaglobulinaemia. DISCUSSION: AEDs may increase hypogammaglobulinaemia risk. Specific classes of immunoglobulins are differentially affected, and the exposure-response analysis suggests this may be causal. Further work should investigate the clinical impact of these findings. Clinicians should check immunoglobulin levels if unusual or recurrent infections occur in patients treated with AEDs.

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.

Rituximab-associated hypogammaglobulinemia in children with idiopathic nephrotic syndrome: results of an ESPN survey.

BACKGROUND: There is paucity of information on rituximab-associated hypogammaglobulinemia (HGG) and its potential infectious consequences in children treated for idiopathic nephrotic syndrome (INS). METHODS: A survey was distributed by the European Society Pediatric Nephrology to its members. It addressed the screening and management practices of pediatric nephrology units for recognizing and treating RTX-associated HGG and its morbidity and mortality. Eighty-four centers which had treated an overall 1328 INS children with RTX responded. RESULTS: The majority of centers administered several courses of RTX and continued concomitant immunosuppressive therapy. Sixty-five percent of centers routinely screened children for HGG prior to RTX infusion, 59% during, and 52% following RTX treatment. Forty-seven percent had observed HGG prior to RTX administration, 61% during and 47% >9 months following treatment in 121, 210, and 128 subjects respectively. Thirty-three severe infections were reported among the cohort of 1328 RTX-treated subjects, of whom 3 children died. HGG had been recognized in 30/33 (80%) of them. CONCLUSIONS: HGG in steroid-dependent/frequently relapsing nephrotic syndrome (SDNS/FRNS) children is probably multifactorial and can be observed prior to RTX administration in children with SDNS/FRNS. Persistent HGG lasting >9 months from RTX infusion is not uncommon and may increase the risk of severe infections in this cohort. We advocate for the obligatory screening for HGG in children with SDNS/FRNS prior to, during, and following RTX treatment. Further research is necessary to identify risk factors for developing both HGG and severe infections before recommendations are made for its optimal management. A higher resolution version of the Graphical abstract is available as Supplementary information.

Hypogammaglobulinemia after front-line immunochemotherapy in patients with follicular lymphoma.

INTRODUCTION: Hypogammaglobulinemia after front-line immunochemotherapy for follicular lymphoma is a poorly studied adverse event that could be related to the appearance of severe and/or recurrent non-neutropenic infections which could affect the quality of life of the patients, even motivating a need of long-term replacement therapy with human immunoglobulins. METHODS: Observational, retrospective study aiming to estimate the incidence of hypogammaglobulinemia, as well as its severity and clinical consequences, and to explore possible predictive factors for its development. Specific immunoglobulin deficiencies were also studied. RESULTS: 76.5% of patients had hypogammaglobulinemia during or after front-line treatment, mostly grade 1-2; with 38.8% patients who developed clinically relevant infections and 20% patients requiring human immunoglobulins replacement therapy. A high-risk FLIPI score was identified as a risk factor for hypogammaglobulinemia (ods ratio: 4.51; 95% confidence interval: 1.29-15.68; p < 0.001) and basal gamma globulin level as a protective factor (odds ratio: 0.92; 95% confidence interval: 0.988-0.996; p = 0.018). Any type of immunochemotherapy regimen was associated with different risks of hypogammaglobulinemia in our study. CONCLUSIONS: Hypogammaglobulinemia appears in a high percentage of patients with follicular lymphoma in a real-world population, identifying a high-risk FLIPI score as a risk factor for its development and basal gamma globulins as a protective factor.

Algerian Registry for Inborn Errors of Immunity in Children: Report of 887 Children (1985-2021).

INTRODUCTION: Inborn errors of immunity (IEI) represent a heterogeneous large group of genetic disorders characterized by susceptibility of affected individuals to recurrent infections, autoimmune/inflammatory diseases, allergy, and malignancy. We aimed to report for the first time the Algerian registry for IEI in children. METHODS: We described the characteristics of IEI in Algerian children from the data collected in the Algerian registry for IEI between 1985 and 2021. RESULTS: Over a period of 37 years, we included 887 children (530 male, 59.6%) with a mean age at diagnosis of 3.23 years and a mean diagnosis delay of 2 years. The prevalence rate was estimated at 1.97/100,000 inhabitants or 5.91/100,000 children. The parental consanguinity was found in 52.6%. The most prevalent category was combined immunodeficiencies (CID) (35.5%), followed by predominantly antibody deficiencies (24.5%) and CID with syndromic features (18.3%). The most predominant diseases were severe CID (134 cases), MHC II deficiency (99 cases), agammaglobulinemia (82 cases), common variable immunodeficiency (78 cases), hyper IgE syndromes (61 patients), ataxia-telangiectasia (46 patients), Wiskott-Aldrich syndrome (40 patients) and chronic granulomatous disease (39 cases). The clinical presentation was dominated by lower respiratory tract infections (69%), failure to thrive (38.3%), and chronic diarrhea (35.2%). Genetic analysis was performed in 156 patients (17.6%). The global mortality rate was 28.4% mainly caused by CID. CONCLUSION: This is the first report of the Algerian registry for IEI in children. Data is globally similar to that of the Middle East and North African (MENA) registries with high consanguinity, predominance of CID, and significant mortality. This registry highlights the weak points that should be improved in order to provide better patient care.

X-Linked Agammaglobulinemia: Infection Frequency and Infection-Related Mortality in the USIDNET Registry.

X-linked agammaglobulinemia (XLA) is a primary immunodeficiency disorder caused by mutations in the Bruton tyrosine kinase (BTK) gene leading to B lymphocyte deficiency and susceptibility to infection. A potential benefit of earlier diagnosis and treatment initiation on morbidity and mortality in XLA is incompletely understood. In the USIDNET Registry, we describe infection frequency and infection-related mortality in patients with XLA and their relationship to age of diagnosis and treatment initiation. Among the 231 XLA patients enrolled in the Registry, respiratory infections (N = 203, 88%) were the most commonly reported. Among those deceased (N = 20) where cause of death was known (N = 17), mortality was attributed to infection in most (N = 12, 71%). Chronic lung disease, often a consequence of repeated lower respiratory tract infection (LRTI), was also a frequent complication associated with mortality (N = 9, 53%). Age of diagnosis in years was lower for those without LRTI compared to those with (median 1.5 [IQR 0.5-3.3] vs. median 3.0 [IQR 1.0-5.0], p = 0.0026) and among living patients compared to deceased (median 1.8 [IQR 0.5-5.0] vs. median 2.7 [IQR 1.6-6.0], p = 0.04). Age at treatment initiation in years was lower among those without LRTIs compared to those with (median 1.0 [IQR 0.4-2.4] vs. median 2.8 [IQR 1.0-5.4], p = 0.0006). For every year increase in age at start of therapy, the odds of experiencing a LRTI was 1.216 (OR 1.216, 95% CI 1.048-1.411, p = 0.01). Given the expected finding of reduced LRTIs and mortality among those with earlier age at diagnosis, our study findings support inclusion of XLA in newborn screening programs.

New-onset hypogammaglobulinaemia and infectious complications associated with rituximab use in childhood-onset rheumatic diseases.

OBJECTIVE: To investigate the incidence and risk factors for hypogammaglobulinaemia and infectious complications associated with rituximab treatment in childhood-onset rheumatic diseases. METHODS: We performed a single-centre retrospective study of patients (n = 85) treated at Boston Children's Hospital (BCH) from 2009 to 2019. Study subjects included patients (ages 6-24 years) who received rituximab for the treatment of a childhood-onset rheumatic disease. RESULTS: New-onset hypogammaglobulinaemia developed in 23 (27.1%) patients within 18 months of rituximab induction treatment. Twenty-two patients (25.9%) developed at least one infectious complication in the 18 months following the first rituximab infusion; of these, 11 (50%) had serious infections requiring inpatient treatment. After adjusting for potential confounders, exposure to pulse corticosteroid therapy in the month prior to rituximab use was a significant predictor of both new-onset hypogammaglobulinaemia (odds ratio [OR] 3.94; 95% CI: 1.07, 16.0; P = 0.044) and infectious complications (OR 15.3; 95% CI: 3.04, 126.8; P = 0.003). Post-rituximab hypogammaglobulinaemia was the strongest predictor of serious infectious complications (OR 7.89; 95% CI: 1.41, 65.6; P = 0.028). Younger age at rituximab use was also a significant predictor of new-onset hypogammaglobulinaemia (OR 0.83; 95% CI: 0.70, 0.97; P = 0.021). Compared with other rheumatic diseases, patients with vasculitis had a higher likelihood of developing infectious complications, including serious infections. CONCLUSION: Although rituximab was well tolerated in terms of infectious complications in the majority of patients with childhood-onset rheumatic diseases, a substantial proportion developed new-onset hypogammaglobulinaemia and infectious complications following treatment. Our study highlights a role for heightened vigilance of rituximab-associated hypogammaglobulinaemia and infections in paediatric patients with rheumatic conditions.

Incidence and risk factors of rituximab-associated hypogammaglobulinemia in patients with complicated nephrotic syndrome.

BACKGROUND: Hypogammaglobulinemia is a major adverse event after rituximab treatment; however, the precise incidence and risk factors are unclear in complicated steroid-dependent or frequently relapsing nephrotic syndrome (SDNS/FRNS) patients. METHODS: This was a single-center, retrospective, observational study. Patients who received a single dose of rituximab for complicated SDNS or FRNS between February 2007 and May 2019 were enrolled. Serum IgG levels were plotted, and their trends were evaluated after rituximab treatment. The incidence of transient and persistent hypogammaglobulinemia was examined, and risk factors were calculated by multivariate analysis using logistic regression. RESULTS: We enrolled 103 patients who received 238 single doses of rituximab. Hypogammaglobulinemia was observed in 58.4% of the patients at least once after a single dose of rituximab treatment and 22.3% developed persistent hypogammaglobulinemia. Serum IgG levels gradually increased during B-cell depletion, and patients with low serum IgG levels at rituximab treatment had persistent hypogammaglobulinemia. Repeated courses of rituximab treatment increased the incidence of hypogammaglobulinemia. A past history of steroid-resistant nephrotic syndrome (SRNS) (odds ratio [OR] = 10.02; 95% confidence interval [CI] = 2.65-37.81; P < 0.001) and low serum IgG levels at rituximab treatment (OR = 7.63; 95% CI = 2.10-27.71; P = 0.002) was significantly associated with hypogammaglobulinemia in multivariate analysis. CONCLUSIONS: Hypogammaglobulinemia is a frequent adverse event after rituximab treatment, although IgG levels slightly increase during B-cell depletion. Low serum IgG levels at rituximab treatment and a past history of SRNS are significant risk factors for the development of hypogammaglobulinemia after rituximab treatment.

Rituximab-induced hypogammaglobulinemia and infection risk in pediatric patients.

BACKGROUND: Rituximab is a B-cell depleting agent used in B-cell malignancies and autoimmune diseases. A subset of adult patients may develop prolonged and symptomatic hypogammaglobulinemia following rituximab treatment. However, this phenomenon has not been well delineated in the pediatric population. OBJECTIVES: This study sought to determine the prevalence, risk factors, and clinical significance of hypogammaglobulinemia following rituximab therapy in children. METHODS: This was a multicenter, retrospective cohort study that extracted clinical and immunological data from pediatric patients who received rituximab. RESULTS: The cohort comprised 207 patients (median age, 12.0 years). Compared to baseline values, there was a significant increase in hypogammaglobulinemia post-rituximab therapy, with an increase in prevalence of hypo-IgG (28.7%-42.6%; P = .009), hypo-IgA (11.1%-20.4%; P = .02), and hypo-IgM (20.0%-62.0%; P < .0001). Additionally, low IgG levels at any time post-rituximab therapy were associated with a higher risk of serious infections (34.4% vs 18.9%; odds ratio, 2.3; 95% CI, 1.1-4.8; P = .03). Persistent IgG hypogammaglobulinemia was observed in 27 of 101 evaluable patients (26.7%). Significant risk factors for persistent IgG hypogammaglobulinemia included low IgG and IgA levels pre-rituximab therapy. Nine patients (4.3%) within the study were subsequently diagnosed with a primary immunodeficiency, 7 of which received rituximab for autoimmune cytopenias. CONCLUSIONS: Hypogammaglobulinemia post-rituximab treatment is frequently diagnosed within the pediatric population. Low IgG levels are associated with a significant increase in serious infections, and underlying primary immunodeficiencies are relatively common in children receiving rituximab, thus highlighting the importance of immunologic monitoring both before and after rituximab therapy.

Seasonal Influenza Vaccine: Uptake, Attitude, and Knowledge Among Patients Receiving Immunoglobulin Replacement Therapy.

Influenza is a potential cause of severe disease in the immunocompromised. Patients with hypogammaglobulinemia, in spite of adequate replacement therapy, are at risk of significant morbidity and adverse outcomes. A seasonal vaccine is the primary prophylactic countermeasure to limit disease. The aim of this study was to evaluate the attitude, knowledge, and influenza vaccine uptake among Irish patients receiving immunoglobulin replacement therapy (IgRT), as well as uptake in co-habitants. Fifty-seven percent of patients receiving IgRT at a regional immunology referral center completed a questionnaire evaluation. Seventy-six percent of IgRT patients received the influenza vaccine for the 2019 season. Ninety-eight percent recognized that influenza could be prevented with vaccination, and 81% deemed it a safe treatment. Ninety-three percent correctly identified that having a chronic medical condition, independent of age, was an indication for vaccination. Despite excellent compliance and knowledge, many were not aware that vaccination was recommended for co-habitants, and only 24% had full vaccine coverage at home. Those who received advice regarding vaccination of household members had higher rates of uptake at home. This study demonstrates awareness and adherence to seasonal influenza vaccine recommendations among patients receiving IgRT. Over three quarters felt adequately informed, the majority stating physicians as their information source. We identified an easily modifiable knowledge gap regarding vaccination of household members. This data reveals a need to emphasize the importance of vaccination for close contacts of at-risk patients, to maintain optimal immunity and health outcome.

Hypogammaglobulinemia after rituximab for rheumatoid arthritis is not rare and is related with good response: 13 years real-life experience.

OBJECTIVES: Rituximab (RTX) use in the treatment of RA can be complicated by decrease in IgG, IgM or IgA levels (hypogammaglobulinemia-HGG). The aim of this study was to define the frequency of HGG in RA patients treated with RTX and to identify associations between its occurrence and patients' characteristics, disease outcomes and serious infections rate. METHODS: RA patients treated with RTX in two rheumatology centers from January 2007 to January 2020 were retrospectively examined. Demographical, clinical and laboratory parameters were recorded at baseline and at last visit. RESULTS: Eighty-three patients (84.3% females) with a mean age of 63.2 years were enrolled. They had baseline DAS28(CRP) of 5.2 (1.1) and received a median (range) of 8 (2-20) RTX cycles. A total of 43.4%, 24.1% and 31.3% developed 'any HGG', 'low IgG' and 'low IgM', respectively. Lower baseline IgG and IgM levels were predictors of 'low IgG' and 'low IgM' occurrence, respectively. Patients who developed 'low IgM' exhibited lower DAS28(CRP) and increased rates of remission and low disease activity compared with those with normal IgM levels. Patients who maintained normal IgG were receiving methotrexate more frequently. No differences were observed in serious infections rate among subgroups. CONCLUSION: HGG occurred in 43% of RTX-treated patients. Patients who developed low IgG or low IgM had lower baseline levels than those who did not. Concomitant DMARD and corticosteroid therapy was not associated with HGG. Low IgM, but not low IgG, development was associated with better disease outcomes. HGG was not associated with an increased incidence of serious infections.

Secondary Immunodeficiency and Hypogammaglobulinemia with IgG Levels of <5 g/L in Patients with Multiple Myeloma: A Retrospective Study Between 2012 and 2020 at a University Hospital in China.

BACKGROUND Infections are the main cause of mortality and morbidity in multiple myeloma (MM) patients. However, adult immunodeficiency specialists in China are lacking, and the care of secondary immunodeficiency (SID) and the prognostic role of hypogammaglobulinemia in MM is unknown. MATERIAL AND METHODS MM patients (295) were retrospectively analyzed between January 2012 and 2020 in Zhejiang Provincial People's Hospital, Hangzhou Medical College. MM patients with immunoglobulin (Ig) G <5 g/L were defined as SID patients. The care of these patients and the prognostic role of IgG <5 g/L were analyzed RESULTS Forty-five of 295 MM patients with IgG <5 g/L were defined as SID patients. These 45 patients mainly had recurrent infections, especially pulmonary bacterial infections; 2 patients had them 5 times/year. The median survival time was significantly shorter in MM patients with SID (24 vs 66 months). More importantly, the multivariate and univariate analysis revealed that IgG <5 g/L was an independent prognostic factor for MM patients. CONCLUSIONS Ig replacement therapy or prophylactic antibiotics for MM patients with SID were lacking in this single retrospective study. IgG <5 g/L could be a prognostic marker for MM patients.

Long-term follow-up of 168 patients with X-linked agammaglobulinemia reveals increased morbidity and mortality.

BACKGROUND: X-linked agammaglobulinemia (XLA) is the prototype of primary humoral immunodeficiencies. Long-term follow-up studies regarding disease-related complications and outcome are scarce. OBJECTIVE: Our aim was to describe the natural history of XLA. METHODS: A nationwide multicenter study based on the Italian Primary Immunodeficiency Network registry was established in 2000 in Italy. Affected patients were enrolled by documenting centers, and the patients' laboratory, clinical, and imaging data were recorded on an annual base. RESULTS: Data on the patients (N = 168) were derived from a cumulative follow-up of 1370 patient-years, with a mean follow-up of 8.35 years per patient. The mean age at diagnosis decreased after establishment of the Italian Primary Immunodeficiency Network registry (84 months before vs 23 months after). Respiratory, skin, and gastrointestinal manifestations were the most frequent clinical symptoms at diagnosis and during long-term follow-up. Regular immunoglobulin replacement treatment reduced the incidence of invasive infections. Affected patients developed chronic lung disease over time (47% after 40 years of follow-up) in the presence of chronic sinusitis (84%). Malignancies were documented in a minority of cases (3.7%). Overall survival for affected patients was significantly reduced when compared with that for the healthy male Italian population, and it further deteriorated in the presence of chronic lung disease. CONCLUSIONS: This is the first detailed long-term follow-up study for patients with XLA, revealing that although immunoglobulin replacement treatment reduces the incidence of invasive infections, it does not appear to influence the development of chronic lung disease. The overall survival of affected patients is reduced. Further studies are warranted to improve patients' clinical management and increase awareness among physicians.

Morbidity in an adenosine deaminase-deficient patient during 27 years of enzyme replacement therapy.

INTRODUCTION: Adenosine deaminase (ADA) deficiency causes severe immunodeficiency that is lethal in infancy. Enzyme replacement therapy (ERT) can improve the metabolic, immune and non-immune abnormalities in patients prior to transplantation, however, its benefits over extended periods are not well characterized. We describe a 28-year-old female who received ERT for 27 years. She suffered from EBV negative B cell lymphoma of the hip at 14 years of age and Guillian-Barre Syndrome 2 years later. At 22 years of age, she experienced a gastrointestinal infection with Mycobacterium genavense. At 26 years of age, lymphoma reoccurred with multiple liver lesions followed by Mycobacterium genavense infection with dissemination to the brain. Throughout this period, ADA activity in the plasma was within the therapeutic range. Repeated evaluations demonstrated very low lymphocyte counts and impaired T cell function. CONCLUSIONS: ERT might be insufficient to maintain normal immunity over extended periods in some ADA-deficient patients.

Evaluation of respiratory complications in patients with X-linked and autosomal recessive agammaglobulinemia.

BACKGROUND: Congenital agammaglobulinemia is the first primary immunodeficiency disorder characterized by a defect in B lymphocyte development and subsequently decreased immunoglobulin levels. These patients are prone to suffer from recurrent infections mostly involving the respiratory tract. In this study, we aimed to describe in detail respiratory tract complications as the most prominent clinical feature among agammaglobulinemic patients. METHODS: A total number of 115 patients were included. Demographic, clinical, and genetic data were collected from the patients' medical records. Among the available patients, pulmonary function tests (PFTs) and/or high-resolution computed tomography (HRCT) were performed. RESULTS: Respiratory tract complications (85.2%) especially pneumonia (62.6%) were the most prominent clinical features in our cohort. Among patients with abnormal PFT results (N = 19), a mixed respiratory pattern was observed in 36.8%. HRCT was carried out in 29 patients; Bhalla scoring-based evaluation of these patients indicated excellent (44.8%), followed by good (34.5%) and mild (20.7%) results. Bronchiectasis was found in 13 patients undergoing HRCT (44.8%). We found significant inverse correlations between the Bhalla score and incidence rate of pneumonia, as well as the presence of bronchiectasis. Patients with abnormal PFT results had statistically significant higher bronchiectasis frequency and lower Bhalla scores compared to those with normal results. Forty-one patients were deceased, and here, respiratory failure was the most common cause of death (45.5%). CONCLUSION: High prevalence of respiratory tract infections among agammaglobulinemic patients and subsequent progression to permanent lung damage highlights the importance of implementing respiratory evaluation as part of routine follow-up program of agammaglobulinemic patients. Physicians should be aware of this and regularly monitor the respiratory function of these patients to allow for timely diagnosis and treatment initiation aiming to improve patients' prognosis and quality of life.