Treatment of hypogammaglobulinemia in adults: a scoring system to guide decisions on immunoglobulin replacement

A stepwise approach to the adult immunodeficiency evaluation for the rhinologist

PURPOSE OF REVIEW

Patients with an immunodeficiency may present to their Rhinologist with a history of recurrent, severe, and chronic infections. Therefore, it is essential for the Rhinologist to have a basic understanding of clinically relevant immune deficiencies.

RECENT FINDINGS

After describing different types of immunodeficiencies, their presentations, and management strategies, an evaluation algorithm is described.

SUMMARY

Through a collaborative approach, Rhinologists and Clinical Immunologists can provide comprehensive medical care to patients with immunodeficiencies.

Secondary hypogammaglobulinemia in patients with multiple sclerosis on anti-CD20 therapy: Pathogenesis, risk of infection, and disease management

Hypogammaglobulinemia is characterized by reduced serum immunoglobulin levels. Secondary hypogammaglobulinemia is of considerable interest to the practicing physician because it is a potential complication of some medications and may predispose patients to serious infections. Patients with multiple sclerosis (MS) treated with B-cell-depleting anti-CD20 therapies are particularly at risk of developing hypogammaglobulinemia. Among these patients, hypogammaglobulinemia has been associated with an increased risk of infections. The mechanism by which hypogammaglobulinemia arises with anti-CD20 therapies (ocrelizumab, ofatumumab, ublituximab, rituximab) remains unclear and does not appear to be simply due to the reduction in circulating B-cell levels. Further, despite the association between anti-CD20 therapies, hypogammaglobulinemia, and infections, there is currently no generally accepted monitoring and treatment approach among clinicians treating patients with MS. Here, we review the literature and discuss possible mechanisms of secondary hypogammaglobulinemia in patients with MS, hypogammaglobulinemia results in MS anti-CD20 therapy clinical trials, the risk of infection for patients with hypogammaglobulinemia, and possible strategies for disease management. We also include a suggested best-practice approach to specifically address secondary hypogammaglobulinemia in patients with MS treated with anti-CD20 therapies.

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 Immune Deficiency and Dysregulation Activity (IDDA2.1 'Kaleidoscope') Score and Other Clinical Measures in Inborn Errors of Immunity

Quantifying the phenotypic features of rare diseases such as inborn errors of immunity (IEI) helps clinicians make diagnoses, classify disorders, and objectify the disease severity at its first presentation as well as during therapy and follow-up. Furthermore, it may allow cross-sectional and cohort comparisons and support treatment decisions such as an evaluation for transplantation. On the basis of a literature review, we provide a descriptive comparison of ten selected scores and measures frequently used in IEI and divide these into three categories: (1) diagnostic tools (for Hyper-IgE syndrome, hemophagocytic lymphohistiocytosis, and Wiskott-Aldrich syndrome), (2) morbidity and disease activity measures (for common variable immune deficiency [CVID], profound combined immune deficiency, CTLA-4 haploinsufficiency, immune deficiency and dysregulation activity [IDDA], IPEX organ impairment, and the autoinflammatory disease activity index), and (3) treatment stratification scores (shown for hypogammaglobulinemia). The depth of preclinical and statistical validations varies among the presented tools, and disease-inherent and user-dependent factors complicate their broader application. To support a comparable, standardized evaluation for prospective monitoring of diseases with immune dysregulation, we propose the IDDA2.1 score (comprising 22 parameters on a 2–5-step scale) as a simple yet comprehensive and powerful tool. Originally developed for use in a retrospective study in LRBA deficiency, this new version may be applied to all IEI with immune dysregulation. Reviewing published aggregate cohort data from hundreds of patients, the IDDA kaleidoscope function is presented for 18 exemplary IEI as an instructive phenotype–pattern visualization tool, and an unsupervised, hierarchically clustered heatmap mathematically confirms similarities and differences in their phenotype expression profiles.

Variable immunodeficiency score upfront analytical link (VISUAL), a proposal for combined prognostic score at diagnosis of common variable immunodeficiency

The broad and heterogeneous clinical spectrum that characterizes common variable immunodeficiency (CVID) is associated with quite different disease course and prognosis, highlighting the need to develop tools that predict complications. We developed a multianalyte VISUAL score (variable immunodeficiency score upfront analytical link) aimed to predict severity using individual CVID patient data at baseline of a cohort of 50 CVID patients from two different centers in Portugal and Spain. We retrospectively applied VISUAL to the CVID clinical severity scores proposed by Ameratunga and Grimbacher after 15 years follow-up of our cohort. VISUAL score at CVID diagnosis showed adequate performance for predicting infectious and non-infectious severe complications (Cluster B). Compared to switched memory B lymphocyte phenotype alone, VISUAL provided a more accurate identification of clinically meaningful outcome, with significantly higher sensitivity (85% vs 55%, p = 0.01), and negative predictive value (77% vs 58%) and AUC of the ROC curves (0.72 vs 0.64), with optimal cut-off level of 10. For every increase of 1 point in the VISUAL scale, the odds of being in the higher risk category (Cluster B) increased in 1.3 (p = 0.005) for Ameratunga's severity score and 1.26 (p = 0.004) for Grimbacher's severity score. At diagnosis of CVID, VISUAL score ≥ 10 showed 8.94-fold higher odds of severe prognosis than below this threshold. Kaplan-Meier estimates for the VISUAL ≥ 10 points showed significantly earlier progression to Cluster B than those with VISUAL < 10 (p = 0.0002). This prognostic laboratory score might allow close monitoring and more aggressive treatment in patients with scores ≥ 10 on a personalized basis approach. Further studies are needed to prospectively validate VISUAL score.

Perspective: Evolving Concepts in the Diagnosis and Understanding of Common Variable Immunodeficiency Disorders (CVID)

Common variable immunodeficiency disorders (CVID) are the most frequent symptomatic primary immune deficiency in adults. At this time, the causes of these conditions are unknown. Patients with CVID experience immune system failure consequent to late onset antibody failure. They have increased susceptibility to infections and are also at risk of severe autoimmune and inflammatory disorders as a result of immune dysregulation. An increasing number of monogenic causes as well as a digenic disorder have been described in patients with a CVID phenotype. If a causative mutation is identified, patients are removed from the umbrella diagnosis of CVID and are reclassified as having a CVID-like disorder, resulting from a specific mutation. In non-consanguineous populations, next-generation sequencing (NGS) identifies a genetic cause in approximately 25% of patients with a CVID phenotype. It is six years since we published our diagnostic criteria for CVID. There is ongoing debate about diagnostic criteria, the role of vaccine responses and genetic analysis in the diagnosis of CVID. There have been several recent studies, which have addressed some of these uncertainties. Here we review this new evidence from the perspective of our CVID diagnostic criteria and speculate on future approaches, which may assist in identifying and assessing this group of enigmatic disorders.

Variable immunodeficiency study: Evaluation of two European cohorts within a variety of clinical phenotypes

INTRODUCTION

Given the wide heterogeneity of common variable immunodeficiency (CVID), several groups have proposed clinical and immunological classifications to better define follow-up and prognostic algorithms. The present study aims to validate recent clinical and laboratory algorithms, based on different combinations of CVID biomarkers, to provide more personalized treatment and follow-up strategies.

METHODS

We analysed clinical and immunological features of 80 patients with suspected or diagnosed CVID, in two reference centres of Portugal and Spain. Clinical manifestations were categorized into clinical phenotyping proposed by Chapel et al. [1] that included cytopenia; polyclonal lymphocytic infiltration; unexplained enteropathy; and no disease-related complications.

RESULTS

76% of patients in our cohort entered one of the four categories of clinical phenotyping, without overlap (cytopenia; polyclonal lymphocytic infiltration; unexplained enteropathy; and no disease-related complications). The most prominent phenotype was "cytopenia" (40%) followed by "polyclonal lymphocytic infiltration" (19%). The remaining 24% patients of our cohort had overlap of 2 clinical phenotypes (cytopenia and unexplained enteropathy mainly). A delay of CVID diagnosis in more than 6 years presented 3.7-fold higher risk of developing lymphoproliferation and/or malignancy (p < 0.05), and was associated with increased CD8⁺CD45RO ⁺ T-lymphocytes (p < 0.05). An association between decreased switched-memory B cells with lymphoproliferation and malignancy was observed (p < 0.03 and p < 0.05, respectively). CD4 ⁺ T-lymphocytopenia correlated with autoimmune phenotype, with 30% prevalence (p < 0.05). HLA-DR7 expression was related to CVID onset in early life in our patients (13 vs 25 years), and DQ2.5 or DQ2.2 with unexplained enteropathy (p < 0.05).

CONCLUSIONS

The phenotypic and genetic study is crucial for an adequate clinical orientation of CVID patients. In these two independent cohorts of patients, classification based in clinical and laboratory algorithms, provides more personalized treatment and follow-up strategies.

Birds of a feather: Common variable immune deficiencies

OBJECTIVE

To update the reader on recently proposed common variable immune deficiency (CVID) diagnostic criteria, newly uncovered CVID pathobiology, freshly identified CVID-related genes, and novel CVID therapies.

DATA SOURCES

PubMed Central.

STUDY SELECTIONS

We selected 60 clinical and translational research articles that have shaped CVID diagnostic criteria, introduced personalized therapies, and advanced our understanding of CVID biology and genetics. We have incorporated recent articles and older published work that are foundational to the modern understanding of this protean disease.

RESULTS

CVID has proven to be a heterogenous group of antibody deficiency diseases driven by defects in diverse biologic processes, including B-cell development, activation, tolerance, class-switch recombination, somatic hypermutation, and lymphoproliferation. Recent genetic advances have enabled identification of several CVID-related gene defects that may contribute to patients' infectious and noninfectious symptoms.

CONCLUSION

Improved understanding of the aberrant biologic processes that drive CVID and the disease's genetic basis may be useful in directing therapeutic decisions, especially in cases complicated by autoimmune, lymphoproliferative, and inflammatory features.

Differentiation of Common Variable Immunodeficiency From IgG Deficiency

BACKGROUND

Common variable immunodeficiency (CVID) and IgG deficiency are 2 of the more prevalent primary humoral immune defects. The former is defined by consensus with criteria for quantitative and qualitative antibody defects, whereas the latter is used to describe patients with reduced IgG, who commonly have recurrent sinopulmonary infections but do not fulfill CVID criteria. However, these patients are often given this diagnosis.

OBJECTIVE

To compare immunologic findings and clinical manifestations of 2 large cohorts of patients with CVID or IgG deficiency to better delineate differences between these syndromes.

METHODS

We extracted clinical and laboratory data from electronic medical records of patients at our institution who had received International Classification of Disease codes for either CVID, or IgG deficiency. We gathered immunoglobulin levels, lymphocyte subpopulation counts, and serological vaccine responses. In some patients, we performed flow cytometry to determine percentages of memory and switched-memory B cells. We compiled and statistically compared clinical data related to infectious manifestations, bronchiectasis, autoimmune diseases, infiltrative inflammatory processes, and lymphoid malignancies.

RESULTS

In contrast to IgG-deficient patients, we found that patients with CVID had lower IgG levels, greater unresponsiveness to most vaccines, lower percentages of memory and isotype switched-memory B cells, and lower CD4 T-cell counts. Clinically, patients with CVID presented similar rates of sinusitis and pneumonias, but a significantly higher prevalence of bronchiectasis and especially noninfectious complications.

CONCLUSIONS

CVID and IgG deficiency do not share the same disease spectrum, the former being associated with immunodysregulative manifestations and markers of a more severe immune defect. These data may allow clinicians to distinguish these conditions and the management differences that these patients pose.

Keeping it in the family: the case for considering late-onset combined immunodeficiency a subset of common variable immunodeficiency disorders

INTRODUCTION

Common variable immunodeficiency disorders (CVID) are the most frequent symptomatic primary immune defect in adults. Within the broad spectrum of CVID, a proportion of patients present with a predominant T cell phenotype associated with increased mortality. These patients are termed late-onset combined immunodeficiency (LOCID) and are currently separated from patients suffering from CVID. Areas covered: We have recently codiscovered a new CVID-like disorder caused by mutations of the NFKB1 gene. Members of this non-consanguineous New Zealand kindred have a very diverse spectrum of phenotypes in spite of carrying the identical mutation. The proband appears to have the autoimmune variant. The proband's recently deceased sister best matched LOCID while other family members are less severely affected, including one asymptomatic adult brother, who has an affected daughter. Differences in genetics was one of the main arguments for separating these disorders in the past. Expert commentary: Given the recent advances in the understanding of the genetic basis of these conditions, we present the case that LOCID should now be considered a subset of CVID, rather than a separate disorder. At a clinical level, this distinction is less important but it is imperative these patients are carefully evaluated, the relevant complications are treated, and they are offered prognostic information.

Latent therapeutic demand model for the immunoglobulin replacement therapy of primary immune deficiency disorders in the USA

BACKGROUND AND OBJECTIVES

Our research aim is to model latent therapeutic demand (LTD) for the immunoglobulin replacement therapy (IgGRT) of primary immune deficiency disorders (PIDDs) in the USA. Given the high level of variability of IgGRT use and major differences among American and European practices in the management of patients with PIDDs, we develop a USA-specific LTD model for common variable immune deficiency (CVID), hyper IGM syndrome, severe combined immune deficiency, Wiskott-Aldrich syndrome and X-linked agammaglobulinemia (XLA).

METHODS AND MATERIALS

We use decision analysis methods to model the underlying IgGRT demand for PIDDs by assessing USA-specific epidemiology and treatment. Data for the epidemiology and treatment variables were obtained from the medical literature, USIDNET and Immune Deficiency Foundation. The uncertainty surrounding the variables was modelled using probability distributions and evaluated using Monte Carlo simulation.

RESULTS

The mean treatment dose from USIDNET and European Society for Immunodeficiencies (ESID) was significantly different for treating CVID, and the number of annual infusions from USIDNET and ESID was significantly different for treating CVID and XLA. The mean and standard deviation of LTD for all PIDDs is 105·1 ± 88·5 g per 1000 population, with CVID contributing the most to LTD.

CONCLUSION

Estimating country-specific LTD is important to ensure an adequate supply of IgGRT and an optimal treatment for patients with PIDDs and for improving national healthcare policymaking and production planning.

Clinical Implications of Digenic Inheritance and Epistasis in Primary Immunodeficiency Disorders

The existence of epistasis in humans was first predicted by Bateson in 1909. Epistasis describes the non-linear, synergistic interaction of two or more genetic loci, which can substantially modify disease severity or result in entirely new phenotypes. The concept has remained controversial in human genetics because of the lack of well-characterized examples. In humans, it is only possible to demonstrate epistasis if two or more genes are mutated. In most cases of epistasis, the mutated gene products are likely to be constituents of the same physiological pathway leading to severe disruption of a cellular function such as antibody production. We have recently described a digenic family, who carry mutations of TNFRSF13B/TACI as well as TCF3 genes. Both genes lie in tandem along the immunoglobulin isotype switching and secretion pathway. We have shown they interact in an epistatic way causing severe immunodeficiency and autoimmunity in the digenic proband. With the advent of next generation sequencing, it is likely other families with digenic inheritance will be identified. Since digenic inheritance does not always cause epistasis, we propose an epistasis index which may help quantify the effects of the two mutations. We also discuss the clinical implications of digenic inheritance and epistasis in humans with primary immunodeficiency disorders.

Epistatic interactions between mutations of TACI (TNFRSF13B) and TCF3 result in a severe primary immunodeficiency disorder and systemic lupus erythematosus

Common variable immunodeficiency disorders (CVID) are a group of primary immunodeficiencies where monogenetic causes account for only a fraction of cases. On this evidence, CVID is potentially polygenic and epistatic although there are, as yet, no examples to support this hypothesis. We have identified a non-consanguineous family, who carry the C104R (c.310T>C) mutation of the Transmembrane Activator Calcium-modulator and cyclophilin ligand Interactor (TACI, TNFRSF13B) gene. Variants in TNFRSF13B/TACI are identified in up to 10% of CVID patients, and are associated with, but not solely causative of CVID. The proband is heterozygous for the TNFRSF13B/TACI C104R mutation and meets the Ameratunga et al. diagnostic criteria for CVID and the American College of Rheumatology criteria for systemic lupus erythematosus (SLE). Her son has type 1 diabetes, arthritis, reduced IgG levels and IgA deficiency, but has not inherited the TNFRSF13B/TACI mutation. Her brother, homozygous for the TNFRSF13B/TACI mutation, is in good health despite profound hypogammaglobulinemia and mild cytopenias. We hypothesised that a second unidentified mutation contributed to the symptomatic phenotype of the proband and her son. Whole-exome sequencing of the family revealed a de novo nonsense mutation (T168fsX191) in the Transcription Factor 3 (TCF3) gene encoding the E2A transcription factors, present only in the proband and her son. We demonstrate mutations of TNFRSF13B/TACI impair immunoglobulin isotype switching and antibody production predominantly via T-cell-independent signalling, while mutations of TCF3 impair both T-cell-dependent and -independent pathways of B-cell activation and differentiation. We conclude that epistatic interactions between mutations of the TNFRSF13B/TACI and TCF3 signalling networks lead to the severe CVID-like disorder and SLE in the proband.

The Clinical Significance of Specific Antibody Deficiency (SAD) Severity in Chronic Rhinosinusitis (CRS)

BACKGROUND

Despite the increased identification of specific antibody deficiency (SAD) in chronic rhinosinusitis (CRS), little is known about the relationship between SAD severity and the severity and comorbidities of CRS. The prevalence of an impaired antibody response in the general population is also unknown.

OBJECTIVE

The objective of this study was to determine if the SAD severity stratification applies to real-life data of patients with CRS.

METHODS

An electronic health record database was used to identify patients with CRS evaluated for humoral immunodeficiency with quantitative immunoglobulins and Streptococcus pneumoniae antibody titers before and after pneumococcal vaccine. SAD severity was defined, according to the guidelines, based on the numbers of titers ≥1.3 μg/dL after vaccination: severe (≤2 serotypes), moderate (3-6 serotypes), and mild (7-10 serotypes). Comorbidities and therapeutic response were assessed. The prevalence of an impaired antibody response in a normal population was assessed.

RESULTS

Twenty-four percent of the patients with CRS evaluated for immunodeficiency had SAD, whereas 11% of a normal population had an impaired immune response to polysaccharide vaccination (P < .05). When evaluated by the practice parameter definition, 239 of 595 (40%) met the definition of SAD. Twenty-four (10%) had severe SAD, 120 (50%) had moderate SAD, and 95 (40%) had mild SAD. Patients with moderate-to-severe SAD had worse asthma, a greater likelihood of pneumonia, and more antibiotic courses in the 2 years after vaccination than patients with mild SAD.

CONCLUSIONS

This study provides real world data supporting stratification of SAD by severity, demonstrating a significant increase in the comorbid severity of asthma and infections in CRS patients with moderate-to-severe SAD compared with those with mild SAD and those without SAD.

Immunoglobulin levels and infection risk with rituximab induction for anti-neutrophil cytoplasmic antibody-associated vasculitis

Background

Rituximab (RTX), a B cell–depleting anti-CD20 monoclonal antibody, is approved for treatment of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). Low immunoglobulin (Ig) levels have been observed surrounding RTX treatment. The association between the degree of Ig deficiency and infection risk is unclear in AAV patients.

Methods

AAV patients treated with RTX for remission induction at a single center (2005–15) with serum Ig measurements were included. Patient characteristics; serum IgG, IgM and IgA levels and occurrence of infections were collected retrospectively. Low IgG was defined as mild (376–749 mg/dL) or severe (>375 mg/dL). Logistic regression models were adjusted for age at RTX administration, estimated glomerular filtration rate (eGFR) and race to examine the association of degree and type of Ig deficiency and infection risk.

Results

Our cohort of 30 patients had a mean age of 63 (SD 7) years, 23 were women, 16 had granulomatosis with polyangiitis and 13 were PR3 ANCA positive. Nine patients received concomitant cyclophosphamide. The mean IgG level was 625 mg/dL (SD 289), mean IgM level was 55 mg/dL (SD 41) and mean IgA level was 133 mg/dL (SD 79). In this cohort, 20 patients had low serum IgG levels (<750 mg/dL) following RTX treatment. During the follow-up period, four individuals developed infections requiring hospitalization. In unadjusted logistic regression analysis, an IgG level ≤ 375 mg/dL was associated with 23 times higher odds of hospitalized infection [95% confidence interval (CI) 1.8–298.4; P = 0.02]. After adjustment for age, race and eGFR, results were similar [odds ratio (OR) 21.1 (95% CI 1.1–404.1) P = 0.04]. Low IgA was also associated with an increased risk of infections requiring hospitalization after adjusting for age, race and eGFR [OR 24.6 (95% CI 1.5–799.5) P = 0.03]. Low IgM was not associated with a higher risk of infections requiring hospitalization.

Conclusions

Severe hypogammaglobulinemia was associated with increased odds of infection requiring hospitalization in this cohort. Further investigation is warranted given our study is limited by small sample size, concomitant cyclophosphamide use and variable timing of Ig measurement.

Application of diagnostic and treatment criteria for common variable immunodeficiency disorder

Common variable immunodeficiency disorder (CVID) is the most frequent symptomatic primary immune deficiency disorder in adults. It probably comprises a spectrum of polygenic disorders, with hypogammaglobulinemia being the overarching feature. While the majority of patients with CVID can be identified with relative ease, a significant proportion can present with minimal symptoms in spite of profound laboratory abnormalities. Here we discuss three patients who were presented to the Auckland Hospital immunoglobulin treatment committee to determine if they qualified for immunoglobulin replacement. Two were asymptomatic with profound laboratory abnormalities while the third patient was severely ill with extensive bronchiectasis. The third patient had less severe laboratory abnormalities compared with the two asymptomatic patients. We have applied four sets of published diagnostic and treatment criteria to these patients to compare their clinical utility. We have chosen these patients from the broad phenotypic spectrum of CVID, as this often illustrates differences in diagnostic and treatment criteria.

Rituximab-associated hypogammaglobulinemia: incidence, predictors and outcomes in patients with multi-system autoimmune disease

Rituximab is a B cell depleting monoclonal antibody used to treat lymphoma and autoimmune disease. Hypogammaglobulinemia has occurred after rituximab for lymphoma and rheumatoid arthritis but data are scarce for other autoimmune indications. This study describes the incidence and severity of hypogammaglobulinemia in patients receiving rituximab for small vessel vasculitis and other multi-system autoimmune diseases. Predictors for and clinical outcomes of hypogammaglobulinemia were explored. We conducted a retrospective study in a tertiary referral specialist clinic. The severity of hypogammaglobulinemia was categorized by the nadir serum IgG concentration measured during clinical care. We identified 288 patients who received rituximab; 243 were eligible for inclusion with median follow up of 42 months. 26% were IgG hypogammaglobulinemic at the time that rituximab was initiated and 56% had IgG hypogammaglobulinemia during follow-up (5-6.9 g/L in 30%, 3-4.9 g/L in 22% and <3 g/L in 4%); IgM ≤0.3 g/L in 58%. The nadir IgG was non-sustained in 50% of cases with moderate/severe hypogammaglobulinemia. A weak association was noted between prior cyclophosphamide exposure and nadir IgG concentration, but not cumulative rituximab dose. IgG concentrations prior to and at the time of rituximab correlated with the nadir IgG post rituximab. IgG replacement was initiated because of recurrent infection in 12 (4.2%) patients and a lower IgG increased the odds ratio of receiving IgG replacement. Rituximab is associated with an increased risk of hypogammaglobulinemia but recovery of IgG level can occur. IgG monitoring may be useful for patients receiving rituximab.

Comparison of diagnostic criteria for common variable immunodeficiency disorder

Common variable immunodeficiency disorders (CVIDs) are the most frequent symptomatic primary immune deficiency condition in adults. The genetic basis for the condition is not known and no single clinical feature or laboratory test can establish the diagnosis; it has been a diagnosis of exclusion. In areas of uncertainty, diagnostic criteria can provide valuable clinical information. Here, we compare the revised European society of immune deficiencies (ESID) registry (2014) criteria with the diagnostic criteria of Ameratunga et al. (2013) and the original ESID/pan American group for immune deficiency (ESID/PAGID 1999) criteria. The ESID/PAGID (1999) criteria either require absent isohemagglutinins or impaired vaccine responses to establish the diagnosis in patients with primary hypogammaglobulinemia. Although commonly encountered, infective and autoimmune sequelae of CVID were not part of the original ESID/PAGID (1999) criteria. Also excluded were a series of characteristic laboratory and histological abnormalities, which are useful when making the diagnosis. The diagnostic criteria of Ameratunga et al. (2013) for CVID are based on these markers. The revised ESID registry (2014) criteria for CVID require the presence of symptoms as well as laboratory abnormalities to establish the diagnosis. Once validated, criteria for CVID will improve diagnostic precision and will result in more equitable and judicious use of intravenous or subcutaneous immunoglobulin therapy.

Evaluation of an immunological score to assess the risk of severe infection in heart recipients

BACKGROUND

We previously reported how specific humoral and cellular immunological markers that are readily available in clinical practice can be used to identify heart transplant recipients (HTR) at risk of developing severe infections. In this study, we perform an extended analysis to identify immunological profiles that could prove to be superior to individual markers in assessing the risk of infection early after heart transplantation.

METHODS

In a prospective follow-up study, we evaluated 100 HTR at 1 week after transplantation. Laboratory tests included determination of immunoglobulin (Ig) levels (IgG, IgA, IgM), complement factors (C3 and C4), and lymphocyte subsets (CD3+, CD4+, CD8+ T cells, B cells, and natural killer [NK] cells). The prevalence of infection during the first 3 months was registered at scheduled visits after transplantation. Severe infections were defined as all infections requiring hospitalization and intravenous antimicrobial therapy.

RESULTS

During follow-up, 33 patients (33%) developed severe infections. The individual risk factors of severe infection, according to the Cox regression analysis, were as follows: IgG <600 mg/dL (hazard ratio [HR], 2.41; 95% confidence interval [CI], 1.21-4.78; P = 0.012), C3 <80 mg/dL (HR, 4.65; 95% CI, 2.31-9.38; P < 0.0001), C4 <18 mg/dL (HR 2.30, 95% CI, 1.15-4.59; P = 0.018), NK count <30 cells/μL (HR 4.07, 95% CI, 1.76-9.38; P = 0.001), and CD4 count <350 cells/μL (HR, 3.04; 95% CI, 1.47-6.28; P = 0.0027). An immunological score was created. HRs were used to determine the number of points assigned to each of the 5 previously mentioned individual risk factors. The score was obtained from the sum of these factors. In the multivariate Cox regression analysis, the immunological score was useful for identifying patients at risk of infection and was the only variable that maintained a significant association with the development of infection, after adjustment for the 5 individual factors.

CONCLUSION

Patients with an immunological score ≥13 were at the highest risk of severe infections (HR, 9.29; 95% CI, 4.57-18.90; P < 0.0001). This score remained significantly associated with the risk of severe infection after adjustment for clinical risk factors of infection. An immunological score was useful for identifying HTR at risk of developing severe infections. If this score is validated in multicenter studies, it could be easily introduced into clinical practice.

Advances in basic and clinical immunology in 2013

A significant number of contributions to our understanding of primary immunodeficiencies (PIDs) in pathogenesis, diagnosis, and treatment were published in the Journal in 2013. For example, deficiency of mast cell degranulation caused by signal transducer and activator of transcription 3 deficiency was demonstrated to contribute to the difference in the frequency of severe allergic reactions in patients with autosomal dominant hyper-IgE syndrome compared with that seen in atopic subjects with similar high IgE serum levels. High levels of nonglycosylated IgA were found in patients with Wiskott-Aldrich syndrome, and these abnormal antibodies might contribute to the nephropathy seen in these patients. New described genes causing immunodeficiency included caspase recruitment domain 11 (CARD11), mucosa-associated lymphoid tissue 1 (MALT1) for combined immunodeficiencies, and tetratricopeptide repeat domain 7A (TTC7A) for mutations associated with multiple atresia with combined immunodeficiency. Other observations expand the spectrum of clinical presentation of specific gene defects (eg, adult-onset idiopathic T-cell lymphopenia and early-onset autoimmunity might be due to hypomorphic mutations of the recombination-activating genes). Newborn screening in California established the incidence of severe combined immunodeficiency at 1 in 66,250 live births. The use of hematopoietic stem cell transplantation for PIDs was reviewed, with recommendations to give priority to research oriented to establish the best regimens to improve the safety and efficacy of bone marrow transplantation. These represent only a fraction of significant research done in patients with PIDs that has accelerated the quality of care of these patients. Genetic analysis of patients has demonstrated multiple phenotypic expressions of immune deficiency in patients with nearly identical genotypes, suggesting that additional genetic factors, possibly gene dosage, or environmental factors are responsible for this diversity.

New diagnostic criteria for common variable immune deficiency (CVID), which may assist with decisions to treat with intravenous or subcutaneous immunoglobulin

Common variable immune deficiency (CVID) is the most frequent symptomatic primary immune deficiency in adults. The standard of care is intravenous immunoglobulin (IVIG) or subcutaneous immunoglobulin (scIG) therapy. The cause of CVID is currently unknown, and there is no universally accepted definition of CVID. This creates problems in determining which patients will benefit from IVIG/scIG treatment. In this paper, we review the difficulties with the commonly used European Society of Immune Deficiencies (ESID) and the Pan American Group for Immune Deficiency (PAGID) definition of CVID. We propose new criteria for the diagnosis of CVID, which are based on recent scientific discoveries. Improved diagnostic precision will assist with treatment decisions including IVIG/scIG replacement. We suggest that asymptomatic patients with mild hypogammaglobulinaemia are termed hypogammaglobulinaemia of uncertain significance (HGUS). These patients require long-term follow-up, as some will evolve into CVID.