How I treat common variable immune deficiency

Relation between dysbiosis and inborn errors of immunity

Inborn errors of immunity (IEI) disorders, formerly primary immune deficiency diseases, are a heterogeneous group of disorders with variable hereditary transitions, clinical manifestations, complications and varying disease severity. Many of the clinical symptoms, signs and complications in IEI patients can be attributed to inflammatory and immune dysregulatory processes due to loss of microbial diversity (dysbiosis). For example, in common variable immunodeficiency patients, the diversity of bacteria, but not fungi, in the gut microbiota has been found to be reduced and significantly altered. Again, this was associated with a more severe disease phenotype. Compromise of the STAT3/Th17 pathway in hyper-IgE syndrome may lead to dysbiosis of the oral microbiota in these patients, causing Candida albicans to switch from commensal to pathogenic. Modification of the microbiota can be used as a therapeutic approach in patients with IEI. Prebiotics, probiotics, postbiotics and fecal microbiota transplantation can be used to restore the balance of the gut microbiota and reduce pathogenicity in IEI patients. Clinical trials are currently underway to understand the impact of this dysbiosis on the phenotype of IEI diseases and its role in their treatment.

Immunological biomarkers associated with survival in a cohort of Argentinian patients with common variable immunodeficiency

Background

Common variable immunodeficiency (CVID) is the most common symptomatic syndrome among inborn errors of immunity. Although several aspects of CVID immunopathology have been elucidated, predictive factors for mortality are incompletely defined. A genetic cause can be identified only in approximately 30% of patients.

Objective

We sought to develop a mortality predictive score on the basis of the immunophenotypes and genotypes of patients with CVID.

Methods

Twenty-one patients diagnosed with CVID in Córdoba, Argentina, were analyzed for clinical and laboratory data. Immunophenotyping was done by flow cytometry. CVID-associated mutations were identified by whole-exome sequencing.

Results

Alive (15) and deceased (6) patients were compared. Univariate analysis showed significant differences in CD4+ T cells (P = .002), natural killer (NK) cells (P = .001), and memory switched B cells (P = .001) between groups. Logistic regression analysis showed a negative correlation between CD4+, NK, and memory switched B-cell counts and probability of survival over a 10-year period (CD4+ T cells: odds ratio [OR], 1.01; 95% CI, 1.001-1.020; NK cells: OR, 1.07; 95% CI, 1.02-1.17; and memory switched B cells: OR, 26.23; 95% CI, 2.06-2651.96). Receiver-operating characteristic curve analysis identified a survival cutoff point for each parameter (CD4+ T cells: 546 cells/mL; AUC, 0.87; sensitivity, 60%; specificity, 100%; memory switched B cells: 0.84 cells/mL; AUC, 0.92; sensitivity, 100%; specificity, 85%; and NK cells: 45 cells/mL; AUC, 0.92; sensitivity, 83%; specificity, 100%). Genetic analysis on 14 (9 female and 5 male) patients from the cohort revealed mutations associated with inborn errors of immunity in 6 patients.

Conclusions

A score to predict mortality is proposed on the basis of CD4+ T, NK, and memory switched B-cell counts in patients with CVID.

CVID With Unusual Peripheral Mononeuropathy and Associated IL-7 Receptor Mutation

Common variable immunodeficiency (CVID) is the most common symptomatic primary immunodeficiency. It is characterized by hypogammaglobulinemia and can present with a broad range of symptoms including recurrent bacterial infections, autoimmunity, and malignancy. Rarely, it has been implicated with peripheral neuropathy. We present a case of CVID with peripheral neuropathy and a pathogenic heterozygous variant of IL-7 receptor gene. The patient is a 38-year-old female with a history of recurrent infections since childhood including pneumonia and sinus infections status post tonsillectomy and sinus surgery. She subsequently developed severe left leg and lower back pain that progressed to left foot drop and decreased sensation over the left leg. She was found to have severe hypogammaglobulinemia and poor polysaccharide and protein response, thus meeting criteria for CVID. Mononeuropathy is a rare finding in CVID. Genetic panel was performed and was significant for a single pathogenic variant in IL-7 receptor. Disruptions in the IL-7 and IL-7 receptor signaling pathway have been associated with autoimmunity such as rheumatoid arthritis and multiple sclerosis. Further investigation is indicated to determine the clinical significance of this variant.

Altered Genome-Wide DNA Methylation in the Duodenum of Common Variable Immunodeficiency Patients

PURPOSE

A large proportion of Common variable immunodeficiency (CVID) patients has duodenal inflammation with increased intraepithelial lymphocytes (IEL) of unknown aetiology. The histologic similarities to celiac disease, lead to confusion regarding treatment (gluten-free diet) of these patients. We aimed to elucidate the role of epigenetic DNA methylation in the aetiology of duodenal inflammation in CVID and differentiate it from true celiac disease.

METHODS

DNA was isolated from snap-frozen pieces of duodenal biopsies and analysed for differences in genome-wide epigenetic DNA methylation between CVID patients with increased IEL (CVID_IEL; n = 5) without IEL (CVID_N; n = 3), celiac disease (n = 3) and healthy controls (n = 3).

RESULTS

The DNA methylation data of 5-methylcytosine in CpG sites separated CVID and celiac diseases from healthy controls. Differential methylation in promoters of genes were identified as potential novel mediators in CVID and celiac disease. There was limited overlap of methylation associated genes between CVID_IEL and Celiac disease. High frequency of differentially methylated CpG sites was detected in over 100 genes nearby transcription start site (TSS) in both CVID_IEL and celiac disease, compared to healthy controls. Differential methylation of genes involved in regulation of TNF/cytokine production were enriched in CVID_IEL, compared to healthy controls.

CONCLUSION

This is the first study to reveal a role of epigenetic DNA methylation in the etiology of duodenal inflammation of CVID patients, distinguishing CVID_IEL from celiac disease. We identified potential biomarkers and therapeutic targets within gene promotors and in high-frequency differentially methylated CpG regions proximal to TSS in both CVID_IEL and celiac disease.

CVID-Associated Intestinal Disorders in the USIDNET Registry: An Analysis of Disease Manifestations, Functional Status, Comorbidities, and Treatment

Common variable immunodeficiency (CVID) has been subdivided into five phenotypes, including one marked by non-infectious enteropathies that lead to significant morbidity and mortality. We examined a large national registry of patients with CVID to better characterize this population and understand how the presence of enteropathy influences nutritional status, patient function, and the risk of additional non-infectious disorders in CVID patients. We also sought to illustrate the range of treatment strategies for CVID-associated enteropathies. We extracted patient data from the United States Immunodeficiency Network (USIDNET) database, which included 1415 patients with CVID, and compared those with and without intestinal disorders. Demographic and genetic profiles, functional status, and treatments targeting intestinal disorders are reported. Intestinal disorders were present in 20% of patients with CVID, including chronic diarrhea, inflammatory bowel disease, malabsorption, and others. Compared to those without enteropathies, this patient subset exhibited significantly lower Karnofsky-Lansky functional scores, greater reliance on nutritional support, higher rates of vitamin deficiencies, and increased prevalence of hematologic disorders, liver disease, pulmonary disease, granulomatous disease, and lymphoma. Genetic data were reported for only 5% of the cohort. No mutations segregated significantly to patients with or without intestinal disease. Corticosteroids were most frequently used for treatment. Patients with CVID-associated intestinal disorders exhibit higher rates of autoimmune and inflammatory comorbidities, lymphoma, malnutrition, and debility. We review recent studies implicating specific pathways underlying this immune dysregulation. Further studies are needed to evaluate the role of targeted immunomodulatory therapies for CVID-associated intestinal disorders.

The Importance of Considering Common Variable Immunodeficiency in Patients With Chronic Diarrhea

Chronic diarrhea poses a diagnostic challenge due to its diverse etiology, encompassing various gastrointestinal disorders. This case report emphasizes the clinical significance of considering common variable immunodeficiency (CVID) as a potential underlying cause in a patient presenting with chronic diarrhea. In this case study, we describe a 36-year-old female with a 9-year history of chronic diarrhea, recurrent sinopulmonary infections, and weight loss for 3 years, where previous evaluations failed to yield a diagnosis. This case underscores the diagnostic hurdles faced by healthcare professionals, often causing a delay in identifying fewer common conditions like immunodeficiency syndromes. Early recognition of CVID is crucial, enabling timely intervention with immunoglobulin replacement therapy, markedly enhancing patients' quality of life and averting complications. This report highlights the necessity for a comprehensive evaluation of non-responsive chronic diarrhea cases and raises awareness about CVID as an essential consideration, facilitating precise diagnoses and tailored treatments.

Antibody Response to SARS-CoV-2 Vaccination in Heart Failure Patients: Retrospective Single-Center Cohort Study

We sought to investigate the impact of heart failure on anti-spike antibody positivity following SARS-CoV-2 vaccination. Our study included 103 heart failure (HF) patients, including those with and without left ventricular assist devices (LVAD) selected from our institutional transplant waiting list as well as 104 non-heart failure (NHF) patients who underwent open heart surgery at our institution from 2021 to 2022. All the patients received either heterologous or homologous doses of BNT162b2 and CoronaVac. The median age of the HF group was 56.0 (interquartile range (IQR): 48.0-62.5) and the NHF group was 63.0 (IQR: 56.0-70.2) years, and the majority were males in both groups (n = 78; 75.7% and n = 80; 76.9%, respectively). The majority of the patients in both the HF and NHF groups received heterologous vaccinations (n = 43; 41.7% and n = 52; 50.3%, respectively; p = 0.002). There was no difference in the anti-spike antibody positivity between the patients with and without heart failure (p = 0.725). Vaccination with BNT162b2 led to significantly higher antibody levels compared to CoronaVac alone (OR: 11.0; 95% CI: 3.8-31.5). With each passing day after the last vaccine dose, there was a significant decrease in anti-spike antibody positivity, with an OR of 0.9 (95% CI: 0.9-0.9). Furthermore, hyperlipidemia was associated with increased antibody positivity (p = 0.004).

Understanding the Spectrum of Immune Dysregulation Manifestations in Autoimmune Lymphoproliferative Syndrome and Autoimmune Lymphoproliferative Syndrome-like Disorders

As a disorder of immune dysregulation, autoimmune lymphoproliferative syndrome (ALPS) stems from pathogenic variants in the first apoptosis signal-mediated apoptosis (Fas) and Fas-ligand pathway that result in elevations of CD3+ TCRαβ+ CD4- CD8- T cells along with chronic lymphoproliferation, a heightened risk for malignancy, and importantly for the rheumatologist, increased risk of autoimmunity. While immune cytopenias are the most encountered autoimmune phenomena, there is increasing appreciation for ocular, musculoskeletal, pulmonary and renal inflammatory manifestations similar to more common rheumatology diseases. Additionally, ALPS-like conditions that share similar clinical features and opportunities for targeted therapy are increasingly recognized via genetic testing, highlighting the need for rheumatologists to be facile in the recognition and diagnosis of this spectrum of disorders. This review will focus on clinical and laboratory features of both ALPS and ALPS-like disorders with the intent to provide a framework for rheumatologists to understand the pathophysiologic drivers and discriminate between diagnoses.

Could Immune Checkpoint Disorders and EBV Reactivation Be Connected in the Development of Hematological Malignancies in Immunodeficient Patients?

Primary immunodeficiencies (PIDs) and secondary immunodeficiencies (SIDs) are characterized by compromised immune function, rendering individuals susceptible to infections and potentially influencing cancer development. Epstein-Barr virus (EBV), a widespread herpesvirus, has been linked to cancer, particularly in those with weakened immune systems. This study aims to compare selected immune parameters, focusing on immune checkpoint molecules (PD-1/PD-L1, CTLA-4/CD86, CD200R/CD200), and EBV reactivation in patients with chronic lymphocytic leukemia (CLL, a representative of SIDs) and common variable immunodeficiency (CVID, a representative of PIDs). We performed a correlation analysis involving patients diagnosed with CLL, CVID, and a healthy control group. EBV reactivation was assessed using specific antibody serology and viral load quantification. Peripheral blood morphology, biochemistry, and immunophenotyping were performed, with emphasis on T and B lymphocytes expressing immune checkpoints and their serum concentrations. Our findings revealed elevated EBV reactivation markers in both CLL and CVID patients compared with healthy controls, indicating increased viral activity in immunodeficient individuals. Furthermore, immune checkpoint expression analysis demonstrated significantly altered percentages of T and B lymphocytes expressing PD-1/PD-L1, CTLA-4/CD86, and CD200R/CD200 in CLL and CVID patients. This suggests a potential interplay between immune checkpoint dysregulation and EBV reactivation in the context of immunodeficiency. In conclusion, our study underscores the intricate relationship between immune dysfunction, EBV reactivation, and immune checkpoint modulation in the context of immunodeficiency-associated cancers. The altered expression of immune checkpoints, along with heightened EBV reactivation, suggests a potential mechanism for immune evasion and tumor progression. These findings provide insights into the complex interactions that contribute to cancer development in immunocompromised individuals, shedding light on potential therapeutic targets for improved management and treatment outcomes. Further investigations are warranted to elucidate the underlying mechanisms and to explore potential interventions to mitigate cancer risk in these patient populations.

In Vivo Antiviral Efficacy of LCTG-002, a Pooled, Purified Human Milk Secretory IgA product, Against SARS-CoV-2 in a Murine Model of COVID-19

Immunoglobulin A (IgA) is the most abundant antibody (Ab) in human mucosal compartments including the respiratory tract, with the secretory form of IgA (sIgA) being dominant and uniquely stable in these environments. sIgA is naturally found in human milk, which could be considered a global resource for this biologic, justifying the development of human milk sIgA as a dedicated airway therapeutic for respiratory infections such as SARS-CoV-2. In the present study, methods were therefore developed to efficiently extract human milk sIgA from donors who were either immunologically naïve to SARS-CoV-2 (pooled as a control IgA) or had recovered from a PCR-confirmed SARS-CoV-2 infection that elicited high-titer anti-SARS-CoV-2 Spike sIgA Abs in their milk (pooled together to make LCTG-002). Mass spectrometry determined that proteins with a relative abundance of 1.0% or greater were all associated with sIgA. None of the proteins exhibited statistically significant differences between batches. Western blot demonstrated all batches consisted predominantly of sIgA. Compared to control IgA, LCTG-002 demonstrated significantly higher binding to Spike, and was also capable of blocking the Spike - ACE2 interaction in vitro with 6.3x greater potency compared to control IgA (58% inhibition at ∼240ug/mL). LCTG-002 was then tested in vivo for its capacity to reduce viral burden in the lungs of K18+hACE2 transgenic mice inoculated with SARS-CoV-2. LCTG-002 was demonstrated to significantly reduce SARS-CoV-2 titers in the lungs compared to control IgA when administered at either 250ug/day or 1 mg/day, as measured by TCID50, plaque forming units (PFU), and qRT-PCR, with a maximum reduction of 4.9 logs. This innovative study demonstrates that LCTG-002 is highly pure, efficacious, and well tolerated in vivo, supporting further development of milk-derived, polyclonal sIgA therapeutics against SARS-CoV-2 and other mucosal infections.

Disturbed lipid profile in common variable immunodeficiency - a pathogenic loop of inflammation and metabolic disturbances

The relationship between metabolic and inflammatory pathways play a pathogenic role in various cardiometabolic disorders and is potentially also involved in the pathogenesis of other disorders such as cancer, autoimmunity and infectious diseases. Common variable immunodeficiency (CVID) is the most common primary immunodeficiency in adults, characterized by increased frequency of airway infections with capsulated bacteria. In addition, a large proportion of CVID patients have autoimmune and inflammatory complications associated with systemic inflammation. We summarize the evidence that support a role of a bidirectional pathogenic interaction between inflammation and metabolic disturbances in CVID. This include low levels and function of high-density lipoprotein (HDL), high levels of triglycerides (TG) and its major lipoprotein very low-density lipoprotein (VLDL), and an unfavorable fatty acid (FA) profile. The dysregulation of TG, VLDL and FA were linked to disturbed gut microbiota profile, and TG and VLDL levels were strongly associated with lipopolysaccharides (LPS), a marker of gut leakage in blood. Of note, the disturbed lipid profile in CVID did not include total cholesterol levels or high low-density lipoprotein levels. Furthermore, increased VLDL and TG levels in blood were not associated with diet, high body mass index and liver steatosis, suggesting a different phenotype than in patients with traditional cardiovascular risk such as metabolic syndrome. We hypothesize that these metabolic disturbances are linked to inflammation in a bidirectional manner with disturbed gut microbiota as a potential contributing factor.

CVID-associated intestinal disorders in the USIDNET registry: An analysis of disease manifestations, functional status, comorbidities, and treatment

Common variable immunodeficiency (CVID) has been subdivided into five phenotypes, including one marked by non-infectious enteropathies that lead to significant morbidity and mortality. We examined a large national registry of patients with CVID to better characterize this population and understand how the presence of enteropathy influences nutritional status, patient function, and the risk of additional non-infectious disorders in CVID patients. We also sought to illustrate the range of treatment strategies for CVID-associated enteropathies. We extracted patient data from the United States Immunodeficiency Network (USIDNET) database, which included 1415 patients with CVID, and compared those with and without intestinal disorders. Demographic and genetic profiles, functional status, and treatments targeting intestinal disorders are reported. Intestinal disorders were present in 20% of patients with CVID, including chronic diarrhea, inflammatory bowel disease, malabsorption, and others. Compared to those without enteropathies, this patient subset exhibited significantly lower Karnofsky-Lansky functional scores, greater reliance on nutritional support, higher rates of vitamin deficiencies, and increased prevalence of hematologic disorders, liver disease, pulmonary disease, granulomatous disease, and lymphoma. Genetic data were reported for only 5% of the cohort. No mutations segregated significantly to patients with or without intestinal disease. Corticosteroids were most frequently used for treatment. Patients with CVID-associated intestinal disorders exhibit higher rates of autoimmune and inflammatory comorbidities, lymphoma, malnutrition, and debility. We review recent studies implicating specific pathways underlying this immune dysregulation. Further studies are needed to evaluate the role of targeted immunomodulatory therapies for CVID-associated intestinal disorders.

Increased Plasma Levels of Triglyceride-Enriched Lipoproteins Associate with Systemic Inflammation, Lipopolysaccharides, and Gut Dysbiosis in Common Variable Immunodeficiency

PURPOSE

Triglycerides (TG) and their major transport lipoprotein in the circulation (VLDL) appear to be related to inflammation. Patients with common variable immunodeficiency (CVID) have inflammatory complications associated with gut microbial dysbiosis. We hypothesized that CVID patients have disturbed TG/VLDL profiles associated with these clinical characteristics.

METHODS

We measured plasma concentrations of TGs, inflammatory markers, and lipopolysaccharide (LPS) in 95 CVID patients and 28 healthy controls. Additionally, in 40 CVID patients, we explored plasma lipoprotein profiling, fatty acid, gut microbial dysbiosis, and diet.

RESULTS

TG levels were increased in CVID patients as compared to healthy controls (1.36 ± 0.53 mmol/l versus 1.08 ± 0.56 [mean, SD], respectively, P = 0.008), particularly in the clinical subgroup "Complications," characterized by autoimmunity and organ-specific inflammation, compared to "Infection only" (1.41 mmol/l, 0.71[median, IQR] versus [1.02 mmol/l, 0.50], P = 0.021). Lipoprotein profile analyses showed increased levels of all sizes of VLDL particles in CVID patients compared to controls. TG levels correlated positively with CRP (rho = 0.256, P = 0.015), IL-6 (rho = 0.237, P = 0.021), IL-12 (rho = 0.265, P = 0.009), LPS (r = 0.654, P = 6.59 × 10^-13), CVID-specific gut dysbiosis index (r = 0.315, P = 0.048), and inversely with a favorable fatty acid profile (docosahexaenoic acid [rho =  - 0.369, P = 0.021] and linoleic acid [rho =  - 0.375, P = 0.019]). TGs and VLDL lipids did not appear to be associated with diet and there were no differences in body mass index (BMI) between CVID patients and controls.

CONCLUSION

We found increased plasma levels of TGs and all sizes of VLDL particles, which were associated with systemic inflammation, LPS, and gut dysbiosis in CVID, but not diet or BMI.

Treatment of inflammatory complications in common variable immunodeficiency (CVID): current concepts and future perspectives

INTRODUCTION

Patients with Common variable immunodeficiency (CVID) have a high frequency of inflammatory complications like autoimmune cytopenias, interstitial lung disease and enteropathy. These patients have poor prognosis and effective, timely and safe treatment of inflammatory complications in CVID are essential, but guidelines and consensus on therapy are often lacking.

AREAS COVERED

This review will focus on current medical treatment of inflammatory complications in CVID and point out some future perspectives based on literature indexed in PubMed. There are a number of good observational studies and case reports on treatment of specific complications but randomized controlled trials are scarce.

EXPERT OPINION

In clinical practice, the most urgent issues that need to be addressed are the preferred treatment of GLILD, enteropathy and liver disease. Treating the underlying immune dysregulation and immune exhaustion in CVID is an alternative approach that potentially could alleviate these and other organ-specific inflammatory complications. Therapies of potential interest and wider use in CVID include mTOR-inhibitors like sirolimus, JAK-inhibitors like tofacitinib, the monoclonal IL-12/23 antibody ustekinumab, the anti-BAFF antibody belimumab and abatacept. For all inflammatory complications, there is a need for prospective therapeutic trials, preferably randomized controlled trials, and multi-center collaborations with larger cohorts of patients will be essential.

Successful Treatment of Granulomatous-lymphocytic Interstitial Lung Disease in a Patient with CTLA-4 Deficiency

Common variable immunodeficiency (CVID) causes granulomatous-lymphocytic interstitial lung disease (GLILD) and has a poor prognosis. We herein report a case of GLILD in a 49-year-old woman with CTLA-4 deficiency-associated CVID. The patient presented with dyspnea that had worsened over the past two years. A laboratory examination revealed hypoglobulinemia and pancytopenia. Chest computed tomography showed diffuse infiltrative and granular shadows in the bilateral interstitium. A flow cytometric analysis of blood cells and genetic testing confirmed CTLA-4 deficiency. We performed video-assisted thoracoscopic surgery for the pathological diagnosis of GLILD and to exclude infection and malignancy. Corticosteroid treatment successfully improved the condition of the patient.

Duodenal inflammation in common variable immunodeficiency has altered transcriptional response to viruses

BACKGROUND

A substantial proportion of common variable immunodeficiency (CVID) patients has duodenal inflammation of largely unknown etiology. However, because of its histologic similarities with celiac disease, gluten sensitivity has been proposed as a potential mechanism.

OBJECTIVE

We aimed to elucidate the role of the duodenal microenvironment in the pathogenesis of duodenal inflammation in CVID by investigating the transcriptional, proteomic, and microbial signatures of duodenal biopsy samples in CVID.

METHODS

DNA, total RNA, and protein were isolated from snap-frozen pieces of duodenal biopsy samples from CVID (with and without duodenal inflammation), healthy controls, and patients with celiac disease (untreated). RNA sequencing, mass spectrometry-based proteomics, and 16S ribosomal DNA sequencing (bacteria) were then performed.

RESULTS

CVID separated from controls in regulation of transcriptional response to lipopolysaccharide and cellular immune responses. These differences were independent of mucosal inflammation. Instead, CVID patients with duodenal inflammation displayed alterations in transcription of genes involved in response to viral infections. Four proteins were differently regulated between CVID patients and healthy controls-DBNL, TRMT11, GCHFR, and IGHA2-independent of duodenal inflammation. Despite similar histology, there were major differences in CVID with duodenal inflammation and celiac disease both at the RNA and protein level. No significant difference was observed in the bacterial gut microbial signature between CVID, celiac, and healthy controls.

CONCLUSION

Our findings suggest the existence of altered functions of the duodenal epithelium, particularly in response to lipopolysaccharide and viruses. The latter finding was related to duodenal inflammation, suggesting that viruses, not gluten sensitivity, could be related to duodenal inflammation in CVID.

Primary Antibody Immunodeficiency and the Pregnant Patient

An overview of primary antibody immunodeficiency in pregnancy is presented. Indications for immunoglobulin replacement therapy (IGRT), dosing, and safety considerations are highlighted. Uses of immunizations and antimicrobial therapy are also discussed. In general, IGRT, both intravenous and subcutaneous, is considered safe in pregnancy.

Clinical Outcome of Coronavirus Disease 2019 in Patients with Primary Antibody Deficiencies

In 2019, the novel coronavirus, SARS-CoV-2, caused a worldwide pandemic, affecting more than 630 million individuals and causing 6.5 million deaths. In the general population, poorer outcomes have been associated with older age, chronic lung and cardiovascular diseases, and lymphopenia, highlighting the important role of cellular immunity in the immune response against SARS-CoV-2. Moreover, SARS-CoV-2 variants may have a significant impact on disease severity. There is a significant overlap with complications commonly found in inborn errors of immunity (IEI), such as primary antibody deficiencies. The results of various studies have provided ambiguous findings. Several studies identified risk factors in the general population with a minor impact on SARS-CoV-2 infection. However, other studies have found a significant contribution of underlying immunodeficiency and immune-system dysregulation to the disease course. This ambiguity probably reflects the demographic differences and viral evolution. Impaired antibody production was associated with prolonged viral shedding, suggesting a critical role of humoral immunity in controlling SARS-CoV-2 infection. This may explain the poorer outcomes in primary antibody deficiencies compared to other IEIs. Understanding coronavirus disease 2019 (COVID-19) pathogenesis and identifying risk factors may help us identify patients at high risk of severe COVID-19 for whom preventive measures should be introduced.

Cellular immunity in COVID-19 and other infections in Common variable immunodeficiency

COVID-19 has shed light on the role of cellular immunity in the absence of humoral response in different patient groups. Common variable immunodeficiency (CVID) is characterized by impaired humoral immunity but also an underlying T-cell dysregulation. The impact of T-cell dysregulation on cellular immunity in CVID is not clear, and this review summarizes available literature on cellular immunity in CVID with a particular focus on COVID-19. Overall mortality of COVID-19 in CVID is difficult to assess, but seems not significantly elevated, and risk factors for severe disease mirrors that of the general population, including lymphopenia. Most CVID patients have a significant T-cell response to COVID-19 disease with possible cross-reactivity to endemic coronaviruses. Several studies find a significant but impaired cellular response to basal COVID-19 mRNA vaccination that is independent of an antibody response. CVID patients with infection only have better cellular responses to vaccine in one study, but there is no clear association to T-cell dysregulation. Cellular response wane over time but responds to a third booster dose of vaccine. Opportunistic infection as a sign of impaired cellular immunity in CVID is rare but is related to the definition of the disease. CVID patients have a cellular response to influenza vaccine that in most studies is comparable to healthy controls, and annual vaccination against seasonal influenza should be recommended. More research is required to clarify the effect of vaccines in CVID with the most immediate issue being when to booster the COVID-19 vaccine.

Hepatitis E infection in adults with primary immunodeficiency with or without immunoglobulin replacement therapy

BACKGROUND

In a context of secondary immunodeficiency, hepatitis E virus (HEV) infection can be responsible for chronic liver disease.

MATERIALS AND METHODS

We investigated HEV infection in patients with primary immunodeficiency treated (or not) with immunoglobulin (Ig) replacement therapy (IgRT) in France, a country with a high seroprevalence of HEV. In a nationwide study of individuals with primary immunodeficiency, 533 patients (349 and 184 receiving IgRT or not, respectively) were tested for HEV RNA and anti-HEV antibodies. In addition, 23 batches of five different commercially available immunoglobulin preparations were screened for anti-HEV IgG.

RESULTS

Three of the 533 patients displayed markers of a recent HEV infection (HEV RNA in one case, and anti-HEV IgG and IgM in two) but no evidence of chronic liver disease. The overall seroprevalence of HEV was 50% (266 out of 533), with values of 68% and 16% in patients receiving IgRT or not, respectively (p<0.001). Anti-HEV IgG were detected in all batches of immunoglobulin preparations, although the titer varied from 3 to 127 IU/g IgG. Seroconversion was observed in 15 of the 22 (68%) patients tested before and after IgRT.

DISCUSSION

No cases of chronic HEV-related disease were detected among patients with primary immunodeficiency and hypogammaglobulinemia, whether they received IgRT or not. This confirms that patients with primary immunodeficiency have a low risk of chronic infection despite a seroprevalence close to that observed in the French general population and that IgRT, which confers a high HEV seroprevalence, might play a key role in protection against chronic infection.

Myelodysplastic Syndrome in a Patient With Common Variable Immunodeficiency: A Rare Occurrence

Common variable immunodeficiency (CVID) is a primary immunodeficiency disorder caused by impaired B-cell function and antibody production. It commonly presents with chronic sinopulmonary and gastrointestinal manifestations. It is also associated with transformation to acute myeloid leukemia. However, the association of CVID with myelodysplastic syndrome (MDS) is rare. This case report aims to present one such rare association in a 26-year-old patient presenting with severe thrombocytopenia. Bone marrow biopsy revealed hypercellular marrow with 80-90% cellularity along with an increase in CD34 blasts. Cytogenetics revealed loss of the Y chromosome. Diagnosis of MDS with excess blasts-2 was confirmed with a Revised International Prognostic Scoring System score of 4, placing the patient in the intermediate-risk category. The patient was started on azacitidine, a hypomethylating agent. A referral to a bone marrow transplant was also done for the consideration of an allogeneic stem cell transplant.

Raised Serum Markers of T Cell Activation and Exhaustion in Granulomatous-Lymphocytic Interstitial Lung Disease in Common Variable Immunodeficiency

Purpose

About 20–30% of patients with common variable immunodeficiency (CVID) develop granulomatous-lymphocytic interstitial lung disease (GLILD) as one of several non-infectious complications to their immunodeficiency. The purpose of this study was to identify biomarkers that could distinguish GLILD from other non-infectious complications in CVID.

Methods

We analyzed serum biomarkers related to inflammation, pulmonary epithelium injury, fibrogenesis, and extracellular matrix (ECM) remodeling, and compared three subgroups of CVID: GLILD patients (n = 16), patients with other non-infectious complications (n = 37), and patients with infections only (n = 20).

Results

We found that GLILD patients had higher levels of sCD25, sTIM-3, IFN-γ, and TNF, reflecting T cell activation and exhaustion, compared to both CVID patients with other inflammatory complications and CVID with infections only. GLILD patients also had higher levels of SP-D and CC16, proteins related to pulmonary epithelium injury, as well as the ECM remodeling marker MMP-7, than patients with other non-infectious complications.

Conclusion

GLILD patients have elevated serum markers of T cell activation and exhaustion, pulmonary epithelium injury, and ECM remodeling, pointing to potentially important pathways in GLILD pathogenesis, novel targets for therapy, and promising biomarkers for clinical evaluation of these patients.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10875-022-01318-1.

Lymphoproliferation in Inborn Errors of Immunity: The Eye Does Not See What the Mind Does Not Know

Inborn errors of immunity (IEIs) are a group of heterogeneous disorders characterized by a broad clinical spectrum of recurrent infections and immune dysregulation including autoimmunity and lymphoproliferation (LP). LP in the context of IEI may be the presenting feature of underlying immune disorder or may develop during the disease course. However, the correct diagnosis of LP in IEI as benign or malignant often poses a diagnostic dilemma due to the non-specific clinical features and overlapping morphological and immunophenotypic features which make it difficult to treat. There are morphological clues to LP associated with certain IEIs. A combination of ancillary techniques including EBV-associated markers, flow cytometry, and molecular assays may prove useful in establishing a correct diagnosis in an appropriate clinical setting. The present review attempts to provide comprehensive insight into benign and malignant LP, especially the pathogenesis, histological clues, diagnostic strategies, and treatment options in patients with IEIs.

Clinical and Phenotypic Characterization of Common Variable Immunodeficiency Diagnosed in Younger and Older Adults

PURPOSE

Common variable immunodeficiency (CVID) is the most prevalent symptomatic immunodeficiency in adults. Little is known about the manifestations of CVID presenting in older adults. Herein, we performed a phenotypic characterization of patients diagnosed older than age 40.

METHODS

A retrospective chart review of 79 patients seen at UF Health between 2006 and 2020 with a verified diagnosis of CVID per the ICON 2016 criteria was conducted. Patients were classified according to four phenotypes: no-disease-related complications, autoimmune cytopenias, polyclonal lymphoproliferation, and unexplained enteropathy. Patients diagnosed with CVID from age 2 to 40 (n = 41, "younger cohort") were compared to patients diagnosed with CVID age 41 and older (n = 38, "older cohort").

RESULTS

Among the younger cohort, pathologic genetic variants, positive family history for immunodeficiency, autoimmunity (49% vs 24%, p = 0.03), and splenomegaly (46% vs 16%, p = 0.004) were more common, as was the "autoimmune cytopenias" phenotype (24% vs 3%, p = 0.007). Among the older cohort, lymphoma (11% vs 0%, p = 0.049) and the "no disease-related complications" phenotype (79% vs 57%, p = 0.03) were more commonly seen. Comorbidities such as bronchiectasis (27% vs 21%, p = 0.61), GI involvement (34% vs 24%, p = 0.33), and GLILD (5% vs 8%, p = 0.67) were equally present among both the younger and older cohorts, respectively.

CONCLUSION

The lower incidence of autoimmunity and splenomegaly, as well as overlapping clinical features with immunosenescence, may make diagnosing CVID in older patients more challenging; however, the disease is not more indolent as the risks for lymphoma, bronchiectasis, and GLILD are similar to those of younger patients.

Evaluation of Humoral and Cellular Immune Responses to the SARS-CoV-2 Vaccine in Patients With Common Variable Immunodeficiency Phenotype and Patient Receiving B-Cell Depletion Therapy

Introduction

SARS-CoV-2 vaccines' effectiveness is not yet clearly known in immunocompromised patients. This study aims to assess the humoral and cellular specific immune response to SARS-CoV-2 vaccines and the predictors of poor response in patients with common variable immunodeficiency (CVID) phenotype and in patients treated with B-cell depletion therapies (BCDT), as well as the safety of these vaccines.

Methods

From March to September 2021, we performed a prospective study of all adult patients who would receive the SARS-CoV-2 vaccination and were previously diagnosed with (i) a CVID syndrome (CVID phenotype group; n=28) or (ii) multiple sclerosis (MS) treated with B-cell depleting therapies three to six months before vaccination (BCD group; n=24). Participants with prior SARS-CoV-2 infection; or prior SARS-CoV-2 vaccine administration; or use of any immunosuppressant (except BCDT in MS group) were excluded. A group of subjects without any medical condition that confers immunosuppression and who met all study criteria was also assessed (control group; n=14). A chemiluminescence immunoassay was used to determine pre- and post-SARS-CoV-2 vaccine anti-S IgG antibodies. T-cell specific response was assessed by analysis of pre- and post-SARS-CoV-2 vaccination blood samples with an interferon-gamma release assay. The baseline blood sample also included several biochemical, haematological and immunological analyses.

Results

SARS-CoV-2 vaccines are safe in immunocompromised patients, although their effectiveness was lower than in healthy individuals. CVID phenotype patients showed impaired humoral (29%) and cellular (29%) response, while BCD patients fundamentally presented humoral failure (54%). Low IgA values, low CD19+ peripheral B cells, low switched memory B cells, and a low CD4+/CD8+ ratio were predictors of inadequate specific antibody response in CVID phenotype patients. No factor was found to predict poor cellular response in CVID phenotype patients, nor a defective humoral or cellular response in BCD patients.

Conclusion

The effectiveness of SARS-CoV-2 vaccines in CVID phenotype and BCD patients is lower than in healthy individuals. Knowledge of predictive factors of humoral and cellular response failure in immunocompromised patients could be very useful in clinical practice, and thus, studies in this regard are clearly needed.

Monitoring patients with uncomplicated common variable immunodeficiency: a systematic review

BACKGROUND

Non-infectious complications have become a major cause of morbidity and mortality in patients with Common Variable Immunodeficiency (CVID). The monitoring of patients with CVID prior to the development of non-infectious complications is not well defined.

OBJECTIVE

Our objectives were to systematically review the current literature on the monitoring of CVID patients without non-infectious complications and to develop recommendations for such monitoring.

METHODS

MEDLINE and EMBASE were searched from January 1^st, 2000 to March 25^th, 2021. Studies on any aspects of CVID monitoring were included. Studies that included only children, on monitoring CVID patients with existing non-infectious complications, or in the format of case reports were excluded.

RESULTS

Nine studies on CVID monitoring, including 3 cohort studies, 3 experts' opinions, 2 consensus statements and a single guideline report were identified. These studies revealed that clinical assessment and bloodwork were preformed every 6 to 12 months in asymptomatic patients. Some centers performed computerized tomography scan of the chest every 2-5 years to identify chronic lung disease, although the majority did chest imaging in accordance with clinical indications. Pulmonary function tests were done annually at most centers. Most studies did not address the role of abdominal imaging to screen for liver diseases or endoscopy to screen for gastric cancer in asymptomatic patients with uncomplicated CVID.

CONCLUSIONS

There is paucity of evidence-based information to guide the routine monitoring of CVID patients without non-infectious complications. Prospective studies are needed to determine the best monitoring practices in this group of patients.

COMMON VARIABLE IMMUNODEFICIENCY: PREDISPOSING OR PROTECTIVE FACTOR FOR SEVERE COMPLICATIONS OF COVID-19?

Coronavirus disease 2019 (COVID-19) is an emerging infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The usual presentation of the disease is a common cold-like illness but it can present with more severe and sometimes fatal manifestations. Immunocompromised patients such as those with common variable immunodeficiency (CVID) also are among the infected population. A limited number of reports have been published concerning CVID patients with COVID-19. The main reported symptoms were fever, cough, dyspnea and fatigue while the median duration of illness was 19 (interquartile range 14-26.5) days. Total recovery rate was 88.4%. It is still unknown whether primary immunodeficiency interacts as a predisposing or protective factor against the severe forms of COVID-19. Substitute immunoglobulin (IG) therapy is the only treatment option for CVID. Some reports suggest that early administration of intravenous IGs or convalescent plasma infusion may positively influence the outcome of COVID-19 in these patients.

Gut inflammation in CVID: causes and consequences

INTRODUCTION

There is a wide spectrum of noninfectious gastrointestinal pathology, causing considerable morbidity and mortality in CVID, where both etiology and effective therapy are under debate.

AREAS COVERED

This review will focus on the noninfectious inflammation in the GI tract in CVID patients, covering the both the upper and lower GI tract inflammation, including the liver. The controversy of the CVID enteropathy definition and that of gluten-free diet for celiac-like disease in CVID will be discussed. Furthermore, the review will cover the link between GI inflammation and GI cancer. Finally, the role of gut microbiota, IgA, and genetics and its relationship with CVID enteropathy is scrutinized. The authors reviewed literature from PubMed.

EXPERT OPINION

The heterogeneity and the unknown mechanism behind CVID enteropathy, and thereby the lack of effective treatment, is one of the key challenges in the field of CVID. Celiac-like disease in CVID is due to immune dysregulation, and a gluten-free diet is therefore not indicated. Gut microbial dysbiosis and mucosal IgA can initiate systemic and local inflammation and is involved in the immune dysregulation in CVID. Considering the heterogeneity of CVID enteropathy, personalized medicine is probably the future for these patients.

The PID Principles of Care: Where Are We Now? A Global Status Report Based on the PID Life Index

A global gold standard framework for primary immunodeficiency (PID) care, structured around six principles, was published in 2014. To measure the implementation status of these principles IPOPI developed the PID Life Index in 2020, an interactive tool aggregating national PID data. This development was combined with a revision of the principles to consider advances in the field of health and science as well as political developments since 2014. The revision resulted in the following six principles: PID diagnosis, treatments, universal health coverage, specialised centres, national patient organisations and registries for PIDs. A questionnaire corresponding to these principles was sent out to IPOPI’s national member organisations and to countries in which IPOPI had medical contacts, and data was gathered from 60 countries. The data demonstrates that, regardless of global scientific progress on PIDs with a growing number of diagnostic tools and better treatment options becoming available, the accessibility and affordability of these remains uneven throughout the world. It is not only visible between regions, but also between countries within the same region. One of the most urgent needs is medical education. In countries without immunologists, patients with PID suffer the risk of remaining undiagnosed or misdiagnosed, resulting in health implications or even death. Many countries also lack the infrastructure needed to carry out more advanced diagnostic tests and perform treatments such as hematopoietic stem cell transplantation or gene therapy. The incapacity to secure appropriate diagnosis and treatments affects the PID environment negatively in these countries. Availability and affordability also remain key issues, as diagnosis and treatments require coverage/reimbursement to ensure that patients with PID can access them in practice, not only in theory. This is still not the case in many countries of the world according to the PID Life Index. Although some countries do perform better than others, to date no country has fully implemented the PID principles of care, confirming the long way ahead to ensure an optimal environment for patients with PID in every country.

Derisking CD20-therapies for long-term use

Anti-CD20 have quickly become the mainstay in the treatment of multiple sclerosis (MS) and other neuroinflammatory conditions. However, when they are used as a maintenance therapy the balance between risks and benefits changes. In this review, we suggested six steps to derisk anti-CD20. Firstly and secondly, adequate infectious screening followed by vaccinations before starting anti-CD20 are paramount. Third, family planning needs to be discussed upfront with every woman of childbearing age. Fourth, infusion reactions should be adequately managed to avoid treatment interruption. After repeated infusions, it becomes important to detect and prevent anti-CD20-related adverse events. Fifth, we recommended measuring immunoglobulin levels and reviewing vaccinations annually as well as counselling adequate fever management. For female patients, we emphasised the importance to engage with the local breast cancer screening programs. Sixth, to fundamentally derisk anti-CD20 therapies, we need evidence-based approaches to reduce dosing intervals and guide retreatment.

Granulomatous-Lymphocytic Interstitial Lung Disease Mimicking Sarcoidosis

Common variable immunodeficiency (CVID) is one of the most common primary immunodeficiency disorders characterized by hypogammaglobulinemia and inadequate antibody response to immunizations. The impaired antibody response occurs due to the failure of B cells to differentiate into plasma cells resulting in low immunoglobulins levels and increased frequency of infections. Granulomatous and Lymphocytic Interstitial Lung Disease (GLILD) is a non-infectious complication of CVID that is seen in 10-30% of cases. GLILD is a multisystem inflammatory disease involving the lungs, lymph node, liver, spleen and gastrointestinal tract that mimics sarcoidosis. This report describes a series of cases who presented with dyspnea, recurrent respiratory infections or autoimmunity and on further evaluation revealed features suggestive of GLILD. There is very limited understanding of GLILD in terms of clinical presentation, the histo-pathological logical findings, and the diagnostic criteria by itself are limited. A diagnosis of GLILD is established in cases of CVID when there is evidence of lymphoproliferation, cytopenia, autoimmune processes and a lung biopsy demonstrating lymphocytic interstitial pneumonia, follicular bronchiolitis, lymphoid hyperplasia, and/or non-necrotizing granulomas. We review the treatment strategies, including replacement of immunoglobulin and agents targeting B and T lymphocytes. Systematic characterization of GLILD cases and long term follow up studies are sorely needed to understand the natural history of GLILD.

Common variable immunodeficiency disorders: What generalists should know

Primary immune deficiency disorders (PIDDs) are common and underdiagnosed. Predominant antibody deficiencies (PADs) are the most common type of immune deficiency and comprise 55% of the immune deficiencies diagnosed.^[1] Although immunoglobulin A (IgA) deficiency remains the most common type of PID, common variable immunodeficiency disorders remain the most common symptomatic PID for which medical therapy is sought.

Altered Plasma Fatty Acids Associate with Gut Microbial Composition in Common Variable Immunodeficiency

PURPOSE

Fatty acid (FA) abnormalities are found in various inflammatory disorders and have been related to disturbed gut microbiota. Patients with common variable immunodeficiency (CVID) have inflammatory complications associated with altered gut microbial composition. We hypothesized that there is an altered FA profile in CVID patients, related to gut microbial dysbiosis.

METHODS

Plasma FAs were measured in 39 CVID patients and 30 healthy controls. Gut microbial profile, a food frequency questionnaire, and the effect of the oral antibiotic rifaximin were investigated in CVID patients.

RESULTS

The n-3 polyunsaturated fatty acids (PUFAs), eicosapentaenoic acid (EPA) (1.4 [1.0-1.8] vs. 1.9 [1.2-2.5], median (IQR), P < 0.05), and docosahexaenoic acid (DHA) (3.2 [2.4-3.9] vs. 3.5 [2.9-4.3], P < 0.05), all values expressed as weight percent of total plasma FAs, were reduced in CVID compared to controls. Also, n-6 PUFAs (34.3 ± 3.4 vs. 37.1 ± 2.8, mean ± SD, P < 0.001) and linoleic acid (LA) (24.5 ± 3.3 vs. 28.1 ± 2.7, P < 0.0001) and the FA anti-inflammatory index (98.9 [82.1-119.4] vs. 117.0 [88.7-153.1], median (IQR), P < 0.05) were reduced in CVID. The microbial alpha diversity was positively associated with plasma n-6 PUFAs (r = 0.41, P < 0.001) and LA (r = 0.51, P < 0.001), but not n-3 PUFAs (P = 0.78). Moreover, a 2-week course of rifaximin significantly reduced the proportion of n-6 PUFAs (P = 0.04, UNIANOVA). Serum immunoglobulin G (IgG) levels correlated with plasma n-3 PUFAs (rho = 0.36, P = 0.03) and DHA (rho = 0.41, P = 0.009).

CONCLUSION

We found a potentially unfavorable FA profile in CVID, related to low IgG levels. High plasma n-6 PUFAs were related to increased gut microbial diversity and altered by rifaximin therapy.

Chronically Activated T-cells Retain Their Inflammatory Properties in Common Variable Immunodeficiency

Purpose

Immune dysregulation complications cause significant morbidity and mortality in common variable immunodeficiency (CVID), but the underlying pathophysiology is poorly understood. While CVID is primarily considered a B-cell defect, resulting in the characteristic hypogammaglobulinemia, T-cells may also contribute to immune dysregulation complications. Here, we aim to further characterize T-cell activation and regulation in CVID with immune dysregulation (CVIDid).

Methods

Flow cytometry was performed to investigate T-cell differentiation, activation and intracellular cytokine production, negative regulators of immune activation, regulatory T-cells (Treg), and homing markers in 12 healthy controls, 12 CVID patients with infections only (CVIDio), and 20 CVIDid patients.

Results

Both CD4 + and CD8 + T-cells in CVIDid showed an increased activation profile (HLA-DR + , Ki67 + , IFNγ +) when compared to CVIDio, with concomitant upregulation of negative regulators of immune activation PD1, LAG3, CTLA4, and TIGIT. PD1 + and LAG3 + subpopulations contained equal or increased frequencies of cells with the capacity to produce IFNγ, Ki67, and/or GzmB. The expression of PD1 correlated with serum levels of CXCL9, 10, and 11. Treg frequencies were normal to high in CVIDid, but CVIDid Tregs had reduced CTLA-4 expression, especially on CD27 + effector Tregs. Increased migratory capacity to inflamed and mucosal tissue was also observed in CVIDid T-cells.

Conclusion

CVIDid was characterized by chronic activation of peripheral T-cells with preserved inflammatory potential rather than functional exhaustion, and increased tissue migratory capacity. While Treg numbers were normal in CVIDid Tregs, low levels of CTLA-4 indicate possible Treg dysfunction. Combined studies of T-cell dysfunction and circulating inflammatory proteins may direct future treatment strategies.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10875-021-01084-6.

Chronic enteropathy-related malabsorption syndrome in an adult with common variable immunodeficiency and symptomatic norovirus infection of the gut

Common variable immunodeficiency (CVID) causes a chronic debilitating syndrome in affected patients and often leads to high morbidity and mortality. Among its several presentations, chronic enteropathy leading to malabsorption syndrome continues to offer a major diagnostic dilemma. Lately, higher testing for norovirus infection in patients with CVID enteropathy has correlated its presence to chronic diarrhoeas, severe villous atrophy and malabsorption syndromes. There have been no such reports of its clinical and histopathological manifestations in CVID from India. Here, we demonstrate the significance of testing for norovirus in the gut with multiplex PCRs in an adult patient with a chronic undiagnosed CVID enteropathy and its response to monthly intravenous immunoglobulin (IVIG) therapy. Our patient responded after three cycles of monthly IVIG with a complete clinical recovery of his bowel functions, leading to a significant improvement in his quality of life and performance status.

Late-onset and long-lasting autoimmune neutropenia: an analysis from the Italian Neutropenia Registry

Primary autoimmune neutropenia (pAN) is typified by onset in early infancy and a mild/moderate phenotype that resolves within 3 years of diagnosis. In contrast, secondary AN is classically an adult disease associated with malignancy, autoimmunity, immunodeficiency, viral infection, or drugs. This study describes a cohort of 79 children from the Italian Registry who, although resembling pAN, did not fully match the criteria for pAN because neutropenia either appeared after age 5 years (LO-Np) or lasted longer than 3 years (LL-Np). These 2 categories compared with classical pAN showed a far inferior rate of resolution (P < .001), lower severity of neutropenia (P = .03), leukopenia (P < .001), lymphopenia (P < .001) with low B+ (P = .001), increased need of granulocyte colony-stimulating factor (P = .04), and increased frequency of autoimmunity over the disease course (P < .001). A paired comparison between LO-Np and LL-Np suggested that LO-Np had a lower rate of resolution (P < .001) and lower white blood cell (P < .001) and lymphocyte (P < .001) values, higher occurrence of apthae (P = .008), and a stronger association with autoimmune diseases/markers (P = .001) than LL-Np, thus suggesting a more pronounced autoimmune signature for LO-Np. A next-generation sequencing panel applied in a small subgroup of LO-Np and LL-Np patients identified variants related to immune dysregulations. Overall, these findings indicate that there are important differences among pAN LL-Np and LO-Np. Forms rising after 3 years of age, with low tendency to resolution, require tight monitoring and extensive immune investigations aimed to early identify underlying immunologic disease.

Recurrent asthma exacerbations: co-existing asthma and common variable immunodeficiency

Common variable immunodeficiency is characterized by impaired B-cell differentiation and defective immunoglobulin production manifesting as recurrent respiratory tract infections. While the condition can masquerade as asthma, late diagnosis of CVID in known asthmatic is rarely reported.

We present the case of a 43-year-old lady with recurrent episodes of wheeze, cough, sinusitis and multiple lower respiratory tract infections. Transiently responsive to antibiotics and steroids. These episodes had been occurring for many years and she had a longstanding clinical diagnosis of asthma.

As part of her work up for recurrent respiratory tract infections a CT thorax was performed and demonstrated bronchiectasis. Further tests including Immunoglobulin levels revealed critically low IgG, IgM, and IgA levels. Immunoglobulin replacement therapy was commenced with a reduction in exacerbation frequency and severity, and objective improvement of asthma control. Subsequent lung function tests demonstrated reversible airflow limitation (obstructive lung function with 13% reversibility in FEV₁ post-bronchodilator) consistent with asthma.

Our case illustrates the importance of searching for alternate and co-existent diagnoses in patients diagnosed with asthma who are unresponsive to conventional therapy. We believe that serum immunoglobulin measurement should form a component of such a workup.

Perfluorooctanoic acid (PFOA) exposure induces splenic atrophy via overactivation of macrophages in male mice

Perfluorooctanoic acid (PFOA), a synthetic and widely used chemical, has aroused wide public concern due to its persistence, bioaccumulation, and potential toxicity. To investigate splenic atrophy induced by PFOA, male mice were exposed to 0, 0.4, 2, or 10 mg/kg/d PFOA for 28 d. Results demonstrated that spleen weight and relative spleen weight (RSW) decreased in the 2 and 10 mg/kg/d PFOA exposure groups. Iron levels in the spleen and serum were also reduced in all PFOA exposure groups. Weighted gene co-expression network analysis (WGCNA) of 7 043 genes highlighted enrichment in cell cycle, autoimmunity, and anemia in the spleen. In addition, changes in the levels of hemoglobin, platelets, bilirubin, and heme oxygenase-1 were consistent with anemia. The ratio of total macrophages to M1 macrophages in the spleen, phagocytic ability of macrophages, and levels of cytokines such as TNF-α, IL-1β, and IL-6 all increased, thus suggesting the occurrence of autoimmune disorder. Therefore, we concluded that overactivation of macrophages may be an important reason for splenic atrophy induced by PFOA exposure.

State-of-the-art diagnostic evaluation of common variable immunodeficiency

OBJECTIVE

To summarize the current understanding of diagnostic and postdiagnostic evaluation of common variable immunodeficiency (CVID).

DATA SOURCES

PubMed Central database.

STUDY SELECTIONS

Original research articles and review articles from 2015 to 2020 including seminal articles that shaped the diagnostic and postdiagnostic evaluation of CVID were incorporated. This work focuses on initial diagnosis of CVID, genetic evaluations, and postdiagnostic assessment of respiratory, gastrointestinal, and hepatobiliary diseases including spleen and lymph node enlargement.

RESULTS

CVID presents not only with frequent infections but also with noninfectious complications such as autoimmunity, gastrointestinal disease, chronic lung disease, granulomas, liver disease, lymphoid hyperplasia, splenomegaly, or malignancy. The risk of morbidity and mortality is higher in patients with CVID and noninfectious complications. Detailed diagnostic approaches, which may incorporate genetic testing, can aid characterization of individual CVID cases and shape treatment in some instances. Moreover, continued evaluation after CVID diagnosis is key to optimal management of this complex disorder. These postdiagnostic evaluations include pulmonary function testing, radiologic studies, and laboratory evaluations that may be conducted at frequencies determined by disease activity.

CONCLUSION

Although the diagnosis can be achieved similarly in all patients with CVID, those with noninfectious complications have distinct concerns during clinical evaluation. State-of-the-art workup of CVID with noninfectious complications typically includes genetic analysis, which may shape precision therapy, and thoughtful application of postdiagnostic tests that monitor the presence and progression of disease in the myriad of tissues that may be affected. Even with recent advancements, knowledge gaps in diagnosis, prognosis, and treatment of CVID persist, and continued research efforts are needed.

[Common variable immunodeficiency disorders: Part 2. Updated clinical manifestations and therapeutic management]

Common variable immunodeficiency disorders (CVID) are the most common symptomatic primary antibody deficiency in adults with an estimated prevalence of 1/25,000. The most frequent clinical manifestations are upper respiratory tract infections (including pneumonia, bronchitis, and sinusitis) predominantly with Streptococcus pneumoniae or H. influenzae. However, CVID are complicated in 20 to 30 % of cases of non-infectious manifestations which have been well characterized in recent years. Several complications can be observed including autoimmune, lymphoproliferative, granulomatous or cancerous manifestations involving one or more organs. These complications, mostly antibody-mediated cytopenias, are correlated with a decrease in the number of circulating switched memory B cells. Replacement therapy with polyvalent gammaglobulins has greatly improved the prognosis of these patients but it remains poor in the presence of digestive complications (especially in the case of chronic enteropathy and/or porto-sinusoidal vascular disease), pulmonary complications (bronchiectasis and/or granulomatous lymphocytic interstitial lung disease) and when progression to lymphoma. Much progress is still to be made, in particular on the therapeutic management of non-infectious complications which should benefit in the future from targeted treatments based on knowledge of genetics and immunology.

Gut Microbiota-Host Interactions in Inborn Errors of Immunity

Inborn errors of immunity (IEI) are a group of disorders that are mostly caused by genetic mutations affecting immune host defense and immune regulation. Although IEI present with a wide spectrum of clinical features, in about one third of them various degrees of gastrointestinal (GI) involvement have been described and for some IEI the GI manifestations represent the main and peculiar clinical feature. The microbiome plays critical roles in the education and function of the host's innate and adaptive immune system, and imbalances in microbiota-immunity interactions can contribute to intestinal pathogenesis. Microbial dysbiosis combined to the impairment of immunosurveillance and immune dysfunction in IEI, may favor mucosal permeability and lead to inflammation. Here we review how immune homeostasis between commensals and the host is established in the gut, and how these mechanisms can be disrupted in the context of primary immunodeficiencies. Additionally, we highlight key aspects of the first studies on gut microbiome in patients affected by IEI and discuss how gut microbiome could be harnessed as a therapeutic approach in these diseases.

Granulomatous-Lymphocytic Interstitial Lung Disease in Common Variable Immunodeficiency-Features of CT and 18F-FDG Positron Emission Tomography/CT in Clinically Progressive Disease

Common variable immunodeficiency (CVID) is characterized not only by recurrent bacterial infections, but also autoimmune and inflammatory complications including interstitial lung disease (ILD), referred to as granulomatous-lymphocytic interstitial lung disease (GLILD). Some patients with GLILD have waxing and waning radiologic findings, but preserved pulmonary function, while others progress to end-stage respiratory failure. We reviewed 32 patients with radiological features of GLILD from our Norwegian cohort of CVID patients, including four patients with possible monogenic defects. Nineteen had deteriorating lung function over time, and 13 had stable lung function, as determined by pulmonary function testing of forced vital capacity (FVC), and diffusion capacity of carbon monoxide (DLCO). The overall co-existence of other non-infectious complications was high in our cohort, but the prevalence of these was similar in the two groups. Laboratory findings such as immunoglobulin levels and T- and B-cell subpopulations were also similar in the progressive and stable GLILD patients. Thoracic computer tomography (CT) scans were systematically evaluated and scored for radiologic features of GLILD in all pulmonary segments. Pathologic features were seen in all pulmonary segments, with traction bronchiectasis as the most prominent finding. Patients with progressive disease had significantly higher overall score of pathologic features compared to patients with stable disease, most notably traction bronchiectasis and interlobular septal thickening. 18F-2-fluoro-2-deoxy-D-glucose (¹⁸F-FDG) positron emission tomography/CT (PET/CT) was performed in 17 (11 with progressive and six with stable clinical disease) of the 32 patients and analyzed by quantitative evaluation. Patients with progressive disease had significantly higher mean standardized uptake value (SUVmean), metabolic lung volume (MLV) and total lung glycolysis (TLG) as compared to patients with stable disease. Nine patients had received treatment with rituximab for GLILD. There was significant improvement in pathologic features on CT-scans after treatment while there was a variable effect on FVC and DLCO.

Conclusion

Patients with progressive GLILD as defined by deteriorating pulmonary function had significantly greater pathology on pulmonary CT and FDG-PET CT scans as compared to patients with stable disease, with traction bronchiectasis and interlobular septal thickening as prominent features.

Activated Phosphoinositide 3-Kinase Delta Syndrome 1: Clinical and Immunological Data from an Italian Cohort of Patients

Activated phosphoinositide 3-kinase delta syndrome 1 (APDS-1) is a recently described inborn error of immunity caused by monoallelic gain-of-function mutations in the PIK3CD gene. We reviewed for the first time medical records and laboratory data of eight Italian APDS-1 patients. Recurrent sinopulmonary infections were the most common clinical feature at onset of disease. Seven patients presented lymphoproliferative disease, at onset or during follow-up, one of which resembled hemophagocytic lymphohistiocytosis (HLH). Genetic analysis of the PIK3CD gene revealed three novel mutations: functional testing confirmed their activating nature. In the remaining patients, the previously reported variants p.E1021K (n = 4) and p.E525A (n = 1) were identified. Six patients were started on immunoglobulin replacement treatment (IgRT). One patient successfully underwent hematopoietic stem cell transplantation (HSCT), with good chimerism and no GVHD at 21 months post-HSCT. APDS-1 is a combined immune deficiency with a wide variety of clinical manifestations and a complex immunological presentation. Besides IgRT, specific therapies targeting the PI3Kδ pathway will most likely become a valid aid for the amelioration of patients’ clinical management and their quality of life.

Infectious Complications Reporting in Common Variable Immunodeficiency: A Systematic Review and Meta-analysis

Objectives

Common variable immunodeficiency (CVID) is a heterogeneous disorder characterized by hypogammaglobulinemia and increased susceptibility to recurrent infections.

Methods

We searched PubMed, Web of Science, and Scopus databases to find eligible studies from the earliest available date to January 2018 with standard keywords. Pooled estimates of the infection prevalence and the corresponding 95% confidence intervals were calculated using random-effects models.

Results

We found that pneumonia (67.7%) was the most prevalent infection followed by upper respiratory tract (59.0%) and gastrointestinal infections (36.3%). Furthermore, bacterial complications (41.7%) were higher in CVID patients compared to viral (25.4%), parasitic (18.8%), or fungal (3.4%) infections. Patients with longer age at diagnosis presented with fewer disease comorbidities. There was an inverse correlation between T lymphocyte count and viral infections. Moreover, we found that immunoglobulin M (IgM) serum level was inversely correlated with hepatitis C and gastrointestinal infections, and IgG serum level was inversely correlated with infectious arthritis. Higher numbers of CD4 and CD8 T cells were associated with the lower frequencies of otitis media. CVID patients with infections had significantly lower percentages of CD3 T cells. In contrast, higher percentages of CD19 lymphocytes were found in CVID patients who had a history of infections.

Conclusions

Our findings demonstrated that in addition to hypogammaglobulinemia, patients with CVID have an imbalance in the frequency of T lymphocytes, which is in parallel with the higher frequency of infectious complications.

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.

Renal Manifestations of Common Variable Immunodeficiency

BACKGROUND

Common variable immunodeficiency (CVID) is one of the most common primary immunodeficiency syndromes, affecting one in 25,000-50,000 people. Renal insufficiency occurs in approximately 2% of patients with CVID. To date, there are no case series of renal biopsies from patients with CVID, making it difficult to determine whether individual cases of renal disease in CVID represent sporadic events or are related to the underlying pathophysiology. We performed a retrospective analysis of renal biopsy specimens in our database from patients with a clinical history of CVID (n=22 patients, 27 biopsies).

METHODS

Light, immunofluorescence, and electron microscopy were reviewed. IgG subclasses, PLA2R immunohistochemistry, and THSD7A, EXT1, and NELL1 immunofluorescence were performed on all membranous glomerulopathy cases. CD3, CD4, CD8, and CD20 immunohistochemistry was performed on cases of tubulointerstitial nephritis.

RESULTS

AKI and proteinuria were the leading indications for renal biopsy in patients with CVID. Immune-complex glomerulopathy was present in 12 of 22 (54.5%) cases, including nine cases with membranous glomerulopathy, one case with a C3 glomerulopathy, and one case with membranoproliferative GN with IgG3κ deposits. All membranous glomerulopathy cases were PLA2R, THSD7A, EXT1, and NELL1 negative. The second most common renal biopsy diagnosis was chronic tubulointerstitial nephritis, affecting 33% of patients. All tubulointerstitial nephritis cases showed tubulitis and a lymphocytic infiltrate with >90% CD3⁺ T cells. Other renal biopsy diagnoses within our cohort included acute tubular injury (n=1), amyloid light-chain amyloidosis (n=1), diabetic glomerulosclerosis (n=1), thin basement membranes (n=1), pauci-immune GN (n=1), and arterionephrosclerosis (n=1).

CONCLUSIONS

Membranous glomerulopathy and tubulointerstitial nephritis were the predominant pathologic findings in patients with CVID. Membranous glomerulopathy cases in patients with CVID were IgG1 subclass dominant and showed mesangial immune deposits. Four of the membranous glomerulopathy cases had associated proliferation, with mesangial and/or endocapillary hypercellularity, with or without crescent formation. CVID should be considered as a potential cause when membranous glomerulopathy or chronic tubulointerstitial nephritis is seen in a young patient with a history of recurrent infections.