Pulmonary Disease Burden in Primary Immune Deficiency Disorders: Data from USIDNET Registry

IgD+IgM- B Cells in Common Variable Immunodeficiency

Common variable immunodeficiency (CVID) is the most frequent form of primary hypogammaglobulinemia in adults. In addition to recurrent infections and respiratory manifestations, CVID patients may present several non-infection complications such as autoimmune diseases. The mechanisms that lead to immune dysregulation in CVID are not completely understood. Given the role of IgD on naïve B cells in the maintenance of tolerance and secreted IgD in the respiratory mucosa, we evaluated the frequency of IgD+ naïve and IgD+ memory B cells in CVID patients. Here, no differences were observed in the percentages and proliferative responses of anergic IgD+IgM-CD27- B cells between CVID patients, with or without autoimmune disease, and the control group. Interestingly, in the compartment of memory B cells, the percentage of IgD+IgM- cells was higher only in CVID patients with allergic rhinitis/allergic asthma. Our results may indicate that anergic IgD+IgM-CD27- B cells may not be compromised in our CVID cohort. However, IgD+IgM- memory B cells may play a role in the immunopathogenesis of allergic rhinitis/allergic asthma in CVID patients. Further studies are needed to better understand the participation of IgD+IgM- memory B cells in the immunopathogenesis of allergic rhinitis/allergic asthma in CVID patients.

Endotypes in bronchiectasis: moving towards precision medicine. A narrative review

Bronchiectasis is a highly complex entity that can be very challenging to investigate and manage. Patients are diverse in their aetiology, symptoms, risk of complications and outcomes. "Endotypes"- subtypes of disease with distinct biological mechanisms, has been proposed as a means of better managing bronchiectasis. This review discusses the emerging field of endotyping in bronchiectasis. We searched PubMed and Google Scholar for randomized controlled trials (RCT), observational studies, systematic reviews and meta-analysis published from inception until October 2022, using the terms: "bronchiectasis", "endotypes", "biomarkers", "microbiome" and "inflammation". Exclusion criteria included commentaries and non-English language articles as well as case reports. Duplicate articles between databases were initially identified and appropriately excluded. Studies identified suggest that it is possible to classify bronchiectasis patients into multiple endotypes deriving from their co-morbidities or underlying causes to complex infective or inflammatory endotypes. Specific biomarkers closely related to a particular endotype might be used to determine response to treatment and prognosis. The most clearly defined examples of endotypes in bronchiectasis are the underlying causes such as immunodeficiency or allergic bronchopulmonary aspergillosis where the underlying causes are clearly related to a specific treatment. The heterogeneity of bronchiectasis extends, however, far beyond aetiology and it is now possible to identify subtypes of disease based on inflammatory mechanisms such airway neutrophil extracellular traps and eosinophilia. In future biomarkers of host response and infection, including the microbiome may be useful to guide treatments and to increase the success of randomized trials. Advances in the understanding the inflammatory pathways, microbiome, and genetics in bronchiectasis are key to move towards a personalized medicine in bronchiectasis.

Respiratory Comorbidities Associated with Bronchiectasis in Patients with Common Variable Immunodeficiency in the USIDNET Registry

BACKGROUND

Bronchiectasis is a major respiratory complication in patients with common variable immunodeficiency (CVID) and is associated with recurrent pulmonary infections. However, it is unclear whether other infections or non-infectious respiratory conditions are related to its development.

OBJECTIVE

To identify respiratory comorbidities associated with bronchiectasis in patients with CVID.

METHODS

A total of 1470 CVID patients enrolled in the USIDNET registry were included in a cross-sectional analysis. The primary outcome of our study was to determine the clinical characteristics and other respiratory conditions associated with respiratory comorbidities and physician-reported bronchiectasis.

RESULTS

One hundred ninety-seven CVID patients were noted to have bronchiectasis (13.4%). Affected patients were significantly older than patients without bronchiectasis (median age 54 years vs. 49 years, p = 0.0004). These patients also had lower serum IgA (13 mg/dL IQR 60 mg/dL vs. 28.4 mg/dL IQR 66 mg/dL, p = 0.000). Notably, chronic rhinosinusitis (OR = 1.69 95%CI 1.05-2.75), sinusitis (OR = 2.06 95%CI 1.38-3.09), pneumonia (OR = 2.70 95%CI 1.88-3.88), COPD (OR = 2.66 95%CI 1.51-4.67), and interstitial lung disease (OR = 2.34 95%CI 1.41-3.91) were independently associated with the development of bronchiectasis in this population.

CONCLUSION

These data suggest that lower and upper respiratory infections, chronic lower airway disease, and interstitial lung diseases are independently associated with bronchiectasis in CVID patients. Further study into predisposing conditions related to the development of bronchiectasis in CVID patients may allow prediction and early intervention strategies to prevent the development of this complication.

Mid-Regional Proadrenomedullin Levels in Primary Immunodeficiencies Complicated with Pulmonary Manifestations

The development of lower respiratory complications in children with primary immunodeficiencies characterized by recurrent infections significantly contributes to morbidity and mortality. This is clinically more important and specific in the evaluation of prognosis. The inflammatory response that develops throughout the clinical process can cause the release of several biomarkers. This study aimed to evaluate the inflammatory biomarker "mid-regional pro-adrenomedullin (MR-proADM)" levels by distribution of lower respiratory tract complications. Plasma MR-proADM levels were measured in children with (n = 52) and without (n = 103) lower respiratory tract complications. The complicated group was also evaluated as "infective and non-infective" groups. The median MR-proADM levels were higher in the complicated cases (p = 0.175). It was 205.5 (73.4- 562.6) ng/L in the infective group while it was 96.1 (26.1-43.3) ng/L in the non-infective group and the difference between the two groups was statistically significant (p = 0.003). The predictive value of MR-proADM (AUC = 0.749, p = 0.003) was statistically significant compared to CRP (AUC = 0.330, p = 0.040) and SAA (AUC = 0.261, p = 0.004) in the infective group. This study evidences that the MR-proADM levels are higher in PID cases with infective pulmonary complications. Among other markers, MR-proADM appears to be a particularly good predictive inflammation marker for these children.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12291-022-01061-9.

Current Issues in the Management of IgG Subclass Deficiencies in Adults With Chronic Respiratory Diseases

Primary immunodeficiency diseases (PIDs) are uncommon in adults; however, immunoglobulin G subclass deficiency (IGGSCD) is often found in a subset of adult patients with chronic respiratory diseases. As quantitative laboratory tests are used to diagnose IGGSCD, the clinical significance of IGGSCD remains controversial. However, respiratory infection is a common presenting feature of IGGSCD, and respiratory complications are responsible for subsequent morbidities, such as severe asthma, bronchiectasis, chronic obstructive airway diseases, and mortality. This review summarizes the current epidemiological data for PIDs, focusing on IGGSCD in the adult population. In addition, the investigation, treatment, and management strategies are detailed, including distinct issues faced by patients with chronic airway disease and their physicians in the proper diagnosis and treatment of IGGSCD.

Risk of somatic diseases in patients with eating disorders: the role of comorbid substance use disorders

AIMS

Eating disorders (EDs) and substance use disorders (SUDs) often co-occur, and both involve somatic diseases. So far, no study has considered whether comorbid SUDs may impact somatic disease risk in patients with EDs. Therefore, this study aimed to examine the impact of comorbid SUDs on the risk of 11 somatic disease categories in patients with anorexia nervosa (AN), bulimia nervosa (BN) and unspecified eating disorder (USED) compared to matched controls.

METHODS

A retrospective cohort study was conducted using Danish nationwide registries. The study population included 20 759 patients with EDs and 83 036 controls matched on month and year of birth, sex and ethnicity. Hazard ratios (HRs) were calculated to compare the risk of being diagnosed with a somatic disease (within 11 categories defined by the ICD-10) following first ED diagnosis (index date) between ED patients and controls both with and without SUDs (alcohol, cannabis or hard drugs).

RESULTS

The ED cohort and matched controls were followed for 227 538 and 939 628 person-years, respectively. For ED patients with SUDs, the risk pattern for being diagnosed with different somatic diseases (relative to controls without SUDs) varied according to type of ED and SUD [adjusted HRs ranged from 0.95 (99% CI = 0.57; 1.59) to 4.17 (2.68, 6.47)]. The risk estimates observed among ED patients with SUDs were generally higher than those observed among ED patients without SUDs [adjusted HRs ranged from 1.08 (99% CI = 0.95, 1.22) to 2.56 (2.31, 2.84)]. Abuse of alcohol only had a non-synergistic effect on six disease categories in AN patients and five in BN and USED patients. Abuse of cannabis (with/without alcohol) had a non-synergistic effect on five disease categories in AN and BN patients and two in USED patients. Abuse of hard drugs (with/without alcohol or cannabis) had a non-synergistic effect on nine disease categories in AN patients, eight in BN patients and seven in USED patients.

CONCLUSIONS

The present study documents non-synergistic but not synergistic harmful somatic consequences of SUDs among patients with different EDs, with AN and hard drugs being the most predominant factors. Hence, EDs and SUDs did not interact and result in greater somatic disease risk than that caused by the independent effects. Since EDs and SUDs have independent effects on many somatic diseases, it is important to monitor and treat ED patients for SUD comorbidity to prevent exacerbated physical damage in this vulnerable population.

Bronchial inflammation biomarker patterns link humoral immunodeficiency with bronchiectasis-related small airway dysfunction

BACKGROUND

The progression of chronic destructive lung disease in patients with humoral immunodeficiency (ID) and concomitant development of bronchiectasis is difficult to prevent. Lung function tests in these patients typically show bronchial obstruction of the small airways in combination with increased air trapping in the distal airways, which is consistent with small airway dysfunction.

OBJECTIVE

The objective was to assess the grade of chronic lower airway inflammation and small airway dysfunction from induced sputum and the corresponding local pro-inflammatory mediator pattern to discriminate patients affected by bronchiectasis-related Small Airway Dysfunction (SAD).

METHODS

In a prospective design, 22 patients with ID (14 CVID, 3 XLA, 3 hyper-IgM syndrome, 1 hyper-IgE syndrome and low IgG levels due to treatment with rituximab and 1 SCID after BMT and persistent humoral defect) and 21 healthy controls were examined. Lung function, Fraction Expiratory Nitric Oxide (FeNO) and pro-inflammatory cytokine levels were compared in subsets of patients with (ID + BE) and without bronchiectasis (ID) pre-stratified using high-resolution computed tomography (HRCT) scans and control subjects.

RESULTS

Analysis of induced sputum showed significantly increased total cell counts and severe neutrophilic inflammation in ID. The concomitant SAD revealed higher total cell numbers compared to ID. Bronchial inflammation in ID is clearly mirrored by pro-inflammatory mediators IL-1β, IL-6 and CXCL-8, whilst TNF-α revealed a correlation with lung function parameters altered in the context of bronchiectasis-related Small Airway Dysfunction.

CONCLUSIONS

In spite of immunoglobulin substitution, bronchial inflammation was dominated by neutrophils and was highly increased in patients with ID + BE. Notably, the pro-inflammatory cytokines in patients with ID were significantly increased in induced sputum. The context-dependent cytokine pattern in relation to the presence of concomitant bronchiectasis associated with SAD in ID patients could be helpful in delimiting ID patient subgroups and individualizing therapeutic approaches.

Progressive Depletion of B and T Lymphocytes in Patients with Ataxia Telangiectasia: Results of the Italian Primary Immunodeficiency Network

Ataxia telangiectasia (AT) is a rare neurodegenerative genetic disorder due to bi-allelic mutations in the Ataxia Telangiectasia Mutated (ATM) gene. The aim of this paper is to better define the immunological profile over time, the clinical immune-related manifestations at diagnosis and during follow-up, and to attempt a genotype–phenotype correlation of an Italian cohort of AT patients. Retrospective data of 69 AT patients diagnosed between December 1984 and November 2019 were collected from the database of the Italian Primary Immunodeficiency Network. Patients were classified at diagnosis as lymphopenic (Group A) or non-lymphopenic (Group B). Fifty eight out of 69 AT patients (84%) were genetically characterized and distinguished according to the type of mutations in truncating/truncating (TT; 27 patients), non-truncating (NT)/T (28 patients), and NT/NT (5 patients). In 3 patients, only one mutation was detected. Data on age at onset and at diagnosis, cellular and humoral compartment at diagnosis and follow-up, infectious diseases, signs of immune dysregulation, cancer, and survival were analyzed and compared to the genotype. Lymphopenia at diagnosis was related per se to earlier age at onset. Progressive reduction of cellular compartment occurred during the follow-up with a gradual reduction of T and B cell number. Most patients of Group A carried bi-allelic truncating mutations, had a more severe B cell lymphopenia, and a reduced life expectancy. A trend to higher frequency of interstitial lung disease, immune dysregulation, and malignancy was noted in Group B patients. Lymphopenia at the onset and the T/T genotype are associated with a worst clinical course. Several mechanisms may underlie the premature and progressive immune decline in AT subjects.

Respiratory system findings in pediatric patients with primary immunodeficiency

BACKGROUND

Pulmonary involvement which can be infectious or noninfectious is one of the most frequent complications in patients with primary immunodeficiency (PID).

OBJECTIVE

The aim of this study is to assess the pulmonary system of the pediatric patients with PID and report the demographical, clinical, and radiological findings regarding the underlying PID.

METHODS

The present study included pediatric patients who were receiving immunoglobulin replacement therapy (IGRT) for PID (combined immunodeficiency [CVID] (23), common variable immunodeficiency (15), and agamaglobulinemia [10]) so far or newly diagnosed and started IGRT at Hacettepe University Immunology Department, between January 2015 and January 2018.

RESULTS

A total of 48 patients (60.4% male), aged 9.9 (6.1-14) years were included. Time of delay in the diagnosis of immundeficiency was 2.27 (interquartile range: 1.0-6.75) years. CVID patients exhibited higher respiratory system symptoms, as well as a history of recurrent lung infection and hospitalization. Hilar and mediastinal lymphadenopathies, peribronchial thickening, and bronchiectasis were the most common pulmonary complications and more than three lung lobes were affected in 69%. Among the newly diagnosed patients, bronchiectasis was present in 25% and more than three lobes were affected in 62.5%. Although pulmonary nodules and mediastinal lymphadenopathy were frequently computed tomography findings in our patients, only two patients (4.16%) were diagnosed with interstitial lung disease.

CONCLUSION

Although bronchiectasis is predominantly reported as a long-term complication in adult patients with PID, half of our pediatric patient cohort with PID had bronchiectasis, even the newly diagnosed patients. Long-term follow-up is needed to assess the extent to which these pulmonary complications that develop in the natural course of the disease can be prevented by IGRT.

Common Variable Immunodeficiency and Other Immunodeficiency Syndromes in Bronchiectasis

Immunodeficiency represents a vast number of diseases and syndromes. Both primary and secondary forms of immunodeficiency are important contributors to the development of bronchiectasis. Primary immune deficiencies, in particular, are increasingly identified and defined as contributors. Specific immune deficiencies that are closely associated with bronchiectasis and as discussed in this article are common variable immunodeficiency, specific antibody deficiency, immunodeficiencies involving immunoglobulin E, DOCK8 immunodeficiency, phosphoglucomutase 3 deficiency, activated phosphoinositide 3-kinase delta syndrome, and X-linked agammaglobulinemia. Each of these primary immune deficiencies has unique nuances. Vigilance for these unique signs and symptoms is likely to improve recognition of specific immunodeficiency in the idiopathic bronchiectasis patient. Secondary forms of immunodeficiency occur as a result of a separate disease process. Graft versus host disease, malignancy, and human immunodeficiency virus are three classic examples discussed in this article. An awareness of the potential for these disease settings to lead to bronchiectasis is necessary to optimize patient care. With understanding and mindfulness toward the intricate relationship between bronchiectasis and immunodeficiency, there is an opportunity to elucidate pathophysiologic underpinnings between these two syndromes.

Echocardiography Monitoring of Pulmonary Hypertension after Pediatric Hematopoietic Stem Cell Transplantation: Pediatric Pulmonary Arterial Hypertension and Pulmonary Veno-Occlusive Disease after Hematopoietic Stem Cell Transplantation

Pulmonary hypertension (PH) is associated with high morbidity in children undergoing hematopoietic stem cell transplantation (HSCT). However, owing to the lack of sequential echocardiography, the nature of the condition is not fully understood. This study was conducted to investigate whether routine echocardiography performed after HSCT could detect patients with PH at an earlier stage and elucidate the role of intervention using tadalafil. The study population comprised 93 consecutive children age <18 years who underwent a total of 109 HSCTs. All patients underwent routine transthoracic echocardiography during HSCT. Four children (4%) with a median age of 4 years (range, 0.7 to 6 years) were found to have PH, and their median tricuspid regurgitation peak velocity (TRV) was 4.1 m/s (range, 3.5 to 4.2 m/s). PH was diagnosed at a median of 52 days (range, 21 to 118 days) after HSCT. Three of them were diagnosed with neuroblastoma, and 1 was diagnosed with infantile leukemia. One patient developed PH after autologous HSCT, and 3 received killer immunoglobulin-like receptor ligand-mismatched cord blood. Busulfan was used for conditioning in all patients, and the proportion of patients receiving this medication was significantly higher in the PH group compared with the non-PH group (100% versus 30%; P = .011). Three of the 4 patients had a durable response (TRV ≤2.8 m/s) at a median of 46 days (range, 14 to 79 days) after starting treatment with tadalafil. No patient experienced exacerbation of PH, and treatment was completed at median of 96 days (range, 46 to 212 days). Our data suggest that routine echocardiography monitoring after HSCT should be considered in children receiving busulfan, although the precise follow-up timing needs further study. In addition, safe and effective administration of tadalafil must be ensured by close monitoring.

Pulmonary Manifestations of Immunodeficiency and Immunosuppressive Diseases Other than Human Immunodeficiency Virus

Immune deficiencies may alter normal lung function and protective mechanisms, resulting in a myriad of pulmonary manifestations. Primary immunodeficiencies involve multiple branches of the immune system, and defects may predispose to recurrent upper and lower respiratory infections by common pathogens; opportunistic infections; and autoimmune, inflammatory, and malignant processes that may result in interstitial pneumonias. Secondary immunodeficiencies may result from neoplasms or their treatment, organ transplant and immunosuppression, and from autoimmune diseases and their treatments. Primary and secondary immunodeficiencies and their pulmonary manifestations may be difficult to diagnose and treat. A multidisciplinary approach to evaluation is essential.

Digital systems for improving outcomes in patients with primary immune defects

PURPOSE OF REVIEW

Healthcare has already been impacted by the fourth industrial revolution exemplified by tip of spear technology, such as artificial intelligence and quantum computing. Yet, there is much to be accomplished as systems remain suboptimal, and full interoperability of digital records is not realized. Given the footprint of technology in healthcare, the field of clinical immunology will certainly see improvements related to these tools.

RECENT FINDINGS

Biomedical informatics spans the gamut of technology in biomedicine. Within this distinct field, advances are being made, which allow for engineering of systems to automate disease detection, create computable phenotypes and improve record portability. Within clinical immunology, technologies are emerging along these lines and are expected to continue.

SUMMARY

This review highlights advancements in digital health including learning health systems, electronic phenotyping, artificial intelligence and use of registries. Technological advancements for improving diagnosis and care of patients with primary immunodeficiency diseases is also highlighted.

Infection Phenotypes Among Patients with Primary Antibody Deficiency Mined from a US Patient Registry

PURPOSE

Primary immunodeficiency disorders (PIDs) affect immune system development and/or function, increase infection susceptibility, and cause dysregulation or both. Recognition of PID requires assessment about the normal state of infection frequency and microbiology. To help clarify infection characteristics, we use data mined from the US Immunodeficiency Network (USIDNET) registry among primary antibody deficiency (PAD) patients before diagnosis.

METHODS

We analyzed PAD patient data from the USIDNET registry prior to ultimate diagnosis. Our analysis included basic descriptive statistics for 8 major infection subtypes and significance testing for comparing infection rate by specific organisms across 7 distinct PAD subtypes.

RESULTS

Of 2038 patients reviewed, 1259 (61.8%) had infections reported prior to diagnosis. Most (77.4%) had four or less reported infections prior to diagnosis; however, some suffered up to 16 infections. Infection patterns differed across the PAD subtypes. Patients with agammaglobulinemia differed significantly from patients with all other forms of PAD studied in at least one infection category, whereas patients with CVID differed from 3 other PAD categories in at least one infection category. Patterns of infections in patients with hypogammaglobulinemia, specific antibody deficiency, and transient hypogammaglobulinemia were less unique. For each of the infection types, bacteria were the most prevalent cause of disease.

CONCLUSIONS

Our data shows that distinct subtypes of PAD display unique infection patterns. We also show that patients with agammaglobulinemia suffer more invasive infections and differ most significantly from all other forms of PAD studied. Our analysis has broad implications about infection surveillance, progression, and vulnerability by PAD subtype.

From infections to autoimmunity: Diagnostic challenges in common variable immunodeficiency

Common variable immunodeficiency (CVID) is the most common clinically significant primary antibody deficiency diagnosed in adults. The early symptoms are not specific. They include common infections, mainly of the respiratory tract, caused by typical microorganisms, so cases can be missed in primary care. In the majority of patients increased susceptibility to infections coexists with signs or symptoms of autoimmunity, inflammation or polyclonal lymphoproliferation, which can divert diagnosis from immune deficiency. The overall incidence of malignancy is increased in CVID and certain cancers are significantly more common. Lymphomas and gastric carcinoma are the most frequently reported malignancies in CVID, so a high index of suspicion is recommended. Diagnostic delay in CVID is seen worldwide. The main goal of this paper is to increase the awareness about CVID among health care professionals. We aim to present features which can be helpful in CVID diagnosis in order to shorten the “latency” of proper management of CVID patients. We review clinical symptoms, complications and laboratory abnormalities of CVID. Immunoglobulin replacement therapy is regarded as the cornerstone of pharmacological intervention. New modes of Ig application, mainly subcutaneously and via the hyaluronidase-facilitated subcutaneous route, help to adjust therapy to patients’ needs and preferences. Still there remain unmet needs. It remains to be seen whether CVID complications can be avoided by earlier diagnosis, treatment and thorough monitoring in the context of increased risk of malignancy. Development of patient tailored protocols depending on the clinical phenotype and risk factors might be more appropriate. The most important consideration is to diagnose suspected cases and stratify patients in a precise and timely way. Work is needed to define features predictive of unfavorable prognosis.