Clinical immunology review series: An approach to the management of pulmonary disease in primary antibody deficiency

Risk Factors of Pneumonia in Primary Antibody Deficiency Patients Receiving Immunoglobulin Therapy: Data from the US Immunodeficiency Network (USIDNET)

BACKGROUND

Despite immunoglobulin replacement (IgRT) therapy, some patients with primary antibody deficiency (PAD) continue to develop respiratory infections. Recurrent and severe respiratory infections, particularly pneumonia, can lead to significant morbidity and mortality. Therefore, we sought to determine the risk factors of developing pneumonia in PAD patients, already receiving IgRT.

METHODS

We evaluated clinical and laboratory features of PAD patients enrolled in the US Immune Deficiency Network (USIDNET) registry by April 2017. Patients were included if they met the following criteria: (1) PAD diagnosis (common variable immunodeficiency (CVID), agammaglobulinemia, hypogammaglobinemia, and specific antibody deficiency (SAD) and (2) available data on infections before and after IgRT. Patients were excluded if they were not receiving IgRT, or if no pre/post infections data were available. Descriptive and multivariable logistic regression analyses were used to identify factors associated with pneumonia post-IgRT.

RESULTS

A total of 1232 patients met the inclusion criteria. Following IgRT, 218 patients (17.7%) were reported to have at least one pneumonia episode. Using multivariate logistic regression analysis, we found a statistically significant increased risk of pneumonia in patients with asthma (OR: 2.55, 95% CI (1.69-3.85), p < 0.001) bronchiectasis (OR: 3.94, 95% CI (2.29-6.80), p < 0.001), interstitial lung disease (ILD) (OR: 3.28, 95%CI (1.43-7.56), p < 0.005), splenomegaly (OR: 2.02, 95%CI (1.08-3.76), p < 0.027), allergies (OR: 2.44, 95% CI [1.44-4.13], p = 0.001), and patients who were not on immunosuppressives (OR: 1.61; 95%CI [1.06-2.46]; p = 0.027). For every 50 unit increase in IgA, the odds of reporting pneumonia post IgRT decreased (OR: 0.86, 95% CI [0.73-1.02], p = 0.062). Infectious organisms were reported in 35 of 218 patients who reported pneumonia after IgRT. Haemophilus influenzae was the most frequently reported (n = 11, 31.43%), followed by Streptococcus pneumoniae (n = 7, 20.00%).

CONCLUSION

Our findings suggest PAD patients with chronic and structural lung disease, splenomegaly, and allergies were associated with persistent pneumonia. However, our study is limited by the cross-sectional nature of the USIDNET database and limited longitudinal data. Further studies are warranted to identify susceptible causes and explore targeted solutions for prevention and associated morbidity and mortality.

CLINICAL IMPLICATIONS

Patients with primary antibody deficiency with structural lung disease, allergies, and splenomegaly are associated with persistent pneumonia post-IgRT.

Bispecific antibody therapy, its use and risks for infection: Bridging the knowledge gap

Relapsed haematological malignancies have a poor disease prognosis with current therapies. Bispecific antibodies (BsAbs) are becoming increasingly recognised for their efficacy in the treatment of these malignancies and are approved for the treatment of B-cell acute lymphoblastic leukaemia (B-ALL). BsAbs are manufactured to consist two variable chain fragments combined by a peptide linker amongst other structures to increase the half-life of the molecules. BsAbs function by bringing targeted tumour cells in close proximity of T-cells to allow killing via perforin and granzyme release. The increasing numbers of trials of BsAbs has highlighted their toxicity profile, including cytokine release syndrome (CRS), cytopaenia and hypogammaglobulinemia - which all increase risks for infection. The patterns and risks for infections with these novel agents remain unclear. This review article provides an overview of the risks of infection with various BsAbs platforms. A review of clinical trials reveals rates of infections amongst patients on BsAbs between 15 and 45% with a high proportion grade 3 severity or higher. A predominance of bacterial respiratory and line-related infections were identified amongst all haematological malignancies. In particular, high rates of febrile neutropaenia were identified in use of BsAbs in myeloid malignancy. Infection patterns identified in this review are utilised to inform infection prevention practice, including focused infection screening, line management, prophylaxis and vaccination strategies. Prophylaxis strategies against Pneumocystis pneumonia, herpes simplex and herpes zoster, candida and mould infections are considered, along with vaccination strategies against respiratory viral and bacterial infections. The long-term impacts of BsAbs on the immune system continue to be established.

X-linked Agammaglobulinemia Presenting with Multiviral Pneumonia

X-linked agammaglobulinemia (XLA) is a primary humoral immunodeficiency characterized by severe hypogammaglobulinemia and increased risk of infection. The genetic condition results from a mutation in the Bruton tyrosine kinase (BTK) gene located on the X chromosome leading to a near absence of B cells. Patients affected by XLA are most commonly predisposed to frequent and severe bacterial infections. However, here we report the case of a 20-year-old male with XLA who presented with viral pneumonia with multiple pathogens. This coexistence has been rarely reported. The patient received intravenous immunoglobulin therapy with noted significant improvement in the two weeks of follow-up. His clinical history supports the hypothesis of increased susceptibility to viral pathogens in the absence of immunoglobulin therapy. The humoral defect is the cornerstone of this phenomenon. This case presents the importance of multiviral causes for patients with recurrent episodes of pneumonia in an immunocompromised state.

Bronchiectasis in Primary Antibody Deficiencies: A Multidisciplinary Approach

Bronchiectasis, the presence of bronchial wall thickening with airway dilatation, is a particularly challenging complication of primary antibody deficiencies. While susceptibility to infections may be the primary factor leading to the development of bronchiectasis in these patients, the condition may develop in the absence of known infections. Once bronchiectasis is present, the lungs are subject to a progressive cycle involving both infectious and non-infectious factors. If bronchiectasis is not identified or not managed appropriately, the cycle proceeds unchecked and yields advanced and permanent lung damage. Severe symptoms may limit exercise tolerance, require frequent hospitalizations, profoundly impair quality of life (QOL), and lead to early death. This review article focuses on the appropriate identification and management of bronchiectasis in patients with primary antibody deficiencies. The underlying immune deficiency and the bronchiectasis need to be treated from combined immunology and pulmonary perspectives, reflected in this review by experts from both fields. An aggressive multidisciplinary approach may reduce exacerbations and slow the progression of permanent lung damage.

Appropriate lung management in patients with primary antibody deficiencies

Introduction: Human primary immunodeficiency diseases (PIDs) include a broad spectrum of more than 350 disorders, involving different branches of the immune system and classified as 'rare diseases.' Predominantly antibody deficiencies (PADs) represent more than half of the PIDs diagnosed in Europe and are often diagnosed in the adulthood. Areas covered: Although PAD could first present with autoimmune or neoplastic features, respiratory infections are frequent and respiratory disease represents a relevant cause of morbidity and mortality. Pulmonary complications may be classified as infection-related (acute and chronic), immune-mediated, and neoplastic. Expert opinion: At present, no consensus guidelines are available on how to monitor and manage lung complications in PAD patients. In this review, we will discuss the available diagnostic, prognostic and therapeutic instruments and we will suggest an appropriate and evidence-based approach to lung diseases in primary antibody deficiencies. We will also highlight the possible role of promising new tools and strategies in the management of pulmonary complications. However, future studies are needed to reduce of diagnostic delay of PAD and to better understand lung diseases mechanisms, with the final aim to ameliorate therapeutic options that will have a strong impact on Quality of Life and long-term prognosis of PAD patients.

Primary immunodeficiency diseases in lung disease: warning signs, diagnosis and management

Background

Pulmonary complications are common in primary immunodeficiency diseases (PID) and contribute to morbidity and mortality in these patients. However, their varied presentation and a general lack of awareness of PID in this setting make early diagnosis and treatment difficult. The aim of this study was to define the warning signs of PID in patients with respiratory manifestations, the necessary diagnostic tests, and the therapeutic management of both children and adults.

Methods

A review of the literature was performed, and 43 PID interdisciplinary specialists were consulted.

Results

This document identifies the pulmonary and extrapulmonary manifestations that should prompt a suspicion of PID, the immunological and respiratory tests that should be included in the diagnostic process according to the level of care, recommendations regarding the use of immunoglobulin replacement therapy according to the specific immunodeficiency, and the minimum recommended immunological and pulmonary monitoring in these patients.

Conclusions

This document is the first to combine scientific evidence with the opinion of a broad panel of experts specializing in the treatment of patients with immunodeficiencies. It aims to provide a useful tool for all practitioners who are regularly involved in the management of these patients.

The broad spectrum of lung diseases in primary antibody deficiencies

Human primary immunodeficiency diseases (PIDs) represent a heterogeneous group of more than 350 disorders. They are rare diseases, but their global incidence is more relevant than generally thought. The underlying defect may involve different branches of the innate and/or adaptive immune response. Thus, the clinical picture may range from severe phenotypes characterised by a broad spectrum of infections to milder infectious phenotypes due to more selective (and frequent) immune defects. Moreover, infections may not be the main clinical features in some PIDs that might present with autoimmunity, auto-inflammation and/or cancer. Primary antibody deficiencies (PADs) represent a small percentage of the known PIDs but they are the most frequently diagnosed, particularly in adulthood. Common variable immunodeficiency (CVID) is the most prevalent symptomatic PAD.

PAD patients share a significant susceptibility to respiratory diseases that represent a relevant cause of morbidity and mortality. Pulmonary complications include acute and chronic infection-related diseases, such as pneumonia and bronchiectasis. They also include immune-mediated interstitial lung diseases, such as granulomatous-lymphocytic interstitial lung disease (GLILD) and cancer. Herein we will discuss the main pulmonary manifestations of PADs, the associated functional and imaging findings, and the relevant role of pulmonologists and chest radiologists in diagnosis and surveillance.

The spectrum of lung complications in primary antibody deficiency ranges from asthma or COPD to extremely rare and specific ILDs. Early diagnosis of the underlying immune defect might significantly improve patients' lung disease, QoL and long-term prognosis.http://ow.ly/5cP230kZvOB

The Role of the Immune Response in the Pathogenesis of Bronchiectasis

Bronchiectasis is a prevalent respiratory condition characterised by permanent and abnormal dilation of the lung airways (bronchi). There are a large variety of causative factors that have been identified for bronchiectasis; all of these compromise the function of the immune response to fight infection. A triggering factor may lead to the establishment of chronic infection in the lower respiratory tract. The bacteria responsible for the lower respiratory tract infection are usually found as commensals in the upper respiratory tract microbiome. The consequent inflammatory response to infection is largely responsible for the pathology of this condition. Both innate and adaptive immune responses are activated. The literature has highlighted the central role of neutrophils in the pathogenesis of bronchiectasis. Proteases produced in the lung by the inflammatory response damage the airways and lead to the pathological dilation that is the pathognomonic feature of bronchiectasis. The small airways demonstrate infiltration with lymphoid follicles that may contribute to localised small airway obstruction. Despite aggressive treatment, most patients will have persistent disease. Manipulating the immune response in bronchiectasis may potentially have therapeutic potential.

Respiratory manifestations and management in children with Common Variable Immunodeficiency

Common variable immunodeficiency is an antibody deficiency that usually presents in childhood with recurrent sino-pulmonary infections. Diagnostic delay is frequent and thus respiratory morbidity is common, ranging from recurrent suppurative bronchitis to bronchiectasis. Immunoglobulin replacement therapy is the mainstay of treatment, whilst prophylactic antibiotic therapy and muco-ciliary clearance are additional treatment options. This review examines the diagnosis and management of respiratory issues in children with CVID.

Bloodstream infections after solid-organ transplantation

Solid-organ transplantation (SOT) has become the preferred strategy to treat a number of end-stage organ disease, because a continuous improvement in survival and quality of life. While preventive strategies has decreased the risk for classical opportunistic infections (such as viral, fungal and parasite infections), bacterial infections, and particularly bloodstream infections (BSIs) remain the most common and life-threatening complications in SOT recipients. The source of BSI after transplant depends on the type of transplantation, being urinary tract infection, pneumonia, and intraabdominal infections the most common infections occurring after kidney, lung and liver transplantation, respectively. The risk for candidemia is higher in abdominal-organ than in thoracic-organ transplantation. Currently, the increasing prevalence of multi-drug resistant (MDR) Gram-negative pathogens, such as extended-spectrum betalactamase-producing Enterobacteriaciae and carbapenem-resistant Klebsiella pneumoniae, is causing particular concerns in SOT recipients, a population which presents several risk factors for developing infections due to MDR organisms. The application of strict preventive policies to reduce the incidence of post transplant BSIs and to control the spread of MDR organisms, including the implementation of specific stewardship programs to avoid the overuse of antibiotics and antifungal drugs, are essential steps to reduce the impact of post transplant infections on allograft and patient outcomes.

Value of allohaemagglutinins in the diagnosis of a polysaccharide antibody deficiency

Polysaccharide antibody deficiency is characterized by a poor or absent antibody response after vaccination with an unconjugated pneumococcal polysaccharide vaccine. Allohaemagglutinins (AHA) are antibodies to A or B polysaccharide antigens on the red blood cells, and are often used as an additional or alternative measure to assess the polysaccharide antibody response. However, few studies have been conducted to establish the clinical significance of AHA. To investigate the value of AHA to diagnose a polysaccharide antibody deficiency, pneumococcal polysaccharide antibody titres and AHA were studied retrospectively in 180 subjects in whom both tests had been performed. Receiver operating characteristic curves for AHA versus the pneumococcal vaccine response as a marker for the anti-polysaccharide immune response revealed an area under the curve between 0·5 and 0·573. Sensitivity and specificity of AHA to detect a polysaccharide antibody deficiency, as diagnosed by vaccination response, were low (calculated for cut-off 1/4-1/32). In subjects with only low pneumococcal antibody response, the prevalence of bronchiectasis was significantly higher than in subjects with only low AHA (45·5 and 1·3%, respectively) or normal pneumococcal antibody response and AHA (2·4%). A logistic regression model showed that low pneumococcal antibody response but not AHA was associated with bronchiectasis (odds ratio 46·2). The results of this study do not support the routine use of AHA to assess the polysaccharide antibody response in patients with suspected immunodeficiency, but more studies are warranted to clarify the subject further.

Common variable immunodeficiency disorder - An uncommon cause for bronchiectasis

Bronchiectasis continues to be a common respiratory problem of varied etiology. Common variable immunodeficiency disorder (CVID) is an uncommon cause for bronchiectasis. However, the prevalence of bronchiectasis remains very high in patients with CVID. This remains largely an underdiagnosed entity as primary immunodeficiency is not suspected in adults as a cause of bronchiectasis and hence, serum immunoglobulin (Ig) levels are not measured routinely. In addition to bronchiectasis, patients with CVID usually present with various extrapulmonary symptoms. I report here a case of young man who presented with bronchiectasis and multisystem complains who was diagnosed as CVID.

Genomic Investigations unmask Mycoplasma amphoriforme, a new respiratory pathogen

The results of high-resolution whole-genome sequencing data provide compelling evidence that Mycoplasma amphoriforme produces chronic relapsing infection and, importantly, is transmitted in a hospital environment.

Background. Mycoplasma amphoriforme has been associated with infection in patients with primary antibody deficiency (PAD). Little is known about the natural history of infection with this organism and its ability to be transmitted in the community.

Methods. The bacterial load was estimated in sequential sputum samples from 9 patients by quantitative polymerase chain reaction. The genomes of all available isolates, originating from patients in the United Kingdom, France, and Tunisia, were sequenced along with the type strain. Genomic data were assembled and annotated, and a high-resolution phylogenetic tree was constructed.

Results. By using high-resolution whole-genome sequencing (WGS) data, we show that patients can be chronically infected with M. amphoriforme manifesting as a relapsing-remitting bacterial load, interspersed by periods when the organism is undetectable. Importantly, we demonstrate transmission of strains within a clinical environment. Antibiotic resistance mutations accumulate in isolates taken from patients who received multiple courses of antibiotics.

Conclusions. Mycoplasma amphoriforme isolates form a closely related species responsible for a chronic relapsing and remitting infection in PAD patients in the United Kingdom and from immunocompetent patients in other countries. We provide strong evidence of transmission between patients attending the same clinic, suggesting that screening and isolation may be necessary for susceptible patients. This work demonstrates the critical role that WGS can play in rapidly unraveling the biology of a novel pathogen.

IgE deficiency may indicate underlying hypogammaglobulinaemia?

Low serum immunoglobulin E (IgE) (<2 kU/L) found during allergy investigations may be a marker for other immunodeficiency states, in particular common variable immunodeficiency. The latter is characterised by recurrent infections, mainly respiratory, resulting in structural lung damage making early diagnosis important. We looked through 4013 samples retrospectively over a 12-month period to identify samples with IgE <2 kU/L. We identified 74/4013 (1.84%) with serum IgE levels <2 kU/L. Only 20 samples had serum immunoglobulin quantification and serum electrophoresis requested. Three of these samples were from the same patient, 10/18 (56%) had one or more classes of immunoglobulin above/below reference range for age and two of these had new diagnosis of immunodeficiency. Serum IgE <2 kU/L can be a marker for hypogammaglobulinaemia or common variable immunodeficiency. As early diagnosis is important to reduce morbidity and mortality, very low serum IgE should trigger further investigation—that is, serum protein electrophoresis and immunoglobulin quantification.

Secondary antibody deficiency

Secondary antibody deficiencies are defined by a quantitative or qualitative decrease in antibodies that occur most commonly as a consequence of renal or gastrointestinal immunoglobulin loss, hematological malignancies and corticosteroid, immunosuppressive or anticonvulsant medications. Patients with hematological malignancies or requiring immunosuppressive medications are known to be at increased risk of infection, but few studies directly address this relationship in the context of antibody deficiency. Immunoglobulin replacement therapy has been shown to be effective in reducing infections in primary and some secondary antibody deficiencies. The commonly encountered causes of secondary antibody deficiencies and their association with infection-related morbidity and mortality are discussed. Recommendations are made for screening and clinical management of those at risk.

Common variable immunodeficiency-associated granulomatous and interstitial lung disease

PURPOSE OF REVIEW

Common variable immunodeficiency (CVID) is the most common primary immunodeficiency characterized by a deficiency of immunoglobulins. Approximately 30% of the patients develop autoimmune and granulomatous disease. Similar to sarcoidosis, granulomatous disease in CVID can potentially affect all organs, but the lung is the most common. Interstitial lung disease (ILD) manifests in 5-15% of CVID patients, and is present already at the initial diagnosis in the majority of patients. The number of published studies addressing ILD in CVID is limited. However, recently, several studies added substantial knowledge to the field and are discussed within this review in the context of the literature.

RECENT FINDINGS

Histologically, ILD in CVID presents within the known patterns of sarcoid-like granuloma, organizing pneumonia, lymphocytic interstitial pneumonitis and nonspecific interstitial pneumonia. Often, these patterns are concomitantly found in the same patients. Three new articles were published which analyzed high-resolution computed tomography findings and response to treatment.

SUMMARY

In a considerable number of patients, ILD is stable over years and patients may not need any immunosuppressive treatment. Prednisone treatment is often used as the first-line treatment and studies suggest response to treatment in 50-66% of cases. In progressive disease with lung function impairment, combined immunosuppressive treatment is recommended.

Pulmonary manifestations of primary immunodeficiency disorders in children

Primary immunodeficiencies (PIDs) are inherited disorders in which one or several components of immune system are decreased, missing, or of non-appropriate function. These diseases affect the development, function, or morphology of the immune system. The group of PID comprises more than 200 different disorders and syndromes and the number of newly recognized and revealed deficiencies is still increasing. Their clinical presentation and complications depend on the type of defects and there is a great variability in the relationship between genotypes and phenotypes. A variation of clinical presentation across various age categories is also presented and children could widely differ from adult patients with PID. Respiratory symptoms and complications present a significant cause of morbidity and also mortality among patients suffering from different forms of PIDs and they are observed both in children and adults. They can affect primarily either upper airways (e.g., sinusitis and otitis media) or lower respiratory tract [e.g., pneumonia, bronchitis, bronchiectasis, and interstitial lung diseases (ILDs)]. The complications from lower respiratory tract are usually considered to be more important and also more specific for PIDs and they determinate patients' prognosis. The spectrum of the causal pathogens usually demonstrates typical pattern characteristic for each PID category. The respiratory signs of PIDs can be divided into infectious (upper and lower respiratory tract infections and complications) and non-infectious (ILDs, bronchial abnormalities - especially bronchiectasis, malignancies, and benign lymphoproliferation). Early diagnosis and appropriate therapy can prevent or at least slow down the development and course of respiratory complications of PIDs.

What is the impact of hypogammaglobulinemia on the rate of infections and survival in solid organ transplantation? A meta-analysis

Hypogammaglobulinemia has been described after solid organ transplantation and has been associated with increased risk of infections. The aim of the study was to evaluate the rate of severe hypogammaglobulinemia and its relationship with the risk of infections during the first year posttransplantation. Eighteen studies (1756 patients) that evaluated hypogammaglobulinemia and posttransplant infections were included. The data were pooled using the DerSimonian and Laird random-effects model. Q statistic method was used to assess statistical heterogeneity. Within the first year posttransplantation, the rate of hypogammaglobulinemia (IgG < 700 mg/dL) was 45% (95% CI: 0.34-0.55; Q = 330.1, p < 0.0001), the rate of mild hypogammaglobulinemia (IgG = 400-700 mg/dL) was 39% (95% CI: 0.22-0.56; Q = 210.09, p < 0.0001) and the rate of severe hypogammaglobulinemia (IgG < 400 mg/dL) was 15% (95% CI: 0.08-0.22; Q = 50.15, p < 0.0001). The rate of hypogammaglobulinemia by allograft type: heart 49% (21%-78%; Q = 131.16, p < 0.0001); kidney 40% (30%-49%; Q = 24.55, p = 0.0002); liver 16% (0.001%-35%; Q = 14.31, p = 0.0002) and lung 63% (53%-74%; Q = 6.85, p = 0.08). The odds of respiratory infection (OR = 4.83; 95% CI: 1.66-14.05; p = 0.004; I(2) = 0%), CMV (OR = 2.40; 95% CI: 1.16-4.96; p = 0.02; I(2) = 26.66%), Aspergillus (OR = 8.19; 95% CI: 2.38-28.21; p = 0.0009; I(2) = 17.02%) and other fungal infections (OR = 3.69; 95% CI: 1.11-12.33; p = 0.03; I(2) = 0%) for patients with IgG < 400 mg/dL were higher than the odds for patients with IgG > 400 mg/dL. The odds for 1-year all-cause mortality for severe hypogammaglobulinemia group was 21.91 times higher than those for IgG > 400 mg/dL group (95% CI: 2.49-192.55; p = 0.005; I(2) = 0%). Severe hypogammaglobulinemia during the first year posttransplantation significantly increased the risk of CMV, fungal and respiratory infections, and was associated with higher 1-year all-cause mortality.

Bringing immunoglobulin knowledge up to date: how should we treat today?

Immunoglobulin (Ig) therapy is constantly evolving. Advances in the basic and clinical science of immunoglobulins have provided new perspectives in using polyclonal IgG to treat patients with primary immunodeficiencies. Recent meta-analyses of patient data and outcomes, optimization of IgG administration and better understanding of the IgG receptor variability and clinical effect are new concepts which practising immunologists can use in tailoring their approach to treating patients with primary immunodeficiencies. This manuscript presents the proceedings of a satellite symposium, held in conjunction with the European Society for Immunodeficiencies (ESID) 2010 meeting, to inform attendees about new scientific concepts in IgG therapy, with the goal of empowering expert level evaluation of what optimal IgG therapy is today.

Detection of pulmonary complications in common variable immunodeficiency

Touw CML, van de Ven AA, de Jong PA, Terheggen-Lagro S, Beek E, Sanders EAM, van Montfrans JM. Detection of pulmonary complications in common variable immunodeficiency. Pediatr Allergy Immunol 2010: 21: 793-805. (c) 2009 John Wiley & Sons A/S Pulmonary complications are frequently observed in common variable immunodeficiency (CVID). We reviewed the literature related to radiologic imaging techniques and pulmonary function tests (PFT) for diagnosing pulmonary complications in CVID. Scientific publications related to CVID (or primary hypogammaglobulinemia), pulmonary complications, PFT, chest X-ray (CXR), and high-resolution computed tomography scan (HRCT) were detected in PubMed, Embase and in reference lists of selected articles. Twenty-six articles including 1047 patients (587 patients with CVID) were reviewed. Up to 73% of CVID patients develop chronic structural pulmonary complications, of which bronchiectasis and bronchial wall thickening are most frequently detected. HRCT is the most sensitive method for identification of structural abnormalities, detecting pulmonary complications that were missed on CXR and PFT in 2-59% of patients. On PFT, obstructive flow-volume curves were most commonly found, eventually occurring in 50-94% of patients. HRCT is an important diagnostic tool for pulmonary complications in CVID at the time of diagnosis and at regular time-points during follow-up, with the proper follow-up interval yet to be determined.

Antimicrobial prophylaxis for primary immunodeficiencies

PURPOSE OF REVIEW

Antibiotic prophylaxis is one of the mainstays of therapy of primary immunodeficiencies. We aim to summarize what is known about antibiotic prophylaxis for select primary immunodeficiencies.

RECENT FINDINGS

In recent years, there has been a push towards more evidence-based practices for antimicrobial prophylaxis for many conditions such as antifungal prophylaxis for extremely premature neonates and antibiotic prophylaxis for neutropenia associated with chemotherapy. However, there are remarkably few data regarding antibiotic prophylaxis in primary immunodeficiencies and regimens vary greatly between practices.

SUMMARY

Currently, antibiotic prophylaxis is guided by the common microbial pathogens seen in specific immunodeficiencies, and experience with other chronic illnesses such as cystic fibrosis, HIV, and immunosuppression from transplantation. Controlled studies are necessary to address the preferred antimicrobial and immunomodulator regimens for most of the primary immunodeficiencies.

A CT scan score for the assessment of lung disease in children with common variable immunodeficiency disorders

BACKGROUND

The prevalence and severity of structural lung disease in children with common variable immunodeficiency (CVID) disorders is not well known, and a dedicated CT scanning protocol and CT scan scoring system have not been described in this category.

METHODS

This was a cohort study of 54 children (34 CVID, 20 CVID-like disorder) in a stable condition who underwent volumetric inspiratory and end-expiratory CT scans. Scans were scored for airway abnormalities, interstitial and parenchymal lung disease, and lymphadenopathy using a newly developed CT scan scoring system. Scores were normalized to a 0% to 100% scale. Observer agreement was assessed using an intraclass correlation coefficient (Ri). Prevalence and severity of CT scan abnormalities were calculated.

RESULTS

Structural lung disease was common (85%-93%), but usually mild as reflected in the relatively low scores (bronchiectasis score 2.8% +/- 6.4%). Moderate-to-severe bronchiectasis was found in three (5%) patients. Expiratory air trapping was the most common finding, found in 71% to 80%, but often in a mild form; application of a cut off level of > 10% reduced its prevalence to 33% to 38%. In 9% to 15% of all patients, air trapping was the only abnormality. Multiple lung nodules were seen in 24% to 25% and could disappear after corticosteroid treatment. Observer agreement was moderate (Ri 0.6-0.79) to good (Ri > 0.8) for all items and the composite scores, except airway wall thickening.

CONCLUSION

In children with CVID disorders, mild structural lung disease is common. Expiratory CT scans show the most frequent abnormality, air trapping. The occurrence of (silent) lung disease progression and the clinical impact of CT scans require further investigations.