Lung clearance index predicts pulmonary exacerbations in individuals with primary ciliary dyskinesia: a multicentre cohort study

BACKGROUND

Lung clearance index (LCI) is a promising lung function outcome in individuals with primary ciliary dyskinesia (PCD). The impact of events clinically important for individuals with PCD, such as pulmonary exacerbations, on LCI is unknown.

METHODS

We conducted an international, multicentre, observational cohort study to assess the association of LCI and risk of pulmonary exacerbation, specific changes in LCI during pulmonary exacerbation and global variability of LCI across four visits every 4 months. Ninety individuals with PCD, aged 3-41 years, underwent nitrogen multiple-breath washout (MBW) and spirometry measurements. The association of LCI and pulmonary exacerbations was assessed by Cox proportional hazards and random-effects regression models.

RESULTS

We obtained 430 MBW and 427 spirometry measurements. In total, 379 person-years at risk contributed to the analysis. Per one unit increase (deterioration) in LCI, the risk of future pulmonary exacerbation increased by 13%: HR (95% CI), 1.13 (1.04 to 1.23). If LCI changed from a range of values considered normal to abnormal, the risk of future pulmonary exacerbations increased by 87%: 1.87 (1.08 to 3.23). During pulmonary exacerbations, LCI increased by 1.22 units (14.5%). After pulmonary exacerbations, LCI tended to decline. Estimates of variability in LCI suggested lower variation within individuals compared with variation between individuals. Findings were comparable for forced expiratory volume in 1 s.

CONCLUSION

On a visit-to-visit basis, LCI measurement may add to the prediction of pulmonary exacerbations, the assessment of lung function decline and the potential lung function response to treatment of pulmonary exacerbations.

Coronavirus disease 2019 in patients with inborn errors of immunity: An international study

BACKGROUND

There is uncertainty about the impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in individuals with rare inborn errors of immunity (IEI), a population at risk of developing severe coronavirus disease 2019. This is relevant not only for these patients but also for the general population, because studies of IEIs can unveil key requirements for host defense.

OBJECTIVE

We sought to describe the presentation, manifestations, and outcome of SARS-CoV-2 infection in IEI to inform physicians and enhance understanding of host defense against SARS-CoV-2.

METHODS

An invitation to participate in a retrospective study was distributed globally to scientific, medical, and patient societies involved in the care and advocacy for patients with IEI.

RESULTS

We gathered information on 94 patients with IEI with SARS-CoV-2 infection. Their median age was 25 to 34 years. Fifty-three patients (56%) suffered from primary antibody deficiency, 9 (9.6%) had immune dysregulation syndrome, 6 (6.4%) a phagocyte defect, 7 (7.4%) an autoinflammatory disorder, 14 (15%) a combined immunodeficiency, 3 (3%) an innate immune defect, and 2 (2%) bone marrow failure. Ten were asymptomatic, 25 were treated as outpatients, 28 required admission without intensive care or ventilation, 13 required noninvasive ventilation or oxygen administration, 18 were admitted to intensive care units, 12 required invasive ventilation, and 3 required extracorporeal membrane oxygenation. Nine patients (7 adults and 2 children) died.

CONCLUSIONS

This study demonstrates that (1) more than 30% of patients with IEI had mild coronavirus disease 2019 (COVID-19) and (2) risk factors predisposing to severe disease/mortality in the general population also seemed to affect patients with IEI, including more younger patients. Further studies will identify pathways that are associated with increased risk of severe disease and are nonredundant or redundant for protection against SARS-CoV-2.

How to approach complications of acute rhinosinusitis in children?

Intraorbital and intracranial complications of acute rhinosinusitis (ARS) are uncommon, but potentially life threatening. Signs of progression of ARS should be recognized early to allow timely surgical treatment in order to avoid irreversible lesions such as vision loss and neurological deficits. In this case series, we provide an overview of 6 representative cases who presented at our tertiary center (2017-2018). The aim of this case series is (1) to draw new attention to the clinical manifestations and management of these complications, since even in highly-developed medical settings we still observe permanent sequellae due to delayed or inadequate treatment, (2) to give an updated analysis of the guidelines, stressing the low threshold for endoscopic sinus surgery, even in children, (3) to underline the benefits of a multidisciplinary approach in these young patients.

Fast compressive lens-free tomography for 3D biological cell culture imaging

We present a compressive lens-free technique that performs tomographic imaging across a cubic millimeter-scale volume from highly sparse data. Compared with existing lens-free 3D microscopy systems, our method requires an order of magnitude fewer multi-angle illuminations for tomographic reconstruction, leading to a compact, cost-effective and scanning-free setup with a reduced data acquisition time to enable high-throughput 3D imaging of dynamic biological processes. We apply a fast proximal gradient algorithm with composite regularization to address the ill-posed tomographic inverse problem. Using simulated data, we show that the proposed method can achieve a reconstruction speed ∼10× faster than the state-of-the-art inverse problem approach in 3D lens-free microscopy. We experimentally validate the effectiveness of our method by imaging a resolution test chart and polystyrene beads, demonstrating its capability to resolve micron-size features in both lateral and axial directions. Furthermore, tomographic reconstruction results of neuronspheres and intestinal organoids reveal the potential of this 3D imaging technique for high-resolution and high-throughput biological applications.

Chest CT scoring for evaluation of lung sequelae in congenital diaphragmatic hernia survivors

OBJECTIVES

Data on long-term structural lung abnormalities in survivors of congenital diaphragmatic hernia (CDH) is scarce. The purpose of this study was to develop a chest computed tomography (CT) score to assess the structural lung sequelae in CDH survivors and to study the correlation between the CT scoring and clinical parameters in the neonatal period and at 1 year of follow-up.

METHODS

A prospective, clinical follow-up program is organised for CDH survivors at the University Hospital of Leuven including a chest CT at the age of 1 year. The CT scoring used and evaluated, named CDH-CT score, was adapted from the revised Aukland score for chronic lung disease of prematurity.

RESULTS

Thirty-five patients were included. All CT scans showed some pulmonary abnormalities, ranging from very mild to severe. The mean total CT score was 16 (IQR: 9-23), with the greatest contribution from the subscores for decreased attenuation (5; IQR: 2-8), subpleural linear and triangular opacities (4; IQR: 3-5), and atelectasis/consolidation (2; IQR: 1-3). Interobserver and intraobserver agreement was very good for the total score (ICC coefficient > 0.9). Total CT score correlated with number of neonatal days ventilated/on oxygen as well as with respiratory symptoms and feeding problems at 1 year of age.

CONCLUSION

The CDH-CT scoring tool has a good intraobserver and interobserver repeatability and correlates with relevant clinical parameters. This holds promise for its use in clinical follow-up and as outcome parameter in clinical interventional studies.

Lung function evolution in children with old and new type bronchopulmonary dysplasia: a retrospective cohort analysis

Bronchopulmonary dysplasia (BPD) is one of the most important sequelae of premature birth. There is concern that in some patients, lung injuries early in life may have lifelong consequences. In this retrospective observational cohort study, lung function evolution in children with BPD was investigated from childhood to young adulthood. Data from 355 pulmonary function tests (PFT) in 24 patients were analyzed, with a median age at first PFT of 7.6 years and at last PFT 18.2 years. FEV₁ and FEV₁/FVC were below the 5th percentile in respectively 18 and 13/24 patients. Comparing first and last measurement, there was significant worsening in FEV₁ from a mean of 71.3% pred (SD 18.3) to 66.7% pred (SD 21.7) (p < 0.05) and in FEV₁/FVC from 85.4% pred (SD 15.2) to 79.8% pred (SD 17.3) (p = 0.01). Evaluation of the individual lung function changes with linear regression showed deterioration in FEV₁, FVC, and FEV₁/FVC in respectively 17, 13, and 17/24 patients. Total group analysis showed significant deterioration in FEV₁ (- 0.7%/year, p = 0.002) and FEV₁/FVC (- 0.5%/year, p = 0.01). None of the 11 patients born up to 1990 improved in FEV₁ vs 7 of the 13 patients born after 1990 (p = 0.006).Conclusion: This points out to further deterioration of the lung function during childhood in this selected group of children with BPD.What is Known:• Data on longitudinal changes in lung function in children with BPD are scarce.What is New:• In children with BPD at the severe end of the disease spectrum, lung function does not improve over time. On the contrary, in two-thirds of the subjects studied FEV₁and FEV₁/FVC worsen over time.• Lung function evolution towards adulthood was somewhat more favorable in children born after 1990 compared with those born earlier, probably reflecting improvements in neonatal care in subjects with new type BPD.

The long-term outcome of an isolated vascular ring - A single-center experience

BACKGROUND AND OBJECTIVES

The aim of this study is to document the long-term outcome of patients with a vascular ring.

METHODS

A single-center retrospective review of clinical symptoms was conducted in all patients born between 1980 and 2013, diagnosed with a complete vascular ring and at least 2 years of follow-up. Data were extracted from patient files and clinical symptoms were assessed by questionnaires sent to the parents. Age and diagnostic tools, type of surgery, postoperative complications, and the prevalence of clinical symptoms (stridor at rest, stridor with exercise, cough, exercise intolerance, dysphagia, and frequent respiratory infections) were reviewed.

RESULTS

Fifty-one patients were included. The diagnosis was made before the age of 2 in 35/51. Surgery was performed in 41/51 patients with a limited number of reversible complications. The median follow-up was 8 (IQR 5-12) years. After 2 years, 21/51 patients were asymptomatic: 2/7 asymptomatic patients at diagnosis became symptomatic and symptoms resolved in 16/44 initially symptomatic patients. Consequently, 30/51 patients still had symptoms after 2 years. Of these, 16 had partial improvement, 5 stable symptoms, and 9 aggravation of symptoms. After 10 years, 26/36 patients were free of complaints. The most frequent long-term symptom was stridor.

CONCLUSION

Surgical treatment of a congenital vascular ring is safe and mostly performed in patients with a double aortic arch. Conservative treatment for patients with little symptoms seems to be justifiable. A considerable number of patients have residual long-term symptoms after surgical relief of the vascular ring.

Defining Polysaccharide Antibody Deficiency: Measurement of Anti-Pneumococcal Antibodies and Anti-Salmonella typhi Antibodies in a Cohort of Patients with Recurrent Infections

BACKGROUND

The correlation between different methods for the detection of pneumococcal polysaccharide vaccine (PPV) responses to diagnose specific polysaccharide antibody deficiency (SAD) is poor and the criteria for defining a normal response lack consensus. We previously proposed fifth percentile (p5) values of PPV responses as a new cutoff for SAD.

OBJECTIVE

To analyze the association of SAD (determined by either World Health Organization (WHO)-standardized ELISA or multiplex bead-based assay) with abnormal response to Salmonella (S.) typhi Vi vaccination in a cohort of patients with recurrent infections.

METHODS

Ninety-four patients with a clinical history suggestive of antibody deficiency received PPV and S. typhi Vi vaccines. Polysaccharide responses to either 3 or 18 pneumococcal serotypes were measured by either the WHO ELISA or a multiplex in-house bead-based assay. Anti-S. typhi Vi IgG were measured by a commercial ELISA kit. Allohemagglutinins (AHA) were measured by agglutination method.

RESULTS

Based on the American Academy of Allergy, Asthma and Immunology (AAAAI) criteria for WHO ELISA, 18/94 patients were diagnosed with SAD and 22/93 based on serotype-specific p5 cutoffs for bead-based assay. The association between the two methods was significant, with 10 subjects showing abnormal response according to both techniques. Abnormal response to S. typhi Vi vaccination was found in 7 patients, 6 of which had SAD. No correlation was found between polysaccharide response and AHA, age, or clinical phenotype.

CONCLUSION

The lack of evidence-based gold standards for the diagnosis of SAD represents a challenge in clinical practice. In our cohort, we confirmed the insufficient correlation between different methods of specific PPV response measurement, and showed that the S. typhi Vi response was not contributive. Caution in the interpretation of results is warranted until more reliable diagnostic methods can be validated.

Elexacaftor-Tezacaftor-Ivacaftor for Cystic Fibrosis with a Single Phe508del Allele

BACKGROUND

Cystic fibrosis is caused by mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) protein, and nearly 90% of patients have at least one copy of the Phe508del CFTR mutation. In a phase 2 trial involving patients who were heterozygous for the Phe508del CFTR mutation and a minimal-function mutation (Phe508del-minimal function genotype), the next-generation CFTR corrector elexacaftor, in combination with tezacaftor and ivacaftor, improved Phe508del CFTR function and clinical outcomes.

METHODS

We conducted a phase 3, randomized, double-blind, placebo-controlled trial to confirm the efficacy and safety of elexacaftor-tezacaftor-ivacaftor in patients 12 years of age or older with cystic fibrosis with Phe508del-minimal function genotypes. Patients were randomly assigned to receive elexacaftor-tezacaftor-ivacaftor or placebo for 24 weeks. The primary end point was absolute change from baseline in percentage of predicted forced expiratory volume in 1 second (FEV₁) at week 4.

RESULTS

A total of 403 patients underwent randomization and received at least one dose of active treatment or placebo. Elexacaftor-tezacaftor-ivacaftor, relative to placebo, resulted in a percentage of predicted FEV₁ that was 13.8 points higher at 4 weeks and 14.3 points higher through 24 weeks, a rate of pulmonary exacerbations that was 63% lower, a respiratory domain score on the Cystic Fibrosis Questionnaire-Revised (range, 0 to 100, with higher scores indicating a higher patient-reported quality of life with regard to respiratory symptoms; minimum clinically important difference, 4 points) that was 20.2 points higher, and a sweat chloride concentration that was 41.8 mmol per liter lower (P<0.001 for all comparisons). Elexacaftor-tezacaftor-ivacaftor was generally safe and had an acceptable side-effect profile. Most patients had adverse events that were mild or moderate. Adverse events leading to discontinuation of the trial regimen occurred in 1% of the patients in the elexacaftor-tezacaftor-ivacaftor group.

CONCLUSIONS

Elexacaftor-tezacaftor-ivacaftor was efficacious in patients with cystic fibrosis with Phe508del-minimal function genotypes, in whom previous CFTR modulator regimens were ineffective. (Funded by Vertex Pharmaceuticals; VX17-445-102 ClinicalTrials.gov number, NCT03525444.).

Human DOCK2 Deficiency: Report of a Novel Mutation and Evidence for Neutrophil Dysfunction

DOCK2 is a guanine-nucleotide-exchange factor for Rac proteins. Activated Rac serves various cellular functions including the reorganization of the actin cytoskeleton in lymphocytes and neutrophils and production of reactive oxygen species in neutrophils. Since 2015, six unrelated patients with combined immunodeficiency and early-onset severe viral infections caused by bi-allelic loss-of-function mutations in DOCK2 have been described. Until now, the function of phagocytes, specifically neutrophils, has not been assessed in human DOCK2 deficiency. Here, we describe a new kindred with four affected siblings harboring a homozygous splice-site mutation (c.2704-2 A > C) in DOCK2. The mutation results in alternative splicing and a complete loss of DOCK2 protein expression. The patients presented with leaky severe combined immunodeficiency or Omenn syndrome. The novel mutation affects EBV-B cell migration and results in NK cell dysfunction similar to previous observations. Moreover, both cytoskeletal rearrangement and reactive oxygen species production are partially impaired in DOCK2-deficient neutrophils.