Asymptomatic immunodeficiency-associated vaccine-derived poliovirus infections in two UK children

Increasing detections of vaccine-derived poliovirus (VDPV) globally, including in countries previously declared polio free, is a public health emergency of international concern. Individuals with primary immunodeficiency (PID) can excrete polioviruses for prolonged periods, which could act as a source of cryptic transmission of viruses with potential to cause neurological disease. Here, we report on the detection of immunodeficiency-associated VDPVs (iVDPV) from two asymptomatic male PID children in the UK in 2019. The first child cleared poliovirus with increased doses of intravenous immunoglobulin, the second child following haematopoetic stem cell transplantation. We perform genetic and phenotypic characterisation of the infecting strains, demonstrating intra-host evolution and a neurovirulent phenotype in transgenic mice. Our findings highlight a pressing need to strengthen polio surveillance. Systematic collection of stool from asymptomatic PID patients who are at high risk for poliovirus excretion could improve the ability to detect and contain iVDPVs.

Haploidentical CD3+ TCR αβ/CD19+-depleted HSCT for MHC class II deficiency and persistent SARS-CoV-2 pneumonitis

Background

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection leads to coronavirus disease 2019 (COVID-19), which can range from a mild illness to a severe phenotype characterized by acute respiratory distress needing mechanical ventilation. Children with combined immunodeficiencies might be unable to mount a sufficient cellular and humoral immune response against COVID-19 and have persistent disease.

Objective

Our aim was to describe a child with combined immunodeficiency and a favorable post-hematopoietic stem cell transplant (HSCT) course following a haploidentical HSCT in the presence of persistent SARS-CoV-2 infection.

Methods

A 13-month-old girl with MHC class II deficiency developed persistent pre-HSCT SARS-CoV-2 infection. Faced with a significant challenge of balancing the risk of progressive infection due to an incompetent immune system with the danger of inflammatory pneumonitis peri-immune reconstitution after HSCT, the patient's physicians performed a maternal (with a recent history of COVID-19 infection) haploidentical HSCT. The patient received regdanvimab (after stem cell infusion) and remdesivir (before and after stem cell infusion).

Results

The patient exhibited a gradual increase in her cycle threshold values, implying a reduction in viral RNA with concomitant expansion in the CD3 lymphocyte subset and clinical and radiologic improvement.

Conclusions

Combination of adoptive transfer of maternal CD45RO⁺ memory addback T lymphocytes after haploidentical HSCT and use of regdanvimab (a SARS-CoV-2-neutralizing mAb) and remdesivir may have led to the successful outcome in our patient with severe immunodeficiency after she had undergone HSCT. This case highlights the role of novel antiviral strategies (mAbs and CD45RO⁺ memory T lymphocytes) in contributing to viral clearance in a challenging clinical scenario.

Characterising the allergic profile of children with cystic fibrosis

BACKGROUND

Cystic fibrosis (CF) is a genetic condition that affects multiple organ systems. Allergic bronchopulmonary aspergillosis (ABPA) is a well-recognised problem but other allergic conditions are less well documented in CF.

OBJECTIVE

To characterise the allergic profile of a cohort of children with CF, with a focus on those with ABPA.

METHODS

A cohort of children with CF were interviewed and retrospective data were collected regarding their allergic histories and other relevant clinical features.

RESULTS

The cohort included 37 children with median age of 9 years (interquartile range: 6-12). There was a history of ≥1 allergic condition(s) in 28/37 children (76%). The most common allergic condition was allergic rhinitis (AR) in 21/37 (57%) and 16 of these 21 children (76%) had another allergic condition. All children with ABPA (8) had another allergic condition. In some children ABPA exacerbations appeared to be seasonal, suggesting possible cross-sensitisation between Aspergillus fumigatus and aeroallergens associated with seasonal AR. Allergic conditions were also common in children with Pseudomonas aeruginosa infection.

The United Kingdom Primary Immune Deficiency (UKPID) registry 2012 to 2017

This is the second report of the United Kingdom Primary Immunodeficiency (UKPID) registry. The registry will be a decade old in 2018 and, as of August 2017, had recruited 4758 patients encompassing 97% of immunology centres within the United Kingdom. This represents a doubling of recruitment into the registry since we reported on 2229 patients included in our first report of 2013. Minimum PID prevalence in the United Kingdom is currently 5·90/100 000 and an average incidence of PID between 1980 and 2000 of 7·6 cases per 100 000 UK live births. Data are presented on the frequency of diseases recorded, disease prevalence, diagnostic delay and treatment modality, including haematopoietic stem cell transplantation (HSCT) and gene therapy. The registry provides valuable information to clinicians, researchers, service commissioners and industry alike on PID within the United Kingdom, which may not otherwise be available without the existence of a well-established registry.

Bronchiectasis and deteriorating lung function in agammaglobulinaemia despite immunoglobulin replacement therapy

Immunoglobulin replacement therapy enhances survival and reduces infection risk in patients with agammaglobulinaemia. We hypothesized that despite regular immunoglobulin therapy, some patients will experience ongoing respiratory infections and develop progressive bronchiectasis with deteriorating lung function. One hundred and thirty-nine (70%) of 199 patients aged 1-80 years from nine cities in the United Kingdom with agammaglobulinaemia currently listed on the UK Primary Immune Deficiency (UKPID) registry were recruited into this retrospective case study and their clinical and laboratory features analysed; 94% were male, 78% of whom had Bruton tyrosine kinase (BTK) gene mutations. All patients were on immunoglobulin replacement therapy and 52% had commenced therapy by the time they were 2 years old. Sixty per cent were also taking prophylactic oral antibiotics; 56% of patients had radiological evidence of bronchiectasis, which developed between the ages of 7 and 45 years. Multivariate analysis showed that three factors were associated significantly with bronchiectasis: reaching 18 years old [relative risk (RR) = 14·2, 95% confidence interval (CI) = 2·7-74·6], history of pneumonia (RR = 3·9, 95% CI = 1·1-13·8) and intravenous immunoglobulin (IVIG) rather than subcutaneous immunoglobulin (SCIG) = (RR = 3·5, 95% CI = 1·2-10·1), while starting immunoglobulin replacement after reaching 2 years of age, gender and recent serum IgG concentration were not associated significantly. Independent of age, patients with bronchiectasis had significantly poorer lung function [predicted forced expiratory volume in 1 s 74% (50-91)] than those without this complication [92% (84-101)] (P < 0·001). We conclude that despite immunoglobulin replacement therapy, many patients with agammaglobulinaemia can develop chronic lung disease and progressive impairment of lung function.