Homozygous NLRP1 gain-of-function mutation in siblings with a syndromic form of recurrent respiratory papillomatosis

© 2019 National Academy of Sciences. All rights reserved. Juvenile-onset recurrent respiratory papillomatosis (JRRP) is a rare and debilitating childhood disease that presents with recurrent growth of papillomas in the upper airway. Two common human papillomaviruses (HPVs), HPV-6 and -11, are implicated in most cases, but it is still not understood why only a small proportion of children develop JRRP following exposure to these common viruses. We report 2 siblings with a syndromic form of JRRP associated with mild dermatologic abnormalities. Whole-exome sequencing of the patients revealed a private homozygous mutation in NLRP1, encoding Nucleotide-Binding Domain Leucine-Rich Repeat Family Pyrin Domain-Containing 1. We find the NLRP1 mutant allele to be gain of function (GOF) for inflammasome activation, as demonstrated by the induction of inflammasome complex oligomerization and IL-1β secretion in an overexpression system. Moreover, patient-derived keratinocytes secrete elevated levels of IL-1β at baseline. Finally, both patients displayed elevated levels of inflammasome-induced cytokines in the serum. Six NLRP1 GOF mutations have previously been described to underlie 3 allelic Mendelian diseases with differing phenotypes and modes of inheritance. Our results demonstrate that an autosomal recessive, syndromic form of JRRP can be associated with an NLRP1 GOF mutation

Granulomatous-lymphocytic interstitial lung disease: an international research prioritisation

The first ever research prioritisation exercise in GLILD: this survey identified areas of interest in the diagnosis, treatment and management of GLILD, which can be used as a roadmap for future research

Granulomatous-lymphocytic interstitial lung disease: an international research prioritisation

The first ever research prioritisation exercise in GLILD: this survey identified areas of interest in the diagnosis, treatment and management of GLILD, which can be used as a roadmap for future research

Improved standardization of flow cytometry diagnostic screening of primary immunodeficiency by software-based automated gating

BackgroundMultiparameter flow cytometry (FC) is essential in the diagnostic work-up and classification of primary immunodeficiency (PIDs). The EuroFlow PID Orientation tube (PIDOT) allows identification of all main lymphocyte subpopulations in blood. To standardize data analysis, tools for Automated Gating and Identification (AG&I) of the informative cell populations, were developed by EuroFlow. Here, we evaluated the contribution of these innovative AG&I tools to the standardization of FC in the diagnostic work-up of PID, by comparing AG&I against expert-based (EuroFlow-standardized) Manual Gating (MG) strategy, and its impact on the reproducibility and clinical interpretation of results.MethodsFC data files from 44 patients (13 CVID, 12 PID, 19 non-PID) and 26 healthy donor (HD) blood samples stained with PIDOT were analyzed in parallel by MG and AG&I, using Infinicyt (TM) software (Cytognos). For comparison, percentage differences in absolute cell counts/mu L were calculated for each lymphocyte subpopulation. Data files showing differences >20% were checked for their potential clinical relevance, based on age-matched percentile (p5-p95) reference ranges. In parallel, intra- and inter-observer reproducibility of MG vs AG&I were evaluated in a subset of 12 samples.ResultsThe AG&I approach was able to identify the vast majority of lymphoid events (>99%), associated with a significantly higher intra- and inter-observer reproducibility compared to MG. For most HD (83%) and patient (68%) samples, a high degree of agreement (<20% numerical differences in absolute cell counts/mu L) was obtained between MG and the AG&I module. This translated into a minimal impact (<5% of observations) on the final clinical interpretation. In all except three samples, extended expert revision of the AG&I approach revealed no error. In the three remaining samples aberrant maturation and/or abnormal marker expression profiles were seen leading in all three cases to numerical alarms by AG&I.ConclusionAltogether, our results indicate that replacement of MG by the AG&I module would be associated with a greater reproducibility and robustness of results in the diagnostic work-up of patients suspected of PID. However, expert revision of the results of AG&I of PIDOT data still remains necessary in samples with numerical alterations and aberrant B- and T-cell maturation and/or marker expression profiles.Stemcel biology/Regenerative medicine (incl. bloodtransfusion

Screening protocols to monitor respiratory status in primary immunodeficiency disease: findings from a European survey and subclinical infection working group

Many patients with primary immunodeficiency (PID) who have antibody deficiency develop progressive lung disease due to underlying subclinical infection and inflammation. To understand how these patients are monitored we conducted a retrospective survey based on patient records of 13 PID centres across Europe, regarding the care of 1061 adult and 178 paediatric patients with PID on immunoglobulin (Ig) G replacement. The most common diagnosis was common variable immunodeficiency in adults (75%) and hypogammaglobulinaemia in children (39%). The frequency of clinic visits varied both within and between centres: every 1–12 months for adult patients and every 3–6 months for paediatric patients. Patients diagnosed with lung diseases were more likely to receive pharmaceutical therapies and received a wider range of therapies than patients without lung disease. Variation existed between centres in the frequency with which some clinical and laboratory monitoring tests are performed, including exercise tests, laboratory testing for IgG subclass levels and specific antibodies, and lung function tests such as spirometry. Some tests were carried out more frequently in adults than in children, probably due to difficulties conducting these tests in younger children. The percentage of patients seen regularly by a chest physician, or who had microbiology tests performed following chest and sinus exacerbations, also varied widely between centres. Our survey revealed a great deal of variation across Europe in how frequently patients with PID visit the clinic and how frequently some monitoring tests are carried out. These results highlight the urgent need for consensus guidelines on how to monitor lung complications in PID patients

EuroFlow Standardized Approach to Diagnostic Immunopheneotyping of Severe PID in Newborns and Young Children

The EuroFlow PID consortium developed a set of flow cytometry tests for evaluation of patients with suspicion of primary immunodeficiency (PID). In this technical report we evaluate the performance of the SCID-RTE tube that explores the presence of recent thymic emigrants (RTE) together with T-cell activation status and maturation stages and discuss its applicability in the context of the broader EuroFlow PID flow cytometry testing algorithm for diagnostic orientation of PID of the lymphoid system. We have analyzed peripheral blood cells of 26 patients diagnosed between birth and 2 years of age with a genetically defined primary immunodeficiency disorder: 1