Tuberculosis disease in immunocompromised children and adolescents: a pTBnet multi-centre case-control study.

BACKGROUND: In high-resource settings the survival of immunocompromised (IC) children has increased and immunosuppressive therapies are increasingly being used. This study aimed to determine the clinical characteristics, performance of diagnostic tools and outcome of IC children with TB in Europe. METHODS: Multicentre, matched case-control study within the Paediatric Tuberculosis Network European Trials Group (ptbnet), capturing TB cases <18 years diagnosed 2000-2020. RESULTS: 417 TB cases were included, comprising 139 children with IC (HIV, inborn errors of immunity, drug-induced immunosuppression and other immunocompromising conditions) and 278 non-IC children as controls. Non-respiratory TB was more frequent among cases than controls (32.4% vs. 21.2%; p = 0.013). IC patients had an increased likelihood of presenting with severe disease (57.6% vs. 38.5%; p < 0.001; OR [95% CI]: 2.073 [1.37-3.13]). Children with IC had higher rates of false-negative tuberculin skin test (31.9% vs. 6.0%; p < 0.001) and QuantiFERON-TB Gold assay (30.0% vs. 7.3%; p < 0.001) results at diagnosis. Overall, the microbiological confirmation rate was similar in IC and non-IC cases (58.3% vs. 49.3%; p = 0.083). Although the mortality in IC children was <1%, the rate of long-term sequelae was significantly higher than in non-IC cases (14.8% vs. 6.1%; p = 0.004). CONCLUSIONS: IC children with TB disease in Europe have increased rates of non-respiratory TB, severe disease, and long-term sequelae. Immune-based TB tests have poor sensitivity in those children. Future research should focus on developing improved immunological TB tests that perform better in IC patients, and determining the reasons for the increased risk of long-term sequelae, with the aim to design preventive management strategies.

A structured patient empowerment programme for primary immunodeficiency significantly improves general and health-related quality of life.

INTRODUCTION: Primary immunodeficiencies (PIDs) are a heterogeneous group of rare diseases characterized by increased susceptibility to infections and a reduced quality of life (QoL). The influence of a patient empowerment programme for PID (PID-PEP) on general and health-related QoL was assessed in the present study. MATERIAL AND METHODS: PID-PEP is provided by a multidisciplinary team for patients with PID and immunoglobulin G (IgG) replacement therapy during a weekend course to improve patient self-management regarding chronic disease and long-term therapy. Twenty-six adult patients with PID undergoing PID-PEP were recruited. Short Form-36 (SF-36) and the Life Quality Index (LQI) were assessed as generic and disease-specific QoL instruments before as well as 6 months after the programme. RESULTS: Median visual analogue scale (VAS) values of present health status significantly increased from 68 at baseline to 76 after PID-PEP (p = 0.002). Furthermore, the SF-36 mental component summary (MCS) significantly improved from 36 to 43 following the programme (p = 0.042). Of the eight SF-36 dimensions, vitality (VT) significantly improved (p = 0.025). Median LQI index significantly increased from 77 at baseline to 86 after PID-PEP (p = 0.008). Furthermore, the LQI domains treatment interference (I) and therapy-related problems (II) significantly improved. CONCLUSIONS: Our PID-PEP significantly improved general and health-related QoL. It needs to be evaluated in future studies whether the beneficial effects of PID-PEP are sustained over longer periods of time and whether repeated PID-PEP sessions further improve QoL outcome.

Simple Measurement of IgA Predicts Immunity and Mortality in Ataxia-Telangiectasia.

Patients with ataxia-telangiectasia (A-T) suffer from progressive cerebellar ataxia, immunodeficiency, respiratory failure, and cancer susceptibility. From a clinical point of view, A-T patients with IgA deficiency show more symptoms and may have a poorer prognosis. In this study, we analyzed mortality and immunity data of 659 A-T patients with regard to IgA deficiency collected from the European Society for Immunodeficiencies (ESID) registry and from 66 patients with classical A-T who attended at the Frankfurt Goethe-University between 2012 and 2018. We studied peripheral B- and T-cell subsets and T-cell repertoire of the Frankfurt cohort and survival rates of all A-T patients in the ESID registry. Patients with A-T have significant alterations in their lymphocyte phenotypes. All subsets (CD3, CD4, CD8, CD19, CD4/CD45RA, and CD8/CD45RA) were significantly diminished compared to standard values. Patients with IgA deficiency (n = 35) had significantly lower lymphocyte counts compared to A-T patients without IgA deficiency (n = 31) due to a further decrease of naïve CD4 T-cells, central memory CD4 cells, and regulatory T-cells. Although both patient groups showed affected TCR-ß repertoires compared to controls, no differences could be detected between patients with and without IgA deficiency. Overall survival of patients with IgA deficiency was significantly diminished. For the first time, our data show that patients with IgA deficiency have significantly lower lymphocyte counts and subsets, which are accompanied with reduced survival, compared to A-T patients without IgA deficiency. IgA, a simple surrogate marker, is indicating the poorest prognosis for classical A-T patients. Both non-interventional clinical trials were registered at clinicaltrials.gov 2012 (Susceptibility to infections in ataxia-telangiectasia; NCT02345135) and 2017 (Susceptibility to Infections, tumor risk and liver disease in patients with ataxia-telangiectasia; NCT03357978).

Innate IgG molecules and innate B cells expressed by immunoglobulin constant heavy G chain (Fcγ) genetic marker genes are involved in the 'allergic march' of IgE sensitization in children.

BACKGROUND: Interindividual variations of immunoglobulin constant heavy G chain (IGHG) genes on chromosome 14q32.3 are identified by alternative genetic markers (GM) of IgG3, IgG1 and IgG2, respectively. They express structurally and functionally innate IgG molecules and B cells, associated with allergic disease, replicated in several studies. MATERIALS AND METHODS: 1-year-old and 10-year-old, IgE-sensitized and non-sensitized children from the German Multicenter Allergy Study birth cohort were assessed by new serological methods for the mendelian IGHG (Fcγ) (GM) genes, as innate IgG molecules and innate B cells. RESULTS: Food allergy sensitization in thirty-five 1-year-old children (124 not sensitized) was associated with the IGHG*bfn haplotype and B*(bfn) cells (OR 1.9, 95% CI 1.2-3.1; p = 0.010). Aeroallergen sensitization in ninety-nine 10-year-old children (95 not sensitized) was associated with the same genes (OR 1.4, 95% CI 1.02-1.9; p = 0.034). The IgE sensitization was most prominent in the restrictive homozygous IGHG*bfn/*bfn diplotype, 34% at age 1, increasing to 60% at age 10, rating the highest numbers of positive IgE tests, expressing increased levels of IgE and innate IgG2*n. CONCLUSIONS: The IGHG*bfn haplotype (B*(bfn) cells) and increased innate IgG2*n levels are predictive factors for IgE sensitization in childhood. IGHG genes can be assessed for prognostic and preventive purposes in clinical care.