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Front Immunol. 2021 Feb 17;12:632997. doi: 10.3389/fimmu.2021.632997. eCollection 2021.

ABSTRACT

STAT1 gain-of-function (GOF) is a primary immunodeficiency typically characterized by chronic mucocutaneous candidiasis (CMC), recurrent respiratory infections, and autoimmunity. Less commonly, also immunodysregulation polyendocrinopathy enteropathy X-linked (IPEX)-like syndromes with CMC, and combined immunodeficiency without CMC have been described. Recently, our group and others have shown that different mutation-specific mechanisms underlie STAT1 GOF in vitro, including faster nuclear accumulation (R274W), and reduced mobility (R321, N574I) to near immobility in the nucleus (T419R) upon IFNγ stimulation. In this work, we evaluated the transcriptomic fingerprint of the aforementioned STAT1 GOF mutants (R274W, R321S, T419R, and N574I) relative to STAT1 wild-type upon IFNγ stimulation in an otherwise isogenic cell model. The majority of genes up-regulated in wild-type STAT1 cells were significantly more up-regulated in cells expressing GOF mutants, except for T419R. In addition to the common interferon regulated genes (IRG), STAT1 GOF mutants up-regulated an additional set of genes, that were in part shared with other GOF mutants or mutation-specific. Overall, R274W and R321S transcriptomes clustered with STAT1 WT, while T419R and N574I had a more distinct fingerprint. We observed reduced frequency of canonical IFNγ activation site (GAS) sequences in promoters of genes up-regulated by all the STAT1 GOF mutants, suggesting loss of DNA binding specificity for the canonical GAS consensus. Interestingly, the T419R mutation, expected to directly increase the affinity for DNA, showed the most pronounced effects on the transcriptome. T419R STAT1 dysregulated more non-IRG than the other GOF mutants and fewer GAS or degenerate GAS promotor sequences could be found in the promoter regions of these genes. In conclusion, our work confirms hyperactivation of common sets of IFNγ-induced genes in STAT1 GOF with additional dysregulation of mutation-specific genes, in line with the earlier observed mutation-specific mechanisms. Binding to more degenerate GAS sequences is proposed as a mechanism toward transcriptional dysregulation in R274W, R321S, and N574I. For T419R, an increased interaction with the DNA is suggested to result in a broader and less GAS-specific response. Our work indicates that multiple routes leading to STAT1 GOF are associated with common and private transcriptomic fingerprints, which may contribute to the phenotypic variation observed in vivo.

PMID:33679782 | PMC:PMC7925617 | DOI:10.3389/fimmu.2021.632997

Front Immunol. 2021 Feb 18;11:625753. doi: 10.3389/fimmu.2020.625753. eCollection 2020.

NO ABSTRACT

PMID:33679719 | PMC:PMC7935502 | DOI:10.3389/fimmu.2020.625753

Front Immunol. 2021 Feb 17;11:603972. doi: 10.3389/fimmu.2020.603972. eCollection 2020.

ABSTRACT

INTRODUCTION: Common Variable Immunodeficiency (CVID) is characterized by defective antibody production and hypogammaglobulinemia. Flow cytometry immunophenotyping of blood lymphocytes has become of great relevance for the diagnosis and classification of CVID, due to an impaired differentiation of mature post-germinal-center (GC) class-switched memory B-cells (MBC) and severely decreased plasmablast/plasma cell (Pb) counts. Here, we investigated in detail the pre-GC B-cell maturation compartment in blood of CVID patients.

METHODS: In this collaborative multicentric study the EuroFlow PID 8-color Pre-GC B-cell tube, standardized sample preparation procedures (SOPs) and innovative data analysis tools, were used to characterize the maturation profile of pre-GC B-cells in 100 CVID patients, vs 62 age-matched healthy donors (HD).

RESULTS: The Pre-GC B-cell tube allowed identification within pre-GC B-cells of three subsets of maturation associated immature B-cells and three subpopulations of mature naïve B-lymphocytes. CVID patients showed overall reduced median absolute counts (vs HD) of the two more advanced stages of maturation of both CD5⁺ CD38^+/++ CD21^het CD24⁺⁺ (2.7 vs 5.6 cells/µl, p=0.0004) and CD5⁺ CD38^het CD21⁺ CD24⁺ (6.5 vs 17 cells/µl, p<0.0001) immature B cells (below normal HD levels in 22% and 37% of CVID patients). This was associated with an expansion of CD21^–CD24^– (6.1 vs 0.74 cells/µl, p<0.0001) and CD21^–CD24⁺⁺ (1.8 vs 0.4 cells/µl, p<0.0001) naïve B-cell counts above normal values in 73% and 94% cases, respectively. Additionally, reduced IgMD⁺ (21 vs 32 cells/µl, p=0.03) and IgMD^– (4 vs 35 cells/µl, p<0.0001) MBC counts were found to be below normal values in 25% and 77% of CVID patients, respectively, always together with severely reduced/undetectable circulating blood pb. Comparison of the maturation pathway profile of pre-GC B cells in blood of CVID patients vs HD using EuroFlow software tools showed systematically altered patterns in CVID. These consisted of: i) a normally-appearing maturation pathway with altered levels of expression of >1 (CD38, CD5, CD19, CD21, CD24, and/or smIgM) phenotypic marker (57/88 patients; 65%) for a total of 3 distinct CVID patient profiles (group 1: 42/88 patients, 48%; group 2: 8/88, 9%; and group 3: 7/88, 8%) and ii) CVID patients with a clearly altered pre-GC B cell maturation pathway in blood (group 4: 31/88 cases, 35%).

CONCLUSION: Our results show that maturation of pre-GC B-cells in blood of CVID is systematically altered with up to four distinctly altered maturation profiles. Further studies, are necessary to better understand the impact of such alterations on the post-GC defects and the clinical heterogeneity of CVID.

PMID:33679693 | PMC:PMC7925888 | DOI:10.3389/fimmu.2020.603972

Pediatr Transplant. 2021 Mar 6:e13995. doi: 10.1111/petr.13995. Online ahead of print.

ABSTRACT

BACKGROUND: Unmanipulated haploid HSCT for SAA has resulted in improved outcomes over recent years. However, studies related to unmanipulated haploid HSCs combined with tp-UCB transplantation for other types of NMD are rare. Accordingly, we present the outcomes of 109 pediatric patients with life-threatening NMD undergoing unmanipulated haploid HSCs combined with tp-UCB transplantation.

PROCEDURE: We retrospectively investigated 109 pediatric patients with life-threatening NMD treated with unmanipulated haploid HSCs combined with tp-UCB transplantation in a single center.

RESULTS: The median days of neutrophil and platelet engraftment were +13 and +22 days, respectively. None of the cases experienced PGF. The incidence rates for grade I-II, III-IV aGVHD and cGVHD were 44.9%, 24.8%, and 9.3%, respectively. The incidence rates of CMV and EBV viremia were 46.7% and 39.4%, respectively. The median follow-up duration was 997 days. In total, 106 patients survived, including 104 cases with FFS and 2 cases with SGF. Three patients died. The 5-year TRM, OS, and FFS were 2.8%, 97.2%, and 96.2%, respectively.

CONCLUSION: The results of unmanipulated haploid HSCs combined with tp-UCB in pediatric patients with life-threatening NMD were promising. However, further research is now needed to determine specific factors that might influence the engraftment of HSCs.

PMID:33675566 | DOI:10.1111/petr.13995

J Pediatr Endocrinol Metab. 2020 Dec 16;34(3):277-294. doi: 10.1515/jpem-2020-0277. Print 2021 Mar 26.

ABSTRACT

Inborn errors of metabolism consist of a heterogeneous group of disorders with various organ systems manifestations, and some metabolic diseases also cause immunological disorders or dysregulation. In this review, metabolic diseases that affect the immunological system and particularly lead to primary immune deficiency will be reviewed. In a patient with frequent infections and immunodeficiency, the presence of symptoms such as growth retardation, abnormal facial appearance, heart, skeletal, lung deformities, skin findings, arthritis, motor developmental retardation, seizure, deafness, hepatomegaly, splenomegaly, impairment of liver function tests, the presence of anemia, thrombocytopenia and eosinophilia in hematological examinations should suggest metabolic diseases for the underlying cause. In some patients, these phenotypic findings may appear before the immunodeficiency picture. Metabolic diseases leading to immunological disorders are likely to be rare but probably underdiagnosed. Therefore, the presence of recurrent infections or autoimmune findings in a patient with a suspected metabolic disease should suggest that immune deficiency may also accompany the picture, and diagnostic examinations in this regard should be deepened.

PMID:33675210 | DOI:10.1515/jpem-2020-0277

Nat Commun. 2021 Mar 5;12(1):1467. doi: 10.1038/s41467-021-21627-0.

ABSTRACT

Efforts to contain the spread of SARS-CoV-2 have spurred the need for reliable, rapid, and cost-effective diagnostic methods which can be applied to large numbers of people. However, current standard protocols for the detection of viral nucleic acids while sensitive, require a high level of automation and sophisticated laboratory equipment to achieve throughputs that allow whole communities to be tested on a regular basis. Here we present Cap-iLAMP (capture and improved loop-mediated isothermal amplification) which combines a hybridization capture-based RNA extraction of gargle lavage samples with an improved colorimetric RT-LAMP assay and smartphone-based color scoring. Cap-iLAMP is compatible with point-of-care testing and enables the detection of SARS-CoV-2 positive samples in less than one hour. In contrast to direct addition of the sample to improved LAMP (iLAMP), Cap-iLAMP prevents false positives and allows single positive samples to be detected in pools of 25 negative samples, reducing the reagent cost per test to ~1 Euro per individual.

PMID:33674580 | DOI:10.1038/s41467-021-21627-0

PLoS One. 2021 Mar 4;16(3):e0247941. doi: 10.1371/journal.pone.0247941. eCollection 2021.

ABSTRACT

BACKGROUND: Common variable immunodeficiency disorders (CVID), the most common form of primary antibody deficiency, are rare conditions associated with considerable morbidity and mortality. The clinical benefit of immunoglobulin replacement therapy (IgGRT) is substantial: timely treatment with appropriate doses significantly reduces mortality and the incidence of CVID-complications such as major infections and bronchiectasis. Unfortunately, CVID-patients still face a median diagnostic delay of 4 years. Their disease burden, expressed in annual loss of disability-adjusted life years, is 3-fold higher than in the general population. Hurdles to treatment access and reimbursement by healthcare payers may exist because the value of IgGRT is poorly documented. This paper aims to demonstrate cost-effectiveness and cost-utility (on life expectancy and quality) of IgGRT in CVID.

METHODS AND FINDINGS: With input from a literature search, we built a health-economic model for cost-effectiveness and cost-utility assessment of IgGRT in CVID. We compared a mean literature-based dose (≥450mg/kg/4wks) to a zero-or-low dose (0 to ≤100 mg/kg/4wks) in a simulated cohort of adult patients from time of diagnosis until death; we also estimated the economic impact of diagnostic delay in this simulated cohort. Compared to no or minimal treatment, IgGRT showed an incremental benefit of 17 life-years (LYs) and 11 quality-adjusted life-years (QALYs), resulting in an incremental cost-effectiveness ratio (ICER) of €29,296/LY and €46,717/QALY. These results were robust in a sensitivity analysis. Reducing diagnostic delay by 4 years provided an incremental benefit of six LYs and four QALYs compared to simulated patients with delayed IgGRT initiation, resulting in an ICER of €30,374/LY and €47,495/QALY.

CONCLUSIONS: The health-economic model suggests that early initiation of IgGRT compared to no or delayed IgGRT is highly cost-effective. CVID-patients’ access to IgGRT should be facilitated, not only because of proven clinical efficacy, but also due to the now demonstrated cost-effectiveness.

PMID:33661975 | DOI:10.1371/journal.pone.0247941

Nucleic Acids Res. 2021 Feb 28:gkab118. doi: 10.1093/nar/gkab118. Online ahead of print.

ABSTRACT

Vertebrate genomes contain major (>99.5%) and minor (<0.5%) introns that are spliced by the major and minor spliceosomes, respectively. Major intron splicing follows the exon-definition model, whereby major spliceosome components first assemble across exons. However, since most genes with minor introns predominately consist of major introns, formation of exon-definition complexes in these genes would require interaction between the major and minor spliceosomes. Here, we report that minor spliceosome protein U11-59K binds to the major spliceosome U2AF complex, thereby supporting a model in which the minor spliceosome interacts with the major spliceosome across an exon to regulate the splicing of minor introns. Inhibition of minor spliceosome snRNAs and U11-59K disrupted exon-bridging interactions, leading to exon skipping by the major spliceosome. The resulting aberrant isoforms contained a premature stop codon, yet were not subjected to nonsense-mediated decay, but rather bound to polysomes. Importantly, we detected elevated levels of these alternatively spliced transcripts in individuals with minor spliceosome-related diseases such as Roifman syndrome, Lowry-Wood syndrome and early-onset cerebellar ataxia. In all, we report that the minor spliceosome informs splicing by the major spliceosome through exon-definition interactions and show that minor spliceosome inhibition results in aberrant alternative splicing in disease.

PMID:33660780 | DOI:10.1093/nar/gkab118

Turk Thorac J. 2021 Jan;22(1):37-44. doi: 10.5152/TurkThoracJ.2020.19077. Epub 2021 Jan 1.

ABSTRACT

OBJECTIVE: Bronchiectasis is characterized by chronic respiratory infection. The role of immunodeficiency in this disease is poorly studied in relation to clinical indices. The primary aim of this study was to determine the frequency of these neglected altered immune status by evaluating immunoglobulins, lymphocyte subsets, complement levels, and neutrophil function, and to assess its relationship with clinical parameters in adult patients with non-cystic fibrosis bronchiectasis (NCFB).

MATERIAL AND METHODS: A total of 74 (30 men and 44 women with a mean age of 47±17 years) adult patients with stable NCFB were enrolled in this study. The bronchiectasis severity index (BSI) and FACED (F:FEV1, A: Age, C: Chronic colonization, E: Extension, D: Dyspnea) scores were assessed. Peripheral blood samples were collected for the detection of total IgG, IgA, IgM, IgE, and IgG subclasses and C3 and C4 levels. The counts of CD3, CD4, CD8, CD19, CD16/56 expressing peripheral blood lymphocytes and neutrophil oxidative function were evaluated.

RESULTS: In the study population, BSI and FACED severity index scores increased with longer duration of the disease (p=0.01 and p=0.040, respectively). Of the 74 patients, 27 (37%) showed humoral aberrations. The number of male patients were higher in this group (p=0.03). High serum total IgE levels were associated with high scores in BSI (moderate-severe group versus mild group, p=0.030). Patients with bronchiectasis demonstrated lower CD3+ T cell count, lower CD4+ T helper cell percentage, and lower CD4+ T cell count (p=0.031, p=0.030, p=0.029, respectively) than healthy subjects. A significant negative correlation was found between the percentage and count of CD16/56+ natural killer (NK) cells and the number of exacerbations within the past year (r=-0.230, p=0.049 and r=-0.264, p=0.023, respectively).

CONCLUSION: Humoral aberrations in adult patients with NCFB were found to be frequent. IgE levels were related to high scores for disease severity indices. Furthermore, patients with low percentage and counts of NK cells had higher rates of exacerbations. These results emphasize the importance of immune function assessment in adult patients with NCFB.

PMID:33646102 | DOI:10.5152/TurkThoracJ.2020.19077

Front Immunol. 2021 Feb 11;12:634181. doi: 10.3389/fimmu.2021.634181. eCollection 2021.

ABSTRACT

Bacterial respiratory tract infections are the hallmark of primary antibody deficiencies (PADs). Because they are also among the most common infections in healthy individuals, PADs are usually overlooked in these patients. Careful evaluation of the history, including frequency, chronicity, and presence of other infections, would help suspect PADs. This review will focus on infections in relatively common PADs, discussing diagnostic challenges, and some management strategies to prevent infections.

PMID:33643318 | PMC:PMC7905085 | DOI:10.3389/fimmu.2021.634181