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Tonsillar granuloma associated with hypogammaglobulinemia.

June 10, 2020 By Manish Butte

Tonsillar granuloma associated with hypogammaglobulinemia.

Allergy Asthma Clin Immunol. 2020;16:43

Authors: Laajala A, Kuismin O, Tastula M, Tiitto L, Kauppila S, Salo A, Åström P, Nissinen A, Glumoff V, Seppänen MRJ, Hautala T

Abstract
Background: Rare tonsillar granulomas may be caused for example by infections, malignancies or sarcoidosis. Granulomas also occur in inborn errors of immunity (IEI) such as common variable immunodeficiency (CVID) with B cell maturation defects and hypogammaglobulinemia. CVID shares various features with sarcoidosis and drug-induced secondary hypogammaglobulinemia; careful consideration of differential diagnosis between these conditions is warranted.
Case presentation: A 29-year-old female with epilepsy developed dysphagia, dyspnea and impaired exercise tolerance. Obstruction caused by swollen lingual tonsil and edema in the epiglottis and arytenoid mucosa were found. Lingual tonsil and epiglottis biopsies displayed non-necrotizing granulomas. There was no evidence of viral, bacterial, mycobacterial or fungal infections. Chest X-ray, computerized tomography of chest and ultrasound of neck and abdomen remained unremarkable. Positron emission tomography/computed tomography (PET/CT) showed laryngeal enhancement. Empiric antimicrobials combined with prednisolone were insufficient to control her disease. In immunological evaluation, the patient had normal counts of B and T cells. Proportions of CD27+ memory B cells (30.3%) and IgD-IgM-CD27+ switched memory B cells (7.2%; normal range 6.5-29.2%) were normal. Percentage of activated CD21low B cells was high (6.6%; normal range 0.6-3.5%). IgG (3.5 g/L; normal range 6.77-15.0 g/l) and all IgG subclass concentrations were low. Anti-polysaccharide responses were impaired, with 3/10 serotypes reaching a level of 0.35 µg/ml after immunization with Pneumovax®. The findings were consistent with hypogammaglobulinemia resembling CVID, possibly secondary to antiepileptic medication. Her dyspnea and dysphagia responded favorably to subcutaneous IgG and rituximab.
Conclusions: Tonsillar granulomas can be the presenting and only clinical feature of B cell deficiency, highlighting the diversity of symptoms and findings in primary or secondary immunodeficiencies.

PMID: 32514274 [PubMed]

Novel XIAP mutation causing enhanced spontaneous apoptosis and disturbed NOD2 signalling in a patient with atypical adult-onset Crohn’s disease.

June 10, 2020 By Manish Butte

Novel XIAP mutation causing enhanced spontaneous apoptosis and disturbed NOD2 signalling in a patient with atypical adult-onset Crohn’s disease.

Cell Death Dis. 2020 Jun 08;11(6):430

Authors: Parackova Z, Milota T, Vrabcova P, Smetanova J, Svaton M, Freiberger T, Kanderova V, Sediva A

Abstract
X-linked inhibitor of apoptosis (XIAP) is the most potent human inhibitor of apoptosis, and is also involved in NOD2-dependent NFκB and MAPK signalling cascade activation. The absence or defective function of XIAP leads to the development of a rare and severe primary immunodeficiency known as X-linked lymphoproliferative syndrome type 2 (XLP-2), which is characterized by a triad of clinical manifestations, including a high incidence of haemophagocytic lymphohistiocytosis (HLH), lymphoproliferation and inflammatory bowel disease (IBD), usually with very early onset. Here, we present a novel XIAP mutation identified in a patient with atypical adult-onset IBD complicated by relapsing HLH, splenomegaly and sarcoid-like disease. The c.266delA mutation in the XIAP gene creates a premature stop codon, and causes a severe reduction in XIAP protein expression. The mutation is also associated with impaired spontaneous and staurosporine- and PMA-induced apoptosis accompanied by significantly increased expression of pro-apoptotic genes. We also confirmed the negative impact of this particular XIAP mutation on NOD2-dependent NFκB and MAPK activation, while NOD2-independent activation was found to be unaffected. Moreover, we assume that the mutation has an impact on the overproduction of IL-12 and IFNγ, the shift towards the Th1 immune response and increased numbers of central memory and effector memory CD4+ and CD8+ T cells. All these changes contribute to immune dysregulation and the clinical manifestation of XLP-2.

PMID: 32514016 [PubMed – in process]

Innate effector systems in primary human macrophages sensitize multidrug resistant Klebsiella pneumoniae to antibiotics.

June 10, 2020 By Manish Butte

Innate effector systems in primary human macrophages sensitize multidrug resistant Klebsiella pneumoniae to antibiotics.

Infect Immun. 2020 Jun 08;:

Authors: Rekha RS, Karadottir H, Ahmed S, Gudmundsson GH, Agerberth B, Bergman P

Abstract
Infections caused by multidrug resistant (MDR) Klebsiella pneumoniae are difficult to treat with conventional antibiotics. Thus, alternative strategies to control the growth of MDR Klebsiella are warranted. We hypothesized that activation of innate effector systems could sensitize MDR Klebsiella to conventional antibiotics. Thus, human primary macrophages were stimulated with compounds known to activate innate immunity, vitamin D3, phenylbutyrate (PBA) and the aroylated phenylenediamine HO53, and then infected with MDR Klebsiella in the presence or absence of antibiotics. Antibiotics alone were ineffective against MDR Klebsiella in the cellular model, whereas VitD3, PBA and HO53 reduced intracellular growth by up to 70%. The effect was further improved when the innate activators were combined with antibiotics. VitD3 and PBA-induced bacterial killing was dependent on CAMP gene expression, whereas HO53 needed the production of reactive oxygen species (ROS), as shown in cells where the CYBB gene was silenced and in cells from a patient with reduced ROS-production due to a deletion in the CYBB-gene and skewed lyonization. The combination of innate effector activation by vitD3, PBA and HO53 was effective in sensitizing MDR Klebsiella to conventional antibiotics in a primary human macrophage model. This study provides new evidence for future treatment options for Klebsiella pneumonia.

PMID: 32513857 [PubMed – as supplied by publisher]

Tolerization of recent thymic emigrants is required to prevent RBC-specific autoimmunity.

June 9, 2020 By Manish Butte

Tolerization of recent thymic emigrants is required to prevent RBC-specific autoimmunity.

J Autoimmun. 2020 Jun 02;:102489

Authors: Wong ASL, Gruber DR, Richards AL, Sheldon K, Qiu A, Hay A, Hudson KE

Abstract
Autoimmune hemolytic anemia (AIHA) leads to accelerated destruction of autologous red blood cells (RBCs) by autoantibodies. AIHA is a severe and sometimes fatal disease. While there are several therapeutic strategies available, there are currently no licensed treatments for AIHA and few therapeutics result in treatment-free durable remission. The etiology of primary AIHA is unknown; however, secondary AIHA occurs concurrently with lymphoproliferative disorders and infections. Additionally, AIHA is the second most common manifestation of primary immunodeficiency disorders and has been described as a side effect of checkpoint inhibitor therapy. Given the severity of AIHA and the lack of treatment options, understanding the initiation of autoimmunity is imperative. Herein, we utilized a well-described model of RBC biology to dissect how RBC-specific autoreactive T cells become educated against RBC autoantigens. We show that, unlike most autoantigens, T cells do not encounter RBC autoantigens in the thymus. Instead, when they leave the thymus as recent thymic emigrants (RTEs), they retain the ability to positively respond to RBC autoantigens; only after several weeks in circulation do RTEs become nonresponsive. Together, these data suggest that any disruption in this process would lead to breakdown of tolerance and initiation of autoimmunity. Thus, RTEs and this developmental process are potential targets to prevent and treat AIHA.

PMID: 32507505 [PubMed – as supplied by publisher]

Late diagnosis of Chronic Granulomatous Disease.

June 9, 2020 By Manish Butte

Late diagnosis of Chronic Granulomatous Disease.

Clin Exp Immunol. 2020 Jun 07;:

Authors: Barkai T, Somech R, Broides A, Gavrieli R, Wolach B, Marcus N, Hagin D, Stauber T

Abstract
Modern era advancements in medical care, with improved treatment of infections, can result in delayed diagnosis of congenital immunodeficiencies. In this study we present a retrospective cohort of 16 patients diagnosed with Chronic Granulomatous Disease (CGD) at adulthood. Some of the patients had a milder clinical phenotype, but others had a classic phenotype with severe infectious and inflammatory complications reflecting a profoundly impaired neutrophil function. It is therefore of great importance to investigate the individual journey of each patient through different misdiagnoses and the threads which led to the correct diagnosis. Currently the recommended definitive treatment for CGD is hematopoietic stem cell transplantation (HSCT). Although survival of our patients to adulthood might argue against the need for early HSCT during infancy, we claim that the opposite is correct, as most of them grew to be severely ill and diagnosed at a stage when HSCT is debatable with potentially an unfavorable outcome. This cohort stresses the need to increase awareness of this severe congenital immunodeficiency among clinicians of different specialties who might be treating undiagnosed adult patients with CGD.

PMID: 32506450 [PubMed – as supplied by publisher]

Clinical Phenotypes and Immunological Characteristics of 18 Egyptian LRBA Deficiency Patients.

June 9, 2020 By Manish Butte

Clinical Phenotypes and Immunological Characteristics of 18 Egyptian LRBA Deficiency Patients.

J Clin Immunol. 2020 Jun 06;:

Authors: Meshaal S, El Hawary R, Adel R, Abd Elaziz D, Erfan A, Lotfy S, Hafez M, Hassan M, Johnson M, Rojas-Restrepo J, Gamez-Diaz L, Grimbacher B, Shoman W, Abdelmeguid Y, Boutros J, Galal N, El-Guindy N, Elmarsafy A

Abstract
LPS-responsive beige-like anchor (LRBA) deficiency is an autosomal recessive primary immunodeficiency disorder, OMIM (#614700). LRBA deficiency patients suffer from variable manifestations including recurrent infections, immune dysregulation, autoimmunity, cytopenias, and enteropathy. This study describes different clinical phenotypes and immunological characteristics of 18 LRBA deficiency patients diagnosed from Egypt. T and B lymphocyte subpopulations, LRBA, and cytotoxic T lymphocyte-associated protein 4 (CTLA4) expression were evaluated in resting and stimulated T cells using flow cytometry. Next-generation sequencing was used to identify mutations in the LRBA gene. LRBA deficiency patients had significantly lower B cells and increased percentage of memory T cells. CTLA4 levels were lower in LRBA-deficient T regulatory cells in comparison to healthy donors at resting conditions and significantly increased upon stimulation of T cells. We identified 11 novel mutations in LRBA gene ranging from large deletions to point mutations. Finally, we were able to differentiate LRBA-deficient patients from healthy control and common variable immunodeficiency patients using a simple flow cytometry test performed on whole blood and without need to prior stimulation. LRBA deficiency has heterogeneous phenotypes with poor phenotype-genotype correlation since the same mutation may manifest differently even within the same family. Low LRBA expression, low numbers of B cells, increased numbers of memory T cells, and defective CTLA4 expression (which increase to normal level upon T cell stimulation) are useful laboratory tests to establish the diagnosis of LRBA deficiency. Screening of the siblings of affected patients is very important as patients may be asymptomatic at the beginning of the disease course.

PMID: 32506362 [PubMed – as supplied by publisher]

Whole-Exome Sequencing-Based Approach for Germline Mutations in Patients with Inborn Errors of Immunity.

June 9, 2020 By Manish Butte

Whole-Exome Sequencing-Based Approach for Germline Mutations in Patients with Inborn Errors of Immunity.

J Clin Immunol. 2020 Jun 06;:

Authors: Okano T, Imai K, Naruto T, Okada S, Yamashita M, Yeh TW, Ono S, Tanaka K, Okamoto K, Tanita K, Matsumoto K, Toyofuku E, Kumaki-Matsumoto E, Okamura M, Ueno H, Ogawa S, Ohara O, Takagi M, Kanegane H, Morio T

Abstract
PURPOSE: Owing to recent technological advancements, using next-generation sequencing (NGS) and the accumulation of clinical experiences worldwide, more than 420 genes associated with inborn errors of immunity (IEI) have been identified, which exhibit large genotypic and phenotypic variations. Consequently, NGS-based comprehensive genetic analysis, including whole-exome sequencing (WES), have become more valuable in the clinical setting and have contributed to earlier diagnosis, improved treatment, and prognosis. However, these approaches have the following disadvantages that need to be considered: a relatively low diagnostic rate, high cost, difficulties in the interpretation of each variant, and the risk of incidental findings. Thus, the objective of this study is to review our WES results of a large number of patients with IEI and to elucidate patient characteristics, which are related to the positive WES result.
METHODS: We performed WES for 136 IEI patients with negative conventional screening results for candidate genes and classified these variants depending on validity of their pathogenicity.
RESULTS: We identified disease-causing pathogenic mutations in 36 (26.5%) of the patients which were found in known IEI-causing genes. Although the overall diagnostic rate was not high and was not apparently correlated with the clinical subcategories and severity, we revealed that earlier onset with longer duration of diseases were associated with positive WES results, especially in pediatric cases.
CONCLUSIONS: Most of the disease-causing germline mutations were located in the known IEI genes which could be predicted using patients’ clinical characteristics. These results may be useful when considering appropriate genetic approaches in the clinical setting.

PMID: 32506361 [PubMed – as supplied by publisher]

FOXN1 compound heterozygous mutations cause selective thymic hypoplasia in humans.

June 9, 2020 By Manish Butte

Icon for American Society for Clinical Investigation

FOXN1 compound heterozygous mutations cause selective thymic hypoplasia in humans.

J Clin Invest. 2019 11 01;129(11):4724-4738

Authors: Du Q, Huynh LK, Coskun F, Molina E, King MA, Raj P, Khan S, Dozmorov I, Seroogy CM, Wysocki CA, Padron GT, Yates TR, Markert ML, de la Morena MT, van Oers NS

Abstract
We report on 2 patients with compound heterozygous mutations in forkhead box N1 (FOXN1), a transcription factor essential for thymic epithelial cell (TEC) differentiation. TECs are critical for T cell development. Both patients had a presentation consistent with T-/loB+NK+ SCID, with normal hair and nails, distinct from the classic nude/SCID phenotype in individuals with autosomal-recessive FOXN1 mutations. To understand the basis of this phenotype and the effects of the mutations on FOXN1, we generated mice using CRISPR-Cas9 technology to genocopy mutations in 1 of the patients. The mice with the Foxn1 compound heterozygous mutations had thymic hypoplasia, causing a T-B+NK+ SCID phenotype, whereas the hair and nails of these mice were normal. Characterization of the functional changes due to the Foxn1 mutations revealed a 5-amino acid segment at the end of the DNA-binding domain essential for the development of TECs but not keratinocytes. The transcriptional activity of this Foxn1 mutant was partly retained, indicating a region that specifies TEC functions. Analysis of an additional 9 FOXN1 mutations identified in multiple unrelated patients revealed distinct functional consequences contingent on the impact of the mutation on the DNA-binding and transactivation domains of FOXN1.

PMID: 31566583 [PubMed – indexed for MEDLINE]

Comprehensive RNA-Seq profiling of the lung transcriptome of Argali hybrid sheep in response to experimental Mycoplasma ovipneumoniae infection.

June 7, 2020 By Manish Butte

Comprehensive RNA-Seq profiling of the lung transcriptome of Argali hybrid sheep in response to experimental Mycoplasma ovipneumoniae infection.

Res Vet Sci. 2020 May 21;132:57-68

Authors: Li Z, Du Z, Sun Y, Wang J, Liu H, Yang Y, Zhao N

Abstract
BACKGROUND: An experiment was conducted to reveal why the Argali hybrid sheep are susceptible to Mycoplasma ovipneumoniae infection, the causative agent of mycoplasma ovipneumonia, a chronic respiratory disease that is harmful to the sheep industry.
RESULTS: After nine Argali hybrid sheep, divided into three groups, were experimentally infected with an M. ovipneumoniae strain at 0, 4 and 14 days, transcriptome profiling of lung tissues was performed by deep RNA sequencing, using the Illumina platform. Analysis of differentially expressed genes was performed to determine concomitant gene-specific temporal patterns of mRNA expression in the lungs after M. ovipneumoniae infection. 156 differentially expressed genes (44 up-regulated, 112 down-regulated) were found when comparing transcriptomic data at 4 and 0 days post-infection, and 367 (35 up-regulated, 332 down-regulated) when comparing 14 versus 0 days post-infection. Kyoto Encyclopedia of Genes and Genomes pathway analysis showed that the differentially expressed genes at 4 and 14 versus 0 days post-infection were enriched in 109 and 150 pathways, respectively, and the Primary immunodeficiency pathway was considered most closely related to MO infection (p < .01). Hyper-IgM syndrome was identified based on the B-cell Immunodeficiency signaling pathway from differentially expressed genes related to M. ovipneumoniae infection. Gene Ontology analysis showed that differentially expressed genes in different groups were enriched for 497 and 928 terms, where those most closely related to M. ovipneumoniae infection are ciliated motor damage (p < .01).
CONCLUSIONS: The situation that ciliary movement is significantly inhibited and B cells in immunodeficiency are possibly the most important reason why Argali hybrid sheep are susceptible to MO.

PMID: 32505020 [PubMed – as supplied by publisher]

Whole-genome sequencing of a sporadic primary immunodeficiency cohort.

June 6, 2020 By Manish Butte

Whole-genome sequencing of a sporadic primary immunodeficiency cohort.

Nature. 2020 May 06;:

Authors: Thaventhiran JED, Lango Allen H, Burren OS, Rae W, Greene D, Staples E, Zhang Z, Farmery JHR, Simeoni I, Rivers E, Maimaris J, Penkett CJ, Stephens J, Deevi SVV, Sanchis-Juan A, Gleadall NS, Thomas MJ, Sargur RB, Gordins P, Baxendale HE, Brown M, Tuijnenburg P, Worth A, Hanson S, Linger RJ, Buckland MS, Rayner-Matthews PJ, Gilmour KC, Samarghitean C, Seneviratne SL, Sansom DM, Lynch AG, Megy K, Ellinghaus E, Ellinghaus D, Jorgensen SF, Karlsen TH, Stirrups KE, Cutler AJ, Kumararatne DS, Chandra A, Edgar JDM, Herwadkar A, Cooper N, Grigoriadou S, Huissoon AP, Goddard S, Jolles S, Schuetz C, Boschann F, Primary Immunodeficiency Consortium for the NIHR Bioresource, Lyons PA, Hurles ME, Savic S, Burns SO, Kuijpers TW, Turro E, Ouwehand WH, Thrasher AJ, Smith KGC

Abstract
Primary immunodeficiency (PID) is characterized by recurrent and often life-threatening infections, autoimmunity and cancer, and it poses major diagnostic and therapeutic challenges. Although the most severe forms of PID are identified in early childhood, most patients present in adulthood, typically with no apparent family history and a variable clinical phenotype of widespread immune dysregulation: about 25% of patients have autoimmune disease, allergy is prevalent and up to 10% develop lymphoid malignancies1-3. Consequently, in sporadic (or non-familial) PID genetic diagnosis is difficult and the role of genetics is not well defined. Here we address these challenges by performing whole-genome sequencing in a large PID cohort of 1,318 participants. An analysis of the coding regions of the genome in 886 index cases of PID found that disease-causing mutations in known genes that are implicated in monogenic PID occurred in 10.3% of these patients, and a Bayesian approach (BeviMed4) identified multiple new candidate PID-associated genes, including IVNS1ABP. We also examined the noncoding genome, and found deletions in regulatory regions that contribute to disease causation. In addition, we used a genome-wide association study to identify loci that are associated with PID, and found evidence for the colocalization of-and interplay between-novel high-penetrance monogenic variants and common variants (at the PTPN2 and SOCS1 loci). This begins to explain the contribution of common variants to the variable penetrance and phenotypic complexity that are observed in PID. Thus, using a cohort-based whole-genome-sequencing approach in the diagnosis of PID can increase diagnostic yield and further our understanding of the key pathways that influence immune responsiveness in humans.

PMID: 32499645 [PubMed – as supplied by publisher]