Publications by authors named "Glynis Frans"

20 Publications

  • Page 1 of 1

Delayed diagnosis and treatment of extreme hypertriglyceridemia due to rejection of a lipemic sample.

Biochem Med (Zagreb) 2021 Jun 15;31(2):021002. Epub 2021 Apr 15.

Clinical Department of Laboratory Medicine, University Hospitals Leuven, Leuven, Belgium.

Introduction: Most laboratories routinely determine haemolysis, icterus and lipemia indices to identify lipemic samples and reject potentially affected results. Hypertriglyceridemia is the most common cause of lipemia and severe hypertriglyceridemia (≥ 11.3 mmol/L) is a major risk factor of acute pancreatitis.

Laboratory Analysis: A 56-year-old woman attended the outpatient clinic for a follow-up visit 1 month after a kidney transplantation. Her immunosuppressive therapy consisted of corticosteroids, cyclosporine, and mycophenolic acid. The routine clinical chemistry sample was rejected due to extreme lipemia. The comment "extreme lipemic sample" was added on the report, but the requesting physician could not be reached. The Cobas 8000 gave a technical error (absorption > 3.3) for the HIL-indices (L-index: 38.6 mmol/L) which persisted after high-speed centrifugation. The patient was given a new appointment 2 days later. The new sample was also grossly lipemic and gave the same technical error (L-index: 35.9 mmol/L).

What Happened: The second sample was manually diluted 20-fold after centrifugation to obtain a result for triglycerides within the measuring range (0.10-50.0 mmol/L). Triglycerides were 169.1 mmol/L, corresponding to very severe hypertriglyceridemia. This result was communicated to the nephrologist and the patient immediately recalled to the hospital. She received therapeutic plasma exchange the next day and did not develop acute pancreatitis.

Main Lesson: This case illustrates the delicate balance between avoiding the release of unreliable results due to lipemia and the risk of delayed diagnosis when results are rejected. Providing an estimate of the degree of hypertriglyceridemia might be preferable to rejecting the result.
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http://dx.doi.org/10.11613/BM.2021.021002DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8047784PMC
June 2021

How to meet ISO15189:2012 pre-analytical requirements in clinical laboratories? A consensus document by the EFLM WG-PRE.

Clin Chem Lab Med 2021 May 15;59(6):1047-1061. Epub 2021 Jan 15.

Department of Medical Laboratory Diagnostics, University Hospital Sveti Duh, Zagreb, Croatia.

The International Organization for Standardization (ISO) 15189:2012 standard aims to improve quality in medical laboratories through standardization of all key elements in the total testing process, including the pre-analytical phase. It is hence essential that accreditation bodies, assessing laboratories against ISO15189:2012, pay sufficient attention to auditing pre-analytical activities. However, there are significant differences in how technical auditors interpret the pre-analytical requirements described in ISO15189:2012. In this consensus document, the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) Working Group for Pre-analytical Phase (WG-PRE) sets out to review pre-analytical requirements contained in ISO15189:2012 and provide guidance for laboratories on how to meet these requirements. The target audience for this consensus document is laboratory professionals who wish to improve the quality of the pre-analytical phase in their laboratory. For each of the ISO requirements described in ISO15189:2012, members of EFLM WG-PRE agreed by consensus on minimal recommendations and best-in-class solutions. The minimal consensus recommendation was defined as the minimal specification which laboratories should implement in their quality management system to adequately address the pre-analytical requirement described in ISO15189:2012. The best-in-class solution describes the current state-of-the-art in fulfilling a particular pre-analytical requirement in ISO15189:2012. We fully acknowledge that not every laboratory has the means to implement these best-in-class solutions, but we hope to challenge laboratories in critically evaluating and improving their current procedures by providing this expanded guidance.
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http://dx.doi.org/10.1515/cclm-2020-1859DOI Listing
May 2021

A case of severe pseudohyperkalaemia due to muscle contraction.

Biochem Med (Zagreb) 2020 Jun;30(2):021004

Clinical Department of Laboratory Medicine, University Hospitals Leuven, Leuven, Belgium.

Introduction: Severe hyperkalaemia is a serious medical condition requiring immediate medical attention. Before medical treatment is started, pseudohyperkalaemia has to be ruled out.

Case Description: A 10-month old infant presented to the emergency department with fever and coughing since 1 week. Routine venous blood testing revealed a severe hyperkalaemia of 6.9 mmol/L without any indication of haemolysis. Reanalysis of the plasma sample confirmed the hyperkalaemia (7.1 mmol/L). Based on these results, the clinical pathologist suggested to perform a venous blood gas analysis and electrocardiogram (ECG) which revealed a normal potassium of 3.7 mmol/L and normal ECG, ruling out a potentially life-treating hyperkalaemia. The child was diagnosed with pneumonia. The paediatrician had difficulty to perform the first venous blood collection due to excessive movement of the infant during venipuncture. The muscle contractions of the child in combination with venous stasis most probably led to a local increase of potassium in the sampled limbs. The second sample collected under optimal preanalytical circumstances had a normal potassium. Since muscle contraction typically does not cause severe hyperkalaemia, other causes of pseudohyperkalaemia were excluded. K-EDTA contamination and familial hyperkalaemia were ruled out and the patient did not have extreme leucocytosis or thrombocytosis. By exclusion a diagnosis of pseudohyperkalaemia due to intense muscle movement and venous stasis was made.

Conclusion: This case suggests that intense muscle contraction and venous stasis can cause severe pseudohyperkalemia without hemolysis. Once true hyperkalemia has been ruled out, a laboratory work-up can help identify the cause of pseudohyperkalaemia.
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http://dx.doi.org/10.11613/BM.2020.021004DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7271752PMC
June 2020

Resolving DOAC interference on aPTT, PT, and lupus anticoagulant testing by the use of activated carbon.

J Thromb Haemost 2019 08 12;17(8):1354-1362. Epub 2019 Jun 12.

Department of Laboratory Medicine, Onze-Lieve-Vrouw Ziekenhuis, Aalst, Belgium.

Background: Direct oral anticoagulants (DOACs) affect laboratory coagulations tests. Activated carbon (AC) can be used for adsorption of DOACs during acute human intoxications.

Objectives: This study evaluates whether AC can also be used to resolve DOAC interference on in vitro clotting tests (prothrombin time [PT], activated partial thromboplastin time [aPTT], and lupus anticoagulant [LA] assays).

Patients/methods: Interference on PT, aPTT, Liquid anti-FXa, DTI, and LA screening/confirmation (SCT and dRVVT) was determined by spiking citrated plasma from 5 adult controls with 0, 20, 40, 80, 120, or 160 mg/mL AC. DOAC concentrations, PT, and aPTT were compared before and after AC addition to citrated plasma from patients receiving DOACs (n = 29), low molecular weight heparin (n = 10), and coumarin (n = 10) therapy. Samples from 69 LA screened patients were compared before and after AC addition.

Results: A concentration of 20 mg/mL AC had the lowest interference and was selected for further experiments. After AC addition, all DOAC concentrations were below the limit of quantification in the 29 treated patients, except for 2 apixaban samples. AC removed DOAC interference on PT and aPTT but had no impact on results obtained during coumarin or low molecular weight heparin therapy. Of 15 LA samples with interference resulting from DOAC therapy, 14 samples became negative and 1 positive after AC addition. Interference from coumarin therapy was not resolved. All 19 LA negative samples remained negative. AC treatment of the negative pooled plasma was required to avoid false-negative LA results in 21 known LA-positive samples.

Conclusions: AC selectively removes DOAC interference on PT, aPTT, and LA assays.
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http://dx.doi.org/10.1111/jth.14488DOI Listing
August 2019

Migrating a lab-developed MERS-CoV real-time PCR to 3 "Sample to Result" systems: experiences on optimization and validation.

Diagn Microbiol Infect Dis 2019 Aug 10;94(4):349-354. Epub 2019 Feb 10.

Department of Laboratory Medicine, University Hospitals Leuven, Herestraat 49, 3000 Leuven, Belgium. Electronic address:

The goal of the study was to adapt our Middle East respiratory syndrome coronavirus (MERS-CoV) lab-developed test (LDT) to 3 "Sample to Result" (S2R) systems: BD MAX (BD), ELITe InGenius (ELITechGroup), and ARIES (Luminex). The BD MAX and InGenius system allowed use of lab-developed primers and TaqMan probes, while ARIES required conversion to MultiCode primers for melting curve analysis. Each device required ≤1 day of training and assay optimization. No discordant results were noted after analysis of 32 External Quality Control (EQC) samples. On a 10-fold dilution series of a MERS-CoV-positive EQC sample, InGenius obtained the highest detection rate. Laboratory technicians rated the ARIES as the user-friendliest. It also required the least hands-on time. BD MAX had the lowest turnaround time and highest throughput. While each device had distinguishing system properties with associated (dis)advantages, the 3 S2R systems were comparable in terms of assay development and validation.
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http://dx.doi.org/10.1016/j.diagmicrobio.2019.02.006DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7127711PMC
August 2019

Conventional and Single-Molecule Targeted Sequencing Method for Specific Variant Detection in IKBKG while Bypassing the IKBKGP1 Pseudogene.

J Mol Diagn 2018 03 18;20(2):195-202. Epub 2017 Dec 18.

Department of Human Genetics, KU Leuven, Leuven, Belgium. Electronic address:

In addition to Sanger sequencing, next-generation sequencing of gene panels and exomes has emerged as a standard diagnostic tool in many laboratories. However, these captures can miss regions, have poor efficiency, or capture pseudogenes, which hamper proper diagnoses. One such example is the primary immunodeficiency-associated gene IKBKG. Its pseudogene IKBKGP1 makes traditional capture methods aspecific. We therefore developed a long-range PCR method to efficiently target IKBKG, as well as two associated genes (IRAK4 and MYD88), while bypassing the IKBKGP1 pseudogene. Sequencing accuracy was evaluated using both conventional short-read technology and a newer long-read, single-molecule sequencer. Different mapping and variant calling options were evaluated in their capability to bypass the pseudogene using both sequencing platforms. Based on these evaluations, we determined a robust diagnostic application for unambiguous sequencing and variant calling in IKBKG, IRAK4, and MYD88. This method allows rapid identification of selected primary immunodeficiency diseases in patients suffering from life-threatening invasive pyogenic bacterial infections.
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http://dx.doi.org/10.1016/j.jmoldx.2017.10.005DOI Listing
March 2018

Functional Evaluation of an IKBKG Variant Suspected to Cause Immunodeficiency Without Ectodermal Dysplasia.

J Clin Immunol 2017 Nov 10;37(8):801-810. Epub 2017 Oct 10.

Department of Microbiology and Immunology, Experimental Laboratory Immunology, KU Leuven, Leuven, Belgium.

Hypomorphic IKBKG mutations in males are typically associated with anhidrotic ectodermal dysplasia with immunodeficiency (EDA-ID). Some mutations cause immunodeficiency without EDA (NEMO-ID). The immunological profile associated with these NEMO-ID variants is not fully documented. We present a 2-year-old patient with suspected immunodeficiency in which a hemizygous p.Glu57Lys IKBKG variant was identified. At the age of 1 year, he had an episode of otitis media that evolved into a bilateral mastoiditis (Pseudomonas spp). Hypogammaglobulinemia, specific (polysaccharide) antibody deficiency, and low switched memory B cell subsets were noticed. The mother was heterozygous for the variant but had no signs of incontinentia pigmenti. Patient peripheral blood mononuclear cells produced low amounts of IL-6 after stimulation with IL-1β, PamCSK and FSL-1. In patient fibroblasts, IκB-α was degraded normally upon stimulation with IL-1β or TNF-α. Transduction of wild-type and variant NEMO in NEMO deficient SV40 fibroblasts revealed a slight but significant reduction of IL-6 production upon stimulation with IL-1β and TNF-α. In conclusion, we demonstrated that p.Glu57Lys leads to specific immunological defects in vitro. No other pathogenic PID variants were identified through whole exome sequencing. As rare polymorphisms have been described in IKBKG and polygenic inheritance remains an option in the presented case, this study emphasizes the need for thorough functional and genetic evaluation when encountering and interpreting suspected disease-causing NEMO-ID variants.
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http://dx.doi.org/10.1007/s10875-017-0448-9DOI Listing
November 2017

Fifth Percentile Cutoff Values for Antipneumococcal Polysaccharide and Anti- Vi IgG Describe a Normal Polysaccharide Response.

Front Immunol 2017 12;8:546. Epub 2017 May 12.

Department Microbiology and Immunology, KU Leuven - University of Leuven, Leuven, Belgium.

Background: Serotype-specific antibody responses to unconjugated pneumococcal polysaccharide vaccine (PPV) evaluated by a World Health Organization (WHO)-standardized enzyme-linked immunosorbent assay (ELISA) are the gold standard for diagnosis of specific polysaccharide antibody deficiency (SAD). The American Academy of Allergy, Asthma and Immunology (AAAAI) has proposed guidelines to interpret the PPV response measured by ELISA, but these are based on limited evidence. Additionally, ELISA is costly and labor-intensive. Measurement of antibody response to () Vi vaccine and serum allohemagglutinins (AHA) have been suggested as alternatives. However, there are no large cohort studies and cutoff values are lacking.

Objective: To establish cutoff values for antipneumococcal polysaccharide antibody response, anti- Vi antibody, and AHA.

Methods: One hundred healthy subjects (10-55 years) were vaccinated with PPV and Vi vaccine. Blood samples were obtained prior to and 3-4 weeks after vaccination. Polysaccharide responses to 3 serotypes were measured by WHO ELISA and to 12 serotypes by an in-house bead-based multiplex assay. Anti- Vi IgG were measured with a commercial ELISA kit. AHA were measured by agglutination method.

Results: Applying AAAAI criteria, 30% of healthy subjects had a SAD. Using serotype-specific fifth percentile (p5) cutoff values for postvaccination IgG and fold increase pre- over postvaccination, only 4% of subjects had SAD. One-sided 95% prediction intervals for anti- Vi postvaccination IgG (≥11.2 U/ml) and fold increase (≥2) were established. Eight percent had a response to Vi vaccine below these cutoffs. AHA titer p5 cutoffs were ½ for anti-B and ¼ for anti-A.

Conclusion: We establish reference cutoff values for interpretation of PPV response measured by bead-based assay, cutoff values for Vi vaccine responses, and normal values for AHA. For the first time, the intraindividual consistency of all three methods is studied in a large cohort.
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http://dx.doi.org/10.3389/fimmu.2017.00546DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5427071PMC
May 2017

Clinical characteristics of patients with low functional IL-6 production upon TLR/IL-1R stimulation.

J Allergy Clin Immunol 2018 02 5;141(2):768-770. Epub 2017 May 5.

Department of Microbiology and Immunology, Experimental Laboratory Immunology, KU Leuven, Leuven, Belgium; Department of Laboratory Medicine, University Hospitals Leuven, Belgium. Electronic address:

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http://dx.doi.org/10.1016/j.jaci.2017.04.017DOI Listing
February 2018

A novel kindred with inherited STAT2 deficiency and severe viral illness.

J Allergy Clin Immunol 2017 06 10;139(6):1995-1997.e9. Epub 2017 Jan 10.

Department of Immunology and Microbiology, Autoimmune Genetics Laboratory, Vlaams Instituut Biotechnologie and KU Leuven, Leuven, Flanders, Belgium. Electronic address:

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http://dx.doi.org/10.1016/j.jaci.2016.10.033DOI Listing
June 2017

Novel Mutation of ZAP-70-related Combined Immunodeficiency: First Case from the National Iranian Registry and Review of the Literature.

Immunol Invest 2017 Jan 19;46(1):70-79. Epub 2016 Oct 19.

e Research Center for Immunodeficiencies, Pediatrics Center of Excellence , Children's Medical Center, Tehran University of Medical Sciences , Tehran , Iran.

ZAP-70 deficiency is a rare autosomal recessive form of combined immunodeficiency (CID) characterized by selective absence of circulating CD8 T cells with low, normal, or increased CD4 T cells in peripheral blood. Up to now, 14 unique mutations in the ZAP70 gene have been identified in patients with ZAP-70-related CID. We present a 3-year-old boy with a history of recurrent bacterial infections and autoimmunity. Initial laboratory findings showed a normal total lymphocyte count, but low levels of CD8 and CD4 T cells and an abnormal lymphocyte proliferation response. Immunoglobulin levels were normal, but the specific antibody response was impaired. Whole exome sequencing revealed a mutation within the kinase domain of ZAP-70. ZAP-70 deficiency should be considered in infants and young children with recurrent bacterial infections, in spite of having palpable lymph nodes, a notable thymus shadow, and a normal total lymphocyte count.
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http://dx.doi.org/10.1080/08820139.2016.1214962DOI Listing
January 2017

Homozygous N-terminal missense mutation in TRNT1 leads to progressive B-cell immunodeficiency in adulthood.

J Allergy Clin Immunol 2017 01 13;139(1):360-363.e6. Epub 2016 Aug 13.

Department of Microbiology and Immunology, Experimental Laboratory Immunology, KU Leuven, Leuven, Belgium; Department of Laboratory Medicine, University Hospitals Leuven, Leuven, Belgium. Electronic address:

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http://dx.doi.org/10.1016/j.jaci.2016.06.050DOI Listing
January 2017

Successful hematopoietic stem cell transplantation for myelofibrosis in an adult with warts-hypogammaglobulinemia-immunodeficiency-myelokathexis syndrome.

J Allergy Clin Immunol 2016 11 12;138(5):1485-1489.e2. Epub 2016 Jul 12.

Department of Microbiology and Immunology, Childhood Immunology, KU Leuven, Leuven, Belgium; Department of Pediatrics, University Hospitals Leuven, Leuven, Belgium. Electronic address:

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http://dx.doi.org/10.1016/j.jaci.2016.04.057DOI Listing
November 2016

Mild humoral immunodeficiency in a patient with X-linked Kabuki syndrome.

Am J Med Genet A 2016 Mar 24;170(3):801-3. Epub 2015 Dec 24.

Department of Microbiology and Immunology, Experimental Laboratory Immunology, KU Leuven, Leuven, Belgium.

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http://dx.doi.org/10.1002/ajmg.a.37499DOI Listing
March 2016

PID in Disguise: Molecular Diagnosis of IRAK-4 Deficiency in an Adult Previously Misdiagnosed With Autosomal Dominant Hyper IgE Syndrome.

J Clin Immunol 2015 Nov 15;35(8):739-44. Epub 2015 Oct 15.

Department of Microbiology and Immunology, Childhood Immunology, KU Leuven, Herestraat 49, 3000, Leuven, Belgium.

Autosomal recessive IL-1R-associated kinase 4 (IRAK-4) deficiency is a rare cause of recurrent pyogenic infections with limited inflammatory responses. We describe an adult female patient with severe lung disease who was phenotypically diagnosed as suffering from autosomal dominant Hyper IgE syndrome (AD HIES) because of recurrent skin infections with Staphylococcus aureus, recurrent pneumonia and elevated serum IgE levels. In contrast to findings in AD HIES patients, no abnormalities were found in the Th17 and circulating follicular helper T cell subsets. A panel-based sequencing approach led to the identification of a homozygous IRAK4 stop mutation (c.877C > T, p.Gln293*).
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http://dx.doi.org/10.1007/s10875-015-0205-xDOI Listing
November 2015

A novel hypomorphic mutation in STIM1 results in a late-onset immunodeficiency.

J Allergy Clin Immunol 2015 Sep 30;136(3):816-819.e4. Epub 2015 Apr 30.

Paris Descartes University - Sorbonne Paris Cité, Paris, France; Study Center for Immunodeficiency, Necker-Enfants Malades Hospital, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France; Laboratory of Human Genetics of Infectious Diseases, Necker Branch, INSERM UMR 1163, Institut IMAGINE, Paris, France. Electronic address:

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http://dx.doi.org/10.1016/j.jaci.2015.03.009DOI Listing
September 2015

Brief Report: IFIH1 Mutation Causes Systemic Lupus Erythematosus With Selective IgA Deficiency.

Arthritis Rheumatol 2015 Jun;67(6):1592-7

VIB and University of Leuven, Leuven, Belgium.

Objective: To identify the underlying genetic defect in a 16-year-old girl with severe early-onset and refractory systemic lupus erythematosus (SLE), IgA deficiency, and mild lower limb spasticity without neuroradiologic manifestations.

Methods: Whole-exome sequencing and extensive immunologic analysis were performed on samples from the index patient.

Results: We identified a de novo p.R779H IFIH1 gain-of-function mutation in a patient with severe early-onset SLE, selective IgA deficiency, and mild lower limb spasticity. The same mutation in IFIH1 was recently identified in patients with Aicardi-Goutières syndrome, a rare neuroimmunologic disorder associated with elevated levels of type I interferon (IFN). IFN induced with helicase C domain 1 functions as an intracellular innate immune receptor that senses viral nucleic acids and leads to the induction of type I IFN and proinflammatory cytokines. Despite systemic immunosuppressive treatment, disease activity persisted in the patient and was associated with elevated serum levels of IFNα and up-regulation of IFIH1 itself.

Conclusion: This finding adds a new genetic causation for Mendelian lupus and greatly extends the disease spectrum associated with mutations in IFIH1 (ranging from inflammatory encephalopathy to prototypic systemic autoimmune disease). This marked phenotypic heterogeneity, despite an identical mutation, demonstrates the importance of modifying factors in type I IFN-dependent pathologies caused by mutations in IFIH1.
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http://dx.doi.org/10.1002/art.39110DOI Listing
June 2015

Hematopoietic stem cell transplantation rescues the immunologic phenotype and prevents vasculopathy in patients with adenosine deaminase 2 deficiency.

J Allergy Clin Immunol 2015 Jan 25;135(1):283-7.e5. Epub 2014 Nov 25.

Department of Immunology and Microbiology, Childhood Immunology, Department of Pediatrics, University Hospitals Leuven and University of Leuven, Leuven, Belgium. Electronic address:

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http://dx.doi.org/10.1016/j.jaci.2014.10.010DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4282724PMC
January 2015

Addressing diagnostic challenges in primary immunodeficiencies: laboratory evaluation of Toll-like receptor- and NF-κB-mediated immune responses.

Crit Rev Clin Lab Sci 2014 Apr 18;51(2):112-23. Epub 2014 Feb 18.

Department of Microbiology and Immunology, Experimental Laboratory Immunology , KU Leuven, Leuven , Belgium .

Toll-like receptors (TLRs) play an important role in immunity and mediate their actions via multiple signaling pathways, in particular, the nuclear factor of kappa light polypeptide gene enhancer in B-cells (NF-κB) pathway. Rare inherited defects of TLR- and NF-κB-dependent responses have recently been recognized. These primary immunodeficiencies predispose children to life-threatening infections and often remain undiagnosed. Establishing a sensitive, specific, cost-effective and simple method for diagnosis is therefore important. In this article, we review the known defects of TLR- and NF-κB-mediated pathways and the assays that can be used to screen for such defects.
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http://dx.doi.org/10.3109/10408363.2014.881317DOI Listing
April 2014
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