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Beulaja Manikandan S, Manikandan R, Arumugam M, Mullainadhan P. An overview on human serum lectins. Heliyon 2020; 6:e04623. [PMID: 32923708 PMCID: PMC7475231 DOI: 10.1016/j.heliyon.2020.e04623] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 07/16/2020] [Accepted: 07/31/2020] [Indexed: 01/25/2023] Open
Abstract
An extensive literature survey done on the various naturally occurring lectins in human serum upon its salient features such as methods of detection, level and sites of synthesis, binding specificity, cation dependency, modes of isolation, molecular and functional characterization way back from 1930s to till date was presented in a tabulated section. In addition, the generation of lectin and other immune molecules in vertebrates upon treatment with exogenous elicitors has also been framed in a tabular form. Furthermore, ANEW lectin induced in human serum for the very first time by an exogenous elicitor was detected, isolated and characterized by us whose features are also tabulated explicitly.
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Affiliation(s)
- S. Beulaja Manikandan
- Department of Biochemistry, Annai Veilankanni's College for Women, Saidapet, Chennai, Tamilnadu, 600015, India
| | - R. Manikandan
- Department of Zoology, University of Madras, Guindy Campus, Chennai, Tamilnadu, 600025, India
| | - M. Arumugam
- Department of Zoology, University of Madras, Guindy Campus, Chennai, Tamilnadu, 600025, India
| | - P. Mullainadhan
- Department of Zoology, University of Madras, Guindy Campus, Chennai, Tamilnadu, 600025, India
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2
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Berger BE. Atypical hemolytic uremic syndrome: a syndrome in need of clarity. Clin Kidney J 2019; 12:338-347. [PMID: 31198222 PMCID: PMC6543964 DOI: 10.1093/ckj/sfy066] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Indexed: 12/24/2022] Open
Abstract
Atypical hemolytic uremic syndrome (aHUS) is a thrombotic microangiopathy (TMA) originally understood to be limited to renal and hematopoietic involvement. Whereas aberrations in complement regulatory proteins (CRPs), C3 or complement factor B (CFB) are detected in ∼60% of patients, a complement-derived pathogenesis that reflects dysregulation of the alternative pathway (AP) of complement activation is present in ∼90% of patients. aHUS remains a diagnosis of exclusion. The discovery of a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS13) and its utility in the diagnosis of thrombotic thrombocytopenic purpura (TTP) has resulted in the appreciation that cases of aHUS have been inappropriately diagnosed as TTP. Thus there has been an evolving appreciation of clinical manifestations of aHUS that renders the appellation aHUS misleading. This article will review the pathogenesis and the evolving clinical presentations of aHUS, present a hypothesis that there can be a phenotypic expression of aHUS due to a complement storm in a disorder where direct endothelial damage occurs and discuss future areas of research to more clearly define the clinical spectrum and management of aHUS.
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Affiliation(s)
- Bruce E Berger
- School of Medicine, Case Western Reserve University, Cleveland, OH, USA
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Wood CBS. Immune Deficiency. Proc R Soc Med 2016. [DOI: 10.1177/003591577707001209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- C B S Wood
- Academic Department of Child Health, Queen Elizabeth Hospital for Children, Hackney Road, London E2 8PS
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Zinyama-Gutsire RBL, Christiansen M, Hedley PL, Rusakaniko S, Hagen C, Stray-Pedersen B, Buzdugan R, Cowan F, Chasela C. HIV-1 Vertical Transmission in Zimbabwe in 622 Mother and Infant Pairs: Rethinking the Contribution of Mannose Binding Lectin Deficiency in Africa. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2016; 20:433-41. [PMID: 27315016 DOI: 10.1089/omi.2016.0056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Vertical transmission of human immunodeficiency virus (HIV) remains a major global health problem. We assessed the association of mannose binding lectin (MBL) deficiency and vertical transmission of HIV. Novel diagnostics would be a major breakthrough in this regard. MBL is a liver-derived protein and a key component of the innate immune system. MBL levels may be classified as normal, intermediate, or deficient in the plasma and can use MBL2 haplotypes as a proxy. These haplotypes comprise polymorphisms in the MBL2 gene and promoter region and are known to result in varying levels of MBL deficiency. MBL deficiency can be defined as presence of A/O and O/O genotypes in the mothers and their children. MBL deficiency leads to defective opsonization activities of the innate immune system and increased susceptibility to several infections, including HIV-1. We determined the prevalence of MBL deficiency, using MBL2 haplotypes among 622 HIV-positive Zimbabwean mothers and their children aged 9-18 months old, in relation to the HIV-1 vertical transmission risk. The median age of the mothers was 30 (26-34, interquartile range [IQR]) years, and the babies' median age was 13 (11-15, IQR) months old at the time of enrollment. From the sample of 622 mothers who were HIV-1 infected, 574 babies were HIV negative and 48 were HIV-1-positive babies, giving a transmission rate of 7.7%. MBL2 normal structural allele A and variants B (codon 5 A>G), C (codon 57 A>G), and promoter region SNPs -550(H/L) and -221(X/Y) were detected. Prevalence of haplotype-predicted MBL deficiency was 34% among the mothers and 32% among the children. We found no association between maternal MBL2 deficiency and HIV-1 transmission to their children. We found no difference in the distribution of HIV-1 infected and uninfected children between the MBL2 genotypes of the mothers and those of the children. Taken together, the present study in a large sample of mother-infant pairs in Zimbabwe adds to the emerging literature and the hypothesis that MBL2 variation as predicted by haplotypes does not influence the vertical transmission risk for HIV. Research from other populations from the African continent is called for to test this hypothesis further.
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Affiliation(s)
- Rutendo B L Zinyama-Gutsire
- 1 Faculty of Health Sciences, School of Public Health, University of the Witwatersrand , Johannesburg, South Africa .,2 Medical Research Council of Zimbabwe , Ministry of Health and Child Welfare, Harare, Zimbabwe .,3 Letten Research Foundation , Harare, Zimbabwe .,4 Department of Congenital Disorders, Statens Serum Institut , Copenhagen, Denmark
| | - Michael Christiansen
- 4 Department of Congenital Disorders, Statens Serum Institut , Copenhagen, Denmark
| | - Paula L Hedley
- 4 Department of Congenital Disorders, Statens Serum Institut , Copenhagen, Denmark
| | - Simbarashe Rusakaniko
- 3 Letten Research Foundation , Harare, Zimbabwe .,5 College of Health Sciences, University of Zimbabwe , Harare, Zimbabwe
| | - Christian Hagen
- 4 Department of Congenital Disorders, Statens Serum Institut , Copenhagen, Denmark
| | - Babill Stray-Pedersen
- 3 Letten Research Foundation , Harare, Zimbabwe .,5 College of Health Sciences, University of Zimbabwe , Harare, Zimbabwe .,6 Division of Women and Children, Rikshospitalet Oslo University Hospital, Institute of Clinical Medicine, University of Oslo , Oslo, Norway
| | - Raluca Buzdugan
- 7 School of Public Health, University of California , Berkeley, California
| | | | - Charles Chasela
- 1 Faculty of Health Sciences, School of Public Health, University of the Witwatersrand , Johannesburg, South Africa .,9 Epidemiology and Strategic Information Unit, HIV/AIDS, STIs and TB (HAST), Human Sciences Research Council , Pretoria, South Africa
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Berger BE. The Alternative Pathway of Complement and the Evolving Clinical-Pathophysiological Spectrum of Atypical Hemolytic Uremic Syndrome. Am J Med Sci 2016; 352:177-90. [PMID: 27524217 DOI: 10.1016/j.amjms.2016.05.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 03/31/2016] [Accepted: 05/03/2016] [Indexed: 01/31/2023]
Abstract
Complement-mediated atypical hemolytic uremic syndrome (aHUS) comprises approximately 90% of cases of aHUS, and results from dysregulation of endothelial-anchored complement activation with resultant endothelial damage. The discovery of biomarker ADAMTS13 has enabled a more accurate diagnosis of thrombotic thrombocytopenic purpura (TTP) and an appreciation of overlapping clinical features of TTP and aHUS. Given our present understanding of the pathogenic pathways involved in aHUS, it is unlikely that a specific test will be developed. Rather the use of biomarker data, complement functional analyses, genomic analyses and clinical presentation will be required to diagnose aHUS. This approach would serve to clarify whether a thrombotic microangiopathy present in a complement-amplifying condition arises from the unmasking of a genetically driven aHUS versus a time-limited complement storm-mediated aHUS due to direct endothelial damage in which no genetic predisposition is present. Although both scenarios result in the phenotypic expression of aHUS and involve the alternate pathway of complement activation, long-term management would differ.
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Affiliation(s)
- Bruce E Berger
- School of Medicine, Case Western Reserve University, Cleveland, Ohio.
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Almroth Wright, opsonins, innate immunity and the lectin pathway of complement activation: a historical perspective. Microbes Infect 2016; 18:450-9. [PMID: 27109231 DOI: 10.1016/j.micinf.2016.04.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 04/08/2016] [Accepted: 04/11/2016] [Indexed: 01/03/2023]
Abstract
Two clinical tests - the erythrocyte sedimentation rate and the opsonic index - have long been known to non-specifically detect pathology based on their responsiveness to changes in serum proteins. In infections serum levels of specific antibodies increase. However, for healthy subjects Wright held that antibodies contributed minimally to opsonic activity (the complement-enhanced phagocytosis of microorganisms). The activity was present in newborn serum, was increased in the acute phase of an immune response prior to antibody increase, and was less specific. Furthermore, defective opsonization was associated with undue susceptibility to certain infections, for which a genetic basis was later found. With the demonstrations of complement-mediated lysis both of normal cells by foreign (plant) lectins, and of foreign cells (microorganisms) by animal lectins, it now appears that endogenous lectins correspond to the heat-stable component of Wright's serum opsonic activity. His work leads to the lectin pathway of complement activation with specificities limited to the recognition of relatively immutable surface sugars - predictable pathogen characters that contrast with the less predictable targets of the adaptive immune system.
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Eisen DP. Editorial Commentary: Shall We Disregard Mannose-Binding Lectin Modification in the Future Because We Cannot Prevent Sepsis With This Molecule? Clin Infect Dis 2015; 61:704-6. [DOI: 10.1093/cid/civ380] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 05/01/2015] [Indexed: 01/02/2023] Open
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Ibernon M, Moreso F, Serón D. Innate immunity in renal transplantation: The role of mannose-binding lectin. Transplant Rev (Orlando) 2014; 28:21-5. [DOI: 10.1016/j.trre.2013.10.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 10/18/2013] [Accepted: 10/21/2013] [Indexed: 01/17/2023]
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Boldt ABW, Goeldner I, de Messias-Reason IJT. Relevance of the lectin pathway of complement in rheumatic diseases. Adv Clin Chem 2012; 56:105-53. [PMID: 22397030 DOI: 10.1016/b978-0-12-394317-0.00012-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Due to its importance both in the clearance of pathogens that contribute as rheumatic etiological agents and in the disposal of apoptotic bodies and potential autoimmune initiators, deficiencies of the components of the lectin pathway of complement have been found to increase susceptibility and modulate the severity of most rheumatic disorders. This chapter introduces the general aspects of the structure, function, and genetics of lectin pathway components and summarizes current knowledge of the field regarding rheumatic diseases predisposition and modulation.
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Affiliation(s)
- Angelica B W Boldt
- Molecular Immunopathology Laboratory, Department of Medical Pathology, Federal University of Paraná, Curitiba, Brazil
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Infections of people with complement deficiencies and patients who have undergone splenectomy. Clin Microbiol Rev 2010; 23:740-80. [PMID: 20930072 DOI: 10.1128/cmr.00048-09] [Citation(s) in RCA: 254] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The complement system comprises several fluid-phase and membrane-associated proteins. Under physiological conditions, activation of the fluid-phase components of complement is maintained under tight control and complement activation occurs primarily on surfaces recognized as "nonself" in an attempt to minimize damage to bystander host cells. Membrane complement components act to limit complement activation on host cells or to facilitate uptake of antigens or microbes "tagged" with complement fragments. While this review focuses on the role of complement in infectious diseases, work over the past couple of decades has defined several important functions of complement distinct from that of combating infections. Activation of complement in the fluid phase can occur through the classical, lectin, or alternative pathway. Deficiencies of components of the classical pathway lead to the development of autoimmune disorders and predispose individuals to recurrent respiratory infections and infections caused by encapsulated organisms, including Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae. While no individual with complete mannan-binding lectin (MBL) deficiency has been identified, low MBL levels have been linked to predisposition to, or severity of, several diseases. It appears that MBL may play an important role in children, who have a relatively immature adaptive immune response. C3 is the point at which all complement pathways converge, and complete deficiency of C3 invariably leads to severe infections, including those caused by meningococci and pneumococci. Deficiencies of the alternative and terminal complement pathways result in an almost exclusive predisposition to invasive meningococcal disease. The spleen plays an important role in antigen processing and the production of antibodies. Splenic macrophages are critical in clearing opsonized encapsulated bacteria (such as pneumococci, meningococci, and Escherichia coli) and intraerythrocytic parasites such as those causing malaria and babesiosis, which explains the fulminant nature of these infections in persons with anatomic or functional asplenia. Paramount to the management of patients with complement deficiencies and asplenia is educating patients about their predisposition to infection and the importance of preventive immunizations and seeking prompt medical attention.
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Grundmann S, Bode C, Moser M. Mannose-binding lectin: an ancient molecule with new implications in myocardial infarction. Eur Heart J 2010; 31:1163-4. [PMID: 20233793 DOI: 10.1093/eurheartj/ehq070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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13
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Abstract
The complement system is composed of more than 30 serum and membrane-bound proteins, all of which are needed for normal function of complement in innate and adaptive immunity. Historically, deficiencies within the complement system have been suspected when young children have had recurrent and difficult-to-control infections. As our understanding of the complement system has increased, many other diseases have been attributed to deficiencies within the complement system. Generally, complement deficiencies within the classical pathway lead to increased susceptibility to encapsulated bacterial infections as well as a syndrome resembling systemic lupus erythematosus. Complement deficiencies within the mannose-binding lectin pathway generally lead to increased bacterial infections, and deficiencies within the alternative pathway usually lead to an increased frequency of Neisseria infections. However, factor H deficiency can lead to membranoproliferative glomerulonephritis and hemolytic uremic syndrome. Finally, deficiencies within the terminal complement pathway lead to an increased incidence of Neisseria infections. Two other notable complement-associated deficiencies are complement receptor 3 and 4 deficiency, which result from a deficiency of CD18, a disease known as leukocyte adhesion deficiency type 1, and CD59 deficiency, which causes paroxysmal nocturnal hemoglobinuria. Most inherited deficiencies of the complement system are autosomal recessive, but properidin deficiency is X-linked recessive, deficiency of C1 inhibitor is autosomal dominant, and mannose-binding lectin and factor I deficiencies are autosomal co-dominant. The diversity of clinical manifestations of complement deficiencies reflects the complexity of the complement system.
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Affiliation(s)
- H David Pettigrew
- Division of Rheumatology, Allergy and Clinical Immunology, University of California at Davis School of Medicine, Davis, California 95616, USA
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Faro J, Chen Y, Jhaveri P, Oza P, Spear GT, Lint TF, Gewurz H. L-ficolin binding and lectin pathway activation by acetylated low-density lipoprotein. Clin Exp Immunol 2008; 151:275-83. [PMID: 18031558 PMCID: PMC2276939 DOI: 10.1111/j.1365-2249.2007.03538.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/25/2007] [Indexed: 11/28/2022] Open
Abstract
L-ficolin, like mannan-binding lectin (MBL), is a lectin pathway activator present in normal human plasma. Upon binding ligand, l-ficolin similarly initiates C4 cleavage via the serine protease MBL-associated serine protease-2 (MASP-2). We sought further insight into l-ficolin binding reactions and MASP-2 activation by passing plasma through GlcNAc-derivatized Sepharose. l-Ficolin bound in 1.0 M NaCl-ethylenediamine tetraacetic acid (EDTA), and remained bound in NaCl-free EDTA, while MASP-2 eluted in proenzyme form ( approximately 20% yield, > 40 000-fold purification). L-Ficolin was eluted with GlcNAc in 1.0 M NaCl ( approximately 10% yield, > 3000-fold purification), with trace amounts of C3, alpha(2)-macroglobulin and both native and activated MASP-2. These preparations were utilized to investigate l-ficolin reactivities with acetylated low-density lipoprotein (A-LDL) as a model ligand in albumin-free systems. L-Ficolin bound strongly to A-LDL in the absence as well as presence of calcium, including saline-EDTA, and was optimal in 1.0 M NaCl-EDTA, but binding failed to occur in EDTA in the absence of NaCl. The addition of l-ficolin to immobilized A-LDL resulted in activation of MASP-2 in unmodified but not ficolin-depleted plasma unless l-ficolin was restored. We conclude that A-LDL is a useful ligand for investigation of l-ficolin function; both binding and activation are optimally examined in systems free of albumin; and ligand binding in 1.0 M NaCl in EDTA can be useful in the isolation of l-ficolin and native MASP-2.
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Affiliation(s)
- J Faro
- Department of Immunology/Microbiology, Rush Medical College, Chicago, IL 60612, USA.
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Primary Immunodeficiencies. PEDIATRIC ALLERGY, ASTHMA AND IMMUNOLOGY 2008. [PMCID: PMC7121684 DOI: 10.1007/978-3-540-33395-1_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Primary immunodeficiencies (PIDs), once considered to be very rare, are now increasingly recognized because of growing knowledge in the immunological field and the availability of more sophisticated diagnostic techniques and therapeutic modalities [161]. However in a database of >120,000 inpatients of a general hospital for conditions suggestive of ID 59 patients were tested, and an undiagnosed PID was found in 17 (29%) of the subjects tested [107]. The publication of the first case of agammaglobulinemia by Bruton in 1952 [60] demonstrated that the PID diagnosis is first done in the laboratory. However, PIDs require specialized immunological centers for diagnosis and management [33]. A large body of epidemiological evidence supports the hypothesis of the existence of a close etiopathogenetic relation between PID and atopy [73]. In particular, an elevated frequency of asthma, food allergy (FA), atopic dermatitis and enteric pathologies can be found in various PIDs. In addition we will discuss another subject that is certainly of interest: the pseudo-immunodepressed child with recurrent respiratory infections (RRIs), an event that often requires medical intervention and that very often leads to the suspicion that it involves antibody deficiencies [149].
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Takahashi K, Ezekowitz RAB. The role of the mannose-binding lectin in innate immunity. Clin Infect Dis 2007; 41 Suppl 7:S440-4. [PMID: 16237644 DOI: 10.1086/431987] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
The innate immune system, which includes mannose-binding lectin (MBL), recognizes a broad range of molecular patterns on a broad range of infectious agents and is able to distinguish them from self. MBL is a liver-derived serum protein and is secreted into the serum, where it can activate an immune response before the induction of antigen-specific immunity. Circumstantial evidence in human populations suggests that low serum levels of MBL predispose to infection. To analyze the role of MBL in vivo, we created MBL-null mice and challenged these mice with infection under various conditions. Our results suggest that MBL plays an important role as a first-line host defense against certain infectious agents. In addition, it is likely that MBL is a key regulator of inflammation beyond expected roles in the infection.
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Affiliation(s)
- Kazue Takahashi
- Department of Pediatrics, Harvard Medical School, Massachusetts General Hospital, Boston, MA 02114, USA.
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Abstract
The human collectin, mannose‐binding lectin (MBL), is an important protein of the humoral innate immune system. With multiple carbohydrate‐recognition domains, it is able to bind to sugar groups displayed on the surfaces of a wide range of microorganisms and thereby provide first‐line defence. Importantly, it also activates the complement system through a distinctive third pathway, independent of both antibody and the C1 complex. Three single point mutations in exon 1 of the expressed human MBL‐2 gene appear to impair the generation of functional oligomers. Such deficiencies of functional protein are common in certain populations, e.g. in sub‐Saharan Africa, but virtually absent in others, e.g. indigenous Australians. MBL disease association studies have been a fruitful area of research and implicate a role for MBL in infective, inflammatory and autoimmune disease processes. Overall, there appears to be a genetic balance in which individuals generally benefit from high levels of the protein. However, in certain situations, reduced levels of circulating MBL may be beneficial to the host and this may explain the persistence of the deleterious gene polymorphisms in many population groups.
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Affiliation(s)
- R M Dommett
- Infectious Diseases and Microbiology Unit, Institute of Child Health, UCL, 30 Guilford Street, London WC1N 1EH, UK
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Affiliation(s)
- Virendra N Sehgal
- Dermato-Venereology, Skin/VD Center, Sehgal Nursing Home, Panchwati, Azadpur, Delhi, India.
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Aittoniemi J, Soranummi H, Rovio AT, Hurme M, Pessi T, Nieminen M, Karjalainen J. Mannose-binding lectin 2 (MBL2) gene polymorphism in asthma and atopy among adults. Clin Exp Immunol 2005; 142:120-4. [PMID: 16178865 PMCID: PMC1809495 DOI: 10.1111/j.1365-2249.2005.02881.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Mannose-binding lectin (MBL) insufficiency due to polymorphisms in the MBL2 gene causes an opsonization defect, which has been connected to infections and atopy. We investigated the significance of MBL2 genotypes with regard to persistent asthma and atopy among adults. The genotypes were determined in 243 adults with persistent asthma and 400 controls. Atopy was determined by skin-prick test. As a result, the carriage of -221 base pairs (bp) promoter region variant allele X (nucleotide change G-->C; alleles Y-->X, respectively) causing low MBL expression proved to be a significant risk factor for asthma in non-atopic males [odds ratio (OR) = 2.52, 95% confidence interval (CI) = 1.23-5.15; P = 0.01]. Furthermore, the X-allele carriage was associated with the decrease in lung function (forced expiratory volume at 1 s, FEV(1)) during follow-up in the patients with asthma (P = 0.033), the effect being strongest for non-atopic asthmatics (P = 0.042). The MBL2 genotype had no clear effect on the occurrence of atopy in adults. In conclusion, our results abrogate the previously suggested predisposing effect of MBL insufficiency on atopy at least in adults. However, as MBL is a complement component participating in immune defence against microbes, and as in the pathogenesis of non-atopic asthma infectious agents are probably involved, the gene-environment interactions between MBL and infections should be assessed further with regard to asthma.
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Affiliation(s)
- J Aittoniemi
- Department of Clinical Microbiology, Centre for Laboratory Medicine, Pirkanmaa Hospital District, Tampere, Finland.
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Thórarinsdóttir HK, Lúdvíksson BR, Víkingsdóttir T, Leópoldsdóttir MO, Ardal B, Jónsson T, Valdimarsson H, Arason GJ. Childhood levels of immunoglobulins and mannan-binding lectin in relation to infections and allergy. Scand J Immunol 2005; 61:466-74. [PMID: 15882439 DOI: 10.1111/j.1365-3083.2005.01588.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Respiratory tract infections, allergies and otitis media are common problems in early childhood. Our aim was to evaluate in a longitudinal community-based cohort study the association between maturation of immunoglobulin (Ig) and mannan-binding lectin (MBL) responses and disease manifestations in the first 4 years of life. Sustained low levels of IgA proved the strongest single indicator of susceptibility for recurrent otitis media (P = 0.008) and respiratory tract infections (P = 0.02), and this condition was also associated with low production of IgG subclasses. About 7% of the cohort had sustained low levels of MBL (<0.4 mg/l). Low MBL did not predispose to any ailments studied, but children with low IgA and recurrent otitis media had relatively low MBL at birth, which failed to increase during the study period and was significantly reduced at the age of 4 years (P = 0.04). MBL levels increased from birth to 2 years (P < 0.0001) and were higher in children than in adults (P = 0.001). The increase was 1.9-fold in children with no recorded clinical events and 1.7-fold in children with asthma or infections, but significantly lower, 1.2-fold, in children with recurrent otitis media. Low levels of IgA within the normal range may reveal disease susceptibility not detected by conventional criteria. Slow maturation of Ig appears to be the main factor of susceptibility during childhood, but a strong corollary role for MBL is indicated by the high levels produced during childhood as well as the precipitation of disease in children with low levels of MBL and Ig.
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Affiliation(s)
- H K Thórarinsdóttir
- Department of Immunology, Institute for Medical Laboratory Sciences, Landspitali University Hospital, Hringbraut, Reykjavik, Iceland
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Abstract
Mannose-binding lectin (MBL) deficiency has now been recognised for 15 years. Numerous studies have shown that MBL deficiency is associated with an increased susceptibility to a range of infections. However, the importance of MBL, in defence against infection, is still debated. This article discusses recent developments in MBL research and explores how MBL may be operating in the setting of modern medical practice.
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Affiliation(s)
- N J Klein
- Infectious Diseases and Microbiology Unit, Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK.
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Abstract
Mannose-binding lectin (MBL) is a pattern recognition molecule of the innate immune system. It belongs to the collectin family of proteins in which lectin (carbohydrate-recognition) domains are found in association with collagenous structures. In man, these proteins include serum MBL, lung surfactant protein A (SP-A) and lung surfactant protein D (SP-D). MBL binds to a range of sugars including N-acetyl-D-glucosamine, mannose, N-acetyl-mannosamine, fucose and glucose. This permits the protein to interact with a wide selection of viruses, bacteria, yeasts, fungi and protozoa decorated with such sugars. Unlike the other collectins, MBL bound to microbial surfaces is able to activate the complement system in an antibody and C1-independent manner. This activation is mediated by complexes of MBL with a serine protease called MBL-associated serine protease 2 (MASP-2), which specifically cleaves C4 and C2 to create a C3 convertase enzyme. MBL may also interact directly with cell surface receptors and thereby promote opsonophagocytosis by a complement-independent pathway. It has been suggested that MBL plays an important role in the first hours/days of any primary immune response to a sugar decorated pathogen. This provides the host with a first-line of defence before the adaptive immune system becomes operative and in humans may be particularly important between 6 and 18 months of age when the adaptive system is still immature. MBL deficiency is one of the most common human immunodeficiencies and arises primarily from three single point mutations in exon 1 of the MBL-2 gene. These mutations result in a failure to assemble fully functional multimeric protein. Several studies have shown that deficiency of MBL increases the overall susceptibility of an individual to infectious disease. The most striking example of this is the association of acute respiratory tract infections with MBL deficiency in early childhood. In contrast, there is evidence that for some intracellular parasites MBL deficiency may be protective and this might explain the high frequency of MBL mutations in sub-Saharan Africa and South America. Increasingly, there is evidence that the association between MBL levels and disease is complex. For example, the protein appears to influence the severity of several diseases. The mechanism whereby MBL exerts such effects is unclear but one possibility is through a dose-dependent modulation of pro-inflammatory cytokines.
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Affiliation(s)
- M W Turner
- Immunobiology Unit, Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK.
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Abstract
There is an emerging interest for mannose-binding lectin (MBL) due to its role in innate immunity. In this survey we present a mixture of old and new data describing the effect MBL polymorphisms may have on the level and function of the molecule. Three single nucleotide substitutions in exon 1 of the mbl2 gene cause a dominant decrease of functional MBL in the circulation. Additionally, promoter variants influence expression of MBL. It has been assumed that the structural variant alleles may disrupt the assembly of MBL trimers or accelerate the degradation of the protein, thereby causing the decrease in MBL serum concentrations. We have analysed 1183 different sera in a double sandwich antibody ELISA using the same antibody to capture and detect MBL and find the same results as have been presented previously showing that different MBL promoter alleles have profound effect of on the MBL serum concentration. The use of a new anti-MBL monoclonal antibody, however, has shown that the amount of MBL in the circulation is less dependent on the presence of structural variant alleles than previously anticipated. Molecular characterisation of MBL revealed that sera from donors homozygous for the normal MBL genotype predominantly contained high molecular weight MBL, while sera from individuals heterozygous for the variant alleles contained both high and low molecular weight MBL. The ratio between high and low molecular weight MBL was dependent on the MBL promoter type on the normal haplotype. Sera deriving from individuals homozygous for MBL variant alleles contained mainly low molecular weight MBL. Of the different oligomers of MBL only the high molecular weight forms bound mannan efficiently and activated complement. In contrast to a previous notion, we demonstrate that variant alleles give rise to relatively high levels of MBL in the circulation. However, the variant MBL has lower molecular weight and is dysfunctional compared to normal MBL. The physiological relevance of variant MBL remains to be established.
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Affiliation(s)
- Peter Garred
- Department of Clinical Immunology, Tissue Typing Laboratory-7631, Rigshospitalet, Blegdamsvej 9, DK-2100 Copenhagen, Denmark.
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24
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Abstract
Mannan-binding lectin (MBL) is a plasma collectin (C-type lectin with a collagen-like domain) and is considered an important component of innate immunity. Circulating MBL is genetically determined for the major part, but plasma concentration is also markedly influenced by nongenetic factors. The carbohydrate-binding ability of MBL can be inhibited by simple sugars like mannose, fucose and N-acetylglucosamine, but its greatest avidity appears to be for repeating mannose-based structural patterns typical of microbial surfaces. By this means, MBL can bind to a wide variety of bacteria and other microbes, neutralizing them and/or opsonizing them by activating complement using the recently discovered lectin pathway of complement activation. Individual humans differ 1000-fold in MBL concentration, and individuals with low circulating MBL appear to be more vulnerable to infections in a number of clinical settings, especially when combined with secondary immune deficiency. The best evidence that MBL deficiency or insufficiency is physiologically relevant comes from a rapidly expanding literature of clinical studies. MBL insufficiency appears to be a significant risk factor for infections in infants, and for individuals of any age undergoing chemotherapy or post-transplant immunosuppression. Moreover, MBL appears to have a significant influence on the course of certain chronic diseases like rheumatoid arthritis and cystic fibrosis. Replacement therapy with a plasma-derived product is safe and seems promising, while recombinant MBL provides hope for large-scale therapeutic applications. Randomized clinical trials of MBL therapy, which are now on the horizon, should provide unambiguous evidence for the physiological significance of MBL in innate immunity.
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Affiliation(s)
- D C Kilpatrick
- SNBTS National Science Laboratory, Ellen's Glen Road, Edinburgh, EH17 7QT, UK.
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Kuipers S, Aerts PC, Sjöholm AG, Harmsen T, van Dijk H. A hemolytic assay for the estimation of functional mannose-binding lectin levels in human serum. J Immunol Methods 2002; 268:149-57. [PMID: 12215383 DOI: 10.1016/s0022-1759(02)00192-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A simple assay was developed to estimate functional mannose-binding lectin (MBL) levels in serum based on the principle of yeast-induced bystander lysis of chicken erythrocytes (ChE). The assay is sensitive to inhibition by ethylene glycol bis-(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA) (which allows alternative pathway activation), ethylene diamine tetraacetic acid (EDTA), mannose, N-acetylglucosamine and C1 esterase inhibitor (C1-INH), whereas it was not inhibited by galactose. A high-titer human anti-mannan antibody-containing serum with 0.06 microg MBL/ml gave a functional signal corresponding to 0.12 microg equivalents MBL/ml, indicating that anti-mannan antibodies are poorly hemolytic in the assay. The assay is well suited for the large-scale testing of patient samples for a functional MBL pathway of complement activation.
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Affiliation(s)
- Saskia Kuipers
- Eijkman-Winkler Center for Microbiology, Infectious Diseases, and Inflammation, University Medical Center Utrecht G04.614, Heidelberglaan 100, The Netherlands.
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26
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Affiliation(s)
- M J Walport
- Division of Medicine, Imperial College of Science, Technology and Medicine, London, United Kingdom.
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27
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Montalto MC, Collard CD, Buras JA, Reenstra WR, McClaine R, Gies DR, Rother RP, Stahl GL. A keratin peptide inhibits mannose-binding lectin. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 166:4148-53. [PMID: 11238665 DOI: 10.4049/jimmunol.166.6.4148] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Complement plays a significant role in mediating endothelial injury following oxidative stress. We have previously demonstrated that the lectin complement pathway (LCP), which is initiated by deposition of the mannose-binding lectin (MBL), is largely responsible for activating complement on endothelial cells following periods of oxidative stress. Identifying functional inhibitors that block MBL binding will be useful in characterizing the role of the LCP in disease models. The human cytokeratin peptide SFGSGFGGGY has been identified as a molecular mimic of N-acetyl-D-glucosamine (GlcNAc), a known ligand of MBL. Thus, we hypothesized that this peptide would specifically bind to MBL and functionally inhibit the LCP on endothelial cells following oxidative stress. Using a BIAcore 3000 optical biosensor, competition experiments were performed to demonstrate that the peptide SFGSGFGGGY inhibits binding of purified recombinant human MBL to GlcNAc in a concentration-dependent manner. Solution affinity data generated by BIAcore indicate this peptide binds to MBL with an affinity (K(D)) of 5 x 10(-5) mol/L. Pretreatment of human serum (30%) with the GlcNAc-mimicking peptide (10-50 microg/ml) significantly attenuated MBL and C3 deposition on human endothelial cells subjected to oxidative stress in a dose-dependent manner, as demonstrated by cell surface ELISA and confocal microscopy. Additionally, this decapeptide sequence attenuated complement-dependent VCAM-1 expression following oxidative stress. These data indicate that a short peptide sequence that mimics GlcNAc can specifically bind to MBL and functionally inhibit the proinflammatory action of the LCP on oxidatively stressed endothelial cells.
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Affiliation(s)
- M C Montalto
- Department of Anesthesiology, Perioperative and Pain Medicine, Center for Experimental Therapeutics and Reperfusion Injury, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
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28
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Selvaraj P, Narayanan PR, Reetha AM. Association of functional mutant homozygotes of the mannose binding protein gene with susceptibility to pulmonary tuberculosis in India. TUBERCLE AND LUNG DISEASE : THE OFFICIAL JOURNAL OF THE INTERNATIONAL UNION AGAINST TUBERCULOSIS AND LUNG DISEASE 2000; 79:221-7. [PMID: 10692990 DOI: 10.1054/tuld.1999.0204] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
SETTING Mannose binding protein gene polymorphism in pulmonary tuberculosis in India. OBJECTIVE To find out whether non-HLA genes such as mannose binding protein (MBP) genes are associated in the susceptibility to pulmonary tuberculosis. DESIGN Genotyping of MBP 52, 54 and 57 wild and mutant alleles was carried out in HLA-DR typed pulmonary tuberculosis patients (n = 202) and control subjects (n = 109). Since HLA-DR2 is associated with pulmonary-TB, the interaction of MBP genes on -DR2 and non-DR2 genes on the susceptibility was also studied. RESULTS A significantly increased genotype frequency of MBP functional mutant homozygotes (including 52, 54 and 57) was seen in pulmonary tuberculosis (PTB) patients (10.9%) than in control subjects (1.8%; P = 0.008; odds ratio: 6.5). Analysis of interaction of MBP genes and HLA-DR2 on the susceptibility to PTB revealed that these genes are associated with PTB independent of each other. CONCLUSION The present study shows that functional mutants of MBP are associated with PTB. Apart from HLA-DR2 association, association of non-HLA genes in the susceptibility to PTB is evident. This suggests that multigenetic factors (candidate genes) may be involved in the susceptibility/resistance to PTB.
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Affiliation(s)
- P Selvaraj
- Tuberculosis Research Centre (ICMR), Chennai, India. /
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29
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Laursen SB, Nielsen OL. Mannan-binding lectin (MBL) in chickens: molecular and functional aspects. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2000; 24:85-101. [PMID: 10717281 DOI: 10.1016/s0145-305x(99)00066-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Mannan-binding lectin (MBL) is a serum collectin (i.e. mosaic protein with collagenous and lectin domains) involved in the innate immune defence against various microbes. In vitro studies indicate that MBL exerts its function by binding to the microbial surface through its carbohydrate recognition domains followed by direct opsonization or complement activation via the MBL associated serine proteases MASP-1 and MASP-2. In Aves (i.e. chickens), as in man, only one MBL form has been found, while traditional laboratory animals (i.e. mouse and rat) have two MBL forms in serum. MBL has been extensively studied in mammals but recently also in Aves. This review summarizes the present knowledge of MBL in chickens and compares it to the situation in mammals.
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Affiliation(s)
- S B Laursen
- Department D., Odense University Hospital, DK-5000, Odense C, Denmark.
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30
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Srinivasan A, Ni Y, Tizard I. Specificity and prevalence of natural bovine antimannan antibodies. CLINICAL AND DIAGNOSTIC LABORATORY IMMUNOLOGY 1999; 6:946-52. [PMID: 10548591 PMCID: PMC95803 DOI: 10.1128/cdli.6.6.946-952.1999] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Immune responses to the carbohydrate components of microorganisms, mediated both by antibodies and by lectins, are an important part of host defense. In the present experiments, the specificity and presence of natural bovine antibodies against mannan, a common fungal antigen, were examined by enzyme-linked immunosorbent assay (ELISA), using Saccharomyces cerevisiae mannan as an antigen. The results showed that all serum samples from animals of three age groups (newborn, calf, and adult) tested contained antimannan antibodies, and the titer of these antibodies increased significantly in adults. However, titers among individual adult cattle differed widely. Inhibition assays showed that yeast mannan was the strongest inhibitor. D-Mannose exhibited only a minor inhibitory effect at high concentrations. This suggests that most of these antibodies recognize an oligosaccharide-based epitope(s) different from those recognized by lectins. Cattle possess three serum C-type lectins (collectins) capable of recognizing mannan in a calcium-dependent manner. Addition of EDTA to the reaction did not reduce antibody binding, suggesting that the binding of these antibodies to mannan was not affected by the presence of collectin. The antibodies purified from either calf or adult serum by mannan-Sepharose affinity chromatography consisted of mainly immunoglobulin G (IgG) and a smaller amount of IgM. IgG1 was shown to be the dominant antimannan IgG isotype by isotype-specific ELISA. Together, these results demonstrate the production of natural antimannan antibodies in cattle in an age-dependent manner. These antibodies might be involved in defending the host against mannan-containing pathogens as a specific line of defense in conjunction with the innate response by lectins.
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Affiliation(s)
- A Srinivasan
- Department of Veterinary Pathobiology, College of Veterinary Medicine, Texas A&M University, College Station, Texas 77843, USA
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31
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Nielsen OL, Jensenius JC, Jørgensen PH, Laursen SB. Serum levels of chicken mannan-binding lectin (MBL) during virus infections; indication that chicken MBL is an acute phase reactant. Vet Immunol Immunopathol 1999; 70:309-16. [PMID: 10507370 DOI: 10.1016/s0165-2427(99)00090-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Mannan-binding lectin (MBL) is a serum collectin which is believed to be an opsonin of the innate immune defence against various microorganisms. MBL is a minor acute phase reactant in man. We investigated the concentration of serum MBL in chickens infected with infectious bronchitis virus (IBV) and infectious laryngotracheitis virus (ILTV). The concentration of serum MBL increased about twofold (from approximately 6 to 12 microg/ml) due to these viral infections. The concentration peaked 3-7 days after infection with IBV, and 3-5 days after ILTV infection, depending on the ILTV strain used. The increased levels returned to normal values 6-10 days after infection. The results indicated that MBL is a minor acute phase reactant in chickens.
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32
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Gröndahl G, Johannisson A, Demmers S, Jensen Waern M. Influence of age and plasma treatment on neutrophil phagocytosis and CD18 expression in foals. Vet Microbiol 1999; 65:241-54. [PMID: 10189199 DOI: 10.1016/s0378-1135(98)00299-5] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The aim of this study was to evaluate the influence of age and plasma treatment on neutrophil phagocytosis, CD18 expression and serum opsonic capacity in foals in field settings. Microbial infections constitute a large threat in young foals and neutrophil functions are crucial for the defense. Blood samples were obtained from 13 foals at seven time points between the ages of 2 and 56 days and once from 16 adult horses. Six of the foals were treated with adult plasma at the age of 1 week. Neutrophil phagocytosis of yeast after various opsonizations and the expression of complement adhesion receptor CD18 were analysed by flow cytometry. Autologous serum opsonization resulted in 52+/-6.1% phagocytic neutrophils in 2-day-old foals (n = 12), a significantly lower rate than in adult horses (mean 84+/-3.1%; n = 16). In foals, yeast ingestion per neutrophil was also lower than in adults. Opsonic capacity increased with age (p < 0.05), reaching adult levels at 3-4 weeks. An increase in serum opsonic capacity followed plasma treatment (p < 0.05). The phagocytic capacity of foal neutrophils at the time-points studied was equal to or higher than that in the adults, when pooled adult horse serum or anti-yeast IgG was used as opsonin. In foals, serum IgG concentration was negatively correlated to serum opsonic capacity. CD18 receptor expression was higher in neutrophils from foals (<21 days old) than in those from adult horses (p < 0.05). The results indicate that foals are transiently deficient in serum opsonic capacity, which negatively affects their capacity for neutrophil phagocytosis. These changes in serum opsonins, unrelated to IgG, may be important factors in susceptibility to infections in foals.
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Affiliation(s)
- G Gröndahl
- Department of Large Animal Clinical Sciences, Faculty of Veterinary Medicine, Swedish University of Agricultural Sciences, Uppsala.
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33
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Valdimarsson H, Stefansson M, Vikingsdottir T, Arason GJ, Koch C, Thiel S, Jensenius JC. Reconstitution of opsonizing activity by infusion of mannan-binding lectin (MBL) to MBL-deficient humans. Scand J Immunol 1998; 48:116-23. [PMID: 9716101 DOI: 10.1046/j.1365-3083.1998.00396.x] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Mannan-binding lectin (MBL, previously named mannan-binding protein, MBP) is a serum collectin, which activates complement upon binding to microbial carbohydrates. This results in opsonization of the microorganisms as well as direct complement-mediated killing. Clinical evidence indicates that MBL has an important role in the innate immune defence against various pathogens. Genetically determined MBL deficiency is associated with increased susceptibility to infections. We have infused two MBL-deficient individuals with clinical grade MBL, purified from pooled donor plasma, in doses sufficient to attain normal concentration of MBL in serum. This resulted in normalization of complement-mediated opsonization. An initial rapid decrease in the serum concentration of MBL was followed by a slower decline with an estimated half-life of about 6 days. No adverse effects were observed and anti-MBL antibodies could not be detected following several MBL infusions. One of the two MBL recipient, a two-year-old girl, who had been suffering from repeated infections from the age of 4 months, was given a total of six MBL infusions. She has subsequently remained healthy for more than three years.
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Affiliation(s)
- H Valdimarsson
- Department of Immunology, University of Reykjavik, Iceland
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34
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Abstract
The collectins (collagenous lectins) constitute a major element of the innate immune system and mannan-binding lectin (or mannose-binding lectin, MBL) is now recognized as a serum constituent with many of the attributes of both antibody and C1q. A common opsonic deficiency recognized more than 20 years ago is known to be a functional manifestation of MBL deficiency. This is largely explained by three single point mutations in exon 1 of the MBL gene, each of which disrupts the collagenous region and probably prevents assembly of higher order oligomers. Several independent studies suggest that deficiency of the protein increases significantly the risk of infection with a range of different pathogens and also predisposes such individuals to autoimmune disease. The first description of MBL replacement therapy [Valdimarsson et al., Scand J Immunol 1998;48:116-123] provides evidence that administration of this purified plasma protein is safe, practical and possibly efficacious. These preliminary observations in two recipients now need to be extended in large-scale trials.
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Affiliation(s)
- M W Turner
- Immunobiology Unit, Institute of Child Health, University College London Medical School, UK
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35
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Abstract
The immune system consists of various types of cells and molecules that specifically interact with each other to initiate the host defense mechanism. Recent studies have shown that carbohydrates and lectins (carbohydrate-binding proteins) play an essential role in mediating such interactions. Both lectins and carbohydrates are widely distributed in the mammalian tissues as well as in microorganisms. Carbohydrates, due to their chemical nature, can potentially form structures that are more variable than proteins and nucleic acids. Lectins can exist in either soluble or cell-associated form, and although overall structures vary, invariably possess carbohydrate-recognition domains (CRD) with various specificities. The interaction between lectins and carbohydrates have been shown to be involved in such activities as opsonization of microorganisms, phagocytosis, cell adhesion and migration, cell activation and differentiation, and apoptosis. The number of lectins identified in the immune system is increasing at a rapid pace. The development in this area has opened a new aspect in studying the immune system, and at the same time, provided new therapeutic routes for the treatment and prevention of disease.
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Affiliation(s)
- Y Ni
- Glycobiology Laboratory, Carrington Laboratories Inc., College Station, TX 77845, USA
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36
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37
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Aittoniemi J, Miettinen A, Laippala P, Isolauri E, Viikari J, Ruuska T, Soppi E. Age-dependent variation in the serum concentration of mannan-binding protein. Acta Paediatr 1996; 85:906-9. [PMID: 8863868 DOI: 10.1111/j.1651-2227.1996.tb14182.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Mannan-binding protein (MBP) is an acute phase reactant, and its deficiency is associated with the common opsonic defect and suspectibility to infections and atopic constitution. The aim of this study was to investigate the changes occurring in the serum level of MBP in infancy and during later childhood. We studied the serum concentration of MBP in 611 Finnish children of different ages and 110 adults by using an enzyme immunoassay. In an analysis of successive serum samples from infants at the day of birth and at the ages of 1 and 5 months, and at 1 and 2 years, the serum concentration of MBP increased significantly after birth, and was at its highest (the mean and median were 8.13 and 8.49 mgl-1, respectively) at the age of 1 month. After that, it declined to the initial level until the age of 5 months. The MBP concentration continued to decrease during childhood, and after the age of 12 years the MBP values reached the adult level. In Finnish adults the mean and median concentrations of MBP were 4.48 and 4.02 mgl-1, respectively, which seem to be higher than those reported previously in other populations. The high concentration of MBP in infants may best be explained by exposure to novel environmental antigens in early childhood, which suggests a protective role for MBP during the period of immaturity of the immunosystem. In older children the high level of MBP can probably be explained by childhood infections and the ensuing need of MBP.
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Affiliation(s)
- J Aittoniemi
- Department of Clinical Microbiology, Tampere University Hospital, Finland
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38
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Affiliation(s)
- M W Turner
- Molecular Immunology Unit, University of London
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39
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Summerfield JA, Ryder S, Sumiya M, Thursz M, Gorchein A, Monteil MA, Turner MW. Mannose binding protein gene mutations associated with unusual and severe infections in adults. Lancet 1995; 345:886-9. [PMID: 7707811 DOI: 10.1016/s0140-6736(95)90009-8] [Citation(s) in RCA: 263] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
A defect in opsonisation can cause a common immunodeficiency. A mutation in mannose binding protein (MBP) caused by point mutations in the MBP gene will lead to such a defect. This type of syndrome can cause recurrent infections in infants between 6 and 18 months of age but is not generally believed to predispose to adult infections. We looked at 4 patients with severe and unusual infections in whom MBP gene mutations were the only identified cause of immunodeficiency and one patient with combined MBP and IgA deficiency. We analysed the MBP genotypes of all the patients in whom we suspected an immunodeficiency because of their clinical history. Infections seen were recurrent skin abscesses, chronic cryptosporidial diarrhoea, meningococcal meningitis with recurrent herpes simplex, and fatal klebsiella lobar pneumonia. Both sexes were affected and ages ranged from 15 to 56 years. Two patients were homozygous for codon 54 mutations, one patient had codon 52 and codon 54 mutations and was phenotypically homozygous, and two patients were heterozygous for codon 54 mutations. Individuals homozygous for MBP mutations are unusual in the general population (approximate frequency 0.3%). The occurrence of three homozygotes for MBP mutations among these five infected patients suggests that MBP deficiency may confer a life-long risk of infection.
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Affiliation(s)
- J A Summerfield
- Department of Medicine, St Mary's Hospital Medical School, Imperial College of Science, Technology and Medicine, London
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40
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Thiel S, Bjerke T, Hansen D, Poulsen LK, Schiøtz PO, Jensenius JC. Ontogeny of human mannan-binding protein, a lectin of the innate immune system. Pediatr Allergy Immunol 1995; 6:20-3. [PMID: 7550760 DOI: 10.1111/j.1399-3038.1995.tb00252.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Mannan-binding protein (MBP) is a member of the collectins. These lectins are composed of polypeptide chains which contains a collagen-like region and a calcium dependent carbohydrate recognition domain (named a C-type CRD). MBP binds via the CRD to carbohydrate structures on microorganisms. MBP can activate the complement system when bound to carbohydrate. MBP is thus thought to play a role in the defence against microorganisms. The present report describes the ontogeny of MBP. The level of MBP increase during the first 3 months of life, at which time a stable level is reached, comparable to that seen in adults. On average, the level of MBP at term was 37% of the post 3-month level. Measurements on infants born prematurely showed a 3-fold increase in MBP concentration from the time of birth at around 30 weeks from conception to the 10th week of life.
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Affiliation(s)
- S Thiel
- Institute of Medical Microbiology, University of Aarhus, Denmark
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41
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Reid KB, Turner MW. Mammalian lectins in activation and clearance mechanisms involving the complement system. SPRINGER SEMINARS IN IMMUNOPATHOLOGY 1994; 15:307-26. [PMID: 8153870 DOI: 10.1007/bf01837363] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
CRP and the mammalian lectins containing collagen-like structure (collectins) can clearly participate in a variety of antibody-independent recognition and clearance mechanisms which result in the neutralisation and elimination of pathogenic organisms (Fig. 2). Only CRP and MBP appear to have the capacity to activate complement, and while all the collectins (MBP, SP-A, SP-D and conglutinin) can utilise the C1q receptor, only conglutinin shows specificity for iC3b. The C-type lectin domains in the globular heads of the collectins have the capacity to recognise a range of specific carbohydrate structures which are found on the surfaces of pathogens commonly associated with infections in blood, lung and amniotic fluids. The proposed presentation of the carbohydrate-collectin complex to C1q receptors, via the collagen-like regions in the collectins is an attractive hypothesis for the triggering of protective mechanisms and there are already a number of publications which support this view. However, the precise manner by which these collagen 'stalks' interact with the C1q receptor and the complete characterisation of the receptor on a variety of different cell types remains to be elucidated. Similarly, whether or not there is a role for any of these lectins in autoimmunity/immunopathology has not, as yet, been addressed.
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Affiliation(s)
- K B Reid
- Department of Biochemistry, University of Oxford, UK
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42
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Mathur NB, Subramanian BK, Sharma VK, Puri RK. Exchange transfusion in neutropenic septicemic neonates: effect on granulocyte functions. Acta Paediatr 1993; 82:939-43. [PMID: 8111174 DOI: 10.1111/j.1651-2227.1993.tb12604.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Depletion neutropenia caused by overwhelming bacterial infection is associated with fatal outcome and is an objective indicator of the severity of sepsis. Studies on controlled evaluation of exchange transfusion in the management of severe neonatal sepsis have not considered neutropenia as an inclusion criterion, and randomized, controlled trials on evaluation of neutrophil functions after exchange transfusion are scarce. This prompted us to carry out the present study. Septicemic neonates were enrolled if they had neutropenia and were randomized to undergo exchange transfusion (study group, n = 20) or not (controls, n = 10). Granulocyte functions were assessed using the nitro blue tetrazolium (NBT) reduction test and the staphylococcidal index. Blood was drawn for granulocyte function tests once from controls and donors, and before, immediately after and 6 h after exchange transfusion in the study group. Mortality was 35% in the study group and 70% in controls. Gram-negative organisms accounted for 80% in the study group and 90% in controls. Mean total leukocyte count and neutrophil count increased significantly immediately after exchange transfusion and 6 h later. Absolute band count decreased significantly immediately after exchange transfusion and increased 6 h later. NBT reduction in septicemic neonates in the study group, as well as in controls, was significantly decreased as compared to donor cells. NBT reduction improved significantly immediately after exchange transfusion and 6 h later. The values of the percentage of viable staphylococci recovered from neutrophils also improved significantly immediately after exchange transfusion and 6 h later.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- N B Mathur
- Department of Pediatrics, Maulana Azad Medical College, New Delhi, India
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43
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Thiel S, Holmskov U, Hviid L, Laursen SB, Jensenius JC. The concentration of the C-type lectin, mannan-binding protein, in human plasma increases during an acute phase response. Clin Exp Immunol 1992; 90:31-5. [PMID: 1395098 PMCID: PMC1554537 DOI: 10.1111/j.1365-2249.1992.tb05827.x] [Citation(s) in RCA: 206] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Two ELISAs for estimating mannan-binding protein (MBP) were constructed and the concentration of MBP in plasma was followed in patients undergoing major surgery and in patients having a malarial attack. In both cases increases of MBP in the plasma were observed. The relative increase and the kinetics varied from person to person. The concentration of MBP increased between 1.5- and three-fold following surgery. In some patients an increase was seen at day 1 whereas in others the increase was not observed until days 3-9. In the malaria patients an increased level of MBP was maintained during 30 days of treatment with chloroquine. The relative increase in MBP was independent of the presurgery or premalaria levels.
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Affiliation(s)
- S Thiel
- Institute for Medical Microbiology, Aarhus University, Denmark
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44
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Abstract
Mannan-binding protein is an animal serum lectin (i.e. a molecule with the ability to bind specifically to certain carbohydrate structures). The relevant carbohydrate ligands are found on many pathogenic microorganisms. After binding to suitable carbohydrate ligands, mannan-binding protein is found to be an activator of the classical pathway of complement via an activation of the C1r2C1s2 complex, i.e. antibody and C1q independent. The molecular organization of MBP resembles that of C1q with a distinct division of collagen-like and globular amino acid sequences. This molecular similarity seems to be the basis for the common functional activity of the two proteins. MBP may play an important protective role, especially at early stages of infection prior to the generation of the specific humoral and cellular defence system. The paper explores the structure and the physiological functions of mannan-binding protein.
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Affiliation(s)
- S Thiel
- Institute of Medical Microbiology, Aarhus University, Denmark
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45
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Lipscombe RJ, Lau YL, Levinsky RJ, Sumiya M, Summerfield JA, Turner MW. Identical point mutation leading to low levels of mannose binding protein and poor C3b mediated opsonisation in Chinese and Caucasian populations. Immunol Lett 1992; 32:253-7. [PMID: 1500095 DOI: 10.1016/0165-2478(92)90058-v] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A common opsonic defect occurring in 7% of the Caucasian population is associated with low serum levels of the lectin mannose binding protein (MBP). This study sought to determine whether the deficiency was also present in a Chinese population using sera obtained from 100 healthy Chinese children (age range 6 weeks-16 years). The distribution profiles of MBP levels and C3b/C3bi fragments binding to mannan coated plates were both bimodal and similar to the corresponding Caucasian profiles. Serum MBP levels were low in 9% of the Chinese children and all of these sera generated low levels of C3b/C3bi fragments. Overall there was a high significant correlation between MBP levels and C3b opsonin generation (r = 0.77; P less than 0.001). By analogy with similar findings in a Caucasian population we believe this correlation to be a reflection of antibody independent complement activation by MBP. In a pilot study of DNA obtained from three adult Chinese with low MBP levels the point mutation causing MBP deficiency in Caucasians was identified in all three cases.
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46
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Shield JP, Judge MR, Reardon W, Baraitser M, Nohria M, Malone M, Harper JI. Lethal congenital erythroderma: a newly recognised genetic disorder. Clin Genet 1992; 41:273-7. [PMID: 1535034 DOI: 10.1111/j.1399-0004.1992.tb03681.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We report 4 patients and their extended families comprising 17 cases, all of whom had congenital exfoliative erythroderma resistant to treatment, associated with failure to thrive and hypoalbuminaemia. All died in the first year of life. This condition appears to be inherited in an autosomal recessive manner and the underlying defect remains unknown.
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Affiliation(s)
- J P Shield
- Department of Dermatology, Hospitals for Sick Children, London, UK
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47
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Summerfield JA. The role of human lectins in host defence. The Linacre Lecture 1991. JOURNAL OF THE ROYAL COLLEGE OF PHYSICIANS OF LONDON 1992; 26:92-6. [PMID: 1573596 PMCID: PMC5375413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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48
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Affiliation(s)
- M W Turner
- Molecular Immunology Unit, Institute of Child Health, London
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49
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Pupo RA, Tyring SK, Raimer SS, Wirt DP, Brooks EG, Goldblum RM. Omenn's syndrome and related combined immunodeficiency syndromes: diagnostic considerations in infants with persistent erythroderma and failure to thrive. J Am Acad Dermatol 1991; 25:442-6. [PMID: 1832695 DOI: 10.1016/0190-9622(91)70225-q] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A 4-month-old male infant had a 2-month history of an exfoliative erythroderma and alopecia. Recurrent mucosal infections, diffuse lymphadenopathy, hepatosplenomegaly, lymphocytosis and eosinophilia, anemia, and failure to thrive later developed. Investigation revealed a combined immunodeficiency with T cells of an unusual phenotype in his peripheral blood, skin, and lymph nodes. Our patient's clinical manifestations most closely resemble Omenn's syndrome, a rare form of autosomal recessive combined immunodeficiency.
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Affiliation(s)
- R A Pupo
- Department of Dermatology, University of Texas Medical Branch, Galveston 77550
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50
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Judge MR, Shield JP, Cant A, Strobel S, Levin M, Reiser J, Harper JI. Erythroderma, palmoplantar keratoderma and profound failure to thrive in an infant. Br J Dermatol 1991; 124:606-8. [PMID: 1829626 DOI: 10.1111/j.1365-2133.1991.tb04960.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The case is reported of a female infant, who at the age of 3 months developed severe erythroderma, marked hyperkeratosis of the palms and soles and subsequently extreme growth failure and intermittent diarrhoea. Her course was complicated by life-threatening infections but detailed investigation revealed no recognized underlying metabolic or immune abnormality.
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Affiliation(s)
- M R Judge
- Department of Dermatology, Hospitals for Sick Children, London, U.K
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