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Picture from www.blog.bryanmjones.com, access November 2015
Biology of Basophils &
Basophil Activation Test
Suda Sibunruan...
Outline
• Development and morphology
• Functional and Phenotypic Markers
• Mediators and effector functions
• Role in heal...
Pictures from www.nobelprize.org &
http://intranet.tdmu.edu.ua,
access November 2015
Paul Ehrlich (1854-1915)
1879
Identif...
Access from www.commons.wikimedia.org, November 2015
Schroeder JT. Immunological Reviews 2011;242:144–60
Schroeder JT. Middleton’s Allergy Principle and Practice. 8th edition,...
Siracusa MC. et. al. J Allergy Clin Immunol 2013;132:789-801
Siracusa MC. et. al. J Allergy Clin Immunol 2013;132:789-801
Picture from http://static.wikidoc.org &
Siracusa MC. et. al. Immunology and Cell Biology 2010;88:275–84
CD34+ myeloid
hem...
Schroeder JT. Middleton’s Allergy Principle and Practice. 8th edition, 2014
Stone KD., et. al. J Allergy Clin Immunol 2010;125:S73-80
Schroeder JT. Middleton’s Allergy Principle and Practice. 8th ed...
Access from www.en.wikipedia.org & www.commons.wikimedia.org, November 2015
Morphology
Schroeder JT. Immunological Reviews 2011;242:144–60
Stone KD., et. al. J Allergy Clin Immunol 2010;125:S73-80
Kawakami T. and Galli SJ. Nature Reviews Immunology 2002;2:773-8...
Siracusa MC. et. al. Immunology and Cell Biology 2010;88:275–84
Functional and Phenotypic Markers
Siracusa MC. et. al. Immunology and Cell Biology 2010;88:275–84
• Immunoglobulin Fc receptors
FcεRI, FcγRIIb
• Cytokine re...
Basophil Activation
• Immunoglobulin E dependent pathway
• Immunoglobulin E independent pathway
Karasuyama H. et. al. Nature Reviews Immunology 2009;9:9-13
Schroeder JT. Middleton’s Allergy Principle and Practice. 8th ...
Moon TC. et. al. Front Immunol 2014;5:1-18
Spencer LA. et. al. Front Immunol 2014;5:496
IgE dependent pathway
Mast cell
Pi...
Cromheecke JL. et. al. Curr Allergy Asthma Rep 2014;14:408
Hausmann OV. et. al. Immunol Allergy Clin N Am 2009;29:555–66
B...
Siracusa MC. et. al. Immunology and Cell Biology 2010;88:275–84
Mediators
- Preformed mediators
- Newly syn. Leukotrienes ...
Schroeder JT. Middleton’s Allergy Principle and Practice. 8th edition, 2014
Schroeder JT. Middleton’s Allergy Principle and Practice. 8th edition, 2014
Basophils play a dual role in allergic inflamm...
Cromheecke JL. et. al. Curr Allergy Asthma Rep 2014;14:408
IgE dependent & independent pathway
Marone G. et. al. Trends Immunol 2001;22:229-32
Shed- or virus-bound-gp120 can interact with variable,
heavy chain 3 (VH3)...
Schroeder JT. Adv Immunol 2009;101:123-61
Cromheecke JL. et. al. Curr Allergy Asthma Rep 2014;14:408
Activation of TLR 2 a...
Chen K. and Cerutti A. Current Opinion in Immunology 2011;23:345–52
IgD immune complexes
Augment mucosal immune responses ...
Cromheecke JL. et. al. Curr Allergy Asthma Rep 2014;14:408
Basophil degranulation is restricted to signals induced
by FcεR...
Siracusa MC. et. al. J Allergy Clin Immunol 2013;132:789-801
Granzyme B, a novel mediator of allergic inflammation:
its induction and release in blood basophils and human asthma
Tscho...
Schroeder JT. Adv Immunol 2009;101:123-61
Only cytokines reported to negatively regulate basophils are
type 1 interferons ...
Abbas AK, et al. Cellular and Molecular immunology 2014 Eighth Edition
Abbas AK, et al. Cellular and Molecular immunology 2014 Eighth Edition
Picture from http://what-when-how.com, access November 2015
Cromheecke JL. et. al. Curr Allergy Asthma Rep 2014;14:408
Naclerio RM, et al. N Engl J Med 1985;313:65-70
Inflammatory mediators in late antigen-induced rhinitis
Obj: To investigat...
Kepley CL, et. al. Am J Resp Crit Care Med 2011;164:1053-8
Cromheecke JL. et. al. Curr Allergy Asthma Rep 2014;14:408
Cont...
Dvorak HF, et al. J Exp Med 1970;132:558-82
Schroeder JT. Middleton’s Allergy Principle and Practice. 8th edition, 2014
Pi...
Siracusa MC. et. al. Immunology and Cell Biology 2010;88:275–84
Basophils in immune regulation
Interact with T or B cell
Karasuyama H. et. al. Nature Reviews Immunology 2009;9:9-13
Sokol CL, Medzhitov R. Mucosal Immunol 2010;3:129-37
Basophils...
Voehringer D. Trends Parasitol 2009;25:551-6
Gibbs BF. Clin Exp Med 2005;5:43–9
Siracusa MC. et. al. J Allergy Clin Immunol 2013;132:789-801
Role in health and diseases
Karasuyama H. et. al. Nature Reviews Immunology 2009;9:9-13
Roles of basophils in allergy
1) In sensitized animals, specif...
Role of basophils in allergic diseases
Important in many if not all allergic diseases:
• Anaphylaxis
• Allergic rhinitis
•...
Role of basophils in other clinical conditions
• Infections
• Autoimmunity
• Malignancy
Cromheecke JL. et. al. Curr Allerg...
http://www.dailymail.co.uk/sciencetech/article-2957265/When-white-blood-cells-ATTACK-Amazing-video-captures-moment-immune-...
Voehringer D. Trends Parasitol 2009;25:551-6
Schroeder JT. Middleton’s Allergy Principle and Practice. 8th edition, 2014
L...
Role of basophils in other clinical conditions
• Infections
• Autoimmunity
• Malignancy
Cromheecke JL. et. al. Curr Allerg...
Charles N and Rivera J. Curr Allergy Asthma Rep 2011;11:378–87
Cromheecke JL. et. al. Curr Allergy Asthma Rep 2014;14:408
...
Schuerwegh JM, et al. PNAS. 2010;107:2586–91
Cromheecke JL. et. al. Curr Allergy Asthma Rep 2014;14:408
Rheumatoid arthrit...
Cromheecke JL. et. al. Curr Allergy Asthma Rep 2014;14:408
Stone KD., et. al. J Allergy Clin Immunol 2010;125:S73-80
Kawak...
Role of basophils in other clinical conditions
• Infections
• Autoimmunity
• Malignancy
Cromheecke JL. et. al. Curr Allerg...
Wimazal F. et. al. Cancer 2010;116:2372-81
Cromheecke JL. et. al. Curr Allergy Asthma Rep 2014;14:408
Retrospective study ...
Nievergall E. et. al. Blood 2014;123:1218-28
Hoffmann HJ. et. al. Allergy 2015;70:1393-405
Karasuyama H. et. al. Nature Reviews Immunology 2009;9:9-13
measures basophi...
Diagnostic evaluation
Determine clinically relevant allergen in addition
to clinical history, skin prick test, and specifi...
Hoffmann HJ. et. al. Allergy 2015;70:1393-405
Sensitivity & specificity
• Drug allergy: Beta-lactams, Neuromuscular blocking
agent (NMBA), quinolones , radio contrast m...
Monitor patients
• Allergen immunotherapy
• Anti-IgE treatment
• Natural resolution of allergy
Hoffmann HJ. et. al. Allerg...
Hoffmann HJ. et. al. Allergy 2015;70:1393-405
Basophil reactivity is the dose (range) at which maximal response occurs
Bas...
Hoffmann HJ. et. al. Allergy 2015;70:1393-405
Basophil reactivity reflected severity
Basophil sensitivity reflected thresh...
Hoffmann HJ. et. al. Allergy 2015;70:1393-405
Advantages
• Fewer resources
• More reproducible than challenge test
• Less stressful for the patient
• Avoids severe alle...
Nonresponders
• 6–17% of population
• Nonresponders can experience allergic
symptoms and have positive SPT with relevant
a...
Kepley CL, et. al. J Allergy Clin Immunol 1999;104:279-84
Differences in intracellular signaling pathway
Considerations when taking a blood
sample for BAT (1)
• Remember to…
Check absolute basophil counts of above
50 cells/µl w...
Considerations when taking a blood
sample for BAT (2)
• Antihistamines do not influence BAT but
systemic steroids and cycl...
Considerations when taking a blood
sample for BAT (3)
• Basophil function is mostly assessed in
heparin-stabilized blood
H...
Hoffmann HJ. et. al. Allergy 2015;70:1393-405
Allergen concentration range
Benzylpenicillin 2 &0.4 mg/ml
Amoxicillin 1.25 & 0.25 mg/ml
PPL 0.25 & 0.05 mg/ml
MDM 0.25 & ...
Summary (1)
• Basophils have long been seen as a surrogate
with which to study the more elusive mast
cell. This view, howe...
Summary (2)
• Once thought to do little other than to secrete
histamine and LTC4, basophils are now well
recognized to be ...
Summary (3)
• This information, along with evidence that
these cells infiltrate allergic lesions and are
capable of respon...
Thank you for your attention
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Biology of basophils & basophil activation test

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Biology of basophils & basophil activation test

Presented by Suda Sibunrueng, MD.

December4, 2015

Published in: Health & Medicine
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Biology of basophils & basophil activation test

  1. 1. Picture from www.blog.bryanmjones.com, access November 2015 Biology of Basophils & Basophil Activation Test Suda Sibunruang, M.D.
  2. 2. Outline • Development and morphology • Functional and Phenotypic Markers • Mediators and effector functions • Role in health and diseases • Basophil activation test
  3. 3. Pictures from www.nobelprize.org & http://intranet.tdmu.edu.ua, access November 2015 Paul Ehrlich (1854-1915) 1879 Identified by staining with basic dyes
  4. 4. Access from www.commons.wikimedia.org, November 2015
  5. 5. Schroeder JT. Immunological Reviews 2011;242:144–60 Schroeder JT. Middleton’s Allergy Principle and Practice. 8th edition, 2014 IL-3 affects essentially every aspect of basophil biology including development and maturation, survival, acute or late effects on mediator release, and direct stimulation of IL-13 production
  6. 6. Siracusa MC. et. al. J Allergy Clin Immunol 2013;132:789-801
  7. 7. Siracusa MC. et. al. J Allergy Clin Immunol 2013;132:789-801
  8. 8. Picture from http://static.wikidoc.org & Siracusa MC. et. al. Immunology and Cell Biology 2010;88:275–84 CD34+ myeloid hematopoietic progenitors IL - 3 IL – 5 IL-3, GM-CSF SCF
  9. 9. Schroeder JT. Middleton’s Allergy Principle and Practice. 8th edition, 2014
  10. 10. Stone KD., et. al. J Allergy Clin Immunol 2010;125:S73-80 Schroeder JT. Middleton’s Allergy Principle and Practice. 8th edition, 2014 Picture from http://hdimagelib.com, access November 2015 Storage granule contents • Major preformed mediator is histamine • Histamine complexes with proteoglycans, most notably chondroitin sulfate, as opposed to heparin sulfate in the mast cell, and dissociates after exocytosis by ion exchange and changes in pH • Contain less heparin than mast cell • Tryptase in basophil are thought to be much lower than in mast cells; however, there can be variability Clearly caution in using tryptase as the sole specific marker for identifying the presence of mast cells
  11. 11. Access from www.en.wikipedia.org & www.commons.wikimedia.org, November 2015 Morphology
  12. 12. Schroeder JT. Immunological Reviews 2011;242:144–60
  13. 13. Stone KD., et. al. J Allergy Clin Immunol 2010;125:S73-80 Kawakami T. and Galli SJ. Nature Reviews Immunology 2002;2:773-86 Differ more than alike Basophils • Segmented nucleus • Larger & fewer granules Mast cell Basophil
  14. 14. Siracusa MC. et. al. Immunology and Cell Biology 2010;88:275–84 Functional and Phenotypic Markers
  15. 15. Siracusa MC. et. al. Immunology and Cell Biology 2010;88:275–84 • Immunoglobulin Fc receptors FcεRI, FcγRIIb • Cytokine receptors IL-3R,IL-5R, GM-CSFR • Chemokine receptors CCR2, CCR3 • Complement receptors CD11b, CD11c, CD35, CD88 • PG receptors CRTH2 • TLRs
  16. 16. Basophil Activation • Immunoglobulin E dependent pathway • Immunoglobulin E independent pathway
  17. 17. Karasuyama H. et. al. Nature Reviews Immunology 2009;9:9-13 Schroeder JT. Middleton’s Allergy Principle and Practice. 8th edition, 2014 Human basophils may express between 5,000 and 1 million FcεRI sites per cell Estimated 200 IgE-receptor cross-links needed to initiate mediator release from basophils Immunoglobulin E dependent pathway
  18. 18. Moon TC. et. al. Front Immunol 2014;5:1-18 Spencer LA. et. al. Front Immunol 2014;5:496 IgE dependent pathway Mast cell Piecemeal degranulation: vesicular transport of small packets of materials from secretory granules to cell surface
  19. 19. Cromheecke JL. et. al. Curr Allergy Asthma Rep 2014;14:408 Hausmann OV. et. al. Immunol Allergy Clin N Am 2009;29:555–66 Basophil activation markers: CD63 & CD203c glycoprotein expressed in membranes of cytoplasmic granules CD203c is a glycosylated transmembrane molecule Basophils express low level of CD203c, which is increased with basophil activation and may correspond to piecemeal degranulation
  20. 20. Siracusa MC. et. al. Immunology and Cell Biology 2010;88:275–84 Mediators - Preformed mediators - Newly syn. Leukotrienes & prostaglandins - Cytokines & chemokines Significant source of IL-4 and IL-13 vital to pathogenesis of allergic disease
  21. 21. Schroeder JT. Middleton’s Allergy Principle and Practice. 8th edition, 2014
  22. 22. Schroeder JT. Middleton’s Allergy Principle and Practice. 8th edition, 2014 Basophils play a dual role in allergic inflammation, depending on antigen concentrations: At low concentrations of antigen, basophils may modulate immune responses of B cells, T cells, and eosinophils through production of IL-4 and IL-13 As they infiltrate lesion site, and concentration of antigen increases, basophils may take on more of an effector role by secreting two substances (i.e., histamine and LTC4)
  23. 23. Cromheecke JL. et. al. Curr Allergy Asthma Rep 2014;14:408 IgE dependent & independent pathway
  24. 24. Marone G. et. al. Trends Immunol 2001;22:229-32 Shed- or virus-bound-gp120 can interact with variable, heavy chain 3 (VH3)+ IgE bound to FcεRI+ cells of individuals at an early stage of infection Induces IL-4 and IL-13 release and favours a shift towards a Th2 phenotype HIV-1 transactivation (Tat) protein secreted by infected cells interacts with CCR3 receptor and is a potent chemoattractant Extracellular Tat can also induce IL-4 and IL-13 release Human FcεRI+ cells express CCR3 and CXCR4, which are co-receptors for several strains of HIV-1, suggesting that these cells could be infected by certain strains of HIV-1 High IgE levels often observed in some HIV-infected patients
  25. 25. Schroeder JT. Adv Immunol 2009;101:123-61 Cromheecke JL. et. al. Curr Allergy Asthma Rep 2014;14:408 Activation of TLR 2 and 4 can lead to production of BAFF and IL-13, indicating that microbiota might modulate immunity by interacting with basophils
  26. 26. Chen K. and Cerutti A. Current Opinion in Immunology 2011;23:345–52 IgD immune complexes Augment mucosal immune responses by promoting B and T cell activation, leukocyte recruitment and direct microbial killing
  27. 27. Cromheecke JL. et. al. Curr Allergy Asthma Rep 2014;14:408 Basophil degranulation is restricted to signals induced by FcεRI crosslinking, C5a, and IL-3
  28. 28. Siracusa MC. et. al. J Allergy Clin Immunol 2013;132:789-801
  29. 29. Granzyme B, a novel mediator of allergic inflammation: its induction and release in blood basophils and human asthma Tschopp CM, et al. Blood 2006;108:2290-9 Schroeder JT. Middleton’s Allergy Principle and Practice. 8th edition, 2014 Basophils synthesize and release granzyme B in response to IL-3 stimulation The significance of this finding remains undetermined
  30. 30. Schroeder JT. Adv Immunol 2009;101:123-61 Only cytokines reported to negatively regulate basophils are type 1 interferons which limit IL-3-induced cytokine production
  31. 31. Abbas AK, et al. Cellular and Molecular immunology 2014 Eighth Edition
  32. 32. Abbas AK, et al. Cellular and Molecular immunology 2014 Eighth Edition
  33. 33. Picture from http://what-when-how.com, access November 2015
  34. 34. Cromheecke JL. et. al. Curr Allergy Asthma Rep 2014;14:408
  35. 35. Naclerio RM, et al. N Engl J Med 1985;313:65-70 Inflammatory mediators in late antigen-induced rhinitis Obj: To investigate mechanisms responsible for late-phase response in patients with allergies Method: We measured four biochemical mediators (histamine, tosyl-L-arginine methyl ester [TAME]-esterase, kinin, and prostaglandin D2) in nasal secretions after nasal challenge with pollen antigen in 12 patients with allergy and 3 persons for control
  36. 36. Kepley CL, et. al. Am J Resp Crit Care Med 2011;164:1053-8 Cromheecke JL. et. al. Curr Allergy Asthma Rep 2014;14:408 Contribution of basophils to LPR is based on their presence in tissues within hours following experimental allergen challenge Late response is largely mediated by basophils Immunohistochemical Detection of Human Basophils in Postmortem Cases of Fatal Asthma
  37. 37. Dvorak HF, et al. J Exp Med 1970;132:558-82 Schroeder JT. Middleton’s Allergy Principle and Practice. 8th edition, 2014 Picture from www.twineagles.org, access November 2015 Delayed-type hypersensitivity When given rhus toxoid (the active agent in poison ivy) or dinitrochlorobenzene in a patch test, sensitized subjects developed skin reactions that were characterized by a cellular infiltrate into dermis consisting of up to approximately 16% basophils by 3 - 6 days after application of antigen
  38. 38. Siracusa MC. et. al. Immunology and Cell Biology 2010;88:275–84 Basophils in immune regulation Interact with T or B cell
  39. 39. Karasuyama H. et. al. Nature Reviews Immunology 2009;9:9-13 Sokol CL, Medzhitov R. Mucosal Immunol 2010;3:129-37 Basophils secrete IL-4 & TSLP, which induce differentiation of naive T cells into TH2 cells in cooperation with dendritic cells TSLP is capable of inhibiting IL-12 production by DCs, thereby further promoting Th2 cell differentiation
  40. 40. Voehringer D. Trends Parasitol 2009;25:551-6
  41. 41. Gibbs BF. Clin Exp Med 2005;5:43–9
  42. 42. Siracusa MC. et. al. J Allergy Clin Immunol 2013;132:789-801 Role in health and diseases
  43. 43. Karasuyama H. et. al. Nature Reviews Immunology 2009;9:9-13 Roles of basophils in allergy 1) In sensitized animals, specific IgE are produced and captured by circulating basophils through FcεrI 2) When the same antigens enter skin, IgE-bearing basophils are recruited to lesion, possibly by chemokines released by phagocytic cells that have captured antigen, and are activated when Ag binds to IgE–FcεrI complex 3) Activated basophils secrete cytokines and other factors that in turn act on tissue-resident cells, such as fibroblasts, 4) Induce them to produce more chemokines 5) Inflammatory cells, such as eosinophils and neutrophils, are then recruited to skin lesion in response to chemokines that are released by tissue-resident cells , resulting in chronic allergic inflammation
  44. 44. Role of basophils in allergic diseases Important in many if not all allergic diseases: • Anaphylaxis • Allergic rhinitis • Asthma • Urticaria • Food allergies Cromheecke JL. et. al. Curr Allergy Asthma Rep 2014;14:408
  45. 45. Role of basophils in other clinical conditions • Infections • Autoimmunity • Malignancy Cromheecke JL. et. al. Curr Allergy Asthma Rep 2014;14:408
  46. 46. http://www.dailymail.co.uk/sciencetech/article-2957265/When-white-blood-cells-ATTACK-Amazing-video-captures-moment-immune-takes-parasitic-worm.html Immune system takes down a worm Access from http://i.dailymail.co.uk, November 2015 Caenorhabditis elegans
  47. 47. Voehringer D. Trends Parasitol 2009;25:551-6 Schroeder JT. Middleton’s Allergy Principle and Practice. 8th edition, 2014 Long-held belief that basophils (and eosinophils) are involved in natural immunity to parasitic infections IL-4–secreting basophils are critical for expulsion of these worms
  48. 48. Role of basophils in other clinical conditions • Infections • Autoimmunity • Malignancy Cromheecke JL. et. al. Curr Allergy Asthma Rep 2014;14:408
  49. 49. Charles N and Rivera J. Curr Allergy Asthma Rep 2011;11:378–87 Cromheecke JL. et. al. Curr Allergy Asthma Rep 2014;14:408 Correlations between elevated serum IgE autoantibodies, and activated basophils with severity of lupus nephritis IgE anti-dsDNA/dsDNA immune complexes bind to basophils FcεRI, causing basophil activation with homing to lymphoid organs Activated basophils produce IL-4 and promote Th2 adaptive immune response that enhances autoantibody production
  50. 50. Schuerwegh JM, et al. PNAS. 2010;107:2586–91 Cromheecke JL. et. al. Curr Allergy Asthma Rep 2014;14:408 Rheumatoid arthritis Citrullinated proteins can activate basophils due to IgE anti-citrullinated protein Basophil activation may contribute to pathogenesis of autoimmune diseases as diverse as: • Antiglomerular basement membrane disease • Membranous nephropathy • ANCA associated vasculitis
  51. 51. Cromheecke JL. et. al. Curr Allergy Asthma Rep 2014;14:408 Stone KD., et. al. J Allergy Clin Immunol 2010;125:S73-80 Kawakami T. and Galli SJ. Nature Reviews Immunology 2002;2:773-86 Indirect therapeutic modulation of basophil activation, such as omalizumab, will be extended to direct therapeutic targeting of basophils to inhibit activation and promotion of a pathogenic Th2 microenvironment
  52. 52. Role of basophils in other clinical conditions • Infections • Autoimmunity • Malignancy Cromheecke JL. et. al. Curr Allergy Asthma Rep 2014;14:408
  53. 53. Wimazal F. et. al. Cancer 2010;116:2372-81 Cromheecke JL. et. al. Curr Allergy Asthma Rep 2014;14:408 Retrospective study of prognostic significance of eosinophils and basophils in 1008 patients with de novo MDS in Austria & German Increased no. of basophils are common features of AML and accelerated phase of CML Basophils, greater than 250/ul, was associated with reduced survival
  54. 54. Nievergall E. et. al. Blood 2014;123:1218-28
  55. 55. Hoffmann HJ. et. al. Allergy 2015;70:1393-405 Karasuyama H. et. al. Nature Reviews Immunology 2009;9:9-13 measures basophil response to allergen cross-linking IgE Basophil activation test (BAT) Compared with determination of sIgE in serum, BAT reflects a functional response as basophil activation can be induced by cross-linking of FceRI, which requires more than binding of sIgE to allergen
  56. 56. Diagnostic evaluation Determine clinically relevant allergen in addition to clinical history, skin prick test, and specific IgE • Food • Insect venom • Drug allergy • Chronic urticaria: Alternative for autologous serum skin test (ASST) Basophils from healthy donors are challenged with patients’ serum Hoffmann HJ. et. al. Allergy 2015;70:1393-405
  57. 57. Hoffmann HJ. et. al. Allergy 2015;70:1393-405
  58. 58. Sensitivity & specificity • Drug allergy: Beta-lactams, Neuromuscular blocking agent (NMBA), quinolones , radio contrast media, and pyrazolones sensitivity 50%, specificity up to 93% • Food allergy: sensitivity 77-98%, specificity 75 – 100 % • Hymenoptera venom allergy: sensitivity 85-100%, specificity 83 – 100 % Hoffmann HJ. et. al. Allergy 2015;70:1393-405
  59. 59. Monitor patients • Allergen immunotherapy • Anti-IgE treatment • Natural resolution of allergy Hoffmann HJ. et. al. Allergy 2015;70:1393-405
  60. 60. Hoffmann HJ. et. al. Allergy 2015;70:1393-405 Basophil reactivity is the dose (range) at which maximal response occurs Basophil sensitivity is the dose at which half of the maximal response occurs Concentration at which 50% of basophils respond = EC50 ‘CD-sens’ = 1/EC50 x 100
  61. 61. Hoffmann HJ. et. al. Allergy 2015;70:1393-405 Basophil reactivity reflected severity Basophil sensitivity reflected threshold of response to allergen
  62. 62. Hoffmann HJ. et. al. Allergy 2015;70:1393-405
  63. 63. Advantages • Fewer resources • More reproducible than challenge test • Less stressful for the patient • Avoids severe allergic reactions Hoffmann HJ. et. al. Allergy 2015;70:1393-405
  64. 64. Nonresponders • 6–17% of population • Nonresponders can experience allergic symptoms and have positive SPT with relevant allergens • Remain unresponsive to stimulation through FceRI under standard BAT conditions Hoffmann HJ. et. al. Allergy 2015;70:1393-405
  65. 65. Kepley CL, et. al. J Allergy Clin Immunol 1999;104:279-84 Differences in intracellular signaling pathway
  66. 66. Considerations when taking a blood sample for BAT (1) • Remember to… Check absolute basophil counts of above 50 cells/µl within 24 hours prior to performing BAT Personal communication, Jettanong Klaewsongklam, M.D., 2015
  67. 67. Considerations when taking a blood sample for BAT (2) • Antihistamines do not influence BAT but systemic steroids and cyclosporin A should be avoided • Blood samples should preferentially be taken within 1 yr of the most recent exposure to allergen • It is possible to use blood samples within 24 h to document sensitization, but may lose reactivity Hoffmann HJ. et. al. Allergy 2015;70:1393-405
  68. 68. Considerations when taking a blood sample for BAT (3) • Basophil function is mostly assessed in heparin-stabilized blood Hoffmann HJ. et. al. Allergy 2015;70:1393-405
  69. 69. Hoffmann HJ. et. al. Allergy 2015;70:1393-405
  70. 70. Allergen concentration range Benzylpenicillin 2 &0.4 mg/ml Amoxicillin 1.25 & 0.25 mg/ml PPL 0.25 & 0.05 mg/ml MDM 0.25 & 0.05 mg/ml Cephalosporins 1.25 & 0.25 mg/ml ASA 1 & 0.2 mg/ml Diclofenac 0.3 & 0.06 mg/ml Naproxen 1 & 0.2 mg/ml Paracetamol 1 & 0.2 mg/ml Metamizol 2.5 & 0.25 mg/ml Atracurium 0.5 &0.05 mg/ml Vecuronium 2-0.5 mg/ml Hoffmann HJ. et. al. Allergy 2015;70:1393-405 Negative test with a parent drug does thus not rule out that reacts to a metabolite of drug
  71. 71. Summary (1) • Basophils have long been seen as a surrogate with which to study the more elusive mast cell. This view, however, is no longer valid, because substantial developmental and physiologic evidence now shows that these two cell types have more differences than similarities Schroeder JT. Middleton’s Allergy Principle and Practice. 8th edition, 2014
  72. 72. Summary (2) • Once thought to do little other than to secrete histamine and LTC4, basophils are now well recognized to be the predominant cellular source of IL-4 and IL-13—perhaps the two most important cytokines with a role in the pathogenesis of allergic disease Schroeder JT. Middleton’s Allergy Principle and Practice. 8th edition, 2014
  73. 73. Summary (3) • This information, along with evidence that these cells infiltrate allergic lesions and are capable of responding to a wide variety of stimuli, has sparked a renewed interest in basophils and in their role in allergic inflammation and disease. Schroeder JT. Middleton’s Allergy Principle and Practice. 8th edition, 2014
  74. 74. Thank you for your attention

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