DISCUSSION
Most of pathophysiology of CSU can be understood from histopathological
studies of urticarial lesions.3 Barsilay et
al.14 described histopathological changes in urticaria
biopsies by demonstrating the presence of numerous cells apart from mast
cells, such as eosinophils, lymphocytes, and neutrophils, in the
skin.14 In a study conducted by our group in 2016, we
demonstrated that urticaria with predominance of eosinophils was related
to greater clinical activity of the disease.15 Other
authors have described the presence of CD4+ T
lymphocytes, variable number of monocytes, basophils, and
lymphocytes.2,16 The cytokines involved in the
inflammatory skin process in urticaria reveal a mixed cytokine pattern
with an increase in IL-4, IL-5, and IFN gamma.16 In
1990, Czarnetzki et al.17 described the presence of
macrophages in acute, chronic, and Delayed Pressure Urticaria; and, with
the scarce resources available at the time for immunohistochemistry,
they observed macrophage cell activation in the lesioned
skin.17 Neverthless any previous study has
demonstrated the role of macrophage subpopulations (M1/M2 phenotype) in
CSU.
In a previous study, we observed a cellular interaction between
dendrocytes and mast cells in the microvascular unit of the dermis,
using immunoelectronic microscopy.4 The observation
allowed us to assume that the macrophage could participate as adjuvant
of the immunological response in urticaria; however, their role was not
completely established at the time.4 An interaction
with macrophages can occur via release of histamine and cytokines such
as IL-1 beta, IL-6, and IL-13 in addition to prostaglandin D2 (PGD2) and
platelet activating factor (PAF).2 PGD2, PGE2, IL-1
beta, IL-9, and histamine also influence the dendritic
cells.18 The activation of macrophages and dendritic
cells has been postulated to be involved in the pathophysiology of
urticaria.2,18
Macrophages basically perform two functions: (i) killer function, when
their function is to eliminate a pathogen or defective cell, which
basically depends on M1 populations or (ii) repair, when their functions
involve regulation of immune response, angiogenesis, and healing, which
depends on M2 macrophages, also termed as “alternatively activated
macrophages.6,18,19 In addition to the normal repair
function, the M2 macrophage is related to the chronicity of diseases and
worse immune responses in the in vitro studies in sepsis,
infectious diseases, autoimmune diseases, and vascular
diseases.7,9-13,19
The presence of M2 macrophages in tumors is related to a worse prognosis
and formation of metastases.19
Few studies have linked the presence of M1 and M2 macrophages in
allergic diseases or in diseases in which the participation of mast
cells is important, such as urticaria.9,10 In these
diseases, M2 macrophages are related to chronicity, worse immune
response or worse prognosis.9,10,19,20
The imbalance between TH1/TH2 cytokines has long been considered as a
possible mechanism for urticaria. Chen et al.21observed a mixture of TH1/TH2 cytokines in urticaria, in addition to
TH17 cytokines.21 In patients with chronic urticaria,
there was a predominance of the TH2 pathway, in addition to an increase
in GM-CSF.21 The change to M2 macrophages is activated
by the presence of IL-10, IL-4, IL-13, GM-CSF, IL-6, corticosteroids,
apoptotic debris, and hypoxia, that is, the change is induced by local
inflammatory milieu, in order to antagonize and resolve an inflammatory
process.5-13,19,22
In the present study, we observed a predominance of the CD163, CD206,
and CMAF receptors, compared to pSTAT-1 (M1 macrophage marker),
regardless of age, sex, and laboratory tests evaluated, demonstrating
that in uncontrolled CSU with maximum doses of second generation
anti-H1, in general, the macrophage subtype found is an alternatively
activated phenotype (M2).7,8,11,19,21
While studying the immunohistochemical markers in the skin of control
individuals, a statistically significant relationship was found with the
CMAF marker, which is related to the transcription of cytokines
responsible for macrophage and lymphocytic
activation.12,22 In studies conducted in mice, CMAF
deficiency is directly related to the loss of expression of the F4/80
factor, which regulates the migration of macrophages to peripheral
tissues and directly influences IL-4 production.23,24This observation is important, since the expression of CMAF was
statistically significant compared to the control individuals, due to
the fact that this nuclear transcription factor is constitutionally
expressed in a small amount in resident macrophages; however, IL-4 can
positively or negatively regulate its production.23
Gabryšová et al.26 demonstrated that CMAF in
lymphocytes may be implicated in several normal biological processes and
in allergic and autoimmune diseases, because it suppresses the synthesis
of IL-2 in CD4+ lymphocytes, activates T helper2 (TH2) cells in allergy,
and further activates TH17 lymphocytes, leading to the onset of
autoimmune diseases.26 Since our patients had
urticaria refractory to antihistamines and high clinical activity of
urticaria, a hypothesis could be that a higher expression of CMAF is the
result of an exaggerated stimulation mediated by IL-4 and IL-13
cytokines.19,23
CMAF leads to the production of IL-10 and activation of the TH17
pathway, in addition to the perpetuation of TH2-mediated inflammation,
which could prolong the inflammatory process and contribute to the
maintenance and chronicity of urticaria.20,21,23Another possible explanation would be the continued or intermittent use
of systemic corticosteroids by patients with urticaria refractory to
antihistamine drugs, which also induces the formation of M2 macrophages
with activation of CMAF.1,19,22
The immunohistochemical marker CD206 was negatively associated with the
evolution of CSU in our patients. The macrophage mannose receptor (MMR
or CD206) is highly expressed in M2 macrophages, strongly induced by
IL-4 and IL-13, but not in M1 macrophages.7,19Simultaneously, it is the first receptor to be activated in case of
trauma or tissue injury, which leads to the activation of STAT-6, while
stimulating the synthesis of TH2 cytokines (IL-4 and IL-13) e
IL24.19,20,27 Scmettzer et al28showed that in CSU patients had IgE autoantibodies against IL24 linked
with the disease activity. We can infer that in anti-histamines
resistant patients we could have a continuous production of IL24 by the
M2 macrophage that estimulate the mast cell through IgE anti IL2427,28
We showed a decrease in the concentration of the CD206 in relationship
with the course of the disease. One possible explanation could be the
fact that more recent studies demonstrate the existence of four subtypes
of M2 macrophages.19 We presently know that M2
macrophages can be subdivided into four subpopulations, depending on the
stimulus received: (i) M2a, stimulated predominantly by cytokines IL-4
and IL-13 and JAK-1 and JAK-3 receptors, is a high affinity receptor for
IgE and increases the concentrations of CD206; (ii) M2b, stimulated by
immunocomplexes, increases the secretion of proinflammatory cytokines;
(iii) M2c, stimulated by corticosteroid binding to its receptors IL10
and TGF beta; and (iv) M2d, stimulated by high concentrations of IL-10
and tumor factors.9,19,20 CD206 is highly expressed by
M2a macrophages but is diminished in the other subtypes and its
expression changes according to the influence of the inflammatory
milieu; thus, we can assume that an attempt to resolve the inflammatory
process is observed in chronic urticaria.
One explanation for M2 macrophages being activated in CSU would be the
possibility of elevating IL-25, an IL-17 family cytokine, produced by
several cells activated in urticaria, including mast cells, dendrocytes,
and eosinophils.29 This could contribute to the
presence of activated M2 macrophages in urticaria, indirectly revealed
in our study, as it is associated with the increase in
CMAF.26,29.
In an immunohistochemical study of eight skin biopsies of urticaria
cases, Kay et al.29 observed an increase in the IL-25
expression in mast cells and eosinophils of patients with urticaria.
IL-25 belongs to the IL-17 cytokine family and is a potent promoter of
TH2 response, and increased expression can be observed in epithelial
cells, mast cells, and eosinophils in urticaria
lesions.2,29 The observation that mast cells can
produce IL-25, followed by an IgE-dependent activation suggests a
possible innate immunity pathway that can trigger or amplify TH2
responses.2,29 A second member of the IL-17 family,
thymic stromal lymphopoietin (TSLP), is also elevated in mast cells in
asthma and mast cell cultures.2 TSLP does not induce
mastocytic degranulation; however, it increases the recruitment of mast
cells and dendrocytes in the skin.30
Mast cells are negatively regulated via activation of phosphoinositide
lipid phosphatases (in general, SHIP 1 and 2) and their deregulation and
decreased activity are associated with CSU. The increased activity of
SHIP 1 and 2 is related to a deviation in the M1 phenotype of
macrophages. Therefore, the deregulation of SHIP could also explain the
increase in M2 macrophages.30,31
Recently, the presence of new vessels (neoangiogenesis) has been
described in patients with CSU. Kay et al.32 reported
that the injured skin of patients with urticaria displays increased
dermal vascularization.32 VEGF is a regulatory factor
of angiogenesis, inducing endothelial cell proliferation, migration, and
secretion of metalloproteinase 1 (MMP1).3,30 Moreover,
VEGF promotes the expression of von Willebrand factor, in addition to
adhesion molecules such as ICAM-1, VCAM-1, and
E-selectin.33 VGEF has been implicated as an induction
factor of M2 macrophage polarization.32,33 Macrophage
M2 in turn can promote angiogenesis by releasing IL10, TGF-beta, and
other cytokines, which results in greater vascularity found in the skin
of patients with chronic urticaria.7,33
The present study had limitations, as we were not able to subclassify
the type of M2 macrophages, as already done in patients with asthma and
contact dermatitis.8,19,20 This subcategory would
allow us to observe subtypes of M2 macrophages, which could lead to
specific treatments for these patients.
In conclusion, in the CSU patients studied, a predominance of M2
macrophages was observed, with significantly higher CMAF expression,
which indicates macrophage activation in patients with CSU. Moreover, we
observed a negative correlation between the presence of the CD206 marker
and the duration of CSU. Further studies are warranted to focus on
therapies targeting M2 macrophage subtypes in patients with urticaria
refractory to antihistamines in order to assess their contribution in
deciding the best treatment for this disease.
- Zuberbier T, Aberer W, Asero R, et al. The EAACI/GA²LEN/EDF/WAO
guideline for the definition, classification, diagnosis and management
of urticaria.Allergy . 2018;73(7):1393–1414.
- Church MK, Kolkhir P, Metz M, Maurer M. The role and relevance of mast
cells in urticaria.Immunol Rev . 2018;282(1):232–247.
doi:10.1111/imr.12632
- Puxeddu I, Pratesi F, Ribatti D, Migliorini P. Mediators of
Inflammation and Angiogenesis in Chronic Spontaneous Urticaria: Are
They Potential Biomarkers of the Disease?.Mediators Inflamm .
2017;2017:4123694. doi:10.1155/2017/4123694
- Criado PR, Jardim Criado RF, Sotto MN, Pagliari C, Takakura CH,
Vasconcellos C. Dermal dendrocytes FXIIIA+ phagocytizing extruded mast
cell granules in drug-induced acute urticaria.J Eur Acad
Dermatol Venereol . 2013;27(1):e105–e112.
doi:10.1111/j.1468-3083.2012.04556.x
- Yang Z, Grinchuk V, Urban JF Jr, et al. Macrophages as
IL-25/IL-33-responsive cells play an important role in the induction
of type 2 immunity. PLoS One . 2013;8(3):e59441.
doi:10.1371/journal.pone.00594
- Wang N, Liang H, Zen K. Molecular mechanisms that influence the
macrophage m1-m2 polarization balance. Front Immunol .
2014;5:614. doi:10.3389/fimmu.2014.00614.
- Shapouri-Moghaddam A, Mohammadian S, Vazini H, et al. Macrophage
plasticity, polarization, and function in health and disease. J
Cell Physiol . 2018;233(9):6425-6440. doi:10.1002/jcp.26429
- Barros
MH1,
Hauck
F,
Dreyer
JH,
Kempkes
B,
Niedobitek
G. Macrophage polarisation: an immunohistochemical approach for
identifying M1 and M2 macrophages. PLoS One. 2013 doi: 10.1371
- Saradna A, Do DC, Kumar S, Fu QL, Gao P. Macrophage polarization and
allergic asthma. Transl Res . 2018;191:1–14.
doi:10.1016/j.trsl.2017.09.002
- Takabayashi T, Kato A, Peters AT, Hulse KE, Suh LA, Carter R, Norton
J, Grammer LC, Tan BK, Chandra RK, Conley DB, Kern RC, Fujieda S,
Schleimer RP.
Increased
expression of factor XIII-A in patients with chronic rhinosinusitis
with nasal polyps.. J Allergy Clin Immunol. 2013;132(3):584-592.e4.
doi: 10.1016/j.jaci.2013.02.003.
- Palmer
MB1,
Vichot
AA2,
Cantley
LG2,
Moeckel
GW1. Quantification and localization of M2 macrophages in human
kidneys with acute tubular injury . Int J Nephrol Renovasc Dis. 2014
Nov 7;7:415-9
- de Carli ML, Miyazawa M, Nonogaki S, et al. M2 macrophages and
inflammatory cells in oral lesions of chronic
paracoccidioidomycosis. J Oral Pathol Med . 2016;45(2):141–147.
doi:10.1111/jop.12333
- Chávez-Galán Leslie, Olleros Maria L., Vesin Dominique, Garcia I. Much
More than M1 and M2 Macrophages, There are also CD169+ and TCR+
MacrophagesFront. Immunol., 26 May 2015
| https://doi.org/10.3389/fimmu.2015.00263
- Barzilai A, Sagi L, Baum S, et al. The Histopathology of Urticaria
Revisited-Clinical Pathological Study. Am J Dermatopathol .
2017;39(10):753-759. doi:10.1097/DAD.0000000000000786
- Marques RZ, Criado RF, Machado CD Filho, Tamanini JM, Mello CV, Speyer
C. Correlation between the histopathology of chronic urticaria and its
clinical picture. An Bras Dermatol . 2016;91(6):760-763.
doi:10.1590/abd1806-4841.20165066
- M. Caproni, B. Giomi, W. Volpi et al., “Chronic idiopathic urticaria:
infiltrating cells and related cytokines in autologous serum-induced
wheals,” Clinical Immunology, vol. 114, no. 5 pp. 284–292, 2005
- Czarnetzki BM, Zwadlo-Klarwasser GZ, Bröcker EB, Sorg C. Macrophage
subsets in different types of urticaria. Arch Dermatol Res .
1990;282(2):93-97. doi:10.1007/BF00493465
- Varricchi G, Rossi FW, Galdiero MR, et al. Physiological Roles of Mast
Cells: Collegium Internationale Allergologicum Update 2019. Int
Arch Allergy Immunol . 2019;179(4):247-261. doi:10.1159/000500088
- Shrivastava R, Shukla N. Attributes of alternatively activated (M2)
macrophages. Life Sci . 2019;224:222–231.
doi:10.1016/j.lfs.2019.03.062.
- Suzuki K, Meguro K, Nakagomi D, Nakajima H. Roles of alternatively
activated M2 macrophages in allergic contact
dermatitis. Allergol Int . 2017;66(3):392–397.
doi:10.1016/j.alit.2017.02.015
- Chen Q, Zhong H, Chen WC, et al. Different expression patterns of
plasma Th1-, Th2-, Th17- and Th22-related cytokines correlate with
serum autoreactivity and allergen sensitivity in chronic spontaneous
urticaria. J Eur Acad Dermatol Venereol . 2018;32(3):441-448.
doi:10.1111/jdv.14541
- Tu GW, Shi Y, Zheng YJ, et al. Glucocorticoid attenuates acute lung
injury through induction of type 2 macrophage. J Transl Med .
2017;15(1):181. Published 2017 Aug 29. doi:10.1186/s12967-017-1284-7
- Cao S, Liu J, Song L, Ma X. The protooncogene c-Maf is an essential
transcription factor for IL-10 gene expression in macrophages. J
Immunol . 2005;174(6):3484–3492. doi:10.4049/jimmunol.174.6.3484
- Bauquet, A.T., et al., 2009. The costimulatory molecule ICOS regulates
the expression of c-Maf and IL-21 in the development of follicular T
helper cells and TH-17 cells.Nat. Immunol. 10, 167–175
- Nakamura M, Hamada M, Hasegawa K, et al. c-Maf is essential for the
F4/80 expression in macrophages in vivo. Gene .
2009;445(1-2):66-72. doi:10.1016/j.gene.2009.06.003
- Gabryšová L, Alvarez-Martinez M, Luisier R, et al. c-Maf controls
immune responses by regulating disease-specific gene networks and
repressing IL-2 in CD4+ T cells [published
correction appears in Nat Immunol. 2019 Mar;20(3):374]. Nat
Immunol . 2018;19(5):497–507. doi:10.1038/s41590-018-0083-5
- Dabitao D, Hedrich CM, Wang F, Vacharathit V, Bream JH. Cell-Specific
Requirements for STAT Proteins and Type I IFN Receptor Signaling
Discretely Regulate IL-24 and IL-10 Expression in NK Cells and
Macrophages. J Immunol . 2018;200(6):2154-2164.
doi:10.4049/jimmunol.1701340
- Schmetzer O, Lakin E, Topal FA, et al. IL-24 is a common and specific
autoantigen of IgE in patients with chronic spontaneous
urticaria. J Allergy Clin Immunol . 2018;142(3):876-882
- Kay AB, Clark P, Maurer M, Ying S. Elevations in T-helper-2-initiating
cytokines (interleukin-33, interleukin-25 and thymic stromal
lymphopoietin) in lesional skin from chronic spontaneous
(’idiopathic’) urticaria. Br J Dermatol .
2015;172(5):1294–1302. doi:10.1111/bjd.13621
- Dobranowski P, Sly LM. SHIP negatively regulates type II immune
responses in mast cells and macrophages [published online ahead of
print, 2018 Jan 17]. J Leukoc Biol .
2018;10.1002/JLB.3MIR0817-340R. doi:10.1002/JLB.3MIR0817-340R
- Bracken SJ, Abraham S and MacLeod AS (2019) Autoimmune Theories of
Chronic Spontaneous Urticaria. Front. Immunol. 10:627. doi:
10.3389/fimmu.2019.00627
- Kay AB, Ying S, Ardelean E, et al. Elevations in vascular markers and
eosinophils in chronic spontaneous urticarial weals with low-level
persistence in uninvolved skin. Br J Dermatol .
2014;171(3):505-511. doi:10.1111/bjd.12991
- Wheeler KC, Jena MK, Pradhan BS, et al. VEGF may contribute to
macrophage recruitment and M2 polarization in the decidua. PLoS
One . 2018;13(1):e0191040. Published 2018 Jan 11.
doi:10.1371/journal.pone.0191040