Clinical examinations and immunohistochemical markers
Of the 28 patients, five did not
undergo ASST due to the impossibility of removing antihistamines;
therefore, the analysis was performed separately. Regarding the ASST
results, the comparison did not indicate significant differences between
negative versus positive results, for any of the immunohistochemistry
markers (for M1 or M2 phenotypes) evaluated (p >
0.05). The correlations between the immunohistochemical markers and PCR,
D DIMMER, were all nonsignificant (p > 0.05) and did
not reveal a direct relationship between the complementary tests and
macrophage phenotypes.
The cutaneous expression of the two populations of macrophages, M1
represented by STAT1 and M2 represented by CD163, CMAF, and CD206, was
compared. The descriptive results of these markers are illustrated in
Figures 1 and 2 and Table 3.
No significant differences were found between the skin samples of
patients with CSU and of the control population for the
immunohistochemical markers CD163, CD206, and pSTAT-1 (Table 3 and
Figure 1).
The expression of the immunohistochemical marker CMAF was significantly
higher in the CSU patients compared to the controls of apparently normal
skin (p < 0.001; Table 3 and Figure 1).
The skin expression of pSTAT-1 was significantly lower than CD163
(p < 0.001), CMAF (p < 0.001), and
CD206 (p < 0.001) in patients with CSU, demonstrating a
clearly M2 phenotypic pattern of macrophage response (Figure 2).
No significant difference was found between pSTAT-1 and CMAF in the skin
of control individuals (p = 0.181). Images obtained from slides
with immunohistochemical staining are depicted in Figure 3.
Table 3. Descriptive statistics by immunohistochemical markers
and subpopulation of macrophages in patients with spontaneous chronic
urticaria and control subjects.