Photomicrographs showing the parietal pleura (A, B) and positive control tonsil (C) immunostained for identification of FOXP3+ cells (A–C).

<p>FOXP3 positive cells are stained brown. Photomicrograph D shows the negative control slide of tonsil immunostained using normal nonspecific immunoglobulins. Results are representative of those from 14 patients with PLTB (A) and 12 patients with NSP (B). Original magnification: 400×. The scale bar represents 50 µm.</p

Photomicrographs showing the parietal pleura (A, B) and positive control nasal polyp (C) immunostained for CRTH2 (A–C).

<p>CRTH2+ cells are stained in red. Photomicrograph D shows negative control slide of nasal polyp immunostained using normal nonspecific immunoglobulins. Results are representative of those from 14 patients with PLTB (A) and 12 patients with NSP (B). Original magnification: 400×. The scale bar represents 50 µm.</p

Summary of the double staining immunohistochemical procedures.

<p>DAB: 3,3′-diaminobenzidine tetrahydrochloride.</p

Photomicrographs showing the parietal pleura (A and B) and control tonsil (C and D) immunostained for identification of CD4+ cells (A–C).

<p>Photomicrographs D shows negative control slide of tonsils stained with normal nonspecific immunoglobulins of the same animal species of the primary antibody used at the same protein concentration as the primary antibody. CD4+ cells are stained in brown. Results are representative of those from 14 patients with PLTB (A) and 12 patients with NSP (B). Original magnification: 400×. The scale bar represents 50 µm.</p

Summary of the immunohistochemical procedures used to detect the Th1, Th2 and Tregs cells.

<p>Th1: T-helper type 1; Th2: T-helper type 2; Tregs: regulatory T cells; CCR: chemokine CC motif, receptor; CXC: chemokine CXC motif, receptor; T-bet: T box expressed in T cells; CRTH2: chemoattractant receptor-homologous molecule expressed on Th2; STAT: signal transducer and activator of transcription; GATA3: GATA motif binding protein 3; FOXP3: Forkhead box protein 3. AEC: 3-amino-9-ethylcarbazole; DAB: 3,3′-diaminobenzidine tetrahydrochloride.</p

Photomicrographs showing the parietal pleura (A, B) and control tonsil (C and D) immunostained for identification of CD68+ cells (A–C).

<p>Photomicrograph D shows negative control slide of tonsils stained with normal nonspecific immunoglobulins of the same animal species of the primary antibody used at the same protein concentration as the primary antibody. CD68+ cells are stained in brown. Results are representative of those from 14 patients with PLTB (A) and 12 patients with NSP (B). Original magnification: 400×. The scale bar represents 50 µm.</p

Photomicrographs showing the parietal pleura (A and B) immunostained for GATA-3+ cells or the parietal pleural (C and D) double immunostained for GATA-3+ cells and tryptase+ cells.

<p>GATA-3 is stained in red in A and B and brown in C and D. Tryptase is stained in red. Results are representative of those from 14 patients with PLTB (A and C) and 12 patients with NSP and (B and D). Original magnification: 400×. The scale bar represents 50 µm.</p

Photomicrographs showing the parietal pleura (A, B) and positive control tonsil (C) immunostained for identification of STAT4+ cells (A–C).

<p>STAT4, positive cells are stained brown. Photomicrograph D shows the negative control slide of tonsil immunostained using normal nonspecific immunoglobulins. Results are representative of those from 14 patients with PLTB (A) and 12 patients with NSP (B). Original magnification: 400×. The scale bar represents 50 µm.</p

Photomicrographs showing the parietal pleura (A, B) and positive control tonsil (C and D) immunostained for identification of STAT6+ cells (A–C).

<p>STAT6+ cells are stained brown. Photomicrograph D shows negative control slide of tonsil immunostained using normal nonspecific immunoglobulins. Results are representative of those from 14 patients with PLTB (A) and 12 patients with NSP (B). Original magnification: 400×. The scale bar represents 50 µm.</p

Photomicrographs showing the parietal pleura stained for eosinophils using hematoxylin and eosin (H/E) histochemical staining (A and B).

<p>Eosinophil granulocytes+ cells are stained in pink. Results are representative of those from 14 patients with PLTB (A) and 12 patients with NSP (B). Original magnification: 400×. The scale bar represents 50 µm.</p