Effect of prednisone on nasal symptoms and peripheral blood T-cell function in chronic rhinosinusitis

Abstract

Background: Systemic corticosteroids are the most effective anti-inflammatory drugs used for controlling chronic rhinosinusitis (CRS) symptoms. The potential mechanisms for their beneficial effects include increasing the number and function of T regulatory cells (Tregs), as reported in the local tissue post-intranasal steroid treatment. We investigated the effect of systemic corticosteroids on peripheral blood (PB) Tregs in subjects with CRS.

Methods: Twenty CRS subjects and 19 controls were recruited. PB mononuclear cells (PBMCs) were isolated from CRS subjects before and after systemic corticosteroid administration in the course of clinical treatment. Control subjects received no treatment and were studied at one visit. Nasal symptoms were recorded. CD4(+) CD25(+) Foxp3(+) cells (Tregs) were analyzed by flow cytometry. Messenger RNA (mRNA) levels for interferon γ (IFN-γ), interleukin 4 (IL-4), IL-10, IL-13, IL-17A, transforming growth factor β1 (TGF-β1), forkhead box P3 (FoxP3), and GATA-binding factor 3 (GATA-3) were measured in PBMCs using real-time polymerase chain reaction (PCR).

Results: CRS subjects reported improved nasal symptoms (p = 0.005) and significantly reduced PB Tregs after treatment with corticosteroids (p = 0.042). The transcript levels of IL-4 and GATA-3 were significantly higher in the CRS subjects at their first visit when compared to controls (p = 0.019 and p = 0.05, respectively). Corticosteroid treatment lowered the transcript levels of immunoregulatory transcription factors [FoxP3 (p = 0.048) and GATA-3 (p = 0.012)] and IFN-γ (p = 0.036) in PB.

Conclusion: In contrast to prior work in local nasal tissue, our study reports reduced PB Tregs and decreased T helper 1 (T(H)1) and T(H)2 function after treatment with systemic corticosteroids. These data indicate that corticosteroid effects on Tregs in CRS are complex involving local signals in the tissue that are distinct from those in circulating cells.

Trial registration: ClinicalTrials.gov NCT01002313.

Keywords: FoxP3; GATA-3; IFN-γ; IL-4; T regulatory cell; chronic rhinosinusitis; nasal polyps; peripheral blood mononuclear cells; prednisone; systemic steroids.

Conflict of interest statement

Potential conflict of interest: None.

© 2014 ARS-AAOA, LLC.

Figures

FIGURE 1

Representative 2-dimensional scatter diagram of (A) CD4+ (FITC) CD25+ (APC) cells from the lymphocyte population of PBMCs analyzed in (B, C); (B) CD4+CD25+ cells stained with anti-human FoxP3 (PE) antibody (CD4+CD25+FoxP3+ Tregs); and (C) CD4+CD25+ cells stained with the isotype control antibody (rat IgG2a-PE); (D) percentage of CD4+CD25+FoxP3+ Tregs in PBMCs of healthy controls (circles) and CRS subjects (visit 1: open squares, CRSsNP subjects; filled squares, CRSwNP subjects); and (E) in PBMCs of CRS subjects (open circles: CRSsNP subjects; closed circles: CRSwNP subjects) before (visit 1) and after (visit 2) administration of prednisone. The dark bars represent the medians. APC = allophycocyanin; CRSsNP = chronic rhinosinusitis without nasal polyps; CRSwNP = chronic rhinosinusitis with nasal polyps; FITC = fluorescein isothiocyanate; FoxP3 = forkhead box P3; IgG2a = immunoglobulin G2a; PBMC = peripheral blood mononuclear cell; PE = phycoerythrin; Treg = T regulatory cell.

FIGURE 2

Transcript levels (normalized to the levels of β-actin) of (A) FoxP3, (B) IL-10, (C) TGF-β1, (D) GATA-3, (E) IL-4, (F) IL-13, (G) IFN-γ, and (H) IL-17A from PBMCs of CRS subjects before and after administration of prednisone. CRS = chronic rhinosinusitis; FoxP3 = forkhead box P3; GATA-3 = GATA-binding factor 3; IFN-γ = interferon γ ; IL = interleukin; mRNA = messenger RNA; TGF-β1 = transforming growth factor β1; PBMC = peripheral blood mononuclear cell.