Vitamin D supplementation decreases Aspergillus fumigatus specific Th2 responses in CF patients with aspergillus sensitization: a phase one open-label study

Abstract

Background: Patients with cystic fibrosis (CF) complicated by allergic bronchopulmonary aspergillosis (ABPA) are vitamin D deficient and in vitro treatment with 1,25 (OH)2 vitamin D3 of CD4+ cells from CF patients with ABPA decreases Aspergillus fumigatus(Af)-induced Th2 responses. This Phase I clinical trial investigated the safety and effectiveness of daily vitamin D3 supplementation in CF patients with ABPA to reduce allergic responses and ABPA symptoms, and increase serum vitamin D levels.

Methods: Seven patients ages 12 years and older with a clinical diagnosis of CF and ABPA with current evidence of Af sensitization received 4000 IU vitamin D3 (cholecalciferol) daily for 24 weeks. The primary outcome of the study was safety followed by the Aspergillus induced IL-13 response in CD4+ T cells to test the hypothesis that vitamin D supplementation is safe and reduces Aspergillus induced IL-13 responses in CD4+ T cells. Secondary outcomes included total IgE, Aspergillus-specific IgE, vitamin D levels, FEV1, urinary calcium/creatinine ratio, and cytokine production by Aspergillus-stimulated peripheral blood T cells.

Results: Six months of vitamin D3 supplementation resulted in significant increases in serum 25-(OH) vitamin D level, and the treatment was well tolerated without evidence of vitamin D toxicity or hypercalcemia. There were no serious adverse events. Daily vitamin D supplementation led to significantly decreased Aspergillus induced IL-13 responses between the baseline visit and that at 24 weeks (p = 0.04). Aspergillus-specific IgE level was also significantly decreased after 8 (p = 0.035) and 24 weeks of daily vitamin D supplementation (p = 0.04).

Conclusions: 4000 IU vitamin D3 daily over a 24-week period is well tolerated in CF patients with a history ABPA and current evidence of Th2 immunity to Af. . Daily vitamin D supplementation was associated with reduced Aspergillus induced IL-13 responses from peripheral. . CD4+ T cells and Aspergillus-specific IgE levels, as well as increased serum vitamin D levels. This treatment was well tolerated and the study supports further investigation of the use of vitamin D supplementation in Th2 mediated diseases.

Trial registration: This trial was registered at www.clinicaltrials.gov as NCT01222273.

Keywords: Allergic bronchopulmonary aspergillosis; Cystic fibrosis; Vitamin D.

Figures

Fig. 1

Vitamin D3 supplementation increases serum 25-OH vitamin D and does not impact serum calcium or lung function. a) Vitamin D levels increased over the 24 weeks of supplementation but were only significantly higher between day 0 and the 24-week time point. b) Serum calcium levels did not change significantly over the 24-week trial period. c) Urine calcium:creatinine ratios increased slightly over 24-weeks and were significantly higher between day 0 and 24-weeks. Data is graphed as for each individual patient at each time point P

Fig. 2

Vitamin D supplementation decreases Aspergillus induced IL-13 responses in CD4+ T cells. CD11c + DCs with from patients with confirmed ABPA before (D0) and 8 and 24 weeks after 4000 IU cholecalciferol daily were treated with a) media or b) TSLP (5 ng/ml) and then pulsed with Aspergillus extract. Purified CD4+ T-cells were added for 96 h. Supernatants were harvested and analyzed by Luminex for IL-13 production. Data is graphed as a percentage of the stimulated response (CD3/CD28) for each individual patient at each time point

Fig. 3

Blockade of TGFβ or IL-10 signaling does not reverse vitamin D mediated IL-13 cytokine production. CD11c + DCs with from patients with confirmed ABPA before (D0) and after supplementation with 4000 IU cholecalciferol daily were treated with a and c) media or b and d) TSLP (5 ng/ml) and then pulsed with Aspergillus Extract followed by addition of allogeneic bulk CD4+ T-cells followed by addition of a and b) sTGF-βII/FC (10 μg/mL) or c and d) anti-IL-10 (1 μg/mL). Cells were incubated for 96 h and IL-13 was measured in cell supernatants by Luminex. Data is graphed as a percentage of the stimulated response (CD3/CD28) for each individual patient at each time point

Fig. 4

Effect of vitamin D on IgE and Aspergillus specific IgE. Daily vitamin D supplementation did not affect total IgE levels over a 24 week period (a) but vitamin D treatment significantly decreased Aspergillus specific IgE over 8 weeks and 24 weeks (b)

Fig. 5

Vitamin D supplementation decreases A. fumigatus specific Th2 response. CD11c + DCs with from patients with confirmed ABPA before and 8 and 24 weeks after supplementation with 4000 IU cholecalciferol daily (n = 7) were treated with a) media or b) TSLP (5 ng/ml) and then pulsed with Aspergillus Extract. Purified CD4+ T-cells were added for 96 h. Supernatants were harvested and analyzed by Luminex for IL-5 production. Data is graphed as a percentage of the stimulated response (CD3/CD28) for each individual patient at each time point)