Background
Vitamin D plays an important role in inflammatory responses after antigen exposure. Interleukin-23 (Il-23) promotes Il-17-dependent inflammation during
Pseudomonas aeruginosa (P. aeruginosa)
pulmonary infection. We aimed to compare the ability of calcitriol and cholecalciferol to modulate the inflammatory response of the CF airways infected with
P. aeruginosa.
Methods
This was a randomized, placebo-controlled, double-blind, cross-over trial. Twenty-three patients with CF (aged 6–19), chronically infected by
P. aeruginosa
were randomly assigned to:
calcitriol group
receiving 1,25(OH)
2
D 0,5 mcg daily or
cholecalciferol group
receiving cholecalciferol 1000 IU daily for three months. The levels of Il-23 and Il-17A in the exhaled breath concentrate (EBC) were measured. Calcium-phosphorus balance was also evaluated (serum concentration of calcium, phosphorus, 25OHD, parathormone (PTH) and calcium/creatinine ratio in urine). Data were analyzed using means of Stata/Special Edition, release 14.2. A level of
P
< 0.05 was considered statistically significant.
Results
The level of Il-17A in EBC significantly decreased in
calcitriol group
from 0,475 pg/mL (± SD 0,515 pg/mL) to 0,384 pg/mL (± SD 0,429 pg/mL) (
p = 0,008
); there was no change in
cholecalciferol group
(
p = 0,074
). The level of Il-23 in EBC did not significantly change in
calcitriol group
(
p = 0,086
); there was significant decrease in
cholecalciferol group
from 8,90 pg/mL (± SD 4,07 pg/mL) to 7,33 pg/mL (± SD 3,88 pg/mL) (
p = 0,001
). In
calcitriol group
serum phosphorus and PTH significantly decreased (
p = 0,021 and p = 0,019
respectively), the concentration of calcium significantly increased (
p = 0,001
); there were no changes in
cholecalciferol group
.
Conclusions
Both analogs of vitamin D revealed their anti-inflammatory effect and reduced the level of Il-17A and Il-23 in the airway of CF patients with chronic
P. aeruginosa
infection. We observed improvement in calcium-phosphorus metabolism after supplementation with calcitriol, without adverse effects. It is recommended to use vitamin D in CF patients.
