Serum Clara cell protein and atopic phenotype in children up to 2 years of age.

BACKGROUND

Low value of serum Clara cell protein (CC16) is associated with bronchial hyperreactivity in children.

OBJECTIVE

To evaluate the serum CC16 in relation to atopy and previously manifested LRTD.

METHODS

In the population of 163 healthy 5- to 24-month-old children, atopy was determined by Phadiatop-infant (serum-specific IgE≥0.35 kUA/L), serum CC16 by ELISA, while data on previously manifested low respiratory tract diseases (LRTD) were collected from the Health Care Center database.

RESULTS

In atopic children, serum CC16 negatively correlated with age (r -.281, P=.041, n=53), while in nonatopic children, this correlation was positive (r .200, P=.036, n=110). Atopic ≥8-month-old children with previously manifested LRTD had lower level of CC16 (3.07 ng/mL) in relation to atopic children without LRTD at the same age (6.51 ng/mL), P=.029 (value of serum CC16≥4.8 ng/mL indicates atopic phenotype without LRTD 75% sensitivity, 87.5% specificity). In 8- to 24-month-old children with previously manifested pneumonia, serum CC16 was lower in atopic (2.9 ng/mL) in relation to nonatopic children (3.7 ng/mL), P=.029 (serum CC16 ≤3.4 ng/mL indicating atopy in the group of children with pneumonia, sensitivity 100%, and specificity 77%). Atopic 8- to 24-month-old children with previously manifested pneumonia had lower CC16 in relation to other atopic children in this age (P=.021) (for cutoff CC16≤3.4 ng/mL sensitivity 100%, specificity 77%), and also often chronic wheezing (atopic with pneumonia 83.3%, n=5/6 vs atopic without pneumonia 21.4%, n=3/14), P=.018.

CONCLUSION

Low serum CC16 is associated with previously expressed pneumonia and chronic wheezing in atopic children.