Serum periostin levels in adults of Chinese descent: an observational study

Periostin has been shown to be a marker of Type 2 airway inflammation, associated with airway eosinophilia. It has a potential role in identifying asthmatics who may be responsive to treatment with monoclonal antibody therapy directed against Type 2 cytokines, such as interleukin (IL)-13, IL-4 receptor subunit-α and immunoglobulin E. The clinical utility of periostin measurements depends on better understanding of factors that may affect serum periostin levels, such as race. We aimed to identify the ranges of serum periostin in Chinese adults both with and without asthma, and compare them with those previously identified in Caucasian adults.

A two-centred cross-sectional study, recruiting 188 Chinese adults, aged 18 to 75 years. 120 participants had no history of asthma or chronic obstructive pulmonary disease. 68 participants had a doctor's diagnosis of asthma and were on current treatment. Univariate comparisons of periostin by dichotomous variables were made using t-tests with logarithmic transformation as the distribution of periostin was skewed.

In the Chinese non-asthma group, periostin levels were sex-, but not age-dependent, with females having higher periostin levels. The individual predicted (90% CI) reference range for periostin in females was 61.1 ng/ml (41.6 to 89.8) ng/ml and in males was 53.2 ng/ml (36.1 to 78.3) ng/ml. There was no difference in median serum periostin levels between Chinese non-asthmatics and Chinese asthmatics, 57.0 versus 56.8 ng/ml, difference (95% CI) 0.1 (- 4.2 to 4.2) ng/ml, P = 0.94. The median serum periostin levels were higher in Chinese non-asthmatics than Caucasian non-asthmatics, 57.0 versus 49.7 ng/ml, difference (95% CI) 8.2 (5.8-10.6) ng/ml, P < 0.001.

Serum periostin does not discriminate between asthmatics and non-asthmatics and is therefore not a good biomarker to diagnose asthma. Serum periostin levels were higher in the Chinese compared to the Caucasian non-asthma group, and also sex dependent in the Chinese participants. There was no difference in serum periostin levels between Chinese non-asthma and asthma groups. This suggests that ethnicity should be considered in the interpretation of periostin levels in asthma patients and sex is an additional consideration in Chinese patients.Trial registration This trial was prospectively registered with Australian New Zealand Clinical Trials Registry (ACTRN12614000122651).