Serum Cathelicidin Concentrations in Healthy Rural Indian School Going Children

Excerpt

To the Editor: High levels of Cathelicidins are indicative of response to infection which is mediated by Vitamin-D concentrations. In a cascade response, Vitamin-D enhances immune response to produce Cathelicidins which help to kill intracellular bacteria. Thus, levels of Cathelicidins are enhanced in infectious diseases [1]. The aims of our pilot study were to assess serum Cathelicidin concentrations among healthy rural Indian children and to study association of Cathelicidin concentrations with age, gender, body composition (BC- Fat percentage) and 25-(OH)D concentrations. Standard protocols were used for data collection including demography, anthropometry and blood assessments [hemogram and serum 25-(OH)D]. Ninety-four children (mean age 9.3 ± 0.8 y, range 7.5 to 11 y, 46 boys) were assessed for anthropometry and biochemical parameters. Height, weight and BMI- Z scores were computed using reference data. Boys and girls were similar in anthropometry (p < 0.1) except body fat % which was significantly higher in girls (7.9 ± 7.1% vs. 11.9 ± 7.1% respectively, p = 0.008). Biochemical parameters [hemoglobin, white blood cell count (WBC) and serum 25-(OH)D] were also similar among boys and girls except serum Cathelicidins. Significantly higher concentrations of circulating Cathelicidin were observed in boys as compared to girls (p = 0.02). Mean Cathelicidin concentrations in boys were 99.8 ± 37.7 ng/ml (range 52.6 to 253.8 ng/ml) and in girls were 83.8 ± 24.9 ng/ml (range 48.2 to 174.3 ng/ml). No associations were observed between serum Cathelicidins and 25-(OH)D concentration, WBC counts or growth-parameters (HAZ/ WAZ/ BAZ). Linear regression analysis indicated that age and gender were positively associated with serum Cathelicidin concentrations (β = 0.127, SE- 0.33, p = 0.038 and β = 0.254, SE- 0.48, p = 0.032 respectively), whereas 25-(OH)D levels and fat % showed no association with serum Cathelicidin. Stukes et al. have also reported similar observations among healthy young children (age 2–7 y), where they observed higher levels of Cathelicidins with increasing age and no association of Cathelicidin with Vitamin-D concentrations [2]. Positive correlation of Cathelicidins with increasing age has also been reported by other studies [2, 3]. On the contrary, adults show decrease in immune function with increasing age [1]. Being a Sun rich country, majority of our rural children were Vitamin-D sufficient (>80%, >20 ng/ml), [4], this may be one of the reasons why we found no association between 25-(OH)D and Cathelicidins. Further, as our population was healthy, WBC counts and BMI were within the reference range for most children; no association of these parameters was found with Cathelicidins in our study participants. Similar observations have also been reported in adults [5]. …