Levels of cytokines and chemokines were analyzed after log transformation and a value of 0.2 pg/ml was used in the case of undetectable concentration of cytokine or chemokine in the tested samples. The Mann-Whitney U or Fisher exact tests were used for group comparisons of numerical and categorical data respectively. For all analyses, a P value of less than 0.05 derived from a two tailed test was considered significant. All statistical analyses were performed with 'SPSS11.0 for Windows' software (SPSS Inc.).