Statistical analysis.  Genotype frequencies PI3K inhibitor were determined by direct counting of the individual positive for a particular KIR phenotype specificity. Chi square was used to test for statistical significance of the genotypes or haplotypes between the patients and controls. P values < 0.05 were regarded as statistically significant. The strength of association was estimated by calculating the odds ratio (OR) and 95% confidence interval (95% CI). Statistical analysis was carried out using the spss 13.0 software package (IBM Corporation, West Harrison, NY, USA). All the tested KIR genes were present in different frequencies in control

and patient groups in this study. Framework genes KIR2DL4, KIR3DL2, KIR3DL3 and KIR3DP1 were present in all individuals. All KIR genotypes and haplotypes were determined in this study according to the model described by Hsu et al. [4]. In this study, we found 25 genotypes, including 11 new genotypes of NF1∼NF11, which had not been observed in Caucasians so far [4]. Among these genotypes, 21 were determined in healthy controls, and 22 in patients with syphilis (Table 2). In healthy controls, three genotypes with higher frequency in

rank order were AJ (34.90%), P (14.06%) and AH (10.42%). In patients RAD001 clinical trial with syphilis, the genotypes AJ (28.95%), AH (14.2%) and AF (10.00%) were three higher genotypes. Of interesting, the frequencies of genotype AE and AG were higher in patients with syphilis than those in healthy controls (P = 0.020 and P = 0.041, respectively), while the frequency of genotype P was lower in patients with syphilis than that in healthy controls (P = 0.002) and its OR was 0.304. The other KIR genotypes did not show significantly different distribution in the two groups. According to previous description [4], the genotypes P and AE contain combinations of haplotype 2 and 17 and haplotype 1 and 6, respectively, while genotype AG contains combination of homozygous haplotype 1. Next, we reanalysed the distribution of KIR haplotype in both patients

with syphilis and controls. In this study, all the 25 genotypes could be resolved into corresponding pairs of haplotypes as shown in Table 3. Both healthy controls and patients with syphilis had 17 different haplotypes. Haplotype 2 was the most frequent, followed by haplotype 1 and 5 in the two groups. Interestingly, the frequencies of haplotype Adenosine 1 and 6 were lower in healthy controls than those in patients with syphilis, while the frequency of haplotype 17 was higher in healthy controls compared with that in patients with syphilis, and its OR was 0.321. The other KIR haplotypes did not show significantly different distribution in the two groups. All haplotypes mentioned earlier belong to either haplotype A or haplotype B. The frequencies of haplotype A and B were shown in Table 4. The frequency of haplotype A was higher than that of haplotype B in both healthy controls and patients with syphilis.