Comparison of cytokine gene polymorphisms among Greek patients with invasive meningococcal disease or viral meningitis

High levels of pro-inflammatory cytokines are implicated in the severity of invasive meningococcal disease (IMD) and viral meningitis (VM). This study compared single-nucleotide polymorphisms (SNPs) in pro- and anti-inflammatory cytokine genes among patients with VM or IMD. Patient DNA samples were prepared by the National Meningitis Reference Laboratory in Athens: n = 98 for IMD and n = 53 for VM. The results for both patient groups were compared with data published for healthy Greek control data. Real-time PCR was used to assess the interleukin (IL) gene SNPs IL6 G−174C, IL1B C−511T, IL1RN T+2018C, IL10 G−1082A and IL8 A−251T and the tumour necrosis factor α (TNF-α) SNP TNFA G−308A. Differences were compared by Fisher’s exact test. The genotype for high IL-6 responses was predominant among IMD (51 %, P = 0.0008) and VM (74.5 %, P<0.0001) patients compared with the controls (31 %). The genotype associated with high TNF-α responses was 5 % among controls and lower for IMD (1.1 %, P = 0.0014) and VM (0 %, P = 0.052). There was no difference for IL-8 SNPs between controls and IMD (P = 0.162), but the difference was significant for VM (P = 0.0025). IL-6 (P = 0.024) and IL-8 (P = 0.00004) SNPs differed between IMD and VM. Reports on associations between IL-8 SNPs and cytokine responses differ. Because of its role in neutrophil attraction, differences in frequencies of the IL-8 SNP for IMD and VM require further investigation.