It looks like those Toll-like receptors may indeed be important. I included a review article in a previous Neonatal Updates, which was nice introduction to these transmembrane receptors that are important in immune responses. A new article suggests that variants in Toll-like receptors are important in determining susceptibility to sepsis. Out of 408 very low birth weight babies, the 90 that developed infections had a different profile of the SNPs of their TLRs than those that did not.
Sampath V, Mulrooney NP, Garland JS, He J, Patel AL, Cohen JD, et al. Toll-like receptor genetic variants are associated with Gram-negative infections in VLBW infants. J Perinatol. 2013 Jul 18..
I hope that sounds like I understand all this stuff, I like sounding well-informed!
If you read this blog, (and I guess if you are reading this blog you are a reader of this blog….) you know I will often be rather skeptical, so I would say for this study that the results are preliminary, that if you look for associations between 9 different SNPs and infection you might well find some that turn out to be spurious in the future; however, these authors did apply a Bonferroni correction for multiple statistical testing and it seems plausible that if the SNPs affect TLR function there could well be effects on sepsis susceptibility. Confirmatory studies will I am sure be forthcoming.
The next question is what to do with this information? Sepsis in very preterm babies is very important; it is frequent, and leads to long term disability, cognitive and motor (free access). The NICHD network published a long term follow up of infants with Candida and other septic episodes earlier this year (the first author is my friend and previously a fellow from when I was in San Diego: great study Ira!) This article confirms what we knew about late onset sepsis and adds much new information about the long term effects of Candida.
So if we can somehow in the future use the understanding of TLR variants and sepsis susceptibility to find ways to reduce sepsis then we may have a big impact on the lives of our patients.