Thursday, 24 May 2012

CHARGE, you give me fever

The recent passing away of Robin Gibb is a sad loss to the music world. The falsetto tones of the Bee Gees made them one of the most instantly recognisable groups with their string of hits worldwide. Many of their best loved songs were part and parcel of the film 'Saturday Night Fever' in which John Travolta single-handedly shaped a disco generation mirroring millions of male preparations for that Saturday disco odyssey. Move over Disco Stu.

Fever of another sort has also been making news of late with specific reference to autism or more precisely to the offspring risk of autism spectrum conditions in mums-to-be reporting fever or the more scientific term pyrexia (I assume from the Greek to mean fire). The paper in question is this one by Zerbo and colleagues* reporting yet more results from the CHARGE initiative and their cleverly worded website 'beincharge'.

I'm not going to give this paper the mega-post treatment but a few details are noteworthy:

  • Data for upwards of 500 children diagnosed with an autism spectrum condition were compared with that from children with a developmental delay (n=163) and asymptomatic controls (n=421). Such data for this paper included quite a bit of information around pregnancy in terms of mum's report of illness, fever and medications taken during the mum-to-be period.
  • No significant link was found between either reports of maternal influenza or flu vaccination during pregnancy and subsequent offspring autism. When it came to asking about fever during pregnancy, this was a slightly different story as the odds ratios show (OR = 2.12 CI: 1.17-3.84) where offspring autism was over twice as likely to be present in mums reporting fever during pregnancy. Having said that the OR was even greater for those children diagnosed with developmental delays (OR = 2.5 CI: 1.2-5.2).
  • Self-medicating for fever during pregnancy using antipyretics such as ibuprofen or paracetamol (acetaminophen) seemed to be associated with a reduction in the risk of offspring autism.

OK let's take a step back before we get too readily involved in these findings. CHARGE whilst being a good starting point for ascertaining any potential environmental links to autism is still very much a preliminary attempt to look at any associations. Asking about fevers retrospectively is a good idea but still open to some degree of bias. Nine months pregnancy, equivalent to about 280 days, is quite a long time period to look into retrospectively. This is aside from the fact that one person's fever might be another person's 'off-day' and as for medication practices over that time, particularly self-medication (presumably OTC not requiring a prescription) ... I'll leave you to decide on potential accuracy.

Having said all that there are some potential nuggets of information to be derived from this study. Inflammation and those dastardly proinflammatory cytokines are a pretty well recognised feature of at least some cases of autism. I'm not necessarily saying that they are causative or anything like that, but some clues seem to be attached to such findings. I seem to remember some findings from not so long ago in relation to MET and autism attached to the CHARGE study which may very well tie into this latest offering and in particular, lower levels of the anti-inflammatory cytokine IL-10 among other things.

CHARGE has also suggested quite a few other potential associations between pregnancy and risk of offspring autism including: obesity, vits and SNPs, and living next to a motorway (freeway). I would be very interested in seeing some grand analysis of all of these factors published by the CHARGE team just to see how all these various elements might tie together. Even based on each individual participants throughout the various studies, one gets the impression that there is some valuable data to be mined from the initiative pertinent to the formulation of more prospective trials.

To finish, some associated clips to relive those Halcyon days of Boogie.

* Zerbo O. et al. Is maternal influenza or fever during pregnancy associated with autism or developmental delays? Results from the CHARGE (CHildhood Autism Risks from Genetics and Environment) study. JADD. May 2012.