Killer Cell Immunoglobulin-like Receptor Genotype and Haplotype Investigation of Natural Killer Cell

Fresh from Griffith University:

Killer Cell Immunoglobulin-like Receptor Genotype and Haplotype Investigation of Natural Killer Cells from an Australian Population of Chronic Fatigue Syndrome/Myalgic Encephalomyelitis Patients
t. K. Huth1,2, e. W. Brenu1,2, d. R. Staines1,2 and S. m. marshall-Gradisnik1,2

Received: April 04, 2016. Resubmitted: May 04, 2016. Accepted for Publication: May 05, 2016

Open access

http://www.la-press.com/killer-cell...r-genotype-and-haplotype-invest-article-a5702

Abstract
Killer cell immunoglobulin-like receptor (KIR) genes encode for activating and inhibitory surface receptors, which are correlated with the regulation of Natural Killer (NK) cell cytotoxic activity.

Reduced NK cell cytotoxic activity has been consistently reported in Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME) patients, and KIR haplotypes and allelic polymorphism remain to be investigated.

The aim of this article was to conduct a pilot study to examine KIR genotypes, haplotypes, and allelic polymorphism in CFS/ME patients and nonfatigued controls (NFCs).

Comparison of KIR and allelic polymorphism frequencies revealed no significant differences between 20 CFS/ME patients and 20 NFCs. A lower frequency of the telomeric A/B motif (P < 0.05) was observed in CFS/ME patients compared with NFCs.

This pilot study is the first to report the differences in the frequency of KIR on the telomeric A/B motif in CFS/ME patients.

Further studies with a larger CFS/ME cohort are required to validate these results

 

Here is the full PDF http://www.la-press.com/redirect_fi...enotype-and-Haplotype-Invest.pdf&fileType=pdf

 

The link was also on my original post...

 

Can anyone translate?

 

That is the abstract

 

It seems to me that there is a genetic defect on the gene that transmits signals from NK cells. Don't quote me on that though. I am still crashed and my brain hurts from presenting to my MP on Friday. Reading this paper was too much for my brain.
They were using a Fukuda cohort, and excluding patients woth other diseases including depression but it was not noted that all of them had PEM.

 

Tha main finding appears t be that there was no difference between ME/CFS and controls. They mention a different frequency of haplotype heterozygosity (A/B) but they do not give a figure for it. I am not sure what it would mean,

There has been a previous paper suggesting a difference in KIR expression in ME/CFS - which this paper does not seem to confirm. The sample is too small to be decisive but it would be useful to establish that there is no genetic difference in KIRs and move on from that option to another hypothesis. The pity is that people do not realise just how important negative findings are and often do not even publish them.

 

It looks like they didn't find any significant differences between patients and controls regarding the frequency of single SNPs, nor even on the same gene. The impression I'm getting is that they came up with a convoluted category of various SNPs for a group of genes, combined them into arbitrary "motifs", and found the heterozyous form of one motif to be less common in ME patients than in the controls.

There's no indication that there were corrections for making multiple comparisons, meaning that even the "significant" result was not significant at all. And basically they could have rearranged the motifs until something nominally significant popped up. Which is a pretty crappy way to do things.

It's also a red flag when it's the heterozygous version of a genotype or haplotype which is supposedly the significant one. If a genotype or haplotype is causing problems, it should be a homozygous one which is the most problematic.