Why measure mRNA in blood?
Feel free to tell me to go read a few papers if you think this is a ridiculous question.
I'm currently measuring mRNA in whole blood using RT-qPCR, whole blood ideally contains red blood cells, white blood cells, plasma, platelets along with other complexes that are stable in the circulation.
When you measure mRNA in whole blood are you only detecting the mRNAs that are present in white and red blood cells, have the rest not degraded?
I'm aware that microRNA and other small non-coding RNA complexes can exist in the circulation in exosomes and attached to HDL-proteins, but when you measure mRNA in blood are they really telling you anything unless your pathology directly relates to red or white blood cells?