Can BK Virus serum PCR be a good marker for Net immunosuppression?

In the field of transplantation, we are struggling to figure out is the patient on which end of the spectrum, too little immunosuppresion or too much immunosuppression.  Markers for rejection have been studied extensively and based on Luminex DSA one can monitor early signs of impending antibody rejection.  But many centers are also developing aggressive screening strategies for BK Nephritis.  This entity is usually seen as early as 2 weeks post transplant to as late as 7 years post transplant but usually in the first year or so.

I think that A BK serum PCR might be a good marker for NET immunosuppression. Someone who has lupus and has been treated with Cytoxan, Cellcept, Rituxan and has failed kidneys recently and then gets a transplant for the kidney and gets inducted with more immunosuppression might be the highest risk for BK Nephritis much earlier on due to their NET immunosuppresion being the highest. No one can really measure NET immunsuppression.  There is a test available called " Cylex" or ImmuKnow . This  is the physiology behind it:  

"Phytohemagglutinin (PHA) is a non‐specific mitogen which can be used to stimulate cell division in CD4 T‐ lymphocytes regardless of their antigenic specificity or memory status. Therefore, PHA is considered to be a “global” stimulator of the immune system. The production of intracellular ATP is one of the first steps in cellular activation following stimulation with mitogens such as PHA.  ATP is a multifunctional nucleotide which plays an indispensible role in the transfer of intracellular chemical energy. The amount of ATP generated can tell us the amount of CD4 T cell activation and the overall immune status of the patient( over or under immunosuppressed). " -from the cylex website( summarized) 

But a cell activation can occur in setting on an infection as well and a similar down stream effect on the kidney. Steady monitoring of infectious agents like BKV might be the BEST marker we have to date to tell us " Hey there is too much immunosuppression on board" !

But might not be as simple as that...

Lets see what future studies hold...

http://www.ncbi.nlm.nih.gov/pubmed/20723175

http://www.cylex.net/