Product Questions

Q. Are the quantities of components provided in the kit enough? Is anything else required?
A. Yes, we provide more than enough of all components to run the entire plate once.  Except the usual equipment to run an ELISA test (pipettes, plate reader etc), no other materials or special equipment is required to run the kit.

Q. Is it absolutely necessary to test in doubles?
A. Due to the clinical impact of the results, we strongly recommend testing in duplicates.  However, if a lab has proven robustness between duplicates, the assay can then be run in singlets to provide 78 tests per plate. Robustness between duplicates is achieved through pipetting and washing accuracy, thus determined by the technical expertise of the testing lab – please refer to our detailed guide to running a suPARnostic® kit successfully.

Q. Can we freeze the kit to make it last longer?
A. The shelf life of all the components, except the HRP conjugate, is many years. The activity level of the HRP conjugate, which determines the expiry date, will start to decline after the expiry date. Freezing of the conjugate eliminates this problem and extends shelf life by many months.

Q. Do you have an FDA approval? Will you get one?
A. We do not have an FDA approval yet, but will apply for it.  We are CE/IVD marked and for our product that is enough to be able to sell in Europe and many other markets.

Q. There is not enough clinical proof to use this.
A. We continue to demonstrate the value of suPAR with studies and trials that only serve to provide repeatedly consistent results.  Over 115 papers have been published on this matter. 

Q. I use the R&D/AD suPAR kit.  Why switch?
A. Most importantly, R&D/AD kits cannot be used for clinical purpose; theirs are only research kits and  offer no comparability of results. Also, we alone own the necessary patents. In terms of usability and results, the suPARnostic® kit is far superior.

Q. How long after removal from refrigeration can I use the kit?
A. For up to 3-4 hours.  The kit only needs to be kept at room temperature for about 30 mins. before use.

Q. Can all blood types be used to measure suPAR?
A. Yes, any blood type can be used to measure suPAR.

Q. What if the plasma samples used to measure suPAR were left unrefigerated?
A. We have conducted bench tests where we left plasma at room temperature for a week.  There was no deterioration in the suPAR levels in the blood.  So yes, for plasma not refrigerated for up to one week, suPAR levels will not be affected.

Q. Do I need venous or arterial blood?
A. Venous blood. No arterial blood is required.

Scientific Questions

Q. This test is too general – it is prognostic in so many indications so how can I use it for a specific one?
A. Yes, suPAR is prognostic in many different indications. What is important is how it is used.  We have clinical proof in each of the three indications and from this data we have developed unique clinical and monitoring guidelines tailored to each indication. 
So, for a doctor using suPARnostic® in TB e.g. – we will recommend it be used only for treatment efficacy monitoring. 
Q. What about a patient who has multiple infections – HIV+TB.  That is quite common.  What will his suPAR level be then because suPAR is prognostic for both these indications?A. This is a good question.  Very simply, no doctor would ever make any clinical decision in such serious conditions based solely on the results of our, or any other single tests. Doctors always make decisions using their knowledge of clinical symptoms in combination with a range of tests. A serious double infection like TB+HIV will warrant the use of several available tests. The suPAR level is a decision-making aid, not a decision itself.

Q. Sputum culturing gives good enough results in TB– why use this?
A. Sputum culture is a long, cumbersome and sometimes expensive process.  Also, one has to wait months after medication has begun to check whether it is effective.  suPARnostic® thus provides the following advantages over sputum culturing: 
1. A single test with results in 2-3 hours 
2. Simple and easy on the patient – just one blood sample required 
3. Provides an accurate picture of treatment efficacy within 4 weeks of treatment

Q. I’m happy using CD4 and Viral Load.  There is no need for suPARnostic®.
A. suPARnostic® is a replacement for expensive and complicated Viral Load tests, not for the CD4 test.  In fact we provide the best results when used in conjunction with the CD4 test. In an ideal setting suPAR adds a third, independent parameter. 
We have published numerous papers which compare the results of CD4, Viral Load and suPAR.  
For more information about the findings, please look under Documentation - Publications 

Q. CRP provides similar information and is a well established test.  Why should I use this?
A. Three reasons for this: 
1. Most importantly, there is NO correlation between suPAR and CRP results.  In sepsis suPAR is much more accurate than CRP and can catch patients that CRP will often miss. 
2. CRP is unpredictable – it rises just because an individual may be physically stressed with no sign of an infection.  We will not provide such ’false positives’ – suPAR levels are only affected by infections and inflammation, not by short term life circumstances and other common ailments (e.g. the flu). 
3. suPARnostic® is an early and very strong predictor of mortality – CRP is not

Q. How quickly does a patient’s suPAR level respond to SIRS or sepsis?
A. The observation in trials tells us it is very quick, within a couple of hours.  A patient’s suPAR level continues to rise as the infection gets more serious. So, an upward trend is seen in slowly worsening conditions.

Q. Can suPARnostic® be used on infants or pregnant women?
A. suPARnostic® can be safely used on pregnant women.  It cannot be used on infants.

Q. Can someone have a naturally high suPAR level?A. No, no genetic polymorphisms exist that cause humans to express naturally high suPAR levels.  A high suPAR level relates to an infection or inflammation of some kind.

Explanation of Used Terms

Angiogenesis : Process involving the growth of new blood vessels from pre-  existing vessels.

Biomarker : A biomarker is a substance used as an indicator of normal biologic processes, pathogenic processes, or pharmacologic responses to a therapeutic intervention.

Domain : Small defined part of a protein. suPAR consists of three similar domains; DI, DII and DIII.

Hydrophilic : From the Greek (hydros) "water" and (philia) "friendship". A molecule that are soluble in water (Antonym: Hydrophobic). suPAR is hydrophilic and therefore soluble.

Hydrophobic : From the Greek (hydros) "water" and (phobic) "fear". A molecule that is repelled by water (Antonym: Hydrophilic).

Inflammation : The immune response of an organism to a pathogen.

Integrins : Integrin plays a role in the attachment of cells to other cells and also in signal transduction.

In vitro : (Latin for within the glass) refers to the technique of performing a given procedure in a controlled environment outside of a living organism (Antonym: In vivo)

Ligand : Molecule that are bound by other molecules. uPA is a ligand of uPAR (see Receptor)

Membrane : The membrane of a cell is the interface between the cellular machinery inside the cell and the fluid outside.

Protein : Biological molecule made out of chains of amino acids

Proteolysis  : Degradation of a protein by other molecules.

Proliferation  : Refers to cell growth, development and division.

Receptor : Molecule that binds another molecule (ligand). uPAR is receptor for uPA (see Ligand).

ROC : Graphical plot of the sensitivity vs. (1 - specificity). Used in order to compare two or more different methods.

Scavenger(biochemical) : Molecule that binds substrates of other molecules. suPAR can bind uPA which is ligand of uPAR.