EBV viral load measurement:
From patient to interpretation in transplant recipients
To progress with EBV viral load standardization we ask you today to share your experience about EBV viral load testing in transplant recipients with us. In order to summarize all data we have set up a semi-standardized questionnaire. Please feel free to add any comment you feel that might be important. We do not only ask how you are performing EBV viral load measurement but also why you choose this or that method. Selecting one or the other method might be a result of
- theoretical reasons
- data from others (e.g. literature, expert opinion)
- own experience
- other reasons
We would be very thankful if you could indicate which reason was relevant for you. Moreover, it would be great if you could specify the reasons e.g. if you tested different methods and as a result selected one method it would be excellent if you could give more detailed information about your evaluations. If you feel that this is too time consuming at the moment we would be happy if we could contact you again and ask for details for certain questions.
Performing viral load measurement in a certain way does not necessarily mean that this is the methods you prefer as a standard. Thus, for some topics we ask separately what you preferand why.
We know that you will need some time to answer all theses questions, but we think that this is the only way to combine all our experience about EBV viral load measurement to find a consensus. When we publish the consensus all who answered the questionnaire are co-authors. To help you with filling out this form you find here the questionnaire and the answers of one lab.
Thank you very much for your help!
Name
Address
Phone
Fax
1.)Patients
Could you describe the patients you are testing for EBV viral load (e.g. how many solid organ transplant recipients (which organs), stem cell transplant recipients, adults, children)?
Over all how many EBV PCRs do you perform per week (all EBV PCRs not only the PCRs for transplant recipients?
How often (per week) do you perform EBV PCR?
2.)Sampling
How often do you test the patients in routine? Are the intervals different according to age of the patients for solid organ recipients or for stem cell transplant recipients? Are the intervals different for adults and for children? On what are the intervals depending?
Please select a reason why you choose these intervals.
Could you please specify your reasons?
3.)Matrix
Which matrix do you use for testing other than blood (e.g. CSF, biopsies)?
If you test blood, which matrix do you use (serum, plasma, whole blood, PBMC, B cells a.s.o.)?
Please select a reason why you choose this sample matrix.
Could you please specify your reasons?
What would you prefer for a standard material?
4.)Extraction
Which method do you use for extraction?
Please select a reason why you choose this extraction method.
Could you please specify your reasons?
Do you think we should standardize the extraction? If yes, what would you prefer?
5.)PCR-technique
- Technique
Which PCR technique are you using?
Please select why you choose this method?
Could you please specify your reasons?
- Location of primer and probes
Where in the EBV genome are your primers and probes located?
Please select why you choose this location?
Could you please specify your reasons?
What genome location would you prefer as a standard?
- Length of fragment
How long is your PCR fragment?
- Method of quantification
Which method do you use for quantification?
Please select why you choose this method?
Could you please specify your reasons?
What would you prefer as method for quantification?
- Standards
What are you using as a standard for quantification in your assay (e.g. plasmid, Namalwa, diluted in what?
Please select why you choose these standards.
Could you please specify your reasons?
.
What do you prefer as a standard and why?
- Inhibition control
Do you use inhibition controls, if yes, which controls?
Please select why you choose this method.
Could you please specify your reasons?
- Unit
In which units do you report your results, if you use more than one unit please indicate.
Please select why you choose this units.
Could you please specify your reasons?
Which units do you prefer and why?
6.)Interpretation
For which aims are you using viral load detection in transplant recipients? (Please tick the box, you can tick more than one box).
diagnosis of PTLD
preemptive therapy
to guide immunosuppression
other reasons
- Cut-off or dynamic
Did you establish a cut-off for one these aims, if yes please indicate the cut-off in the table? If in addition (or only) the dynamic of the increase in viral load is relevant please indicate in the table the increase in log (during which time) which is relevant for your decision.
Aim / Cut-off / Dynamic (in log)Diagnosis of PTLD
Preemptive therapy
Immunosuppression
other
If the table does not fit to your decision tree please explain?
- Which other methods (EBV detection) are relevant for you when interpreting the viral load (e.g. EBV specific T cells, EBV mRNA?)
- Which other factors (e.g. age of patients, time after transplantion a.s.o.) are important for you in interpretation of a viral load?
7.)Comments
Do you have any comments?
Many thanks for your help