I have been given mock results from a PCR test on blood samples taken from kidney recipient patients and their donors. The PCR reaction can detect single copies of viral DNA. I have been asked to determine whether 5 patients have been infected with either human herpesvirus 6 (HHV6) or human cytomegalovirus (HCMV) following kidney transplants. I have results for patients pre-transplantation and 1/3 weeks post-transplantation.
The results are as follows:
- Donor for patient A = HCMV+
- Donor for patient B = HCMV+ & HHV6+
- Donor for patient C = Neg for both viruses
- Donor for patient D = HHV6+
- Donor for patient E = HCMV+ & HHV6+
- Patient A = HCMV+ before and 1 & 3 weeks post-transplant
- Patient B = Neg for both viruses before, then HHV6+ at week 1 & HCMV+ at week 3 following transplantation but negative for HHV6.
- Patient C = HHV6+ before and 1 & 3 weeks post-transplant.
- Patient D = HCMV+ before and HCMV+ & HHV6+ 1 & 3 weeks post-transplant
- Patient E = HHV6+ before and HCMV+ & HHV6+ 1 & 3 weeks post-transplant
Answers: I am guessing that Patient A was re-infected by donor A. Patient B was neg for both viruses, developed HHV6 week 1 but this test was neg week 3 & instead positive for HCMV – these viruses do not disappear, you either have it or don’t so assuming there is no contamination error then what virus did he develop post-transplant?? Patient C was HHV6+ prior to transplant but donor is neg for both, so what virus did he develop following transplant? I can see that Patient D was infected with HHV6 from donor post-transplant. Patient E was infected with HCMV from donor post-transplant.
I am struggling to determine what virus Patient A, B and C was infected with following transplant. Can anyone help? I know almost 100% of us are infected with both viruses but do not cause disease in healthy people, that both latent and active viruses show positive when in blood and that both viruses can re-activate under certain conditions such as via infected organ transplants and immunosuppression.