Evaluation of the QuantiFERON- CMV assay as a monitoring tool in solid organ and allogenic stem cell transplantation

Transcription

1 Evaluation of the QuantiFERON- CMV assay as a monitoring tool in solid organ and allogenic stem cell transplantation Dr Grace Thompson A/Prof Mina John

2 CMV in transplantation Major cause of morbidity and occasional mortality post transplantation Fernandez-Ruiz, Transplant International 2015

3 Known risk factors Eg CMV antibody status, immunosuppression Limited tests to help predict: Late reactivation of CMV Duration of prophylaxis Frequency of viral load monitoring Requirements for treatment in low level viraemia BMC infectious diseases 2013 Johansson

4 QuantiFERON-CMV Measures CMV specific CD8 T cell responses In tube interferon-gamma release technique TGA approved for assessing risk of CMV reactivation post transplant Measure of a patients anti-cmv immunity Negative test is associated with development of CMV disease Positive test is associated with protection Indeterminate due to inadequate mitogen response

5 Verification study 30 healthy control samples from blood donors at the Australian Red Cross. Of the 30 consecutive samples collected 19 patients had previous negative CMV IgG 11 were CMV IgG positive. All samples were tested Duplicate to analyse intra-assay variability Subsequent day to asses for inter-assay variability.

6 C M V -N il o n Ig G - C M V -n il o n Ig G + 90% concordance with serostatus Sensitivity of 81.82%. 2 of our CMV IgG positive samples were CMV QuantiFERON negative C M V r e s u lts o n Ig G p o s itiv e S a m p le n u m b e r Specificity of 94.74% Of the CMV IgG negative group 1 sample was found to be CMV QuantiFERON positive C M V r e s u lts Ig G n e g a tiv e S a m p le n u m b e r

7 Assay Precision Minimal intra-assay variability Correlation coefficient Average intra-assay CV 1.25% Run 1 duplicate 1 vs 2 R² = Minimal inter-assay variability Correlation coefficient first duplicate second duplicate Average inter-assay CV 0.24%

8 Evaluation of the QuantiFERON CMV assay in the prediction of late CMV reactivation and antiviral treatment following solid organ and allogenic stem cell transplantation Recruitment of solid organ transplant patients and HSCT patients from SCGH and FSH CMV QuantiFERON performed a 2 time points At cessation of prophylaxis and 2 months post Retrospectively correlated with CMV viraemia, disease and need for antiviral therapy Primary aim: assess correlation of QuantiFERON CMV with CMV viral loads, disease and anti-viral therapy Secondary aims: assess rates of CMV reactivation, disease and risk factors

9 Preliminary Results HSCT (n=36) CMV serology: D+R+ 47% D+R- 22% D- R+17% D- R- 11% CMV QuantiFERON Positive 44% Negative 35% Indet 18% SOT (n=57 ) Renal 46%, Cardiac 21%, Lung 17%, Liver 16% D+R+ 42% D-R+32% D+R- 21% D-R- 5% Positive 44% Negative 47% Indet 7% CMV reactivation - CMV reactivation <10^3 50% 39% 71% 81% CMV disease 6% 4%

10 HSCT CMV reactivation CMV reactivation >10^3 Average max CMV viral load Valganciclovir treatment Positive QuantiFERON (n=15) Negative QuantiFERON (n=12) 79% 33% 33% 9% 50% 100% Indeterminate QuantiFERON (n=6) 240 copies/ml 3151 copies/ml copies/ml 45% 75% 100% Disease 0% 8% 17%

11 SOT CMV reactivation Reactivation >10^3 Positive QuantiFERON (n=27) Negative QuantiFERON (n=26) 67% 42% 50% 6% 27% 0% Indeterminate QuantiFERON (n=4) Average max CMV viral load Valganciclovir treatment 172 copies/ml 4172 copies/ml 33% 45% 100% Disease 0% 18% 0% 252 copies/ml

12 Max CMV viral load vs QuantiFERON result Positive Negative Indeterminate

13 Risk factors reactivation SOT No CMV reactivation CMV reactivation Prednisolone dose 9.5mg 8.6mg Lymphocyte count 1.48x10^ x10^9 Rejection episodes 8% 39%

14 Risk factors for reactivation: HSCT No reactivation CMV reactivation Prednisolone dose Lymphocyte count 13.5mg 14mg 1.4 x10^9 1.6x10^9 T cell depletion 10% 12% Myeloablative therapy 60% 72% Any GVHD 57% 53%

15 Conclusions QFN-CMV assay performs well in predicting CMV humoral immunity in healthy subjects Late onset CMV viremia is common post transplant Majority low level, CMV disease uncommon Risk factors may include rejection episodes and myeloablative therapy Positive QFN-CMV results are associated with: Lower level viremia Higher spontaneous clearance of viremia Protection from CMV disease Support the utility of QFN-CMV assay as a monitoring tool post transplant

16 Acknowledgements Qiagen Prof Mina John, Dept of Immunology and IIID, Murdoch University Drs Peter Boan, Chris Heath and James Flexman, Dept of Microbiology, FSH and RPH Transplant physicians FSH and SCGH Fiona Stanley Immunology Laboratory George Guelfi, RPH IT Ian James, IIID Murdoch University