Monit itorin ing of of CMV MV infect ctions in tran ansplan lant recipients base sed on C CMV MV specif ific ic cell ll-mediat iated immunity (CM CMI) Dr. Veronica D Di Cristanziano Institute of Virology, University of Cologne
Cytomegalovirus (CMV) • CMV is a ubiquitous β -herpes virus, which infects about 50-90% of the adult population worldwide • CMV is never cleared after primary infection, but persists for the lifetime of the host, establishing a latent infection characterized by limited viral gene expression • Endothelial cells and cells of myeloid lineage (CD34+ hematopoietic progenitors, CD33+ granulocyte-macrophage progenitors and monocyte-derived macrophages) are considered critical sites of CMV persistence and latency • Human immune system cannot eliminate CMV but it is capable of controlling CMV replication • CMV is generally asymptomatic within the normal individual but can cause severe disease in immunocompromised patients (pneumonia, hepatitis, colitis, retinitis, encephalitis) • Transplant recipients (allo-HSCT, SOT)
Pre-transplant CMV assessment • Seropositivity (positive CMV IgG) is used as biomarker for latent CMV infection CMV-specific Ab of donor and recipient is the key diagnostic assay pre-Tx to stratify • the risk of CMV replication and disease post-TX Post-transplant CMV assessment • Viral load monitoring (quantitative real-time PCR) • Frequency, duration, treatment threshold as well as material (plasma, WB) and unite of measure (cop/ml, IU/ml, cop/µg DNA) vary widely between transplant centers
Strategies for prevention of CMV infection/disease in transplant recipients Preemptive therapy: It consists of initiating anti-CMV drugs once CMV is detected at a certain • threshold in whole blood or plasma regardless of clinical symptoms • The most common practice for prevention of CMV infection after allo-HSCT in most cancer centers • A specific threshold for therapy initiation is not well defined • Considering the toxic effects of the available antiviral agents, this strategy could be detrimental for patients at low risk for CMV disease Prophylactic approach: • Administration of anti-CMV agents for 3-6 months post-transplantation • Largely used in case of SOT but unpopular in case of allo-HSCT • Letermovir (LMV) was approved for CMV prophylaxis after allo-HSCT (no evidence of myelotoxicity or nephrotoxicity • Risk of CMV reactivation at the end of prophylaxis (late-onset CMV infection)
CMV after allo-HSCT • CMV is the most common opportunistic viral infection in allo-HSCT recipients • CMV seropositive patients are considered to be at high risk for CMV reactivation • D − /R + > D + /R + > D + /R − > D − /R − • Around 5% of CMV seropositive allo-HSCT recipients develops CMV end-organ disease • CMV infections are associated with graft failure, graft-versus-host disease (GVHD), and secondary bacterial and fungal infections
CMV after kidney transplantation • Highest risk of CMV infection in case of D+/R- • Late-onset disease (CMV viraemia occurring following cessation of prophylaxis) • Allograft rejection and increased mortality
Strategies for prevention of CMV infection/disease in transplant recipients Preemptive therapy: It consists of initiating anti-CMV drugs once CMV is detected at a certain threshold in • whole blood or plasma regardless of clinical symptoms The most common practice for prevention of CMV infection after allo-HSCT in most • cancer centers A specific threshold for therapy initiation is not well defined • • Considering the toxic effects of the available antiviral agents, this strategy could be detrimental for patients at low risk for CMV disease How can we stratify the risk to develop CMV disease? • Prophylactic approach: • Administration of anti-CMV agents for 3-6 months post-transplantation • Largely used in case of SOT but unpopular in case of allo-HSCT Letermovir (LMV) was approved for CMV prophylaxis after allo-HSCT (no evidence of • myelotoxicity or nephrotoxicity • Risk of CMV reactivation at the end of prophylaxis (late-onset CMV infection) • How can we stratify the risk to develop CMV disease?
Consensus-Guideline 2018 “Immune monitoring of CMV-specific T-cell responses can predict individuals at increased risk of CMV disease posttransplant and may be useful in guiding prophylaxis and preemptive therapies.“ The Third International Consensus Guidelines on the Management of Cytomegalovirus in Solid-organ Transplantation, Transplantation 2018
CMV cellular mediated immunity (CMV-CMI) • CMV-CMI is considered the primary defense mechanism to control CMV replication • Both CD4+ and CD8+ T cells are involved in the defense against CMV infection with production of IFN- ɣ • Measurement of CMV specific T cell activity may reflect patients ´ ability to control CMV and predict the risk for post- transplant viral replication • Measurement of IFN- ɣ release might be an useful biomarker for CMV infection
CMV enzyme-linked immunosorbent spot (ELISPOT) assay 1. Peripheral blood mononuclear cells (PBMCs) are isolated from whole blood. The cells are washed, counted and normalized to create a standard cell suspension. 2. A standard number of cells are added into specially designed plates and stimulated with CMV-specific antigens pp65 and IE-1. Cells responding to these antigens release the cytokine IFN- ɣ 3. IFN- ɣ antibodies are used to directly capture IFN- ɣ as it is released by the cells. A secondary labelled antibody is added and binds to the captured IFN- ɣ 4. A detection reagent is added and reacts with the secondary labelled antibody. This reaction produces spots, which are footprints of where the IFN- ɣ was released. Spots are then enumerated.
Many recent publications showed that the assessment of CMV-specific immunity (ELISPOT) is able to predict protection from CMV infection in transplant recipients
Ongoing studies • VIRENO study: viro-immunological monitoring based on anti-BKPyV antibodies detection, CMV IGRA, and TTV-DNA before and 3 weeks and 6 months after KTx • Viro-immunological monitoring after cessation LMV prophylaxis in allo-HSCT recipients (IGRAs, TTV-DNA)
T-cell response in a healthy CMV seropositive individual IE1 pp65 CTRL+
Patient 1 CMV reactivation in D+/R+ Rituximab Immunadsorptionen
Patient 1 CMV reactivation in D+/R+ Rituximab Immunadsorptionen
CMV Elispot monitoring in an allo-HSCT D-/R+ recipient after cessation of LMV prophylaxis Patient 2 IE1 44 74 108 pp65 395 979 1056 CTRL+ 493 1212 1237 +200 day +280 day +220 day
CMV Elispot monitoring in an allo-HSCT D-/R+ recipient after cessation of LMV prophylaxis Patient 3 IE1 3 1 2 6 47 pp65 20 23 116 147 230 CRTL+ 244 348 877 736 1009 +200 +210 +240 +270 +330 1250 870
Thank you, dankeschön, grazie Klinik für Viszeral- und Transplantationschirurgie Institut für Virologie Klinik für Nephrologie • Prof. Dirk Stippel • Dr. Rolf Kaiser • Dr. Roman Müller • Dr. Roger Wahba • Dr. Eva Heger • Prof. Christine Kurschat • Dr. Georg Dieplinger • Dr. Elena Knops • Dr. Martin Kann • Dr. Gertrud Steger • Joanna Wessel • Prof. Florian Klein Uniklinik Düsseldorf Dr. Ortwin Adams Dr. Nadine Lübke Prof. Guido Kobbe
Don´t forget it !
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