Cytomegalovirus (CMV) is a common infection in liver transplant recipients that can cause direct tissue damage or indirect effects like rejection. It is transmitted from donor to recipient in 50-97% of transplant cases and reactivates due to immunosuppression. Prevention methods include preemptive antiviral therapy for high-risk patients based on viral load screening or prophylaxis for 3-6 months. Valganciclovir is commonly used but toxicity and late-onset infection are risks, especially in donor-positive/recipient-negative cases. Treatment involves reducing immunosuppression and antivirals like intravenous ganciclovir or valganciclovir for 2-6 months. CMV

1. Cytomegalovirus (CMV), the
hidden enemy in liver
transplantation
Ayman Alsebaey, MD.
Lecturer of hepatology,
National liver Institute,
National Liver Institute Congress
Conrad, April 2015

2. The past, the
present, and
the future‫‏‬‫‏‬

3.  Cytomegalovirus (CMV) is a double stranded DNA virus.
 CMV infects 50−97% of the human population. It remains lifelong latent in
the hematopoietic cells.
MODE OF INFECTION IN LT STATUS
 Primary CMV infection (D+/R−):
 A sero−negative recipient receives organ from sero−positive donor.
 Secondary CMV infection (Reactivation D±/R+):
 The recipient is sero−positive and immunosuppression induces
reactivation of latent CMV infection.
 Superinfection (D+/R+):
 Both the donor and the recipient are sero−positive. Here there is
reactivation of the donor CMV.
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4. INCIDENCE OF CMV INFECTION IN LT RECIPIENTS
1. If no prevention used post LT, 18−30% of the recipients will develop
CMV disease especially in the 1st 3 months.
a. D−/R−: 1−2%.
b. D+/R−: up to 65%.
c. D±/R+: up to 20%.
2. With prevention by 3 month of valganciclovir or oral ganciclovir
prophylaxis:
a. D+/R−: 10−30%.
b. D±/R+: <10%.
3. Late CMV:
a. is the reactivation of CMV following 3 months prophylaxis so
prophylaxis should be prolonged to 6 months.
b. D+/R−: 15%.
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5. RISK FACTORS FOR CMV INFECTION IN LT RECIPIENTS:
 Donor/Recipient status:
a. Risk of infection in CMV D+/R− > CMV D±/R+.
 Immunosuppressive dose and prolonged use:
a. Lymphocyte-depleting drugs (alemtuzumab >anti−thymocyte globulin
>basiliximab).
b. High doses mycophenolate mofetil.
c. Sirolimus and everolimus decrease CMV replication.
 Defects in innate immunity and cytokine defects:
a. Polymorphisms in mannose-binding lectin and toll-like receptor 2 genes.
 Allograft rejection (bi-directional):
a. Rejection   TNF   CMV re−activation  Pulse steroids.
b. Rejection increases CMV replication.
 Co-infections with HHV-6 and HHV-7 : as being immunomodulatory.
 Cold ischemia time, bacterial, fungal infections, sepsis, the amount of blood
loss and fulminant hepatic failure.
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6. Risk factors for CMV infection in LT recipients
Traditional Risk Factors Recently Described Risk Factors
 CMV D+/R–
 Lack of CMV−specific CD4+ T cells
 Lack of CMV−specific CD8+ T cells
 Allograft rejection
 High viral replication
 Type of organ transplant
 Mycophenolate mofetil
 Muromonab−CD3
 Antithymocyte globulin
 Alemtuzumab
 HHV−6
 HHV−7
 Renal insufficiency
 Toll−like receptor 2 polymorphism
 Toll−like receptor 4 polymorphism
 Mannose−binding lectin deficiency
 Chemokine and cytokine defects
(interleukin 10, monocyte chemotactic
protein 1, C−C chemokine receptor
type 5)
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7. CLINICAL MANIFESTATIONS OF CMV DISEASE
DIRECT EFFECTS INDIRECT EFFECTS
 Asymptomatic:
 Only positive PCR
 CMV syndrome (60%):
 Fever, flu like
 Myelosuppression with leukopenia and
neutropenia
 Tissue-invasive CMV disease:
 GIT (70%); esophagitis, gastritis,
enteritis, colitis.
 Hepatitis.
 Pneumonitis.
 CNS disease.
 Retinitis.
 Intrauterine transmission.
 Mortality
 Acute allograft rejection
 Chronic allograft rejection
 Vanishing bile duct syndrome
 Chronic ductopenic rejection
 HAT
 Hepatitis C virus recurrence
 Allograft hepatitis, fibrosis
 Allograft failure
 Opportunistic and other infections
 Fungal superinfection
 Nocardiosis
 Bacterial superinfection
 Epstein−Barr virus and PTLD
 HHV−6 and HHV−7 infections
 Vascular thrombosis
 New onset diabetes mellitus
 Mortality IMMUNOMODULATORY &
IMMUNE EXHAUSTION
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8. DIAGNOSIS
1. CMV NAT:
a. Rapid and more accurate (CMV DNA >RNA).
b. Quantitative, useful in initiation and follow up of treatment.
c. Prognostic:
i. Pre−treatment CMV DNA <18,200 IU/ml 1.5 fold higher
chance for CMV disease resolution.
ii. CMV suppression to <137 IU/mL is predictive of clinical response
to antiviral treatment.
2. pp65 antigenemia assay:
a. is secreted by CMV-infected peripheral blood leukocytes.
b. Comparable to NAT
c. Semi−quantitative, processed within 6−8 h of blood collection,
d. but requires a large sample volume, subjective interpretation of results
and falsely negative in patients with severe leukopenia.
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9. DIAGNOSIS:
1. Histopathology:
a. Gold standard for the
diagnosis of tissue-invasive
CMV disease though
invasive.
b. Cytomegalic cells with
positive
immunohistochemical testing.
c. Nowadays indicated to
exclude rejection and
diagnose
compartmentalization.
2. Non useful tests:
a. Serology (Ig M and Ig G).
b. Viral cultures.
COMPARTMENTALIZED
CMV DISEASE:
1. Positive tissue CMV infection
with negative blood PCR.
2. So follow up of PCR may
escape viral detection as
preemptive therapy.
3. Commonly seen in the GIT
and retina.
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10. Methods Principle Sample and Equipment Turnaround Time Clinical Usefulness Advantages Disadvantages
Serology Antibody detection
(IgG, IgM)
Serology facility 6 h IgG indicates previous
infection
IgM implies acute or
recent infection
Screening of donors and
recipients before
transplantation
Screening transplant
recipients after
transplantation to detect
seroconversion
Delayed antibody
production in transplant
recipients (false-negative
results)
False-positive IgM
screening results
Virus culture
Tube culture Viral replication Recovery of PMN within few hours;
cell culture facility; light microscopy
2–4 wk Detection of
cytopathic effects
High specificity for
infection and disease
Phenotypic susceptibility
testing
Prolonged processing time
Low sensitivity
Rapid loss of CMV viability
ex vivo (false-negative
results)
Shell vial assay Viral replication Recovery of PMN within few hours;
cell culture facility;
immunofluorescence detection
16–48 h Infectious foci
detected by
monoclonal antibody
directed to immediate
early antigen (72 kDa)
of CMV
High specificity for CMV
infection and disease
More sensitive and rapid
than tube cultures
Relatively low sensitivity
compared with molecular
methods
Antigenemia pp65 Antigen Recovery of PMN within 4–6 h;
Cytospin; light microscopy or
immunofluorescence
6–24 h Number of CMV-
infected cells per total
(eg, 2 × 105) cells
evaluated; early
detection of CMV
replication
Rapid diagnosis of CMV
Guide for initiation of
preemptive therapy
Guide for treatment
responses
Subjective interpretation of
results
Requires rapid processing
Nucleic acid
detection
DNA or RNA Plasma, whole blood, leukocytes,
other body fluids
4–24 h Reported as CMV
copies per milliliter of
sample (should now
be standardized to
IU/ml of sample)
Detection of CMV
infection; monitor CMV
DNA decline;
surrogate marker for
antiviral drug
resistance
Highly sensitive
Correlation with clinical
disease severity
Guides preemptive
therapy
Rapid diagnosis of CMV
infection and disease
Monitor therapeutic
response
Modest positive predictive
value for CMV disease
Needs standardization
among various assays
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11. Prevention of
CMV disease
post LT
Preemptive
therapy
Antiviral
prophylaxis
Hybrid
approach
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12. PREEMPTIVE THERAPY
a. Regular weekly screening for +ve CMV PCR or +ve pp56 antigenemia till
week 12 especially after antilymphocyte antibody therapy.
b. Aim:
a. is to prevent progression to symptomatic clinical disease.
b. Once CMV is detected, start the treatment.
c. Less cost:
a. Offset by the cost of laboratory testing, increased logistic
coordination.
d. Less likely associated with late onset CMV disease.
e. Not effective in D+/R− liver recipients so antiviral prophylaxis is the rule.
f. Should be used only with D±/R+ liver recipients
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13. ANTIVIRAL PROPHYLAXIS
a. Administration of antiviral drugs such as valganciclovir to all patients at risk
of CMV disease after liver transplantation.
a. Used drugs: oral ganciclovir, I.V ganciclovir, valganciclovir.
b. Advantages:
a. Prevention of direct and indirect CMV effects.
b. Decreased incidence of herpes, bacterial, protozon infections, rejection
and mortality
c. Should be used to D+/R− liver recipients.
c. Disadvantages:
a.  antiviral drug cost, drug-related toxicity and resistance.
b.  incidence of late-onset CMV disease (esp. D+/R– LT recipients.
d. Valganciclovir vs. ganciclovir prophylaxis:
a. Oral ganciclovir is poorly absorbed so IV should be used.
b. Oral 950 mg valganciclovir = 5mg/kg IV ganciclovir.
c. New studies 450 mg = 950 mg valganciclovir.
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6m 12m
Valganciclovir Oral Ganciclovir
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CMV disease in liver recipients
Valganciclovir Oral Ganciclovir
A randomized trial of 372 CMV D+/R– kidney, liver, pancreas,
and heart recipients

FDA has cautioned against valganciclovir prophylaxis in liver recipients,
although many experts still recommend its use in liver recipients
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15. a. Maribavir prophylaxis: is investigation drug that is less effective than oral
ganciclovir so is on hold.
b. CMV immunoglobulin: Its role when combined with anti CMV drugs is
debate.
HYBRID APPROACH
 Prophylaxis is started for 3 month then preemptive strategy is the role.
LATE−ONSET CMV DISEASE
 In high−risk CMV D+/R− individuals, the use of antiviral prophylaxis for
100 d has only delayed the onset of CMV disease to 3−6 month after liver
transplantation.
 associated with allograft failure and mortality
 Prevention:
 Clinical follow-up with early treatment of CMV disease when
symptoms occur;
 Virologic surveillance after completion of antiviral prophylaxis
 Prolonging antiviral prophylaxis.
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16. 16.1
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200 day Val 100 day Val
CMV disease
A randomized trial compared 200 versus 100 days of
valganciclovir prophylaxis in 318 CMV D+/R– kidney recipients
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17. Antiviral Prophylaxis Preemptive Therapy
Efficacy • Highly efficacious for CMV
disease prevention
• Risk of late-onset CMV disease
• Prevents CMV disease but not
CMV infection
Logistics of use • Needs monitoring of potential
adverse effects such as
leukopenia
• Difficult to coordinate weekly
viral load testing and results
follow-up
• Viral load thresholds not
standardized
Late-onset CMV
disease
• Common among CMV D+/R–
transplant recipients
• Less common
Cost • Higher drug costs • Higher laboratory costs
Toxicity • Greater drug toxicity
(leukopenia and bone marrow
suppression)
• Less drug toxicity (shorter
courses of antiviral treatment)
Indirect effects (graft
loss, mortality, and
opportunistic infections)
• Reduction in indirect effects • May not reduce indirect effects
(limited data available)
Drug resistance • Yes (but still uncommon) • Yes (but still uncommon)
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18. TREATMENT
1. Used drugs:
1. Oral ganciclovir should not be used.
2. Oral valganciclovir and IV ganciclovir.
3. Less used drugs:
a. Cidofovir and foscarnet are high active, highly nephrotoxic.
b. IV immunoglobulin maybe adjuvant therapy.
2. Decrease to immunosuppressive level:
1. to allow the immune system to act against CMV.
2. Shift to mTor inhibitors.
3. Mild to moderate disease: oral valganciclovir and IV ganciclovir are
comparable.
4. Severe disease, high viral load, GIT invasion:
1. use only IV ganciclovir,
2. after improvement use oral valganciclovir.
5. Duration of treatment:
a. 14-21 day followed by 4-12 week prophylaxis to prevent relapse (35%).
6. End point of treatment: 2 negative PCRs one week apart.
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19. Antiviral drugs for CMV prevention and treatment
Drug
Preemptive Therapy and
Treatment of CMV Disease
Antiviral Prophylaxis Comments on Use and Toxicity
Valganciclovir • 900 mg by mouth twice daily • 900 mg by mouth once
daily
• Ease of administration
Leukopenia
Oral ganciclovir • Not recommended • 1 g by mouth 3 times
daily
• Low oral bioavailability
High pill burden
• Leukopenia
• Risk of resistance
IV ganciclovir • 5 mg/kg IV every 12 h • 5 mg/kg IV once daily • IV access
Leukopenia
Valacyclovir • Not recommended • 2 g by mouth 4 times
daily
• Kidney transplant recipients only
• Not recommended for heart, liver,
pancreas, lung, intestinal, and
composite tissue transplant recipients
High pill burden
• Neurologic adverse effects
Foscarnet • 60 mg/kg IV every 8 h (or 90
mg/kg every 12 h)
• Not recommended for
preemptive therapy
• Not recommended • Second-line agent for treatment
• Highly nephrotoxic
• Treatment of UL97-mutant
ganciclovir-resistant CMV
Cidofovir • 5 mg/kg once weekly × 2 then
every 2 wk thereafter
• Not recommended for
preemptive therapy
• Not recommended • Third-line agent
• Highly nephrotoxic
• Treatment of UL97-mutant
ganciclovir-resistant CMV
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20. 1. It is a common with prolonged anti CMV drugs use e.g. antiviral
prophylaxis or preemptive therapy and D+/R– recipients.
2. It is detected when the viral load did not decrease from the baseline or
even breakthrough.
3. Incidence: is low (0.26%) but common with D+/R– recipients, over
immunosuppression and recurrent rejection.
4. Phenotypes:
a. Ganciclovir resistance is more common.
b. Isolated or cross resistance to cidofovir or foscarnet is less common.
5. Genetics:
a. UL97: phosphorylates ganciclovir to ganciclovir triphosphate. So
mutations cause only ganciclovir resistance.
b. UL54: activates ganciclovir triphosphate to inhibit CMV DNA
polymerase. So mutations cause ganciclovir resistance and
foscarnet and cidofovir resistance.
c. Combined mutations.
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DRUG-RESISTANT CMV INFECTION AND DISEASE

21. TREATMENT OF DRUG-RESISTANT CMV INFECTION
 Decrease immunosuppression ±shift to mTOR inhibitors.
 Genetic mapping of UL54 and UL97 genes.
 UL54 mutations:
• Vaccines.
• intravenous immunoglobulin.
• Letermovir (AIC246): UL56 terminase inhibitor.
• Maribavir
• Brincidofovir (CMX001): prodrug of cidofovir
• Leflunomide: drug for rheumatoid arthritis inhibiting viral kinases.
• Artesunate: anti-malarial
• CMV-specific T cells.
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Thanks a lot