This document provides information on cytomegalovirus (CMV), a herpes virus. Some key points: - CMV was first isolated in 1956 from infants and causes lifelong latent infection. It is a major cause of disease in transplant recipients. - CMV infection is generally asymptomatic in healthy individuals but can cause disease in the immunocompromised via direct tissue damage or indirect immune effects. - Diagnosis involves detecting viral DNA, antigens, or culture. Treatment includes antivirals like ganciclovir or valganciclovir. - Prevention strategies for transplant recipients include preemptive therapy based on viral monitoring or prophylaxis for high risk groups to reduce disease and

1. CYTOMEGALOVIRUS

2. HISTORY
 First isolated in 1956 from 2 dying infants
from salivary gland and kidneys with
demonstration of inclusion bodies
 “Salivary Gland Virus”
 1960 Wellar et al proposed name
‘cytomegalovirus’
 CMV first isolated from renal transplant
patient in 1965

3. CMV (CYTOMEGALOVIRUS)
 Human herpes virus type 5 (HHV-5)
 The largest in Herpesvirus
Immunobiology of human cytomegalovirus
Clin Microbiol Rev. 2009 Jan;22(1):76-98
http://www.iayork.com
CMV Structure
Double-stranded DNA core
Icosahedral nucleocapsid
Tegument
(proteinaceous matrix)
Lipid bilayer envelope
contains Glycoproteins

5. EPIDEMIOLOGY
 Seroprevalence of CMV in the human population:
30~90% in developed countries and may be higher in
developing countries, increasing with age.
 Transmitted via:
 Saliva
 Sexual contact
 Placental transfer
 Breastfeeding
 Blood transfusion
 Solid-organ transplantation
 Hematopoietic stem cell transplantation

6. IMMUNE CONTROL
 Generally, CMV infection is held
in check by the host’s immune response.
 Primary CMV infection in an immunocompetent host is
normally asymptomatic.
→ CMV disease is generally restricted to the
immunocompromised host.
 CMV has the ability of lifelong persistent, latent infection,
and can reactivate under certain conditions.
→ In transplant recipients,
infection with CMV from the donor organ
or the reactivation of CMV in the recipient
can lead to disease development.

7. IMPORTANCE OF CMV INFECTION
 In the absence of any form of antiviral prophylaxis,
CMV disease occurs in 20–30% of transplant recipients,
with a vast majority of the episodes
developing within 90 days post-transplant.
 The single most important infectious complication
after solid organ transplant(SOT).
 A major complication
of hematopoietic stem cell transplantation(HSCT).
⇒ CMV is a major cause of morbidity
in transplant recipients.

8. CMV - PATHOGENESIS
 WBCs and CD 13 + are reservoir cells
 Detected in most tissues of body and remains latent
 Enter host cell by fusion or phagocytosis
 Viral particles are made and assembled in nucleus , attain
envelope by budding through inner nuclear membrane
 Replication produces immediate early (IE), early and late
antigens
 IE (nucleus) : direct production of viral and cellular genes
 Early (cytoplasm) : directs viral DNA synthesis
 Late ( Nucleus + Cytoplasm) : directs production of
structural nucleocapsid proteins
 Antivirals interupt DNA synthesis

9. ALSO …..
 IE gene upregulates transcription and
expression of IL - 2 and IL- 2 receptor
 IE gene prevents inhibitory effect of
cyclosporine on IL – 2 gene transcription
 IE and early antigens also upregulate
adhesion molecules such as ICAM –1 and
LFA – 3, further increased by antiviral agents
 CMV has ability to down regulate MHC class
1 molecules

10. CMV AND SOLID ORGAN TRANSPLANTATION
• CMV is still among the most important infectious
complications after transplant
• In the absence of prophylaxis, CMV reactivation can occur
in over 75% of solid organ transplant recipients depending
on other risk factors(1)
• Once CMV infection is established, then its replication is
highly dynamic with rapid increases in viral load
 CMV infection may lead to tissue invasive disease
10
1. Fishman JA, Rubin RH. Infection in organ-transplant recipients. N Engl J Med.

11. CMV INFECTION: RISK CATEGORIES IN
SOLID ORGAN TRANSPLANT RECIPIENTS
Risk Category
Donor (D) or Recipient (R)
Seropositivity (+/-)
High D+/R-
Intermediate* D+/R+, D-/R+
Low D-/R-
11
* D+/R+ generally at higher risk than D-/R+
Fishman JA, Emery V, Freeman R, et al. Cytomegalovirus in transplantation –
challenging the status quo. Clinical Transplantation. 2007;21:149-158.

12. OTHER RISK FACTORS
 Type of organ
– Lung/small intestines > pancreas, heart > liver, kidney
– Due to transplanted load; immune response in the allograft;
level of immunosuppression
 Intensity of immunosuppression
– Antilymphocyte products (e.g., thymoglobulin)
– Dose, duration, and overall intensity of drugs
– Newer agents – alemtuzumab, others?
12

13. CMV PATHOGENESIS
• Viral factors
– replication dynamics
– immune evasion
– viral heterogeneity
– viral co-infections
• Host factors
– CD4+, CD8+ T-cell
– NK cell, B-cell
– exogenous
immunosuppression
– D/R immune status
13

14. INFLAMMATION
(CYTOKINES, NF-B)
LATENT CMV INFECTION
ANTILYMPHOCYTE
ANTIBODIES
OTHER
HERPES VIRUSES
SEPSIS/
SURGERYREJECTION
14

15. CMV INFECTION
Latent CMV infection
Active CMV infection
(viral replication)
Direct
effects
Indirect
effects
15

16. DIRECT EFFECTS OF CMV INFECTION
CMV Viral Syndrome
• Fever, malaise, myalgias
• Leukopenia, thrombocytopenia,
and other laboratory
abnormalities
Tissue Invasive Disease
• Hepatitis
• Pneumonitis
• Colitis
• Carditis
• Nephritis
• Pancreatitis
• Retinitis
Direct Effects
16

17. INDIRECT EFFECTS OF CMV INFECTION
Altered host immune response
• Graft rejection; graft dysfunction
• Opportunistic infections: Bacterial
fungal superinfection
• Decreased graft and patient survival
• Herpesvirus interactions: EBV/PTLD
Indirect Effects
17

18. Infection in Solid-Organ Transplant Recipients
N Engl J Med 2007;357:2601-14
CLINICAL FEATURES
Cellular effects: MHC, cytokine expression
“indirect effects”
CMV disease
“direct effects”
CMV
Syndrome
(fever,
myalgia,,)
End-organ
Disease
(pn, colitis,
retinitis,,,)
Allograft
injury
Allograft
rejection
EBV-
associated
PTLD
Opportu-
nistic
infections
Atherosclerosis, BO, etc
Active CMV infection
(viremia and tissue infection)
Latent
CMV infection

19. Management of CMV infection and Disease in Transplant Patients
Herpes. 2004 Dec;11(3):77-86
www.mdconsult.com

20. CMV HEPATITIS
20

21. Chorioretinitis after liver transplantation
Transpl Infect Dis 2008:10:27-43
The right eye showed diffuse fundus blurring with visual loss,
The left eye presented with cotton-wool spots and hemorrhage.
CLINICAL FEATURES - RETINITIS

22. Cytomegalovirus Pneumonia After Stem Cell Transplantation
AJR 2006; 187:W636–W643
Small ill-defined centrilobular opacities
Patchy GGO and septal edema
CLINICAL FEATURES - PNEUMONIA

23. CLINICAL FEATURES - COLITIS

24. CMV AND KIDNEY
 Glomerular Disease
 Tubulointerstial Disease
 Kidney transplant rejection with or without
glomerular involvement

25. CMV AND KIDNEY
 Nephrotic syndrome due to MN especially in infants and
children with primary CMV syndrome
 Necrotising and proliferative glomerulonephritis
 Adult Ig A Nephropathy – association not fully understood
 HSP
 Type II Cryoglobulinemia
 Type I MPGN
 Collapsing FSGS
 Thrombotic Microangiopathy
 Transplant Glomerulopathy
 Tubular inclusions + interstial infiltrate have been seen
with bone marrow transplant patients

26. CMV - DIAGNOSIS
A. seroconversion with the appearance of anti-CMV IgM
antibodies
B. a fourfold increase in preexisting anti-CMV IgG titers
C. detection of CMV antigens in infected cells
D. detection of CMV-DNAemia by molecular techniques
E. isolation of the virus by culture of the throat, buffy
coat, or urine.

27. CMV DIAGNOSIS
 Diagnosis
CMV disease: acute symptomatic + evidence
of CMV infection
1.Quantitative CMV DNA by PCR
diagnosis and monitor response
2.Qualitative CMV DNA detection by PCR
extremely sensitive, can’t diff active or
latent
3.CMV pp65 antigen: in peripheral lymphocyte
semiquantitative fluorescent assay more rapid >
C/S

28. CMV DIAGNOSIS
4.Tissue culture: delay diagnosis
5.Serum CMV IgM IgG Ab: good for screening
before KT but not sensitive for diagnosis
6 Histopathology: delay diagnosis and inadequate
specimen collection

29. Characterized by intra-nuclear inclusion with enlargement of both
cell & nucleus. Cytoplasmic inclusions are also seen in the infected
cells.

30. There are foci of concentrated inflammatory
infiltrate in renal parenchyma

31. Enlarged CMV-infected renal tubular epithelial cells with
prominent intranuclear inclusion surrounded by a clear halo
(bull-eye appearance).

32. CMV-infected renal tubular epithelial cell with typical bull-eye
appearance. Note the rather enlarged CMV-infected cell as compared to
adjacent normal renal tubular epithelial cells.

33. Time of Presentation of Common Viral Illnesses Post-Transplant
Viral Infection after Renal Transplantation Clin J Am Soc Nephrol 3: S76–S86, 2008

34. Improving Outcomes for Solid-Organ Transplant Recipients At Risk from
Cytomegalovirus Infection: Late-Onset Disease and Indirect Consequences
Clinical Infectious Diseases 2008; 46:732–40
Five-year follow-up data for patients with persistent cytomegalovirus (CMV) infection of
the graft, showing graft survival in patients with persistent CMV infection, compared with
patients with nonpersistent or no CMV infection in the graft.
CLINICAL FEATURES – GRAFT SURVIVAL
CMV(-)
CMV(+)

35. CMV TREATMENT
 In immunocompetent hosts the disease may
be asymptomatic and no treatment may be
required
 Tapering of immunosuppresants may be
required
 mononucleosis-like syndrome may resolve
without the administration of antiviral drugs
 Invasive disease need anti-viral drugs

36. IMMUNOSUPPRESIVE THERAPY
 azathioprine or mycophenolate mofetil should be
given in reduced dosage or discontinued.
 Reduced immunotherapy is necessary when there is
evidence of tissue invasive disease and organ
involvement (including chorioretinitis).
 cyclosporine or tacrolimus should be discontinued in
this setting remains controversial.
 We usually do not discontinue cyclosporine or
tacrolimus unless there is evidence of life-
threatening infection
 Corticosteroids are generally continued to prevent
possible adrenal insufficiency.

37. ANTI-CMV THERAPY
 Ganciclovir: (Cytovene® and Cymevene®) is a synthetic analogue of
2-deoxyguanosine, that competitively inhibits the incorporation of
dGTP by viral DNA polymerase–intravenous or oral
 Valganciclovir: (Valcyte®) a prodrug form of ganciclovir with
improved oral bioavailability
 Foscarnet: (Foscavir) is an inhibitor CMV DNA polymerase (UL54)
‒ Useful for ganciclovir resistant CMV
‒ Major limitation is nephrotoxicity
 Cidofovir: (Vistide) inhibits viral DNA polymerase
‒ May be useful for ganciclovir resistant CMV but not well studied in organ
transplant recipients
 Maribavir: is an investigational agent that prevents viral
encapsidation and nuclear egress
37

38. CMV TREATMENT
• Mild to moderate CMV disease: oral
valganciclovir = i.v. ganciclovir
• Severe CMV disease:
- high CMV viral load > 5 x 105 copies/ml
- severe tissue invasive disease
- fail achieve viral load reduction after D7 of
oral valganciclovir

39.  ganciclovir 5 mg/kg every 12 hours until viremia
suppression (usually 14-21 days)
 Blood for viral load at least q 1 week
 Prior to initial treatment need to be excluded. As an
example, CMV infection may be associated with
Pneumocystis carinii pneumonia,
• if ongoing risk for CMV : long term maintenance
- oral ganciclovir 1 g tid
- valganciclovir 450-900 mg OD

40. CMV PREVENTION
• Pre-emptive
– Guided by laboratory monitoring for evidence of early viral
replication; treatment is started when CMV viral load or
antigenemia reaches a certain threshold
• Universal prophylaxis
– Therapy from the time of transplant to all patients
or a subgroup of patients at risk for CMV disease
40

41. + + + + + __ + + _
0 4 8 12
weeks
Initiate pre-emptive therapy to prevent
CMV disease
CMV disease
TEST
PRE-EMPTIVE THERAPY
__
41

42. PRE-EMPTIVE THERAPY
• Advantages:
– Minimizes drug exposure
– This may potentially decrease toxicity and costs
– Theoretically lower risk of resistance
– Less late-onset disease: may allow development of
cell-mediated immune response
• Disadvantages:
– Logistically more difficult to coordinate
– May be unsuccessful in preventing progression to active disease in
high-risk patients due to rapid doubling time
– May not eliminate the indirect effects of CMV
42

43. MODELING THE DYNAMICS OF CMV REPLICATION
Log10ViralLoad
Time
(days)
Doubling time = ln2/a
y = y0eax
Average DT= 1-2 days
Detection threshold
43Emery V, et al. Lancet. 2000;355(9220):2032-2036.

44. ANTIVIRAL PROPHYLAXIS
• Antiviral therapy from the time of transplant to all
patients or a subgroup of patients (universal or targeted)
• Advantages:
– Proven efficacy
– Decreases indirect effects
– Ease of administration
• Disadvantages:
– Drug toxicity, cost
– Resistance
– Late-onset CMV disease
44

45. 0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
CMV Disease CMV Syndrome CMV Invasive Organ
Disease
RelativeRisk
CMV PROPHYLAXIS
Hodson, et al. Cochrane Database Sys Rev. 2008;2:CD003774.
0.42
0.34
0.41
45

46. EFFECTS OF ANTI-CMV PROPHYLAXIS
ON CONCOMITANT INFECTIONS
46
Hodson EM, et al. Lancet. 2005;365:2105-2115.

47. LATE ONSET CMV DISEASE DEFINITION
• CMV disease occurring > 3 months post transplant
• May be primary infection (D+/R-) or recurrence (R+)
• In epidemiology studies associated with significant
morbidity (including graft dysfunction) and occasional
mortality (indirect effects)(1)
• Incidence 3%-17%; In IMPACT study 37% with 3 months of
prophylaxis in D+/R-
47
Limaye, AP, et al. Transplantation. 2004;78(9):1390-1396.

48. CMV PROPHYLAXIS: LATE-ONSET DISEASE
Prophylaxis period
PatientsWithNoCMVDisease(%)
0
10
20
30
40
50
60
70
80
90
100
Time (days)
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200
364 D+/R- SOT patients
Ganciclovir (oral)
Valganciclovir
Paya, et al. Am J Transplant. 2004;4:611-620.48

49. PRE-EMPTIVE VS. PROPHYLAXIS
 There are very few comparative randomized trials
comparing pre-emptive therapy vs. prophylaxis
 Khoury et al: 98 kidney transplant patients randomized to
pre-emptive therapy (valganciclovir) vs. prophylaxis
(valganciclovir 100 days)
‒ Equally effective in preventing CMV disease
 Kliem et al: randomized 148 renal transplant patients to
pre-emptive therapy (I.V. ganciclovir) vs. prophylaxis
(3 months oral ganciclovir)
‒ Long-term graft survival at 4-years post transplant was
significantly improved in the prophylaxis group
49
Khoury JA, et al. Am J Transplant. 2006;6(9):2134-2143.
Kliem V, et al. Am J Transplant. 2008;8(5):975-983.

50. Prophylaxis Pre-emptive
Evidence of efficacy +++ ++
Indirect effects/mortality ++ +
Other viruses + for some ?
Ease ++ +/-
Late onset disease ++ -
Resistance Low Very Low
PROPHYLAXIS VS. PRE-EMPTIVE THERAPY
50

51. WHAT ABOUT PROLONGING PROPHYLAXIS?
• Potential benefits
– decrease disease
– improve graft outcomes
• Potential pitfalls
– push disease further?
– cost
– toxicity
51

52. THE IMPACT TRIAL
• Kidney recipients, D+/R-, N=316
• 3 months of valganciclovir + 3 months placebo vs.
6 months of valganciclovir
• 900 mg QD dose adjusted
• Incidence of CMV disease at 12 and 24 months
post transplant
52
Humar A, et al. Am J Transplant. 2009;9(suppl2):248. Abstract 201.

53. DESIGN
Valganciclovir 900 mg od*
Valganciclovir 900 mg od* Valganciclovir 900 mg od*
Placebo
100 days 200 daysRandomization 12 months
post transplant
VGCV-100 days:
VGCV-200 days:
* dose adjusted for renal function
Humar A, et al. Am J Transplant. 2009;9(suppl 2):248. Abstract 201.53

54. CONFIRMED CMV DISEASE
36.8 16.1
0
10
20
30
40
50
VGCV-100 days VGCV-200 days
Proportionofpatientswithconfirmed
CMVdiseaseat12months(%) p < 0.0001
* Patients without an assessable month 12 status are not assumed to have the event in this sensitivity
analysis.
Humar A, et al. Am J Transplant. 2009;9(suppl 2):248. Abstract 201.54

55. INCIDENCE OF CONFIRMED CMV DISEASE
0
0.4
0.2
0
0.8
0.6
18060 120 240 360
1.0
300
Event-freeprobability
Study day
Number of patients left
VGCV-100 days 163 161 161 157 151 125 110 104 102 101 95 94 83 4
VGCV-200 days 155 154 152 150 149 147 145 143 136 130 125 122 120 7
VGCV 200 days
VGCV 100 days
Humar A, et al. Am J Transplant. 2009;9(suppl 2):248. Abstract 201.55

56. CMV TREATMENT
• Treat with full dose IV ganciclovir or oral valganciclovir
(VICTOR trial)(1)
• Monitor CMV viral load or antigenemia once weekly while
on therapy
• Generally, continue treatment until undetectable
• May consider a 1-3 month course of secondary
prophylaxis after completion of treatment
561. Ashberg A, et al. Am J Transplant. 2007;7(9):2106-2113.

57. ORAL VS. IV THERAPY OF CMV
VICTOR TRIAL
Maintenance
Day 21 to 49
Follow-up Phase
Month 3 to 12
Induction
Day 0 to 20
Oral
valganciclovir
900 mg BID
Oral
valganciclovir
900 mg QD
No study
medicationCMV Disease
IV ganciclovir
5 mg/kg BID
• Multicenter non-inferiority study
• 42 centers: 25 in Europe, 9 in Latin America, 4 in India, 2 in Canada, 2
in Australia and New Zealand
Asberg, et al. AJT. 2007;7(9):2106-2113.57

58. CMV DRUG RESISTANCE DIAGNOSIS
• Increases of viral load as surrogate marker for resistance
– drug naïve subjects, early during treatment, low-risk setting (R+)
• drug resistance unlikely
• increases most likely due to the underlying
immunosuppression
– after significant exposure (especially low dose), high-risk setting
• more likely
• true viral load increase >0.5 log10 (>3x baseline)
• Testing: direct genotypic testing if resistance is suspected
– UL97 gene: ganciclovir
– UL 54 gene: foscarnet, cidofovir, ganciclovir (high level)
58

59. CMV RESISTANCE: PROPOSED MANAGEMENT ALGORITHM
59
At least 2 weeks of adequate
dose
of ganciclovir with increasing or
unchanged viral load
Reduce immunosuppression.
Send for genotypic resistance
testing
Severe CMV disease Non-severe CMV disease
Switch to or add foscarnet
at full dose
Increase ganciclovir dose up to
10 mg/kg BID or ½ dose
ganciclovir / ½ dose foscarnet
Alter therapy based on
genotypic resistance testing and
clinical response. Adjunctive
unproven therapy may be
required.

60. NEW DRUGS? MARIBAVIR
 Maribavir
– Inhibits CMV UL97: prevents viral encapsidation and nuclear
egress
– Potent in vitro activity against CMV
– Phase 3 halted OLTx, BMT due to failure primary endpoint
60

61. WHAT DOES THE FUTURE HOLD?
• Use of translational research to establish better
predictive tools
– host response: CD8, CD4 responses to specific
herpesvirus antigens
– viral factors: viral gene expression
– understand the impact of herpesvirus interactions
• Novel targets: tailored drug therapy, selective
immunosuppression, immunosuppression with co-existing
antiviral activity
• Novel preventive strategies
– vaccine strategies: DNA vaccine, multi-epitope vaccines
– cell-mediated therapeutic modalities
61