CMV

Question 1

INFECTION VERSUS DISEASE

Answer 1

CMV infection:

virus isolation or detection of viral proteins (antigens) or nucleic acid in any body fluid or tissue specimen regardless of symptoms or signs.

CMV disease:

evidence of CMV infection with attributable symptoms or signs; CMV disease may manifest as either a viral syndrome (eg, fever, malaise, leukopenia, neutropenia, atypical lymphocytosis, thrombocytopenia)

or as tissue invasive disease

Question 2

IMMUNOCOMPROMISED HOSTS

Answer 2

Solid organ transplantation, hematopoietic cell transplantation, HIV infection, or the use of immunomodulating drugs.

Diagnostic approach similar in all.

Question 3

Diagnosis

Answer 3

Serology ( IgM, IgG)

Qualitative and quantitative polymerase chain reaction (PCR),

pp65 antigenemia,

Culture, and

Histopathology

Question 4

Viral load

Answer 4

Initial viral load:

For predicting CMV disease - 2000 to 5000 copies/mL of plasma.

Rate of increase:

Used predict which patients are at risk for CMV disease

Question 5

Testing based on type of disease

Answer 5

Viral syndrome: Quantitative CMV PCR and antigenemia assays

Tissue invasive disease : CMV inclusions or positive CMV-specific immunohistochemistry staining on histopathology. + PCR, Serology

Pneumonitis:Inclusions in cells from BAL or lung biopsy+ PCR,serology

lung transplant recipients, quantitative CMV PCR on BAL specimens

Gastrointestinal: stool specimens has no role, multiple biopsies to confirm colitis or esophagitis. cannot be excluded based on a negative plasma or whole blood PCR

Central nervous system disease:Viral load testing of CSF.

Question 6

Monitoring response to treatment

Answer 6

A baseline viral load should be obtained the day that antiviral therapy is initiated and should be repeated weekly.

Give treatment doses of an antiviral agent until the CMV load is negative.

Ganciclovir resistance may have persistently elevated viral load values.

Resistance to ganciclovir - Foscarnet/Cidofovir Rx.