Canterbury DHB

Acquired CMV Infection - Treatment

For general information about CMV, see UpToDate website.

Clinical Features

These are extremely variable.

• The CMV Mononucleosis Syndrome presents with fever and malaise, atypical lymphocytes in the blood, and altered liver function tests. There is less pharyngitis and splenomegaly compared to an EBV infection.
• Post-transfusion CMV infection may occur and has an incubation period of 20-60 days. This is now rare since all blood products are leucodepleted.
• CMV is also common in immunosuppressed patients. The presentation is varied with the lungs, GI tract, and retina being sites most often involved. Pneumonitis may resemble pneumocystis pneumonia, with fever, dry cough, dyspnoea, and hypoxia with bilateral pulmonary shadowing. GI tract CMV disease can cause upper and lower GI symptoms as well as pancreatitis, hepatitis and cholecystitis. Retinitis leads to visual impairment with white perivascular retinal infiltrates. It may progress to blindness if treatment is not started promptly.

Diagnosis

The diagnostic test currently recommended is Q-PCR for CMV DNA on plasma and white blood cells. The results are now reported in International Units per litre (IU/L).

Take 5 mL blood into EDTA (mauve top) tube. This will detect CMV viral DNA, and give a measure of the viral load present. Repeat testing can be used to monitor progression or the effectiveness of treatment.

Treatment

• The decision to treat a possible CMV infection requires the integration of clinical and laboratory findings. It is essential to get an Infectious Disease Service consultation at this point.
• There is no consensus about what level of CMV DNA requires treatment. A randomised trial suggests a level of 15,000 IU/mL (10,000 copies/mL) is a safe level [see BCSH guideline below]. The rate of rise of CMV may also be important. A small level of CMV reactivation may be advantageous to allow a host immune response to occur.

  It is suggested that if the absolute level of CMV reaches 1500 copies/mL (1000 IU/ mL) or rises by more than 1-log on successive samples, that the result is discussed with the patient’s named transplant consultant in Christchurch.

  • The current unit of measurement for CMV DNA is IU/mL. The current assay has a conversion factor of 0.64 to convert to copies/mL. For example: IU/mL x 0.64 = copies/mL

    IU/mL	Copies/mL
    1	0.64
    1500	960
    5000	3200
    10000	6400
    15000	9600

• Apart from general supportive care, the initial treatment of choice is ganciclovir, usually in a dose of 5 mg/kg IV q12h.
• Dosage adjustment may be required in renal failure. Please seek advice from the pharmacist.
• Other drugs that can be used include foscarnet, cidofovir, and IV immunoglobulin.

See:

• BCSH guideline – Emery, V., M. Zuckerman, et al. (2013). "Management of cytomegalovirus infection in haemopoietic stem cell transplantation." Br J Haematol 162(1): 25-39.
• Patient information leaflet – Anthony Nolan Patient information – life after transplant: An essential guide to dealing with infections.
• General information about CMV Infections – UpToDate website.

Note: Oral valganciclovir is also available. For more information, see the valganciclovir Data Sheets on Medsafe.

Foscarnet

Foscarnet may be used in place of ganciclovir when ganciclovir marrow suppression is present:

• Prophylactic dose = 90 mg/kg/day 5 x a week
• Treatment dose = 180 mg/kg/day

The major complication of foscarnet is electrolyte disturbance which needs to be checked daily, including magnesium and phosphate.

For more information about foscarnet, refer to the Data Sheets on Medsafe.

Topic Code: 5030