JC Virus Antibody with Reflex to Inhibition Assay (Sendout)

Clinical Significance: This assay is a qualitative assay for the detection of antibodies to JC virus (JCV) in human serum or plasma. This assay was designed and evaluated for use, in conjunction with other clinical data, as an aid in the stratification of risk for the development of progressive multifocal leukoencephalopathy (PML) in multiple sclerosis (MS) patients receiving or considering TYSABRI® (natalizumab) therapy. [1]

The PML risk-estimate algorithm for TYSABRI was developed based on data collected from patients taking TYSABRI. [2]

PML is a severe demyelinating disease of the central nervous system. It is an opportunistic infection caused by reactivation of JCV. Asymptomatic primary infection with JCV typically occurs prior to adolescence. In most individuals, JCV remains latent and causes no symptoms. In rare instances, however, it can reactivate and progress to PML. Individuals with immunosuppression are most at risk, and use of immunosuppressive therapies increases the risk. To date, the known risk factors for natalizumab-associated PML are: 1) presence of anti-JCV antibodies; 2) prior use of immunosuppressants; 3) duration of natalizumab use. [2]

Test Algorithm: If the Index Value is between 0.20-0.40 (inclusive), then STRATIFY JCV® DxSelect™ Antibody Inhibition Assay will be performed.

A positive result with this assay does not necessarily mean that the patient has or will develop PML.

This assay should not be used to diagnose PML and is not intended for donor screening. The performance of this assay has not been established for use in other immunocompromised patient populations or in neonates and pediatric patient populations.

The performance of this assay has not been established for use with patients with different disease conditions or undergoing other treatments, for example: Other MS treatments, non-Hodgkin lymphoma treatments, chronic lymphocytic leukemia treatments, Hodgkin lymphoma treatments, systemic anaplastic large cell lymphoma treatments, rheumatoid arthritis treatments, renal transplant treatments.

2 mL blood in a RED TOP tube or GOLD SST

• Alternative Specimen: LAVENDER TOP (EDTA) tube

Outside Laboratories: Centrifuge sample and transfer serum or plasma to a separate plastic vial. Refrigerate sample while awaiting shipment. Transport with a cold pack.

Stability: Refrigerated (preferred): 14 days; Frozen: 90 days; Ambient: 7 days.

Reject Criteria: Gross hemolysis, grossly lipemic, or grossly icteric.

Centrifuge sample and transfer serum or plasma to a separate plastic vial. Refrigerate sample.

Sendouts:

• Order Quest SJC Test: 91665
• QuestQuanum Ask at Order Entry Question: Natalizumab Therapy?
  • Select "Not Applicable" from the drop-down menu.

Stability: Refrigerated (preferred): 14 days; Frozen: 90 days; Ambient: 7 days.

Reject Criteria: Gross hemolysis, grossly lipemic, or grossly icteric.