Clinical and Interpretive

STRATIFY JCV® DxSelect™ Antibody (with Index) with Reflex to Inhibition - 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]

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.

References:
1. Lee P, Plavina T, Castro A, et al. A second-generation ELISA (STRATIFY JCV DxSelect) for detection of JC virus antibodies in human serum and plasma to support progressive multifocal leukoencephalopathy risk stratification. J clin Virol. 2013; 57 (2): 141-146. Doi: 10.1016/j. jcv. 2013.02. 002
2. Us package insert, STRATIFY JCV® DxSelect™ EL1950-5 Rev. 03 dated 16 Dec 2022