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Unit Code 81107:
JC Virus (JCV) Detection by In Situ Hybridization

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Useful For

Confirming a clinical and histopathologic diagnosis of PML; especially

helpful when only a small piece of biopsy material is available

Clinical Information

JCV was isolated from brain tissue of a patient with progressive

multifocal leukoencephalopathy (PML), a rare, demyelinating, fatal

disorder of the central nervous system which occurs on a background

of immune deficiency. PML occurs as an infrequent complication of

a wide variety of conditions, including:  lymphoproliferative disorders

such as Hodgkin's disease, chronic lymphocytic leukemia, and

lymphosarcoma; chronic diseases such as sarcoidosis and

tuberculosis, and primary immunodeficiency diseases. PML has

also been recognized as a frequent complication of the acquired

immunodeficiency syndrome (AIDS). Most cases of PML, not

associated with AIDS, occur in middle age or later life, but the

disease may occur in an immunocompromised individual of any

age and has been recognized in young children with

immunodeficiency diseases.

 

JCV also infects humans in childhood and is present in most of

the world's population. It is the etiologic agent of PML. Clinically,

signs and symptoms of asymmetric multifocal brain disease without

signs of increased intracranial pressure in a person who is

immunocompromised would suggest the diagnosis of PML.

Computed tomographic scan or magnetic resonance imaging of the

brain is effective in establishing the diagnosis of PML in a noninvasive

manner. The unique histopathologic features of PML can be identified

by light microscopy of a brain biopsy specimen. JCV can be cultivated

in cell cultures, and serologic assays have have been developed, but

nucleic acid detection methods are much more sensitive and rapid for

making the laboratory diagnosis of PML using brain tissue.

Reference Values

This test, when not accompanied by a pathology consultation

request, will be answered as either positive or negative.

If additional interpretation/analysis is needed, please request

#5439 "Surgical Pathology Consultation" along with this test.

Interpretation

"Positive for Polyomavirus (JC Virus)" indicates the presence of

infection with JCV.

 

"Negative for Polyomavirus (JC Virus)" indicates the absence of

cells infected with JCV.

 

A negative result is normal.

Cautions

Prolonged formalin fixation may cause false-negative results.

A few weeks appears to be the maximum time of fixation.

 

Submitted specimens will be screened by a pathologist to determine

the acceptability of the specimen for the test.

 

Slides must be specially prepared, therefore, a paraffin-embedded,

formalin-fixed tissue must also be submitted.

Clinical Reference

1.   Aksamit AJ, Mourrain P, Sever JL, Major EO:  Progressive multifocal

      leukoencephalopathy: investigation of three cases using in situ              

      hybridization with JC virus biotinylated DNA probe. Ann Neurol

      1985;18:490-496

 

2.   Telenti A, Aksamit AJ Jr, Proper J, Smith TF:  Detection of JC virus

      DNA by polymerase chain reaction in patients with progressive

      multifocal leukoencephalopathy. J Infect Dis 1990;162:858-861

 

3.   Aksamit AJ Jr:  Nonradioactive in situ hybridization in progressive

      multifocal leukoencephalopathy. Mayo Clin Proc 1993;68:899-910

Key