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Encyclopedia > Progressive multifocal leukoencephalopathy

This article is about the viral disease. For leukoencephalopathy caused by toxins, see toxic leukoencephalopathy. Toxic leukoencephalopathy is a rare but disturbingly debilitating and/or fatal condition suffered by some people who take heroin by chasing the dragon (inhaling the vapour ( the smoke ) of this drug off of a heated piece of aluminum foil) . The most obvious signs of this brain disorder are difficulty with...

Progressive multifocal leukoencephalopathy
Classification & external resources
ICD-10 A81.2
ICD-9 046.3

Progressive multifocal leukoencephalopathy (PML), also known as progressive multifocal leukoencephalitis, is a rare and usually fatal viral disease that is characterized by progressive damage (-pathy) or inflammation (-itis) of the white matter (leuko-) of the brain (-encephalo-) at multiple locations (multifocal). It occurs almost exclusively in people with severe immune deficiency, e.g. transplant patients on immunosuppressive medications, or AIDS patients. The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify diseases and a wide variety of signs, symptoms, abnormal findings, complaints, social circumstances and external causes of injury or disease. ... The International Statistical Classification of Diseases and Related Health Problems 10th Revision (ICD-10) is a coding of diseases and signs, symptoms, abnormal findings, complaints, social circumstances and external causes of injury or diseases, as classified by the World Health Organization (WHO). ... // A00-A79 - Bacterial infections, and other intestinal infectious diseases, and STDs (A00-A09) Intestinal infectious diseases (A00) Cholera (A01) Typhoid and paratyphoid fevers (A010) Typhoid fever (A02) Other Salmonella infections (A03) Shigellosis (A04) Other bacterial intestinal infections (A040) Enteropathogenic Escherichia coli infection (A045) Campylobacter enteritis (A046) Enteritis due to Yersinia... The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify diseases and a wide variety of signs, symptoms, abnormal findings, complaints, social circumstances and external causes of injury or disease. ... The following is a list of codes for International Statistical Classification of Diseases and Related Health Problems. ... This article is about biological infectious particles. ... An abscess on the skin, showing the redness and swelling characteristic of inflammation. ... White matter is one of the two main solid components of the central nervous system. ... For other uses, see Brain (disambiguation). ... In medicine, immune deficiency (or immunodeficiency) is a state where the immune system is incapable of defending the organism from infectious disease. ... Immunosuppression is the medical suppression of the immune system. ... Acquired Immune Deficiency Syndrome or acquired immunodeficiency syndrome (AIDS or Aids) is a collection of symptoms and infections resulting from the specific damage to the immune system caused by the human immunodeficiency virus (HIV). ...

Contents

Cause and epidemiology

The cause of PML is a type of polyomavirus called the JC virus (JCV), after the initials of the patient in whom it was first discovered. The virus is widespread, with 86% of the general population presenting antibodies, but it usually remains latent, causing disease only when the immune system has been severely weakened. Species See text Polyomavirus is the sole genus of viruses within the family Polyomaviridae. ... The JC virus (JCV) is a type of human polyomavirus (formerly known as papovavirus) and is genetically similar to BK virus and SV40. ... This article is about biological infectious particles. ...


About 2-5% of AIDS patients develop PML. It is unclear why PML occurs more frequently in AIDS than in other immunosuppressive conditions; some research suggests that the effects of HIV on brain tissue, or on JCV itself, make JCV more likely to become active in the brain and increase its damaging inflammatory effects (Berger, 2003).


There are case reports of PML being caused by pharmacological agents, although there is some speculation this could be due in part to the existing impaired immune response or 'pharm combos' rather than individual drugs. Rituxan([1] and Natalizumab (branded Tysabri), [2].


Disease process

PML is a demyelinating disease, in which the myelin sheath covering the axons of nerve cells is gradually destroyed, impairing the transmission of nerve impulses. It affects the white matter, which is mostly composed of axons from the outermost parts of the brain (cortex). Symptoms include weakness or paralysis, vision loss, impaired speech, and cognitive deterioration. PML is similar to another demyelinating disease, multiple sclerosis, but since it destroys the cells that produce myelin (unlike MS, in which myelin itself is attacked but can be replaced), it progresses much more quickly. Most patients die within four months of onset. PML destroys oligodendrocytes and produces intranuclear inclusions. A demyelinating disease is any disease of the nervous system in which the myelin sheath of neurons is damaged. ... Myelin is an electrically insulating phospholipid layer that surrounds the axons of many neurons. ... An axon or nerve fiber, is a long, slender projection of a nerve cell, or neuron, that conducts electrical impulses away from the neurons cell body or soma. ... Location of the cerebral cortex Slice of the cerebral cortex, ca. ... Oligodendrocytes (from Greek literally meaning few tree cells), or oligodendroglia (Greek, few tree glue),[1] are a variety of neuroglia. ...


Diagnosis

PML is diagnosed by testing for JC virus DNA in cerebrospinal fluid or in a brain biopsy specimen. Characteristic evidence of the damage caused by PML in the brain can also be detected on MRI images. The structure of part of a DNA double helix Deoxyribonucleic acid, or DNA, is a nucleic acid molecule that contains the genetic instructions used in the development and functioning of all known living organisms. ... Cerebrospinal fluid (CSF), Liquor cerebrospinalis, is a clear bodily fluid that occupies the subarachnoid space in the brain (the space between the skull and the cerebral cortex—more specifically, between the arachnoid and pia layers of the meninges). ... Brain biopsy A biopsy (in Greek: bios = life and opsy = look/appearance) is a medical test involving the removal of cells or tissues for examination. ... “MRI” redirects here. ...


Treatment

There is no known cure. In some cases, the disease slows or stops if the patient's immune system improves; some AIDS patients with PML have been able to survive for several years, with the advent of highly active antiretroviral therapy (HAART). A scanning electron microscope image of a single neutrophil (yellow), engulfing anthrax bacteria (orange). ... Antiretroviral drugs are medications for the treatment of infection by retroviruses, primarily HIV. Different classes of antiretroviral drugs act at different stages of the HIV life cycle. ...


AIDS patients who start HAART after being diagnosed with PML tend to have a slightly longer survival time than patients who were already on HAART and then develop PML (Wyen et al., 2004). A rare complication of effective HAART is immune reconstitution inflammatory syndrome (IRIS), in which increased immune system activity actually increases the damage caused by the infection; though IRIS is often manageable with other types of infections, it is extremely dangerous if it occurs in PML (Vendrely et al., 2005). Immune reconstitution inflammatory syndrome (IRIS) or immune reconstitution syndrome (IRS) is a rare condition seen in some cases of AIDS or immunosuppression, in which the immune system begins to recover, but then responds to a previously acquired opportunistic infection with an overwhelming inflammatory response that paradoxically makes the symptoms of...


Other antiviral agents that have been studied as possible treatments for PML include cidofovir and interleukin-2, but this research is still preliminary. Cidofovir is an injectable antiviral medication for the treatment of cytomegalovirus (CMV) retinitis in patients with AIDS. It suppresses CMV replication by selective inhibition of viral DNA synthesis. ... Interleukin-2 (IL2) is an interleukin, a type of biological response modifier that can improve the bodys natural response to disease. ...


Cytarabine (A.K.A. ARA-C), a chemotherapy drug approved by the US FDA to treat certain cancers, has been prescribed on an experimental basis for a small number of non-AIDS PML patients. Cytarabine is reported to have stabilized the neurological condition of a minority of these patients (Aksamit, 2001). One patient regained some cognitive function lost by PML (Langer-Gould et al., 2005).


References

  • Aksamit, A. J. (2001) Treatment of non-AIDS progressive multifocal leukoencephalopathy with cytosin arabinoside. J Neurovirol 2001;7:386.
  • Berger, J.R. (2003) Progressive multifocal leukoencephalopathy in acquired immunodeficiency syndrome: explaining the high incidence and disproportionate frequency of the illness relative to other immunosuppressive conditions. Journal of Neurovirology 9 (supplement), 38-41. PMID 12709870
  • Langer-Gould, A., Atlas, S. W., Bollen, A. W., Pelletier, D. (2005) Progressive Multifocal Leukoencephalopathy in a Patient Treated with Natalizumab. N Engl J Med 2005;353:375-81.
  • Vendrely, A., Bienvenu, B., Gasnault, J., Thiebault, J.B., Salmon, D. and Gray, F. (2005) Fulminant inflammatory leukoencephalopathy associated with HAART-induced immune restoration in AIDS-related progressive multifocal leukoencephalopathy. Acta Neuropathologica 109, 449-455. PMID 15739098
  • Wyen, C., Hoffmann, C., Schmeisser, N., Wohrmann, A., Qurishi, N., Rockstroh, J., Esser, S., Rieke, A., Ross, B., Lorenzen, T., Schmitz, K., Stenzel, W., Salzberger, B. and Fatkenheuer, G. (2004) Progressive multifocal leukencephalopathy in patients on highly active antiretroviral therapy: survival and risk factors of death. Journal of Acquired Immune Deficiency Syndrome 37, 1263-1268. PMID 15385733

See also

  • Leukoencephalopathy with vanishing white matter

Leukoencephalopathy with vanishing white matter (VWM disease) is an autosomal recessive neurological disease. ...

External links


  Results from FactBites:
 
Progressive multifocal leukoencephalopathy - definition of Progressive multifocal leukoencephalopathy in Encyclopedia (317 words)
Progressive multifocal leukoencephalopathy (PML), also known as progressive multifocal leukoencephalitis, is a rare and usually fatal disorder that is characterized by progressive damage (-pathy) or inflammation (-itis) of the white matter (leuko-) of the brain (-encephalo-) at multiple locations (multifocal).
PML is a demyelinating disease, in which the myelin sheath covering the axons of nerve cells is gradually destroyed, impairing the transmission of nerve impulses.
PML is similar to another demyelinating disease, multiple sclerosis, but since it destroys the cells that produce myelin (unlike MS, in which myelin itself is attacked but can be replaced), it progresses much more quickly.
Progressive multifocal leukoencephalopathy - Wikipedia, the free encyclopedia (608 words)
Progressive multifocal leukoencephalopathy (PML), also known as progressive multifocal leukoencephalitis, is a rare and usually fatal viral disease that is characterized by progressive damage (-pathy) or inflammation (-itis) of the white matter (leuko-) of the brain (-encephalo-) at multiple locations (multifocal).
The cause of PML is a type of polyomavirus called the JC virus (JCV), after the initials of the patient in whom it was first discovered.
Berger, J.R. (2003) Progressive multifocal leukoencephalopathy in acquired immunodeficiency syndrome: explaining the high incidence and disproportionate frequency of the illness relative to other immunosuppressive conditions.
  More results at FactBites »

 
 

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