Progressive inflammatory neuropathy

Last updated
Progressive inflammatory neuropathy
Specialty Neurology, immunology

Progressive inflammatory neuropathy is a autoimmune disease that was identified in a report, released on January 31, 2008, by the Centers for Disease Control and Prevention. [1] The first known outbreak of this neuropathy occurred in southeastern Minnesota in the United States. The disease was reported among slaughterhouse workers who appeared at various care facilities in the area reporting similar neurological symptoms. [2] [3] The disease was later identified at slaughterhouses in Indiana and Nebraska as well. [4] The condition is characterized by acute paralysis, pain, fatigue, numbness, and weakness, especially in extremities. [5] [6] It was initially believed that workers might have contracted the disease through inhaling aerosols from pig brains that were created by a machine at the slaughterhouse and that an autoimmune response to the particles might have produced their mysterious peripheral neuropathy. [1] These suspicions were confirmed in reports and investigations conducted at the Mayo Clinic in Rochester, Minnesota. [6] [7] [8] [9]

Contents

Cause

An initial comprehensive study of 24 known cases was conducted by multiple doctors from various disciplines at the Mayo Clinic. They identified the cause of this neurological disease to be long-term occupational exposure to aerosolized porcine brain and spinal tissue. [8] Investigators from the Minnesota Department of Health simultaneously determined that the air pressure jet system used to extract the brain from pig carcasses was unsafe, as it would create an airborne mist of pig organs. [1] [2] [4] The workers closest in proximity to the "head table", an area in the factory where the air system was used, were the most likely to be affected. [4] The aerosolized mist was readily absorbed into the workers' nasal mucosa. The pig proteins were then recognized by their bodies as foreign and an autoimmune response was initiated. [5] [6] [7] [8] [9] Researchers determined that the disease was due to the voltage-gated potassium channels being blocked by autoantibodies that are induced by pig brain antigen exposure, causing an intracellular build-up of potassium ions which causes inflammation and irritation, and consequently, hyper-excitability in the peripheral nervous system. It is this hyper-excitability that leads to the tingling, numbness, pain, and weakness. [9]

Researchers from the Mayo Clinic developed an animal model that involved mice receiving twice daily doses of minced pig brain tissue in saline intranasally. Biochemical testing indicated the signature autoantibodies (potassium channel antibodies, myelin basic protein antibodies and calcium channel antibodies) were present in experimental mice. [6] This animal model confirmed the hypothesized mechanism of progressive inflammatory neuropathy.

Diagnosis

Over 40 laboratory tests were initially conducted to rule out various pathogens and environmental toxins. These tests were used to try to identify potential viruses carried by humans, pigs, or both, including rotaviruses, adenoviruses, hepatitis A, and hepatitis E. Investigeators also tried to identify bacteria such as Salmonella and Escherichia coli, and parasites such as Giardia and Cryptosporidium that could be causing the symptoms. All of these infectious causes were ruled out. [4] [10]

Prion associated diseases such as bovine spongiform encephalopathy (BSE), chronic wasting disease (CWD), and variant Creutzfeldt–Jakob disease were also quickly ruled out as being the cause of this neuropathy. [3] [10] [1] [4]

Next two very similar autoimmune neuropathies were ruled out: Guillain–Barré syndrome is an acute autoimmune response which affects the Schwann cells in the peripheral nervous system. Guillain–Barré syndrome is usually triggered by a recent infection (or more rarely a recent vaccination) and causes weakness and tingling in the arms and legs. [2] Researchers also looked at chronic inflammatory demyelinating polyneuropathy which is characterized by progressive weakness and sensory impairment in the arms and legs. Damage occurs to the myelin sheathing in the peripheral nervous system. [3] However, as doctors at the Mayo Clinic were beginning to note, the problem they were seeing in progressive inflammatory neuropathy was occurring in the spinal nerve roots. [9]

Treatment and history

In October 2007 an astute medical interpreter noticed similar neurological symptoms being reported by Spanish-speaking patients seeking treatment from different physicians at the Austin Medical Center, in Austin, Minnesota. [11] Not only did these patients share similar neurological symptoms, they also worked at the same slaughterhouse. [4] [6] [8] [11] Dr. Daniel LaChance, a physician at both the Austin Medical Center and the Mayo Clinic in nearby Rochester, Minnesota, was notified. He launched a request to area physicians to refer other patients with similar symptoms to him. [11] The Minnesota Department of Health was notified and began an investigation into the "outbreak." [1] They identified workers from two other pork facilities in Indiana and Nebraska who also had parallel neurological complaints. Several agencies including the Occupational Safety and Health Administration and the Centers for Disease Control and Prevention were brought in to assist. Simultaneously investigations were conducted to rule out contagious disease, to locate the source or carrier, and to identify what exactly was causing these workers to develop these symptoms. [4]

Removal from exposure was the first line of treatment. Due to the progressive sensory loss and weakness, various medications were often required. These included intravenous methylprednisolone, oral prednisone, azathioprine, and/or IVIG. [7] All 24 patients improved, including 7 who received no treatment and 17 who required immunosuppressive drugs. [7] [8]

Prognosis

It is expected that there will be no new cases of progressive inflammatory neuropathy since this particular carcass processing method has been discontinued. [2] [12]

See also

Related Research Articles

Neuromyotonia (NMT) is a form of peripheral nerve hyperexcitability that causes spontaneous muscular activity resulting from repetitive motor unit action potentials of peripheral origin. NMT along with Morvan's syndrome are the most severe types in the Peripheral Nerve Hyperexciteability spectrum. Example of two more common and less severe syndromes in the spectrum are cramp fasciculation syndrome and benign fasciculation syndrome. NMT can have both hereditary and acquired (non-inherited) forms. The prevalence of NMT is unknown.

<span class="mw-page-title-main">Myalgia</span> Painful sensations in muscle tissue

Myalgia or muscle pain is a painful sensation evolving from muscle tissue. It is a symptom of many diseases. The most common cause of acute myalgia is the overuse of a muscle or group of muscles; another likely cause is viral infection, especially when there has been no injury.

Myelitis is inflammation of the spinal cord which can disrupt the normal responses from the brain to the rest of the body, and from the rest of the body to the brain. Inflammation in the spinal cord can cause the myelin and axon to be damaged resulting in symptoms such as paralysis and sensory loss. Myelitis is classified to several categories depending on the area or the cause of the lesion; however, any inflammatory attack on the spinal cord is often referred to as transverse myelitis.

<span class="mw-page-title-main">Somatic nervous system</span> Part of the peripheral nervous system

The somatic nervous system (SNS), also known as voluntary nervous system, is a part of the peripheral nervous system (PNS) that links brain and spinal cord to skeletal muscles under conscious control, as well as to sensory receptors in the skin. The other part complementary to the somatic nervous system is the autonomic nervous system (ANS).

<span class="mw-page-title-main">Dysautonomia</span> Any disease or malfunction of the autonomic nervous system

Dysautonomia, autonomic failure, or autonomic dysfunction is a condition in which the autonomic nervous system (ANS) does not work properly. This may affect the functioning of the heart, bladder, intestines, sweat glands, pupils, and blood vessels. Dysautonomia has many causes, not all of which may be classified as neuropathic. A number of conditions can feature dysautonomia, such as Parkinson's disease, multiple system atrophy, dementia with Lewy bodies, Ehlers–Danlos syndromes, autoimmune autonomic ganglionopathy and autonomic neuropathy, HIV/AIDS, mitochondrial cytopathy, pure autonomic failure, autism, and postural orthostatic tachycardia syndrome.

<span class="mw-page-title-main">Peripheral neuropathy</span> Nervous system disease affecting nerves beyond the brain and spinal cord

Peripheral neuropathy, often shortened to neuropathy, refers to damage or disease affecting the nerves. Damage to nerves may impair sensation, movement, gland function, and/or organ function depending on which nerve fibers are affected. Neuropathies affecting motor, sensory, or autonomic nerve fibers result in different symptoms. More than one type of fiber may be affected simultaneously. Peripheral neuropathy may be acute or chronic, and may be reversible or permanent.

<span class="mw-page-title-main">Demyelinating disease</span> Any neurological disease in which the myelin sheath of neurons is damaged

A demyelinating disease refers to any disease affecting the nervous system where the myelin sheath surrounding neurons is damaged. This damage disrupts the transmission of signals through the affected nerves, resulting in a decrease in their conduction ability. Consequently, this reduction in conduction can lead to deficiencies in sensation, movement, cognition, or other functions depending on the nerves affected.

<span class="mw-page-title-main">Polyneuropathy</span> Any disease affecting peripheral nerves on both sides of the body

Polyneuropathy is damage or disease affecting peripheral nerves in roughly the same areas on both sides of the body, featuring weakness, numbness, and burning pain. It usually begins in the hands and feet and may progress to the arms and legs and sometimes to other parts of the body where it may affect the autonomic nervous system. It may be acute or chronic. A number of different disorders may cause polyneuropathy, including diabetes and some types of Guillain–Barré syndrome.

Astasis is a lack of motor coordination marked by an inability to stand, walk or even sit without assistance due to disruption of muscle coordination.

<span class="mw-page-title-main">Neuropathology</span> Study of disease of nervous system tissue

Neuropathology is the study of disease of nervous system tissue, usually in the form of either small surgical biopsies or whole-body autopsies. Neuropathologists usually work in a department of anatomic pathology, but work closely with the clinical disciplines of neurology, and neurosurgery, which often depend on neuropathology for a diagnosis. Neuropathology also relates to forensic pathology because brain disease or brain injury can be related to cause of death. Neuropathology should not be confused with neuropathy, which refers to disorders of the nerves themselves rather than the tissues. In neuropathology, the branches of the specializations of nervous system as well as the tissues come together into one field of study.

<span class="mw-page-title-main">Neuritis</span> Inflammation of a nerve or generally any part of the nervous system

Neuritis, from the Greek νεῦρον), is inflammation of a nerve or the general inflammation of the peripheral nervous system. Inflammation, and frequently concomitant demyelination, cause impaired transmission of neural signals and leads to aberrant nerve function. Neuritis is often conflated with neuropathy, a broad term describing any disease process which affects the peripheral nervous system. However, neuropathies may be due to either inflammatory or non-inflammatory causes, and the term encompasses any form of damage, degeneration, or dysfunction, while neuritis refers specifically to the inflammatory process.

<span class="mw-page-title-main">Chronic inflammatory demyelinating polyneuropathy</span> Medical condition

Chronic inflammatory demyelinating polyneuropathy (CIDP) is an acquired autoimmune disease of the peripheral nervous system characterized by progressive weakness and impaired sensory function in the legs and arms. The disorder is sometimes called chronic relapsing polyneuropathy (CRP) or chronic inflammatory demyelinating polyradiculoneuropathy. CIDP is closely related to Guillain–Barré syndrome and it is considered the chronic counterpart of that acute disease. Its symptoms are also similar to progressive inflammatory neuropathy. It is one of several types of neuropathy.

A paraneoplastic syndrome is a syndrome that is the consequence of a tumor in the body. It is specifically due to the production of chemical signaling molecules by tumor cells or by an immune response against the tumor. Unlike a mass effect, it is not due to the local presence of cancer cells.

Guillain–Barré syndrome (GBS) is a rapid-onset muscle weakness caused by the immune system damaging the peripheral nervous system. Typically, both sides of the body are involved, and the initial symptoms are changes in sensation or pain often in the back along with muscle weakness, beginning in the feet and hands, often spreading to the arms and upper body. The symptoms may develop over hours to a few weeks. During the acute phase, the disorder can be life-threatening, with about 15% of people developing weakness of the breathing muscles requiring mechanical ventilation. Some are affected by changes in the function of the autonomic nervous system, which can lead to dangerous abnormalities in heart rate and blood pressure.

<span class="mw-page-title-main">Central nervous system disease</span> Disease of the brain or spinal cord

Central nervous system diseases or central nervous system disorders are a group of neurological disorders that affect the structure or function of the brain or spinal cord, which collectively form the central nervous system (CNS). These disorders may be caused by such things as infection, injury, blood clots, age related degeneration, cancer, autoimmune disfunction, and birth defects. The symptoms vary widely, as do the treatments.

<span class="mw-page-title-main">Neurological disorder</span> Any disorder of the nervous system

A neurological disorder is any disorder of the nervous system. Structural, biochemical or electrical abnormalities in the brain, spinal cord or other nerves can result in a range of symptoms. Examples of symptoms include paralysis, muscle weakness, poor coordination, loss of sensation, seizures, confusion, pain, tauopathies, and altered levels of consciousness. There are many recognized neurological disorders, some are relatively common, but many are rare.

Behçet's disease is recognized as a disease that causes inflammatory perivasculitis, inflammation of the tissue around a blood or lymph vessel, in practically any tissue in the body. Usually, prevalent symptoms include canker sores or ulcers in the mouth and on the genitals, and inflammation in parts of the eye. In addition, patients experience severe headache and papulopustular skin lesions as well. The disease was first described in 1937 by a Turkish dermatologist, Dr. Hulusi Behçet. Behçet's disease is most prevalent in the Middle East and the Far East regions; however, it is rare in Western regions.

Blue eye disease is caused by La Piedad Michoacán Mexico virus (LPMV), the only member virus of the species Porcine orthorubulavirus in the Paramyxoviridae family. Synonyms for the disease include "Blue Eye Syndrome" and "Porcine Paramyxovirus Blue Eye Disease", and "La Piedad Michoacán Paramyxovirus Infection".

<span class="mw-page-title-main">Adult polyglucosan body disease</span> Medical condition

Adult polyglucosan body disease (APBD) is a rare monogenic glycogen storage disorder caused by an inborn error of metabolism. Symptoms can emerge any time after the age of 30. Early symptoms include trouble controlling urination, trouble walking, and lack of sensation in the legs. People eventually develop dementia.

Peripheral mononeuropathy is a nerve related disease where a single nerve, that is used to transport messages from the brain to the peripheral body, is diseased or damaged. Peripheral neuropathy is a general term that indicates any disorder of the peripheral nervous system. The name of the disorder itself can be broken down in order to understand this better; peripheral: in regard to peripheral neuropathy, refers to outside of the brain and spinal cord; neuro: means nerve related; -pathy; means disease. Peripheral mononeuropathy is a disorder that links to Peripheral Neuropathy, as it only effects a single peripheral nerve rather than several damaged or diseased nerves throughout the body. Healthy peripheral nerves are able to “carry messages from the brain and spinal cord to muscles, organs, and other body tissues”.

References

  1. 1 2 3 4 5 "Investigation of Progressive Inflammatory Neuropathy Among Swine Slaughterhouse Workers---Minnesota, 2007---2008". Centers for Disease Control and Prevention. 2007-01-31. Retrieved 2008-02-04.
  2. 1 2 3 4 Brown, David. "Inhaling pig brains may be cause of new illness" (PDF). Retrieved 20 March 2012.
  3. 1 2 3 Genoways, Ted. "The Spam Factory's Dirty Secret" . Retrieved 12 May 2012.
  4. 1 2 3 4 5 6 7 Holzbauer, Stacy. "Investigation into risk factors for progressive inflammatory neuropathy among swine abattoir workers in the united states" (PDF). Archived from the original (PDF) on 2 June 2013. Retrieved 1 May 2012.
  5. 1 2 DeAngelis, Tracy M.; Shen, Liang (1 October 2009). "Outbreak of Progressive Inflammatory Neuropathy Following Exposure to Aerosolized Porcine Neural Tissue". Mount Sinai Journal of Medicine: A Journal of Translational and Personalized Medicine. 76 (5): 442–447. doi:10.1002/msj.20132. PMID   19787653.
  6. 1 2 3 4 5 Rukovets, Olga. "Ani". mal model mirrors human form of occupational neuropathy in pork plant workers. Neurology Today. Archived from the original on 16 January 2013. Retrieved 19 March 2012.
  7. 1 2 3 4 Tracy, Jennifer A.; Dyck, P. James B. (1 June 2011). "Auto-immune polyradiculoneuropathy and a novel IgG biomarker in workers exposed to aerosolized porcine brain". Journal of the Peripheral Nervous System. 16: 34–37. doi:10.1111/j.1529-8027.2011.00303.x. PMID   21696495. S2CID   36231208.
  8. 1 2 3 4 5 Lachance, DH; Lennon, VA; Pittock, SJ; Tracy, JA; Krecke, KN; Amrami, KK; Poeschla, EM; Orenstein, R; Scheithauer, BW; Sejvar, JJ; Holzbauer, S; Devries, AS; Dyck, PJ (Jan 2010). "An outbreak of neurological autoimmunity with polyradiculoneuropathy in workers exposed to aerosolised porcine neural tissue: a descriptive study". Lancet Neurology. 9 (1): 55–66. doi:10.1016/S1474-4422(09)70296-0. PMID   19945916. S2CID   19696027.
  9. 1 2 3 4 Meeusen, Jeffrey W.; Klein, Christopher J.; Pirko, Istvan; Haselkorn, Keegan E.; Kryzer, Thomas J.; Pittock, Sean J.; Lachance, Daniel H.; Dyck, P. James; Lennon, Vanda A. (1 March 2012). "Potassium channel complex autoimmunity induced by inhaled brain tissue aerosol". Annals of Neurology. 71 (3): 417–426. doi:10.1002/ana.22674. PMC   3315155 . PMID   22451206.
  10. 1 2 Centers for Disease Control and Prevention (2 May 2008). "New brain disease is blowing minds" . Retrieved 1 March 2012.
  11. 1 2 3 Gajilan, A. "Medical mystery solved in slaughterhouse". Archived from the original on October 1, 2010. Retrieved 19 March 2012.
  12. ↑ National Center for Zoonotic, Vector-Borne, and Enteric Diseases. "Investigation of progressive inflammatory neuropathy among swine slaughterhouse workers" . Retrieved 1 March 2012.{{cite web}}: CS1 maint: multiple names: authors list (link)
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.