antibodies

Question 1

What is autoimmune encephalitis?

Answer 1

Autoimmune encephalitis is a group of encephalitis syndromes that cause altered mentality, memory decline, or seizures in association with the presence of serum and cerebrospinal fluid (CSF) autoantibodies (auto-Abs). An early diagnosis enables early treatments.

Question 2

How are antibodies tested?

Answer 2

The detection of auto-Abs is a confirmatory diagnosis. Tissue-based assay, cell-based immunoassay, and immunoblotting are used to detect various autoantibodies. The CSF test for the presence of antibodies is important because it is more sensitive and reflects disease activity in many autoimmune encephalitis, although antibody tests can be negative even in the presence of autoimmune encephalitis.

Question 3

What are the common cancers associated with Hu?

Answer 3

SCLC, neuroendocrine tumors

Question 4

What are the common cancers associated with Yo?

Answer 4

Ovary, breast cancer

Question 5

What are the common cancers associated with CV2/CRMP5?

Answer 5

SCLC, thymoma

Question 6

What are the common cancers associated with Ma2?

Answer 6

Testicular, breast cancer, lung cancer, stomach cancer

Question 7

What are the common cancers associated with Amphiphysin?

Answer 7

Breast cancer, SCLC

Question 8

What are the common cancers associated with Recoverin?

Answer 8

SCLC, NSCLC

Question 9

What are the common cancers associated with NMDA receptor?

Answer 9

Ovarian or mediastinal teratoma

Question 10

What are the common cancers associated with LGI1?

Answer 10

Thymoma, lung cancer,

Question 11

What are the common cancers associated with Caspr2?

Answer 11

Thymoma

Question 12

What are the common cancers associated with GABA B receptor?

Answer 12

SCLC

Question 13

What are the common cancers associated with GABA A receptor?

Answer 13

Rare

Question 14

What are the common cancers associated with AMPA receptor?

Answer 14

Lung, breast cancer, thymoma

Question 15

What are reasons for negative Ab test?

Answer 15

-antigen denaturation during tissue fixation
-false-negative results caused by a small amount of Ab
-differences between human and mouse epitopes
-the presence of T-cell-dominant autoimmune encephalitis.

Question 16

What is the process of classic paraneoplastic or onconeuronal autoantibodies?

Answer 16

These target intracellular neuronal epitopes are not thought to be directly pathogenic. These antibodies target diverse proteins that do not predict the associated neurologic symptoms.

Question 17

What is ‘encephalopathy’?

Answer 17

Encephalopathy = (altered consciousness persisting for longer than 24 h, including lethargy, irritability or a change in personality or behaviour)

Question 18

What is ‘encephalitis’?

Answer 18

Encephalitis = encephalopathy AND evidence of CNS inflammation, demonstrated by at least two of:
fever
seizures or focal neurological findings attributable to the brain parenchyma
CSF pleocytosis (more than 4 white cells per μL)
EEG findings suggestive of encephalitis
neuroimaging findings suggestive of encephalitis.

Question 19

What are some causes of encephalitis?

Answer 19

Viral: Herpes simplex virus types 1 and 2, varicella zoster virus, enteroviruses, adenovirus, parechovirus, measles virus, HIV

Autoimmune -Antibodies against neuronal surface antigens: NMDAR antibody encephalitis (ovarian teratoma),
LGI-1 antibody encephalitis (thymoma),
antibodies against intracellular antigens: anti-Hu (small cell lung tumour), anti-Ma (testicular tumours), anti-GAD, acute disseminated encephalomyelitis, Bickerstaff’s encephalitis

Question 20

What are some mimics of encephalitis?

Answer 20

Infective: Systemic sepsis with encephalopathy, bacterial meningitis, TB, opportunistic infections in immunocompromised patients (eg crytococcus, toxoplasma, cytomegalovirus)
Inflammatory: Vasculitis, systemic lupus erythematosus with CNS involvement, Behçet’s disease, neurosarcoidosis
Metabolic: Hypoglycaemia, hyponatraemia, hepatic encephalopathy, toxins (drugs, alcohol)
Neoplastic: Primary brain tumour (particularly low grade glioma mimicking CNS inflammation), metastases
Others: Status epilepticus from other causes, haemorrhagic or ischaemic stroke, psychiatric disease

Question 21

What is ADEM?

Answer 21

-Acute disseminated encephalomyelitis (ADEM) causes an attack of inflammation in the brain and spinal cord that damages myelin. A common cause of ADEM is myelin oligodendrocyte (MOG) antibody. -Treatment is targeted at suppressing the immune system and reducing inflammation using anti-inflammatory drugs such as corticosteroids

Question 22

What is encephalitis lethargica?

Answer 22

Encephalitis lethargica is a rare disease with no known cause, but researchers suspect it may come from a virus. There was a pandemic of encephalitis lethargica (known then as “sleeping sickness”) from around 1916 to 1930, but no recurrence of the epidemic has since been reported.

Question 23

What is HSE?

Answer 23

-Herpes simplex encephalitis (HSE) is responsible for about 10% of all encephalitis cases.
-Most cases are caused by reactivation of an earlier infection with the herpes simplex virus, but some cases result from initial infection

Question 24

What is eastern equine encephalitis?

Answer 24

mostly occurs in the eastern U.S. with a few cases seen in the Great Lakes region. Only a few cases are seen annually in the United States. It mainly affects young children and adults over age 55. Symptoms are seen within four days or up to two weeks following transmission through the bite of an infected mosquito and include sudden fever, general flu-like muscle pains, and headache of increasing severity, followed by coma and death in severe cases.

Question 25

What is Western equine encephalitis?

Answer 25

seen in farming areas in the western and central plains states. Symptoms begin within five to 10 days following infection. Children, particularly those under a year old, are affected more severely than adults and may have permanent neurologic damage.

Question 26

What is La Crosse encephalitis?

Answer 26

LaCrosse encephalitis typically occurs in the upper midwestern states but also has been reported in the southeastern and mid-Atlantic regions of the U.S. Most cases affect children under age 16. Symptoms, such as vomiting, headache, fever, and lethargy, appear up to 10 days following infection. Severe complications include seizures, coma, and permanent brain damage. About 100 cases of LaCrosse encephalitis are reported each year.

Question 27

What is Subacute sclerosing panencephalitis (SSPE)?

Question 28

What is limbic encephalitis?

Answer 28

Limbic encephalitis causes inflammation of the limbic system (the parts of the brain that control your emotions, behavior, motivation, and memory) and other parts of the brain. Symptoms of limbic encephalitis include confusion, memory loss, sleep disturbances, psychiatric symptoms (altered personality or behavior), and seizures.

Question 29

What is NMDAR encephalitis?

Answer 29

NMDA receptor antibody encephalitis or anti-NMDA receptor encephalitis occurs when the immune system makes antibodies that mistakenly attack proteins on the surface of nerve cells called NMDA (N-methyl-D-aspartate) receptors. Antibodies, also called immunoglobulins, are proteins which identify and help remove viruses and bacteria. This type of encephalitis has become more common