antibodies Flashcards
What is autoimmune encephalitis?
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.
How are antibodies tested?
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.
What are the common cancers associated with Hu?
SCLC, neuroendocrine tumors
What are the common cancers associated with Yo?
Ovary, breast cancer
What are the common cancers associated with CV2/CRMP5?
SCLC, thymoma
What are the common cancers associated with Ma2?
Testicular, breast cancer, lung cancer, stomach cancer
What are the common cancers associated with Amphiphysin?
Breast cancer, SCLC
What are the common cancers associated with Recoverin?
SCLC, NSCLC
What are the common cancers associated with NMDA receptor?
Ovarian or mediastinal teratoma
What are the common cancers associated with LGI1?
Thymoma, lung cancer,
What are the common cancers associated with Caspr2?
Thymoma
What are the common cancers associated with GABA B receptor?
SCLC
What are the common cancers associated with GABA A receptor?
Rare
What are the common cancers associated with AMPA receptor?
Lung, breast cancer, thymoma
What are reasons for negative Ab test?
-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.
What is the process of classic paraneoplastic or onconeuronal autoantibodies?
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.
What is ‘encephalopathy’?
Encephalopathy = (altered consciousness persisting for longer than 24 h, including lethargy, irritability or a change in personality or behaviour)
What is ‘encephalitis’?
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.
What are some causes of encephalitis?
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
What are some mimics of encephalitis?
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
What is ADEM?
-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
What is encephalitis lethargica?
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.
What is HSE?
-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
What is eastern equine encephalitis?
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.
