Method Immunoblot and indirect immunofluorescence (IIF).
According to guidelines, anti-neuronal antibodies should be detected by at least two independent methods. At Wieslab, IIF and immunoblot are used. According to European guidelines, a positive result should be obtained with both methods to be reliable.
Result Serum: The result is reported as negative, borderline or positive with a IIF titer and blot intensity.
CSF: The result is reported as negative, borderline or positive.
Interpretation Antibodies against Ri are also called Nova 1 or ANNA-2 (anti-neuron-specific cell nuclear antibodies), and occur less often than antibodies against Hu, but can be seen in paraneoplastic sensory neuronopathy, cerebellar ataxia and/or paraneoplastic encephalomyelitis. Prevalence is strongly associated to small cell lung cancer. Neurological symptoms can precede cancer diagnosis by up to 5 year.
Antibodies against Ri are graded as High-risk antibodies with frequency of >70% of underlying cancer and a positive result yield 3 points PNS score, according to Updated Diagnostic Criteria for Paraneoplastic Neurologic Syndromes.
References
Lancaster E, Martinez-Hernandez E, Dalmau J. Encephalitis and antibodies to synaptic and neuronal cell surface proteins. Neurology. 2011 Jul 12;77(2):179-89. PMID: 21747075
Balint B, Vincent A, Meinck HM, Irani SR, Bhatia KP. Movement disorders with neuronal antibodies: syndromic approach, genetic parallels and pathophysiology. Brain. 2018 Jan 1;141(1):13-36. PMID: 29053777
Graus F, et al. Updated Diagnostic Criteria for Paraneoplastic Neurologic Syndromes. Neurol Neuroimmunol Neuroinflamm. 2021 May 18;8(4):e1014. PMID: 34006622
Can't find what you're looking for? We are here to help
ENSKILD ANALYS 750
Ri (Nova 1 / ANNA-2) -antikroppar
Indikation Misstanke om paraneoplastiska syndrom
Metod Immunoblot samt indirekt immunofluorescens (IIF).
Enligt riktlinjer ska anti-neuronala antikroppar detekteras med minst två oberoende metoder. På Wieslab används IIF och immunoblot. Enligt europeiska riktlinjer ska positivt resultat uppnås med båda metoderna för att vara tillförlitligt.
Svar Serum: Resultatet anges som negativt, gränsvärde eller positivt med IIF titer och blot intensitet.
Likvor: Resultatet anges som negativt, gränsvärde eller positivt.
Tolkning Antikroppar mot Ri kallas också Nova 1 eller ANNA-2 (anti-neuronspecifika cell nukleära antikroppar) och är ovanligare än antikroppar mot Hu, men kan ses vid paraneoplastisk sensorisk neuronopati, cerebellar ataxi och/eller paraneoplastisk encephalomyelit. Förekomst är starkt kopplat till småcellig lungcancer. Neurologiska symtom kan föregå cancerdiagnosen med upp till 5 år.
Antikropparna riktade mot Ri bedöms vara High-risk antibodies med en förekomst på >70% för en underliggande cancer och positivitet ger 3 poäng i PNS score enligt Updated Diagnostic Criteria for Paraneoplastic Neurologic Syndromes.
Referenser
Lancaster E, Martinez-Hernandez E, Dalmau J. Encephalitis and antibodies to synaptic and neuronal cell surface proteins. Neurology. 2011 Jul 12;77(2):179-89. PMID: 21747075
Balint B, Vincent A, Meinck HM, Irani SR, Bhatia KP. Movement disorders with neuronal antibodies: syndromic approach, genetic parallels and pathophysiology. Brain. 2018 Jan 1;141(1):13-36. PMID: 29053777
Graus F, et al. Updated Diagnostic Criteria for Paraneoplastic Neurologic Syndromes. Neurol Neuroimmunol Neuroinflamm. 2021 May 18;8(4):e1014. PMID: 34006622