INDIVIDUAL TEST 750
Ri (Nova 1/ ANNA-2) Antibodies (IgG)
Indication
Suspicion of paraneoplastic syndrome
Sample material
Serum
- Minim. volume: 0,5 mL
CSF
- Minim. volume: 2,0 mL
Transport
Within Sweden
- room temperature
International
- cold
Method
Immunoblot/Indirect immunofluorescence (IIF)
According to Updated Diagnostic Criteria for Paraneoplastic Neurologic Syndromes, anti-neuronal antibodies should be detected by at least two independent methods to be reliable. At Wieslab IIF and immunoblot are used.
Reference interval
Serum
- Immunoblot: ≤5 negative
- Indirect Immunofluorescence: <1:10 negative
Likvor
- Immunoblot: negative
- Indirect immunofluorescence: negative
Result
Serum
- Immunoblot: results are reported as negative, borderline, or positive with an intensity value.
- Indirect immunofluorescence (IIF): results are reported as negative or positive. Positive results will be titrated.
CSF
- Immunoblot: results are reported as negative, borderline, or positive.
- Indirect immunofluorescence (IIF): results are reported as negative 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 with small-cell lung cancer. Neurological symptoms can precede cancer diagnosis by up to 5 years.
Antibodies against Ri are graded as High-risk antibodies with a frequency of >70% of underlying cancer and a positive result yields a 3-point PNS score, according to Updated Diagnostic Criteria for Paraneoplastic Neurologic Syndromes.
References
- Rosenfeld MR, Dalmau J. Neurol Clin. 2018. Paraneoplastic Neurologic Syndromes. PMID: 30072076
- Balint B et al. Brain. 2018. Movement disorders with neuronal antibodies: syndromic approach, genetic parallels and pathophysiology. PMID: 29053777
- Graus F et al. Neurol Neuroimmunol Neuroinflamm. 2021. Updated Diagnostic Criteria for Paraneoplastic Neurologic Syndromes. PMID: 34006622
- Garza M, Piquet AL. Front Neurol. 2021. Update in Autoimmune Movement Disorders: Newly Described Antigen Targets in Autoimmune and Paraneoplastic Cerebellar Ataxia. PMID: 34489848
Last updated: 2024-10-21
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ENSKILD ANALYS 750
Ri (Nova 1/ ANNA-2)-antikroppar (IgG)
Indikation
Misstanke om paraneoplastiskt syndrom
Provmaterial
Serum
- Minim. volym: 0,5 mL
Likvor
- Minim. volym: 2,0 mL
Transport
Inom Sverige
- rumstemperatur
Internationellt
- kylt
Metod
Immunoblot/Indirekt immunofluorescens (IIF)
Enligt Updated Diagnostic Criteria for Paraneoplastic Neurologic Syndromes ska anti-neuronala antikroppar detekteras med minst två oberoende metoder för att vara tillförlitligt. På Wieslab används IIF och immunoblot.
Referensintervall
Serum
- Immunoblot: ≤5 negativt
- Indirekt Immunofluorescens: <1:10 negativt
Likvor
- Immunoblot: negativt
- Indirekt immunofluorescens: negativt
Resultat
Serum
- Immunoblot: resultat anges som negativt, gränsvärde eller positivt med intensitetsvärde.
- Indirekt immunofluorescens: resultat anges som negativt eller positivt. Positivt resultat titreras.
Likvor
- Immunoblot: resultat anges som negativt, gränsvärde eller positivt.
- Indirekt immunofluorescens: resultat anges som negativt 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 cancerdiagnos 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
- Rosenfeld MR, Dalmau J. Neurol Clin. 2018. Paraneoplastic Neurologic Syndromes. PMID: 30072076
- Balint B et al. Brain. 2018. Movement disorders with neuronal antibodies: syndromic approach, genetic parallels and pathophysiology. PMID: 29053777
- Graus F et al. Neurol Neuroimmunol Neuroinflamm. 2021. Updated Diagnostic Criteria for Paraneoplastic Neurologic Syndromes. PMID: 34006622
- Garza M, Piquet AL. Front Neurol. 2021. Update in Autoimmune Movement Disorders: Newly Described Antigen Targets in Autoimmune and Paraneoplastic Cerebellar Ataxia. PMID: 34489848
Senast uppdaterat: 2024-10-21
Mer information
Detta är en ackrediterad analys.> Läs mer [.pdf]
Mer information om provtagning.
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