DIAGNOSTIC TEST 750

Ri (Nova 1/ ANNA-2) Antibodies (IgG)

Diagnostic test for antibodies against Ri. For suspicion of paraneoplastic syndrome.

swedac

Accredited. View certificate [.pdf]

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

Included in these panels

Need pricing information?

Get a quote

How to order

This test is available worldwide for hospitals, clinics, and physicians.

  1. Print and complete the request form

    Download the request form. Clearly state the name and phone number of the referring hospital, clinic, or physician.

  2. Prepare your samples

    Serum: At least 0.5 mL serum (plain serum tubes without additives).
    CSF: At least 2 mL CSF (polypropylene tubes).

  3. Send samples and request form

    Within Sweden
    Samples can be sent at room temperature to:
    Envelopes and smaller boxes:
    Wieslab AB, Box 50117, 20211 Malmö, Sweden

    Larger boxes and frozen samples:
    Wieslab AB, Lundavägen 151, 21224 Malmö, Sweden

    International
    Send samples cold to:
    Wieslab AB, Lundavägen 151, 21224 Malmö, Sweden

Read our sampling instructions for more information

Last updated: 2025-08-18