Screening for antibodies against the Ri antigen is used to investigate patients with possible paraneoplastic syndrome.
Antibodies against the Ri antigen (Nova 1 or ANNA-2 antibodies or specific anti-neuronal nuclear antibodies 2) are rarer than antibodies against the Hu antigen. Still, they can occur in paraneoplastic sensory-cerebral ataxia or paraneoplastic encephalomyelitis. The presence of these antibodies is closely linked to small-cell lung cancer. Neurological symptoms can precede the diagnosis of cancer up to five years earlier.
See also: Anti-Neuronal Antibodies
