Lennon, Vanda A.

ABSTRACTIntroductionThe clinical significance of striational antibodies (StrAbs) detected in the course of paraneoplastic antibody testing is unknown.MethodsWe compared all 203 striational antibody (StrAb)‐seropositive patients identified (2004–2005) during evaluation for paraneoplastic antibodies with age‐ and sex‐matched seronegative controls.ResultsThymoma and myasthenia gravis (MG) were significantly more common among cases (P<0.0001). Cancers more rarely detected after StrAb detection were adenocarcinoma in 5 patients and sarcoma in 3 patients. All patients who had a cancer identified after StrAb testing had a titer of ≥1:7680 or a coexisting muscle AChR‐binding antibody. Autoimmune disorders more commonly observed among cases (with any StrAb value) included: hypothyroidism; rheumatoid arthritis; and pernicious anemia (all P<0.05).ConclusionsStrAbs may serve as a diagnostic clue for an autoimmune diagnosis. There is a low likelihood of oncological significance in patients with StrAb titers <1:7680 without coexisting paraneoplastic Abs. Muscle Nerve, 2013

SummaryNeural‐specific autoantibodies have been documented and their diagnostic utility validated in diseases affecting the neuraxis from cerebral cortex to the somatic, autonomic, and enteric nervous system and skeletal muscle. These neurological disorders occur both idiopathically and in a paraneoplastic context. Molecular identification of the antigens has expedited development of confirmatory and high‐throughput tests for serum and cerebrospinal fluid, which permit early diagnosis and reveal the underlying molecular pathogenic mechanisms. The autoantibodies are classifiable on the basis of antigen location: intracellular (nuclear or cytoplasmic) or plasma membrane. Immunohistopathological studies of patients’ biopsied and autopsied tissues suggest that effector T cells mediate the autoimmune neurological disorders for which defining autoantibodies recognize intracellular antigens. Antigens within intact cells are inaccessible to circulating antibody, and the associated neurological deficits rarely improve with antibody‐depleting therapies. Tumoricidal therapies may arrest neurological progression, but symptom reversal is rare. In contrast, autoantibodies specific for plasma membrane antigens have pathogenic potential, and the associated neurological deficits are often amenable to antibody‐depleting immunotherapy, such as plasma exchange and anti‐B‐cell monoclonal antibody therapy. These reversible neurological disorders are frequently misdiagnosed as neurodegenerative. The focus of this review is the immunobiology, pathophysiology, and clinical spectrum of autoimmune neurological disorders accompanied by neural‐specific IgGs.