Ordering Recommendation

Aids in the diagnosis of neurodegenerative disease and limbic encephalitis. May be used to monitor treatment response in individuals who are antibody positive. The presence of IgLON5 antibodies may be associated with sleep disorders, bulbar symptoms, gait problems, cognitive dysfunction, movement disorders, or dysautonomia. IgLON5 autoimmune neurologic/neurodegenerative disorders may be paraneoplastic, but tumor type is variable.

New York DOH Approval Status

This test is New York state approved.

Specimen Required

Patient Preparation

Separate CSF.

Specimen Preparation

Transfer 0.5 mL CSF to an ARUP standard transport tube. (Min: 0.15 mL)

Storage/Transport Temperature


Unacceptable Conditions

Grossly hemolyzed or contaminated specimens.


Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 month (Three freeze/thaw cycles are acceptable)


Semiquantitative Cell-Based Indirect Fluorescent Antibody




1-8 days

Reference Interval

Less than 1:1

Interpretive Data

IgLON Family Member 5 (IgLON5) antibody is found in a subset of patients with autoimmune encephalitis or other autoimmune neurologic/neurodegenerative disorders and may occur with or without associated tumor. A negative test result does not rule out a diagnosis of an autoimmune neurologic disorder. Interpretation of any antineural antibody test requires clinical correlation.
This indirect fluorescent antibody assay utilizes IgLON5 transfected cell lines for detection and semiquantification of IgLON5 IgG antibody.

Compliance Category

Laboratory Developed Test (LDT)


If IgLON5 antibody IgG is positive, then IgLON5 antibody IgG titer will be added. Additional charges apply.

Hotline History


CPT Codes

86255; if reflexed, add 86256


Component Test Code* Component Chart Name LOINC
3006014 IgLON5 Ab IgG CBA-IFA Screen, CSF 96481-7
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.


  • autoimmune encephalitis
  • dementia
  • encephalopathy
  • IgLON 5
  • Limbic encephalitis
  • movement disorder
  • neurodegenerative disease
  • sleep disorder
IgLON Family Member 5 (IgLON5) Antibody, IgG by CBA-IFA With Reflex to Titer, CSF