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HelpTest Code LAB9040 Lyme Central Nervous System Infection IgG, Antibody Index, Spinal Fluid
Additional Codes
LNBAI
Specimen Required
Only orderable as part of a profile. For more information see LNBAB / Lyme Central Nervous System Infection IgG with Antibody Index Reflex, Serum and Spinal Fluid.
Specimen Type: Spinal fluid
Container/Tube: Sterile vial
Specimen Volume: 1.2 mL
Collection Instructions:
1. A spinal fluid (CSF) sample of 1.2 mL needs to be collected within 24 hours of the serum specimen, preferably at the same time.
2. Label vial as spinal fluid or CSF.
3. CSF aliquot should be from the second, third, or fourth CSF vial collected during the lumbar puncture.
Do not submit CSF from the first vial due to the possibility of blood contamination, which will cause specimen rejection.
4. Band specimens together.
Specimen Type: Serum
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume:Â 1.2 mL
Collection Instructions:
1. A serum sample of 1.2 mL needs to be collected within 24 hours of the spinal fluid specimen, preferably at the same time.
2. Centrifuge and aliquot serum into a plastic vial.
3. Label as serum.
4. Band specimens together.
Secondary ID
63249Useful For
Providing antibody index information to aid in the diagnosis of neuroinvasive Lyme disease or neuroborreliosis due to Borrelia species associated with Lyme disease (eg, Borrelia burgdorferi, Borrelia garinii, Borrelia afzelli)
Method Name
Only orderable as part of a profile. For more information see LNBAB / Lyme Central Nervous System Infection IgG with Antibody Index Reflex, Serum and Spinal Fluid.
Enzyme-Linked Immunosorbent Assay (ELISA)
Specimen Type
CSFSpecimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| CSF | Refrigerated (preferred) | 11 days | |
| Frozen | 35 days |
On-campus collections: Tube to 99 or deliver to University Extension Hospital Room EH318
Off-campus collections:
Specimen to be stored/transported Refrigerated
Reject Due To
| Gross hemolysis | Reject |
| Gross lipemia | Reject |
| CSF contaminated with blood | Reject |
Reference Values
Only orderable as part of a profile. For more information see LNBAB / Lyme Central Nervous System Infection IgG with Antibody Index Reflex, Serum and Spinal Fluid.
0.6-1.2
Interpretation
Negative (Lyme CNS antibody index [AI] 0.6 to <1.3): Results indicate lack of intrathecal antibody synthesis to Lyme disease associated Borrelia species. This suggests the absence of neuroinvasive Lyme disease. The initial screen reactive result may be due to anti-Borrelia species antibodies present in the cerebrospinal fluid (CSF) due to increased permeability of the blood-brain barrier or transient introduction during lumbar puncture.
Equivocal (Lyme CNS AI 1.3 to 1.5): Low level of intrathecal antibody synthesis to Lyme disease associated Borrelia species detected. Results should be correlated with exposure history and clinical presentation to establish a diagnosis of neuroinvasive Lyme disease.
Positive (Lyme CNS AI >1.5): Results indicate the presence of intrathecal antibody synthesis to Lyme disease associated Borrelia species, suggesting neuroinvasive Lyme disease. Results should be correlated with exposure history and clinical presentation to establish the diagnosis.
Invalid (Lyme CNS AI <0.6): Result is due to abnormally elevated total IgG levels in CSF. This may be due to passive diffusion through the blood-brain barrier or contamination of the CSF with blood during a traumatic lumbar puncture. Repeat testing may be considered
Method Description
The test uses microtiter strips with break-off reagent wells coated with a mix of Bb sl antigens (whole antigen extracts of Borrelia burgdorferi sensu stricto, Borrelia afzelii, Borrelia garinii and recombinant VlsE of B burgdorferi sensu stricto). In the first reaction step, diluted patient samples are incubated in the wells. In the case of positive samples, Borrelia-specific IgG antibodies will bind to the antigens. To detect the bound antibodies, a second incubation is carried out using an enzyme-labelled antihuman IgG (enzyme conjugate), followed by a third incubation using chromogen/substrate, which catalyzes a color reaction that is then measured for optical density (OD) using spectrophotometry. The obtained OD values of the paired patient serum and cerebrospinal fluid (CSF) samples are compared against a 6-level calibration curve to quantitatively determine the relative anti-Borrelia IgG antibody titers.(Unpublished Mayo method)
The quantitative test results obtained on paired serum and CSF specimens using the Borrelia IgG enzyme-linked immunosorbent assay are expressed as relative units (U/mL) and must be used along with the total IgG and albumin levels in the patient's paired serum and CSF samples to calculate the anti-Borrelia antibody index (AI), which determines the absence or presence of intrathecal anti-Borrelia IgG antibody synthesis. Total IgG and albumin testing on serum and CSF is performed using the Siemens BN II nephelometric testing system.(Instruction manual: Siemens Nephelometer II Operations. Siemens V 2.3, 2008; Addendum to the Instruction Manual 2.3, 08/2017)
To detect an infection of the central nervous system, it is necessary to differentiate between intrathecally produced antibodies and antibodies passed from blood into the CSF. The AI is the value of intrathecal pathogen-specific antibody production. This AI value represents the portion of pathogen-specific antibodies in total IgG of CSF and the portion of pathogen-specific antibodies in total IgG of serum. The patient's AI is calculated using the Reiber and Lange method.(Reiber H, Lange P: Quantification of virus-specific antibodies in cerebrospinal fluid and serum: sensitive and specific detection of antibody synthesis in brain. Clin Chem. 1991;37(7):1153-1160)
Day(s) Performed
Monday, Wednesday, Friday
Report Available
Same day/1 to 4 daysSpecimen Retention Time
14 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
86618 x 2
82040
82042
82784 x 2
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| LNBAI | Lyme CNS Infection IgG, Ab Index | 92812-7 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| LNB3 | Lyme CNS IgG Ab Index Value | 92811-9 |
| LNB4 | Lyme CNS IgG Ab Index Interp | 69048-7 |
Specimen Minimum Volume
See Specimen Required