|
CSF IgG |
Serum IgG |
CSF Albumin |
Serum Albumin |
CSF IgG / CSF Alb |
IgG Index |
|
0.5 - 6.1 |
525 - 1765 |
13.4 - 23.7 |
3400 - 5000 |
0.04 - 0.28 |
0.30 - 0.70 |
|
Age |
Ratio |
|
17 - 30 |
1.7 - 5.7 |
|
31 - 40 |
1.8 - 6.8 |
|
41 - 50 |
2.0 - 7.2 |
|
51 - 60 |
2.1 - 8.9 |
|
>60 |
3.2 - 9.0 |
OLIGOCLONAL BANDS - ABSENT
All of the tests are within normal limits.The normal CSF albumin/serum albumin indicates normal permeability of the blood brain barrier. The normal IgG index suggests no increased IgG synthesis in the CNS. No oligoclonal bands are seen.
Normal index and oligoclonal bands
OLIGOCLONAL BANDS - PRESENT
The normal CSF albumin/serum albumin indicates normal permeability of the blood brain barrier. The normal IgG index suggests no increased IgG synthesis in the CNS. Oligoclonal bands reflecting synthesis of IgG of restricted heterogeneity are seen in the gamma region. These are most often seen in inflammatory or immune processes.
OLIGOCLONAL BANDS - FAINT
The normal CSF albumin/serum albumin indicates normal permeability of the blood brain barrier. The normal IgG index suggests no increased IgG synthesis in the CNS. Faint oligoclonal bands are seen in the gamma region. Based on previous studies, these bands are probably not clinically significant.
Elevated albumin ratio, normal index, and no bands
OLIGOCLONAL BANDS - ABSENT
The elevated CSF albumin/serum albumin indicates increased permeability of the blood brain barrier. This occurs most commonly in inflammatory or immune processes involving the CNS. The normal IgG index suggests no increased IgG synthesis in the CNS. However, increased permeability of the blood brain barrier can mask moderate increases in CNS IgG synthesis. No oligoclonal bands are seen in the gamma region.
Elevated albumin ratio, normal index, and bands
OLIGOCLONAL BANDS - PRESENT
The elevated CSF albumin/serum albumin indicates increased permeability of the blood brain barrier. This occurs most commonly in inflammatory or immune processes involving the CNS. The normal IgG index suggests no increased IgG synthesis in the CNS. However, increased permeability of the blood brain barrier can mask moderate increases in CNS IgG synthesis. Oligoclonal bands reflecting synthesis of IgG of restricted heterogeneity are seen in the gamma region. These are most often seen in inflammatory or immune processes.
Elevated albumin ratio, faint bands
OLIGOCLONAL BANDS - FAINT
The elevated CSF albumin/serum albumin ratio for person of this age indicates increased permeability of the blood brain barrier. This occurs most commonly in inflammatory or immune processes involving the CNS. The normal IgG index suggests no increased IgG synthesis in the CNS. However, increased permeability of the blood brain barrier can mask moderate increases in CNS IgG synthesis. Faint oligoclonal bands are seen in the gamma region. Based on previous studies, these bands are probably not clinically significant.
Elevated albumin ratio, elevated IgG index and faint bands
OLIGOCLONAL BANDS - ABSENT
The elevated CSF albumin/serum albumin ratio for person of this age indicates increased permeability of the blood brain barrier. The elevated IgG index indicates increased IgG synthesis in the CNS. This occurs most commonly in inflammatory or immune processes involving the CNS. Oligoclonal bands reflecting synthesis of IgG of restricted heterogeneity are seen in the gamma region. Gamma trace protein is present in the slow gamma region.
Normal IgG index and faint bands
OLIGOCLONAL BANDS - ABSENT
All of the tests are within normal limits. The normal CSF albumin/serum albumin indicates normal permeability of the blood brain barrier. The normal IgG index suggests no increased IgG synthesis in the CNS. Faint oligoclonal bands are seen in the gamma region. Based on previous studies, these bands are probably not clinically significant.
High index; no oligoclonal bands
OLIGOCLONAL BANDS - ABSENT
The normal CSF albumin/serum albumin indicates normal permeability of the blood brain barrier. The elevated IgG index indicates increased IgG synthesis in the CNS. This occurs most commonly in inflammatory or immune processes involving the CNS. No oligoclonal bands are seen in the gamma region.
High index and oligoclonal bands
OLIGOCLONAL BANDS - PRESENT * FAINT * PROMINENT
The normal CSF albumin/serum albumin indicates normal permeability of the blood brain barrier. The elevated IgG index indicates increased IgG synthesis in the CNS. This occurs most commonly in inflammatory or immune processes involving the CNS. Moderate oligoclonal bands reflecting synthesis of IgG of restricted heterogeneity are seen in the gamma region. These are most often seen in inflammatory or immune processes.
The levels of albumin and IgG in the CSF are within normal limits. The CSF index of normal immunoglobulin synthesis in the CNS and the CSF/serum albumin ratio for estimation of the integrity of the blood brain barrier could not be calculated because of the lack of a serum sample with the CNS.
Gamma trace protein is also present in the slow gamma region.
OLIGOCLONAL BANDS - ABSENT
An abnormal band is present in the slow gamma region of both serum and spinal fluid. This is consistent with a systemic paraprotein that has diffused into the CSF. Serum Protein electrophoresis and immunofixation is suggested to characterize the suspect paraprotein.
The elevated CSF albumin/serum albumin indicates increased permeability of the blood brain barrier. This occurs most commonly in inflammatory or immune processes involving the CNS. The normal IgG index suggests no increased IgG synthesis in the CNS. However, increased permeability of the blood brain barrier can mask moderate increases in CNS IgG synthesis.
No oligoclonal bands are seen in the gamma region.
TOP
Contaminated Sample
The repeat measurements of albumin and IgG in CSF provided similar values. The CSF albumin measures very low. This is an unusual condition that could result from dilution of the sample with saline or some other fluid before it arrived in the laboratory. This would invalidate the calculation of IgG index. However, the oligoclonal band pattern is definite.
**** Test for CSF in nasal or aural fluid: RESULT - POSITIVE
A distinct band of beta-2 migrating transferrin was identified by immunofixation of a concentrated nasal fluid sample.
Beta-1 transferrin is a serum protein containing four negatively charged sialic acid groups. In the central nervous system, neuraminidase causes desialation of part of the transferrin fraction. Loss of charged sialic acid groups changes the migration of this fraction on electrophoresis producing both beta-1 and beta-2 migrating bands. Beta-2 migrating transferrin has not been detected in other body fluids except aqueous and vitreous humor Consequently, detection of beta-2 transferrin in nasal or aural fluid is diagnostic for the presence of CSF.
IMMUNOFIXATION OF BETA-2 TRANSFERRIN FOR THE DETECTION OF CSF LEAKAGE
POSITIVE ASSAY:
Immunofixation of transferrin in this patient's nasal secretions has identified the beta-2 form of transferrin that is specific for CSF. These results are diagnostic for CSF rhinorrhea.
NEGATIVE ASSAY:
Immunofixation of transferrin in this patient's nasal secretions failed to identify the beta-2 form of transferrin that is specific for CSF. A very faint band corresponding to the serum form of transferrin (beta-1) was detected in the nasal secretions. These results do not support the diagnosis of CSF rhinorrhea. However, leakage of minute amounts of CSF cannot be ruled out.
Beta-2 transferrin is a desialylated form of the protein that is normally present in CSF, aqueous and vitreous humors. It is not normally found in nasal or aural fluids, saliva, tears or serum. The beta-2 form of transferrin can be resolved from the predominant serum form (beta-1) by immunofixation electrophoresis. Detection of beta-2 transferrin in nasal or aural secretions is diagnostic for the presence of CSF. A negative assay for beta-2 transferrin argues against the presence of CSF in the sample. However, due to limitations of sensitivity of the immunofixation method, a negative result cannot rule out leakage of minute amounts of CSF. If there is a strong clinical suspicion of CSF leakage, the concentration of larger samples of nasal or aural secretions followed by immunofixation for beta-2 transferrin may be warranted.
References:
1. Irjala, et al (1979). Arch Otolaryngol 105: 447-448.
2. Zaret, et al (1992). Clin Chem 38: 1909-1912.