Reference Values

Encephalitis Antibody Panel (CSF)

Lymphocytic Choriomeningitis (LCM) Virus Ab, IFA (CSF)

Reference Range:          IgG       <1:1

                                    IgM       <1:1

Interpretive Criteria:

                                    <1:1                  Antibody Not Detected

                                    >or= 1:1            Antibody Detected

Diagnosis of infections of the central nervous system can be accomplished by demonstrating the presence of intrathecally-produced specific antibody. However, interpreting results is complicated by low antibody levels found in CSF, passive transfer of antibody from blood and contamination via bloody taps.

This assay was developed and its performance characteristics determined by Focus Diagnostics. It has not been cleared or approved by the U.S. Food and Drug Administration. The FDA has determined that such clearance or approval is not necessary. Performance characteristics refer to the analytical performance of the test.

Measles (Rubeola) IgG and IgM Antibody Panel (CSF)

Reference Range:          IgG       <1:64

                                    IgM       <1:1

Diagnosis of infections of the central nervous system can be accomplished by demonstrating the presence of intrathecally-produced specific antibody. Interpreting results may be complicated by low antibody levels found in CSF, passive transfer of antibody from blood and contamination via bloody taps. The interpretation of CSF results must consider CSF-serum antibody ratios to the infectious agent.

This assay was developed and its performance characteristics determined by Focus Diagnostics. It has not been cleared or approved by the U.S. Food and Drug Administration. The FDA has determined that such clearance or approval is not necessary. Performance characteristics refer to the analytical performance of the test.

Mumps Antibody Panel, IFA (CSF)

Reference Range:          IgG       <1:8

                                    IgM       <1:1

Diagnosis of infections of the central nervous system can be accomplished by demonstrating the presence of intrathecally-produced specific antibody. Interpretation of results may be complicated by low antibody levels found in CSF, passive transfer of antibody from blood and contamination via bloody taps. The interpretation of CSF results must consider CSF-serum antibody ratios to the infectious agent.

This assay was developed and its performance characteristics determined by Focus Diagnostics. It has not been cleared or approved by the U.S. Food and Drug Administration. The FDA has determined that such clearance or approval is not necessary. Performance characteristics refer to the analytical performance of the test.

Varicella-Zoster Virus (VZV) Antibody (Total, IgM), ACIF/IFA, CSF

Reference Ranges:        VZV Total AB    <1:2

                                    VZV IgM           <1:1

Diagnosis of infections of the central nervous system can be accomplished by demonstrating the presence of intrathecally-produced specific antibody. Interpreting results may be complicated by low antibody levels found in CSF, passive transfer of antibody from blood and contamination via bloody taps. The interpretation of CSF results must consider CSF-serum antibody ratios to the infectious agent.

This assay was developed and its performance characteristics determined by Focus Diagnostics. It has not been cleared or approved by the U.S. Food and Drug Administration. The FDA has determined that such clearance or approval is not necessary. Performance characteristics refer to the analytical performance of the test.

West Nile Virus Antibodies (IgG, IgM), CSF

Reference Range:          IgG       <1.30

                                    IgM       <0.90

Interpretive Criteria:

            IgG:      <1.30                Antibody not detected

                        1.30 – 1.49        Equivocal

                        ≥1.50              Antibody detected

            IgM:      <0.90                Antibody not detected

                        0.90 – 1.10        Equivocal

                        >1.10                Antibody detected

West Nile Virus (WNV) IgM is usually detectable in CSF from WNV-infected patients with encephalitis or meningitis at the time of clinical presentation. Because IgM antibody does not readily cross the blood-brain barrier, IgM antibody in CSF strongly suggests acute central nervous system infection. WNV antibody results from CSF should be interpreted with caution. Possible complicating factors include low levels of antibody found in CSF, passive transfer of antibodies from blood and contamination via bloody spinal taps. Antibodies induced by other flavivirus infections (e.g. Dengue virus, St. Louis encephalitis virus) may show cross-reactivity with WNV.

Herpes Simplex Virus 1/2 (IgG) Type Specific Antibodies, CSF

Reference Range:          ≤ 1.00

Interpretive Criteria:

            ≤ 1.00        Antibody not detected

            >1.00                Antibody detected

Detection of HSV type-specific IgG in CSF may indicate central nervous system (CNS) infection by that HSV type. However, interpretation of results may be complicated by a number of factors, including low antibody levels found in CSF, passive transfer of antibody across the blood-brain barrier, and serum contamination of CSF during CSF collection. PCR detection of type-specific HSV DNA in CSF is the preferred method for identifying HSV CNS infections.

Herpes Simplex Virus 1/2 Antibody (IgM), IFA with Reflex to Titer, CSF

Reference Range:          Negative

The IFA procedure for measuring IgM antibodies to HSV 1 and HSV 2 detects both type-common and type-specific HSV antibodies. Thus, IgM reactivity to both HSV 1 and HSV 2 may represent cross-reactive HSV antibodies rather than exposure to both HSV 1 and HSV 2.

Diagnosis of central nervous system infections can be accomplished by demonstrating the presence of intrathecally-produced specific antibody. Interpreting results may be complicated by low antibody levels found in CSF, passive transfer of antibody from blood and contamination via bloody taps. The interpretation of CSF results must consider CSF-serum antibody ratios to the infectious agent.

This test was developed and its characteristics have been determined by Focus Diagnostics. Performance characteristics refer to the analytical performance of the test.