Results That Matter

Interpreting Test Results

IGeneX provides physicians with information on how to interpret the results of each diagnostic test we offer. These test results, however, are not a diagnosis. Physicians should consider the test results from IGeneX in conjunction with a patient’s symptoms and medical history to determine the most accurate diagnosis.

Go here for a print-ready format of all Results Interpretations.

  • Babesiosis Test Interpretation

    Babesia microti IgG and IgM IFA

    The Babesia microti Indirect Immunofluorescent Antibody (IFA) test detects IgM and IgG antibodies to B. microti in human serum.

    Interpretation (titers)

    IgM < 20
    Negative. 20 may or may not indicate active infection.
    IgM 40
    Indicates active infection.
    IgG < 40
    Negative
    IgG 40 to < 160
    May or may not suggest active infection. In patients with previously high titers, such titers may indicate resolving infection.
    IgG 160
    Indicates active infection.

    Presence of both IgM and IgG together also indicates active infection.

    There is a low level of cross-reaction between B. microti and B. duncani IFA tests. In geographic regions where both species are present, we recommend that patient sera be tested by both B. microti and B. duncani IFA tests.

    A single negative IFA test does not rule out infection. Paired testing of acute and convalescent sera collected six to eight weeks apart is recommended for accurate diagnosis.

    Disclaimer: This test was developed and its performance characteristics determined by IGeneX, Inc. It has not been cleared or approved by the FDA. The FDA has determined that such approval is not necessary. The test is used for clinical purposes and should not be regarded as investigational or for research. IGeneX, Inc. is licensed by CMS and NYS to perform high complexity clinical laboratory testing.

    Babesia duncani IFA

    The Babesia duncani Indirect Immunofluorescent Antibody (IFA) test detects IgM and IgG antibodies to B. duncani in human serum.

    Interpretation (titers)

    IgM < 20
    Negative. 20 May or may not indicate active infection.
    IgM 40
    Indicates active infection.
    IgG < 40
    Negative
    IgG 40 to < 160
    May or may not suggest active infection. In patients with previously high titers, such titers may indicate resolving infection.
    IgG 160
    Indicates active infection.

    Presence of both IgM and IgG together also indicates active infection.

    There is a low level of cross-reaction between B. duncani and B. microti IFA tests. In geographic regions where both species are present, we recommend that patient sera be tested by both B. duncani and B. microti IFA tests.

    A single negative IFA test does not rule out infection. Paired testing of acute and convalescent sera collected six-to-eight weeks apart is recommended for accurate diagnosis.

    Disclaimer: This test was developed and its performance characteristics determined by IGeneX, Inc. It has not been cleared or approved by the FDA. The FDA has determined that such approval is not necessary. The test is used for clinical purposes and should not be regarded as investigational or for research. IGeneX, Inc. is licensed by CMS and NYS to perform high complexity clinical laboratory testing.

    Babesia FISH

    The Babesia Fluorescent In-Situ Hybridization (FISH) assay is a qualitative test that detects ribosomal RNA of Babesia directly in a blood smear. The Babesia FISH test provides a significant increase in sensitivity and specificity over standard Geimsa-stained smears for the presence of intraerythrocytic parasites (piroplasts) in RBCs. The parasites exist as ring and/or merozoite forms.

    Interpretation:

    A positive sample:
    must show fluorescing rings inside at least two RBCs.
    A negative sample:
    must show no fluorescence within RBCs.
    A single negative FISH test result does not exclude the possibility of Babesia infection.
    Results should be interpreted in conjunction with other laboratory and clinical findings.

    Disclaimer: This test was developed and its performance characteristics determined by IGeneX, Inc. It has not been cleared or approved by the FDA. The FDA has determined that such approval is not necessary. The test is used for clinical purposes and should not be regarded as investigational or for research. IGeneX, Inc. is licensed by CMS and NYS to perform high complexity clinical laboratory testing.

    Babesia microti/duncani PCR

    The Babesia microti/duncani Polymerase Chain Reaction (PCR) screen test detects Babesia-specific (B. microti and/or B. duncani) DNA in human specimen. Babesia ribosomal DNA (rDNA) fragments are hybrid-selected by probes, followed by PCR amplification of selected Babesia rDNA. PCR products are detected Babesia-specific probes in a dot-blot assay. The primers and probes used for the selection of Babesia rDNA fragments are designed from published small subunit ribosomal RNA sequences (NCBI: GI 1453221 for B. microti and GI 6272590 for B. duncani).

    Interpretation:

    Positive Babesia specific DNA detected.
    Negative Babesia specific DNA not detected.

    Disclaimer: This test was developed and its performance characteristics determined by IGeneX, Inc. It has not been cleared or approved by the FDA. The FDA has determined that such approval is not necessary. The test is used for clinical purposes and should not be regarded as investigational or for research. IGeneX, Inc. is licensed by CMS and NYS to perform high complexity clinical laboratory testing.

     

  • Bartonella Test Interpretation

    Bartonella IgXSpot Test

    The Bartonella IGXSpot is an Enzyme-Linked ImmunoSpot assay that detects human T cells reactive to Bartonella specific antigens in vitro. It is well documented that both humoral and cellular immune responses develop in Bartonella infection. The cellular immune response develops much earlier than humoral response in most patients infected with Bartonella. In some patients sero-conversion from cellular to humoral response does not occur or occurs much later in disease; and in some patients with chronic form of the disease, the humoral response is poor. Thus the Bartonella IGXSpot test is recommended for detection of very early and/or late Bartonella infection; and in seronegative patient’s whole blood samples.

    Interpretation:
    Positive: >3 CFU
    Negative: <2 CFU

    Limitation: For diagnostic purposes, the IGXSpot test results should be used in conjunction with clinical symptoms and other evidence available to the diagnosing physician. If the test result is negative, testing with another method is recommended. Depending on the stage of the disease patients can have either humoral or cellular immune response to infection. Thus, it is advisable to perform Bartonella species Western Blot IgM and IgG tests with IGXSpot test.

    Disclaimer: This test was developed and its performance characteristics determined by IGeneX, Inc. It has not been cleared or approved by the FDA. The FDA has determined that such approval is not necessary. The test is used for clinical purposes and should not be regarded as investigational or for research. IGeneX, Inc. is licensed by CMS and NYS to perform high complexity clinical laboratory testing.

    B. henselae IFA

    The Bartonella henselae indirect immunofluorescent antibody test is used to detect IgM and IgG antibodies to B. henselae in human serum.

    Interpretation (titers):

    IgM < 20
    Negative. 20 May or may not indicate active infection.
    IgM 40
    Indicates active infection.
    IgG < 40
    Negative
    IgG 40 to < 160
    May or may not suggest active infection. In patients with previously high titers, such titers may indicate resolving infection.
    IgG 160
    Indicates active infection.

    Presence of IgM and IgG together also indicates active infection.

    A single negative IFA test does not rule out infection. Paired testing of acute and convalescent sera collected six to eight weeks apart is recommended for accurate diagnosis.

    Disclaimer: This test was developed and its performance characteristics determined by IGeneX, Inc. It has not been cleared or approved by the FDA. The FDA has determined that such approval is not necessary. The test is used for clinical purposes and should not be regarded as investigational or for research. IGeneX, Inc. is licensed by CMS and NYS to perform high complexity clinical laboratory testing.

     

    B. henselae PCR

    Sample Type: whole blood and cerebral spinal fluid (CSF)

    The Bartonella henselae PCR test is an assay that detects B. henselae specific DNA in human specimen. B henselae rDNA fragments are hybrid- selected by probes, followed by PCR amplification of selected B. henselae rDNA. PCR products are detected with B. henselae specific probes in a dot blot assay. The primers and probes used for the selection of B. henselae rDNA fragments are designed from published small subunit ribosomal RNA sequences (NCBI GI:2828304).

    Interpretation:

    Positive: B. henselae rDNA detected.
    Negative: B. henselae rDNA not detected.

    Disclaimer: This test was developed and its performance characteristics determined by IGeneX, Inc. It has not been cleared or approved by the FDA. The FDA has determined that such approval is not necessary. The test is used for clinical purposes and should not be regarded as investigational or for research. IGeneX, Inc. is licensed by CMS and NYS to perform high complexity clinical laboratory testing.

    Bartonella FISH

    The Bartonella Fluorescent In Situ Hybridization (FISH) test detects bacteria of the Genus Bartonella including B. vinsonii, B. berkhoffii, B. henselae, and B. quintana in whole blood smears. Bartonella are rod shaped gram negative bacteria. The FISH test provides a significant increase in specificity over standard gram stain for the presence of Bartonella in whole blood smears.

    Interpretation:

    Positive: Fluorescing rod-shaped bodies detected in the smear.
    Negative: Fluorescing rod-shaped bodies not detected in the smear.

    Disclaimer: This test was developed and its performance characteristics determined by IGeneX, Inc. It has not been cleared or approved by the FDA. The FDA has determined that such approval is not necessary. The test is used for clinical purposes and should not be regarded as investigational or for research. IGeneX, Inc. is licensed by CMS and NYS to perform high complexity clinical laboratory testing.

  • Ehrlichia & Anaplasma Test Interpretation

    E. chaffeensis (HME) IFA

    HME (Human Monocytic Ehrlichiosis) immunofluorescent antibody test detects IgM and IgG antibodies to Ehrlichia chaffeensis, the causative agent of HME in human serum.

    Interpretation (titers)

    IgM < 20
    Negative. 20 May or may not indicate active infection.
    IgM 40
    Indicates active infection.
    IgG < 40
    Negative
    IgG 40 to < 160
    May or may not suggest active infection. In patients with previously high titers, such titers may indicate resolving infection.
    IgG 160
    Indicates active infection.

    Presence of both IgM and IgG together also indicates active infection.

    Cross-reactions can occur among the Rickettsiaceae, including Rickettsia, Ehrlichia and Anaplasma. A single negative IFA test does not rule out infection. Paired testing of acute and convalescent sera collected six to eight weeks apart is recommended for accurate diagnosis.

     

    Disclaimer: This test was developed and its performance characteristics determined by IGeneX, Inc. It has not been cleared or approved by the FDA. The FDA has determined that such approval is not necessary. The test is used for clinical purposes and should not be regarded as investigational or for research. IGeneX, Inc. is licensed by CMS and NYS to perform high complexity clinical laboratory testing.

    A. phagocytophilum (HGA) IFA

    The HGA (Human Granulocytic Anaplasmosis) immunofluorescent antibody test is used to detect IgM and IgG antibodies to Anaplasma phagocytophilum, the causative agent of HGA in human serum.

    Interpretation (titers):

    IgM < 20
    Negative. 20 May or may not indicate active infection.
    IgM 40
    Indicates active infection.
    IgG < 40
    Negative
    IgG 40 to < 160
    May or may not suggest active infection. In patients with previously high titers, such titers may indicate resolving infection.
    IgG 160
    Indicates active infection.

    Presence of both IgM and IgG together also indicates active infection. Cross-reactions can occur among the Rickettsiaceae, including Rickettsia, Ehrlichia and Anaplasm. A single negative IFA test does not rule out infection. Paired testing of acute and convalescent sera collected six to eight weeks apart is recommended for accurate diagnosis.

    Disclaimer: This test was developed and its performance characteristics determined by IGeneX, Inc. It has not been cleared or approved by the FDA. The FDA has determined that such approval is not necessary. The test is used for clinical purposes and should not be regarded as investigational or for research. IGeneX, Inc. is licensed by CMS and NYS to perform high complexity clinical laboratory testing.

    Ehrlichia chaffeensis (HME) PCR

    The HME (Human Monocytic Ehrlichiosis) PCR test detects Erhlichia chaffeensis rDNA fragments in the patient samples. The E. chaffeensis rDNA fragments are hybrid selected by probes, followed by PCR amplification of the selected fragments using Ehrlichia specific primers. E. chaffeensis specific PCR products are then detected with probes in a dot-blot assay.

    Interpretation:

    Positive: E. chaffeensis rDNA detected.
    Negative: E. chaffeensis rDNA not detected.

     

    Disclaimer: This test was developed and its performance characteristics determined by IGeneX, Inc. It has not been cleared or approved by the FDA. The FDA has determined that such approval is not necessary. The test is used for clinical purposes and should not be regarded as investigational or for research. IGeneX, Inc. is licensed by CMS and NYS to perform high complexity clinical laboratory testing.

    Anaplasma phagocytophilum (HGA) PCR

    Sample Type: whole blood

    The HGA (Human Granulocytic Anaplasmosis) PCR test detects Anaplasma phagocytophilum rDNA fragments in the patient specimens. The A. phagocytophilum rDNA fragments are hybrid-selected by probes, followed by PCR amplification of the selected fragments using Anaplasma specific primers. A. phagocytophilum specific PCR products are then detected with probes in a dot-blot assay.

    Interpretation:

    Positive: A. phagocytophilum rDNA detected
    Negative: A. phyagocytophilum rDNA not detected.

    Disclaimer: This test was developed and its performance characteristics determined by IGeneX, Inc. It has not been cleared or approved by the FDA. The FDA has determined that such approval is not necessary. The test is used for clinical purposes and should not be regarded as investigational or for research. IGeneX, Inc. is licensed by CMS and NYS to perform high complexity clinical laboratory testing.

  • Lyme Disease Test Interpretation

    Lyme IgG ImmunoBlot

    The Lyme ImmunoBlot Test is a qualitative assay that detects B. burgdorferi strains and species IgG antibodies in human serum. Recombinant B. burgdorferi species antigens are sprayed at specific positions onto a nitrocellulose membrane and cut into strips. These strips are used to detect B. burgdorferi specific antibodies in patient serum.

    IGeneX Criteria:

    Based on internal validation studies, IGeneX established the following criteria:

    Positive: If two or more of the following bands are present: 23, 31, 34, 39, 41 and 93 kDa.

    Negative: Any profile that does not meet positive criteria

    CDC/NYS Criteria:

    Positive: If 5 of the following 10 bands are present: 18, 23, 28, 30, 39, and 41, 45, 58, 66 and 93kDa.
    Negative: Any profile that does not meet the positive criteria.

    Limitation: Positive ImmunoBlot result with 31 and/or 34kDa may be present after Lyme vaccination in uninfected persons. Viral antibodies cross react with the 93kDa antigen. A positive result suggests exposure to B. burgdorferi. For diagnostic purposes, immunoblot test results should be used in conjunction with clinical symptoms and other evidence available to the diagnosing physician. If only one of the following bands: 23, 31, 34, 39 and 93kDa is present or if one or more of these bands are indeterminate on the ImmunoBlot, testing with another method or retesting after 6-8 weeks is recommended.

    Disclaimer: This test was developed and its performance characteristics determined by IGeneX, Inc. It has not been cleared or approved by the FDA. The FDA has determined that such approval is not necessary. The test is used for clinical purposes and should not be regarded as investigational or for research. IGeneX, Inc. is licensed by CMS and NYS to perform high complexity clinical laboratory testing.

    Lyme IgM ImmunoBlot

    The Lyme ImmunoBlot IgM Test is a qualitative assay that detects B. burgdorferi strains and species IgM antibodies in human serum. Recombinant B. burgdorferi species antigens are sprayed at specific positions onto a nitrocellulose membrane and cut into strips. These strips are used to detect B. burgdorferi specific antibodies in patient serum.

    IGeneX Criteria:

    Based on internal validation studies, IGeneX established the following criteria:

    Positive: If two or more of the following 5 bands are present: 23, 31, 34, 39 and 41kDa.

    Negative: Any profile that does not meet positive criteria

    CDC/NYS Criteria:

    Positive: If 2 of the following 3 bands are present: 23, 39, and 41kDa.
    Negative: Any profile that does not meet the positive criteria.

    Limitation: Positive ImmunoBlot result with 31 and/or 34kDa may be present after Lyme vaccination in uninfected persons. Viral antibodies cross react with the 93kDa antigen. A positive result suggests exposure to B. burgdorferi. For diagnostic purposes, immunoblot test results should be used in conjunction with clinical symptoms and other evidence available to the diagnosing physician. If only one of the following bands: 23, 31, 39kDa is present or if one or more of these bands are indeterminate on the ImmunoBlot, testing with another method or retesting after 6-8 weeks is recommended.

    Disclaimer: This test was developed and its performance characteristics determined by IGeneX, Inc. It has not been cleared or approved by the FDA. The FDA has determined that such approval is not necessary. The test is used for clinical purposes and should not be regarded as investigational or for research. IGeneX, Inc. is licensed by CMS and NYS to perform high complexity clinical laboratory testing.

    Lyme IgXSpot

    The Lyme IgXSpot is an Enzyme-Linked ImmunoSpot assay that detects human T cells reactive to B. burgdorferi specific antigens in vitro. It is well documented that both humoral and cellular immune responses develop in Borrelia infection. The cellular immune response develops much earlier than humoral response in most patients infected with B. burgdorferi. In some patients sero-conversion from cellular to humoral response does not occur or occurs much later in disease; and in some patients with chronic form of the disease, the humoral response is poor. Thus the Lyme IgXSpot test is recommended for detection of very early and/or late B. burgdorferi infection; and in seronegative patient’s whole blood samples.

    Interpretation:

    Positive: > or = 3 SFU
    Negative: < or = 2 SFU

     

    Limitation: For diagnostic purposes, the IgXSpot test results should be used in conjunction with clinical symptoms and other evidence available to the diagnosing physician. If the test result is negative, testing with another method is recommended. Depending on the stage of the disease patients can have either humoral or cellular immune response to infection. Thus, it is advisable to perform Lyme ImmunoBlot IgM and IgG tests with IgXSpot test.

    Disclaimer: This test was developed and its performance characteristics determined by IGeneX, Inc. It has not been cleared or approved by the FDA. The FDA has determined that such approval is not necessary. The test is used for clinical purposes and should not be regarded as investigational or for research. IGeneX, Inc. is licensed by CMS and NYS to perform high complexity clinical laboratory testing.

     

    LYME IgM Serology

    This test detects presence of specific IgM antibodies to B. burgdorferi. Positive results with clinical history may indicate early stage Lyme disease. IgM may also be present in Stage II or Stage III Lyme disease

    Lyme Index Value (LIV) Interpretation

    1.2
    Positive. Confirmatory assays recommended.
    0.8 and < 1.2
    Equivocal. Retesting in two to four weeks recommended.
    <0.8
    Negative. Indicates IgM antibodies to B. burgdorferi not detected.

    If Lyme disease is suspected in a patient exhibiting a negative result, an IgG and IgM Western Blot should be performed.

    Lyme IgM Western Blot

    IGeneX Criteria:
    Based on internal validation studies, IGeneX established the following criteria:
    Positive If two or more of the following bands are present:
    23-25, 31, 34, 39, 41 and 83-93 kDa.
    Exception:
    Negative: If only bands 41 kDa and 83-93 kDa are present.
    Indeterminate If:
    only bands 31 and 41kDa OR only bands 31 and 83-93kDa are present.

    Note: There are two Borrelia antigens present at 31kDa position on the Western blot strip. One (Osp A) is a very specific marker of Lyme disease whereas the second antigen is a house keeping gene that can also present in some viruses and bacteria, including other spirochetes. Therefore, when there a positive signal at position 31 kDa band, there is 50% chance (based on our internal review of patient data collected over years) that the positive signal is due to presence of Lyme specific antibody in patient serum. Thus, the following confirmation test of an Indeterminate Western Blot IgM result is recommended: Test # 488 31kDa Epitope Test IgM.

    Negative If:
    only bands 41 and 83-93kDa from the positive criteria are present OR if test result does not meet either positive or indeterminate criteria.

    CDC/NYS Criteria:
    The Lyme IgM Western Blot is considered positive if:
    2 of the following 3 bands are present: 23-25, 39, and 41kDa.

    Limitation: Positive Lyme Western blot result with 31 and/or 34kDa may be present after Lyme vaccination in uninfected persons. Viral antibodies cross react with the 93kDa antigen. A positive result suggests exposure to B. burgdorferi. For diagnostic purposes, Western blot test results should be used in conjunction with clinical symptoms and other evidence available to the diagnosing physician. If only one of the following bands: 23, 31, 34, 39 and 93kDa is present or if one or more of these bands are indeterminate on the ImmunoBlot, testing with another method or retesting after 6-8 weeks is recommended.

    Disclaimer: This test was developed and its performance characteristics determined by IGeneX, Inc. It has not been cleared or approved by the FDA. The FDA has determined that such approval is not necessary. The test is used for clinical purposes and should not be regarded as investigational or for research. IGeneX, Inc. is licensed by CMS and NYS to perform high complexity clinical laboratory testing.

    Lyme IgG Western Blot

    IGeneX Criteria:
    Based on internal validation studies, IGeneX established the following criteria:
    Positive If:
    two or more of the following bands are present: 23-25, 31, 34, 39, 41 and 83-93 kDa.
    Exception – Indeterminate:
    If only bands 31 and 41kDa are present.

    Note: There are two Borrelia antigens present at 31kDa position on the Western blot strip. One (Osp A) is a very specific marker of Lyme disease whereas the second antigen is a house keeping gene that can also present in some viruses and bacteria, including other spirochetes. It is also present in some viruses and other spirochetes. Therefore, when there a positive signal at position 31 kDa band, there is 50% chance (based on our internal review of patient data collected over years) that the positive signal is due to presence of Lyme specific antibody in patient serum. Thus, the following confirmation test of an Indeterminate Western Blot IgG result is recommended: Test # 489 31 kDa Epitope Test IgG.

    Negative If:
    test result does not meet either positive or indeterminate criteria.

    CDC/NYS Criteria:

    The Lyme IgG Western Blot is considered positive if 5 of the following 10 bands are present: 18, 23-25, 28, 30, 39, and 41, 45, 58, 66 and 83-93kDa.

    Limitation: Positive Lyme Western blot result with 31 and/or 34kDa may be present after Lyme vaccination in uninfected persons. Viral antibodies cross react with the 93kDa antigen. A positive result suggests exposure to B. burgdorferi. For diagnostic purposes, Western blot test results should be used in conjunction with clinical symptoms and other evidence available to the diagnosing physician. If only one of the following bands: 23, 31, 34, 39 and 93kDa is present or if one or more of these bands are indeterminate on the ImmunoBlot, testing with another method or retesting after 6-8 weeks is recommended.

    Disclaimer: This test was developed and its performance characteristics determined by IGeneX, Inc. It has not been cleared or approved by the FDA. The FDA has determined that such approval is not necessary. The test is used for clinical purposes and should not be regarded as investigational or for research. IGeneX, Inc. is licensed by CMS and NYS to perform high complexity clinical laboratory testing.

     

    IgM 31 kDa Epitope

    This test determines whether the band present at position 31 kDa on the IGeneX Lyme IgM Western Blot is specific for B. burgdorferi. Serum from the patient is tested against a Western Blot strip with fixed B burgdorferi specific recombinant antigen fragments.

    Interpretation

    IGeneX interpretation is based on internal validation studies performed on well-defined Lyme patients:
    67
    Positive
    161
    Negative
    The assay sensitivity is 95% and specificity is 98%.
    Limitations: Positive results for band 31kDa may be present after vaccination in uninfected persons. The Lyme 31kDa Epitope test specificity was >97% in a viral positive panel.
    Positive: Antibodies specific for B. burgdorferi detected.
    Negative: Antibodies specific for B. burgdorferi not detected.

    Disclaimer: This test was developed and its performance characteristics determined by IGeneX, Inc. It has not been cleared or approved by the FDA. The FDA has determined that such approval is not necessary. The test is used for clinical purposes and should not be regarded as investigational or for research. IGeneX, Inc. is licensed by CMS and NYS to perform high complexity clinical laboratory testing.

    Lyme Multiplex PCR

    Sample type: Serum, whole blood, urine, pooled urines, CSF and miscellaneous clinical samples.

    The Lyme Multiplex PCR test is a 3 step amplified nucleic acid assay that detects Borrelia burgdorferi specific DNA sequences from Osp A plasmid and flagellin genomic genes, in clinical specimens. The gene fragments are first selected with specific probes. Then the DNA is amplified using specific primers. Lastly, the amplified products are detected by hybridization to specific probes in a dot-blot assay.

    The test also detects DNA to other Borrelia: B. afzeli, B. andersonii, B. garinii and B. mayoni.

    Interpretation:

    Genomic Positive:
    B. burgdorferi DNA detected.
    Negative:
    B. burgdorferi DNA not detected.
    Plasmid Positive:
    B. burgdorferi DNA detected.
    Negative:
    B. burgdorferi DNA not detected.
    Sample is considered positive if either genomic or plasmid is positive.

    Disclaimer: This test was developed and its performance characteristics determined by IGeneX, Inc. It has not been cleared or approved by the FDA. The FDA has determined that such approval is not necessary. The test is used for clinical purposes and should not be regarded as investigational or for research. IGeneX, Inc. is licensed by CMS and NYS to perform high complexity clinical laboratory testing.

    Limitation: The diagnostic value of a negative serum/urine/blood PCR result for Borrelia species is questionable because the number of organisms in serum/urine/blood is often low or nonexistent in patients with Lyme disease.

    Lyme Dot-blot Assay

    Sample types: urine, CSF.

    The Lyme Dot-blot Assay (LDA) is a qualitative immunoassay for the direct detection of B. burgdorferi specific antigens in urine that react specifically to the following B. burgdorferi antibodies: 23-25kDa (OspC), 31kDa, 39kDa and 93kDa.

    Interpretation:

     Positive
    B. burgdorferi antigens detected
    Negative
    B. burgdorferi antigens not detected

    Cross-reactions can occur with other microorganisms present in urine samples. Therefore, clinicians should use caution in the interpretation of a positive result when no other Lyme diagnostic test result is positive.

     

    Disclaimer: This test was developed and its performance characteristics determined by IGeneX, Inc. It has not been cleared or approved by the FDA. The FDA has determined that such approval is not necessary. The test is used for clinical purposes and should not be regarded as investigational or for research. IGeneX, Inc. is licensed by CMS and NYS to perform high complexity clinical laboratory testing.

     

  • Relapsing Fever Test Interpretation

    TBRF and B. burgdorferi sensu lato real-time PCR

    Sample type: Serum, Whole blood, CSF, Urine, Pooled Urines and miscellaneous clinical samples

    The TBRF Borrelia and B. burgdorferi sensu lato real-time PCR test detects Relapsing Fever Borrelia DNA (including B. hermsii) and B. burgdorferi sensu lato DNA. It further speciates RF Borrelia to subgroup that includes B. turcatae, B. miyamotoi, B. parkeri, B. coriaceae, and B. recurrentis. DNA is extracted from clinical samples. The extracted DNA is amplified by real-time PCR with Borrelia specific DNA primers; RF Borrelia DNA (if present) is detected by RF Borrelia genus probe, speciated to RF Borrelia subgroup by RF Borrelia species probe; and B. burgdorferi sensu lato DNA (if present) is detected by the B. burgdorferi specific probe simultaneously. The primers and probes used for the selection of RF Borrelia and B. burgdorferi sensu lato DNA fragments are designed from published small subunit ribosomal RNA sequences of RF Borrelia group and B. burgdorferi sensu lato group. For diagnostic purposes PCR results should be used in conjunction with other data available to the physician.

    Interpretation:

    RF Borrelia Genus (detects RF Borrelia species including B. hermsii, B. turicatae, B. miyamotoi, B. parkeri, B. coriaceae, B. turcica, and B. recurrentis)
    Positive:
    RF Borrelia DNA was detected.
    Negative:
    RF Borrelia DNA was not detected in the sample analyzed.

    RF Borrelia Subgroup Species (detects B. turicatae, B. miyamotoi, B. parkeri, B. coriaceae and B.recurrentis)
    Positive:
    RF Borrelia species DNA was detected.
    Negative:
    RF Borrelia species DNA was not detected in the sample analyzed.

    B. burgdorferi sensu lato (detects B. burgdorferi sensu stricto, B. afzelii, B. garinii, B. californiensis, B. mayonii, B. spielmanii and B. valaisiana)
    Positive:
    B. burgdorferi sensu lato DNA was detected.
    Negative:
    B. burgdorferi sensu lato DNA was not detected in the sample analyzed.

    Borrelia (detects B. chiliensis, B. sinica and B. japonica)
    Positive:
    Borrelia DNA was detected.
    Negative:
    Borrelia DNA was not detected in the sample.

    Limitation: An inhibition study was performed on about 2000 clinical samples that included fresh whole blood, fresh serum, frozen urine and frozen CSF samples, according to NYS guidelines. It is clear that for all sample types tested, inhibition is well controlled and only occurred in less than 1% of samples. Therefore, no inhibition control is included in the assay.

    Disclaimer: The diagnostic value of a negative serum/urine/blood PCR result for Borrelia species is questionable because the number of organisms in serum/urine/blood is often low or nonexistent in patients with Lyme disease.

    Disclaimer: This test was developed and its performance characteristics determined by IGeneX, Inc. It has not been cleared or approved by the FDA. The FDA has determined that such approval is not necessary. The test is used for clinical purposes and should not be regarded as investigational or for research. IGeneX, Inc. is licensed by CMS and NYS to perform high complexity clinical laboratory testing.

    TBRF IgG ImmunoBlot

    The TBRF IgG ImmunoBlot Test is a qualitative immunoblot assay that detects IgG antibodies in human serum to the following TBRF associated Borrelia species: B. miyamotoi, B. hermsii, B. turicatae and B. coriaceae. Recombinant TBRF Borrelia antigens are sprayed at specific positions onto nitrocellulose membrane and cut into strips. These strips are used to detect TBRF Borrelia specific antibodies in patient serum.

    Interpretation:

    Positive:
    If two TBRF Borrelia specific bands are present.
    Indeterminate:
    If one TBRF Borrelia specific bands is present.
    Negative:
    Any profile that does not meet the positive or indeterminate criteria.

    Limitations: A positive result suggests exposure to TBRF Borrelia. For diagnostic purposes, immunoblot test results should be used in conjunction with clinical symptoms and other evidence available to the diagnosing physician. If the test result is indeterminate, testing with another method or retesting in 6-8 weeks is recommended.

    Disclaimer: This test was developed and its performance characteristics determined by IGeneX, Inc. It has not been cleared or approved by the FDA. The FDA has determined that such approval is not necessary. The test is used for clinical purposes and should not be regarded as investigational or for research. IGeneX, Inc. is licensed by CMS and NYS to perform high complexity clinical laboratory testing.

    TBRF IgM ImmunoBlot

    The TBRF IgM ImmunoBlot Test is a qualitative immunoblot assay that detects IgM antibodies in human serum to the following TBRF associated Borrelia species: B. miyamotoi, B. hermsii, B. turicatae and B. coriaceae. Recombinant TBRF Borrelia antigens are sprayed at specific positions onto nitrocellulose membrane and cut into strips. These strips are used to detect TBRF Borrelia specific antibodies in patient serum.

    Interpretation:

    Positive:
    If two TBRF Borrelia specific bands are present.
    Indeterminate:
    If one TBRF Borrelia specific bands is present.
    Negative:
    Any profile that does not meet the positive or indeterminate criteria.
    Limitations: A positive result suggests exposure to TBRF Borrelia. For diagnostic purposes, immunoblot test results should be used in conjunction with clinical symptoms and other evidence available to the diagnosing physician. If the test result is indeterminate, testing with another method or retesting in 6-8 weeks is recommended.

     

    Disclaimer: This test was developed and its performance characteristics determined by IGeneX, Inc. It has not been cleared or approved by the FDA. The FDA has determined that such approval is not necessary. The test is used for clinical purposes and should not be regarded as investigational or for research. IGeneX, Inc. is licensed by CMS and NYS to perform high complexity clinical laboratory testing.

  • Rickettsia Test Interpretations

    Rickettsia IFA

    The Rickettsia indirect immunofluorescent antibody test detects IgG antibodies to Rickettsia species in human serum. The species include Rickettsia rickettsii, causative agent of Rocky Mountain Spotted Fever and Ri. typhi, causative agent of Murine typhus respectively.

    Interpretation (titers):

    Spotted Fever Group or Typhus Fever Group
    IgG < 40
    Negative
    40 to < 160
    May or may not suggest active infection. In patients with previously high titers, such titers may indicate resolving infection.
    160
    Suggests active infection.

     

    Cross-reactions can occur among the Rickettsiaceae, including Rickettsia, Ehrlichia and Anaplasma. A single negative IFA test does not rule out infection. Paired testing of acute and convalescent sera collected six to eight weeks apart is recommended for accurate diagnosis.

    Disclaimer: This test was developed and its performance characteristics determined by IGeneX, Inc. It has not been cleared or approved by the FDA. The FDA has determined that such approval is not necessary. The test is used for clinical purposes and should not be regarded as investigational or for research. IGeneX, Inc. is licensed by CMS and NYS to perform high complexity clinical laboratory testing.

    Rickettsia PCR

    Sample Type: whole blood and cerebral spinal fluid (CSF)

    The Rickettsia PCR test detects Rickettsia species specific DNA in clinical samples. Rickettsia 17kDa antigen gene fragments are hybrid selected by probes, followed by PCR amplification of the selected DNA fragment. PCR products are detected with Rickettsia specific probes: Rickettsia rickettsii and Rickettsia felis/typhi in dot blot assays. The primers and probes used for the selection of Rickettsia gene fragment encoding the 17kDa antigen DNA fragments are designed from published sequences (NCBI: GI:30844225) (Anderson et al 1988 J Bacteriol 170:4493-4500); Tzianabos et al J Clin Microbiol 1989:2866-2868).

    Interpretation:

    Positive:
    Rickettsia specific DNA detected.
    Negative:
    Rickettsia specific DNA not detected.

    Disclaimer: This test was developed and its performance characteristics determined by IGeneX, Inc. It has not been cleared or approved by the FDA. The FDA has determined that such approval is not necessary. The test is used for clinical purposes and should not be regarded as investigational or for research. IGeneX, Inc. is licensed by CMS and NYS to perform high complexity clinical laboratory testing.