Test Catalog

Test Id : LEPDT

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Leptospira, IgM, Serum

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Overview

Test Catalog

Useful For
Suggests clinical disorders or settings where the test may be helpful

Aiding in the diagnosis of leptospirosis

 

This test is not useful for establishing cure or response to therapy.

Highlights

This test is intended to be used as an aid for the diagnosis of acute or recent leptospirosis due to infection with Leptospira species.

 

This is a qualitative immunodot test for detection of IgM-class antibodies to Leptospira species.

 

A negative result by this assay does not exclude the possibility of leptospirosis, and all results must be correlated with clinical presentation and exposure history.

Method Name
A short description of the method used to perform the test

Enzyme-Linked Immunoassay Dot (Immunodot)

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.

Yes

Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

Leptospira, IgM, S

Aliases
Lists additional common names for a test, as an aid in searching

L. biflexa

Leptospirosis

Specimen Type
Describes the specimen type validated for testing

Serum

Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Supplies: Sarstedt Aliquot Tube, 5 mL (T914)

Collection Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 0.3 mL

Collection Instructions: Centrifuge and aliquot serum into plastic vial.

Additional Information: If acute and convalescent specimens are being obtained to determine seroconversion, they should be collected 2 or more weeks apart.

Forms

If not ordering electronically, complete, print, and send Infectious Disease Serology Test Request (T916) with the specimen.

Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the testing laboratory. The minimum volume is sufficient for one attempt at testing.

0.1 mL

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

Gross hemolysis Reject
Gross lipemia Reject

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 30 days
Frozen 30 days

Useful For
Suggests clinical disorders or settings where the test may be helpful

Aiding in the diagnosis of leptospirosis

 

This test is not useful for establishing cure or response to therapy.

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Leptospirosis is a zoonotic disease of worldwide prevalence, though the majority of infections occur in warm, tropical climates. Wild mammals, typically rodents, are the primary, natural reservoir for disease-causing strains of Leptospira; however, domestic animals (eg, dogs) also represent a major source of human infection. Leptospira are gram-negative spirochetes with at least 20 different species in the genus. Of these, at least 9 species are considered disease-causing, including the most common agent of leptospirosis, Leptospira interrogans.

 

Transmission occurs through indirect human contact (eg, via mucous membranes or abraded skin) with water, food, or soil contaminated with animal urine containing the Leptospira spirochetes. Following infection, the incubation period can range from 3 to 30 days, depending on the inoculum dose and immune status of the individual.

 

The clinical manifestations of leptospirosis can vary, ranging from a mild, flu-like illness (eg, headache, malaise, fever, arthralgia, fatigue) to fulminant disease with severe liver and kidney involvement. The latter manifestation was previously referred to as Weil disease. Leptospira organisms may be found in the blood at the onset of disease and can persist for approximately 1 week. Subsequently, spirochetes may be found in the urine and can persist for 2 to 3 months; however, shedding may be intermittent, and the number of organisms present may be low.

 

While Leptospira can be grown in culture, this is a fastidious organism that requires immediate transport to the laboratory. Additionally, detectable growth requires prolonged incubation (1-6 weeks), limiting the utility of culture for acute diagnosis. For this reason, serologic detection for antibodies to Leptospira remains the method of choice for rapid diagnosis. IgM-class antibodies to this spirochete are detectable by day 6 of illness and remain detectable for 2 to 3 months following symptom onset.

Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

Negative

Interpretation
Provides information to assist in interpretation of the test results

Positive:

IgM antibodies to Leptospira species detected, suggesting recent infection. Antibody presence alone cannot be used to definitively diagnose acute infection, as antibodies from a prior exposure or infection may remain detectable for a prolonged period.

 

Borderline:

Result should be interpreted with caution. Additional testing of a second, convalescent specimen is recommended. If the specimen remains borderline reactive, a second serological method should be considered if leptospirosis infection is still suspected.

 

Negative:

No IgM antibodies to Leptospira detected. Since antibodies may not be present or may be present at undetectable levels during early disease, repeat testing of a convalescent sample collected in 2 to 3 weeks is recommended.

Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

The temporal IgM immune response can vary among patients. Therefore, a single negative result by this assay should not be used to exclude diagnosis, especially in patients with symptoms suggestive of leptospirosis who have an appropriate exposure history.

 

This test does not distinguish between acute or past infection. Clinical correlation is required. Patients may remain seropositive for months to possibly years following resolution of disease; therefore, this test cannot be used to establish cure or response to therapy.

Supportive Data

Accuracy:

A total of 40 previously characterized serum samples tested by the Focus Diagnostics, Inc. Leptospirosis Indirect Hemagglutination Assay (IHA) (30 were positive and 10 were negative) were evaluated by the GenBio Leptospira IgM ImmunDOT assay. A summary of the results is provided in Table.

 

Table. Comparison of the GenBio and Focus Diagnostics Leptospira assays

 

Focus IHA pos

Focus IHA neg

ImmunoDOT pos

30

0

ImmunoDOT neg

0

10

 

Positive Agreement: 100% (30/30); 95% CI 86.5%-100%

Negative Agreement: 100% (10/10); 95% CI 67.9%-100%

Overall Agreement: 100% (40/40); 95% CI 89.5%-100%

Clinical Reference
Recommendations for in-depth reading of a clinical nature

1. Centers for Disease Control and Prevention, National Center for Emerging and Zoonotic Infectious Diseases (NCEZID), Division of High-Consequence Pathogens and Pathology (DHCPP): Leptospriosis. Reviewed June 24, 2024. Accessed September 5, 2024. Available at www.cdc.gov/leptospirosis/

2. Costa F, Hagan JE, Calcagno J, et al. Global morbidity and mortality of leptospirosis: a systemic review. PLoS Negl Trop Dis. 2015;9(9):e0003898. doi:10.1371/journal.pntd.0003898

Method Description
Describes how the test is performed and provides a method-specific reference

The GenBio IgM ImmunoDOT Leptosirosis test utilizes an enzyme-linked immunoassay dot technique for the detection of IgM antibodies. Leptospira biflexa, serovar Patoc 1 strain antigens are dispensed as discrete dots onto a solid membrane. After adding the test specimen to a reaction cuvette, an assay strip is inserted, allowing patient antibodies reactive with the test antigens to bind to the strip's solid support member. Alkaline phosphatase conjugated goat antihuman IgM antibodies are allowed to react with bound patient antibodies. Finally, the strip is transferred to an enzyme substrate reagent, which reacts with bound alkaline phosphatase to produce an easily seen, distinct spot.(Package insert: ImmunoDOT Leptospira IgM. GenBio; 06/20/2022)

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information

No

Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Monday, Thursday

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

Same day/1 to 5 days

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

14 days

Performing Laboratory Location
Indicates the location of the laboratory that performs the test

Rochester

Fees
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.

  • Authorized users can sign in to Test Prices for detailed fee information.
  • Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
  • Prospective clients should contact their account representative. For assistance, contact Customer Service.

Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.

This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.

86720

LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.

Test Id Test Order Name Order LOINC Value
LEPDT Leptospira, IgM, S 23201-7
Result Id Test Result Name Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
65183 Leptospira, IgM, S 23201-7

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports