Laboratory Test Guide

Leptospira Serology (Sendout)

General Information

Lab Name

Leptospira Serology

Lab Code

LEPTS

Epic Name

LEPTOSPIRA, SEROLOGY

External Test Id

LEPDT

Description

Useful For: Aiding in the diagnosis of leptospirosis.

Test Information:

This is 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.
Acute and convalescent specimens obtained to determine seroconversion should be collected 2 or more weeks apart.

Synonyms

L. biflexa, LEPDT, Leptospira IgM, Leptospirosis

Components

Code	Name
RLEPTM	Leptospira Antibody, IgM

Interpretation

Method

Enzyme-Linked Immunoassay Dot (Immunodot)

Reference Range

See individual components

Ref. Range Notes

Reference Values: Negative

Interpretation:

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 of time.
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.

Interferences and Limitations

Cautions:

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.

Guidelines

Washington DOH Notifiable Conditions

Ordering & Collection

Specimen Type

Blood

Collection

Collect 3 mL blood in a RED TOP tube or GOLD SST

Handling Instructions

Outside Laboratories: Centrifuge sample and transfer serum to a separate plastic vial. Refrigerate serum.

Stability: Refrigerated (preferred): 30 days; Frozen: 30 days; Ambient: Unacceptable.

Reject Due To: Gross hemolysis, gross lipemia.

Quantity

requested: 0.5 mL serum
minimum: 0.1 mL serum

Processing

Centrifuge sample and transfer serum to a separate plastic vial. Refrigerate serum.

Sendouts:

Order Mayo Test: LEPDT.
Interfaced: Yes.