Treponema pallidum DNA detection by NAAT

General Information

Lab Name

Treponema Pallidum DNA detection by NAAT

Lab Code

TPLDNA

Epic Ordering

Treponema pallidum DNA detection by NAAT

Description

Detection of Treponema pallidum DNA.

This test detects Treponema pallidum, the etiologic agent of syphilis and endemic treponematoses (e.g., yaws and pinta). It can be ordered as a primary diagnostic when syphilis is suspected and is also available reflexively when Bacterial DNA Detection by PCR (BCTDNA) suggests the presence of T. pallidum below the reporting threshold.

Please note that this assay does NOT distinguish subspecies of T. pallidum.

For more information on this test, to download a requisition form, and for a list of acceptable and unacceptable specimens, please refer to: Molecular Diagnosis Microbiology Section Website

Synonyms

23S LAMP, 23S PCR, chancre, darkfield microscopy, FTA-ABS, meningovascular, neurosyphilis, RPR, spirochete, Syphilis, tabes dorsalis, TP-PA, TPPA, Treponema, Treponema pallidum, treponeme, VDRL

Components

Code	Name
TP23RS	T pallidum NAAT: Detection, 23S rDNA
TPLID	T pallidum NAAT: Identification
TPLSI	T pallidum NAAT: Specimen Description
TPLSPI	T pallidum NAAT: External Identifier
TPLSR	T pallidum NAAT: Special Requests
TPLSC	T pallidum NAAT: Specimen Comments
TPLNAE	T pallidum NAAT: Specimen DNA Extraction
TPLREV	T pallidum NAAT: Pathologist Review
TPLME	T pallidum NAAT: Method Note

Interpretation

Method

DNA extraction, nucleic acid purification, Loop Mediated Isothermal Amplification

Reference Range

See individual components

Guidelines

Washington DOH Notifiable Conditions

Ordering & Collection

Specimen Type

Tissue (Fresh frozen or paraffin-embedded), Fluid (see Acceptable Specimens for details), Whole blood (EDTA-anticoagulated whole blood is an acceptable validated specimen type but requires director approval due to logistical & specimen batching considerations)

Collection

Acceptable specimens are listed below. Please see this page for complete specimen collection and handling instructions.

Specimens should be collected into a DNA free container labeled with at least two identifiers.

Acceptable Specimens

Fresh frozen tissue
Fresh frozen fluid: any body fluid is acceptable if it is not listed under Unacceptable Specimens. See common examples below.
Formalin Fixed Paraffin-embedded tissues (FFPE, PET): blocks, scrolls, and unstained slides are acceptable
eSwabs and UTM (universal transport media)
Whole blood, including cord blood, in a lavender/purple top EDTA tube
- Note: Director approval is required for submission of blood samples due to logistical & specimen batching considerations.

Common acceptable body fluid examples: cerebrospinal fluid, pleural fluid, pericardial fluid, urine, bronchial lavage, joint fluid, bone marrow, vitreous fluid, etc.

Additional Acceptable Specimens

Sputum

Unacceptable Specimens

Serum, plasma, stool
No citrated or heparinized solutions
No SPS (Sodium Polyanethole Sulfonate) e.g. Wampole Isolator Tubes
Tissues floating in formalin
Swab/fluid collected in tube containing agar

Handling Instructions

Fresh frozen tissue/fluid specimens should be submitted and maintained on dry ice.

Formalin Fixed Paraffin-embedded tissues (FFPE, PET) can be sent ambient or with ice packs during warmer summer months to prevent melting.

Whole blood should be frozen at -80C; please submit/transport specimens on dry ice.

Optimal Quantity:

Fresh Tissue: 0.3-1.0 cm^3
Fluid: 0.2-1 mL
Formalin Fixed Paraffin-embedded Tissue (FFPE/PET): blocks are preferred and will be sent back to client upon completion of testing
Scrolls/unstained slides: cross-sectional area >1cm^2 send 10 sections of 10µm thickness, if <1cm^2 send 20 sections if available
Whole Blood: at least 1mL of whole blood in a lavender/purple top EDTA tube. 1.5mL or more is requested.

Please note: We do not need a separate specimen aliquot for each test ordered. Only a single specimen aliquot or block of optimal quantity is necessary for performing multiple tests. If multiple aliquots or blocks of optimal quantity are sent, up to 2 will be pooled.

Quantity

requested: See Optimal Quantity above
minimum: Specimens below optimal quantity are acceptable for testing, however, diagnostic yield is generally proportional to specimen size.

Processing

Processing: UWMC/HMC – store and send specimen refrigerated and freeze specimens at -20°C (Note: -80C for whole blood) upon arrival in UW-ML Microbiology. If specimen storage and transport will exceed 8 hours, freeze at -20°C (-80C for whole blood).

Freeze specimens at -20°C upon arrival (Note: freeze at -80C for whole blood).

Outside Laboratories: Freeze tissue & body fluid specimens in sterile containers at -20°C. Freeze whole blood at -80C. Transport all specimens on dry ice.

Performance

LIS Dept Code

Micro Molecular Diag (MMD)

Performing Location(s)

UW-MT	Microbiology, Molecular Diagnostics 206-520-4600 Clinical Lab, Room # NW177, University of Washington Medical Center, 1959 NE Pacific street, Seattle, WA 98195

Frequency

Fresh frozen tissues/fluids result in 2-3 business days after receipt of specimen. Formalin Fixed Paraffin-embedded tissues result in 3-4 business days after receipt of specimen. Whole blood is batched and currently performed 1 – 2 times per week.

Available STAT?

Billing & Coding

CPT codes: 87798
LOINC: 41163-7
Interfaced Order Code: UOW4596