Test Catalog

Test Id : KPLA

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Karius Spectrum, Plasma

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Overview

Test Catalog

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

Rapid and minimally invasive detection of deep-seated and difficult-to-diagnose systemic infections throughout the body

 

Provide antimicrobial resistance detection for microbes known to utilize the antimicrobial resistance mechanism

Highlights

Karius Spectrum blood test leverages metagenomic sequencing of microbial cell-fee DNA to detect over 1000 fungi, bacteria, DNA viruses, and parasites using next-generation sequencing.(1) Absolute concentrations for each microbe are reported as molecules/100 nanoliters.

 

In addition to detecting over 1000 pathogens from blood, the Karius Spectrum test can detect common antimicrobial resistance (AMR) markers for 4 classes of antimicrobials across 18 bacterial pathogens (SCCmec, mecA, mecC, vanA, vanB, blaCTX-M and blaKPC).

 

For more information, see the following:

Karius Spectrum Liquid Biopsy for Infectious Diseases

In the Guidelines: Plasma Metagenomic Sequencing (MNGS) of Microbial Cell-Free DNA (mcfDNA)

 

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

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

Metagenomic Sequencing

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

Karius Spectrum, P

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

Karius

Karius Spectrum

Liquid Biopsy for Infectious Diseases

Plasma mcfDNA

Plasma Microbial Cell-Free DNA

Metagenomics

Metagenomic sequencing

Next-Generation Sequencing

Metagenomic Next-Generation Sequencing

NGS

mNGS

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

Specimen Type
Describes the specimen type validated for testing

Plasma

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

Collection Container/Tube:

Preferred: Plasma preparation tube (PPT)

Acceptable: Lavender top (K2 EDTA)

Submission Container/Tube:

Preferred: PPT

Acceptable: Sterile polypropylene tube

Specimen Volume: 1 mL Plasma

Collection Instructions :

1. Gently invert tube 8 to 10 times to mix whole blood.

2. Centrifuge specimen as follows:

 a. For PPT: Within 6 hours of collection, centrifuge at 1100 x g for 10 minutes.

 b. For K2 EDTA:

  i. Within 24 hours of collection, centrifuge at 1600 x g for 10 minutes. For tubes less than 4 mL, refer to tube manufacturer’s instructions for centrifugation speed and time.

  ii. Aliquot 1 mL of plasma into a sterile polypropylene tube, taking care not to disturb the buffy coat.

3. For complete instructions see Karius Spectrum Specimen Collection and Preparation Process.

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.

Plasma: 0.7 mL

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

Incomplete or improper plasma separation 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
Plasma Frozen (preferred) 180 days
Ambient 4 days

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

Rapid and minimally invasive detection of deep-seated and difficult-to-diagnose systemic infections throughout the body

 

Provide antimicrobial resistance detection for microbes known to utilize the antimicrobial resistance mechanism

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

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

Karius Spectrum is a blood test leveraging metagenomic sequencing of microbial cell-fee DNA to detect over 1000 bacteria, fungi, parasites, and DNA viruses associated with deep-seated and difficult-to-diagnose systemic infections. The Karius Spectrum test may assist clinicians in reducing low-yield, sequential or diagnostic tests requiring tissue or fluid collection, which can delay treatment for vulnerable hospitalized patients.

 

In addition, Karius Spectrum provides antimicrobial resistance detection when appropriate. This is designed to help healthcare professionals use targeted therapy to improve patient outcomes. Four classes of antimicrobial resistance are detected (methicillin-resistant Staphylococci [SCCmec, mecA, mecC], vancomycin-resistant Enterococci [vanA, vanB], carbapenem-resistant gram-positive bacteria [KPC], and extended spectrum beta-lactamase producing gram-negative bacteria [CTX-M]) for 18 bacterial pathogens.

 

For more information see Karius Spectrum In the Guidelines: Plasma Metagenomic Sequencing (MNGS) of Microbial Cell-Free DNA (MCFDNA).

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.

An interpretive report will be provided.

Interpretation
Provides information to assist in interpretation of the test results

A positive result indicates that microbial cell-fee DNA (mcfDNA) of one or more potentially pathogenic microorganisms was detected. The concentration of the mcfDNA detected will be provided in the report.

 

A negative result indicates absence of detectable mcfDNA from potentially pathogenic bacteria, fungi, parasites, and DNA viruses. A negative result does not rule the presence of a pathogen due to lack of a reference sequence in the database used or the presence of mcfDNA in quantities lower than the assay's limit of detection. Results should be interpreted in the clinical context of the patient.

 

This test detects antimicrobial resistance conferred by the following markers: SCCmec, mecA, mecC, vanA, vanB, CTX-M, or KPC. Evaluation for these markers will be performed when a microbe known to utilize the antimicrobial resistance mechanism is reported.

 

For more information see Understanding the Karius Spectrum Test Report.

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

The Karius Spectrum test does not detect RNA viruses.

 

Recent treatment with defibrotide sodium, an oligonucleotide drug derived from porcine tissue, may result in detectable microbial cell-free DNA from porcine-associated microbes and should be considered when interpreting results.

 

This test has been validated only for human plasma collected in EDTA anticoagulant.

 

Reliable results are dependent on adequate specimen collection, processing, transport, and storage procedures.

 

This test will report uncertain or unresolved species within the corresponding genus, eg, Aspergillus flavus/oryzae or Neisseria species.

 

The antimicrobial resistance marker may not always be linked with the microbe indicated.

 

The presence or absence of an antimicrobial resistance marker does not always correlate to the expected phenotype.

 

The assay analytical sensitivity is influenced by the depth of sequencing achieved. A minimum sequencing depth is required to pass quality control. Many batches achieve greater than this minimum sequencing depth resulting in enhanced sensitivity.

 

Concentration values for different microbes may not be comparable to each other.

 

To increase the clarity of the report as it relates to infections, microbes detected as frequently co-occurring are not reported when found together in one specimen. This may reduce the sensitivity to detect polymicrobial events such as mucosal membrane barrier disruptions, skin disruptions, gut injuries or aspiration pneumonia.

 

Microbes within a taxonomic family may not be reported when detected at less than 25% of the most abundant microbe within the corresponding taxonomic family.

 

Microbes within a taxonomic superkingdom are not reported when detected at less than 3% of the most abundant microbe within the superkingdom.

 

False-positive or false-negative results may occur for reasons including but not limited to sporadic contamination from specimen collection, reagent, and materials or hospital and laboratory environments, technical and biological factors.

 

The report of a microbe signifies the presence of its cell-free DNA in the patient's plasma specimen. It may or may not be the cause of an infection. Results should be interpreted within the context of clinical data, including medical history, physical findings, epidemiological factors, and other laboratory data.

Supportive Data

Metagenomic sequencing was clinically validated in the SEP-SEQ Study, which enrolled 350 patients with suspected sepsis in the Emergency Department at Stanford University Hospital. The study demonstrated high agreement with standard diagnostics, increased pathogen detection compared to blood cultures and other microbiological tests, and potentially faster identification of the etiology of sepsis than the standard diagnostic workup.(1)

 

For more information see the following:

Karius Spectrum Clinical Evidence Guide

Karius Spectrum Invasive Fungal Infection Clinical Evidence Guide

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

1. Blauwkamp TA, Thair S, Rosen MJ, et al. Analytical and clinical validation of a microbial cell-free DNA sequencing test for infectious disease. Nat Microbiol. 2019;4(4):663-674. doi:10.1038/s41564-018-0349-6

2. KC, Pfaller MA, eds. Manual of Clinical Microbiology. 12th ed. ASM Press; 2019

3. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases, 9th ed. Elsevier; 2019

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

Karius Spectrum utilizes metagenomic sequencing of microbial-cell free DNA (mcfDNA) in plasma. The daily lab workflow involves preparing reagents and setting up automation systems for processing blood samples. Quality control materials are added to plasma samples to monitor issues such as contamination, technical errors, or sample mix-ups. DNA sequencing is performed directly from plasma without needing to extract DNA first, using a process tailored to recover microbial DNA efficiently. Each batch of samples is prepared together and sequenced using high-throughput instruments. Sequencing results are automatically analyzed and checked against background signals in real time. To improve the accuracy of clinical results, advanced bioinformatics filters are used, which help distinguish between true infections and background microbes commonly found in healthy individuals or due to environmental contamination. The filters are based on large reference datasets and known microbial patterns. Sequencing reads are matched to a comprehensive microbial reference database, and results are filtered to ensure they meet quality standards. The clinical reportable range includes over 1000 bacteria, DNA viruses, fungi and parasites known to be associated with human infections.

 

For a listing of pathogens see https://kariusdx.com/our-solution/pathogens?product=spectrum.

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

Referral

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 through Saturday

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.

2 to 6 days

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

90 days

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

Karius Laboratory

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.

The Karius Spectrum test was developed and its performance characteristics determined by Karius. The Karius laboratory is certified under the Clinical Laboratory Improvement Amendments of 1988 (CLIA '88) and is accredited by the College of American Pathologists (CAP) to perform high-complexity clinical laboratory testing. This test has not been reviewed or cleared by the US Food and Drug Administration.

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.

0152U

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
KPLA Karius Spectrum, P Not Provided
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.
KPLA Karius Spectrum, P Not Provided

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

Test Update Resources

Change Type Effective Date
New Test 2025-12-09