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Immunology & Serology

High-Sensitivity CRP (hs-CRP)

High-Sensitivity CRP (hs-CRP) is a Immunology & Serology laboratory test reference in the LabPedia Medical Laboratory Library. Low-range CRP immunoassay used primarily for cardiovascular risk stratification; not a substitute for standard CRP in acute infection workups.

Also known ashsCRP; High-sensitivity C-reactive protein

Overview

hs-CRP is a CRP assay optimized for precise measurement at low concentrations used in atherosclerotic risk pathways.

Clinical Importance

Cardiovascular risk assessment as an adjunct when guideline pathways include hs-CRP

Research and selected preventive cardiology protocols

Specimen Requirements

  • Specimen: serum (preferred for most serology/autoimmune immunoassays) or plasma when the method is validated
  • Tube: gold/SST (serum separator) or red-top serum; follow method-specific plasma acceptability
  • Handling: allow SST to clot fully; centrifuge and separate promptly; avoid repeated freeze–thaw
  • Storage: refrigerate short-term; freeze aliquots for delayed testing per manufacturer stability
  • Stability: analyte- and kit-specific; do not exceed validated time/temperature limits

Analytical Method

High-sensitivity immunoturbidimetric or immunoassay methods quantify CRP at low mg/L levels with tighter precision requirements than standard CRP assays.

Instruments Used

Automated analyzers

  • Roche Cobas immunoassay systems
  • Abbott Alinity / Architect immunoassay systems
  • Siemens Healthineers Atellica / ADVIA Centaur immunoassay systems
  • Beckman Coulter Access / DxI immunoassay systems
  • bioMérieux VIDAS / BioFire immunoassays (selected analytes)
  • Ortho Clinical Diagnostics Vitros immunoassay systems
  • DiaSorin LIAISON immunoassay systems
  • Phadia / Thermo Fisher ImmunoCAP allergy systems
  • Manual ELISA, CLIA, and immunofluorescence platforms

Manual methods

  • Manual ELISA, agglutination, and immunofluorescence methods in selected settings

Reference Values

Assay cutoffs, units, and reference intervals are method- and manufacturer-specific. Always interpret against the performing laboratory report (CLSI EP28-A3c for quantitative intervals where applicable). Serologic patterns require clinical correlation and current guideline algorithms (WHO/CDC/society guidance as adopted locally).

Cardiovascular risk categories are commonly discussed around <1, 1–3, and >3 mg/L in some guidelines; use the method and guideline adopted locally; these are risk strata, not universal 'normal' intervals.

Interpretation

Common Causes of Increased Results

  • Higher hs-CRP within the low-range assay may indicate higher residual inflammatory cardiovascular risk when clinically applied

Common Causes of Decreased Results

  • Lower hs-CRP within validated strata; interpret only with full clinical risk assessment

Clinical Significance

  • Selected ASCVD risk adjunct testing

Factors Affecting Results

Pre-analytical

  • Hemolysis, lipemia, or icterus (assay-dependent interference)
  • Wrong tube type or incomplete clotting of SST
  • Repeated freeze–thaw of serum aliquots
  • Testing too early or too late relative to infection/vaccination timing for serology
  • Acute infection/inflammation invalidates cardiovascular hs-CRP interpretation

Analytical

  • Calibration/QC failure; reagent lot shifts
  • Hook effect / antigen excess on selected immunoassays
  • Heterophile antibodies, rheumatoid factor, or biotin interference (assay-dependent)

Post-analytical

  • Using hs-CRP cutoffs for acute infection decisions

Advantages and Limitations

Advantages

  • Precision at low concentrations

Limitations

  • Not for diagnosing acute infection
  • Confounded by any concurrent inflammatory process

Clinical Pearls

If the patient is febrile, do not call the cardiology hs-CRP; acute-phase CRP owns that visit.

Related Laboratory Tests

References

Authoritative textbooks, guidelines, and reviews supporting this laboratory test reference. Verify reference intervals, critical limits, and method details against institutional protocols and current guideline editions.

Textbooks

  • McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods (verify current edition). Chapters on clinical immunology and serology.
  • Rifai N, Horvath AR, Wittwer CT, eds. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics (verify current edition). Immunoassay and protein chapters.

CLSI and Professional Guidelines

  • Centers for Disease Control and Prevention. Laboratory testing recommendations for infectious disease serology and related algorithms (verify current CDC guidance for the pathogen).
  • Clinical and Laboratory Standards Institute. Defining, Establishing, and Verifying Reference Intervals in the Clinical Laboratory. CLSI document EP28-A3c (verify current edition).
  • Clinical and Laboratory Standards Institute. Immunoassay and related method evaluation documents (e.g., EP05, EP06, EP07, EP17; verify current editions relevant to the assay).
  • College of American Pathologists. Accreditation and proficiency testing expectations for immunology/serology (verify current CAP checklist requirements).
  • International Federation of Clinical Chemistry and Laboratory Medicine (IFCC). Recommendations relevant to protein and immunoassay measurands (verify current IFCC documents).

WHO Publications

  • World Health Organization. Laboratory and diagnostic guidance for serologic and immunologic testing (verify current WHO publication for the analyte/assay).

Frequently Asked Questions

Common questions about using this High-Sensitivity CRP (hs-CRP) laboratory test Medical Laboratory Library reference in Medical Laboratory Science education.

What is the High-Sensitivity CRP (hs-CRP) laboratory test reference used for?

This Medical Laboratory Library page summarizes the clinical importance of High-Sensitivity CRP (hs-CRP). Review the Clinical Importance section for why the test is ordered in laboratory medicine practice.

Where can I find High-Sensitivity CRP (hs-CRP) specimen requirements?

See the Specimen Requirements section on this page for specimen information related to High-Sensitivity CRP (hs-CRP). Confirm collection details against your laboratory protocol.

Where are High-Sensitivity CRP (hs-CRP) reference values listed?

See the Reference Values section on this Laboratory Library page. Reference ranges can vary by method and population, so verify intervals with your laboratory.

How do I interpret High-Sensitivity CRP (hs-CRP) results?

Use the Interpretation section for laboratory interpretation framing, including increased and decreased result patterns when provided. Do not treat educational text as a patient-specific diagnosis.

What analytical method is used for High-Sensitivity CRP (hs-CRP)?

See the Analytical Method section for principle and method notes. Method details may differ by instrument and institutional SOP.

Are related laboratory tests linked from High-Sensitivity CRP (hs-CRP)?

Yes. The Related Laboratory Tests section lists connected references for continued lookup in the Medical Laboratory Library.

How can I continue learning after reading High-Sensitivity CRP (hs-CRP)?

Use Continue learning links on this page for related Academy lessons, medical laboratory quizzes, or laboratory case studies when available for this Immunology & Serology topic.

What are the clinical pearls for High-Sensitivity CRP (hs-CRP)?

See the Clinical Pearls section for concise laboratory practice notes associated with High-Sensitivity CRP (hs-CRP). Apply pearls alongside institutional protocols.

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