Search our extensive Laboratory Test Directory to find test codes, ordering recommendations, specimen stability information, Test Fact Sheets, and more.
Recommendations when to order or not order the test. May include related or preferred tests.
Calculate glomerular filtration rate in patients for whom serum creatinine may be misleading, such as the very obese, elderly, or malnourished patients.
New York DOH Approval Status
Indicates test has been approved by the New York State Department of Health.
This test is New York state approved.
Specimen Required
Patient PreparationInstructions patient must follow before/during specimen collection.
CollectSpecimen type to collect. May include collection media, tubes, kits, etc.
Serum Separator Tube (SST), Plasma Separator Tube (PST), or Green (Lithium or Sodium Heparin).
Specimen PreparationInstructions for specimen prep before/after collection and prior to transport.
Allow specimen to clot completely at room temperature. Separate from cells ASAP or within 2 hours of collection. Transfer 1 mL serum or plasma to an ARUP Standard Transport Tube. (Min: 0.4 mL)
Storage/Transport TemperaturePreferred temperatures for storage prior to and during shipping to ARUP. See Stability for additional info.
Refrigerated.
Unacceptable ConditionsCommon conditions under which a specimen will be rejected.
Grossly hemolyzed specimens.
RemarksAdditional specimen collection, transport, or test submission information.
StabilityAcceptable times/temperatures for specimens. Times include storage and transport time to ARUP.
After separation from cells: Ambient: Unacceptable; Refrigerated: 1 week; Frozen: 3 months
Methodology
Process(es) used to perform the test.
Quantitative Nephelometry
Performed
Days of the week the test is performed.
Sun-Sat
Reported
Expected turnaround time for a result, beginning when ARUP has received the specimen.
Within 24 hours
Reference Interval
Normal range/expected value(s) for a specific disease state. May also include abnormal ranges.
Test Number
Components
Reference Interval
Cystatin C
0.5 - 1.2 mg/L
Interpretive Data
May include disease information, patient result explanation, recommendations, or details of testing.
eGFR by Cystatin C Calculation not reported for Age 17 years or less
eGFR Range (mL/min/BSA)
Interpretive Data
90 or greater
Stage 1: Normal or increased eGFR
60-89
Stage 2: Mildly decreased eGFR
30-59
Stage 3: Moderately descreased eGFR
15-29
Stage 4: Severely decreased eGFR
Less than 15
Stage 5: Kidney Failure
Compliance Category
FDA
Note
Additional information related to the test.
If the patient's age and/or gender is unknown or is 18 years or younger, then Cystatin C Reflex will not be ordered. If age is greater than 18, Cystatin C reflex will be added at no additional charge.
Hotline History
N/A
CPT Codes
The American Medical Association Current Procedural Terminology (CPT) codes published in ARUP's Laboratory Test Directory are provided for informational purposes only. The codes reflect our interpretation of CPT coding requirements based upon AMA guidelines published annually. CPT codes are provided only as guidance to assist clients with billing. ARUP strongly recommends that clients confirm CPT codes with their Medicare administrative contractor, as requirements may differ. CPT coding is the sole responsibility of the billing party. ARUP Laboratories assumes no responsibility for billing errors due to reliance on the CPT codes published.
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
Aliases
Other names that describe the test. Synonyms.
Cystatin C, Serum with Reflex to Estimated Glomerular Filtration Rate (eGFR)
Connect Sign In
