Test Catalog

Test Id : AHUSD

Atypical Hemolytic Uremic Syndrome Complement Panel, Serum and Plasma

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

Detecting deficiencies in the alternative pathway that can cause atypical-hemolytic uremic syndrome, dense deposit disease, and C3 glomerulonephritis

 

A second-tier test that aids in the differential diagnosis of thrombotic microangiopathies

Profile Information
A profile is a group of laboratory tests that are ordered and performed together under a single Mayo Test ID. Profile information lists the test performed, inclusive of the test fee, when a profile is ordered and includes reporting names and individual availability.

Test Id Reporting Name Available Separately Always Performed
INTGA AHUS Interpretation No Yes
COM3 Complement, Total, S Yes, (order COM) Yes
AH503 Alternative Complement Path Func, S Yes, (order AH50) Yes
C3HUS Complement C3, S Yes, (order C3) Yes
C4HUS Complement C4, S Yes, (order C4) Yes
FBCA Factor B Complement Antigen, S No Yes
FHCA Factor H Complement Antigen, S No Yes
C4D C4d Complement, P No Yes
CBB CBb Complement, P No Yes
SC5B9 SC5b-9 Complement, P Yes, (C5B9) Yes

Reflex Tests
Lists tests that may or may not be performed, at an additional charge, depending on the result and interpretation of the initial tests.

Test Id Reporting Name Available Separately Always Performed
C1Q Complement C1q, S Yes No
C1QFX C1Q Complement, Functional, S Yes No
C2FXN C2 Complement, Functional, S, NR Yes No
C3FX C3 Complement, Functional, S Yes No
C4FX C4 Complement, Functional, S Yes No
C5FX C5 Complement, Functional, S Yes No
C6FX C6 Complement, Functional, S Yes No
C7FX C7 Complement, Functional, S Yes No
C8FX C8 Complement, Functional, S Yes No
C9FX C9 Complement, Functional, S Yes No
C5AG2 C5 Complement, Antigen, S Yes, (order C5AG) No

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

C3HUS, C4HUS, FBCA, FHCA: Nephelometry

COM3: Automated Liposome Lysis Assay

AH503, C4D, CBB, SC5B9: Enzyme-Linked Immunosorbent Assay (ELISA)

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

aHUS Complement Panel, S and P

Specimen Type
Describes the specimen type validated for testing

Plasma Na Cit

Serum Red

Ordering Guidance

This test should be performed prior to treatment initiation and in the absence of therapy with complement inhibitors, such as eculizumab or ravulizumab. Complement inhibitors will affect performance of these assays.

 

For evaluating patients with possible thrombotic microangiopathies (TMA), the recommended first-tier test is ADM13 / ADAMTS13 Activity and Inhibitor Profile, Plasma. This test should be a second-tier test for TMA.

 

For patients who have received eculizumab or need to monitor response to eculizumab therapy, the recommended test is ECUMP / Eculizumab Monitoring Panel, Serum. Soluble membrane attack complex (sMAC) should not be used as a standalone assay to monitor eculizumab efficiency.

ORDER QUESTIONS AND ANSWERS

Question ID Description Answers
ECPRO Is Eculizumab or Ravulizumab taken?

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

Both plasma and serum are required for this test.

 

Patient Preparation:

1. Fasting preferred.

2. Samples should not be collected earlier than 48 hours following plasma exchange.

 

Supplies: Sarstedt 5 mL Aliquot Tube (T914)

 

Specimen Type: Plasma

Collection Container/Tube: Light-blue top (3.2% sodium citrate)

Submission Container/Tube: Plastic vial

Specimen Volume: 1.5 mL

Collection Instructions:

1. Immediately after specimen collection, place the tube on wet ice.

2. Centrifuge; 1500 x g for 10 minutes at 4 degrees C and aliquot plasma into plastic vial.

3. Freeze specimen within 30 minutes.

 

Specimen Type: Serum

Collection Container/Tube: Red top (serum gel/SST are not acceptable)

Submission Container/Tube: Plastic vial

Specimen Volume: 1.5 mL

Collection Instructions:

1. Immediately after specimen collection, place the tube on wet ice.

2. Centrifuge at 4 degrees C and aliquot serum into 5 mL plastic vial.

3. Freeze specimen within 30 minutes.

Forms

If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:

-Renal Diagnostics Test Request (T830)

-Coagulation Test Request (T753)

Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the Testing Laboratory

Serum, Plasma: 1 mL each

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

Gross hemolysis OK
Gross lipemia Reject
Gross icterus OK

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 Na Cit Frozen (preferred) 14 days
Serum Red Frozen (preferred) 14 days

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

Detecting deficiencies in the alternative pathway that can cause atypical-hemolytic uremic syndrome, dense deposit disease, and C3 glomerulonephritis

 

A second-tier test that aids in the differential diagnosis of thrombotic microangiopathies

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

Individuals presenting with thrombotic microangiopathies (TMA) require clinical testing to identify the underlying cause. Thrombotic thrombocytopenic purpura (TTP) and hemolytic uremic syndrome (HUS) are both acute syndromes with many overlapping clinical features. Reduced levels of ADAMTS13 (a disintegrin and metalloproteinase with thrombospondin type 1 motives, member 13) activity is associated with TTP and is one laboratory feature that distinguishes TTP from HUS. HUS can also have a number of causes; one of the rarer forms of disease is caused by defects in the alternative pathway of the complement system, so called atypical-HUS (aHUS). Patients with defective alternative pathway regulation can benefit from biologics that suppress the complement system.

 

The purpose of this panel is to aid in the differential diagnosis of TMA. The suggested approach is to rule-out other causes of TMA first, since aHUS is one of the rarer causes of TMA. Additionally, the assays can be used in the setting of membranoproliferative glomerulonephritis (MPGN) and can help distinguish between immune-complex mediated or complement-mediated kidney disease. MPGN mediated by immune-complexes are ones resulting from infectious processes, autoimmune diseases, or monoclonal gammopathies; whereas complement-mediated MPGN can be subdivided in C3 glomerulonephritis and dense deposit disease, based on electron microscopy of the kidney biopsy histological findings. Despite phenotypic differences, these glomerular diseases share dysfunction of the alternative pathway as the defining pathophysiology.

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.

FACTOR B COMPLEMENT ANTIGEN

15.2-42.3 mg/dL

 

SC5b-9 COMPLEMENT

< or =250 ng/mL

 

FACTOR H COMPLEMENT ANTIGEN

18.5 to 40.8 mg/dL

 

C4d COMPLEMENT ACTIVATION FRAGMENT

< or =9.8 mcg/mL

 

CBb COMPLEMENT ACTIVATION FRAGMENT

< or =1.6 mcg/mL

 

COMPLEMENT C4

14-40 mg/dL

 

COMPLEMENT C3

75-175 mg/dL

 

ALTERNATIVE COMPLEMENT, PATHWAY (AH50) FUNCTIONAL

> or =46% normal

 

COMPLEMENT, TOTAL

30-75 U/mL

Interpretation
Provides information to assist in interpretation of the test results

An interpretive report will be included.

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

As with all complement assays, proper sample handling is of utmost importance to ensure that the complement system is not activated before clinical testing.

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

1. Daha MR: Role of complement in innate immunity and infections. Crit Rev Immunol. 2010;30(1):47-52. doi: 10.1615/critrevimmunol.v30.i1.30

2. Prohaszka Z, Varga L, Fust G: The use of "real-time" complement analysis to differentiate atypical haemolytic uraemic syndrome from other forms of thrombotic microangiopathies. Br J Haematol. 2012;158(3):424-425. doi: 10.1111/j.1365-2141.2012.09168.x

3. Cataland SR, Holers VM, Geyer S, Yang S, Wu HM: Biomarkers of terminal complement activation confirm the diagnosis of aHUS and differentiate aHUS from TTP. Blood. 2014;123(24):3733-3738. 10.1182/blood-2013-12-547067

4. Go RS, Winters JL, Leung N, et al: Thrombotic microangiopathy care pathway: A consensus statement for the Mayo Clinic Complement Alternative Pathway-Thrombotic Microangiopathy (CAP-TMA) Disease-Oriented Group. Mayo Clin Proc. 2016;91(9):1189-1211. doi: 10.1016/j.mayocp.2016.05.015

5. Willrich MAV, Andreguetto BD, Sridharan M, et al: The impact of eculizumab on routine complement assays. J Immunol Methods. 2018;460:63-71. doi: 10.1016/j.jim.2018.06.010

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

Complement, Total:

An automated method is performed using liposomes as the target for the serum complement system. The dinitrophenyl (DNP)-labeled liposomes are sensitized with antibody to DNP. Serum complement causes lysis and release of entrapped glucose-6-phosphate dehydrogenase. Glucose-6-phosphate dehydrogenase reacts with glucose-6-phosphate and nicotinamide adenine dinucleotide (NAD). NAD is reduced to NADH and the conversion is measured at 340 nm. The assay correlates with the CH50 assay based on sheep RBC lysis, has lower variability, and is simpler to perform.(Package insert: Fujifilm Autokit CH50. Fujifilm Wako Pure Chemical Corporation; 04/01/2018; Yamamoto S, Kubotsu K, Kida M, et al: Automated homogeneous liposome-based assay system for total complement activity. Clin Chem. 1995;41:586-590)

 

Alternative Complement, Pathway Functional:

The Wieslab enzyme-linked immunosorbent assay (ELISA) complement assay for the alternative pathway combines principles of the hemolytic assay for complement activation with the use of labeled antibodies specific for neoantigens produced as a result of complement activation. The micro titer plate strips are coated with lipopolysaccharide (LPS). Patient serum is diluted in diluent containing specific blocker to ensure that only the alternative pathway is activated. During the first incubation, the diluted patient serum in the wells is activated by the coating. The wells are then washed and C5b-9 (membrane attack complex: MAC) is detected with a specific alkaline phosphatase labeled antibody to the neoantigen expressed during MAC formation. After a final wash, an alkaline phosphatase substrate is added. The amount of alternative pathway complement activity correlates with the color intensity of the solution and is measured in terms of absorbance (optical density).(Frazer-Abel A, Sepiashvili L, Mbughuni MM, Willrich MA: Overview of laboratory testing and clinical presentations of complement deficiencies and dysregulation. Adv Clin Chem. 2016;77:1-75. doi: 10.1016/bs.acc.2016.06.001)

 

Complements C3 and C4; Factor B and Factor H Complement Antigens:

In these Siemens Nephelometer II methods, the light scattered onto the antigen-antibody complexes is measured. The intensity of the measured scattered light is proportional to the amount of antigen-antibody complexes in the sample under certain conditions. If the antibody volume is kept constant, the signal behaves proportionally to the antigen volume.

 

A reference curve is generated by a standard with a known antigen content on which the scattered light signals of the samples can be evaluated and calculated as an antigen concentration. Antigen-antibody complexes are formed when a sample containing antigen and the corresponding antiserum are put into a cuvette. A light beam is generated with a light emitting diode (LED), which is transmitted through the cuvette. The light is scattered onto the immuno-complexes that are present. Antigen and antibody are mixed in the initial measurement, but no complex is formed yet. An antigen-antibody complex is formed in the final measurement.

 

The result is calculated by subtracting value of the final measurement from the initial measurement. The distribution of intensity of the scattered light depends on the ratio of the particle size of the antigen-antibody complexes to the radiated wavelength.(Instruction manual: Siemens Nephelometer II Operations. Siemens, Inc; Version 2.3, 2008; Addendum to the Instruction Manual 2.3, 08/2017))

 

C4d Complement Activation Fragment:

Microtiter plates are coated with monoclonal antibody specific to the C4d fragment of the fourth component of the complement cascade. Controls, standards, and patient samples are exposed to the plate. After washing the plate, a horseradish peroxidase-conjugated polyclonal C4d antibody is added followed by a substrate to initiate color change.(Package insert: MicroVue C4d Fragment EIA Kit. Quidel Corporation; A009000EN00 10/2017)

 

CBb Complement Activation Fragment:

Microtiter plates are coated with monoclonal antibody specific to the complement factor Bb (CBb) fragment of the fourth component of the complement cascade. Controls, standards, and patient samples are exposed to the plate. After washing the plate, a horseradish peroxidase-conjugated polyclonal CBb antibody is added followed by a substrate to initiate color change.(Package insert: MicroVue CBb Plus EIA Kit. Quidel Corporation; 027002EN00 09/2016)

 

SC5b-9 Complement Activation Complex:

Microtiter plates are coated with monoclonal antibody specific to the C9 ring of the SC5b-9 complex. Controls, standards, and patient samples are exposed to the plate. After washing the plate, a horseradish peroxidase-conjugated anti-SC5b-9 complex antibody is added followed by a substrate to initiate color change.(Package insert: MicroVue SC5b-9 Plus EIA Kit. Quidel Corporation; 020001EN00 05/2017)

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

No

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.

Varies

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.

12 to 21 days

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

Rochester

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 Regional Manager. 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.

This test was developed, and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved 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.

86160 x 7

86161

86162

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
AHUSD aHUS Complement Panel, S and P In Process
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.
62584 C4d Complement, P 39565-7
62585 CBb Complement, P 4517-9
FBCA Factor B Complement Antigen, S 2269-9
FHCA Factor H Complement Antigen, S 4519-5
62586 SC5b-9 Complement, P 93244-2
38316 Alternative Complement Path Func, S 74520-8
COM3 Complement, Total, S 4532-8
C3HUS Complement C3, S 4485-9
C4HUS Complement C4, S 4498-2
39844 AHUS Interpretation 69048-7
ECPRO Is Eculizumab or Ravulizumab taken? 86955-2

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