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Test Code CTDC Connective Tissue Diseases Cascade, Serum

Profile Information

Test ID Reporting Name Available Separately Always Performed
ANA2 Antinuclear Ab, S Yes Yes
CCP Cyclic Citrullinated Peptide Ab, S Yes Yes
IM_01 Interpretation No Yes

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
CMA Centromere Ab, IgG, S Yes No
CASMT ANA2 Cascade No No
RIB Ribosome P Ab, IgG, S Yes No
ENAE Ab to Extractable Nuclear Ag Eval,S Yes No
ADNA1 dsDNA Ab, IgG, S Yes No

Testing Algorithm

If antinuclear antibodies are greater than or equal to 3.0 U, then antibodies to double-stranded DNA (dsDNA), extractable nuclear antigen evaluation, ribosome P, and centromere are performed at an additional charge.

 

For more information see Connective Tissue Disease Cascade.

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Serum


Specimen Required


Collection Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Collection Information: Centrifuge and aliquot serum into plastic vial.


Specimen Minimum Volume

0.7 mL

Specimen Stability Information

Specimen Type Temperature Time
Serum Refrigerated (preferred) 21 days
  Frozen  21 days

Reference Values

ANTINUCLEAR ANTIBODIES (ANA)

≤1.0 U (negative)

1.1-2.9 U (weakly positive)

3.0-5.9 U (positive)

≥6.0 U (strongly positive)

Reference values apply to all ages.

 

CYCLIC CITRULLINATED PEPTIDE ANTIBODIES, IgG

<20.0 U (negative)

20.0-39.9 U (weak positive)

40.0-59.9 U (positive)

≥60.0 U (strong positive) 

Reference values apply to all ages.

Day(s) Performed

Monday through Saturday

CPT Code Information

86038

86200

83516-Centromere (if appropriate)

83516-Ribosome (if appropriate)

86225-ds-DNA AB IgG, Serum (if appropriate)

86235 x 6-RNP, Sm, SS-B, SS-A, Jo 1, and Scl 70 (if appropriate)

Clinical Information

The following diseases are often referred to as connective tissue diseases (CTD): rheumatoid arthritis, systemic lupus erythematosus, systemic sclerosis including CREST syndrome (calcinosis, Raynaud phenomenon, esophageal dysmotility, sclerodactyly, and telangiectasia), Sjogren syndrome, mixed connective tissue disease, and idiopathic inflammatory myopathies. CTD (also known as systemic rheumatic diseases) are characterized by immune-mediated inflammation that involves the joints, skin, and visceral organs. These diseases are also accompanied by antibodies to a host of nuclear and cytoplasmic autoantigens.

 

The diagnosis of any CTD is based on clinical signs and symptoms and characteristic radiographic, histopathologic, and serologic findings. Certain CTD are characterized by autoantibodies that are highly specific for individual diseases as outlined in the Table. CTD often present clinically with signs and symptoms that are nonspecific, including constitutional signs such as fever, weight loss, fatigue, and arthralgias.

 

Table. Autoantibodies and Clinical Associations with Specific Connective Tissue Diseases

Cyclic citrullinated peptide antibodies

Rheumatoid arthritis

Double-Stranded DNA (dsDNA)

Systemic lupus erythematosus (SLE)

Smith (Sm)

SLE

Ribosome P

SLE

SS-B/La

Sjogren syndrome (SjS)

SS-A/Ro (Ro52 or Ro60)

SjS, SLE, systemic sclerosis (SSc), antisynthetase syndrome

RNP 68 and A (RNP)

Mixed connective tissue disease

Topoisomerase 1 (topo-1, Scl-70)

SSc

Histidyl tRNA synthetase (JO1)

Idiopathic inflammatory myositis (commonly anti-synthetase syndrome)

Centromere B

SSc (most commonly the limited cutaneous forms: LcSSc)

 

In this testing cascade, serum is tested initially for the presence of antinuclear antibodies (ANA) and for cyclic citrullinated peptide (CCP) antibodies. The presence of CCP antibodies indicates a strong likelihood of rheumatoid arthritis (RA).(1) However, additional testing for rheumatoid factor, which is not included in the cascade, is important for optimal diagnosis as per the 2010 American College of Rheumatology/European League Against Rheumatism RA classification criteria.(2) The presence of ANA supports the possibility of a CTD, and the level of ANA is used to identify sera for second-order testing for antibodies to dsDNA and the other autoantigens. The decision threshold for performing second-order tests is based on empirical data derived from testing patients with varying levels of ANA and is chosen to minimize testing in situations in which positive results for dsDNA and other antibodies is very unlikely.(3) However, a negative ANA enzyme immunoassay result does not rule out a diagnosis of CTD as has been reported in a number of studies. Therefore, in patients with a strong clinical suspicion of CTD, testing for ANA by indirect immunofluorescence assay may be warranted.(4,5)

Report Available

3 to 4 days

Reject Due To

Gross hemolysis Reject
Gross lipemia Reject
Gross icterus OK

Method Name

Enzyme-Linked Immunosorbent Assay (ELISA)