Connective Tissue Diseases

Diagnosis

Indications for Testing

  • Patient with systemic symptoms, including arthralgias, arthritis, skin rashes, anemia, renal dysfunction, pleuritis, pericarditis

Laboratory Testing

  • Nonspecific testing
    • CBC – rule out infection
    • C-reactive protein (CRP)
    • Antinuclear antibodies (ANA) testing
      •  ANA, IgA, by ELISA
        • Negative – possible scenarios
          • No connective tissue disease (CTD) present
          • False-negative result – consider systemic sclerosis (scleroderma SSc), polymyositis/dermatomyositis (PM/DM), inactive systemic lupus erythematosus (SLE)
            • If strong suspicion for CTD, consider disease-specific antibody tests or panels
          • Positive – ANA HEp-2, IgG, by IFA (result pattern suggests underlying disease)
            • ANA reported patterns and diagnoses
              • Centromere – limited cutaneous scleroderma (lcSSc), CREST (calcinosis, Raynaud phenomenon, esophageal dysmotility, sclerodactyly, telangiectasia)
              • Cytoplasmic – PM, DM, SLE, SSc
              • Peripheral/rim/homogenous – SLE, drug-induced lupus erythematosus (DIL)
              • Nucleolar – SLE, SSc, PM DM
              • Speckled – SLE, Sjögren syndrome, mixed connective tissue disease (MCTD)/undifferentiated connective tissue disease (UCTD), diffuse cutaneous scleroderma (dcSSc), unidentified specificities or markers of low prevalence in CTD – see Connective Tissue Disease Testing Algorithm for more specific antibody testing patterns
            • False-positive results may be induced by age, certain infections, cancers, and drugs
            • ANA may be positive in inflammatory diseases (eg, autoimmune liver diseases)
            • Titer level has no bearing on diagnosis or disease severity once it is above established normal level
    • Other testing
      • Rheumatoid factor IgM antibodies – if musculoskeletal complaints are present
      • If suspicion for connective tissue disease is low, consider drug-induced lupus erythematosus (DIL), chronic autoimmune disease, chronic hepatitis C virus
      • Urinalysis – rule out glomerulonephritis associated with connective tissue disease
      • Anti-neutrophil cytoplasmic antibodies (ANCA) – rule out vasculitis associated with connective tissue disease
  • Differential Diagnosis

Monitoring

  • Once diagnosis has been made, use monitoring tests based on organ involvement
    • Urinalysis acceptable screen for renal disease
    • If cytopenias present, follow with sequential CBCs
    • Certain treatment drugs require liver function testing

Clinical Background

Several autoimmune connective tissue diseases may present with similar features. These diseases include systemic lupus erythematosus, Sjögren syndrome, mixed connective tissue disease, systemic sclerosis (scleroderma), inflammatory myopathies (polymyositis/dermatomyositis [PM/DM]), and undifferentiated connective tissue disease.

Epidemiology

  • Incidence – 15-50/100,000, depending on disease
  • Age – onset is 15-40 years; peak onset in 20s
  • Sex – M<F, 1:6-10  

Pathophysiology

  • Circulating antigen-antibody complexes affect a variety of organs
  • Multisystem disease presentation
  • Antigen/antibody complexes affect a variety of organs in connective tissue diseases
  • ANA antibodies are the most common antibodies and may precede the onset of connective tissue disease 
  • Certain antibodies may show specificity for certain diseases (eg, SSA 52, SSA 60, and SSB antibodies for Sjögren syndrome)
  • ANA antibodies are not specific for connective tissue disease and may also be associated with
    • Infectious diseases
    • Cancers
    • Other autoimmune disorders (eg, autoimmune liver disease)
    • Advanced age

Clinical Presentation

  • Cardiopulmonary – pleuritis, pericarditis, fibrosis, chest pain
  • Constitutional – fever, anorexia, weight loss
  • Dermatologic – skin rashes, Raynaud phenomenon, photosensitivity
  • Gastrointestinal – gastroesophageal reflux disease
  • Hematologic – cytopenias (involving neutrophils, erythrocytes, and platelets)
  • Musculoskeletal – arthralgias, arthritis, synovitis, myopathy
  • Neurologic – seizures, encephalopathy
  • Otorhinolaryngologic – sicca syndrome, oral ulcers
  • Renal – proteinuria, glomerulonephritis

Pediatrics

Clinical Background

Epidemiology

  • Incidence – varies by disease but lower than in adults
  • Sex – M<F for most disorders
  • Age – presents more often >10 years

Clinical Presentation

  • Cardiopulmonary – chest pain, pericarditis, pleuritis
  • Constitutional – fever, anorexia, weight loss (most common)
  • Dermatologic – skin rash, Raynaud syndrome, photosensitivity
  • Gastrointestinal – abdomen pain, diarrhea, hepatitis
  • Musculoskeletal – arthralgias, arthritis, synovitis, myopathy, weakness

Diagnosis

Indications for Testing

  • Appropriate clinical presentation, including arthritis, arthralgias, skin rashes, anemia, pleuritis, pericarditis

Laboratory Testing

  • Nonspecific testing
    • Refer to Diagnosis tab
  • ANA testing
    • Refer to Diagnosis tab and Connective Tissue Disease Testing Algorithm
  • Other testing
    • Rheumatoid factor IgM antibodies – rule out juvenile idiopathic arthritis if musculoskeletal complaints are present

Differential Diagnosis

Indications for Laboratory Testing

  • Tests generally appear in the order most useful for common clinical situations
  • Click on number for test-specific information in the ARUP Laboratory Test Directory
Test Name and Number Recommended Use Limitations Follow Up
CBC with Platelet Count and Automated Differential 0040003
Method: Automated Cell Count/Differential

Use in evaluation of connective tissue disease

If cytopenias present, use sequentially for monitoring

   
C-Reactive Protein 0050180
Method: Quantitative Immunoturbidimetry

Preferred test to detect inflammatory processes

   
Anti-Nuclear Antibodies (ANA), IgG by ELISA with Reflex to ANA, IgG by IFA 0050080
Method: Qualitative Enzyme-Linked Immunosorbent Assay/Semi-Quantitative Indirect Fluorescent Antibody

Initial screen for connective tissue diseases

Detects antibodies against dsDNA, histone, SS-A (Ro), SS-B (La), Smith, snRNP/Sm, Scl-70, Jo-1, centromere, and an extract of lysed HEp-2 cells

ELISA results reported as "Detected" are further evaluated by IFA

Results are not disease specific

ANA ELISA assays have lower sensitivities for antibodies associated with nucleolar and specked ANA-IFA patterns

 
Anti-Nuclear Antibody (ANA), IgG by IFA with Reflex by IFA Pattern 2008467
Method: Semi-Quantitative Indirect Fluorescent Antibody/Qualitative Enzyme-Linked Immunosorbent Assay/Semi-Quantitative Enzyme-Linked Immunosorbent Assay/Semi-Quantitative Multiplex Bead Assay/Semi-Quantitative Immunoblot

Initial screen for connective tissue diseases

Test begins with IFA IgG; depending on findings, one or more reflexive tests may be added:

  • Double-stranded DNA (dsDNA) antibody, IgG, by ELISA
  • Double-stranded DNA (dsDNA) antibody, IgG, by IFA (using Crithidiae luciliae)
  • Chromatin antibody, IgG
  • RNP (U1) (ENA) antibody, IgG
  • Smith (ENA) antibody, IgG
  • SSA 52 (Ro) (ENA) antibody, IgG
  • SSA 60 (Ro) (ENA) antibody, IgG
  • SSB (La) (ENA) antibody, IgG
  • Scleroderma (Scl-70) (ENA) antibody, IgG
  • PM/Scl-100 antibody, IgG, by immunoblot
  • RNA polymerase III antibody, IgG
   
Connective Tissue Diseases Profile 0051668
Method: Semi-Quantitative Multiplex Bead Assay

Order following positive ANA result

Components include Sm (ENA) antibody; RNP (U1) (ribonucleic protein); SSA (Ro); SSB (La); Jo-1; ribosomal P protein; centromere; and scleroderma (Scl-70)

   
Systemic Sclerosis Panel 2012057
Method: Semi-Quantitative Indirect Fluorescent Antibody/Semi-Quantitative Multiplex Bead Assay/ Semi-Quantitative Enzyme-Linked Immunosorbent Assay

Use to evaluate systemic sclerosis

Components include anti-nuclear antibody (ANA); scleroderma (Scl-70); and RNA polymerase III

Negative antibody test result does not exclude systemic sclerosis

 
Myositis-Specific Antibody Panel 2010862
Method: Qualitative Immunoprecipitation/Semi-Quantitative Multiplex Bead Assay

Useful for confirming a diagnosis of myositis or dermatomyositis

Components include Jo-1; Mi-2; PL-7; PL-12; P155/140; EJ; SRP; and OJ

   
Myositis Antibody Comprehensive Panel 2010851
Method: Qualitative Immunoprecipitation/Semi-Quantitative Multiplex Bead Assay

Differential evaluation of patients with PM/DM and/or other connective tissue diseases or overlapping syndromes

Components include PM/Scl-100; SSA 52 and 60 (Ro) (ENA) IgG; RNP (U1) (ribonucleic protein) (ENA) IgG; Jo-1 IgG; Mi-2; PL-7; PL-12; P155/140; EJ; SRP; Ku; U2; and OJ

   
Rheumatoid Arthritis Panel 2003277
Method: Semi-Quantitative Enzyme-Linked Immunosorbent Assay/Immunoturbidimetry

Evaluate for rheumatoid arthritis

Components include cyclic citrullinated peptide (CCP) antibody, IgG, and rheumatoid factor

   
Anti-Neutrophil Cytoplasmic Antibody with Reflex to Titer and MPO/PR-3 Antibodies 2002068
Method: Semi-Quantitative Indirect Fluorescent Antibody/Semi-Quantitative Multiplex Bead Assay

Evaluate for vasculitis

If screen is positive, titer and MPO/PR-3 antibodies testing will be added

   
Additional Tests Available
 
Click the plus sign to expand the table of additional tests.
Test Name and NumberComments
Urinalysis, Complete 0020350
Method: Reflectance Spectrophotometry/Microscopy

Screen for renal disease; rule out glomerulonephritis

Hepatic Function Panel 0020416
Method: Quantitative Enzymatic/Quantitative Spectrophotometry

Monitor drug treatment

Sedimentation Rate, Westergren (ESR) 0040325
Method: Visual Identification

Nonspecific test to evaluate connective tissue disease and monitor inflammation

Cyclic Citrullinated Peptide (CCP) Antibody, IgG 0055256
Method: Semi-Quantitative Enzyme-Linked Immunosorbent Assay

Diagnose rheumatoid arthritis (RA) or evaluate likely development of RA in patients with undifferentiated arthritis

RNP (U1) (Ribonucleic Protein) (ENA) Antibody, IgG 0050470
Method: Semi-Quantitative Multiplex Bead Assay
Secondary screen based on ANA test
Anti-Nuclear Antibodies (ANA), IgG by ELISA with Reflexes to ANA, IgG by IFA and to dsDNA, RNP, Smith, SSA 52, SSA 60, and SSB Antibodies, IgG 0050317
Method: Qualitative Enzyme-Linked Immunosorbent Assay/Semi-Quantitative Indirect Fluorescent Antibody/Semi-Quantitative Multiplex Bead Assay

Reflex pattern – if ANA IgG is detected by ELISA, then ANA IgG by IFA (using HEp-2 substrate) will be added; if ANA, IgG by IFA is confirmed positive with a titer of 1:40 or greater, then a titer and pattern will be reported; in addition, samples positive for ANA, IgG by IFA will reflex to double-stranded DNA (dsDNA) antibody, IgG by ELISA, RNP (U1) (Ribonucleic Protein) (ENA) antibody, IgG, Smith (ENA) antibody, IgG, SSA 52 and 60 (Ro) (ENA) antibodies, IgG, and SSB (La) (ENA) antibody, IgG. If double-stranded DNA (dsDNA) antibody, IgG by ELISA is detected, then double-stranded DNA (dsDNA) antibody, IgG by IFA (using Crithidia luciliae) will be added

Extractable Nuclear Antigen Antibodies (RNP, Smith, SSA 52, SSA 60, and SSB) 0050652
Method: Semi-Quantitative Multiplex Bead Assay

Secondary screen based on ANA test results

Jo-1 Antibody, IgG 0099592
Method: Semi-Quantitative Multiplex Bead Assay

Secondary screen based on ANA test results

SSA 52 and 60 (Ro) (ENA) Antibodies, IgG 2012074
Method: Semi-Quantitative Multiplex Bead Assay

Order as secondary screen based on results of ANA test or if there is strong suspicion for Sjögren syndrome, SLE, or myositis, and ANA IFA is negative

PM/Scl-100 Antibody, IgG, by Immunoblot with Reflex to ANA IFA 2003040
Method: Semi-Quantitative Immunoblot/Semi-Quantitative Indirect Fluorescent Antibody

Secondary screen based on ANA test results

SSB (La) (ENA) Antibody, IgG 0050692
Method: Semi-Quantitative Multiplex Bead Assay

Secondary screen based on ANA test results

Double-Stranded DNA (dsDNA) Antibody, IgG by ELISA with Reflex to dsDNA Antibody, IgG by IFA 0050215
Method: Qualitative Enzyme-Linked Immunosorbent Assay/Semi-Quantitative Indirect Fluorescent Antibody

dsDNA antibodies are screened using an ELISA assay

If dsDNA antibodies are detected, then dsDNA Antibody IgG by IFA (using Crithidia luciliae) will be added

Smith (ENA) Antibody, IgG 0050085
Method: Semi-Quantitative Multiplex Bead Assay

Secondary screen based on ANA test results

Ribosomal P Protein Antibody 0099249
Method: Semi-Quantitative Multiplex Bead Assay
ssDNA Antibody, IgG 0099528
Method: Semi-Quantitative Enzyme-Linked Immunosorbent Assay

Secondary screen based on ANA test results

Histone Antibody, IgG 0050860
Method: Semi-Quantitative Enzyme-Linked Immunosorbent Assay
Lupus Comprehensive Reflexive Panel 0050119
Method: Quantitative Immunoturbidimetry/Semi-Quantitative Enzyme-Linked Immunosorbent Assay/Semi-Quantitative Indirect Fluorescent Antibody/Quantitative Chemiluminescent Immunoassay/Semi-Quantitative Multiplex Bead Assay

Reflex pattern – if antibodies are detected, then an IFA titer will be added; if confirmed by IFA, then specimen will be tested for TPO antibody, anti-Scl-70 (ENA), EIA, RNP antibody, IgG, Smith antibody, IgG, SSA 52 and 60 (Ro) antibodies, IgG, SSB (La) antibody, IgG and double-stranded DNA (dsDNA) antibody, IgG by ELISA; if dsDNA antibody, IgG by ELISA result is detected, then dsDNA antibody, IgG by IFA (using Crithidia luciliae) is added

Scleroderma (Scl-70) (ENA) Antibody, IgG 0050599
Method: Semi-Quantitative Multiplex Bead Assay

Secondary screen based on ANA test results

Centromere Antibody, IgG 0050714
Method: Semi-Quantitative Multiplex Bead Assay

Secondary screen based on ANA test results