Cogan Syndrome Vasculitis - Cogan Syndrome

Diagnosis

Indications for Testing

  • Rapid onset of sensorineural hearing loss, eye inflammation, symptoms of vasculitis

Laboratory Testing

  • No formal criteria or confirmatory test for the diagnosis of Cogan syndrome (CS)
  • Nonspecific testing – helpful in excluding other diagnoses
    • Initial assessment
      • Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) – elevated in ~50% of patients with active disease
    • Rule out other disease processes
      • Renal disorders – urinalysis, urea nitrogen, creatinine
      • Other types of vasculitis – anti-neutrophil cytoplasmic antibody (ANCA)
      • Connective tissue disease – anti-nuclear antibody (ANA), CBC
    • Rule out infections associated with hearing loss
      • Treponema pallidum testing
        • Presence of interstitial keratitis and/or acute sensorineural hearing loss combined with negative testing for syphilis is highly suggestive of CS
      • HIV testing

Imaging Studies

  • Angiogram – identify aortitis if symptoms present 

Differential Diagnosis

Clinical Background

Cogan syndrome (CS) is a rare vasculitis that typically manifests as an ophthalmic disorder (interstitial keratitis) and/or an audiovestibular disorder. It is categorized as a variable vessel vasculitis (Chapel Hill 2012).

Epidemiology

  • Incidence – rare; ~250 cases reported
  • Age – children (rare) and young adults in 20s-30s
  • Sex – M:F, equal

Pathophysiology

  • Inflammation in all vessel sizes (small, medium, large)
  • Primary ocular target – small vessels in the vascularized layers of the anterior globe, episclera, sclera and uveitis

Clinical Presentation

  • Constitutional – headache, fever, arthralgia, arthritis
  • Ophthalmologic – interstitial keratitis, iritis, uveitis, episcleritis (generally reversible)
  • Audiovestibular – Ménière-like syndrome (vertigo, tinnitus, ataxia) with or without sudden sensorineural hearing loss; frequently results in deafness
  • Vasculitis – occurs in 10-20% of patients
  • Cardiovascular – aortic disease; life threatening in small percent  of cases

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

May help in ruling out infectious process

   
Urinalysis, Complete 0020350
Method: Reflectance Spectrophotometry/Microscopy

Screen for hematuria, proteinuria, and RBC casts

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

Initial evaluation for suspected vasculitis

   
C-Reactive Protein 0050180
Method: Quantitative Immunoturbidimetry

Initial evaluation for suspected vasculitis

   
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

Confirm presence of ANCA-associated vasculitis

If screen is positive, titer and MPO/PR-3 antibodies testing will be added to aid in antibody determination

   
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

Rule out connective tissue disease

All ELISA results reported as "Detected" are further tested by IFA

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

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

 
Urea Nitrogen, Serum or Plasma 0020023
Method: Quantitative Spectrophotometry

Assess for  renal disease

   
Creatinine, Serum or Plasma 0020025
Method: Quantitative Enzymatic

Assess for  renal disease

   
Rapid Plasma Reagin (RPR) with Reflex to Titer and TP-PA Confirmation 0050478
Method: Semi-Quantitative Charcoal Agglutination/Semi-Quantitative Particle Agglutination

Rule out syphilis

   
Human Immunodeficiency Virus Types 1 and 2 (HIV-1, HIV-2) Antibodies by CIA with Reflex to HIV-1 Antibody Confirmation by Western Blot 2005377
Method: Qualitative Chemiluminescent Immunoassay/Qualitative Western Blot

Rule out HIV