Table 1 Diagnostic criteria for tubulointerstitial nephritis and uveitis syndrome

The diagnosis of TINU syndrome requires the presence of both acute interstitial nephritis (AIN) and uveitis, without other known systemic diseases that can cause either interstitial nephritis or uveitis

Cases are categorized further as “definite,” “probable,” or “possible” on the basis of (1) the diagnostic criteria for AIN as defined below and (2) the clinical characteristics of uveitis as defined below

Definite TINU syndrome

• AIN diagnosed histopathologically or clinically (complete criteria) and typical uveitis

Probable TINU syndrome

• AIN diagnosed histopathologically and atypical uveitis

   or

• AIN diagnosed clinically (incomplete criteria) and typical uveitis

Possible TINU syndrome

• AIN diagnosed clinically (incomplete criteria) and atypical uveitis

Diagnostic criteria for acute interstitial nephritis

• Histopathologic diagnosis: renal biopsy consistent with tubulointerstitial nephritis

• Clinical diagnosis:^a presence of the following criteria (a case is considered to have “complete criteria” if the three factors listed below are present; a case is considered to have “incomplete criteria” if fewer than three factors listed below are present):

  1. Abnormal renal function (elevated serum creatinine or decreased creatinine clearance)

  2. Abnormal urinalysis: increased beta-2 microglobulin, low-grade proteinuria [a level below that seen in patients with nephrotic syndrome (2+ or less on a semiquantitative test, or a spot urinary protein-to-urinary creatinine ratio of < 3, or < 3.0 g protein/24 hours in an adult or < 3.5 g protein/1.73 m²/24 hours in a child)], urinary eosinophils, pyuria or hematuria without infection, urinary white cell casts, or normoglycemic glucosuria

  3. A systemic illness lasting > 2 weeks, characterized by a combination of the following symptoms and laboratory findings:

   a. Signs and symptoms: fever, weight loss, anorexia, malaise, fatigue, rash, abdominal or flank pain, arthralgia, or myalgia

   b. Laboratory findings: evidence of anemia, abnormal liver function, eosinophilia, or Westergren erythrocyte sedimentation rate > 40 mm/hour

Uveitis characteristics

• Typical

  1. Bilateral anterior uveitis with or without intermediate uveitis or posterior uveitis

  2. Onset of uveitis ≤ 2 months before or ≤ 12 months after AIN

• Atypical

  1. Unilateral anterior uveitis or intermediate uveitis or posterior uveitis or a combination of these categories

  2. Onset of uveitis > 2 months before or > 12 months after AIN