Table 1.

Classification criteria of Sjögren’s syndrome (SS).

	2002 American-European Consensus Group (AECG) [9]	2012 Sjögren’s International Collaborative Clinical Alliance (SICCA) [10]	2016 American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) [2]
Item	I. Ocular symptoms: positive response ≥ 1 of the following questions:  1. Have you had daily, persistent, troublesome dry eyes for more than 3 months?  2. Do you have a recurrent sensation of sand or gravel in the eyes?  3. Do you use tear substitutes more than three times a day? II. Oral symptoms: positive response ≥ 1 of the following questions:  1. Have you had a daily feeling of dry mouth for more than 3 months?  2. Have you had recurrently or persistently swollen salivary glands as an adult?  3. Do you frequently drink liquids to aid in swallowing dry food? III. Ocular signs (objective evidence of ocular involvement): positive result ≥ 1 of the following two tests:  1. Schirmer’s I test, performed without anesthesia (<5 mm in 5 min)  2. Rose bengal score or other ocular dye scores (>4 according to van Bijsterveld’s scoring system) IV. Histopathology: In minor salivary glands, focal lymphocytic sialoadenitis, evaluated by an expert histopathologist, with a focus score >1, defined as a number of lymphocytic foci (which are adjacent to normal-appearing mucous acini and contain >50 lymphocytes) per 4 mm2 of glandular tissue V. Salivary gland involvement (objective evidence of salivary gland involvement): positive result ≥ 1 of the following diagnostic tests:  1. Unstimulated whole salivary flow (<1.5 mL in 15 min)  2. Parotid sialography showing the presence of diffuse sialectasias (punctate, cavitary, or destructive pattern), without evidence ofobstruction in the major ducts  3. Salivary scintigraphy showing delayed uptake, reduced concentration and/or delayed excretion of tracer VI. Autoantibodies: presence in the serum of antibodies to Ro(SSA) or La(SSB) antigens, or both	Positive serum anti-SSA (Ro) and/or anti-SSB (La) or positive rheumatoid factor and ANA ≥ 1:320 Labial salivary gland biopsy exhibiting focal lymphocytic sialadenitis with a focus score ≥ 1 focus/4 mm2 Keratoconjunctivitis sicca with ocular staining score ≥ 3	The classification of SS applies to any individual who meets the inclusion criteria, does not have any condition listed as exclusion criteria, and who has a score ≥ 4 when summing the weights from the following items: Labial salivary gland with focal lymphocytic sialadenitis and focus score ≥1.3 → 3 weights Anti-SSA (Ro) → 3 weights Ocular staining score ≥ 5 (or van Bijsterfeld score ≥ 4) on at least one eye → 1 weight Schirmer ≤ 5 mm/5 min on at least one eye → 1 weight Unstimulated whole saliva flow rate ≤ 0.1 mL/min → 1 weight
Inclusion criteria	For primary SS  a. The presence of any 4 of the 6 items is indicative of primary SS, as long as either item IV or VI is positive  b. The presence of any 3 of the 4 objective criteria items (that is, items III, IV, V, VI)  c. The classification tree procedure represents a valid alternative method for classification, although it should be more properly used in a clinical-epidemiological survey For secondary SS In patients with a potentially associated disease (for instance, another well-defined connective tissue disease), the presence of item I or item II plus any 2 from among items III, IV, and V		≥1 symptom of ocular or oral dryness (defined as a positive response to at least one of the following questions: (1) Have you had daily, persistent, troublesome dry eyes for more than 3 months? (2) Do you have a recurrent sensation of sand or gravel in the eyes? (3) Do you use tear substitutes more than 3 times a day? (4) Have you had a daily feeling of dry mouth for more than 3 months? (5) Do you frequently drink liquids to aid in swallowing dry food?), or suspicion of SS from the ESSDAI questionnaire (at least one domain with positive item)
Exclusion criteria	Past head and neck radiation treatment Hepatitis C infection Acquired immunodeficiency disease (AIDS) Pre-existing lymphoma Sarcoidosis Graft versus host disease Use of anticholinergic drugs (since a time shorter than 4-fold the half-life of the drug)	History of head and neck radiation treatment Hepatitis C infection AIDS Sarcoidosis Amyloidosis Graft versus host disease IgG4-related disease	History of head and neck radiation treatment Active Hepatitis C infection (with positive PCR) AIDS Sarcoidosis Amyloidosis Graft versus host disease IgG4-related disease

ESSDAI, EULAR Sjögren’s Syndrome Disease Activity Index; IgG, immunoglobulin G; PCR, polymerase chain reaction.