Sjogren’s or Sicca Syndrome and Mikulicz’s Disease or an IgG4-Related Disease

Sjogren’s or sicca syndrome (SS), is a progressive, inflammatory autoimmune disease affecting the exocrine glands. Clinical features include mucosal dryness presented as xerophthalmia (keratoconjuctivitis sicca), xerostomia, xerotrachea and vaginal dryness, major salivary gland enlargement, non-erosive polyarthritis and Raynaud’s phenomenon. The symptoms are mild from dryness of mucosal surfaces in some patients to very severe with involvement of many organs in others. The disease has increased mortality, due to extraglandular systemic involvement and often accompanying lymphoma. Laboratory tests show positive antinuclear antibodies, rheumatoid factor and anti Ro/SSA, anti La/SSB antibodies. Biopsy of the minor salivary glands is a gold standard in the diagnosis of SS. The focus score in an area of 4 mm2 describes focal aggregates of at least 50 lymphocytes. One present focus score represents a positive result. Structural damage on the eye surface is evaluated using the Lissamine green test. Patients with SS have a 44 times higher risk of developing lymphoma than normal control population. Extraglandular symptoms may be treated with GCS and immunosuppresive drugs in severe cases (CYC, AZA or MMF in pulmonary alveolitis, glomerulonephritis or severe neurological features). Mikulicz’s disease (MD) is an IgG4-related disease. Criteria of MD are: increased IgG4 level (>135 mg/dl), tissue biopsy with infiltration of IgG4 plasmocytes with fibrosis and sclerosis. Differences between MD and SS: MD does not show the same female predominance. Allergic rhinitis and autoimmune pancreatitis are seen more often in MD. There is an increased improvement after GCS treatment in patients with MD than with SS.

Keywords: Anti La/SSB antibodies, Anti Ro/SSA antibodies, Exocrine glands, Focus score, IgG4 level, IgG4-related disease, Keratoconjuctivitis sicca, Lymphoma, Major salivary gland enlargement, Mikulicz’s disease, Mucosal dryness, Non-erosive polyarthritis, Raynaud’s phenomenon, Sicca syndrome, Sjögren’s syndrome, Xerophthalmia, Xerostomia, Xerotrachea.