Sjogren syndrome: Pathology review

On your rounds, you see a 55-year-old female named Patricia who presents with fatigue, dry skin, and red eyes. She mentions that she's had a recurrent sensation of sand in her eyes and dry mouth every day for the past three months. She also mentioned that when it’s cold outside, the tips of her fingers turn white and hurt. On examination, there are signs of tooth decay and purpura on both lower extremities. Sialometry was performed, which detected salivary hypofunction.

Ok, so Patricia’s clinical picture is suggestive of Sjogren syndrome. Now, Sjogren syndrome is an autoimmune disorder that mostly affects middle-aged females. The high yield concept here is that the immune system attacks various exocrine glands, especially salivary and lacrimal glands. If Sjogren syndrome is primary or occurs alone, it’s called sicca syndrome. Alternatively, it can be secondary when it is accompanied by other autoimmune diseases like lupus, rheumatoid arthritis, and scleroderma. Now, the exact cause of Sjogren syndrome is unknown, but both genetic and environmental factors are involved.

In Sjogren syndrome, some helper T-cells perceive nuclear components that leak out of dead or damaged cells in the body as antigens. These T-cells become active and proliferate and then activate B-cells which start producing anti-nuclear antibodies, or ANAs, against the nuclear antigens. A high yield fact to remember is that the two types of ANA formed in Sjogren syndrome are anti-SSA/RO and anti-SSB/LA antibodies, which are formed against ribonucleoproteins SS-A and SS-B. Next, both T-cells and antibodies enter the circulation and reach the exocrine glands, where activated T-cells secrete cytokines to recruit even more immune cells. This results in a lymphocytic infiltration of the exocrine glands, which ends up damaging the exocrine gland tissue. Eventually, the secreted cytokines also activate fibroblasts, which produce fibrous tissue that replaces the damaged tissue. The end result is a loss of secretory cells in the glands.