Surgical remission of Cushing’s Disease linked to autoimmune disease

The incidence of autoimmune disease is higher among patients who achieved surgical remission of Cushing’s disease (CD) than age- and sex-matched individuals with nonfunctioning pituitary adenomas (NFPAs), results of a study have shown.

A potential risk factor is a history of autoimmune disease in the family, while adrenal insufficiency appears to be a trigger.

CD patients had a higher cumulative incidence of new-onset autoimmune disease (hazard ratio, 7.80, 95 percent confidence interval [CI], 2.88‒21.10) at 3 years after surgery (10.4 percent, 95 percent CI, 5.7‒15.1) than those with NFPAs (1.6 percent, 95 percent CI, 0‒4.6).

Patients with CD also displayed a higher prevalence of postoperative adrenal insufficiency (93.8 percent vs 16.5 percent) and lower levels of postoperative nadir serum cortisol (63.8 vs 282.3 nmol/L) than those with NFPAs.

Notably, CD patients who developed autoimmune disease showed a lower preoperative 24-hour urine free cortisol (UFC) ratio (2.7 vs 6.3) and a higher prevalence of family history of autoimmune disease (41.2 percent vs 20.9 percent) than CD patients without autoimmune disease.

This retrospective matched cohort analysis included CD patients with surgical remission and surgically treated NFPA from an academic medical centre or a pituitary centre.

The investigators measured the cumulative incidence of new-onset autoimmune disease at 3 years after surgery. They also assessed hypercortisolemia, including late-night salivary cortisol levels, 24-hour UFC ratio (UFC value divided by the upper limit of the normal range for the assay), and dexamethasone suppression tests.

The study was limited by the small sample of patients with autoimmune disease.