Autoantibodies in chronic idiopathic urticaria and nonurticarial systemic autoimmune disorders.

BACKGROUND: Chronic idiopathic urticaria (CU) has been associated with other autoimmune diseases and basophil-activating autoantibodies to FcεRI or IgE. It is unknown whether patients with systemicautoimmune diseases have a similar prevalence of these autoantibodies. OBJECTIVE: To compare the prevalences of basophil-activating autoantibodies (elevated CU Index) in patients with CU, rheumatoid arthritis (RA), and systemic lupus erythematosus (SLE). Clinical characteristics and laboratory studies were examined for an association with the CU Index. METHODS: Adult patients, 27 with CU, 27 with RA, and 26 with SLE, and 20 healthy controls were compared on the basis of the CU Index panel, anti-IgE, and antithyroid antibodies. RESULTS: The CU Index values were significantly higher in the CU group when compared with the RA group but not when compared with the SLE group. 33% of CU, 23% of SLE, 3.7% of RA, and 15% of controls had apositive CU Index. Elevated antithyroid antibody levels did not correlate with a positive CU Index in any of the groups. An elevated CU Index in the SLE group was not associated with age, sex, ethnicity, disease severity, or history of atopy. CONCLUSION: The CU Index values were elevated in patients with CU and SLE. The presence of these autoantibodies did not correlate with disease activity or presence of thyroid antibodies. Functional autoantibodies may not be specific for chronic idiopathic urticaria, and their role in nonurticarial systemic autoimmune diseases requires further investigation.

Use of fluorine-18-labelled deoxyglucose positron emission tomography with computed tomography to localize a paraganglioma in pregnancy.

A nine-weeks pregnant, 27-year-old female was admitted for hypertension with a blood pressure of 213/110 mm Hg, headaches, palpitations, and anxiety. There was no previous history of hypertension or pre-eclampsia. She had elevated urinary normetanephrine, plasma-free normetanephrine, and plasma-free metanephrine concentrations. Phenoxybenzamine and labetalol were initiated for presumed pheochromocytoma. At thirteen weeks of pregnancy, a noncontrast magnetic resonance imaging (MRI) of the abdomen failed to identify an adrenal or extra-adrenal mass. At 21-weeks gestation, an abdominal [18-F]-fluorodeoxyglucose positron emission tomography with computed tomography demonstrated an extra-adrenal lesion. The patient underwent a laparotomy during the second trimester with successful removal of a benign paraganglioma.