False hyperthyroidism caused by interference in immunoassays

Hyperthyroidism caused by a pituitary adenoma.

hyperthyroidism that was difficult to control despite methimazole therapy. Her symptoms included headaches, palpitations, left-eye pain and frequent loose bowel movements. At referral, her serum thyroidstimulating hormone (TSH) level was 10.45 (normal 0.35–5.5) mIU/L and her free thyroxine (FT4) level was 17.8 (normal 11.5–22.7) pmol/L. A two-week methimazole withdrawal was attempted, resulting...

Hyperthyroidism caused by acquired immune deficiency syndrome.

BACKGROUND Acquired immune deficiency syndrome (AIDS) is an immune deficiency disease. The etiology of hyperthyroidism, which can also be immune-related, is usually divided into six classical categories, including hypophyseal, hypothalamic, thyroid, neoplastic, autoimmune and inflammatory hyperthyroidism. Hyperthyroidism is a rare complication of highly active antimicrobial therapy (HAART) for ...

Screening for interference in immunoassays.

Screening for interference in immunoassays.

BACKGROUND The presence of interfering substances in patient samples submitted for immunoassay cannot be reliably anticipated. We therefore evaluated three interference screening techniques and estimated the prevalence of interfering substances as defined by positive outcomes with these protocols. METHODS We evaluated 160 samples for the presence of substances that may interfere with four imm...

Approaches to minimizing interference by cross-reacting molecules in immunoassays.

Here we review techniques useful in eliminating or reducing interferences caused by molecules that cross-react in immunoassays. The biochemical rationale for using these techniques is discussed. Examples are taken from recent studies aimed at reducing interferences caused by endogenous molecules such as digoxin-like immunoreactive factors or steroid hormones. In this context the role of protein...