INTRODUCTIONIn a patient with hyperthyroidism, the detection of elevated thyroid hormone concentration with measurable thyroid-stimulating hormone (TSH) value poses considerable diagnostic difficulties.

CLINICAL PICTUREThis 38-year-old lady presented with clinical features of thyrotoxicosis. Her serum free thyroxine concentrations were unequivocally elevated [45 to 82 pmol/L (reference interval, 10 to 20 pmol/L)] but the serum TSH values were persistently within the reference interval [0.49 to 2.48 mIU/L (reference interval, 0.45 to 4.5 mIU/L)].

TREATMENTInvestigations excluded a TSH-secreting pituitary adenoma and a thyroid hormone resistance state and confirmed false elevation in serum TSH concentration due to assay interference from heterophile antibodies. The patient was treated with carbimazole for 18 months.

OUTCOMEThe heterophile antibody-mediated assay interference disappeared 10 months following the initiation of treatment with carbimazole, but returned when the patient relapsed. It disappeared again 2 months after the initiation of treatment.

CONCLUSIONSClinicians should be aware of the potential for interference in immunoassays, and suspect it whenever the test results seem inappropriate to the patient's clinical state. Misinterpretation of test values, arising as a result of assay interference, may lead to misdiagnosis, unnecessary and at times expensive investigations, delay in initiation of treatment and worst of all, the initiation of inappropriate treatment.

Adenoma ; diagnosis ; Adult ; Antibodies, Heterophile ; analysis ; immunology ; Diagnostic Errors ; Female ; Graves Disease ; diagnosis ; Humans ; Immunoassay ; Pituitary Neoplasms ; diagnosis ; Thyrotoxicosis ; blood ; diagnosis ; immunology ; Thyrotropin ; blood ; Thyroxine ; blood

Background/Aims: Insomnia is common in people with chronic medical conditions, such as inflammatory bowel disease (IBD), and is readily treatable through cognitive behavioral therapy for insomnia. This study aimed to describe the associations with insomnia in people with IBD and its relationship to IBD-related disability. Methods: An online questionnaire was administered through 3 tertiary IBD centers, social media, and Crohn’s Colitis Australia. The questionnaire included the Insomnia Severity Index (ISI), a validated assessment of insomnia. Measures of anxiety, depression, physical activity, and disability were also included. IBD activity was assessed using validated patient reported scores. A multivariate model was constructed for clinically significant insomnia and ISI scores. Subpopulations of Crohn’s disease and ulcerative colitis were considered. Results: In a cohort of 670 respondents the median age was 41 years (range, 32–70 years), with the majority female (78.4%), the majority had Crohn’s disease (57.3%). Increasingly severe disability was associated with worse insomnia score. Clinically significant insomnia was associated with clinically active IBD, abdominal pain, anxiety, and depression, in a multivariate model. In an ulcerative colitis population, Simple Clinical Colitis Activity Index components of general well-being and urgency were associated with worse ISI score in a model including depression and anxiety. In those with Crohn’s disease, the multivariate model included Harvey Bradshaw Index score in addition to depression and anxiety. Conclusions Insomnia is common in people with IBD and is associated with increased disability. Abdominal pain and mental health conditions should prompt consideration for screening for insomnia and referral for cognitive behavioral therapy for insomnia.