Rare coincidence: Macro-thyroid-stimulating hormone and multiple manufacturer-specific interferences in thyroid hormone immunoassays.

Immunoassays are widely used for laboratory assessment of endocrine functions including thyroid hormones. While usually adequate for patient evaluation, they are known to potentially suffer from interference from a variety of factors. We report the case of a 44 year-old male patient without clinical symptoms of thyroid disease who presented for specialist evaluation after pathological thyroid function tests prompted a transferal by his primary care practitioner. Thyroid function tests showed discrepant results across immunoassays and platforms of different manufacturers. Polyethylene glycol precipitation prompted the diagnosis of macro-thyroid-stimulating hormone, while heterophilic and non-specific antibody blocking reagents proved ineffective in eliminating the interference in thyroid-stimulating hormone, free triiodothyronine and free thyroxine measurements. Further assessment ruled out a diagnosis of familial dysalbuminemic hyperthyroxinemia, leaving an exclusion diagnosis of manufacturer-specific interference in free triiodothyronine and free thyroxine assays due to unknown factors. Both clinicians and laboratory specialists must be aware of potential interference in immunoassays which otherwise might be misleading, potentially triggering unnecessary (invasive) follow-up procedures or therapeutic interventions. Close communication is required for successful troubleshooting. To our knowledge, no other case of both macro-thyroid-stimulating hormone and manufacturer-specific interference in a single patient has been documented thus far.

Non-functioning pituitary macroadenomas: Benefit from early growth hormone substitution after surgery.

PURPOSE: Data suggests that substitution of GH in GH-deficient patients may improve quality-of-life and reduce insufficiency-associated-symptoms. Unlike in corticotroph, thyreotroph, or gonadotroph-insufficiency, GH-substitution is usually not started within the first 6-12months after surgery. We aimed to investigate the effect of early-GH-substitution on body-composition, metabolic and pituitary-laboratory-tests, and quality-of-life. METHODS: Data was reviewed from 21 adult-patients who were diagnosed with insufficiency of GH-axis using insulin-hypoglycemia-test. We retrospectively assessed body-composition, metabolic and pituitary-laboratory-tests and quality-of-life for a period of 52-weeks after pituitary-surgery in patients with early GH-substitution (= treated-group, 11-patients) and no GH-substitution (= untreated group, 10-patients). RESULTS: Follow-up-IGF-I-levels of the treated-group stayed within the normal range and differed significantly from the untreated-group. Bioelectrical-impedance-analysis showed a significant decrease of impedance, a significant increase of lean-body-mass and a significant difference in health status in the treated group (p<0.05). Average increase in HDL-level was 2.1mg/dl in the untreated compared to an average decrease of 0.2mg/dl in the treated-group. Lp(a)-levels were reduced by 4.1mg/dl in the treated and by 2.7mg/dl in the untreated-group. Both groups showed an initial-mean-life-satisfaction below average (-0.9 and -1.2). Within one year after surgery mean-health-status improved in both groups. The difference in health-status after 1-year compared to the health-status of the previous year was statistically different between both groups with a greater benefit in the treated-group. Finally there was a trend detectably pointing towards an improvement in pituitary-function (LH- and FSH-recovery) if GH was substituted. CONCLUSION: Early GH-substitution leads to a significant improvement in quality-of-life and body-composition after pituitary-surgery. It is possible that pituitary-function recovers more with early-GH-substitution.

Treatment with sibutramine prior to Roux-en-Y gastric bypass leads to an improvement of metabolic parameters and to a reduction of liver size and operative time.

BACKGROUND: Previous studies have shown that a preoperative weight loss is associated with better long-term outcome, fewer complications, and less time in the operating room in bariatric patients. However, preoperative weight loss is hard to achieve in many patients. METHODS: We, therefore, conducted a study in which 20 bariatric patients received 15 mg of the weight loss medication sibutramine prior to laparoscopic Roux-en-Y gastric bypass (RYGBP) while patients in the control group did not. It was our interest to find out if these patients had a benefit compared to a control group who did not receive medication. RESULTS: Whereas patients in the sibutramine group lost 4.8 kg within 6 weeks, patients in the control group gained 7.0 kg. Along with the change in weight, the size of the left liver lobe decreased in the sibutramine-treated patients and increased in the control group. Glutamic pyruvic transaminase as a parameter of liver function improved with reduction of liver size. Finally, time in the operating room was shorter for patients with preoperative weight loss due to sibutramine intake. CONCLUSIONS: Medical therapy with sibutramine in preparation for bariatric surgery can improve the health status of patients and lead to a reduction of liver size and operating time. It should be considered as an alternative or addition to dietary therapy or gastric balloon treatment in the preparation of patients expecting a RYGBP.