POSITIVE TEST FOR ANTITHYROGLOBULIN ANTIBODIES DUE TO ADMINISTRATION OF IMMUNOGLOBULIN REPLACEMENT THERAPY IN A PATIENT WITH THYROID CANCER.

OBJECTIVE: Thyroglobulin (Tg) is used as a tumor marker to monitor differentiated thyroid cancer progression and recurrence. However, Tg measured by standard immunoassay (IMA) is not a reliable marker in the presence of anti-Tg antibodies (TgAbs) due to interference that may result in either false-positive or false-negative results. TgAbs levels can be high due to thyroid cancer and also exogenous immunoglobulin (Ig) administration, thus making it difficult to identify differentiated thyroid cancer recurrence. METHODS: We present an example of elevated TgAbs due to subcutaneous Ig (SCIg) administration in a patient with thyroid cancer. RESULTS: A 57-year-old male was diagnosed with stage I papillary thyroid cancer (PTC). His TgAbs were negative prior to the diagnosis of thyroid cancer and became positive after thyroidectomy and radioactive iodine administration. A detailed work-up including a whole body scan did not reveal recurrent disease. He had been diagnosed with common variable immune deficiency (CVID) and dermatomyositis at the age of 50 and was started on immunoglobulin (Ig) replacement therapy shortly after diagnosis. His Tg was negative when assessed with liquid chromatography-tandem mass spectrometry (LC-MS/MS). Therefore, elevated TgAb titers were attributed to concomitant SCIg treatment. We also demonstrated that SCIg treatment had TgAb activity that was removed by protein A column treatment. Dilutions of SCIg medication also caused positive IgG serologies for cytomegalovirus and herpes simplex, measles, mumps, rubella, and varicella zoster viruses. CONCLUSION: An exogenous source of TgAbs from SCIg led to extensive imaging work-up to assess for PTC recurrence. LC-MS/MS is a conceptually attractive approach to overcome TgAb interference with Tg IMA measurement.

A rare case of double parathyroid lipoadenoma with hyperparathyroidism.

A rare case of double lipoadenomas of parathyroid glands with hyperparathyroidism is described. A 56-year-old woman was referred for management of diabetes. Work up revealed: serum Calcium (Ca) =11.9 mg/dl, glomerular filtration rate (GFR) = 103 ml/min/m2, parathyroid hormone (PTH) = 60 pg/ml, Phosphorus = 3.0 mg/dl, 25 hydroxy vitamin D (25 OH D) =16.5 ng/ml, 24 h urine Calcium =179 mg/day. Parathyroid sestamibi scan showed increased activity in the left thyroid and right thyroid lobe. Single photon emission computed tomography demonstrated uptake in inferior left and right thyroid lobes. Her serum calcium following successful bilateral parathyroidectomy was 9.3 mg/dl. Pathology showed double parathyroid lipoadenomas. After surgery, her serum Calcium and PTH normalized to 9.8 mg/dl and 32 pg/ml respectively. Lipoadenoma has been described as a very rare lesion of the parathyroid gland and is most commonly non-functional. PubMed search failed to reveal any case of hyperparathyroidism due to double parathyroid lipoadenomas.

Increased bone alkaline phosphatase and isolated subcortical bone uptake of technetium-99m hydroxymethylene diphosphonate in the lower extremities in a patient with Graves' disease: a distinctly unusual variant of Graves' acropachy.

BACKGROUND: Thyroid acropachy is an extreme manifestation of autoimmune thyroid disease characterized by soft tissue swelling and periosteal bone changes, usually occurring in the fingers, toes, and lower extremities. Here, a patient with a distinctly unusual variant of thyroid acropachy is presented. PATIENT FINDINGS: The patient was a 48-year-old woman with Graves' disease and mild ophthalmopathy, who was euthyroid after treatment with Methimazole. Because of a persistently elevated serum alkaline phosphatase (ALP) with elevated bone fraction, a bone scan was performed. This showed increased uptake in the subcortical areas of the lower extremity bones. On questioning, she admitted to mild pain in her lower extremities. She had no other features of thyroid acropachy. Secondary causes of increased ALP, such as cancer, liver disease, and vitamin D deficiency, were excluded by appropriate tests. Therefore, and in view of the patient's underlying Graves' disease, a diagnosis of thyroid acropachy was made. SUMMARY AND CONCLUSIONS: Periosteal reaction in the long bones of the lower extremities is unusual in thyroid acropachy, and when it occurs, it is more likely to be associated with overt pain or prominent extrathyroidal manifestations of Graves' disease. This patient very likely had a variant of thyroid acropachy. This variant may be underreported because of its generally asymptomatic nature.

Suppression of thyrotropin by morphine in a severely stressed patient.

Opiates suppress TSH in experimental animals but are reported to increase TSH in human subjects. We describe a patient in severe pain treated with morphine, whose previously normal TSH fell to a level usually associated with hyperthyroidism. After returning to a normal concentration, TSH again decreased with morphine administration. This suggests that, in contrast to the stimulation of TSH secretion that has been reported in unstressed experimental subjects, morphine can inhibit TSH secretion during stress in man as it does in experimental animals. This observation is consistent with the known sensitization of opiate receptors by stress. Consideration should be given to the possibility that severe suppression of TSH by opiates in stressed patients may induce clinically significant central hypothyroidism.

Abrogation of oxidative stress improves insulin sensitivity in the Ren-2 rat model of tissue angiotensin II overexpression.

To evaluate the role of renin-angiotensin system (RAS)-mediated oxidative stress in insulin resistance (IR), we compared the effects of the angiotensin II (ANG II) receptor blocker (ARB) valsartan and a superoxide dismutase (SOD) mimetic, tempol, on whole body glucose tolerance and soleus muscle insulin-stimulated glucose uptake in transgenic hypertensive TG(mREN-2)27 (Ren-2) rats. Ren-2 rats and Sprague-Dawley (SD) controls were given valsartan (30 mg/kg) or tempol (1 mmol/l) in their drinking water for 21 days. IR was measured by glucose tolerance testing (1 g/kg glucose ip). IR index (AUC(glucose) x AUC(insulin)) was significantly higher in the Ren-2 animals compared with SD controls (30.5 +/- 7.0 x 10(6) arbitrary units in Ren-2 vs. 10.2 +/- 2.4 x 10(6) in SD, P < 0.01). Both valsartan and tempol treatment normalized Ren-2 IR index. Compared with SD controls (100%), there was a significant increase in superoxide anion production (measured by lucigenin-enhanced chemiluminescence) in soleus muscles of Ren-2 rats (133 +/- 15%). However, superoxide production was reduced in both valsartan- and tempol-treated (85 +/- 22% and 59 +/- 12%, respectively) Ren-2 rats. Insulin (INS)-mediated 2-deoxyglucose (2-DG) uptake (%SD basal levels) was substantially lower in Ren-2 rat soleus muscle compared with SD (Ren-2 + INS = 110 +/- 3% vs. SD + INS = 206 +/- 12%, P < 0.05). However, Ren-2 rats treated with valsartan or tempol exhibited a significant increase in insulin-mediated 2-DG uptake compared with untreated transgenic animals. Improvements in skeletal muscle insulin-dependent glucose uptake and whole body IR in rats overexpressing ANG II by ARB or SOD mimetic indicate that oxidative stress plays an important role in ANG II-mediated insulin resistance.