IgG4-Related Retroperitoneal Fibrosis: A Rare Association With Riedel's Thyroiditis.

Idiopathic retroperitoneal fibrosis is a rare fibro-inflammatory disease that can be associated with other IgG4-related diseases (IgG4-RDs). It is exceedingly uncommon to encounter this condition in a patient with Riedel's thyroiditis (RT), another disease in the IgG4-RD family. We present the case of a 53-year-old man with a history of RT who presented for severe localized lower abdominal and suprapubic pain due to obstructive uropathy from extensive retroperitoneal fibrosis. The biopsy of the mass demonstrated fibro-inflammatory tissue, and its immunohistochemistry was notable for IgG4-positive plasma cells. This case highlights the challenge associated with the diagnosis and management of this rare manifestation of IgG4-RD. In a patient with a history of any form of IgG4-RDs, providers should be vigilant for any signs or symptoms that suggest the development of fibrosis in other organs.

Is GH nadir during OGTT a reliable test for diagnosis of acromegaly in patients with abnormal glucose metabolism?

PURPOSE: The growth hormone (GH) nadir during oral glucose tolerance test (OGTT) is the gold standard diagnostic test for acromegaly. The utility of OGTT-GH suppression test in patients with abnormal glucose metabolism (AGM) has not been well established. In this study, we compared the GH nadir during OGTT in patients evaluated for acromegaly in the presence and absence of AGM. METHODS: This is a retrospective cohort study of patients with acromegaly (G1, n = 40) and a group in whom acromegaly was not confirmed (G2, n = 53) who had OGTT-GH suppression test during 2000-2012, using a monoclonal GH immunoenzymatic assay. The patients were categorized as having normal glucose metabolism (NGM) or AGM. GH nadir during OGTT in each group were compared. RESULTS: In G1 and G2, 17 and 19 patients had AGM, respectively. Among 17 patients with diabetes, median HbA1C was 7% (range 5.7-9.6%). All except one patient had HbA1C< 8%. There was no difference in the GH nadir in patients with or without AGM within G1 (p = 0.15) and G2 (p = 0.43). All G1 patients with AGM had GH nadir > 0.4 µg/L. Four G1 patients with NGM had GH nadir<0.4 µg/L. All G2 patients had GH nadir < 0.4 µg/L, except one with NGM and GH nadir of 0.4 µg/L. CONCLUSION: Using highly sensitive GH assay, a GH nadir ≥ 0.4 µg/L during the OGTT-GH suppression test may be used for diagnosis of acromegaly in patients with AGM in the absence of poorly controlled diabetes.

Iodine deficiency: Clinical implications.

Iodine is crucial for thyroid hormone synthesis and fetal neurodevelopment. Major dietary sources of iodine in the United States are dairy products and iodized salt. Potential consequences of iodine deficiency are goiter, hypothyroidism, cretinism, and impaired cognitive development. Although iodine status in the United States is considered sufficient at the population level, intake varies widely across the population, and the percentage of women of childbearing age with iodine deficiency is increasing. Physicians should be aware of the risks of iodine deficiency and the indications for iodine supplementation, especially in women who are pregnant or lactating.

The Effects of Temperature and Relative Humidity on Point-of-Care Glucose Measurements in Hospital Practice in a Tropical Clinical Setting.

BACKGROUND: Hospitals in tropical countries experience conditions that exceed manufacturer temperature and humidity limits for point-of-care (POC) glucose reagents. Our goal was to assess the effects of out-of-limits storage temperature, operating temperature, and operating humidity on POC glucose measurement reliability. METHODS: Quality control measurements were performed monthly using glucose test strips stored under controlled conditions and in inpatient wards under ambient conditions. Glucose test strips were evaluated in groups organized by operating temperatures of 24-25 (group 1), 28-29 (group 2), and 33-34°C (group 3), and relative humidity (RH) of ≤70 (group A), ~80 (group B), and ~90% (group C). RESULTS: Glucose results for different storage conditions were inconsistent. Measurements at higher operating temperatures had lower values with mean differences of -2.4 (P < .001) and -36.5 (P < .001) mg/dL (28-29 vs 24-25°C), and -3.6 (P < .001) and -37.4 (P < .001) mg/dL (33-34 vs 24-25°C) for low and high control levels, respectively. Measurements at higher RH had lower values with mean differences of -4.0 (P < .001) and -13.2 (P < .001) mg/dL (~80 vs ≤70% RH), and -5.8 (P < .001) and -16.6 (P < .001) mg/dL (~90 vs ≤70% RH) for low and high levels, respectively. CONCLUSIONS: High temperature and high RH decreased glucose concentrations for the POC oxidase-based system we evaluated. We recommend that individual hospitals perform stress testing, then determine if maximum absolute differences, which represent highest risk for patients, are clinically significant for decision making by using error grid analysis.

Significant hypercortisolism during fractionated radiotherapy in a patient with a large corticotroph adenoma: a case report and literature review.

OBJECTIVE: We describe a patient with a large, invasive corticotroph adenoma who developed severe hypercortisolism shortly after starting fractionated radiotherapy. METHODS: We reviewed the patient's clinical course, along with relevant literature for similar reported cases. RESULTS: A 29-year-old man was referred for radiotherapy for a residual and recurrent, invasive corticotroph adenoma. Prior to radiotherapy, he had a normal urine free cortisol (UFC) level of 44.7 µg/24 hours, with minimal symptoms. Within 2 weeks of radiotherapy, he developed hypertension, ankle edema, and hypokalemia (potassium level, 2.8 mEq/L), with a markedly elevated UFC level of 9,203 µg/24 hours. His UFC gradually decreased and normalized by the end of radiotherapy. One month later, the patient became adrenal insufficient, with a nondetectable 24-hour UFC. His adrenal function slowly recovered in 3 months. We are aware of only one previous case report of clinically significant hypercortisolism following radiotherapy in Cushing disease. CONCLUSION: Radiotherapy may result in acute severe hypercortisolism in patients with a large corticotroph adenoma. This uncommon, but clinically significant, acute adverse effect of radiotherapy suggests that clinical observation and biochemical monitoring during or soon after radiotherapy may be indicated.