Up-Regulation of the Receptor for Advanced Glycation End Products in the Skin Biopsy Specimens of Patients with Severe Diabetic Neuropathy

BACKGROUND AND PURPOSE: The receptor for advanced glycation end products (RAGE) may contribute to the development of diabetic neuropathy. To assess its relevance in humans, this study examined the expression of RAGE in the skin biopsy samples of patients with diabetes mellitus, and investigated its correlation with intraepidermal nerve-fiber density (IENFD) and clinical measures of neuropathy severity. METHODS: Forty-four patients who either had type 2 diabetes or were prediabetes underwent clinical evaluation and a 3-mm skin punch biopsy. The clinical severity of their neuropathy was assessed using the Michigan Diabetic Neuropathy Score. IENFD was measured along with immunohistochemical staining for RAGE in 29 skin biopsy samples. The expression of RAGE was also quantified by real-time reverse-transcription PCR in the remaining 15 patients. RESULTS: RAGE was localized mostly in the dermal and subcutaneous vascular endothelia. The staining was more intense in patients with a lower IENFD (p=0.004). The quantity of RAGE mRNA was significantly higher in patients with severe neuropathy than in those with no or mild neuropathy (p=0.003). The up-regulation of RAGE was related to dyslipidemia and diabetic nephropathy. There was a trend toward decreased sural nerve action-potential amplitude and slowed peroneal motor-nerve conduction with increasing RAGE expression. CONCLUSIONS: The findings of this study demonstrate up-regulation of RAGE in skin biopsy samples from patients with diabetic neuropathy, supporting a pathogenic role of RAGE in the development of diabetic neuropathy.

A Case of Protein-losing Enteropathy with an Abnormal Cortisol Response to ACTH Stimulation / 대한내분비학회지

We hereby report a case of a 62-year-old male patient who was misdiagnosed with adrenal insufficiency during the course of protein-losing enteropathy caused by superior mesenteric arterial thrombosis. The patient was suspected to have adrenal insufficiency due to hyponatremia and severe weakness. The cortisol responses to the initial challenge of 250microgram ACTH were inadequate (maximum serum cortisol level after ACTH challenge was 10.9microgram/dL), while the serum albumin concentration was 1.9g/dL. Subsequently, intravenous steroid therapy was given to the patient. However, after bowel resection, the serum albumin level increased to 3.4g/dL and the cortisol response to the follow-up rapid ACTH stimulation was completely normal. Accordingly, we discontinued steroid replacement and discharged the patient without any problem. In conclusion, measuring total serum cortisol in a patient with hypo-pro-teinemia may lead to misdiagnosis of adrenal insufficiency. In such cases, caution should be exercised in interpreting the results in terms of total serum cortisol level or measurement of serum free cortisol levels should be considered.

A Case of Coexistence of Malignant Lymphoma and Papillary Carcinoma in Thyroid / 대한혈액학회지

A 65 year-old female visited because of neck mass. Tumors were found in thyroid, neck nodes, lung parenchyma, liver, kidney and bone. Biopsy of neck node revealed malignant lymphoma (diffuse large B cell lineage) and metastatic papillary thyroid carcinoma simultaneously. Her thyroid function was normal. She was treated with chemotherapy targeting malignant lymphoma initially, and achieved near complete remission. Additional biopsy of neck node after first chemotherapy revealed no papillary carcinoma. To our knowledge, this is the first report of malignant lymphoma and papillary carcinoma simultaneously involving thyroid gland in Korea.