Evaluation of the (1-24) adrenocorticotropin stimulation test for the diagnosis of primary aldosteronism.

OBJECTIVE: The purpose of this study was to investigate the diagnostic power of the adrenocorticotropin (ACTH) stimulation test in patients with primary aldosteronism (PA) and those with aldosterone-producing adenoma (APA). DESIGN: This study was based on a retrospective database analysis. SUBJECTS AND METHODS: We assessed 158 hypertensive patients with a high plasma aldosterone-to-renin ratio (ARR) including 97 with at least one positive confirmatory test result who did not undergo surgery and comprised a "possible PA" group, 19 with negative results in all tests who were the "non-PA" group, and 41 diagnosed with APA following surgery who were the APA group. The "confirmed PA group" included APA patients and patients from the possible PA group showing both high ARR and hypokalemia. One case was diagnosed as a metastasis. RESULTS: Receiver-operating characteristic (ROC) analysis showed that the diagnostic accuracy of ACTH test was not very effective in differentiating between APA patients and possible PA and non-PA patients. The optimal cut-off value of maximal plasma aldosterone concentration for differentiating between patient in the confirmed PA group and other patients showed moderate accuracy. CONCLUSIONS: The ACTH test may not be useful as a screening or confirmatory test, but the test may be useful for differentiating between patients with confirmed PA and the rest of the cohort. The positive finding of the ACTH test may at least support a higher likelihood of lateralizing on adrenal venous sampling.

Quantitative RT-PCR evaluation of a rapid influenza antigen test for efficient diagnosis of influenza virus infection.

Influenza virus infection is diagnosed in most cases using a rapid influenza antigen diagnostic test (RIDT). However, false-negative results are a major concern. By contrast, the nucleic acid amplification test offers high sensitivity and therefore can aid the interpretation of negative RIDT results. In this study, influenza viral loads were quantified with quantitative reverse transcription-polymerase chain reaction (qRT-PCR) using viral suspensions left over after RIDT, and the performance of both methods was evaluated. qRT-PCR detected as few as 10(3)copies/mL of influenza viruses A and B, whereas RIDT showed negative results for viral loads less than 10(7) and 10(5)copies/mL of influenza viruses A and B, respectively. These results indicate that small quantities of the virus that cause false-negative RIDT results can be detected efficiently with qRT-PCR follow-up. In addition, influenza A virus subtype was determined using qRT-PCR.

Relevance of molecular tests for HTLV-1 infection as confirmatory tests after the first sero-screening.

The diagnosis of human T-cell leukemia virus type-1 (HTLV-1) infection has been widely examined by serologics. In the first screening tests, serological false negative and positive samples have been reduced thanks to advances in assay techniques that apply new emission agents and sensors. On the other hand, western blot (WB) remains problematic. For example, WB analysis yields many samples equivalent to antibody positive ones. To reduce the need for WB, an alternative testing strategy is required to detect HTLV-1 infection. Polymerase chain reaction (PCR) for the HTLV-1 provirus has recently been recommended for a final diagnosis of infection. However, although PCR is thought to be one element, the validation of detection performance for HTLV-1 infection between serological and molecular testing is not always clear. Thus, this study aimed to evaluate the accuracy and test the validity of an improved methodology for serological detection of HTLV-infection, as well as that of PCR. In conclusion, the high values of kappa-statistics are expected to deliver high quality in chemiluminescent enzyme immunoassay (or chemiluminescent immunoassay), while the problems with WB assays remain to be elucidated. As an alternative to WB, a combination of real-time qPCR and nested PCR is proposed as a suitable confirmatory test.

An adult case of 22q11.2 deletion syndrome diagnosed in a 36-year-old woman with hypocalcemia caused by hypoparathyroidism and Hashimoto's thyroiditis.

22q11.2 Deletion syndrome is recognized to be a major cause of congenital hypoparathyroidism, and affected patients exhibit a range of autoimmune characteristics. The syndrome becomes apparent in early childhood and is rarely diagnosed in adulthood. This report describes an adult case of 22q11.2 deletion syndrome first diagnosed in a 36-year-old woman with hypocalcemia caused by hypoparathyroidism and Hashimoto's thyroiditis. It is important to diagnose 22q11.2 deletion syndrome in adults because such patients are still at high risk for developing treatable diseases, such as hypocalcemia and autoimmune diseases.

Exaggerated response of adrenocorticotropic hormone to growth hormone-releasing peptide-2 test in Cushing's disease. Case report.

A 47-year-old woman presented with a pituitary microadenoma manifesting as typical Cushing's syndrome. The diagnosis was Cushing's disease based on the endocrinological findings. Plasma adrenocorticotropic hormone (ACTH) levels were greatly increased from 66 pg/ml to 2490 pg/ml (about 38-fold) in response to the administration of 100 microg human growth hormone-releasing peptide (GHRP)-2. GHRP receptor type 1a messenger ribonucleic acid was detected in the tumor. Therefore, GHRP-2 may stimulate ACTH via the GHRP receptor type 1a in pituitary ACTH-producing tumor. The GHRP-2 test, currently clinically available in Japan, may be a useful diagnostic tool for Cushing's disease.

Deficiency of growth hormone in an adult man case of idiopathic adrenocorticotropin deficiency.

Growth hormone (GH) deficiency is transient in most cases of adrenocorticotropin (ACTH) deficiency, while deficiency of both selective ACTH and GH in adults, as in the present case, is rare among hypopituitarism cases. In this patient, one year after hydrocortisone replacement for ACTH deficiency, data on GH secretion by insulin tolerance test and GH-releasing peptide-2 injection showed a partial improvement, but still there was lack of an adequate response. We consider that the patient had the deficiency of both selective GH and ACTH. Therefore, careful monitoring of GH function after the glucocorticoid replacement is required in cases of ACTH deficiency.