An automated solid-phase 17 alpha-hydroxyprogesterone ELISA method using a microtitre plate

Three-year follow up of adrenal incidentalomas in a New Zealand centre

BACKGROUND

The international guidelines for management of adrenal incidentalomas (AI) are becoming more conservative. These changes are based on the growing body of evidence suggesting that non-functioning adenomas have a low likelihood of becoming functional or malignant over time.

AIMS

To follow up at least 100 patients for 3 years who were originally found to have benign adrenal adenomas which were non-functional or had subclinical Cushing syndrome (SCS).

METHODS

This study prospectively evaluated consecutive patients aged 18 years or older with benign adrenal incidentalomas (AI), not treated with adrenalectomy, which were non-functioning or had SCS. The initial and follow-up evaluation, including clinical assessment, hormonal investigations and imaging were coordinated via a standardised nurse-led AI clinic.

RESULTS

Of 233 patients referred to the AI clinic, 101 patients met the inclusion criteria and completed 3-year follow up. Most of those excluded were due to incomplete initial or follow-up evaluation or were not true AI. Most AI either remained stable or decreased in size on repeat imaging, while 5% of patients had AI enlargement of >5 mm diameter. No patient developed features suggesting adrenal carcinoma. Ninety-two patients had an initial diagnosis of non-functioning adenoma and nine patients had SCS. After 3 years (range 2.9-4.7 years), five of the nine patients with SCS showed normalisation of cortisol parameters (44%), and five of the 92 non-functional AI patients developed SCS (5%).

CONCLUSION

After 3 years of follow up, approximately half of patients with SCS normalised, while 5% of patients with initially non-functioning adenomas developed biochemical evidence of SCS. This study found a low likelihood of progressive hormonal excess with no evidence of malignancy developing on follow-up evaluation, providing support for the shift towards the more conservative approach to management of AI recommended in recent guidelines.

Characteristics of adrenal incidentalomas in a New Zealand centre

BACKGROUND

Management of adrenal incidentalomas (AI) is becoming more conservative, based on international data showing a low incidence of functional or malignant lesions. The clinical characteristics of AI in New Zealand are unknown. Therefore, whether the AI guidelines apply to the New Zealand population is also unknown.

AIMS

To investigate the clinical characteristics of patients with AI presenting to a tertiary-care centre in New Zealand.

METHOD

This study prospectively evaluated consecutive patients aged 18 or older with AI, 1 cm or larger, diagnosed in Canterbury, New Zealand. A standardised nurse-led dedicated AI clinic was used, including clinical assessment, hormonal evaluation and imaging.

RESULTS

From January 2010 to April 2016, 306 patients were referred to the AI clinic, 228 met the inclusion criteria. Most of those excluded were not true AI, due to imaging performed for known or suspected non-adrenal malignancy. The most common reason for imaging was abdominal pain (46%). Most cases were benign (96.5%) and 88.6% of all cases were non-functional. Of the functioning tumours (26 patients), 18 had subclinical Cushing syndrome, four had late-onset congenital adrenal hyperplasia, two had phaeochromocytoma and one had primary hyperaldosteronism. Three patients had primary adrenal cancer, one of whom was secreting excess cortisol. One adrenal metastasis was diagnosed.

CONCLUSION

This study found a similar prevalence of functional and malignant AI as international centres, although mild cortisol excess and primary aldosteronism may be under-represented. Therefore, the conservative approach to management of AI recommended in current guidelines is likely to be applicable to New Zealand population.

Effect ofGinkgo bilobaExtract on Plasma Steroid Concentrations in Healthy Volunteers: A Pilot Study

STUDY OBJECTIVE

To determine if a standardized ginkgo supplement significantly alters concentrations of circulating androgenic steroids in humans.

DESIGN

Open-label, fixed-treatment order, crossover study.

SETTING

University general clinical research center.

SUBJECTS

Eleven healthy volunteers (six men, five women).

INTERVENTION

Volunteers received ginkgo biloba 240 mg/day for 14 days.

MEASUREMENTS AND MAIN RESULTS

Plasma concentrations of cortisol, 11-deoxycortisol, 17alpha-hydroxyprogesterone, testosterone, dihydrotestosterone, dehydroepiandrosterone sulfate, sex hormone-binding globulin, androstenedione, and free testosterone, as well as free androgen index and combined concentrations of androsterone sulfate and epiandrosterone sulfate, were analyzed in all subjects before and after their 14-day course of ginkgo biloba. Ginkgo biloba did not significantly alter endogenous steroid levels compared with baseline values (p < 0.05).

CONCLUSION

A 14-day oral administration of a widely used, standardized ginkgo extract at a generally advocated dosage of 240 mg/day did not significantly alter concentrations of major circulating steroids in men and women.

A competitive enzyme-linked immunosorbent assay: applications in the assay of peptides, steroids, and cyclic nucleotides

Indirect competitive enzyme-linked immunosorbent assays (ELISAs) that can be used to quantify several types of small, bioactive molecules, including peptides, steroids, and cyclic nucleotides, are described. The assays require no special expertise to perform, and the sensitivities are very high, equally or exceeding what is commonly achieved in radioimmunoassay (RIA). The molecule to be assayed or a synthetic derivative is coupled to a protein carrier (= conjugate). The conjugate is adsorbed to the wells of a microtiter plate where it is bound by antibody in inverse proportion to free hapten in a sample or standard. Bound antibody is then quantified with enzyme-labeled anti-immunoglobulin and appropriate substrate. The assay of peptides is illustrated for the sulfated cholecystokinin octapeptide, in which an ED50 of 20 fmol (2 x 10(-10) M in 100 microliters assay volume) is attained. The ED50's and slopes of the dose-response curves in the steroid and cyclic nucleotide ELISAs are compared with those parameters obtained earlier by RIA using the same antisera. This comparison indicates that a steroid, ecdysone, can be quantified with no apparent participation of the bridging group of the conjugate in the competitive assay. Furthermore, the ED50's in the ecdysone assays (ecdysone 2 beta, 3 beta, 14 alpha, 22R, 25-pentahydroxy-5 beta-cholest-7-en-6-one, 7.7 fmol; 20-hydroxyecdysone, 16 fmol) are 19- to 38-fold lower for ELISA than for RIA. In the cyclic nucleotide assay, the bridge of a cAMP conjugate (homologous with the bridge of the immunogen) decreases the slope of the dose-response curve. This effect is minimized by the use of short incubations with anti-cAMP.(ABSTRACT TRUNCATED AT 250 WORDS)