Commentary to the article: comparison of low and high dose corticotropin stimulation tests in patients with pituitary disease

Current Screening Strategies for the Diagnosis of Adrenal Insufficiency in Children

Adrenal insufficiency can arise from a primary adrenal disorder, secondary to adrenocorticotropic hormone deficiency, or by suppression of hypothalamic-pituitary-adrenal axis due to exogenous glucocorticoids. Diagnosis of adrenal insufficiency is usually delayed because the initial presentation is often subtle and nonspecific. Clinician awareness and recognition is crucial for timely diagnosis to avoid adrenal crisis. Current screening strategies for the diagnosis of adrenal insufficiency in children in various clinical situations are discussed in this review.

Pediatric Adrenal Insufficiency: Diagnosis, Management, and New Therapies

Adrenal insufficiency may result from a wide variety of congenital or acquired disorders of hypothalamus, pituitary, or adrenal cortex. Destruction or dysfunction of the adrenal cortex is the cause of primary adrenal insufficiency, while secondary adrenal insufficiency is a result of pituitary or hypothalamic disease. Timely diagnosis and clinical management of adrenal insufficiency are critical to prevent morbidity and mortality. This review summarizes the etiologies, presentation, and diagnosis of adrenal insufficiency utilizing different dynamic hormone testing and describes current treatment recommendations and new therapies.

The ICET-A Survey on Current Criteria Used by Clinicians for the Assessment of Central Adrenal Insufficiency in Thalassemia: Analysis of Results and Recommendations

BACKGROUND

In March 2015, the International Network of Clinicians for Endocrinopathies in Thalassemia and Adolescent Medicine (ICET-A) implemented a two-step survey on central adrenal insufficiency (CAI) assessment in TM patients and after analysis of the collected data, recommendations for the assessment of hypothalamic-pituitary- adrenal (HPA) axis in clinical practice were defined.

METHODS

To ascertain the current practice for assessment of CAI in thalassemia, the Coordinator of ICET-A sent two questionnaires by email: i) The first to evaluate the current interpretation of basal serum cortisol level (first step) and ii) The second to assess the current usage of ACTH test and the variability in practice" (second step). Based on the surveys the core ICET-A group prepared the recommendations for the assessment of suspected CAI in thalassemia (third step).

RESULTS

A total of 19 thalassemologists/endocrinologists have participated in the first survey and 35 specialists participated in the second step questionnaire. The study demonstrated a considerable variability in almost all aspects of relevant current criteria used for the diagnosis of CAI. An ROC analysis using peak value > 20 μg/dl (> 550 nmol/L), after ACTH stimulation test, was performed with the aim of identifying the optimal basal serum cortisol cut-off. The optimal threshold that maximizes sensitivity plus specificity for morning basal cortisol against peak post-ACTH value >20 μg/dl (>550 nmol/L) was 10 μg/dl (275 nmol/L). Furthermore, the values associated with the highest negative predictive value (NPV) and highest, positive predictive value (PPV) were 4.20 (115 nmol/L) and 18.45 μg/dl (510 nmol/L), respectively. Surprisingly, 20 specialists in thalassemia working in blood bank, thalassemia centres (day hospital), internal medicine, hematology and onco-hematology had poor knowledge and experience in testing for CAI and stopped filling the questionnaire after the second question. In contrast, 9 endocrinologists (8 pediatricians) and 6 hematologists working in collaboration with endocrinologists completed the questionnaire.

CONCLUSIONS

While waiting for more extensive adequately powered and targeted studies, physicians should adopt an acceptable policy for accurate assessment of HPA in TM patients. Regular surveillance, early diagnosis, treatment and follow-up in a multi-disciplinary specialized setting are also recommended. The ICET-A recommendations are reported in order to facilitate for interested physicians the approach to a successful assessment of adrenal function in thalassemia.

Suppression and recovery of adrenal response after short-term, high-dose glucocorticoid treatment

BACKGROUND

Suppression of the adrenal response is an unpredictable consequence of glucocorticoid treatment. To investigate the kinetics of the adrenal response after short-term, high-dose glucocorticoid treatment, we measured the adrenal response to the low-dose (1 microg) corticotropin stimulation test.

METHODS

We studied 75 patients who received the equivalent of at least 25 mg prednisone daily for between 5 days and 30 days. After discontinuation of glucocorticoid treatment, 1 microg corticotropin was administered intravenously, and stimulated plasma cortisol concentrations were measured 30 min later. In patients with a suppressed response to 1 microg corticotropin, the test was repeated until stimulated plasma cortisol concentrations reached the normal range.

FINDINGS

The adrenal response to 1 microg corticotropin was suppressed in 34 patients and normal in 41. Subsequent low-dose corticotropin tests showed a steady recovery of the adrenal response within 14 days. In two patients, the adrenal response remained suppressed for several months. There was no correlation between plasma cortisol concentrations and the duration or dose of glucocorticoid treatment.

INTERPRETATION

Suppression of the adrenal response is common after short-term, high-dose glucocorticoid treatment. The low-dose corticotropin test is a sensitive and simple test to assess the adrenal response after such treatment.