A critical evaluation of signs and symptoms in the diagnosis of Addison's diseases

OBJECTIVES

To determine the usefulness of clinical symptoms and signs in the diagnosis of Addison's disease.

METHODOLOGY

A retrospective, hospital based study from analysis of case records of over 12 years period (1988-1999). Individual or groups of signs and symptoms in 66 patients of confirmed Addison's diseases were compared with 76 subjects with normal ACTH stimulation test, when clinical presentations were similar.

RESULTS

Age spectrum of the two groups was similar. Signs and symptoms like weakness, weight loss, gastro-intestinal disturbances, skin/mucosal pigmentation and blood pressure were not statistically different between the two groups. Similarly blood glucose, sodium and potassium were not different between the two groups. Combination of three or more symptoms/signs had a high predictive value of diagnosing the disease than any individual or a combination of < 3 signs/symptoms (P=0.033).

CONCLUSIONS

Combination of skin and mucosal pigmentation with gut disturbances and weight loss carried high predictive value in diagnosis of Addison's disease, while individual sign and symptom has poor differentiating value.

Liver involvement and abnormal iron variables in undiagnosed Addison's disease

OBJECTIVE

To describe a case of untreated Addison's disease manifesting as severe gastrointestinal symptoms, persistently increased liver enzymes, substantially increased ferritin, and hepatic iron deposition and to document changes in these variables after corticosteroid replacement.

METHODS

We thoroughly reviewed the clinical history and results of laboratory tests before and after treatment in a 23-year-old man during a period of 18 months. The relevant medical literature was also reviewed.

RESULTS

The study patient had frequent episodes of severe abdominal symptoms, hemodynamic instability, and electrolyte imbalance. He underwent extensive laboratory investigations and was prescribed various treatment regimens. Increased levels of serum transaminases, ferritin, and transferrin saturation led to a liver biopsy, which showed lymphocytic infiltration and increased iron deposition. Eventually, cosyntropin stimulation (250 microg) confirmed the presence of adrenal insufficiency, and these abnormalities resolved after institution of daily administration of glucocorticoids and mineralocorticoids.

CONCLUSION

Addison's disease can be a cause of unexplained hypertransaminasemia and profoundly increased ferritin levels. These changes are reversible but may lead to diagnostic confusion and delay in commencement of lifesaving corticosteroid therapy.

The diurnal rhythm of adrenocorticotropic hormone secretion in the assessment of the adequacy of replacement therapy in primary chronic adrenal failure

Utilization of the daily rhythm of ACTH secretion was assessed as a measure of the adequacy of replacement therapy in primary chronic adrenal failure (PCAF: Addison's disease) with glucocorticoids (GC) by assaying plasma ACTH by radioimmunoassay every 4 h for one day in three groups of patients. Patients of group 1 had PCAF (n = 14) and received replacement therapy consisting of prednisolone (5 mg at 09:00 and 2.5 mg at 14:00) and group 2 patients received dexamethasone (0.5 mg at 23:00) in combination with prednisolone (2.5 mg at 14:00). All patients with PCAF also received 0.005-0.01 mg/day of 9alpha-fluorocortisol. The control group consisted of 14 healthy volunteers. Both types of replacement therapy resulted in high levels of variability in ACTH levels as compared with that in normal subjects. The areas under the curve (AUC) of the ACTH concentration over one day were not significantly different between groups 1 and 2 or between group 2 and controls. The AUC of ACTH in group 1 was significantly larger than that in controls. The mean ACTH concentration in group 1 at 07:00 and 11:00 was significantly greater than those in the other two groups. The daily rhythm of ACTH was generally closer to normal in patients given dexamethasone. Since our own clinical experience shows that at least two thirds of patients are initially given dexamethasone and that this had to be withdrawn because of the development of overdosage syndrome (weight gain, increased appetite, insomnia), it appears that there is a lack of concordance between the clinical data and the daily rhythm of ACTH secretion. When assessing the adequacy of replacement therapy in PCAF, it is important to note that the appearance of a normal rhythm of ACTH secretion over one day does not exclude the possibility of GC overdosage, with the effect that interpretation of the results of this type of measurement must take the clinical picture into account.

Hypoadrenocorticism in a cat

Primary hypoadrenocorticism was diagnosed in an eight-year-old neutered male cat. The predominant presenting complaint was dysphagia. Other historical signs included lethargy, weight loss, polydipsia, polyuria, muscle weakness and occasional vomiting. The signs had waxed and waned over the two months before presentation and had improved when the cat was treated with enrofloxacin and prednisolone by the referring veterinarian. On referral, dehydration, depression and poor bodily condition were found on physical examination. Results of initial laboratory tests revealed mild anaemia, hyperkalaemia, hyponatraemia, hypochloraemia and elevations in serum creatinine and creatine kinase. The diagnosis of primary adrenocortical insufficiency was established on the basis of results of an adrenocorticotropic hormone (ACTH) stimulation test and endogenous plasma ACTH determination. Initial therapy for hypoadrenocorticism included intravenous administration of 0.9 per cent saline and dexamethasone, and oral fludrocortisone acetate. Within one week the cat was clinically normal and two years later was still alive and well on fludrocortisone acetate treatment only.

Diagnosis of adrenal cortical dysfunction by liquid chromatography-tandem mass spectrometry

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to measure 6 metabolic compounds of the adrenocorticosteroid pathway simultaneously on residual specimens from patients who had previously been previously diagnosed, on the basis of immunoassays, as having congenital adrenal hyperplasia (CAH), 11 beta-hydroxylase deficiency, 21-hydroxylase deficiency, or Addison disease (adrenal insufficiency). Two subjects with normal adrenal function had serum cortisol values of 13.6 and 8.9 micrograms/dL and serum cortisone values of 2.1 and 0.6 microgram/dL, but the rest of the compounds were undetectable. Two patients with 11 beta-hydroxylase deficiency had serum 11 beta-deoxycortisol values of 14.9 and 10.0 micrograms/dL and serum 11-deoxycorticosterone values of 3.9 and 1.0 microgram/dL, but their serum levels of cortisol and cortisone were diminished. A patient with 21-hydroxylase deficiency had a highly increased serum 17-hydroxyprogesterone concentration of 28.5 micrograms/dL (or 28,500 ng/dL, the traditional unit to report this assay) and a serum 21-deoxycortisol concentration of 6.9 ug/dL (this is a pathologic marker of 21-hydroxylase deficiency that is nondetectable in sera of healthy subjects). This patient also had diminished concentrations of serum cortisol and cortisone (0.9 and 0.3 microgram/dL, respectively). At 30 and 60 min after corticotropin (ACTH) stimulation, serum cortisol was the only compound that showed a dramatic increase in the normal subjects; the patient with 21-hydroxylase deficiency showed an increase of serum 17-hydroxyprogesterone level, but no increase of serum cortisol level; the patient with Addison disease showed no increase in the levels of serum cortisol or other compounds. Metyprapone, which blocks 11 beta-hydroxylase activity, increased the serum 11-deoxycorticosteroid levels and decreased the serum cortisol level. This pilot study demonstrates that it is feasible to use LC-MS/MS for the laboratory diagnosis of adrenal cortical dysfunction. The authors envision that LC-MS/MS may soon become an ideal analytical technique for the diagnosis of such endocrine diseases.

Hydrocortisone replacement dosage influences intraocular pressure in patients with primary and secondary hypocortisolism

BACKGROUND

It has been suggested that the variation of intraocular pressure (IOP) during the day follows the diurnal variation of serum cortisol. There is also a higher risk of ocular hypertension and glaucoma in patients taking excessive oral steroid treatment. We assessed whether different replacement doses of hydrocortisone (HC) influenced IOP.

METHODS

Seventeen patients (six Addison's disease, 11 hypopituitarism; seven males) aged 24-58 years mean 42.7 years and 20 control subjects (nine males) aged 20--59 years mean 38.7 years were studied. On the first visit, the 17 patients had been taking HC replacement doses, 20 mg morning and 10 mg afternoon. Serum cortisol and IOP in both eyes (Goldmann applanation tonometer) were measured at 0900, 1100, 1300, 1500, 1700 hours with HC 20 mg taken after the 0900 h assessment. The dose of HC was then reduced to 10 mg morning and 10 mg afternoon for 1 week and the measurements were repeated in 16 patients, with HC 10 mg taken at 0900 h.

RESULTS

In the patients the peak serum cortisol occurred at 1100 h after the 0900 h HC dose. Cortisol levels were significantly higher at 1100, 1300, 1500 and 1700 h after taking 20 mg compared to 10 mg HC. The mean (SEM) IOP (mmHg) was significantly higher after 20 mg HC compared with 10 mg HC at 1300 h: 14.7(0.6) v 13.1(0.6) (P = 0.004) and at 1500 h: 14.4(0.6) v 13.1(0.5) (P = 0.04). The total mean (SEM) daily IOP score was significantly higher after 20 mg HC compared with 10 mg HC: 14.5(0.3) v 13.5(0.3) (P = 0.0002). The total mean (SEM) daily IOP score after the 20 mg HC dose compared with the control subjects was: 14.5(0.3) v 13.7(0.3) (P = 0.08).

CONCLUSION

Intraocular pressures during the day are influenced by the morning hydrocortisone replacement dosage with significantly higher intraocular pressure levels in the early afternoon following 20 mg compared with 10 mg. A morning hydrocortisone dose of 10 mg leads to a more physiological intraocular pressure profile during the day. These data support the view that a daily replacement dose of 30 mg hydrocortisone may be excessive.

High-throughput radioassays for autoantibodies to recombinant autoantigens

Advances in immunology, biochemistry, and molecular biology have combined to allow the development of a large series of autoantibody assays utilizing recombinantly produced autoantigens. Labeled target proteins can be readily produced by in vitro transcription and translation of relevant cloned cDNA. The assays are carried out in the fluid phase and for most assays are more specific and sensitive than ELISA based assays. For some antigens (e.g. insulin) though ELISA assays detect antibodies following immunization, workshops indicate they are almost worthless for the diagnosis and prediction of type 1A diabetes. This new generation of radioassays is usually carried out in 96-well microtiter filtration plates that allow high throughput. Given such assays, individuals at high risk for type 1A diabetes, celiac disease, and Addison's disease can now be readily identified.

Oral dehydroepiandrosterone (DHEA) replacement therapy in women with Addison's disease

OBJECTIVE

Patients with primary adrenocortical failure (Addison's disease) have abnormally low levels of DHEA and androgens relative to age. To define a suitable dose, the effect of oral dehydroepiandrosterone (DHEA) replacement therapy in women with Addison's disease (n = 9) was evaluated.

DESIGN AND MEASUREMENTS

DHEA was administered as a daily oral dose of either 50 mg (n = 5) or 200 mg (n = 4). Blood sampling and measurements of insulin sensitivity (as measured with euglycemic insulin clamp technique) and body composition (as measured by dual energy X-ray absorptiometry) were performed before and during DHEA treatment and at a 3-month follow up.

RESULTS

DHEA and DHEA(S) levels were restored to normal in those patients receiving 50 mg whereas DHEA(S) level was slightly above the normal reference value in those receiving 200 mg. Circulating levels of androgens (androstenedione, testosterone and testosterone/SHBG ratio) were normalized in all patients. A slight rise in IGF-1 levels was seen in both groups as was a decrease in the levels of low and high density lipoproteins. No effect on blood glucose levels or insulin sensitivity was seen and no change of body composition was observed. No serious side-effects were seen, but some of the patients experienced increased apocrine sweat secretion (n = 7), itchy scalp (n = 2) and acne (n = 7), all of which were reversed when DHEA was discontinued.

CONCLUSION

A daily replacement dose of 50 mg of DHEA results in near physiological levels of DHEA, DHEA(S) androstenedione and testosterone in women with Addison's disease, without severe side-effects.

Detection of binding and blocking autoantibodies to the human sodium-iodide symporter in patients with autoimmune thyroid disease

The sodium iodide symporter (NIS) is a novel autoantigen in autoimmune thyroid disease (ATD). A recent study has described the development of a bioassay for human (h) NIS antibody detection, but this will not detect antibodies that bind the symporter without modulating its activity. Therefore, the establishment of a binding assay is of importance to determine the overall prevalence of hNIS antibodies in ATD patients. An in vitro transcription and translation system was used to produce [35S]-labeled hNIS. The radiolabeled ligand reacted specifically in immunoprecipitation experiments with rabbit antiserum raised against a peptide fragment of hNIS. Subsequently, the reactivity of control and ATD sera to translated [35S]hNIS was determined using RIAs. A significant difference in the frequency of hNIS antibody-positive sera was found when patients with either Graves' disease (GD) or autoimmune hypothyroidism (AH) were compared with normal controls (P = 0.01 and P = 0.03, respectively). Of 49 GD and 29 AH sera tested, 11 (22%) and 7 (24%), respectively, were found to contain hNIS antibodies. Differences were also significant when the antibody-binding indices of the control group of sera were compared with those of both the GD and the AH patient sera (P < 0.0001 and P = 0.001, respectively). In contrast, sera from 10 patients with Addison's disease and 10 patients with vitiligo (without associated ATD) were all negative for antibody reactivity to the symporter. No differences were detected when the antibody binding indices of either the Addison's disease or the vitiligo sera were compared with those of the normal sera group (P = 0.9 and P = 0.6, respectively). Eight of the 11 (73%) GD and 3 of the 7 (43%) AH sera, which were positive for hNIS antibodies in the immunoprecipitation assay, were also found to inhibit iodide uptake in hNIS-transfected CHO-K1 cells, suggesting the existence of antibodies in some serum samples that bind to the symporter without modulating its function. Overall, a significant correlation was found between the iodide uptake inhibition and the binding assays for hNIS antibody detection (r = 0.49, P < 0.0001). In summary, we have developed a specific and quantitative assay for the detection of hNIS binding antibodies in sera of patients with ATD. This system offers the advantage of studying antibody reactivity against conformational epitopes and will be useful in understanding the role of NIS autoreactivity in the pathogenesis of ATD.

An unusual cause of postpartum vomiting

We are presenting this case to emphasize that the symptoms of Addison disease are very similar to those of pregnancy and, although this disease is rare, the consequences can be catastrophic if it is overlooked, particularly in pregnancy.

Autoantibodies to adrenal cytochrome P450 antigens in isolated Addison's disease and autoimmune polyendocrine syndrome type II

Adrenal P450 enzymes 21-hydroxylase (21OH), 17alpha-hydroxylase (17OH) and side chain cleavage enzyme (SCC) represent major target antigens in adrenal autoimmunity. To evaluate the diagnostic sensitivity of autoantibodies to recombinant adrenal antigens we established rapid and sensitive radioligand assays and compared the results with adrenocortical autoantibodies (ACA) as detected by the standard immunofluorescence test. A high prevalence of antibodies to 21OH (21OH-A) was observed in patients with isolated Addison's disease (IAD) and patients suffering from autoimmune polyendocrine syndrome type II (APS II). 21OH-A were found in 19 of 25 (76%) patients with IAD and in 34 of 40 (85%) patients with APS II. In contrast, antibodies to 17OH (17OH-A) as well as antibodies to SCC (SCC-A) were detected in 12 (30%) and 13 (33%) patients with APS II whereas only a few sera from patients with IAD had 17OH antibodies (n = 3) and SCC-A (n = 1), respectively (p < 0.0001). The majority of patients with 17OH-A (83.3%) or SCC-A (76.9%) were also found positive for 21OH-A and all three antibody specificities were positively correlated with the presence of ACA. Among 52 sera with ACA 49 (94.2%), 11 (21.2%), and 9 (17.3%) were positive for 21OH-A, 17OH-A and SCC-A, respectively. By combination of 21OH-A with 17OH-A all ACA positive individuals were identified. The availability of recombinant steroid P450 enzymes made it possible to develop radiobinding assays which allow simple, sensitive and quantitative detection of autoantibodies to defined adrenal autoantigens. We here demonstrate that autoantibodies to 21-hydroxylase are sensitive markers for autoimmune Addison's disease with and without polyglandular failure. The presence of 17OH-A or SCC-A may suggest the coexistence of or progression towards polyglandular autoimmunity.

The effects of endogenous opioids and cortisol on thyrotropin and prolactin secretion in patients with Addison's disease

This study assessed the controversial role of endogenous opioids and cortisol in the regulation of TSH and PRL secretion in humans. Seven euthyroid male patients with Addison's disease were studied four times, with an interval of 1-3 months, as follows: 1) during normocortisolism [graduated infusion of hydrocortisone, 0.4 mg/kg, over 19.5 h]; 2) normocortisolism and coadministration of naloxone, at 25 microg/kg x h during the last 6.5 h; 3) hypocortisolism (24 h withdrawal of hydrocortisone, followed by 19.5 h saline infusion); and 4) hypocortisolism plus naloxone administration. The TSH and PRL levels were measured every 15 min, from 0800-1530 h. A TRH test was performed at 1300 h and 1400 h (10 microg and 200 microg of TRH, respectively). The mean TSH level increased significantly during hypocortisolism, compared with normocortisolism (1.78 +/- 0.04 vs. 0.84 +/- 0.02 mU/L; P < 0.001). The administration of naloxone suppressed the TSH levels during hypo- and normocortisolism (1.78 +/- 0.04 vs. 1.50 +/- 0.03 and 0.84 +/- 0.02 vs. 0.61 +/- 0.02 mU/L, respectively; P < 0.001). During hypocortisolism, the TSH responses to small and high doses of TRH were significantly higher than during normocortisolism (P < 0.02). Naloxone had no effect on the TSH responses to TRH, neither during hypo- nor during normocortisolism. The mean PRL level increased significantly during hypocortisolism, compared with normocortisolism (5.8 +/- 0.4 vs. 3.6 +/- 0.2 microg/L; P < 0.001), and naloxone induced an increase in PRL levels both during hypo- and normocortisolism (7.1 +/- 0.7 vs. 4.7 +/- 0.5 microg/L, respectively; P < 0.01). The PRL responses to TRH were similar during hypo- and normocortisolism and without any change during opioid receptor blockade. In conclusion, cortisol suppressed basal TSH and PRL secretion and reduced the sensitivity of the thyrotrophs to TRH, without affecting the PRL response to TRH. Our results suggest that endogenous opioids act at the hypothalamic level to stimulate TSH secretion and to suppress the PRL secretion, but these results argue against an essential role of endogenous opioids in the physiological regulation of TSH and PRL secretion in humans.

A high-sensitivity test in the assessment of adrenocortical insufficiency: 10 microg vs 250 microg cosyntropin dose assessment of adrenocortical insufficiency

The short cosyntropin (synthetic ACTH) test is recognized as the best screening manoeuvre in the assessment of adrenocortical insufficiency. Recent data, however, suggest that i.v. administration of 250 microg cosyntropin could be a pharmacological rather than a physiological stimulus, losing sensitivity for detecting adrenocortical failure. Our objective was to compare 10 vs 250 microg cosyntropin in order to find differences in serum cortisol peaks in healthy individuals, the adrenocortical response in a variety of hypothalamic-pituitary-adrenal axis disorders and the highest sensitivity and specificity serum cortisol cut-off point values. The subjects were 83 healthy people and 37 patients, the latter having Addison's disease (11), pituitary adenomas (7), Sheehan's syndrome (9) and recent use of glucocorticoid therapy (10). Forty-six healthy subjects and all patients underwent low- and standard-dose cosyntropin testing. In addition, 37 controls underwent the low-dose test. On comparing low- and standard-dose cosyntropin testing in healthy subjects there were no statistical differences in baseline and peaks of serum cortisol. In the group of patients, 2 out of 11 cases of Addison's disease showed normal cortisol criterion values during the standard test but abnormal during the low-dose test. In our group of patients and controls, the statistical analysis displayed a better sensitivity of the low-dose vs standard-dose ACTH test at 30 and 60 min. In conclusion, these results suggest that the use of 10 microg rather than 250 microg cosyntropin i.v. in the assessment of suspicious adrenocortical dysfunction gives better results.

Hypertransaminasaemia and Addison's disease

A 37-year-old man with hypertransaminasaemia, astenia, anorexia and weight loss is presented. After a search for the usual causes of hypertransaminasaemia, without a positive result, finally Addison's disease was diagnosed. This is an association that is very rarely published.

A novel presentation of Addison disease: hypoglycemia unawareness in an adolescent with insulin-dependent diabetes mellitus

A 16-year-old boy with insulin-dependent diabetes mellitus (IDDM) and a history of marginal glycemic control had severe hypoglycemia unawareness and a marked decrease in insulin requirement. His counterregulatory hormone response at the time of hypoglycemia suggested adrenocortical and adrenomedullary dysfunction. Further testing confirmed Addison disease. The patient's hypoglycemia unawareness was reversed by glucocorticoid replacement, although the plasma epinephrine response to hypoglycemia remained undetectable.

Biochemical testing of adrenocortical function

Disturbed adrenal function may present in various ways. Here are outlined some of the functions of the adrenals and the clinical effects of adrenal disorder, followed by a more detailed consideration of the application of laboratory tests to the identification of adrenocortical hypo- and hyperfunction.

Tuberculous Addison's disease: lack of normalization of adrenocortical function after anti-tuberculous chemotherapy

OBJECTIVE

Tuberculosis of the adrenal glands is a common cause of Addison's disease in developing countries. We conducted a study to determine if treatment of such patients with modern anti-tuberculous chemotherapy would lead to an improvement in plasma cortisol and aldosterone levels.

DESIGN

Prospective study.

PATIENTS

5 patients with Addison's disease secondary to tuberculosis.

MEASUREMENTS

Basal and ACTH stimulated plasma cortisol and aldosterone levels were measured prior to instituting anti-tuberculous chemotherapy, as well as one month after its conclusion. Four patients were again studied over the next 2-5 years.

RESULTS

Peak plasma cortisol levels prior to treatment were markedly reduced (range, < 14-110 mumol/l). There was no improvement one month (< 14-143 mumol/l) or 2-5 years (< 14-69 mumol/l) after completing anti-tuberculous chemotherapy. Peak plasma aldosterone at diagnosis was < 56-210 pmol/l; it was undetectable in 4 patients. No improvement was observed one month (< 56-210 pmol/l), or 2-5 years (< 56-389 pmol/l) after stopping anti-tuberculous chemotherapy. Plasma aldosterone levels at both these time points were far lower than those in control subjects (median 736 pmol/l, 560-1512 pmol/l; p < 0.01). One patient had an increase in peak aldosterone from < 56 pmol/l to 389 pmol/l, though peak cortisol actually declined in this subject (from 110 mumol/l to 69 mumol/l).

CONCLUSIONS

Treatment of tuberculous Addison's disease with anti-tuberculous chemotherapy does not lead to normalization of ACTH stimulated plasma cortisol or aldosterone levels during the 2-5 year period of study. However, prolonged follow up with regular adrenal function tests is warranted in all such patients.

Circulating levels of adrenomedullin in patients with Addison's disease before and after corticosteroid treatment

BACKGROUND AND OBJECTIVE

A novel hypotensive peptide, adrenomedullin (AM), had recently been isolated, purifed and its encoding gene sequenced from a human phaeochromocytoma. In humans AM circulates in physiological levels and possesses a distinct vasodilatatory activity. The purpose of this study was to examine the behaviour of AM levels in primary adrenal failure.

DESIGN

Plasma AM levels were measured in patients with proven Addison's disease using a specific radioimmunoassay and compared to those in healthy normotensive subjects.

PATIENTS

Eighteen patients with Addison's disease (10 men and eight women; ages 21 to 72 years) and 21 healthy control subjects (13 men and eight women; ages 20 to 71 years) were enrolled in the study. All patients were studied under basal conditions and 10 were reassessed following corticosteroid treatment.

RESULTS

All patients with Addison's disease showed increased levels of AM compared to the control group. Mean plasma AM levels were correspondingly higher in patients with Addison's disease than in normal subjects (102.1 +/- 33.4 (SD) ng/l versus 13.7 +/- 6.1 ng/l; P < 0.0001). In 10 patients studied after corticosteroid treatment, plasma AM levels were significantly reduced (P < 0.0001: 110.3 +/- 35.8 ng/l versus 32.4 +/- 10.3 ng/l) after 2 weeks of treatment. A weak correlation (r = 0.458; P = 0.048) was observed between systolic blood pressure and plasma AM concentrations in all patients with Addison's disease.

CONCLUSIONS

These results indicate a consistent but reversible increase of adrenomedullin in patients with Addison's disease.

A study of the epitopes on steroid 21-hydroxylase recognized by autoantibodies in patients with or without Addison's disease

Steroid 21-hydroxylase (21-OH) autoantibodies are found in patients with autoimmune Addison's disease (AAD), either isolated or associated with autoimmune polyglandular syndrome (APS) type I and II and in adrenal-cortex autoantibody (ACA)-positive patients without AAD. In order to assess any differences in the 21-OH autoantibodies in these different patient groups, we have studied their reactivity with different epitopes on 21-OH using full length and modified 35S-labelled 21-OH proteins produced in an in vitro transcription/translation system. There were no major differences in the pattern of autoantibody reactivity with the different modified 21-OH proteins in patients with isolated AAD or with APS types I and II, and in 21-OH autoantibody-positive patients with clinical AAD, subclinical AAD and those maintaining a normal adrenal function. Our studies also indicate that the main epitopes for 21-OH autoantibodies in patients with different forms of autoimmune adrenal disease are located in the C-terminal end and in a central region of 21-OH.

Sudden death due to auto-immune Addison's disease in a 12-year-old girl

A 12-year-old female suffering from adrenocortical insufficiency showed symptoms similar to a gastro-enteritis, and severe electrolytic and acid/base disturbances which progressed into cerebral oedema and death. Autopsy findings included depletion of the adrenal cortex, with enlargement and eosinophilia of surviving cells. In ante-mortem blood, anti-adrenal auto-antibodies were found and elevated levels of ACTH and cortisol with a low level of aldosterone.

Effect of desmopressin on ACTH and cortisol secretion in states of ACTH excess

OBJECTIVE

To assess the ability of desmopressin administration to stimulate ACTH/cortisol secretion in patients with Cushing's disease, either before or after surgery, and in patients with other states characterized by ACTH hypersecretion, and to compare the results with those obtained after CRH testing.

DESIGN AND SUBJECTS

Plasma ACTH and serum cortisol levels were evaluated after the administration of desmopressin (10 micrograms i.v.), CRH (1 microgram/kg i.v.) and saline on different days in 17 patients with Cushing's disease, 1 with occult ectopic ACTH syndrome, 5 with Addison's disease, 3 who had been bilaterally adrenalectomized for Cushing's syndrome and 4 normal subjects. After pituitary adenomectomy desmopressin and CRH were administered again to 13 of the patients who had undergone pituitary surgery for their Cushing's disease.

RESULTS

In 16 patients with Cushing's disease with microadenoma a positive ACTH/cortisol rise occurred in 11 patients after both desmopressin and CRH, 2 other patients were responsive only to desmopressin and 2 only to CRH, while in 1 patient equivocal responses to both tests were found. The persistence of a hormonal response to desmopressin after pituitary adenomectomy for Cushing's disease correlated with unsuccessful surgery, while, contrary to CRH, absent ACTH/cortisol rises were found in cured patients 1 and 12 months after operation. In 1 patient suspected for ectopic ACTH hypersecretion, desmopressin and CRH administration did not cause any ACTH/cortisol rise. Significant ACTH rises occurred after both desmopressin and CRH testing in patients with Addison's disease. All the 3 patients adrenalectomized for Cushing's syndrome showed a rise of ACTH levels after CRH, while a similar response after desmopressin occurred in only one of them.

CONCLUSIONS

Desmopressin is able to stimulate ACTH and hence cortisol release in Cushing's disease. It may be a useful test in patients with doubtful responses to CRH test, in those exhibiting responses to CRH indistinguishable from those of normal subjects and in the postoperative follow-up of Cushing's disease. In some patients with abolished or reduced cortisol feed-back at hypothalamic-pituitary level the sensitivity of normal corticotrophs to desmopressin is enhanced.

Glucocorticoid replacement therapy: are patients over treated and does it matter?

BACKGROUND AND OBJECTIVES

Adequate assessment of patients on glucocorticoid replacement therapy is of great importance to avoid the consequences of under or over treatment, but no simple test is available for this. The aims of this study were (1) to assess adequacy of glucocorticoid replacement in hypoadrenal patients, (2) to correlate serum cortisol levels (cortisol day curve) with 24-hour urine free cortisol excretion and (3) to assess the impact of glucocorticoid dose optimization on markers of bone formation and bone resorption.

DESIGN

Cross-sectional study of current replacement therapy and a prospective study of the effect of dose alteration on bone turnover markers.

PATIENTS

Thirty-two consecutive patients on replacement glucocorticoid therapy (12 Addison's disease, 20 hypopituitarism) from a University teaching hospital out-patient department.

MEASUREMENTS

Serum and urinary cortisol, osteocalcin, N-telopeptide of type I collagen (NTX) and bone mineral density.

RESULTS

28/32 (88%) patients required a change of therapy; 24/32 (75%) a total reduction in dose, 18/32 (56%) a change in replacement therapy regimen or drug and 14/32 (44%) both changes. The mean daily dose of hydrocortisone was reduced from 29.5 +/- 1.2 to 20.8 +/- 1.0 mg. A significant correlation was found between peak cortisol and 24-hour urine free cortisol/ creatinine (Spearman correlation r = 0.60, P < 0.0001; n = 51). Following hydrocortisone dose reduction, median osteocalcin increased from 16.7 micrograms/l (range 8.2-65.7) to 19.9 micrograms/l (8.2-56.3); P < 0.01, with no change in the NTX/creatinine ratio.

CONCLUSIONS

A high proportion of patients on conventional corticosteroid replacement therapy are over treated or on inappropriate replacement regimens. To reduce the long term risk of osteoporosis, corticosteroid replacement therapy should be individually assessed and over replacement avoided.

Primary adrenal lymphoma associated with adrenal insufficiency: a distinct clinical entity

We describe a case of a 42 year old male who presented with Addison's disease resulting from primary lymphoma of the adrenals. Our case and a review of the literature indicates that this distinct entity has some unique clinical and radiologic features. In this entity, the lymphoma tends to be extranodal and have a poor prognosis. In addition, the computed tomography (CT) images have the unique appearance of enlargement of the adrenal gland with maintenance of the adreniform shape. We suggest that primary adrenal lymphoma is a distinct clinical entity and should be considered in patients with an elevated serum lactate dehydrogenase, characteristic CT findings and Addison's disease.

Steroid 21-hydroxylase autoantibodies in insulin-dependent diabetes mellitus. Childhood Diabetes in Finland (DiMe) Study Group

We have studied the sera from 304 patients with insulin-dependent diabetes mellitus (IDDM) for steroid 21-hydroxylase (P450c21) autoantibodies by an in vitro translation and immunoprecipitation assay. Autoantibodies to P450c21 were found in 7 patients with IDDM (2.3%). When the IDDM patients with P450c21 antibodies were analyzed for their HLA, 6 of them (86%) belonged to the HLA DQB1*0201-positive group. A strong correlation (r = 0.91, P < 0.001) of immunoprecipitation results was observed with adrenocortical autoantibodies detected by indirect immunofluorescence, indicating that the adrenal autoantibodies in patients with IDDM were anti-P450c21 autoantibodies. The levels of P450c21 autoantibodies were significantly higher (P < 0.05) in patients with IDDM than in 13 (9 P450c21 autoantibody positive) patients with Addison's disease. Although the occurrence of P450c21 antibodies in IDDM was relatively low, antibody-positive patients had high antibody levels and may have an ongoing subclinical process of adrenal autoimmunity.

High plasma levels of endothelin-1 in untreated Addison's disease

The aim of this study has been to investigate the plasma endothelin-1 (ET-1) levels in adult patients with proven Addison's disease (AD). Plasma ET-1 levels were measured in 29 subjects (17 males and 12 females, aged between 20 and 54 years): 15 of them were patients with AD and 14 were sex- and age-matched normal subjects, used as a control group. All patients with AD have been studied under basal conditions and nine of them also after 2 weeks on oral corticosteroid therapy (individual cortisol dosage ranging from 25 to 37.5 mg/day and 0.1 mg/day 9 alpha-fluorohydrocortisone). Extracted plasma ET-1 was determined by a specific radioimmunoassay using rabbit endothelin antisera. Mean ET-1 values in the patients with AD were three times higher than in normal subjects (21.09 +/- 4.38 pg/ml vs 6.72 +/- 1.74 pg/ml; p < 0.0001). Plasma ET-1 levels assayed in the patients with AD after 2 weeks of corticosteroid therapy were significantly decreased (14.47 +/- 3.7 pg/ml vs 22.8 +/- 5.2 pg/ml; -37%; p < 0.001) compared to values in untreated patients. However, the plasma ET-1 values obtained following corticosteroid therapy were still significantly higher (p < 0.001) than those detected in the control subjects. These results clearly indicate that patients with untreated AD have increased circulating ET-1 levels that may be reduced by short-term corticosteroid therapy.

Mineralocorticoid insufficiency due to suramin therapy

BACKGROUND

During a Phase I trial of suramin, a novel antineoplastic agent with activity against hormone-refractory prostate carcinoma, the authors observed two patients with clinical mineralocorticoid insufficiency in spite of hydrocortisone replacement therapy.

METHODS

The authors retrospectively assessed adrenal cortical function in 20 such patients via adrenocorticotropic stimulation testing, measuring both cortisol and aldosterone responses, either at the time or treatment of immediately after discontinuation of treatment.

RESULTS

Two of 9 patients (22%) treated at relatively low dose levels (< or = 1200 mg/m2 on Day 1) demonstrated adrenal cortical insufficiency, as compared with 9 of 11 patients (32%) treated with relatively high doses (> 1200 mg/m2 on Day 1) (P = 0.03 by 1-tailed Fisher's exact test). There appeared to be a cumulative dose-response relationship to the development of glucocorticoid insufficiency, with no instances being observed at doses < 4.8 g/m2 and uniform toxicity occurring at doses > 7.6 g/m2. Long term glucocorticoid insufficiency was present in 1 of 5 patients (20%) tested at an interval of > 90 days after discontinuation of suramin treatment. All instances of glucocorticoid insufficiency were associated with mineralocorticoid insufficiency. Suramin did not affect the absorption or excretion of exogenously administered glucocorticoid in one patient.

CONCLUSIONS

Suramin causes both primary mineralocorticoid and primary glucocorticoid insufficiency. This may occur in a dose-dependent manner. Long term glucocorticoid insufficiency appears to occur in a minority of patients treated with low doses of suramin. Patients receiving high doses of suramin for treatment of advanced carcinoma should receive at least physiologic replacement doses of both mineralocorticoid and glucocorticoid. Higher doses of glucocorticoid may be required in selected patients.

High plasma proopiomelanocortin in aggressive adrenocorticotropin-secreting tumors

A specific propiomelanocortin (POMC) immunoradiometric assay was developed using antibodies directed against ACTH and beta-endorphin (beta end). Partially purified standard POMC was prepared from the human small cell lung carcinoma cell line DMS-79 culture medium. Ten units (U) POMC had the same displacement ability as one pg beta end in a C-terminal beta end radioimmunoassay and thus were close if not equal to 10 pg POMC. This POMC assay was used to investigate patients with ACTH-dependent Cushing's syndrome. Plasma POMC was undetectable (< 60 U/mL) in 17 normal controls and in 4 patients with Addison's disease (concomitant ACTH plasma levels between 362 and 1058 pg/mL). Forty-two patients with Cushing's disease were studied, either before (n = 25) or after (n = 17) bilateral adrenalectomy: 7 patients with highly invasive macroadenomas had high POMC plasma levels, between 240 and 4200 U/ml (concomitant ACTH plasma levels between 77 and 5730 pg/mL); 35 patients, including one with an invasive macroadenoma, had undetectable POMC plasma levels (concomitant ACTH plasma levels between 31 and 2820 pg/mL). Among 20 patients with histologically proven ectopic ACTH syndrome, 16 had high POMC plasma levels, between 80 and 8000 U/mL (concomitant ACTH plasma levels between 45 and 9265 pg/mL); all those tumors were malignant, and the highest POMC/ACTH plasma levels ratios (taken as an index of altered POMC processing) were observed in the 3 patients with small cell carcinomas of the lung; in one of these patients, ACTH and POMC plasma levels both decreased during the course of chemotherapy, in parallel with the reduction of the tumoral mass. Four patients with ectopic ACTH syndrome had undetectable POMC plasma levels (concomitant ACTH plasma levels between 78 and 335 pg/mL): they were all typical bronchial carcinoids. These data show that high POMC plasma level is neither specific for nor constant in ectopic ACTH syndrome. Rather it should be considered as a marker of tumor aggressivity, in pituitary- and non-pituitary tumors. Its diagnostic help appears limited for the most frequent cause of occult ectopic ACTH syndrome, the typical bronchial carcinoids.

[Laboratory monitoring of therapy in Addison's disease]

Views on the usefulness of monitoring of substitution therapy in Addison's disease by hormonal laboratory indicators are controversial. The authors analysed the problem therefore in a group of 20 of their own patients. It was revealed that the adequacy of substitution of the cortisol deficiency can be very readily evaluated by diurnal profiles of cortisolaemia. The values of plasma ACTH provided less information, but were not unreliable. Assessment of free urinary cortisol did not prove useful. The adequacy of substitution of aldosterone deficiency reflected sensitively the plasma renin activity.

CONCLUSIONS

monitoring by hormonal indicators is useful, basic means are the diurnal profile of cortisolaemia and the plasma renin activity.

Hyper-adrenocorticotropinemia in a patient with Addison's disease after treatment with corticosteroids

A 40-year-old man with Addison's disease due to adrenal tuberculosis retained high levels of adrenocorticotropic hormone (ACTH) after conventional hydrocortisone replacement. Plasma ACTH levels were completely suppressed by usual replacement with hydrocortisone (20 mg at 8:00 and 10 mg at 21:00) but rebounded to abnormally high levels the following morning. Administration of 2 mg or 8 mg of dexamethasone suppressed ACTH and cortisol. Magnetic resonance imaging of the brain showed a low-intensity lesion of the pituitary gland. Pituitary hyperplasia or microadenoma with preserved regulation of ACTH was considered to be the cause of the high plasma ACTH levels. The combination of hydrocortisone and dexamethasone reduced plasma ACTH levels.

Atrial natriuretic peptide and plasma renin levels in assessment of mineralocorticoid replacement in Addison's disease

Assessment of mineralocorticoid replacement therapy in Addison's disease relies on clinical features and laboratory measurements, including plasma renin and potassium. Previous studies have questioned the value of measuring the plasma renin concentration (PRC), particularly in the setting of fludrocortisone overreplacement. The aim of this study was to evaluate the usefulness of plasma atrial natriuretic peptide (ANP) measurements as a marker of sodium and volume status in Addison's disease. Fourteen patients with Addison's disease receiving their usual glucocorticoid doses were placed on various doses of fludrocortisone (FC; 0 mg, 0.05 mg, 0.1 mg and 0.2 mg) in random order for four 2-week periods. At the end of each period, blood pressure and clinical symptoms were assessed, and blood was drawn for measurement of PRC and ANP levels. PRC was significantly elevated in patients receiving placebo (54.2 +/- 57.9 ng/mL x h) compared with PRC in those receiving baseline FC (24.7 +/- 42.4 ng/mL x h), 0.1 mg FC (15.2 +/- 25.9 ng/mL x h), and 0.2 mg FC (5.5 +/- 5.7 ng/mL x h). ANP levels were measured by either an extraction method (ANP(ext)) or directly from plasma (ANP(dir)). ANP(dir) was significantly elevated at 0.2 mg FC (87.1 +/- 20.1 pg/mL) compared with baseline (63.3 +/- 8.1 pg/mL), placebo (56.1 +/- 5.5 pg/mL), 0.05 mg FC (60.5 +/- 16.0 pg/mL), and 0.1 mg FC (65.4 +/- 13.7 pg/mL) values. ANP(ext) was elevated in patients receiving 0.2 mg FC (42.7 +/- 41.8 pg/mL) compared with that in patients receiving placebo (7.9 +/- 5.4 pg/mL), 0.05 mg FC (16.2 +/- 11.2 pg/mL), or 0.1 mg FC (19.7 +/- 11.1 pg/mL). Our data suggest that PRC is of value in determining mineralocorticoid underreplacement, whereas ANP is a more sensitive index of FC overreplacement. ANP levels may, therefore, be complementary to PRC in adjustment of mineralocorticoid doses in the upper dose range, where clinical symptoms and signs appear to be of little value.

Pituitary macroadenoma in Addison's disease

Long-standing primary failure of pituitary-dependent endocrine glands may lead to hyperplasia of the pituitary cells. These changes in the pituitary gland may be correlated with the severity and duration of target-endocrine gland insufficiency. Production of adrenocorticotrophic hormone by the pituitary tumour and modest hyperprolactinaemia may develop due to adrenocortical insufficiency, but production of prolactin by the pituitary tumour due to primary adrenal insufficiency is rare. A case study is presented, with primary adrenal insufficiency associated with hyperprolactinaemia and pituitary macroadenoma (most probably prolactinoma). Plasma levels of prolactin were found to decrease after glucocorticoid, mineralocorticoid and bromocriptine therapy.

Atypical Addison's disease in the dog: a retrospective survey of 14 cases

Fourteen dogs diagnosed with Addison's disease and having atypical serum electrolyte levels are described. Seventy-eight percent were female, and most showed signs of inappetence, weakness, or vomiting. Ninety-three percent of the cases had either hyponatremia without hyperkalemia or normal serum electrolyte concentrations. Hemogram features were variable and were not useful in suggesting a diagnosis of hypoadrenocorticism. The results of this study show that normal or mild serum electrolyte changes in a dog with clinical signs compatible with Addison's disease should not exclude this diagnosis from consideration. Definitive diagnosis depends on the demonstration of inadequate adrenocortical response to adrenocorticotropic hormone (ACTH) stimulation.

X-linked adrenoleukodystrophy is a frequent cause of idiopathic Addison's disease in young adult male patients

X-Linked adrenoleukodystrophy (ALD) is a genetic disease associated with demyelination of the central nervous system, adrenal insufficiency, and accumulation of very long chain fatty acids in tissue and body fluids. ALD is due to mutation of a gene located in Xq28 that encodes a peroxisomal transporter protein of unknown function. The most common phenotype of ALD is the cerebral form (45%) that develops in boys between 5-12 yr. Adrenomyeloneuropathy (AMN) involves the spinal cord and peripheral nerves in young adults (35%). Adrenal insufficiency (Addison's disease) is frequently associated with AMN or cerebral ALD and may remain the only clinical expression of ALD (8% of cases). The prevalence of ALD among adults with Addison's disease remains unknown. To evaluate this prevalence, we performed biochemical analysis of very long chain fatty acids in 14 male patients (age ranging from 12-45 yr at diagnosis) previously diagnosed as having primary idiopathic adrenocortical insufficiency. In 5 of 14 patients (35%), elevated plasma concentrations of very long chain fatty acids were detected. None of these patients had adrenocortical antibodies. By electrophysiological tests and magnetic resonance imaging it was determined that two patients had cerebral ALD, one had adrenomyeloneuropathy with cerebral involvement, and two had preclinical AMN. Our data support the hypothesis that ALD is a frequent cause of idiopathic Addison's disease in children and adults.

Acute adrenal insufficiency: a new presentation of Castleman's disease

We report the case of a 35-year-old patient who presented with acute adrenal insufficiency, then developed fever, hypoalbuminuria, anasarca, thrombocytopaenia and anaemia. Lymphadenopathy appeared later with microscopic features typical of Castleman's disease. Clinical remission followed treatment with intravenous immunoglobulin. Circulating interleukin-6 levels were elevated initially but were normal after immunoglobulin therapy. We surmise that high circulating levels of interleukin-6 (and ACTH) may have induced haemorrhagic necrosis of the adrenal glands and accounted for the constitutional symptoms.

Technetium-99m pentavalent dimercaptosuccinic acid imaging in patients with pituitary adenomas

We studied the tumor-seeking agent technetium-99m-labeled pentavalent dimercaptosuccinic acid ([99mTc](V)DMSA) to visualize 21 growth hormone (GH)-, nine prolactin (PRL)-, two mixed GH/PRL-, six adrenocorticotrophin (ACTH)-secreting and 15 clinically non-functioning pituitary adenomas, three craniopharyngiomas and one dysgerminoma of the sella. All non-adenomas and 31 out of 53 adenomas were studied before treatment: 22 after surgery and/or radiotherapy. Eight cases of acromegaly were studied before and after chronic treatment with octreotide, whereas three cases of acromegaly, one of prolactinoma and two of non-functioning adenoma were imaged before and after adenomectomy. As a control group, 27 patients without any clinical evidence of pituitary adenoma were studied: 10 of them were operated on previously and treated with iodine-131 for metastatic thyroid carcinoma, 10 had brain tumors and the remaining seven patients had functional pituitary hypersecretion (four Klinefelter's syndrome, two primary hypothyroidism and one Addison's disease). The scintigraphy was repeated after testosterone in Klinefelter's syndrome, L-thyroxine in primary hypothyroidism and cortisone administration in Addison's disease. Seventeen GH-secreting (81%), seven PRL-secreting (78%), three ACTH-secreting (50%), 15 non-functioning (100%) and one (50%) mixed adenoma significantly concentrated [99mTc](V)DMSA, showing elevated tumor-to-background (T/B) ratios. The T/B ratios were similar in untreated and surgically treated adenomas (11.2 +/- 5.6 vs 11.8 +/- 6.2). Radiotherapy significantly lowered the [99mTc](V)DMSA uptake to 5.1 +/- 2.8 (p < 0.1 vs untreated patients). Non-adenomatous lesions of the sella turcica did not concentrate [99mTc](V)DMSA in the pituitary as well as brain tumors and 8 out of 10 metastatic thyroid cancers. The treatment with octreotide normalized GH and insulin-like growth factor I levels and reduced [99mTc](V)DMSA from 15.7 +/- 4.8 to 13.5 +/- 3.9 (p < 0.05). Conversely, adequate substitutive therapy completely inhibited the uptake of the radiotracer in Klinefelter's syndrome, in primary hypothyroidism and in Addison's disease. The [99mTc](V)DMSA scintigraphy showed an overall sensitivity of 81% (43/53) in detecting pituitary adenomas, which was increased to 95% for lesions greater than 10 mm in size. High-quality images with minimal total body radiation were obtained, enabling a good in vivo characterization of viable adenomatous tissue as well as an accurate monitoring of the effects of different therapeutic regimens.

Plasma catecholamines in patients with Addison's disease

BACKGROUND AND OBJECTIVE

Two endocrine tissues are present within the adrenal gland: the steroid producing cortical cells and the catecholamine producing chromaffin cells. Glucocorticoids occur in high concentrations in the adrenal medulla. In vitro, glucocorticoids have been shown to induce the enzyme phenyl-N-methyl-transferase which is necessary for the production of adrenaline in adrenal medullary cells. The purpose of this study was to evaluate the possible significance of a local glucocorticoid effect on adrenomedullary function.

DESIGN

Plasma catecholamine levels were measured in patients with autoimmune Addison's disease where local production of corticosteroids is deficient in the presence of intact chromaffin tissue.

MEASUREMENTS

Catecholamines were measured by high pressure liquid chromatography and ACTH, renin and adrenal steroids by radioimmunoassay.

PATIENTS

Nineteen Addisonian patients (9 females, 10 males) were treated according to a standard regime with oral cortisone acetate (37.5 mg/day) and fludrocortisone (0.1 mg/day). All patients were clinically well.

RESULTS

Mean plasma adrenaline in patients with Addison's disease was significantly reduced compared to a sex and age matched control group (males (n = 10) 143 +/- 36 pmol/l, controls (n = 27) 303 +/- 30 pmol/l, P < 0.01; females (n = 9) 77 +/- 25 pmol/l, controls (n = 27) 293 +/- 21 pmol, P < 0.001). The noradrenaline:adrenaline ratio was clearly higher in patients with Addison's disease (males 24 +/- 4, controls 9 +/- 1, P < 0.01; females 45 +/- 6, controls 9 +/- 1, P < 0.01).

CONCLUSION

We conclude that the physiologically high local glucocorticoid concentration may be responsible for normal adrenaline production under basal conditions.

Adrenocortical insufficiency in Rhodesian sleeping sickness is not attributable to suramin

Suramin, a polysulphonated naphthylurea used in the treatment of human African trypanosomiasis (HAT), is known to cause adrenocortical insufficiency in doses exceeding the quantity used for treatment of HAT. We have previously reported that Trypanosoma brucei rhodesinese infection causes a combined central and peripheral adrenal insufficiency. To evaluate whether suramin therapy acts as an additional adrenotoxic factor, we assessed adrenocortical function in 72 patients suffering from HAT at different times during treatment with either suramin or melarsoprol by a rapid adrenocorticotropic hormone test. We found a significantly diminished peak cortisol response to stimulation in the acutely ill patients (P = 0.001), indicating impaired adrenocortical function, as well as a high incidence of partial adrenocortical insufficiency (27%). During and after trypanocidal therapy the incidence of partial adrenal insufficiency gradually declined (to 25% and 18% respectively). Stimulated peak cortisol levels did not differ significantly between patients receiving suramin and those given melarsoprol. No correlation was found between serum suramin concentration and the cortisol response to stimulation (r = 0.09, P = 0.47). Thus we conclude that suramin in trypanocidal doses neither causes nor worsens the adrenocortical dysfunction observed in Rhodesian HAT.

Reciprocal relationship between the level of circulating cortisol and growth hormone secretion in response to growth hormone-releasing hormone in man: studies in patients with adrenal insufficiency

The aim of our study was to elucidate the relationship between the level of circulating cortisol and the GH responsiveness to GHRH in six hypoadrenal patients (one male and five females; age range, 35-67 yr; body mass index range, 18-31 kg/m2). Twenty-four hours after taking the last dose of replacement therapy, each patient underwent the following experimental trials on nonconsecutive days: 1) saline, and 2) 12.5 mg, or 3) 25 mg, or 4) 250 mg hydrocortisone hemisuccinate in 250 mL saline constant iv infusion from 0-180 min. On each occasion, 1 micrograms/kg human GHRH-(1-29)NH2 was injected as an iv bolus at 60 min. During GHRH and saline infusion, serum cortisol levels were always less than the detection limit of the assay (55 nmol/L). During 12.5-, 25-, and 250-mg hydrocortisone infusions (from 15-180 min), serum cortisol averaged 413.8 +/- 19.3, 772.5 +/- 46.9, and 1520.2 +/- 110.4 nmol/L, respectively. The GH peaks after GHRH treatment during the various infusions of hydrocortisone were compared to the GH peaks observed after saline, which were normalized to 100% in each subject. GH peaks after GHRH and 25 mg hydrocortisone (70 +/- 11%) and GHRH and 250 mg hydrocortisone (69 +/- 7%) were significantly (P < 0.05) lower than the GH peaks after GHRH and saline or GHRH and 12.5 mg hydrocortisone (83 +/- 15%). No significant differences were observed between the GH peaks after GHRH and 12.5 mg hydrocortisone or GHRH and saline. Our data demonstrate that in hypoadrenal patients, the acute absence of circulating cortisol does not impair the GH secretory response to GHRH with respect to the eucortisolemic state. Moreover, our data suggest that 700 nmol/L is the approximate threshold serum cortisol concentration above which a decrease in the GH responsiveness to GHRH is observed in humans. Further increases in serum cortisol levels above this threshold value do not cause a proportional decrease in the GH responsiveness to GHRH.

Corticotropin-releasing factor-binding protein concentrations in plasma of patients with hypothalamic-pituitary-adrenal disorders

Immunoreactive corticotropin-releasing factor-binding protein (CRF-BP) concentrations in human plasma were determined by means of radioimmunoassay for human CRF-BP. CRF-BP antiserum to the C-terminal fragment of human CRF-BP (298-322) was produced, and CRF-BP (298-322) was used as the tracer and the standard. Large amounts of human CRF did not affect measurement of plasma CRF-BP with this radioimmunoassay. The basal plasma CRF-BP concentration in normal subjects was 4.19 +/- 0.57 nmol/L (mean +/- SD). The CRF-BP concentration was low in patients with Cushing's syndrome, except those with preclinical Cushing's syndrome, and high in patients with Addison's disease, hypopituitarism and isolated ACTH deficiency. After surgery, the plasma CRF-BP concentration in patients with Cushing's syndrome rose, peaked, and then decreased to the control level. In patients with Addison's disease, the high plasma CRF-BP concentration decreased to the control level after hydrocortisone replacement, the same as plasma ACTH concentration. These findings suggest that the immunoreactive CRF-BP concentration in human plasma was decreased by glucocorticoids, at least under chronic conditions.

Desoxycorticosterone pivalate in the management of canine primary hypoadrenocorticism

Primary hypoadrenocorticism in dogs may be poorly responsive to oral fluorocortisone treatment. Desoxycorticosterone pivalate is a suggested alternative treatment in these and all other cases of hypoadrenocorticism. Primary hypoadrenocorticism was diagnosed in a 3-year-old Cocker Spaniel bitch. Treatment with oral fluorocortisone at a dose rate of 0.13 mg 5 kg-1 d-1 was ineffective at maintaining serum electrolyte concentrations within normal limits. Administration of DOCP at a dose of 1.6-2.2 mg kg-1 intramuscularly every 28 d over a 5-year period, successfully maintained normal serum sodium and potassium concentrations. Side-effects encountered were minimal and were dose- or disease-related.