Adrenal function evaluation in critically ill dogs with low doses of synthetic ACTH / Avaliação da função adrenal em cães portadores de doenças críticas com baixa dose de ACTH sintético

The hypothalamus-pituitary-adrenal axis function may be impaired in patients with critical illnesses, especially cases of sepsis, named critical illness-related corticosteroid insufficiency (CIRCI). This study examined the function of the hypothalamic-pituitary-adrenal axis in normal dogs (n = 10) and dogs with critical diseases (n = 16), through determinations of endogenous ACTH (adrenocorticotropic hormone), basal cortisol and cortisol after stimulation in low doses of synthetic ACTH (1.0µg/kg/IV). The stimulation test with ACTH dose tested was verified as effective for evaluation of adrenal function in healthy and sick dogs. Ill dogs differed from healthy dogs by presenting higher basal cortisol values. Eight sick dogs presented a decrease in endogenous ACTH, basal cortisol, or Δ-cortisol. No significant differences were found between the control groups and critically ill dogs for the values of endogenous ACTH, cortisol after stimulation or Δ-cortisol. We concluded that the stimulation test with low-dose ACTH was effective for evaluation of adrenal function, as well as the fact that a considerable portion of critically ill dogs studied here, especially with sepsis, had evidence of inadequate corticosteroid response to stress.(AU)

A função do eixo hipotálamo-hipófise-adrenal pode estar comprometida em pacientes com doenças críticas, em especial casos de sepse, sendo nomeada de Insuficiência Corticosteroide Relacionada à Doença Crítica (ICRDC). O presente trabalho analisou a função do eixo hipotálamo-hipófise-adrenal em cães normais (n=10) e cães portadores de doenças críticas (n=16), por meio de determinações de ACTH (hormônio adrenocorticotrófico) endógeno, de cortisol basal e de cortisol após estímulo com baixa dose de ACTH sintético (1,0µg/kg/IV). Constatou-se que o teste de estimulação com ACTH na dose testada se mostrou eficaz para avaliação da função adrenal em cães sadios e doentes. Os cães doentes diferiram dos sadios ao apresentar valores maiores de cortisol basal. Oito cães doentes apresentaram diminuição do ACTH endógeno, do cortisol basal ou do Δ-cortisol. Não foram encontradas diferenças significativas entre os grupos Controle e Criticamente enfermos para os valores de ACTH endógeno, cortisol após estimulação ou Δ-cortisol. Concluiu-se que o teste de estimulação com baixa dose de ACTH mostrou-se eficaz para avaliação da função adrenal, assim como, uma parcela considerável da população de cães críticos aqui estudados, em especial com sepse, apresentaram evidências de resposta corticosteroide inadequada frente ao estresse.(AU)

Uso de baixa dose de ACTH sintético no teste de estimulação da função adrenal para o diagnóstico e controle do hiperadrenocorticismo canino: avaliação da eficácia diagnóstica / Use of low-dose of synthetic ACTH in the adrenal stimulation test for diagnosis and monitoring of canine hyperadrenocorticism: evaluation of diagnostic efficacy

O teste de estimulação com ACTH é o teste de escolha para realizar o controle dos valores de cortisol endógeno em pacientes sob tratamento para o hiperadrenocorticismo canino, podendo ser utilizado também para diagnosticar a doença. Os protocolos atuais utilizam doses que variam entre 5ug/kg a 250ug/animal por administração intravenosa ou intramuscular. Não se constatam estudos com doses menores que as de 5ug/kg em pacientes portadores de hiperadrenocorticismo. No presente estudo, foi testada a dose de 1ug/kg/IV; comparada à dose consagrada de 5ug/kg/IV, em grupos de animais suspeitos de HAC (HAC Diag), animais portadores de HAC e em tratamento (HAC Control) e animais sadios (Sadios). Na dose de 1ug/kg/IV, os valores basais de cortisol dos Sadios foram iguais à média 2,40ug/dL(+/-1,57ug/dL), dos HAC control foi de média 1,53ug/dL(+/-0,93,ug/dL) e dos HAC diag foi média 3,37ug/dL(+/-1,57ug/dL). Os valores pós-ACTH na dose de 1ug/kg foram de média 11,43ug/dL(+/-2,46ug/dL) para animais sadios, 2,67ug/dL(+/-1,39ug/dL) para o grupo HAC Control e média 16,56ug/dL(+/-7,62ug/dL) para o grupo HAC Diag. Os valores basais de cortisol na dose de 5ug/kg foram 0,89ug/dL(+/-0,23ug/dL) para o grupo HAC Control; média 3,08ug/dL(+/-1,99 ug/dL) para o grupo HAC Diag. Os valores pós-ACTH na dose de 5ug/kg foram de média 3,71ug/dL(+/-1,57ug/dL), para o grupo HAC control e média 22,52ug/dL (+/-8,75ug/dL) para o grupo HAC diag. Analisando-se os resultados obtidos, constatou-se que as doses 1 e 5ug/kg de ACTH sintético não diferem entre si, promovendo o mesmo tipo de variação nos valores de cortisol (ANOVA; p=0,225). Também, que a dose de 1ug/kg de ACTH foi igualmente eficaz na elevação dos níveis de cortisol nos três grupo testados (Sadios, HAC Control e HAC Diag; ANOVA, p<0,05). E, pelo teste de Dunn observamos que o grupo HAC control apresenta Δ-cortisol (delta =diferença entre cortisol após estimulo e o cortisol basal) significativamente menor que o dos grupos diagnóstico (p<0,05) e animais sadios (p<0,05). Concluiu-se que a dose de 1ug/kg de ACTH sintético pode ser utilizada com eficácia para a realização do teste de estimulação com ACTH.(AU)

ACTH stimulation is the gold standard test to monitor levels of endogen control of patients under treatment for canine hyperadrenocorticism and it may also be used to diagnose the disease. Current protocols use doses ranging from 5ug/kg to 250ug per animal by intravenous or intramuscular administration. There are no studies with doses inferior to 5ug/kg in adrenopatic patients. In the present investigation, the dose of 1ug/kg/IV was tested; compared with the recommended dose of d 5ug/kg/IV in groups of dogs under clinical suspicion of HAC (HAC Diag), animals under treatment for HAC (HAC Control) and healthy animals (Healthy). Under the dose of 1ug/kg/IV, average results for baseline cortisol values were equal to 2.40ug/dL(+/- 1.57ug/dL) for healthy, 1.53g/dL(+/-0.93ug/dL) for HAC Control and 3.37ug/dL(+/-1.57ug/dL) for HAC Diag. Post-ACTH values in the dose of 1ug/kg were average 11.43ug/dL(+/-2.46ug/dL) for healthy animals, 2.67ug/dL (+/-1.39ug/dL) for HAC Control and 16.56ug/dL(+/-7.62ug/dL) for HAC Diag group. Basal cortisol values at a dose of 5ug/kg were 0.89ug/dL (+/-0.23ug/dL) Control group for HAC; average 3.08ug/dL (+/-1.99ug/dL) for HAC Diag group. Baseline cortisol under the dose of 5ug/kg were average 3.71ug/dL(+/-1.57ug/dL) for HAC Control and 22.52g/dL(+/-8.75ug/dL) for HAC diag. Based on the present results, it was found that both doses of 1 and 5ug/kg of synthetic ACTH do not differ, providing the same kind of change in cortisol values (ANOVA, p=0.225). Also, the dose of 1ug/kg of ACTH was equally effective in raising levels of cortisol in the three groups tested (Healthy, HAC and HAC Control Diag; ANOVA, p<0.05). Through the Dunn test it was observed that HAC Control presented HAC-Δ cortisol (delta = difference between cortisol after stimulation and basal cortisol) significantly lower than HAC Diag (p<0.05) and healthy animals (p<0.05). Therefore the dose of 1ug/kg of synthetic ACTH can be effectively used to perform the ACTH stimulation test effectively.(AU)

Aldosterone secretion in patients with septic shock: a prospective study / Secreção de aldosterona em pacientes com choque séptico: estudo prospectivo

OBJECTIVE: To assess serum levels of the main factors that regulate the activation of the zona glomerulosa and aldosterone production in patients with septic shock, as well as their response to a high-dose (250 µg) adrenocorticotropic hormone (ACTH) stimulation test. SUBJECTS AND METHODS: In 27 patients with septic shock, baseline levels of aldosterone, cortisol, ACTH, renin, sodium, potassium, and lactate were measured, followed by a cortrosyn test. RESULTS: Renin correlated with baseline aldosterone and its variation after cortrosyn stimulation. Baseline cortisol and its variation did not correlate with ACTH. Only three patients had concomitant dysfunction of aldosterone and cortisol secretion. CONCLUSIONS: Activation of the zona glomerulosa and zona fasciculata are independent. Aldosterone secretion is dependent on the integrity of the renin-angiotensin-aldosterone system, whereas cortisol secretion does not appear to depend predominantly on the hypothalamic-pituitary-adrenal axis. These results suggest that activation of the adrenal gland in critically ill patients occurs by multiple mechanisms.

OBJETIVO: Avaliar os níveis séricos dos principais fatores que regulam a ativação da zona glomerulosa e a produção de aldosterona em pacientes com choque séptico, assim como sua resposta ao teste de cortrosina em alta dose (250 µg). SUJEITOS E MÉTODOS: Em 27 portadores de choque séptico, foram aferidos níveis basais de aldosterona, cortisol, ACTH, renina, sódio, potássio e lactato, bem como realizado teste de cortrosina. RESULTADOS: Renina se correlacionou com níveis basais de aldosterona e sua variação após teste de cortrosina. Cortisol basal e sua variação não se correlacionaram com ACTH. Apenas três pacientes apresentaram disfunção concomitante da secreção de aldosterona e cortisol. CONCLUSÕES: Ativação das zonas fasciculada e glomerulosa são independentes. Secreção de aldosterona é dependente da integridade do sistema renina-angiotensina-aldosterona, enquanto secreção de cortisol não parece predominantemente dependente do eixo hipotálamo-hipófise-adrenal. Esses resultados sugerem que a ativação da adrenal em pacientes críticos ocorre por múltiplos mecanismos.

Ovarian intratumoral 21-hydroxylase deficiency in a postmenopausal hirsute woman / Deficiência de 21-hidroxilase ovariana intratumoral na virilização da mulher pós-menopausa

Virilising ovarian tumours are a rare cause of hyperandrogenism in women, accounting for less than 5% of all ovarian neoplasms. It occurs most often in - and postmenopausal women. We report a case of a 64 year-old woman with signs of virilisation that had started 3 years before. Blood hormone analysis revealed increased levels of testosterone, and 17-hydroxyprogesterone. The tetracosactin test revealed 21-hydroxylase deficiency. Radiological imaging demonstrated a nodule in her left ovary. The patient was submitted to bilateral laparoscopic oophorectomy, and histopathological examination revealed a luteoma of the left ovary. Postoperative serum testosterone level and 17-hydroxyprogesterone returned to normal levels in one month. Virilism regressed within six months. Our patient also showed an elevation in 17-OHP serum levels. Normalization of 17-OHP after oophorectomy suggests a case of intratumoral 21-hydroxylase deficiency. To our knowledge, this is the first description of ovarian intratumoral 21-hydroxylase deficiency in a postmenopausal woman. Arq Bras Endocrinol Metab. 2012;56(9):672-6.

Tumores ovarianos virilizantes são uma causa rara de hiperandrogenismo em mulheres, contabilizando menos de 5% de todos as neoplasias ovarianas. Esses tumores ocorrem mais comumente em mulheres em peri ou pós-menopausa. Relatamos aqui o caso de uma mulher de 64 anos de idade com sintomas de virilização que começaram 3 anos antes. O perfil hormonal revelou níveis aumentados de testosterona e de 17-hidroxiprogesterona (17-OHP). O teste de tetracosactin demonstrou deficiência de 21-hidroxilase. Exames radiológicos mostraram um nódulo no ovário esquerdo. A paciente foi submetida à ooforectomia laparoscópica bilateral e o exame histopatológico revelou um luteoma no ovário esquerdo. A concentração sérica de testosterona e de 17-hidroxiprogesterona após a cirurgia retornou aos níveis normais em um mês. A virilização regrediu em 6 meses. Nossa paciente também revelou uma elevação dos níveis séricos de 17-OHP. A normalização da 17-OHP após a ooforectomia sugere um caso de deficiência de 21-hidroxilase intratumoral. Esta é a primeira descrição de deficiência de 21-hidroxilase intratumoral em uma mulher na pós-menopausa. Arq Bras Endocrinol Metab. 2012;56(9):672-6.

Diagnosis of adrenal failure in critically ill patients / Diagnóstico de insuficiência adrenal em pacientes críticos

In the last two decades there was important evolution on the knowledge of the function of the hypothalamic-pituitary-adrenal axis. In the last decade, the expression "relative adrenal insufficiency" (RAI) was created, and more recently "critical illness-related corticosteroid insufficiency" (CIRCI) was used to designate those patients in which cortisol production was not sufficiently increased in stress situations. Patients with CIRCI have elevated hospital morbidity and mortality. Currently, there is a wide discussion about diagnostic criteria for this dysfunction. Besides basal cortisol, some publications now study the role of other tests, such as cortrosyn test - either in low (1 μg) or high doses (250 μg); free cortisol, salivary cortisol, metyrapone test and others. With this review, we aimed at summarizing the results of the most influent papers that intended to define diagnostic criteria for CIRCI. We also suggest an approach for CIRCI diagnosis and make it clear that the decision about steroid therapy in septic shock patients is matter apart from RAI.

Nas últimas décadas, houve uma importante evolução no conhecimento sobre a função do eixo hipotálamo-pituitária-adrenal. Na última década, foi cunhada a expressão "insuficiência adrenal relativa" (IAR) e, mais recentemente, a expressão "insuficiência adrenal relacionada à doença grave" (CIRCI) foi utilizada para designar aqueles pacientes nos quais a produção de cortisol não era suficientemente elevada em situações de estresse. Pacientes com CIRCI apresentam elevada morbidade e mortalidade em hospitais. Atualmente, há uma ampla discussão sobre os critérios de diagnóstico para essa desordem. Além do cortisol basal, algumas publicações analisaram o papel de outros testes, tais como o teste de estímulo com ACTH (cortrosina), com doses baixas (1 mg) ou altas (250 mg), cortisol livre, cortisol salivar, teste da metirapona e outros. O objetivo desta revisão foi resumir os resultados dos artigos mais importantes que buscaram definir os critérios de diagnóstico para a CIRCI. Também sugerimos uma abordagem para o diagnóstico da CIRCI e deixamos claro que a decisão sobre a terapia com esteroides em pacientes em choque séptico é uma questão separada da IAR.

Comparison of low dose short synacthen test [1 microgram] with standard dose short synacthen test [250 microgram] in patients of adrenal insufficiency

To determine the diagnostic accuracy of low dose 1 microg short synacthen test taking standard dose 250 microg short synacthen test as gold standard. A descriptive study. Department of Chemical Pathology and Endocrinology Armed Forces Institute of Pathology Rawalpindi from Jan 2006 to Jan 2007. Thirty patients with clinical suspicion of adrenal insufficiency and equal number of age matched healthy males and females as controls were included in the study. Relevant clinical history and physical examination was recorded on designated proforma. Short synacthen test was performed between 0800 - 1000 h by using ACTH doses of 1 microg and 250 microg with interval of 3 days in all patients and controls. Three blood samples were obtained for cortisol [basal, 30 min and 60 min after l/M ACTH injection]. Using 250 microg short synacthen test as a standard test, the 1 microg short synacthen test had sensitivity of 100%, specificity of 72%, positive predictive value of 71% and negative predictive value of 100% and 83% accuracy. The low dose 1 microg short synacthen test is as sensitive as standard dose 250 microg short synacthen test but less specific in the diagnosis of adrenal insufficiency

Prueba de cosintropina en tuberculosis activa grave / Cosyntropin test in severe active tuberculosis

BACKGROUND: Frequency of adrenal insufficiency in patients with tuberculosis varies from 0 to 58%; however, all published series excluded severely ill patients. Our objective was to investigate adrenal insufficiency with the low-dose cosyntropin test in patients with severe active tuberculosis. METHOD: From two large university affiliated hospitals, 18 patients with tuberculosis and criteria of sepsis or severe sepsis according to SCCM/ACCP criteria, defined by the present authors as severe active tuberculosis, participated in the study. A low-dose ACTH test with 10 mg of ACTH was performed. After ACTH test, all patients received a stress dose of hydrocortisone (240 mg/day) during their entire hospitalization along with four antituberculous drugs. Abnormal response was considered when elevation of serum cortisol was <7 microg/dl with respect to basal level, 60 min after ACTH administration. RESULTS: Adrenal insufficiency was found in seven patients (39%); no clinical or laboratory data were associated with the presence of abnormal adrenal response. Except in one patient with HIV infection, all the signs and symptoms improved after antituberculous and hydrocortisone treatment. The increment in serum cortisol value post-ACTH test was lower in patients with hypoalbuminemia. CONCLUSIONS: Adrenal insufficiency is frequent in severe active tuberculosis. The efficacy and security of supplemental steroid treatment in severe active tuberculosis should be established by a randomized clinical trial.

New concepts in treatment of post-dural puncture headache: Tetracosactide vs. tetrazepam

We investigated the effect of tetracosactide hexa-acetate vs tetrazepam as therapeutic agent for treatment of post-dural puncture headache [PDPH]. Thirty patients with PDPH were randomly allocated to receive either tetracosactide 1 mg IM [group A, n=15] or oral tetrazepam 1.2 mg/kg [group B, n=15]. Severity of headache [VAS scale], neck rigidity, nausea and vomiting were recorded before treatment and at intervals after treatment. The need for supplementary management as hydration, analgesics or epidural blood patch was also recorded. Our results suggest that tetrazepam has a superior effect compared to tetracosactide in controlling PDPH. It also alleviates neck rigidity and vomiting in a statistically significant way. The drug is also cheap, easy to use and has minimal side effects

Plasma cortisol response to 1-24 adrenocorticotropin in patients with treated/untreated sellar & suprasellar mass lesions.

BACKGROUND & OBJECTIVES: One microgram short synacthene test is widely recommended as a screening test for evaluation of hypothalamo-pituitary-adrenocortical axis in patients with secondary adrenal insufficiency. Information on adequacy of cortisol response to this dose at different periods of the day in patients with hypothalamic-pituitary disorders is not available. Hence, this study was designed to assess the adequacy of cortisol response to 1 microg 1-24 adrenocorticotropin (ACTH) at 0800 h and 1600 h in patients with sellar and suprasellar mass lesions. METHODS: Thirty five consecutive patients with sellar and suprasellar mass lesions with mean age of 43.0+/-14.4 yr and 36 healthy controls with mean age of 32.3+/-9.0 yr were studied after obtaining informed consent. Maintenance doses of glucocorticoids in these patients were discontinued appropriately. On day 1, prestimulated and stimulated plasma cortisol samples at 0800 h and at 30 and 60 min following i.v. bolus of 1 microg 1-24 ACTH were collected. While on day 3, plasma cortisol samples were similarly collected at 1600 h. Cortisol estimation was done by a sensitive and specific radioimmunoassay. Stimulated plasma cortisol of 500 nmol/l or higher was defined as a normal response. RESULTS: In healthy controls, the prestimulated and peak cortisol levels at 0800 h (377.5+/-93.3 and 729.1+/-183.2 nmol/l) were higher (P<0.001 and P<0.01) than those at 1600 h (230.1+/-75.7 and 665.8+/-138.6 nmol/l). All subjects had a cortisol response of 500 nmol/l or higher in response to 1 microg 1-24 ACTH both at 0800 and 1600 h. In the patients' group, the prestimulated plasma cortisol at 0800 h (250.3+/-169.7 nmol/l) was higher (P<0.001) than that at 1600 h (166.3+/-128.9 nmol/l), while the peak cortisol response was comparable (P>0.05) in the morning as well as in the evening (490.9+/-309.4 vs 464.8+/-318.4). In 27 patients (77%) the morning and evening stimulated cortisol response to 1 microg 1-24 ACTH was consistent (normal in 13 and subnormal in 14) but was discrepant in the remaining 8 (23%). In 7 of these 8 patients, cortisol response was normal at 0800 h but not at 1600 h, while in only one, normal response was seen at 1600 h but not at 0800 h. INTERPRETATION & CONCLUSION: The demonstration of normal peak cortisol response to 1 microg 1-24 ACTH at 0800 h but not at 1600 h in substantial number of patients with sellar and suprasellar mass lesions suggests preference to morning for performing this test.

Effect of Inhaled Fluticasone Propionate on Hypothalamic-Pituitary-Adrenal Axis in Bronchial Asthma Patient / 결핵

BACKGROUND: Inhaled glucocorticoids are the medical treatment of choice in asthma patients. Fluticasone propionate is one of the most effective inhaled corticosteroids and has been reported to have minimal effect on the hypothalamic-pituitary-adrenal axis at the recommended dose. However, reports of long-term trials characterizing their systemic safety with chronic use are rare. This study was designed to evaluate the long-term safety of inhaled fluticasone propionate to the hypothalamic-pituitary-adrenal axis. METHOD: This study was conducted on 21 patients to evaluate the adrenal response to rapid ACTH stimulation test after 6 months of treatment with fluticasone propionate from 200 µg to 750 µg daily. The serum cortisol levels was measured to assess its effect on the hypothalamic-pituitary-adrenal axis just prior to the injection, at 30 minutes and 60 minutes after an intramuscular injection of synthetic ACTH. RESULT: The mean dose of inhaled fluticasone propionate was 355 µg per day(SD=174 µg, range=200 µg to 750 µg). The mean serum cortisol levels of the patients was 11.0 µg/dl(SD=6.4 µg/dl) prior to the injection, 20.0 µg/dl(SD=7.7 µg/dl) after 30 minutes, and 23.0 µg/dl(SD=6.3 µg/dl) after 60 minutes. Sixteen patients of the 21 patients had a normal response(>18 µg/dl), and 5 out of the 21 patients had serum cortisol levels below the normal range after the rapid ACTH stimulation test. CONCLUSION: Adrenal suppression occurred in 5 out of 21 patients with 6 months treatment with inhaled fluticasone propionate.

Hypothalamo-pituitary-adrenal axis function in asthmatics taking low dose inhaled beclomethasone dipropionate.

OBJECTIVES: Anti-inflammatory drugs, particularly inhaled corticosteroids remain the mainstay of treatment of bronchial asthma. However, these drugs have potential side effects. This study was undertaken to evaluate the effects of inhaled beclomethasone dipropionate (400 and 800 micrograms) over a period of six months on the hypothalamo-pituitary-adrenal axis (HPA) suppression. METHODS: Assessment of the hypothalamo-pituitary-adrenal axis function was carried out by tetracosactrin test at time zero, (before start of treatment), three months, and six months. The baseline values served as the controls for each patient. Serum cortisol was estimated by radioimmuno assay. The response to short tetracosactrin test was classified as normal if serum cortisol levels rose at least 200 nmol/L to a minimum of 500 nmol/L. RESULTS: There were seven patients who were inhaling beclomethasone dipropionate in a dose of 400 micrograms/day and another seven patients were taking the same drug in a dose of 800 micrograms/day. There was no side effect of the drug in any patient except in one patient who had dysphonia. The mean basal cortisol levels were normal in all the subjects at 0, 3 and 6 months of therapy. Tetracosactrin stimulation test was also normal in all patients at all the times who were receiving the dose of 400 micrograms/day. However, one patient (14%) receiving 800 micrograms/day had HPA axis suppression at six months. Two patients in this group also had low basal cortisol levels. There was no clinical evidence of such suppression/deficiency. CONCLUSION: Beclomethasone dipropionate in a dose of 800 micrograms/day may suppress the hypothalamo-pituitary-adrenal axis if used for long periods (six months). However, this may not have any clinical significance.

The Role of Low-dose ACTH Stimulation Test in the Diagnosis of Adrenal Insufficiency / 대한내분비학회지

BACKGROUND: Rapid adrenocorticotropin (ACTH) stimulation test using 250ug of ACTH (1-24) has been used as a standard test in the initial assessment of adrenal function. However, it has recently been suggested that a rnaximal cortisol response can be achieved with a much lower ACTH dose, and reducing the dose might further enhance the sensitivity of the test in the detection of mild adrenal insufficiency. This study was performed to evaluate the role of low-dose (lug) ACTH stimulation test in the assessment of adrenal function and the diagnosis of subtle adrenal insufficiency. METHODS: Twenty-two subjects with suspected adrenal insufficiency due to long-term corticosteroid use were included in this study. The correlations between clinical features and the serum cortisol responses to low dose (lug) and high dose (250 ug) ACTH stimulation were evaluated. RESULTS: In high dose test, 10 (67%) out of 15 subjects with clinical features of adrenal insufficiency showed decreased serum cortisol response (peak cortisol level 18ug/dL). On the other hand, 14 (93%) subjects with clinical features of adrenal insufficiency showed decreased serum cortisol response in low dose test, while only one showed normal response. In 7 subjects without clinical features of adrenal insufficiency, 5 subject (71%) showed normal response, and 2 subjects (29%) showed decreased response in both low and high dose tests. CONCLUSION: These results suggest that the 1-ug low dose ACTH stimulation test might be more sensitive than conventional 250-ug test in the detection of mild adrenal insufficiency. Further studies are needed to determine the optimal dose of ACTH and the criteria for normal response to ACTH stimulation.

Estímulo do eixo hipófise-adrenocortical com o hormônio liberador de corticotrofina (CRH) na síndrome de imunodeficiência adquirida: evidência de ativaçäo do sistema imune-neuroendócrino / Stimulus of hypophyseal-adrenocortical axis with the corticotropin releasing hormone (CRH) in acquired immunodeficiency syndrome: evidence for activation of the immune-neuroendocrine system

Portadores de AIDS podem apresentar alteraçöes primárias e/ou secundárias do eixo hipotálamo-hipofisário-adrenocortical (EHHA), com manifestaçöes clínicas que väo de crises addisonianas a quadros de hipercortisolismo. Objeto. Avaliar o EHHA de 20 pacientes de AIDS e 17 controles normais, mediante testes de estímulo com ACTH exógeno (cosintropina, 250µg IV em bolo, com dosagem de cortisol basal e 60min após) e, subseqüentemente, teste de estímulo com hormônio liberador de corticotrofina ovino sintético (oCRH, 1µg/kg IV em bolo, com dosagens de ACTH e cortisol basais e a intervalos de 15-30min durante duas horas). Resultados. Diferente dos voluntários normais, pacientes de AIDS apresentaram estado de hipercortisolismo basal e após estímulo, tanto com cosintropina como com o CRH; cortisol (em µg/dL, média + or - cosintropina - basal 22,5 + or - 7,1 x 10,6 + or - 3,6 (p < 0,01) e após estímulo, 36,0 + or - 12,8 x 28,3 + or - 7,6 (p< 0,05); teste de oCRH - basal 19,7 + or - 9,0 x 10,1 + or - 3,4 (p < 0,01) e no pico de resposta, 27,5 + or - 8,9 x 18,3 + or 0 5,1 (p < 0,05). Além disso, a secreçäo de ACTH encontrava-se também significantemente mais elevada nos pacientes de AIDS após o teste de estímulo com o CRH; ACTH (em pg/mL) nos pacientes com AIDS x normais: teste de oCRH - basal 42,2 + or - 33,5 x 28,9 + or - 12,7 (NS) e no pico de resposta, 104,7 + or - 62,2 x 59,3 + or - 17,6 (p < 0,05). Conclusöes. Pela condiçäo de estresse continuado, os pacientes de AIDS apresentam estado de hipercortisolismo e de hipersecreçäo de ACTH, revelando resistência ao mecanismo de feedback negativo. Este fenômeno pode ser explicado pela interaçäo do sistema imunológico com o EHHA, com ativaçäo deste eixo pela liberaçäo de linfocinas circulantes que estimulariam, diretamente, hipotálamo e hipófise a produzir CRH e ACTH, respectivamente