Neurodegenerative and inflammatory biomarkers in cerebrospinal fluid in patients with Cushing's syndrome in remission.

OBJECTIVE: Patients with Cushing's syndrome (CS) in long-term remission have impaired cognitive function. Cerebrospinal fluid (CSF) biomarkers are important diagnostic tools in the work-up of patients with cognitive impairment. The aim of this study was to analyze neurodegenerative and inflammatory biomarkers in the CSF of patients with CS in remission. DESIGN: A cross-sectional, single-center study. PATIENTS: Twelve women previously treated for CS and six healthy subjects. MEASUREMENTS: Neurodegenerative CSF markers: total tau, hyperphosphorylated tau, amyloid beta peptides, soluble amyloid precursor protein alpha and beta, neurofilament light proteins, glial fibrillary acidic protein, and monocyte chemoattractant protein 1; and inflammatory CSF markers: interferon gamma, interleukin (IL) 1B, IL2, IL4, IL5, IL8, IL10, IL12p70, IL13, and tumor necrosis factor alpha. RESULTS: The mean age (mean±S.D.) was similar in patients with CS in remission (44.9±14 years) and healthy subjects (42.3±15.7 years; P=0.726). No differences were observed in the concentrations of any neurodegenerative biomarkers between the patients and healthy subjects. Nor were the concentrations of inflammatory biomarkers different between the groups. CONCLUSIONS: The pattern of neurodegenerative and inflammatory biomarkers in the CSF of patients with CS in remission does not differ from that of the healthy subjects. The underlying mechanisms of the cognitive deficits in patients with CS in remission are different from those observed in patients with neurodegenerative disorders and remain to be explained.

Cerebrospinal fluid immunoreactive somatostatin concentrations in patients with Cushing's disease and major depression: relationship to indices of corticotropin-releasing hormone and cortisol secretion.

To further explore the differential effects of peripherally and centrally derived hypercortisolism on neurohormonal systems implicated in the pathophysiology of mood and cognitive disturbances, we examined the cerebrospinal fluid (CSF) concentrations of immunoreactive somatostatin (IR-SRIF) in patients with Cushing's disease and major depression and the relationship of these levels to CSF immunoreactive corticotropin-releasing hormone (CRH) concentrations and urinary free cortisol excretion. In particular, since CSF SRIF levels consistently have been shown to be reduced in depression, we wished to assess whether decreased centrally directed SRIF was more likely a primary or a secondary factor in the hypercortisolism of major depression. CSF SRIF levels were significantly reduced in 11 patients with documented Cushing's disease and in 1 patient with ectopic adrenocorticotropic hormone secretion as compared with both 41 healthy volunteers (19.4 +/- 2.9 vs. 37.4 +/- 1.5 pmol/l; p < 0.01) and 28 patients with major depression (30.2 +/- 2.4 pmol/l; p < 0.05), whose CSF SRIF levels were also significantly reduced as compared with controls (p < 0.05). CSF SRIF levels in the Cushing's disease patients correlated positively with CSF CRH (r = 0.64; p < 0.025), suggesting that either the sustained hypercortisolism in these patients and/or its suppression of central CRH secretion contributed to the reduction in SRIF. A more modest but significant correlation between CSF SRIF and CSF CRH was observed in the healthy volunteers (r = 0.37; d.f. = 37; p < 0.02); in the depressed patients, no linear relationship, but rather an inverted U-shaped relationship was found which significantly fit by a quadratic function (r2 = 0.90; d.f. = 22; p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebrospinal fluid immunoreactive corticotropin-releasing hormone and adrenocorticotropin secretion in Cushing's disease and major depression: potential clinical implications.

To explore whether possible differences in central nervous system neuromodulators contribute to the differential presentation of affective symptomatology in Cushing's disease and major depression, we examined the levels of immunoreactive CRH and ACTH in the cerebrospinal fluid (CSF) of 11 patients with Cushing's disease, a patient with ectopic ACTH secretion, 34 patients with major depression, and 60 healthy subjects. We elected to measure these peptides not only because both are classically involved in pituitary-adrenal regulation, but also because their primarily arousal-producing and anorexigenic behavioral effects in experimental animals suggest that they may play a role in the symptom complex of depressive syndromes. We also explored whether the CSF levels of these peptides were more helpful in determining the often difficult differential diagnosis between major depression and Cushing's disease than the plasma ACTH response to ovine CRH, a currently used but somewhat insensitive laboratory means of distinguishing these disorders. CSF levels of immunoreactive CRH and ACTH were significantly lower in Cushing's disease patients [21.9 +/- 2.7 and 15.4 +/- 1.8 pg/mL, (mean +/- SEM), respectively] compared to patients with major depression [38.4 +/- 2.3 pg/mL (P less than 0.01) and 24.5 +/- 1.6 pg/mL (P less than 0.01), respectively] and controls [38.4 +/- 1.6 pg/mL (P less than 0.001) and 26.3 +/- 1.1 pg/mL (P less than 0.001), respectively]. The coexistence of high plasma ACTH and low CSF ACTH in Cushing's disease yielded a CSF/plasma ACTH ratio consistently less than that in depressed patients, with only 2 of 31 subjects comprising both groups showing values that overlapped. In contrast, 9 of the combined patients showed ACTH responses to ovine CRH that overlapped. These data suggest that differences in centrally directed CRH secretion may account for the differential presentation of the dysphoric syndromes seen in major depression and Cushing's disease. Hence, the classic form of major depression (melancholia), is often associated with evidence of pathological hyperarousal, such as intense anxiety, sleeplessness, and anorexia, while that of Cushing's disease is associated with evidence of pathological hyperarousal, including hyperphagia, fatigue, and inertia. Moreover, measurement of the CSF/plasma ACTH ratio may serve as a clinically useful adjunct to the ovine CRH stimulation test and other laboratory measures in determining the differential diagnosis between major depression and Cushing's disease.

Radioimmunoassay of corticotropin-releasing hormone: methodology and clinical application.

Corticotropin-releasing hormone (CRH) levels in the human plasma and cerebrospinal fluid (CSF), and those in the rat hypothalamus, peripheral and hypophyseal portal plasma were studied by a specific h/r CRH RIA and an immunoaffinity procedure. CRH levels in the plasma and CSF were low in patients with hypercortisolemia and those with hypothalamic hypopituitarism, but high in patients with hypocortisolemia except for patients with hypothalamic hypopituitarism. Plasma CRH responded to insulin-induced hypoglycemia (ITT) those with Addison's disease and those with primary hypopituitarism, but not in patients with Cushing's syndrome or in patients with hypothalamic hypopituitarism. The results suggest that the major component of plasma CRH may be of hypothalamic origin, but other extrahypothalamic tissues cannot be ruled out as minor sources of plasma CRH. In addition, the measurement of CRH levels in the plasma and CSF seems to be of value in evaluating the hypothalamic function. The short negative feedback mechanism regulating CRH release was demonstrated in humans and rats. In the absence of the long negative feedback control of ACTH secretion by glucocorticoids, ACTH originating from the pituitary may regulate ACTH secretion form the pituitary through inhibition of CRH release.

Somatomedin levels in cerebrospinal fluid from adults with pituitary disorders.

Somatomedin levels in cerebrospinal fluid (CSF) were determined in patients with acromegaly, pituitary deficiency, prolactinoma, and Cushing's disease by radioimmunoassay (RIA) for insulin-like growth factor 1 (IGF-1) and for IGF-2 as well as a radioreceptor assay (RRA) with adult human brain plasma membranes and IGF-2 as ligand. The mean value of RIA-IGF-2 (31 +/- 1.6 ng/ml) predominated over that of RIA-IGF-1 (5.8 +/- 0.3 ng/ml), but 10 times higher levels were found by RRA-IGF-2. Patients with acromegaly were not found to have higher values than those with GH deficiency even after corrections were made for possible leakage across the blood-CSF barrier. No correlations were found between CSF somatomedin levels determined by different techniques and immunoreactive IGF-1 or GH in the peripheral circulation except for a positive correlation between CSF RIA-IGF-2 and serum IGF-1 in patients with acromegaly. These findings suggest that somatomedins in CSF consist primarily of IGF-2-like peptides which are derived from production within the central nervous system or pituitary gland rather than from transport across the blood-CSF barrier.

[Corticotropin-releasing factor concentrations in cerebrospinal fluid and its diurnal rhythm in patients with Cushing's disease].

Since Vale et al isolated and sequenced a 41 amino acid peptide with corticotropin-releasing factor (CRF) activity from ovine hypothalami, intensive works have been done about its physiological activity and intracerebral distribution. However, little has been done yet about CRF metabolism in human cerebrospinal fluid (CSF). Using a specific ovine CRF radioimmunoassay (RIA), we measured the levels of CRF in CSF from 16 patients with Cushing's disease (group I), 8 patients with Acromegaly (group II), 5 patients with Prolactinoma (group III) and 10 patients without endocrine abnormalities (group IV). Moreover diurnal changes of CRF in CSF from 2 patients with Acromegaly and 2 patients with Cushing's disease were examined. Dilution curves of CRF in CSF were parallel to that of synthetic ovine CRF standard. The intraassay coefficient of variation was 9.2% and the interassay coefficient of variation 12.6%. The concentrations of CRF in CSF of groups I, II, III and IV were 38.83 +/- 9.02 pg/ml (mean +/- SD), 44.24 +/- 4.71, 47.62 +/- 8.05 and 49.45 +/- 12.86, respectively. Group I was significantly lower than group IV (p less than 0.05). On the other hand, group II or III was not significantly different from group IV. A diurnal rhythm of CRF in CSF was observed in 2 patients with Acromegaly. However, there was almost no change in the 2 patients with Cushing's disease. In considering rich amount of CRF in hypothalamus and CRF-positive fibers surrounding the third ventricle, CRF content in CSF seems to reflect mainly its metabolic activity in hypothalamus.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunoreactive corticotropin-releasing factor concentrations in cerebrospinal fluid from patients with hypothalamic-pituitary-adrenal disorders.

The concentrations of immunoreactive corticotropin-releasing factor (I-CRF) in human cerebrospinal fluid (CSF) were measured utilizing immunoaffinity chromatography and RIA in patients with no endocrine disease, patients with Cushing's disease, Nelson's syndrome, Sheehan's syndrome, Addison's disease and steroid treated patients. On high performance liquid chromatography, the elution profile and retention time of I-CRF in CSF were not identical with ovine CRF. I-CRF concentrations in CSF from patients with Cushing's disease and Sheehan's syndrome were lower than those from normal subjects, however those from patients with Nelson's syndrome and Addison's disease were within the normal range. I-CRF concentrations in CSF from patients with Cushing's disease returned to normal levels 2-9 months after pituitary adenomectomy. These results suggest that CSF I-CRF concentrations are reduced by increased plasma corticosteroid levels.

Distribution, biosynthesis, and physiological role of corticotropin-releasing factor in the human: an overview.

Our findings to date indicate that: A peptide resembling oCRF is present in human and mammalian hypothalamus. oCRF is present in human lumbar cerebrospinal fluid. oCRF concentrations do not differ in CSF from normal individuals and from patients with Cushing's syndrome. oCRF appears to be synthesized via a large oligopeptide precursor. An oCRF-like molecule (oCRF-LI) is present in hypothalamic brain tissue. We have also observed more tentative evidence of low levels of oCRF-LI outside of the brain. oCRF is likely to be a central mediator of stress in its multiple forms. We believe that oCRF is clearly of major physiological importance, but that many critical unanswered questions remain. Probably, the most fascinating of these, which we are only beginning to comprehend, concerns the functions of CRF in extrahypothalamic brain as well as the CRF which appears to be present outside the brain.

Immunoreactive beta-endorphin and adrenocorticotropin in human cerebrospinal fluid.

To elucidate the significance of beta-endorphin in human cerebrospinal fluid (CSF), CSF levels of beta-endorphin-like immunoreactivity (beta-EP-LI) in various diseases were determined by a specific radioimmunoassay and compared with simultaneously determined ACTH-like immunoreactivity (ACTH-LI) levels in CSF. CSF beta-EP-LI and ACTH-LI in the control group, consisting of 5 normal subjects and 19 patients with nonendocrine diseases, were 22.2+/-1.3 and 14.6+/-0.4 fmol/ml, respectively. CSF levels of these peptides in patients with schizophrenia (n = 19) and acromegaly (n = 10) were not significantly different from those in the control group. Patients with Cushing's disease (n = 7) had significantly lower CSF beta-EP-LI and ACTH-LI levels than those in the control group. Four of them showed a parallel increase in CSF beta-EP-LI and CSF ACTH-LI levels after the complete removal of pituitary microadenomas (P < 0.05). Gel chromatography of CSF beta-EP-LI from a normal volunteer, a control patient, and one patient each with catatonia, Nelson's syndrome, Cushing's syndrome (adrenal adenoma), and acromegaly gave similar patterns consisting of three peaks with the elution positions comparable to those of authentic beta-endorphin, beta-lipotropin, and possibly their precursor molecule. Gel chromatographic patterns of CSF beta-EP-LI and ACTH-LI were compared in a normal volunteer. The first peaks of beta-EP-LI and ACTH-LI eluted at the same position and the second peak of ACTH-LI coincided with the elution position of authentic ACTH.CSF beta-EP-LI and ACTH-LI levels determined every 5 min over a period of 80 min in three normal volunteers did not show moment-to-moment variability.A significant correlation (r = 0.75, P < 0.001) was seen between CSF beta-EP-LI and ACTH-LI levels in normal subjects and patients studied (n = 73). This suggests that beta-endorphin and ACTH in human CSF share the common regulatory mechanism in normal and pathologic conditions.

[Measurement of methionine-enkephalin-like substance in CSF from normal subjects and patients with pituitary adenoma (author's transl)].

Methionine-enkephalin-like substance was measured in CSF by the radioreceptor-assay established by Furui et al. Samples were obtained from preoperative 20 cases, in which were included 11 cases of pituitary adenoma, 3 cases of craniopharyngioma, 2 cases of pseudtumor cerebri and 4 normal cases, by lumbar puncture. Also postoperative measurement of this substance and pre- and postoperative measurement of ACTH in plasma were performed in 5 cases of Cushing's disease. Five ml of CSF was chromatograpied on two successive columns, lyophilized and assayed for opiate receptor affinity against 3H-dihydromorphine. Measured values were expressed as methionine-enkaphalin equivalents using the displacement curve run in parellel. Methionine-enkephalin-like substance level ranged from less than 0.5 to 20.0 pmoles/ml in all cases and mean value was 2.6 pmoles/ml (+/- 1.0 S.E.) in normal subjects. In Cushing's disease the level was not elevated preoperatively (2.1 +/- 0.3) and did not significantly decrease postoperatively (1.6 +/- 0.4 pmoles/ml) in contrast to the decrease of ACTH in plasma. It is suggested that methionine-enkephalin-like substance in CSF is not derived from ACTH producing cells of pituitary gland. One case of craniopharyngioma showed very high value. This case revealed diabetes insipidus at sampling. The possibility of participation of methionine-enkephalin in secretion of antidiuretic hormone was discussed.

The concentration of cerebrospinal fluid potassium during systemic disturbances of acid-base metabolism.

A possible relationship between blood acid-base state and the concentration of cerebrospinal fluid potassium has been examined in patients with systemic disturbances of acid-base metabolism. Over the range of values studied it was not possible to demonstrate any significant correlation between these parameters.

Cerebrospinal fluid concentration and urinary excretion of cyclic adenosine-3', 5'-monophosphate in various diseases of children.

Cerebrospinal fluid (CSF) concentration and urinary excretion of cyclic adenosine-3',5'-monophosphate(cAMP) were measured in children aged from 3 days to 15 years by the protein-binding method of Gilman (1970). The mean CSF cAMP concentration (22.4 plus or minus 0.6 (S.E.) nmol/l) of 24 "healthy" children tended to be lower (P less then 0.2) than that of adult patients who revealed no pathological findings on clinical examination. No difference in the results was foung between the sexes. High cAMP concentrations were found in CSF of children suffering from cerebellar glioma, hypothalamic precocious puberty, bacterial meningitis, or Cushing's disease. The urinary excretion of cAMP varied from 0.2 to 5.3 in "healthy" and from 1.3 to 7.6 mumol/24 hrs in diseased children. Two children with pheochromocytoma showed a striking decrease in the rate of urinary excretion of the nucleotide after surgical treatment.