Autoantibodies against pituitary peptides in sera from patients with multiple sclerosis

Evaluation of the relationship between the morphometric structure of the pituitary gland and fatigue in patients with multiple sclerosis

BACKGROUND

The correlation between fatigue and disability in multiple sclerosis (MS) with the hypothalamus-pituitary-adrenal axis is known. This study aimed to investigate the relationship between the morphometric dimensions of the pituitary gland with fatigue and disability.

METHOD

This research, designed as a prospective and case-control study, included 85 MS patients and 45 healthy controls. The disability was evaluated using the expanded disability rating scale (EDSS), while fatigue was determined using the fatigue severity scale (FSS) and the neurological fatigue index (NFI-MS). The morphometric structure of the pituitary gland was measured using a coronal, T2-weighted, turbo-spin-echo sequence of magnetic resonance imaging.

RESULTS

FSS and NFI-MS scores were higher in MS patients than in the control group (p = 0.001). Patients with a progressive and moderate-to-severe disability had a higher FSS score (p = 0.015; p = 0.002, respectively). A positive correlation was determined between disease duration, attack frequency, and EDSS and physical fatigue subscale score (p = 0.001; r = 0.383; 0.373; 0.545, respectively). The height and width of the pituitary gland were higher in MS patients (p = 0.021; p = 0.001, respectively). Pituitary gland height was higher in fatigued patients (p = 0.041). A low-positive correlation was determined between the number of attacks and the height of the pituitary gland (p = 0.027, r = 0.231).

CONCLUSION

The difference in the dimensions of the pituitary gland in MS patients, especially in the fatigued group, supports the relationship of fatigue with morphometric features as well as the hypothalamus-pituitary-adrenal axis.

Effects of multiple sclerosis and medications on menopausal age

Objectives

We aimed to determine whether multiple sclerosis (MS) and methylprednisolone and disease-modifying drugs have an effect on menopausal age.

Methods

A total of 86 patients and 98 healthy subjects were included in this study. The natural menopausal age of the patients and healthy subjects were compared. The cumulative dosages of methylprednisolone, beta interferons (IFNβs), and glatiramer acetate were calculated. The effects of the Expanded Disability Status Scale (EDSS), duration of the disease, and cumulative dosage of medications on menopausal age were evaluated.

Results

The patients’ mean menopausal age was 45.3 ± 4.8 years and healthy subjects’ menopausal age was 46.8 ± 4.3 years, with no significant difference between the two groups. The cumulative dosage of methylprednisolone showed an effect on menopausal age. There was a significant inverse correlation between menopausal age and dosage of IFNβ-1b, while the disease duration and EDSS score showed no correlation with menopausal age.

Conclusions

We conclude that menopausal age is not affected by MS. However, long-term methylprednisolone and IFNβ-1b treatments may change menopausal age in a dose-dependent manner.

The Hypothalamic-Pituitary Axis and Autoantibody Related Disorders

This review summarized different studies reporting the presence of autoantibodies reacting against cells of the pituitary (APAs) and/or hypothalamus (AHAs). Both APAs and AHAs have been revealed through immunofluorescence using different kinds of substrates. Autoantibodies against gonadotropic cells were mainly found in patients affected by cryptorchidism and hypogonadotropic hypogonadism while those against prolactin cells were found in different kinds of patients, the majority without pituitary abnormalities. APAs to growth hormone (GH) cells have been associated with GH deficiency while those against the adrenocorticotropic cells have distinguished central Cushing's disease patients at risk of incomplete cure after surgical adenoma removal. AHAs to vasopressin cells have identified patients at risk of developing diabetes insipidus. APAs have been also found together with AHAs in patients affected by idiopathic hypopituitarism, but both were also present in different kinds of patients without abnormalities of the hypothalamic-pituitary axis. Despite some data being promising, the clinical use of pituitary and hypothalamus autoantibodies is still limited by the low diagnostic sensitivity, irreproducibility of the results, and the absence of autoantigen/s able to discriminate the autoimmune reaction involving the pituitary or the hypothalamus from the other autoimmune states.

Hypothalamic-Pituitary Autoimmunity and Traumatic Brain Injury

Background: Traumatic brain injury (TBI) is a leading cause of secondary hypopituitarism in children and adults, and is responsible for impaired quality of life, disabilities and compromised development. Alterations of pituitary function can occur at any time after the traumatic event, presenting in various ways and evolving during time, so they require appropriate screening for early detection and treatment. Although the exact pathophysiology is unknown, several mechanisms have been hypothesized, including hypothalamic-pituitary autoimmunity (HP-A). The aim of this study was to systematically review literature on the association between HP-A and TBI-induced hypopituitarism. Major pitfalls related to the HP-A investigation were also discussed. Methods: The PubMed database was searched with a string developed for this purpose, without temporal or language limits, for original articles assessing the association of HP-A and TBI-induced hypopituitarism. Results: Three articles from the same group met the inclusion criteria. Anti-pituitary and anti-hypothalamic antibodies were detected using indirect immunofluorescence in a significant number of patients with acute and chronic TBI. Elevated antibody titer was associated with an increased risk of persistent hypopituitarism, especially somatotroph and gonadotroph deficiency, while no correlations were found with clinical parameters. Conclusion: HPA seems to contribute to TBI-induced pituitary damage, although major methodological issues need to be overcome and larger studies are warranted to confirm these preliminary data.

Detection of anti-pituitary autoantibodies by immunoblotting

A new approach to the detection of anti-pituitary autoantibodies by immunoblotting is presented. This method distinguishes pituitary membrane fraction from cytosolic fraction autoantigens and characterizes them by their molecular weight. A 45 kDa pituitary specific membrane protein was identified as an autoantigen in one of 19 patients with idiopathic growth hormone deficiency and the empty sella syndrome. A 43 kDa membrane protein in pituitary and brain was identified as an autoantigen in one other patient with idiopathic growth hormone deficiency and in one of 14 patients with secondary growth hormone deficiency. These autoantibodies were not seen in any of 27 control subjects. Anti-pituitary autoantibodies can be demonstrated by immunoblotting at titres of up to 1/1000. We conclude that immunoblotting is a useful method for the detection of anti-pituitary autoantibodies.

Multiple sclerosis and other immunologic diseases

A characteristic feature of immunologic diseases is their association with each other. For multiple sclerosis (MS), several retrospective studies reported increased as well as expected coincidence rates with other immunologic diseases. We conducted a prospective case-control study of MS patients and healthy volunteers and found 13/101 MS patients and 2/97 controls with such diseases (P = 0.009, chi-square test), as well as 47/88 MS patients versus 31/95 controls with a variety of circulating autoantibodies (P = 0.004, chi-square test). These results speak for an increased coincidence of MS with other immunologic diseases and support the idea that MS is also an immunologic disease.

Serum sex hormone and gonadotropin concentrations in premenopausal women with multiple sclerosis

Dysfunctions within the hypothalamic-pituitary-gonadal axis occur frequently among women with multiple sclerosis (MS) and may induce menstrual disturbances and subsequent infertility. We have measured serum concentrations of prolactin. gonadotropins and sex hormone binding globulin (SHBG) as well as free and bound oestrogen and androgen levels in 14 women of fertile age with MS. These women all displayed regular cycles without having experienced fertility problems. As controls 14 normal women with regular periods and ideal body weight of 91% (range 80-101) were included. Serum from both groups was sampled during the early follicular phase. The MS-patients had significantly (P less than 0.05) higher concentrations of prolactin, LH, FSH, total and free testosterone (P less than 0.01) and a significantly lower serum concentration of oestrone sulphate (P less than 0.01). The abnormal hormone concentrations were not related to clinical status of the disease. We propose that the increased androgen levels are of ovarian origin as adrenal androgens were normal. The reason for the slight increase of prolactin and the marked increase of gonadotropins in women with MS is speculative. As oestradiol levels, however, were within normal range, we assume that a peripheral resistance to gonadotropins combined with an abnormal central regulation causes the increased pituitary secretion.

Parkinson's disease and autoimmunity

Sera from 22 patients with Parkinson's disease were tested for autoantibodies in 11 different assays, including a test for autoantibodies directed against determinants in the pituitary gland. All patients were tested twice with a 12-month interval between tests. No pituitary autoantibodies were detected. The other autoantibodies investigated were found in low frequencies and in low titers. Our data supports the view that the pathogenesis of Parkinson's disease is not autoimmune.

Pituitary-cell autoantibody diversity in sera from patients with untreated Graves' disease

Sera from 22 untreated patients with recently diagnosed Graves' disease (GD) were screened in an immunocytochemical tissue assay for presumptive pituitary IgG autoantibodies, as defined by the presence of immunoreaction with rat and swine pituitary cell types. Forty four patients with Hashimoto's thyroiditis (HT) and 97 healthy subjects were also studied. Anti-pituitary antibodies were found in 14 of the 22 GD sera (64%). Of these, 6 sera reacted with cytoplasmic components of growth hormone (GH) cells, 3 with prolactin (PRL) cells, and 5 with both GH and PRL cells. Yet, none of the immunoreactive sera reacted with human GH, bovine PRL or TSH in dot-blot assays and absorption studies. Anti-pituitary antibodies also occurred in 4 of the 44 HT patients (9.1%) and in 9 of the 97 healthy subjects (9.2%). The frequency of sera revealing anti-pituitary antibodies was significantly higher in patients with GD compared to the groups of HT patients (P less than 0.00005), and healthy subjects (P less than 0.00005). Healthy subjects and patients with HT had a similar frequency of anti-pituitary antibodies (P = 1.0000). These data demonstrate that in thyroid autoimmune conditions antibodies reactive with cytoplasmic components of pituitary GH/PRL cells, may be present in sera from patients with GD. The pathological importance of this observation is at present unknown.

Multiple sclerosis and the evolution of growth hormone mechanisms in man

This paper develops the hypothesis that a growth hormone-like substance and/or its receptor is the initial target of auto-antibodies in multiple sclerosis (MS). Regulatory mechanisms for hormone secretion may also be involved in the pathogenesis of MS. Demyelination may be subsequent (1) to an initial lesion to the anterior pituitary.

Screening of multiple sclerosis cerebrospinal fluid for autoantibodies

An enzyme-linked immunoadsorbent assay, using nitrocellulose discs as solid phase and small sample volumes (50 microliter), was developed for the measurement of antibodies. This was used to screen CSF samples for autoantibodies against tissue components. Extracts from a selection of tissues from both "normal" and MS patients and from 3 glial cell lines were made in phosphate-buffered saline; in the case of neural and lymphoid samples the remaining particulate materials were subsequently solubilised with octylglucoside. The saline-soluble components were screened against CSF samples from MS patients (18), patients with other neurological disorders (10), and matched orthopaedic patients but no differences were found among the 3 groups. However, when the detergent-soluble components were screened a significant (at the P less than or equal to 0.01 level) elevation of reactivity towards brain was found in 6/16 MS patients and 2/12 patients with other neurological diseases when compared to their controls.

Autoantibodies to pituitary corticotropin-producing cells: possible marker for unfavourable outcome after pituitary microsurgery for Cushing's disease

Circulating autoantibodies to human fetal pituitary cells were detected in 13 out of 51 patients who underwent transsphenoidal microsurgery for Cushing's disease. The absence of Fc receptors on human fetal pituitary corticotropin-producing cells allowed the detection of antibodies to these cells. In all the 13 patients, the antibodies were present before surgery, and 10 of them showed clinical and/or biochemical signs of incomplete cure of Cushing's disease after surgery. Only 3 out of 27 patients with a favourable outcome were antibody-positive. In all the antibody-positive patients, the antibodies were directed to corticotropin-producing cells and in 8 patients also to luteinising hormone or human growth hormone producing cells. A non-antigen-specific adherence of antibodies to Fc-receptors on corticotropin-cells was excluded by unchanged binding after preincubation of sections with purified rabbit Fc or Fc aggregates. The presence of pituitary corticotropin-cell antibodies in patients with Cushing's disease is associated with an unsuccessful outcome after transsphenoidal selective adenectomy.

Localisation of oxytocin, vasopressin and parts of precursors in the human neonatal adrenal

Being a possible alternative source for the production of vasopressin (AVP) and oxytocin (OXT), a study was undertaken of the fetal adrenal. The concentrations of these peptides within the fetal adrenal turned out to be low, viz., approx. 1 pg/mg in the rat and within the pg/g range in the human. Immunocytochemistry was performed either on conventional autopsy material kept till 12 years in paraffin blocks, or on more recently obtained formalin or glutaraldehyde-paraformaldehyde fixed material. In both types of material staining was good. In order to localize AVP cells, anti-AVP, an antibody against its associated neurophysin (anti-NSN) or an antibody raised against the c-terminal glycopeptide part of the AVP precursor (anti-GP) was used. OXT cells were localized by means of anti-OXT or an auto-antibody of a multiple sclerosis patient (auto-MS) probably recognizing OXT-neurophysin. The antibodies were characterized on human and rat brain material. In the external zone of the definitive cortex, apart from parenchyma cells, anti-AVP, anti-NSN and anti-GP stained fibre-like structures running in the connective tissue septa and around parenchyma cells and the cytoplasma of these cells. Anti-OXT and auto-MS stained droplets in the cytoplasm of the fetal zone cells. Similar distinct staining patterns for AVP and OXT cells were obtained in human anencephalics. These observations show that the peptides are not derived from the fetal brain, but are rather produced in the fetal adrenal cortex.(ABSTRACT TRUNCATED AT 250 WORDS)

Demonstration of autoantibodies against ACTH in serum from a patient with cancer of unknown origin

We report the presence of autoantibodies against ACTH in plasma from a 46 year old man with poorly differentiated adenocarcinoma of unknown origin. There was no evidence of Cushing's syndrome. By radioimmunoassay and immunocytochemical technique the antibodies were found to possess specificity against the 13-24 aminoacid sequence of ACTH. This sequence includes the biologically active site. On the basis of our findings it is discussed whether the presence of the autoantibodies could reflect a fundamental immunological disturbance primarily or secondarily related to cancer.