Diss. (sammanfattning) Uppsala : Univ., 2001. / Härtill 4 uppsatser.

This thesis presents genetic studies aiming at enlarging our knowledge regarding the genetic factors underlying two immune-mediated diseases, hypothyroidism and autoimmune Addison’s disease (AAD), in dogs and humans, respectively. Genetic and environmental factors are indicated to contribute to canine hypothyroidism, which can be considered a model for human Hashimoto’s thyroiditis (HT). In Paper I we performed the first genome-wide association (GWA) study of this disease in three high-risk dog breeds (Gordon Setter, Hovawart and Rhodesian Ridgeback). Using an integrated GWA and meta-analysis strategy, we identified a novel hypothyroidism risk haplotype located on chromosome 12 being shared by the three breeds. The identified haplotype, harboring three genes previously not associated with hypothyroidism, is independent of the dog leukocyte antigen region and significantly enriched across the affected dogs. In Paper II we performed a GWA study in another high-risk breed (Giant Schnauzer) and detected an associated locus located on chromosome 11 and conferring protection to hypothyroidism. After whole genome resequencing of a subset of samples with key haplotypes, we fine mapped the region of association that was subsequently screened for the presence of structural variants. We detected a putative copy number variant overlapping with the upstream region of the IFNA7 gene, which is located in a region of high genomic complexity. Remarkably, perturbed activities of type I Interferons have been extensively associated with HT and general autoimmunity. In Paper III we performed the first large-scale genetic study of human AAD, a rare autoimmune disorder characterized by dysfunction and ultimately destruction of the adrenal cortex. We resequenced 1853 immune-related genes comprising of their coding sequences, untranslated regions, as well as conserved intronic and intergenic regions in extensively characterized AAD patients and control samples, all collected in Sweden. We identified BACH2 gene as a novel risk locus associated with AAD, and we showed its independent association with isolated AAD. In addition, we confirmed the previously established AAD association with the human leukocyte antigen complex. The results of these studies will hopefully help increasing the understanding of such diseases in dogs and humans, eventually promoting their well-being.

Autoimmune diseases occur when the immune system attacks and destroys healthy body tissue. Autoimmunity is known to cause a wide range of disorders, and is suspected to be responsible for many more. Most autoimmune disorders are chronic and cause severe morbidity for the patients, and are also costly for society. A majority of these disorders are today considered as complex diseases with incompletely known etiology. Hence, model systems for studying the pathogenesis of autoimmunity are important to unravel its causes. Autoimmune Polyendocrine Syndrome Type 1 (APS-1), (OMIM 240300), is a rare autoimmune disorder. Patients with APS-1 progressively develop multiple organ-specific autoimmune lesions involving both endocrine and non endocrine tissues. Typical autoimmune disease components in APS-1 are hypoparathyroidism, Addison’s disease, vitiligo, alopecia and type 1 diabetes. The gene preventing APS-1 has been identified and designated Autoimmune Regulator (AIRE). It has been shown that mutations of AIRE cause loss of tolerance to self-structures, resulting in organ-specific autoimmunity. Although APS-1 is a rare syndrome occurring mainly in genetically isolated populations, the disease components of APS-1 are, in isolated forms, not unusual in the general population and affect many patients. Hence, APS-1 is an attractive model disease for studies of molecular mechanisms underlying organ-specific autoimmunity. This thesis concerns investigations in which two novel autoantigens are identified in APS-1 and used in serological diagnosis of the disease. NALP5, is identified as a parathyroid autoantigen - an important finding since autoimmune hypoparathyroidism is one of the cardinal symptoms of APS-1. Additionally, KCNRG is identified as a bronchial autoantigen in APS-1 patients with respiratory symptoms. Finally, studies that compare the immune response in APS-1 patients and the mouse model for APS-1 are presented.

Die Psychoneuroimmunologie beschäftigt sich unter anderem mit der Frage, ob und unter welchen Bedingungen psychosozialer Stress krank macht. Humanstudien, die dieser Frage nachgehen, können dabei meist nur korrelative Zusammenhänge aufdecken. Um trotzdem Aussagen zu Mechanismen, Ursache-Wirkungsbeziehungen und klinische Relevanz treffen zu können, muss z.B. auf Befunde aus der Tierforschung oder aus in vitro-Studien zurückgegriffen werden. Ziel der vorliegenden Arbeit war es, eine Methode zu finden, welche eine breitere Interpretationsgrundlage für korrelative Befunde aus Humanstudien liefert. Als besonders viel versprechend kann die Untersuchung von Patienten mit Morbus Addison angesehen werden. Patienten mit dieser Erkrankung können aufgrund zerstörter Nebennierenrinden kein Cortisol produzieren. Dieses Fehlen von Cortisol wird medikamentös ausgeglichen. Da bislang keine experimentellen Daten zu den aus der Substitutionstherapie resultierenden freien Cortisolkonzentrationen sowie den endokrinologischen Reaktionen auf Stress vorliegen, wurden in einem ersten Schritt diese beiden Fragestellungen bearbeitet. Anschließend wurde die Methode auf immunologische Fragestellungen angewandt. Die Ergebnisse der durchgeführten Studien zeigen zum einen, dass die medikamentöse Morbus Addison-Therapie in der momentanen Form nicht geeignet ist, den bei Gesunden zu beobachtenden zirkadianen Cortisolrhythmus optimal nachzustellen. Des weiteren bestätigte sich, dass psychosozialer Stress bei Patienten mit Morbus Addison lediglich eine Noradrenalinantwort auslöst, stress-induzierte Anstiege in Cortisol und Adrenalin jedoch ausbleiben. Eine Injektion von 0.03mg/kg Hydrocortison nach einem akuten Stresstest zeigte sich als geeignet, normale stressinduzierte Cortisolanstiege und Maximalwerte nachzustellen. In den untersuchten Immunparametern unterschieden sich gesunde Probanden und Patienten mit Morbus Addison vor Stressinduktion nicht. Stress-bedingte Veränderungen in peripheren Lymphozytenzahlen lassen sich dahingehend interpretieren, dass bei Patienten zwar akut eine Einwanderung von Lymphozyten aus dem Gewebe in das Blut stattfindet, aber Cortisol mitverantwortlich ist für die anschließende Redistribution. Bleibt eine Cortisolstressantwort aus, deutet dieser Befund auf ein erhöhtes Infektionsrisiko hin. Die Verläufe zur stimulierten Produktion des Entzündungsmediators Interleukin-6 stehen im Einklang mit der Hypothese, dass stress-induzierte Cortisolkonzentrationen vor einer überschießenden Entzündungsreaktion schützen. Des weiteren lässt sich bei gesunden Probanden das Absinken der NF-?B-Aktivität nach Stress durch Cortisolwerte direkt nach Stress, bei Morbus Addison-Patienten hingegen durch Veränderungen im Noradrenalin vorhersagen. Das vorliegende Dissertationsprojekt konnte zeigen, dass die Untersuchung von Patienten mit Morbus Addison ein Erfolg versprechender Ansatz ist, um die Gültigkeit von psychoneuroimmunologischen in vitro- und Tierbefunden im intakten menschlichen Organismus zu überprüfen. Die vorliegenden Daten deuten zudem auf eine erstaunliche Anpassungsfähigkeit des Immunsystems hin, was die Notwendigkeit deutlich macht, komplexe psychoneuroimmunologische Prozesse auch im Humanbereich unter Anwendung der Kriterien Hormonsubtraktion und -substitution zu untersuchen. Die Untersuchung von Morbus Addison-Patienten wird in zukünftigen Studien sicherlich entscheidende Hinweise zur klinischen Relevanz einer normalen endokrinen Stressantwort liefern können. / The field of psychoneuroimmunology is among other things dedicated to the question, whether and on what terms psychosocial stress results in disease. Human studies investigating this question often only reveal associations. Consequences regarding mechanisms, causes, and clinical relevance, are thus usually deduced from animal or in vitro studies. The aim of the present thesis was to find an approach, which provides a broader basis for interpretations of correlative findings from human studies. The investigation of patients with Addison´s disease was regarded as the most promising approach. Due to destroyed adrenal glands, these patients are not able to produce cortisol, which therefore has to be substituted. Since no experimental data regarding free cortisol levels resulting from substitution therapy as well as endocrine stress responses are available, in a first step these two question formulations were investigated. Subsequently, this approach was used to investigate two immunological question formulations. The present studies found patients with Addison´s disease to be over-treated. Psychosocial stress resulted in noradrenaline but not in cortisol or adrenaline responses. An injection of 0.03mg/kg hydrocortisone after stress was suitable to induce increases in cortisol levels and cortisol maximums comparable to healthy subjects. Healthy subjects and patients with Addison´s disease did not differ in any baseline immune measures. Stress-induced changes in lymphocyte numbers suggest cortisol being necessary for lymphocyte redistribution subsequent to stress-induced migration into peripheral blood. Without stress-induced cortisol increases, patients are at higher risk for infectious diseases. The trajectories of stimulated interleukin-6 production support the hypothesis of stress-induced cortisol levels protecting the organism against an over-reacting inflammatory immune reaction. Furthermore, in healthy subjects post-stress cortisol levels predicted stress-induced decreases in NF-´B activity, whereas in patients with Addison´s disease noradrenaline predicted such changes. The results of the present thesis supports the assumption of Addison´s disease being a promising approach to test the validity of psychoneuroimmunological in vitro and animal data in human whole organism. Additionally, the present data emphasize the astonishing adaptability of the immune system. This further emphasizes the necessity to investigate psychoneuroimmunological processes utilizing the criteria of hormone subtraction and hormone substitution also in human research. In future studies investigation of patients with Addison´s diseases will certainly provide crucial evidence regarding the clinical relevance of a normal endocrine stress response.

Die Psychoneuroimmunologie beschäftigt sich unter anderem mit der Frage, ob und unter welchen Bedingungen psychosozialer Stress krank macht. Humanstudien, die dieser Frage nachgehen, können dabei meist nur korrelative Zusammenhänge aufdecken. Um trotzdem Aussagen zu Mechanismen, Ursache-Wirkungsbeziehungen und klinische Relevanz treffen zu können, muss z.B. auf Befunde aus der Tierforschung oder aus in vitro-Studien zurückgegriffen werden. Ziel der vorliegenden Arbeit war es, eine Methode zu finden, welche eine breitere Interpretationsgrundlage für korrelative Befunde aus Humanstudien liefert. Als besonders viel versprechend kann die Untersuchung von Patienten mit Morbus Addison angesehen werden. Patienten mit dieser Erkrankung können aufgrund zerstörter Nebennierenrinden kein Cortisol produzieren. Dieses Fehlen von Cortisol wird medikamentös ausgeglichen. Da bislang keine experimentellen Daten zu den aus der Substitutionstherapie resultierenden freien Cortisolkonzentrationen sowie den endokrinologischen Reaktionen auf Stress vorliegen, wurden in einem ersten Schritt diese beiden Fragestellungen bearbeitet. Anschließend wurde die Methode auf immunologische Fragestellungen angewandt. Die Ergebnisse der durchgeführten Studien zeigen zum einen, dass die medikamentöse Morbus Addison-Therapie in der momentanen Form nicht geeignet ist, den bei Gesunden zu beobachtenden zirkadianen Cortisolrhythmus optimal nachzustellen. Des weiteren bestätigte sich, dass psychosozialer Stress bei Patienten mit Morbus Addison lediglich eine Noradrenalinantwort auslöst, stress-induzierte Anstiege in Cortisol und Adrenalin jedoch ausbleiben. Eine Injektion von 0.03mg/kg Hydrocortison nach einem akuten Stresstest zeigte sich als geeignet, normale stressinduzierte Cortisolanstiege und Maximalwerte nachzustellen. In den untersuchten Immunparametern unterschieden sich gesunde Probanden und Patienten mit Morbus Addison vor Stressinduktion nicht. Stress-bedingte Veränderungen in peripheren Lymphozytenzahlen lassen sich dahingehend interpretieren, dass bei Patienten zwar akut eine Einwanderung von Lymphozyten aus dem Gewebe in das Blut stattfindet, aber Cortisol mitverantwortlich ist für die anschließende Redistribution. Bleibt eine Cortisolstressantwort aus, deutet dieser Befund auf ein erhöhtes Infektionsrisiko hin. Die Verläufe zur stimulierten Produktion des Entzündungsmediators Interleukin-6 stehen im Einklang mit der Hypothese, dass stress-induzierte Cortisolkonzentrationen vor einer überschießenden Entzündungsreaktion schützen. Des weiteren lässt sich bei gesunden Probanden das Absinken der NF-?B-Aktivität nach Stress durch Cortisolwerte direkt nach Stress, bei Morbus Addison-Patienten hingegen durch Veränderungen im Noradrenalin vorhersagen. Das vorliegende Dissertationsprojekt konnte zeigen, dass die Untersuchung von Patienten mit Morbus Addison ein Erfolg versprechender Ansatz ist, um die Gültigkeit von psychoneuroimmunologischen in vitro- und Tierbefunden im intakten menschlichen Organismus zu überprüfen. Die vorliegenden Daten deuten zudem auf eine erstaunliche Anpassungsfähigkeit des Immunsystems hin, was die Notwendigkeit deutlich macht, komplexe psychoneuroimmunologische Prozesse auch im Humanbereich unter Anwendung der Kriterien Hormonsubtraktion und -substitution zu untersuchen. Die Untersuchung von Morbus Addison-Patienten wird in zukünftigen Studien sicherlich entscheidende Hinweise zur klinischen Relevanz einer normalen endokrinen Stressantwort liefern können. / The field of psychoneuroimmunology is among other things dedicated to the question, whether and on what terms psychosocial stress results in disease. Human studies investigating this question often only reveal associations. Consequences regarding mechanisms, causes, and clinical relevance, are thus usually deduced from animal or in vitro studies. The aim of the present thesis was to find an approach, which provides a broader basis for interpretations of correlative findings from human studies. The investigation of patients with Addison´s disease was regarded as the most promising approach. Due to destroyed adrenal glands, these patients are not able to produce cortisol, which therefore has to be substituted. Since no experimental data regarding free cortisol levels resulting from substitution therapy as well as endocrine stress responses are available, in a first step these two question formulations were investigated. Subsequently, this approach was used to investigate two immunological question formulations. The present studies found patients with Addison´s disease to be over-treated. Psychosocial stress resulted in noradrenaline but not in cortisol or adrenaline responses. An injection of 0.03mg/kg hydrocortisone after stress was suitable to induce increases in cortisol levels and cortisol maximums comparable to healthy subjects. Healthy subjects and patients with Addison´s disease did not differ in any baseline immune measures. Stress-induced changes in lymphocyte numbers suggest cortisol being necessary for lymphocyte redistribution subsequent to stress-induced migration into peripheral blood. Without stress-induced cortisol increases, patients are at higher risk for infectious diseases. The trajectories of stimulated interleukin-6 production support the hypothesis of stress-induced cortisol levels protecting the organism against an over-reacting inflammatory immune reaction. Furthermore, in healthy subjects post-stress cortisol levels predicted stress-induced decreases in NF-´B activity, whereas in patients with Addison´s disease noradrenaline predicted such changes. The results of the present thesis supports the assumption of Addison´s disease being a promising approach to test the validity of psychoneuroimmunological in vitro and animal data in human whole organism. Additionally, the present data emphasize the astonishing adaptability of the immune system. This further emphasizes the necessity to investigate psychoneuroimmunological processes utilizing the criteria of hormone subtraction and hormone substitution also in human research. In future studies investigation of patients with Addison´s diseases will certainly provide crucial evidence regarding the clinical relevance of a normal endocrine stress response.

<p>Organ-specific autoimmunity constitutes a large health problem, where both the clinical management and our understanding of the pathogenetic mechanisms need to improve. Women with Addison's disease have abnormally low levels of dehydroepiandrosterone (DHEA), its sulphate ester (DHEA-S) and androgens relative to age, and many patients complain of physical and mental fatigue and low stress tolerance. To define a suitable dose, the effect of oral DHEA replacement was evaluated in women with Addison's disease. </p><p> DHEA was administered for three months to nine women with Addison's disease in either of two doses, 50 mg (n=5) or 200 mg (n=4). A dose of 50 mg restored the DHEA(S) and androgen levels to normal without altering the insulin sensitivity, body composition or serum lipid profile.</p><p> Autoimmune polyendocrine syndrome type I (APS I) is a rare but useful model disorder of autoimmunity, characterised by multiple organ-specific autoimmune manifestations and high-titre autoantibodies and with adrenocortical insufficiency, Addison's disease, as one of its cardinal manifestations. Approximately 10-20% of APS I patients suffer from autoimmune hepatitis, which carries a high mortality, if untreated. The presence of putative antigenic targets in the liver was investigated.</p><p> Cytochrome P4501A2 (CYP1A2) and aromatic L-amino acid decarboxylase (AADC) were identified as hepatic autoantigens with the use of APS I sera for immunofluorescent staining of normal human liver, Western blot of microsomal and cytosol fractions of human liver homogenate, and immunoprecipitation of <i>in vitro</i> transcribed and translated radioactively labelled proteins. The presence of CYP1A2- and AADC-antibodies was significantly correlated to AIH, and CYP1A2 antibodies inhibited enzyme activity <i>in vitro</i>.</p><p><i> In conclusion</i>, a daily replacement dose of 50 mg of DHEA sufficiently restores levels of DHEA, DHEA(S) and androgens in women with Addison's disease, without severe side-effects. We have further identified CYP1A2 and AADC as hepatic autoantigens associated with autoimmune hepatitis in APS I.</p>

Organ-specific autoimmunity constitutes a large health problem, where both the clinical management and our understanding of the pathogenetic mechanisms need to improve. Women with Addison's disease have abnormally low levels of dehydroepiandrosterone (DHEA), its sulphate ester (DHEA-S) and androgens relative to age, and many patients complain of physical and mental fatigue and low stress tolerance. To define a suitable dose, the effect of oral DHEA replacement was evaluated in women with Addison's disease. DHEA was administered for three months to nine women with Addison's disease in either of two doses, 50 mg (n=5) or 200 mg (n=4). A dose of 50 mg restored the DHEA(S) and androgen levels to normal without altering the insulin sensitivity, body composition or serum lipid profile. Autoimmune polyendocrine syndrome type I (APS I) is a rare but useful model disorder of autoimmunity, characterised by multiple organ-specific autoimmune manifestations and high-titre autoantibodies and with adrenocortical insufficiency, Addison's disease, as one of its cardinal manifestations. Approximately 10-20% of APS I patients suffer from autoimmune hepatitis, which carries a high mortality, if untreated. The presence of putative antigenic targets in the liver was investigated. Cytochrome P4501A2 (CYP1A2) and aromatic L-amino acid decarboxylase (AADC) were identified as hepatic autoantigens with the use of APS I sera for immunofluorescent staining of normal human liver, Western blot of microsomal and cytosol fractions of human liver homogenate, and immunoprecipitation of in vitro transcribed and translated radioactively labelled proteins. The presence of CYP1A2- and AADC-antibodies was significantly correlated to AIH, and CYP1A2 antibodies inhibited enzyme activity in vitro. In conclusion, a daily replacement dose of 50 mg of DHEA sufficiently restores levels of DHEA, DHEA(S) and androgens in women with Addison's disease, without severe side-effects. We have further identified CYP1A2 and AADC as hepatic autoantigens associated with autoimmune hepatitis in APS I.

Diss. (sammanfattning) Stockholm : Karol inst., 2003. / Härtill 5 uppsatser.