Expression of the class I interferon-related MxA protein in temporal arteries in polymyalgia rheumatica and temporal arteritis.

OBJECTIVE: The aim of this study was to assess the expression of the interferon type I (IFN-I)-associated MxA protein in polymyalgia rheumatica (PMR) and temporal arteritis (TA). METHODS: Non-inflamed temporal artery biopsies from 11 PMR patients were compared with biopsies from 13 patients given other diagnoses. Coded sections were screened immunocytochemically for MxA protein, CD83, CD68, CD3, and S100 protein. Inflamed temporal artery biopsies from four patients with TA were also investigated. RESULTS: Focal MxA expression was seen in non-inflamed arteries, more frequently in PMR than in controls (p = 0.0124). MxA expression was also more common in adventitial dendritic cells (DCs) in PMR (p = 0.0124). Activated adventitial DCs were detected in PMR. Focal MxA expression in the inflamed biopsies from the patients with TA was not related spatially to the inflammation. CONCLUSIONS: The expression of MxA protein in arteries from patients with PMR and TA shows that non-inflamed and inflamed vessel walls are influenced by IFN-I. Further studies are required to elucidate whether IFN-I plays a role in the initiation of PMR and/or TA, serving as a link between the innate and the adaptive immune responses, as in some other autoimmune disorders.

Comparison of soluble ICAM-1, VCAM-1 and E-selectin levels in patients with episodic cluster headache and giant cell arteritis.

The pathophysiology of cluster headache (CH) is supposed to involve the lower posterior part of the hypothalamus, the trigeminal nerve, autonomic nerves and vessels in the orbital/retro-orbital region. The exact connection of this hypothalamic-trigemino-autonomic-vascular axis is not fully understood. The presence of inflammation in the perivascular tissue of the retro-orbital region has been presented as a possible mechanism behind the pain and the sympatheticoplegia sometimes observed during headache attacks. In a previous study we found neither increased levels of erythrocyte sedimentation rate, C-reactive protein or acute-phase reactants nor clinical signs of a generalized inflammatory disorder. However, these tests may not be sensitive enough to detect a focal inflammatory process in the retro-orbital region. In the present study, we analysed serum levels of three soluble adhesion molecules; soluble intercellular adhesion molecule-1 (sICAM-1), soluble vascular cell adhesion molecule-1 (sVCAM-1) and soluble E-selectin (sE-selectin) in patients with episodic CH and in patients with biopsy-positive giant cell arteritis (GCA), a known vasculitic disorder of large and medium-sized arteries. A control group of healthy volunteers was also included. Within the CH group, sICAM-1, sVCAM-1 and sE-selectin showed an increasing trend in remission compared with the active CH period, but the difference was statistically significant for sE-selectin only. The mean sICAM-1 value was higher in patients with active GCA than in CH patients during the active cluster period. Compared with the healthy control group, the mean levels of soluble adhesion molecules in CH patients also tended to be higher, but statistically significantly so only for sVCAM-1. We hypothesize that CH is not a vasculitic disorder of the medium-sized arteries, but CH patients may have an immune response that reacts differently from that of healthy volunteers.

An uneven expression of T cell receptor V genes in the arterial wall and peripheral blood in giant cell arteritis.

The aim of the study was to investigate T cell receptor (TCR) usage at the time of diagnosis of giant cell arteritis (GCA) and to estimate the degree of clonality of T-cells infiltrating the lesion. Seven patients with biopsy-proven giant cell arteritis were included in the study. Immunocytochemistry in biopsies from the temporal arteries and flow cytometric analysis of peripheral blood lymphocytes (PBL) was performed using monoclonal antibodies specific for CD3, CD4 and CD8 and 13 TCR Valpha and Vbeta gene segment products. The CDR3 fragment length polymorphism was assessed by gel electrophoresis of PCR-amplified TCR segments. The T lymphocytes were found to be concentrated to the adventitia rather than the media or intima. Six of the seven patients with GCA had expansions of T lymphocytes, expressing selected TCR V genes in the arterial wall. None of these expansions was found in PBL. The infiltrating T-cells were poly- or oligoclonal. In conclusion, the dominating part of the inflammatory infiltrate in GCA emanates from the adventitial microvessels. There is an uneven expression of TCR V genes by T lymphocytes in the inflammatory infiltrates as compared to peripheral blood T lymphocytes at the time of diagnosis, consistent with an antigen-driven immunological reaction in the arterial wall.

A Western blot and molecular genetic investigation of the estrogen receptor beta in giant cell arteritis.

OBJECTIVE: The epidemiology of giant cell arteritis (GCA) may indicate a pathogenetic relationship between GCA and female sex hormone metabolism; GCA is two to four times more common in women compared with men. Our previous analyses gave no support for the hypothesis that the pathogenesis of GCA should be related to somatic mutations in the estrogen receptor alpha (ERalpha) gene. The object of the present study was to investigate the size of the estrogen receptor beta (ERBeta), and the size and nucleotide sequence of the ERBeta gene in temporal arteries in GCA. METHODS: The ERBeta protein was analyzed by Western blot technique and the ERBeta gene by RT-PCR and direct sequencing of the PCR product. RESULTS: Western blot analysis revealed an ERBeta of normal size. There were no aberrations in size or nucleotide sequence in the ERBeta gene in the GCA patients. CONCLUSION: The present observations gave no support for the hypothesis that somatic mutations in the ERBeta gene should be involved in the pathogenesis of GCA.

Cell-type-specific expression of p53 and p21 in giant cell arteritis.

The aim of the present study was to investigate the expression of TP53 (p53) and CDKN1A (CIP1; p21) in the arterial wall in giant cell arteritis (GCA). Cross-sections from 18 temporal artery biopsies displaying GCA and 8 control arteries were double-stained with monoclonal antibody directed at p53 or p21 on the one hand and alpha-smooth muscle actin, CD68 (macrophage) or CD3 (T-cell) on the other. Nuclear p53 was expressed in CD68-positive cells and smooth muscle cells in 16 of the 18 inflamed arteries. P21-positive nuclei were found in CD68-positive cells in 14 biopsies and in smooth muscle cells in all the specimens. All p53-positive giant cells also contained p21-positive nuclei. In the giant cells, immunopositive nuclei were mixed with negative ones. CD3-positive T-cells did not express p53 or p21. Only one p53-positive smooth muscle cell nucleus was found in the non-GCA controls and, compared with GCA, p21 expression was noted in few smooth muscle nuclei. The presence of p53 and p21 in the same types of cell in GCA indicates that the former protein is functional; p21 expression is induced by wild-type, functional p53 but not by its mutant form. The current observations suggest cellular stress in GCA, the nature of which requires further investigation.

Giant cell arteritis. Epidemiology, etiology and pathogenesis.

Giant cell arteritis (GCA) is a chronic inflammatory disorder targeting large and medium-sized arteries, which predominantly affects postmenopausal women. Its high incidence in populations with Scandinavian lineage, some familial accumulation, and the association with the HLA-DR4 haplotype indicate a genetic predisposition. Epidemiological observations, as well as the symptomatology, may indicate an infectious origin, but so far GCA has not been shown to be a truly infectious form of vasculitis. Immunological research indicates an antigen-driven disease with local T-cell and macrophage activation in the vessel wall. Morphologically, the inflammatory process appears to be initiated by a foreign-body giant-cell attack on calcified internal elastic membrane in arteries and on calcified atrophic parts of the aortic media. The ensuing diffuse chronic inflammation leads to vessel dilatation and extensive intimal thickening. The latter, which relates to the production of promoting factors by the inflammatory cells, causes arterial stenosis and ischemic complications. The possible role of female sex hormones in GCA requires further investigation. Mononuclear and giant cells in GCA display the cytoplasmic accumulation of estrogen receptor (ER) alpha. Cytoplasmic ER-alpha is also seen in media smooth-muscle cells in GCA and in non-GCA controls, but nucleotide sequence analysis of the ER-alpha gene revealed no differences between GCA patients and controls. In the future, comprehensive morphological, cell biological and immunological research will be required for a better understanding of the complex etiology and pathogenesis of GCA.

Atrophy of the aortic media in giant cell arteritis.

Aortic tissue from seven patients with giant cell arteritis (GCA) was investigated using light microscopy and immunocytochemistry. Four surgical cases and three autopsy cases were included. All the specimens displayed a severe reduction in the size and number of media smooth muscle cells immunopositive for alpha-smooth muscle actin (alpha-SMA). A subtotal loss of alpha-SMA-positive cells was seen in non-inflamed media tissue, continuing gradually towards multiple calcified acellular lesions totally devoid of alpha-SMA immunoreactivity. There was a slight to moderate granulomatous inflammatory reaction in the tissue surrounding part of the acellular lesions. Foreign body giant cell reaction and elastin degradation were found at the ends of the acellular calcified areas. The present findings indicate that the atrophy and the loss of alpha-SMA-positive cells in the aortic media in GCA is primary, and that the granulomatous reaction is secondary and directed against atrophic calcified media tissue.

Temporal artery morphology and morphometry in giant cell arteritis.

Paraffin sections and more than 7,000 plastic cross-sections of temporal arteries from 27 patients with a clinical diagnosis of polymyalgia rheumatica (PMR), 16 patients with a clinical diagnosis of temporal arteritis (TA) and 18 age- and sex-matched postmortem controls were studied using light microscopy. A new method was developed to permit a morphometric comparison between biopsies and autopsy specimens. Two stages of inflammation were discerned in TA. In atrophic arterial segments there was a focal, foreign-body, giant-cell reaction to the calcified internal elastic membrane (IEM) with a spatially correlated, mononuclear cell infiltration. Isolated giant cells were also found to attack the IEM in these cases. The majority of the biopsies displayed a different picture with a diffuse macrophage attack on media and intima with numerous and apparently macrophage-derived giant cells, which did not attack calcifications. The latter arteries were significantly widened (p less than 0.02), which indicates that this phase is the later one. Non-inflamed segments of PMR vessels displayed a significant, non-reactive media atrophy compared with controls (p less than 0.03) and their IEM calcifications were significantly larger (p less than 0.02). The circumference was smaller in atrophic PMR arteries than in inflamed TA arteries (p less than 0.006), which contradicts post-inflammatory scarring.

Giant cell arteritis.

Whereas giant cell arteritis (GCA) was considered a rare disease 50 years ago, the generalized arteritis is now recognized as an important and significant cause of morbidity in elderly people; its cause and pathogenesis is poorly understood. Glucocorticosteroids are the drug of choice in all clinical types of GCA. In contrast to corticosteroids, nonsteroidal anti-inflammatory drugs have no proven effect on vascular complications to GCA, and cannot be recommended.

Epidemiology of biopsy-positive giant cell arteritis: an overview.

Giant cell arteritis (GCA) is reported world-wide. However, the incidence varies greatly in different geographic regions with the highest incidence rates from Scandinavian countries and North American populations of the same descent. The etiopathogenesis of GCA is incompletely understood. Although data on a positive correlation between the occurrence of infection and the onset of GCA as well as rhythmic fluctuations in disease incidence have been reported, no statistically significant periodicity has so far been found regarding the annual incidence of GCA. Seasonal variations may indicate a role of infection or other environmental factors in the pathogenesis of GCA.

The inflammatory reaction in giant cell arteritis: an immunohistochemical investigation.

OBJECTIVE: To assess the distribution of the inflammatory reaction in giant cell arteritis (GCA). METHODS: Semiquantitative analysis on cryostat sections stained with monoclonal antibodies against inflammatory markers. RESULTS: The inflammatory infiltration was strongest in the adventitia where it showed sharp demarcation along the outer border of the media. The endothelial immunopositivity for HLA-DR was strongest in adventitial microvessels. The immunopositivity for macrophages, B-cells, HLA-DR, ICAM-1 and IL-2 was significantly stronger in the outer than in the inner half of the intima. CONCLUSION: The distribution of immunostainings and the crowding of cells seen at the outer media border indicates that the majority of the inflammatory cells enter the arterial wall from adventitial microvessels, migrate through the media and that the cell migration and the inflammatory activity focuses on the peripheral intima/internal elastic membrane.

The pathogenesis of giant cell arteritis: morphological aspects.

The light-microscopic, electron-microscopic and immunocytochemical characteristics of giant cell arteritis (GCA) have been investigated in a number of studies on temporal arteries. Arterial atrophy and calcification of the internal elastic membrane appear to be prerequisites for the evolution of the inflammatory process. Foreign body giant cells form close to calcifications, apparently without connection with other inflammatory cells and probably by the fusion of modified vascular smooth muscle cells. The foreign body giant cells attack the calcifications. Lymphocytes accumulate around them and may be found in pockets in their cell surface. This focal reaction is found in atrophic, calcified arterial segments in a minority of inflamed temporal artery biopsies. More commonly seen is a diffuse mononuclear attack of the vessel wall in atrophic as well as non-atrophic segments which leads to severe arterial dilatation. Langhans giant cells form by the fusion of macrophages in the diffuse inflammatory infiltrate. The fact that the diffusely inflamed arteries are markedly widened compared to the focally inflamed vessels suggests that the inflammatory process starts as a focal foreign body giant cell reaction directed at calcifications which in turn initiates a more diffuse and widespread inflammation.

Morphological aspects of giant cells in giant cell arteritis: an electron-microscopic and immunocytochemical study.

OBJECTIVES: To compare the morphology of foreign body and Langhans giant cells in the two different inflammatory phases of giant cell arteritis (GCA). METHODS: Electron microscopy was performed on 6 positive temporal arterial biopsies. Light microscopy and immunocytochemistry for macrophage-associated antigen (KP1) and alpha-smooth muscle actin (alpha-SMA) were performed on 16 positive biopsies. RESULTS: A focal granulomatous reaction with foreign body giant cells was found only in association with the internal elastic membrane (IEM) in atrophic arterial segments, which often displayed calcification of the IEM. Diffuse invasion of lymphocytes and monocytes/macrophages affected non-atrophic as well as atrophic arterial segments. Within such segments Langhans giant cells were found in all layers of the wall. Electron microscopy of biopsies displaying the focal foreign body reaction revealed that large cells devoid of lysosomes but with cytoplasmic densities, tightly packed cytoplasmic filaments and numerous micropinocytotic vesicles formed clusters close to calcified parts of the internal elastic membrane. Furthermore, foreign body giant cells were surrounded by large cells devoid of lysosomes. Lysosomes tended to concentrate in central parts of the foreign body giant cells. In the diffusely inflamed arteries, the Langhans giant cells were surrounded by mononuclear cells rich in lysosomes. The lysosomes in the Langhans giant cells were more evenly distributed than in foreign body giant cells. Immunocytochemistry of biopsies displaying the focal granulomatous reaction revealed an uneven, often central immunoreactivity for the macrophage marker (KP1) in the foreign body giant cells, and immunostaining for alpha-smooth muscle antigen (alpha-SMA) showed their poor delineation from the surrounding vascular smooth muscle cells. The Langhans giant cells in the diffusely inflamed arteries displayed a strong even cytoplasmic immunoreactivity for KP1 and a distinct delineation from the smooth muscle cells in the alpha-SMA staining. CONCLUSION: Differences in terms of distribution, light microscopy, immunocytochemistry and electron microscopy between the two types of giant cells in GCA indicate a difference in their function as well as their histogenesis.

Estrogen receptors in giant cell arteritis. An immunocytochemical, western blot and RT-PCR study.

OBJECTIVE: Giant cell arteritis (GCA) is a chronic form of vasculitis which predominantly affects women over 50 years of age. The aim of this study was to analyse the presence of estrogen receptor alpha (ER) in the temporal arteries of patients with GCA. METHODS: Inflamed temporal artery biopsies from 43 GCA patients were stained with monoclonal antibodies to two different segments of the ER and compared with non-inflamed arteries from age- and sex-matched controls who had not received a clinical diagnosis of GCA. The protein that was extracted from 4 GCA-positive biopsies and 4 non-GCA controls was analysed using the Western blot method with a monoclonal antibody to ER. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis using primer pairs specific to ER-cDNA was performed on the total RNA from 4 GCA-positive biopsies and 4 non-GCA controls. RESULTS: The inflamed arteries expressed distinct cytoplasmic immunoreactivity to ER in activated mononuclear inflammatory cells and in giant cells. Biopsies from GCA patients and controls displayed cytoplasmic ER positivity in smooth muscle cells. Western blot analysis revealed two bands corresponding to approximately 64 and 54 kDa, respectively, in the inflamed arteries and controls. In the inflamed biopsies and non-GCA controls, RT-PCR analysis revealed a strong band corresponding to approximately 670 bp, as expected, and a weaker band corresponding to approximately 440 bp. CONCLUSION: In inflamed arteries from GCA patients, smooth muscle cells, activated mononuclear inflammatory cells and giant cells express cytoplasmic ER. Non-inflamed control arteries also express cytoplasmic ER in smooth muscle cells. The accumulation of cytoplasmic ER may suggest the involvement of estrogen not only in GCA but also in normal vascular aging. The results justify further investigations into the pathogenetic roles of estrogen metabolism in GCA.

Estrogen receptor alpha in giant cell arteritis: a molecular genetic study.

OBJECTIVE: Giant cell arteritis (GCA) predominantly affects postmenopausal women. Estrogen receptor alpha (ER alpha) accumulates in the cytoplasm of smooth muscle cells, activated mononuclear inflammatory cells and giant cells in the temporal arteries of GCA patients, as well as in smooth muscle cells in arteries from non-GCA controls. The aim of this study was to analyse whether this accumulation is related to structural aberrations in the ER alpha mRNA leading to a change in protein structure. METHODS: Total RNA was extracted from inflamed temporal artery tissue in two GCA patients and from non-inflamed arteries in two non-GCA controls. Products from the nested RT-PCR of the cDNA were cloned and plasmid inserts of 20 different clones from each case were investigated using nucleotide sequence analysis. RESULTS: A total of eight different types of transcripts lacking parts of the ER alpha mRNA were detected. Seven of these could be explained by alternative splicing. There were no significant differences between the GCA patients and the non-GCA controls in terms of the number of transcript variants. CONCLUSION: The accumulated cytoplasmic ER alpha in temporal arterial tissue from elderly persons appears mainly to be of wild type. The main structural changes in the ER alpha mRNA may be due to alternative splicing. Somatic mutations of the ER alpha gene appear to be rare and it is therefore unlikely that they are involved in the pathogenesis of GCA.

Calcification of the internal elastic membrane in temporal arteries: its relation to age and gender.

OBJECTIVE: To investigate the age and sex distribution of calcifications of the internal elastic membrane (IEM) in temporal arteries. METHODS: Calcifications of the IEM were assessed light-microscopically in temporal arteries from 40 women and 21 men, aged 51 or more, who were known not to have giant cell arteritis (GCA). Their relation to age and the difference between women and men were tested statistically. RESULTS: The IEM calcifications differed morphologically from the calcifications in Mönckeberg's mediosclerosis and atherosclerosis. They increased significantly with age and were 2.62 times more common in women than men. CONCLUSION: Previous morphological studies indicate that the inflammatory process in GCA is initiated by a foreign-body, giant-cell attack on calcifications of the IEM. The present study showed that IEM calcifications in non-GCA controls show an age and sex distribution similar to that of GCA morbidity. The results may indicate that the presence of IEM calcifications in the general population influences the age and sex distribution of GCA. Furthermore, the findings support the hypothesis that the calcifications, although not disease specific, may play a pathogenetic role in the latter.

Giant cell arteritis. Epidemiology and treatment.

Giant cell arteritis (GCA) was considered a rare disease 50 years ago; however, it is now known to be an important and significant cause of morbidity and mortality in elderly people. GCA is a generalised arteritis, although the aetiology and pathogenesis of this disorder are poorly understood. It is likely that there are environmental or genetic factors that significantly influence the risk for the disease in different populations. Epidemiological studies have shown the highest incidence in Northern Europe and in Minnesota, US; which are populations of the same descent. Much lower incidence figures have been reported from more Southern regions of Europe and elsewhere. Possibly, the incidence of the disease is increasing as suggested by recent surveys. Glucocorticosteroids are the drugs of choice in all clinical types of GCA. Most studies have been performed with prednisolone. There is no general agreement concerning the initial dosage, but 10 to 40 mg/day is commonly recommended. After a few months the majority of patients can be treated with a low maintenance dosage of prednisolone 5 to 7.5 mg/day. Because of the low dosage required, the frequency of corticosteroid-related adverse effects is relatively low. The median duration of treatment is about 5 years. Nonsteroidal anti-inflammatory drugs, in contrast to corticosteroids, have no proven preventive effect on vascular complications of GCA, and cannot be recommended.

The influence of sectional interval on the reliability of temporal arterial biopsies in polymyalgia rheumatica.

Temporal arterial biopsies from 27 patients with a clinical diagnosis of pure polymyalgia rheumatica (PMR) were examined using light microscopy on paraffin and plastic sections. The primary routine examination of the paraffin-embedded parts of the biopsies (biopsy length: 12.7 +/- 4.5 mm, sub-segments: 4.9 +/- 1.2 mm) revealed 4 positive cases, whereas the primary examination of the smaller plastic-embedded parts showed inflammation in 6 cases (biopsy length: 2.7 +/- 1.2 mm, sub-segments: 0.7 +/- 0.3 mm). Serial sectioning with a 50 microns interval of arteries which were negative primarily revealed three new positive cases in the paraffin-embedded material (total length: 174.0 mm), whereas sectioning the plastic-embedded material (total length: 52.8 mm) produced one more positive artery. All the new cases displayed a focal inflammatory process in atrophic, calcified arterial segments. The high yield of positive biopsies in the present material (11 of 27; 40.7%) demonstrates the diagnostic value of temporal arterial biopsy in PMR and the importance of a careful histologic examination. The results also indicate the influence of biopsy length on the yield of positive biopsies. The division of fixed temporal arterial biopsies into approximately 1-mm-long sub-segments before the embedding and the further serial sectioning of those negative biopsies which are atrophic and/or calcified is recommended in cases of pure PMR.

Bone mineral content of the third lumbar vertebra during 18 months of prednisolone treatment for giant cell arteritis.

Altogether forty-four patients with giant cell arteritis (GCA) were randomly allocated to either daily morning or alternate-day administration of prednisolone. The BMC of the third lumbar vertebra was determined using dual photon absorptiometry. At least ten measurements were performed in each patient during a period of 18 months. During the course of treatment there was no significant change of the mean BMC in either group compared to the pre-treatment value. The changes of BMC were independent of such potentially explanatory variables as cumulative dose of prednisolone, initial BMC, sex and body weight. Corticosteroid treatment in patients with GCA, in the doses used by us, does not appear to cause excessive bone loss.

2015 Recommendations for the management of polymyalgia rheumatica: a European League Against Rheumatism/American College of Rheumatology collaborative initiative

Therapy for polymyalgia rheumatica (PMR) varies widely in clinical practice as international recommendations for PMR treatment are not currently available. In this paper, we report the 2015 European League Against Rheumatism (EULAR)/American College of Rheumatology (ACR) recommendations for the management of PMR. We used the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology as a framework for the project. Accordingly, the direction and strength of the recommendations are based on the quality of evidence, the balance between desirable and undesirable effects, patients' and clinicians' values and preferences, and resource use. Eight overarching principles and nine specific recommendations were developed covering several aspects of PMR, including basic and follow-up investigations of patients under treatment, risk factor assessment, medical access for patients and specialist referral, treatment strategies such as initial glucocorticoid (GC) doses and subsequent tapering regimens, use of intramuscular GCs and disease modifying anti-rheumatic drugs (DMARDs), as well as the roles of non-steroidal anti-rheumatic drugs and non-pharmacological interventions. These recommendations will inform primary, secondary and tertiary care physicians about an international consensus on the management of PMR. These recommendations should serve to inform clinicians about best practices in the care of patients with PMR.(AU)