Trends in severe outcomes in SARS-CoV-2-positive hospitalized patients with rheumatic diseases: a monocentric observational and case-control study in northern Italy.

Rheumatic disease patients are at greater risk of infection due to their disease, comorbidities, and immunosuppressive therapy. COVID-19 outcomes in this patient setting appeared to be similar to those of the general population. However, data on this topic were mainly related to small studies on a limited number of patients. Consequently, to date, this field remains poorly explored, particularly in the pre-vaccine era. This monocentric study aimed to describe the intrahospital mortality in rheumatic patients with SARS-CoV-2 consecutively hospitalized from 21 February to 31 December 2020, before anti-SARS-CoV-2 vaccine administration spread, compared with non-rheumatic patients. Of 2491 included patients, 65 [3%, median (interquartile range) age 75 (64.76-82.239 years, 65% women] were suffering from rheumatic diseases. A total of 20 deaths were reported [case fatality rate 31%, 95% confidence interval (CI): 19-42] compared with 433 deaths (19%, 95% CI: 17-20) in patients without rheumatic diseases (p=0.024). However, the rheumatic disease was not associated with a significant increase in univariate mortality hazards (hazard ratio 1.374, 95% CI: 0.876-2.154), and after adjustment (hazard ratio 1.199, 95% CI: 0.759-1.894) by age, sex and Charlson comorbidity index. The incidence of intensive care unit admission, death, and discharge in the case-control study was comparable between rheumatic and non-rheumatic patients. The presence of rheumatic diseases in SARS-CoV-2-hospitalized patients did not represent an independent risk factor for severe disease or mortality.

Innovative and conventional "conservative" technologies for the treatment of uterine fibroids in Italy: a multidimensional assessment.

BACKGROUND: To evaluate the potential benefits of the Magnetic Resonance-guided high intensity Focused Ultrasound (MRgFUS) introduction in the clinical practice, for the treatment of uterine fibroids, in comparison with the standard "conservative" procedures, devoted to women who wish to preserve their uterus or enhance fertility: myomectomy and uterine artery embolization (UAE). METHODS: A Health Technology Assessment was conducted, assuming the payer's perspective (Italian National Healthcare Service). The nine EUnetHTA Core Model dimensions were deeply investigated, by means of i) a literature review; ii) the implementation of health economics tools (useful for uterine fibroids patients' clinical pathway economic evaluation, and budget impact analysis), to define MRgFUS economic and organizational sustainability, and iii) administration of specific questionnaires filled by uterine fibroids' experts, to gather their perceptions on the three possible conservative approaches (MRgFUS, UAE and myomectomy). RESULTS: Literature revealed that MRgFUS would generate several benefits, from a safety and an efficacy profile, with significant improvement in symptoms relief. Advantages emerged concerning the patients' perspective, thus leading to a decrease both in the length of hospital stay (p-value< 0.001), and in patients' productivity loss (p-value = 0.024). From an economic point of view, the Italian NHS would present an economic saving of - 6.42%. A positive organizational and equity impact emerged regarding the capability to treat a larger number of women, thus performing, on average, 131.852 additional DRGs. CONCLUSIONS: Results suggest that MRgFUS could be considered an advantageous technological alternative to adopt within the target population affected by uterine fibroids, demonstrating its economic and organisational feasibility and sustainability, with consequent social benefits.

Sick leave request following anti-COVID-19 vaccine administration is low among healthcare workers: results from a retrospective cross-sectional monocentric study.

OBJECTIVE: Anti-COVID-19 vaccines were mainly associated with non-serious adverse events (AEs), whose prevalence was reported to be up to 70% in healthcare workers (HCWs). This may lead to sick leave requests, but this impact has never been quantified. This study aimed to investigate the absence from work among HCWs following anti-COVID-19 vaccination. Its association with age and previous COVID-19 infection was also assessed. PATIENTS AND METHODS: This is a retrospective observational cross-sectional study on administrative data about sick leave requests after anti-COVID-19 vaccination. All the HCWs employed at the Niguarda Hospital (Milan, Italy) who received the vaccine from December 27, 2020 to February 28, 2021 were included. RESULTS: In total, 4,088 HCWs received the first dose of the vaccine and 4,043 completed the vaccination cycle. After the first injection, 1.6% of HCWs requested sick leave, while after the second injection, the number of requests significantly increased (+6.1%, p<0.001). A significant increase in sick leave was detected for those who have had SARS-CoV-2 infection after the first injection (+2.3%, p<0.001). After the second dose, a significant increase in sick leave was observed in the 20-30-year-old group compared to >30 years (+3.6%, p=0.017), if HCWs without a history of SARS-CoV-2 infection were considered. CONCLUSIONS: The requests for sick leave among HCWs following the anti-COVID-19 vaccine were limited and higher after the second injection. This may help the management of the human resources when the large-scale administration of the anti-COVID-19 vaccines will involve other categories of workers.

Characterization of innate immune response to Brucella melitensis infection in goats with permissive or restrictive phenotype for Brucella intramacrophagic growth.

Caprine brucellosis is a chronic, world-wide distributed disease which causes reproductive failure in goats and Brucella melitensis, its causative agent, bears a great zoonotic potential. There is evidence suggesting that some cattle and pigs have an innate ability to resist Brucella infection, but this has not yet been investigated in goats. In this study, we compared caprine macrophages that exhibit extreme restriction and permissiveness to B. melitensis' intracellular growth in vitro. Monocyte derived macrophages (MDMs) from 110 female goats were cultured and challenged in vitro with B. melitensis 16 M. After initial screening, 18 donor goats were selected based on their macrophages ability to restrict or allow bacterial intracellular growth and some elements of humoral and cellular immunity were studied in depth. MDMs that were able to restrict the pathogen's intracellular growth showed enhanced bacterial internalization, although there were no differences between groups in the production of reactive oxygen and nitrogen intermediates following 48 h treatment with heat-killed B. melitensis. Moreover, there were no differences between groups in the level of antibodies reacting with keyhole limpet hemocyanin (natural antibodies, NAbs) or with Brucella LPS antigens (cross-reacting antibodies, CrAbs), although a strong positive correlation between individual levels of IgM NAbs and IgM CrAbs was detected. Altogether, these results represent an initial step in understanding innate primary host response to B. melitensis, and deciphering which mechanisms may determine a successful outcome of the infection in goats.

Host factors and history of SARS-CoV-2 infection impact the reactogenicity of BNT162b2 mRNA vaccine: results from a cross-sectional survey on 7,014 workers in healthcare.

OBJECTIVE: This study aimed to improve the post-marketing surveillance on mRNA anti-SARS-CoV-2 vaccines, characterizing the adverse events (AEs) after the first dose of mRNA BNT162b vaccine. The associations between the AEs and individuals' characteristics were explored. PATIENTS AND METHODS: All adult healthcare workers at Niguarda Hospital (Milan, Italy) who were referred for the first dose of vaccine were offered to participate in a cross-sectional survey during the second-dose administration, between 18 January and 7 February 2021. All participants completed a questionnaire about age, gender, weight, height, medical history, concurrent therapies, employment status, previous diagnosis/testing for SARS-CoV-2 infection, and a list of 24 AEs (solicited AEs). The development of at least one solicited AEs was the main outcome. AEs were stratified by the presence of injection-site symptoms, systemic symptoms or both, and the differences between strata were assessed as a secondary outcome. Biometric data and reports of a previous diagnosis of SARS-CoV-2 infection were also explored, as predictors of the main outcome. RESULTS: 7,014 healthcare workers were included. An incidence of 3 per 10.000 persons for serious AEs following the first administration of the mRNA BNT162b vaccine was found. An association between the development of non-serious AEs with young age, female gender, low body mass index, and previous history of SARS-CoV-2 was described. CONCLUSIONS: This real-life study supported data on the safety profile of the BNT162b2 mRNA vaccine. Our findings on the associations between the development of non-serious AEs with some individual characteristics may help physicians and patients make educated and informed medical decisions towards anti-COVID-19 vaccination.

Association of TNF rs668920841 and INRA111 polymorphisms with caprine brucellosis: A case-control study of candidate genes involved in innate immunity.

Caprine brucellosis is an infectious, contagious zoonotic disease caused by Brucella melitensis. Multiple factors, including host genetics, can influence the outcome of the exposure to Brucella; and it is expected that genetic variants that affect the host innate immune response could have a key role in Brucella infection and pathogenesis. In this study, we evaluated if polymorphisms in innate immunity-related genes are associated with results of Brucella infection in goats. Nine polymorphisms within interferon gamma (IFNG), tumor necrosis factor (TNF), MyD88 innate immune signal transduction adaptor (MYD88), interleukin 10 (IL10) and IL-10 receptor subunit alpha (IL10RA) genes and two molecular markers (BMS2753 and INRA111) were resolved by PCR-capillary electrophoresis in samples from 81 seronegative and 61 seropositive goats for brucellosis. A heterozygous genotype at INRA111, a microsatellite near the VRK serine/threonine kinase 2 (VRK2) gene, was associated with absence of Brucella-specific antibodies in goats naturally exposed to the pathogen (P = .004). Conversely, variants in the TNF gene (rs668920841) and near the IFN gamma receptor 1 (IFNGR1) gene (microsatellite BMS2753) were significantly associated with presence of Brucella-specific antibodies at allelic (P = .042 and P = .046) and genotypic level (P = .012 and P = .041, respectively). Moreover, an in silico analysis predicted a functional role of the insertion-deletion polymorphism rs668920841 on the transcriptional regulation of the caprine TNF gene. Altogether, these results contribute to the identification of genetic factors that have a putative effect on the resistance / susceptibility phenotype of goats to Brucella infection.

RNA editing signature during myeloid leukemia cell differentiation.

Adenosine deaminases acting on RNA (ADARs) are key proteins for hematopoietic stem cell self-renewal and for survival of differentiating progenitor cells. However, their specific role in myeloid cell maturation has been poorly investigated. Here we show that ADAR1 is present at basal level in the primary myeloid leukemia cells obtained from patients at diagnosis as well as in myeloid U-937 and THP1 cell lines and its expression correlates with the editing levels. Upon phorbol-myristate acetate or Vitamin D3/granulocyte macrophage colony-stimulating factor (GM-CSF)-driven differentiation, both ADAR1 and ADAR2 enzymes are upregulated, with a concomitant global increase of A-to-I RNA editing. ADAR1 silencing caused an editing decrease at specific ADAR1 target genes, without, however, interfering with cell differentiation or with ADAR2 activity. Remarkably, ADAR2 is absent in the undifferentiated cell stage, due to its elimination through the ubiquitin-proteasome pathway, being strongly upregulated at the end of the differentiation process. Of note, peripheral blood monocytes display editing events at the selected targets similar to those found in differentiated cell lines. Taken together, the data indicate that ADAR enzymes play important and distinct roles in myeloid cells.

Position statement on radiopharmaceutical production for clinical trials.

The EU regulation 536/2014 aims to facilitate the experimental use of diagnostic radiopharmaceuticals in particular for GMP requirements and needs to be applied in EU countries. As definitely clarified by this survey, the application is still far from being completed due to national restrictions that are conflicting with the content of the above EU regulation. Although the nuclear medicine centers are obliged to be compliant with national regulatory, national authorities have to be required to work towards full application of the regulation. On the other hand, an update of 536/2014 that includes therapeutic radiopharmaceuticals would also be beneficial to a rational and safe advance of nuclear medicine.

Potential impact of the 70-gene signature in the choice of adjuvant systemic treatment for ER positive, HER2 negative tumors: a single institution experience.

PURPOSE: We investigated in a single institution series of 124 women with operable breast cancer whether tumor clinicopathological features could predict the 70-gene signature (Mammaprint, MP) results, and whether MP results could help to make decisions for the use of chemotherapy (CT) in patients (pts) with ER positive breast cancer beyond recommendations of international guidelines. RESULTS: Among the 68 ER/PgR positive, HER2 negative tumors, Ki-67 ≥ 20% was the only significant predictor of a high risk-MP among standard clinicopathological features. In candidates for endocrine therapy with undetermined benefit from CT according to international guidelines, MP results would have led to different treatment decisions in 13/46 (28%) and in 20/68 (29%) pts according to NCCN and St. Gallen recommendations, respectively. CONCLUSIONS: Ki-67 independently predicted high risk-MP in ER/PgR positive, HER2 negative tumors. MP results would have led to discordant treatment recommendations in about 30% of cases, generally increasing indication rate for CT. The results of large randomized trials are warranted in order to understand whether we should rely on multigene assays rather than on standard clinicopathological features for treatment decisions.

ADAR2-editing activity inhibits glioblastoma growth through the modulation of the CDC14B/Skp2/p21/p27 axis.

Grade IV astrocytoma or glioblastoma multiforme (GBM) is one of the most aggressive and lethal tumors affecting humans. ADAR2-mediated A-to-I RNA editing, an essential post-transcriptional modification event in brain, is impaired in GBMs and astrocytoma cell lines. However, the role of ADAR2 editing in astrocytomas remains to be defined. Here, we show that ADAR2 editing rescue in astrocytomas prevents tumor growth in vivo and modulates an important cell cycle pathway involving the Skp2/p21/p27 proteins, often altered in glioblastoma. We demonstrate that ADAR2 deaminase activity is essential to inhibit tumor growth. Indeed, we identify the phosphatase CDC14B, which acts upstream of the Skp2/p21/p27 pathway, as a novel and critical ADAR2 target gene involved in glioblastoma growth. Specifically, ADAR2-mediated editing on CDC14B pre-mRNA increases its expression with a consequent reduction of the Skp2 target protein, as shown both in vitro and in vivo. We found that, compared to normal brain, both CDC14B editing and expression are progressively impaired in astrocytomas from grade I to IV, being very low in GBMs. These findings (1) demonstrate that post-transcriptional A-to-I RNA editing might be crucial for glioblastoma pathogenesis, (2) identify ADAR2-editing enzyme as a novel candidate tumor suppressor gene and (3) provide proof of principle that ADAR2 or its substrates may represent a suitable target(s) for possible novel, more effective and less toxic approaches to the treatment of GBMs.

Genetic analysis of the 3' untranslated region of the bovine SLC11A1 gene reveals novel polymorphisms.

Polymorphisms in microsatellites at the 3' untranslated region (3'UTR) of the SLC11A1 (solute carrier family 11 member A1) gene have been associated with natural resistance to Brucella abortus and Mycobacterium bovis infection in livestock species. Here, we carried out an individual genetic analysis of the two microsatellites present at the 3'UTR SLC11A1 gene in 254 Bos taurus purebred, 125 B. indicus purebred and 54 B. taurus × B. indicus crossbred cattle. The genotyping by capillary electrophoresis showed the presence of four alleles (157, 159, 161 and 163) for the first microsatellite (MS1) and six alleles (175, 177, 179, 181, 183 and 185) for the second microsatellite (MS2). The alleles 159 and 175 were the most frequent in all breeds analyzed. B. taurus showed the most homogeneous haplotype and genotype for both microsatellites, whereas B. indicus showed the most heterogeneous haplotype and genotype. Two novel variants (alleles 161 and 163) within the MS1 are reported as well as novel variants in MS2 in Holstein breed. The knowledge of the polymorphisms distribution in both microsatellites at the 3'UTR of the SLC11A1 gene in cattle breeds is useful for future experimental design to evaluate the association between reported genotypes and natural resistance to pathogens infection.

Comparative analysis of the early transcriptome of Brucella abortus--infected monocyte-derived macrophages from cattle naturally resistant or susceptible to brucellosis.

Brucellosis is a worldwide zoonotic infectious disease that has a significant economic impact on animal production and human public health. We characterized the gene expression profile of B. abortus-infected monocyte-derived macrophages (MDMs) from naïve cattle naturally resistant (R) or susceptible (S) to brucellosis using a cDNA microarray technology. Our data indicate that (1) B. abortus induced a slightly increased genome activation in R MDMs and a down-regulated transcriptome in S MDMs, during the onset of infection, (2) R MDMs had the ability to mount a type 1 immune response against B. abortus infection which was impaired in S cells, and (3) the host cell activity was not altered after 12 h post-B. abortus infection in R MDMs while the cell cycle was largely arrested in infected S MDMs at 12 h p.i. These results contribute to an improved understanding of how host responses may be manipulated to prevent infection by brucellae.

Genomic characterization and chromosomal mapping of 5 river buffalo skeletal muscle differentiation master genes.

River buffalo (Bubalus bubalis, 2n = 50, BBU) is a species of economic relevance in a number of countries. This species shows a very peculiar biology and a great capacity for environmental adaptation. There has been an increasing economic interest as well as a growing demand for a more detailed knowledge of molecular features in this species. From this perspective we report a genomic, transcriptional and cytogenetic analysis of 5 master genes involved in skeletal muscle development. Of these 5 genes, MYOD1, MYF5, MYF6 and MYOG belong to the basic helix-loop helix protein family while MSTN belongs to the TNF-B protein family. In mammals, these genes are involved in the early stages of skeletal muscle differentiation, development and regeneration. These pivotal biological functions are finely regulated in a tissue- and temporal-specific manner. We used a comparative genomic approach to obtain the buffalo specific sequences of MYOD1 and MYF6. The nucleotide sequence similarity and the protein domain conservation of the newly obtained sequences are analysed with respect to bovine and other mammalian species showing sequence similarity. The presence of a polymorphism in MYOD1 coding sequence is described and its possible effect discussed. Using a quantitative PCR approach, we compared the level of the 5 transcripts in adult and fetal muscle. These genes were physically localised on river buffalo R-banded chromosomes by FISH using bovine genomic BAC-clones. Here, we present a genomic and cytogenetic analysis which could offer a background to better characterise the buffalo genes involved in muscle function and which may be responsible for buffalo-specific meat features.

Brown fat uptake of 18F-FDG on dual time point PET/CT imaging.

The aim of this report was to assess the changes in the 18F-fluorodeoxyglucose (18F-FDG) uptake of brown fats on integrated positron emission tomography/computed tomography (PET/CT) imaging. The patient presented with an enlargement of the neck lymph nodes, and was suspicious for tuberculous lymphadenitis. A whole body PET/CT imaging was performed, followed by a delayed imaging of the neck and thoracic regions. A visually increased 18F-FDG uptake was taken as a positive finding. A semi-quantitative evaluation was performed using a maximum standardised uptake value (SUVmax), with a cut-off value above 2.5. There were a number of 18F-FDG avid activity areas seen at the supraclavicular, mediastinal, paravertebral and perirenal regions. These are in keeping with the physiological 18F-FDG uptake in brown fat. The differences in SUVmax between the two images ranged from -20 percent to +20 percent. Based on our observations, dual time point imaging may not be a reliable method for assessing the 18F-FDG uptake of brown fat.

Morphologic and cytokine profile characterization of Salmonella enterica serovar typhimurium infection in calves with bovine leukocyte adhesion deficiency.

The role of neutrophils in the pathogenesis of Salmonella enterica Typhimurium-induced ruminant and human enteritis and diarrhea has yet to be characterized with in vivo models. To address this question, the in vivo bovine ligated ileal loop model of nontyphoidal salmonellosis was used in calves with the naturally occurring bovine leukocyte adhesion deficiency (BLAD) mutation whose neutrophils are unable to extravasate and infiltrate the extravascular matrix. Data obtained from 4 BLAD Holstein calves homozygous for BLAD (CD18-), 1 to 5 weeks of age, were compared with 4 controls, age-matched Holstein calves negative for BLAD (CD18+). Morphologic studies revealed that infection of CD18- calves with S Typhimurium resulted in no significant tissue infiltration by neutrophils, less tissue damage, reduced luminal fluid accumulation, and increased bacterial invasion, when compared with CD18+ calves. Ultrastructurally, lesions in enterocytes induced by S Typhimurium infection in CD18- calves--including attachment and disruption of the brush border, apical membrane ruffling formation, and cellular degeneration--were similar to the ones reported in the literature for CD18- calves. Study of cytokine gene expression by quantitative real-time polymerase chain reaction revealed that early stages of acute infection (4-8 hours postinfection) were associated with increased interleukin 8 gene expression in the absence of tissue influx of neutrophils in CD18- calves, whereas later stages of infection (12 hours postinfection) were associated with increased expression of growth-related oncogene alpha in the presence of neutrophil influx in CD18+ calves. In contrast, the proinflammatory cytokines interleukin 1beta and tumor necrosis factor alpha were poorly correlated with the presence or absence of tissue neutrophils.

Early phase morphological lesions and transcriptional responses of bovine ileum infected with Mycobacterium avium subsp. paratuberculosis.

Mycobacterium avium subsp. paratuberculosis (MAP) is the causative agent of chronic enteritis in ruminants (Johne's disease) and a possible etiopathologic agent in human Crohn's disease. The host-pathogen interaction in this chronic disease has largely depended on the randomly collected static lesions studied in subclinically or clinically infected animals. We have established and utilized the neonatal calf ligated ileal loop model to study the early temporal host changes during MAP infection. After inoculation of ligated ileal loop with MAP, samples were analyzed for bacterial invasion, histologic and ultrastructural morphologic changes, and gene expression at several times (0.5-12 hours) postinfection. Our results indicate that MAP invades the intestinal mucosa as early as 0.5 hour postinoculation. Distribution and migration of neutrophils, monocytes/macrophages, and goblet cells were confirmed by histopathology, scanning and transmission electron microscopy. Coincident with the morphologic analysis, we measured by real-time polymerase chain reaction gene expression of various cytokines/chemokines that are involved in the recruitment of mononuclear and polymorphonuclear leukocytes to the site of infection. We also detected expression of several other genes, including intestinal-trefoil factor, profilin, lactoferrin, and enteric ss-defensin, which may play significant roles in the early MAP infection. Thus, the calf ligated intestinal loop model may be used as a human disease model to understand the role of MAP in the pathogenesis of Crohn's disease.

PET-CT as an effective imaging modality in the staging and follow-up of post-transplant lymphoproliferative disorder following solid organ transplantation.

INTRODUCTION: To establish the role of positron-emission tomography (PET)-computed tomography (CT) in post-transplant lymphoproliferative disorder (PTLD) patients, compared to conventional imaging (ultrasonography/CT/magnetic resonance imaging) in relation to its accuracy, sensitivity and specificity. METHODS: 30 patients (26 males and 4 females), with a median age of 49.5 (range 18-74) years, were retrospectively evaluated. In 29 cases, the diagnosis was confirmed by histopathology. Malignant lymphoma was detected in 20 cases, polymorphic lymphoproliferative disorder in six cases, multiple myeloma in two cases and Hodgkin's disease in one case. A total of 49 PET-CTs (13 studies for staging at diagnosis and 36 studies at follow-up as assessment post-therapy) were compared to conventional imaging. Imaging results in accordance with disease status were assessed at a median follow-up of 17.8 (range 1.5-42.2) months post-PET-CT. RESULTS: In 41 of 49 examinations performed for staging and on follow-up, PET-CT and conventional imaging findings were concordant. Compared to conventional imaging, PET-CT showed comparable sensitivity (75 percent vs. 83 percent), similar specificity (100 percent in both modalities) and comparable accuracy (77 percent vs. 85 percent) during staging at diagnosis. PET-CT was found to be superior to conventional imaging modalities at follow-up, with greater sensitivity (100 percent vs. 81 percent), specificity (80 percent vs. 100 percent) and accuracy (97 percent vs. 83 percent). CONCLUSION: PET-CT is an accurate diagnostic tool for staging and for the follow-up of PTLD patients. It represents a good alternative imaging method to avoid contrast-related nephrotoxicity in patients who often develop impaired renal function secondary to chronic immunosuppressive therapy. However, further studies are recommended before considering PET-CT as a routine diagnostic tool in PTLD.

Long-term preservation of leptospiras by liquid nitrogen.

Liquid nitrogen freezing is recommended for long-term preservation of Leptospira serovars. However, there is no standard protocol to follow for this methodology. We herein report a simple procedure to preserve well-characterized Leptospira serovars unaltered for long-term storage in liquid nitrogen. Forty-three (43) leptospira strains, cryoprotected with 10% (v/v) glycerol were rapidly frozen in a dry-ice methanol bath and immediately submerged in liquid-nitrogen. Viability was retained in 100%, 93% and 83% of the frozen cultures after 6, 18 and 54 months, following freezing and storage in liquid nitrogen, respectively. Motility and agglutinability were not altered. These results demonstrate the usefulness of this protocol for long-term storage of genus Leptospira in liquid nitrogen.

18F-FDG positron emission tomography/computed tomography and the "underground map" appearance in imaging Horton's arteritis.

A majority of the clinical use of positron emission tomography (PET)-computed tomography (CT) is related to cancer management. Its application in evaluating inflammatory diseases and pyrexia of unknown origin is becoming popular. We reviewed the fluorine-18-fluorodeoxyglucose PET-CT findings of an 80-year-old woman with nonspecific clinical presentation consisting of generalised malaise, moderately high fever and weight loss. Prior CT and magnetic resonance imaging were not helpful in providing a clinical diagnosis. The diagnosis was Horton's arteritis, and the patient responded well to high-dose steroids.