Clinical and laboratory findings with giant cell arteritis

Cerebral amyloid angiopathy and related inflammatory disorders

Inflammatory cerebral amyloid angiopathy is a largely reversible inflammatory vasculopathy that develops in an acute or subacute fashion in reaction to amyloid protein deposition in the central nervous system blood vessels. There are two recognized pathologically characterized variants: cerebral amyloid angiopathy-related inflammation (CAAri) and A beta-related angiitis (ABRA). Both variants produce a clinical picture that resembles primary angiitis of the CNS but is distinguished by a characteristic radiologic appearance. Although originally defined as a clinicopathologic diagnosis, it can now often be diagnosed based on clinicoradiologic criteria, though confirmation with brain and meningeal biopsy is still required in some cases. This disorder typically responds to steroids but addition of other immune suppressants may be needed in some cases to control the disease.

Giant Cell Arteritis and COVID-19: Similarities and Discriminators. A Systematic Literature Review

OBJECTIVE

To identify shared and distinct features of giant cell arteritis (GCA) and coronavirus disease 2019(COVID-19) to reduce diagnostic errors that could cause delays in correct treatment.

METHODS

Two systematic literature reviews determined the frequency of clinical features of GCA and COVID-19 in published reports. Frequencies in each disease were summarized using medians and ranges.

RESULTS

Headache was common in GCA but was also observed in COVID-19 (GCA 66%, COVID-19 10%). Jaw claudication or visual loss (43% and 26% in GCA, respectively) generally were not reported in COVID-19. Both diseases featured fatigue (GCA 38%, COVID-19 43%) and elevated inflammatory markers (C-reactive protein [CRP] elevated in 100% of GCA, 66% of COVID-19), but platelet count was elevated in 47% of GCA but only 4% of COVID-19 cases. Cough and fever were commonly reported in COVID-19 and less frequently in GCA (cough, 63% for COVID-19 vs 12% for GCA; fever, 83% for COVID-19 vs 27% for GCA). Gastrointestinal upset was occasionally reported in COVID-19 (8%), rarely in GCA (4%). Lymphopenia was more common in COVID-19 than GCA (53% in COVID-19, 2% in GCA). Alteration of smell and taste have been described in GCA but their frequency is unclear.

CONCLUSION

Overlapping features of GCA and COVID-19 include headache, fever, elevated CRP and cough. Jaw claudication, visual loss, platelet count and lymphocyte count may be more discriminatory. Physicians should be aware of the possibility of diagnostic confusion. We have designed a simple checklist to aid evidence-based evaluation of patients with suspected GCA.

Systemic diseases and disorders

Alterations in the ability to smell or taste are of considerable consequence, impacting quality of life, safety, nutrition, and dietary activities. These primary senses are influenced by a wide range of systemic diseases and disorders that commonly involve the entire body. These include viral, bacterial, fungal, protozoal, cestode, and nematode infections that can spread throughout the gastric, lymphatic, neural, or circulatory systems as well as classic autoimmune disorders, collagen diseases, diabetes, and hypertension, and others. Although a considerable literature has evolved in which the function of both taste and smell has been assessed in a number of such disorders, quantitative chemosensory testing is still relatively rare with many disorders not receiving empirical assessment. Incongruent findings are not uncommon. This chapter reviews what is known about the influences of a wide spectrum of systemic diseases and disorders on the abilities to taste and smell.

Neuro-Ophthalmic Complications of Biopsy-Proven Giant Cell Arteritis

Purpose

To define the spectrum of neuro-ophthalmic complications and clinical presentations of patients with giant cell arteritis (GCA).

Methods

Retrospective study (1977-1994) of clinical charts, fundus photographies and fluorescein angiographies of 66 patients with temporal artery biopsy positive for GCA.

Results

Clinical data were adquate for 47 patients. Headaches were reported by 83%, weight loss in 73%, jaw claudication in 68%, scapular pain in 64% and asthenia in 57%. Erythrocyte sedimentation rate was normal in 15%. Neuro-ophthalmic complications were present in 33 cases (70%), including anterior ischemic optic neuropathy (22 cases), choroidal ischemia (17 cases), central or branch retinal artery occlusion (seven cases), and oculomotility disturbances (four cases). Fluorescein angiography was very helpful for detecting choroidal ischemia (80.9% of our cases). Twenty-one patients presented with involvement of several distinct orbital arterial territories and one very unusual patient suffered from an orbital infarction (i.e. ischemia of all orbital structures).

Conclusions

In our series, two-thirds of biopsy-proven GCA patients presented with neuro-ophthalmic complications, ranging from transient visual loss to orbital infarction. Involvement of more than one orbital vascular territory is highly suggestive of an arteritic process. Clinicians should keep in mind the possibility of GCA even when ESR is normal, and fluorescein angiography should be performed. The finding of choroidal ischemia should prompt temporal artery biopsy and steroid therapy.

Alzheimer's disease - a neurospirochetosis. Analysis of the evidence following Koch's and Hill's criteria

It is established that chronic spirochetal infection can cause slowly progressive dementia, brain atrophy and amyloid deposition in late neurosyphilis. Recently it has been suggested that various types of spirochetes, in an analogous way to Treponema pallidum, could cause dementia and may be involved in the pathogenesis of Alzheimer's disease (AD). Here, we review all data available in the literature on the detection of spirochetes in AD and critically analyze the association and causal relationship between spirochetes and AD following established criteria of Koch and Hill. The results show a statistically significant association between spirochetes and AD (P = 1.5 × 10-17, OR = 20, 95% CI = 8-60, N = 247). When neutral techniques recognizing all types of spirochetes were used, or the highly prevalent periodontal pathogen Treponemas were analyzed, spirochetes were observed in the brain in more than 90% of AD cases. Borrelia burgdorferi was detected in the brain in 25.3% of AD cases analyzed and was 13 times more frequent in AD compared to controls. Periodontal pathogen Treponemas (T. pectinovorum, T. amylovorum, T. lecithinolyticum, T. maltophilum, T. medium, T. socranskii) and Borrelia burgdorferi were detected using species specific PCR and antibodies. Importantly, co-infection with several spirochetes occurs in AD. The pathological and biological hallmarks of AD were reproduced in vitro by exposure of mammalian cells to spirochetes. The analysis of reviewed data following Koch's and Hill's postulates shows a probable causal relationship between neurospirochetosis and AD. Persisting inflammation and amyloid deposition initiated and sustained by chronic spirochetal infection form together with the various hypotheses suggested to play a role in the pathogenesis of AD a comprehensive entity. As suggested by Hill, once the probability of a causal relationship is established prompt action is needed. Support and attention should be given to this field of AD research. Spirochetal infection occurs years or decades before the manifestation of dementia. As adequate antibiotic and anti-inflammatory therapies are available, as in syphilis, one might prevent and eradicate dementia.

Giant cell arteritis in association with cerebral amyloid angiopathy: immunohistochemical and molecular studies

Giant cell arteritis (GCA) usually manifests as a transmural vascular infiltrate of mononuclear and multinucleated giant cells (MNGC). We describe six patients with GCA associated with severe cerebral amyloid angiopathy (CAA), all with cerebral hemorrhage or varying degrees of cerebral infarct, and histological evidence of Alzheimer's disease (cortical CAA often predominating over senile plaques and neurofibrillary tangles). One case showed mostly cortical involvement (with old microhemorrhages), and the others were primarily leptomeningeal (with involvement of the underlying cortex and extensive encephalomalacia of adjacent brain). Many vessels with CAA exhibited a pronounced adventitial and perivascular infiltrate of lymphocytes, histiocytes, and MNGC. Immunohistochemical staining showed deposition of beta/A4 peptide primarily in the thickened media of CAA vessels, and within the cytoplasm of MNGC--suggesting phagocytosis of insoluble peptide. Cystatin C antibody stained vascular amyloid and diffusely highlighted astrocytic and MNGC cytoplasm. HAM56-positive macrophages were frequently seen around amyloid-laden vessels. Anti-smooth muscle actin immunohistochemistry suggests the occurrence of medial destruction by amyloid, with relative preservation of intimal cells. Ultrastructural studies performed in one case confirmed the presence of intracytoplasmic amyloid in MNGC. The GCA seen in these cases of CAA most likely represents a foreign body response to amyloid proteins, causing secondary destruction of the vessel wall. DNA from brain tissues of five affected patients was examined to assess whether mutations were present in exon 17 of the APP gene or exon 2 of the cystatin C gene, a finding that might explain the foreign body giant cell response to amyloid proteins in these cases. However, restriction fragment mapping of amplified gene segments showed that previously described mutations were not present in these cases.

Impaired inhibition in writer's cramp during voluntary muscle activation

We used paired transcranial magnetic stimulation (TMS) to evaluate inhibitory mechanisms in eight patients with writer's cramp during rest and isometric wrist extension. Both stimuli were 110% of the motor threshold; the interstimulus intervals (ISIs) were 20 to 200 ms in increments of 10 ms. Surface EMG was recorded from wrist extensors. In the symptomatic hemisphere, there was no significant difference in the amplitude of the test (second) motor evoked-potential (MEP) between patients and age-matched controls at rest. However, with voluntary muscle activation, inhibition of the test MEP by the conditioning MEP was significantly less in writer's cramp patients than in controls (p = 0.02). The difference was most prominent at ISIs of 60 to 80 ms in which inhibition is maximum. In the asymptomatic hemisphere, there was no significant difference between patients and controls in both rest and active conditions. The silent period was shorter in patients than controls on the symptomatic side (p = 0.003) but not on the asymptomatic side. We conclude that the inhibitory effects induced by magnetic stimulation are reduced in patients with writer's cramp, but only on the symptomatic side during muscle activation. This may relate to the overflow of muscle activity that characterizes this condition.

Current concepts in giant cell (temporal) arteritis

Giant cell (temporal) arteritis continues to be a sight-threatening, systemic vasculitis with a poorly understood pathogenesis. The characteristic granulomatous inflammation of the vessel wall commonly leads to local ischemia. Recent advances in immunological investigations have characterized the cellular components of the disease process, but the etiology has so far remained unresolved. A reappraisal of the clinical features of giant cell (temporal) arteritis demonstrates the heterogeneity of the manifestations of the disease, including ischemic optic neuropathy. A range of new laboratory investigations and blood flow studies with color Doppler imaging have demonstrated promising roles, with respect to diagnosis and long-term follow-up. Prompt diagnosis and expeditious treatment require a high index of clinical suspicion, particularly for atypical cases. Corticosteroids remain the treatment of choice, other immuno-suppressive agents being used as second line steroid-sparing agents. Giant cell (temporal) arteritis leads to increased vascular and visual morbidity and, if untreated, may prove fatal. To maintain high standards of management of this enigmatic disorder, ophthalmologists need to be aware of the clinical spectrum of giant cell (temporal) arteritis and currently available diagnostic tests and treatment strategies.

Polymorphism at codon 129 or codon 219 of PRNP and clinical heterogeneity in a previously unreported family with Gerstmann-Sträussler-Scheinker disease (PrP-P102L mutation)

We present a new, large, Italian family affected by Gerstmann-Sträussler-Scheinker syndrome (GSS) associated with the Pro to Leu point mutation at codon 102 of the prion protein gene (PRNP). The affected members of this family show a remarkable phenotypic variability of the disease: three of them had a clinical picture characterized by dementia and a brief illness duration (less than 1 year), while the other five members presented an ataxic, slowly evolving syndrome (a clinical duration of 3 to 4 years) with no evidence of cognitive impairment. Despite these remarkable clinical differences among affected members, we found no correlation between the clinical presentation and the codon 129 or codon 219 genotypes. These data suggest that factors as yet unidentified may influence the clinical expression of the disease.

Familial Creutzfeldt-Jakob disease with a five-repeat octapeptide insert mutation

We report a familial form of Creutzfeldt-Jakob disease, associated with a unique insert mutation of the PRNP gene in an American family of Ukrainian origin. Ten family members exhibited early age at onset and long-duration illnesses characterized primarily by personality changes, cognitive impairment, and spasticity. The proband, presenting at age 42 years, exhibited a fairly stable, nonprogressive course over 7 years, followed by precipitous decline and death in the eighth year. Other affected family members exhibited marked clinical heterogeneity. Each tested affected member had an insert mutation consisting of five extra octapeptide repeats between codons 51 and 91 of the PRNP gene on chromosome 20. Examination of two autopsy cases showed classic spongiform change, neuronal loss and astrocytosis in one case, and minimal pathologic abnormality in the other case. This report documents a new insert mutation of the PRNP gene, and confirms the early age of onset, characteristically prolonged clinical course, and clinical and pathologic heterogeneity seen in such mutations.

Polymyalgia rheumatica and giant cell arteritis

The original descriptions of polymyalgia rheumatica (PMR) and giant cell arteritis (GCA) in the medical literature date back to 1888 and 1890, respectively. Classification criteria for PMR and GCA are not standardized since most authors used subjective criteria based on their personal experience. Only one study has evaluated criteria for PMR and has found seven variables with high discriminant value. Criteria for GCA are less varied because a positive biopsy of the temporal artery is diagnostic. However, combinations of different clinical and laboratory features have been used for diagnosis when biopsy is negative or missing. Assessment of PMR/GCA is based on the serial determination of markers of acute phase such as ESR, CRP, or plasma viscosity. However, their value in predicting recurrence of the diseases is poor. New immunological factors including soluble interleukin-2 receptors, interleukin-6, serum soluble CD8, and serum soluble intercellular adhesion molecule-1 are presently under investigation.