Giant-cell arteritis-related mortality in France: A multiple-cause-of-death analysis.

Purpose Giant cell arteritis (GCA) is the most common systemic vasculitis in the elderly and can cause irreversible blindness and aortitis. Varicella zoster (VZ), which is potentially preventable by vaccination, has been proposed as a possible immune trigger for GCA, but this is controversial. The incidence of GCA varies widely by country. If VZ virus contributes to the immunopathogenesis of GCA we hypothesized that nations with increased incidence of GCA would also have increased incidence of herpes zoster (HZ). We conducted an ecologic analysis to determine the relationship between the incidence of HZ and GCA in different countries. Methods A literature search for the incidence rates (IRs) of GCA and HZ from different countries was conducted. Correlation and linear regression was performed comparing the disease IR of each country for subjects 50 years of age or older. Results We found the IR for GCA and HZ from 14 countries. Comparing the IRs for GCA and HZ in 50-year-olds, the Pearson product-moment correlation (r) was -0.51, with linear regression coefficient (β) -2.92 (95% CI -5.41, -0.43; p=0.025) using robust standard errors. Comparing the IRs for GCA and HZ in 70-year-olds, r was -0.40, with β -1.78, which was not statistically significant (95% CI -4.10, 0.53; p=0.12). Conclusion Although this geo-epidemiologic study has potential for aggregation and selection biases, there was no positive biologic gradient between the incidence of clinically evident HZ and GCA.

Does herpes zoster predispose to giant cell arteritis: a geo-epidemiologic study.

Objective The incidence of giant cell arteritis (GCA) is insufficiently documented for Canada, but important to ascertain for public health planning. We estimate the incidence of biopsy-proven GCA (BPGCA) in Kingston, Ontario, and for the province of Ontario. Method The number of cases of BPGCA was tabulated from retrospective chart review of all temporal artery biopsies (TABx) in Kingston, Ontario from 2011–15. The relevant population denominator was determined from the Canada census federal electoral district and the patient’s postal code. The province-wide estimate for the incidence of BPGCA was calculated from provincial billing data of TABx from 2015–17, the Canada census for Ontario, and the expected positive yield of TABx. Results There were 35 subjects with BPGCA in the Kingston area over the 4-year period, from a population of 179 503 individuals 50 years of age or older (≥50 years). Ontario billing data identified 2404 patients who underwent TABx for suspected GCA over a 2-year period, from a population of 5 143 610 persons ≥50 years. Meta-analysis of 5 provincial TABx series suggested a 21% positive yield from TABx procedures (95% CI 0.18–0.24). The minimum cumulative incidence of BPGCA was 4.9 per 100 000 persons ≥50 years in Kingston, and 4.9 (95% CI 4.2–5.6) per 100 000 persons ≥50 years for Ontario as a whole. Conclusion The estimated incidence of BPGCA in Ontario using 2 different estimation techniques was comparable, but low compared with other countries. The actual incidence of GCA in Ontario may be higher.

The incidence of giant cell arteritis in Ontario, Canada.

Epidemiology of major relapse in giant cell arteritis: A study-level meta-analysis

https://www.sciencedirect.com/science/article/am/pii/S1568997221002056

Knowledge of the natural history and epidemiology of giant cell arteritis (GCA) is growing. With the recent conceptual change, GCA is no longer considered a disease with mandatory cranial symptoms but, rather, a larger disease spectrum also including idiopathic aortitis in people older than 50 and polymyalgia rheumatica with large-vessel involvement. The incidence peak between age 70 and 80 years, greater frequency in females and greater occurrence in Nordic countries are well-established epidemiological characteristics. Conversely, the notion that the incidence of GCA is increasing is challenged by several recent population-based studies suggesting a trend reversal for about 15 to 20 years. The known link with the allele HLA-DRB1*04 was confirmed by a genome-wide association study that also found associations with two other genetic polymorphisms. Recent studies indicating a link with varicella zoster virus infection have invigorated the hypothesis of an infectious cause for GCA. Smoking is the most solidly recognized environmental risk factor, but other traditional cardiovascular risk factors do not seem to predispose to GCA. Evidence is mounting that overall mortality in GCA patients is at best slightly higher than expected in relation to general population mortality data, but GCA is associated with an increase in morbidity and mortality specifically related to aortic aneurysm or other cardiovascular causes. Further studies are needed to integrate the current knowledge into a single etiological model.

A. Aouba

Papers

Épidémiologie et histoire naturelle de l’artérite à cellules géantes (Horton)

Iconographies supplémentaires de l'article : Épidémiologie et histoire naturelle de l’artérite à cellules géantes (Horton)