Mortality in American Veterans with the HLA-B27 gene

Uveitis and Scleritis as a Risk Factor for Mortality

PURPOSE

Uveitis and scleritis may be caused by local or systemic infection, or associated with noninfectious systemic inflammatory autoimmune disease. This study explored the all-cause mortality following an individual's first presentation with uveitis/scleritis.

METHODS

A cross-sectional study was conducted on all uveitis/scleritis patients diagnosed by uveitis specialists and treated in a single tertiary referral center in New Zealand between 2006 and 2020(15y). Masquerade syndromes including intraocular lymphoma were excluded. Outcome measures: demographics, etiology of uveitis/scleritis, anatomical location and all-cause mortality.

RESULTS

2723 subjects were identified. Median age of onset of uveitis/scleritis was 44.9 years (Range:1.5-99.5 years). 49.6% were female. Median follow-up from diagnosis of uveitis/scleritis was 8.0 years (IQR 4.1-11.6 years) with a total follow-up of 24 443.3 subject-years. The most frequent diagnosis was idiopathic disease (30.9%), HLA-B27-positive uveitis (20.0%), and sarcoidosis (4.7%). Infectious etiologies (24.1%) were most commonly from herpes zoster virus (9.3%) and toxoplasmosis (4.3%). The age-adjusted mortality rate was higher in subjects with idiopathic disease, sarcoidosis, Fuchs' uveitis syndrome, granulomatosis with polyangiitis/ANCA-associated vasculitis, toxoplasmosis, and herpes zoster virus, when compared to HLA-B27-positive uveitis. Hazard of mortality peaked in the first seven years following diagnosis, then subsequently declined. Patients with uveitis/scleritis had a significantly higher rate of mortality compared to the general New Zealand population (IRR 1.656 p = 0.017).

CONCLUSION

Infectious etiologies of uveitis/scleritis in this cohort were high when compared to other developed nations, attributable to data from a tertiary referral center treating inpatients. Potential shared inflammatory mechanisms in the eye and other organs can lead to concurrent non-ocular disease requiring systemic treatment, impacting an individual's longevity.

HLA-B27, axial spondyloarthritis and survival

INTRODUCTION

Ankylosing spondylitis (AS), and carriage of HLA-B27 gene in otherwise healthy individuals, are reportedly associated with increased mortality. We evaluated this hypothesis, using data from both a 35-year AS follow-up study and UK Biobank data.

METHODS

In 1985, 363 members of the Swiss AS Patient Society and 806 relatives were screened clinically and then radiographically for AS/axial spondyloarthritis (axSpA). Life expectancy was analysed in 377 axSpA patients having available pelvic radiographs and HLA-B27 status, comparing with matched Swiss population data. Survival in relation to HLA-B27 status in the general population was studied in UK Biobank European-ancestry participants (n=407 480, n=30 419 deaths).

RESULTS

AS patients have increased standardised mortality rate (SMR) compared with the general population (1.37, 95% CI 1.11 to 1.62). This increase was significant for HLA-B27-positive AS (SMR 1.38, 95% CI 1.11 to 1.65). Shortened life expectancy was observed among both HLA-B27-positive AS women (SMR 1.77, 95% CI 1.09 to 2.70) and men (SMR 1.31, 95% CI 1.02 to 1.59). Patients with non-radiographic axSpA (nr-axSpA) had significantly lower SMR: 0.44 (95% CI 0.23 to 0.77), compared with the general population. In the UK Biobank European-ancestry population cohort, HLA-B27 carriage was not significantly associated with any change in mortality (HR 1, 95% CI 0.97 to 1.1, p=0.349, adjusted by sex), in either males (HR 1, 95% CI 0.98 to 1.1, p=0.281) or females (HR 0.96, 95% CI 0.9 to 1, p=0.232), and no increase in vascular disease mortality was observed.

DISCUSSION

AS patients, but not nr-axSpA patients, have a significantly shortened life expectancy. Increased mortality is particularly significant among women with HLA-B27-positive AS. HLA-B27 carriage in the European-ancestry general population does not influence survival, or the risk of death due to vascular disease.

All-Cause and Cause-Specific Mortality in Psoriatic Arthritis and Ankylosing Spondylitis: A Systematic Review and Meta-Analysis

OBJECTIVE

Psoriatic arthritis (PsA) and ankylosing spondylitis (AS) are chronic inflammatory diseases associated with a higher risk of cardiometabolic comorbidities compared to the general population. Individual studies examining mortality in these patients have produced conflicting results. The present study was undertaken to perform a systematic review and meta-analysis to analyze the all-cause and cause-specific mortality in PsA and AS from the available literature.

METHODS

A comprehensive database search was performed for studies reporting all-cause or cause-specific mortality in patients with PsA and AS compared with the general population. Pooled relative risks (RRs) were calculated using a random-effects model.

RESULTS

We included 19 studies (11 of PsA, 7 of AS, 1 of both). In PsA studies, there was no increased mortality compared to the general population (RR 1.12 [95% confidence interval (95% CI) 0.96-1.30]; n = 10 studies). We found a higher all-cause mortality in female (RR 1.19 [95% CI 1.04-1.36]) but not in male (RR 1.02 [95% CI 0.66-1.59]) PsA patients. Cardiovascular-, respiratory-, and infection-specific mortality risks were significantly higher for PsA patients (RR 1.21 [95% CI 1.06-1.38], RR 3.37 [95% CI 1.30-8.72], and RR 2.43 [95% CI 1.01-5.84], respectively), but not cancer-related mortality (RR 1.01 [95% CI 0.91-1.11]). In AS, we found a higher risk of death from all causes (RR 1.64 [95% CI 1.49-1.80]; n = 6 studies) and cardiovascular causes (RR 1.35 [95% CI 1.01-1.81]; n = 3 studies) compared to the general population. All-cause mortality was high in both male (RR 1.56 [95% CI 1.43-1.71]) and female (RR 1.85 [95% CI 1.56-2.18]) AS patients. The included AS studies did not report mortality data for non-cardiovascular causes.

CONCLUSION

This systematic review and meta-analysis showed a significantly increased risk of overall mortality in AS but not PsA. Cardiovascular-specific mortality was higher for both PsA and AS, which emphasizes the importance of early screening and management of cardiovascular risk factors.

Identifying Patients With Axial Spondyloarthritis in Large Datasets: Expanding Possibilities for Observational Research

OBJECTIVE

Observational research of axial spondyloarthritis (axSpA) is limited by a lack of methods for identifying diverse axSpA phenotypes in large datasets. Algorithms were previously designed to identify a broad spectrum of patients with axSpA, including patients not identifiable with diagnosis codes. The study objective was to estimate the performance of axSpA identification methods in the general Veterans Affairs (VA) population.

METHODS

A patient sample with known axSpA status (n = 300) was established with chart review. For feasibility, this sample was enriched with veterans with axSpA risk factors. Algorithm performance outcomes included sensitivities, positive predictive values (PPV), and F1 scores (an overall performance metric combining sensitivity and PPV). Performance was estimated with unweighted outcomes for the axSpA-enriched sample and inverse probability weighted (IPW) outcomes for the general VA population. These outcomes were also assessed for traditional identification methods using diagnosis codes for the ankylosing spondylitis (AS) subtype of axSpA.

RESULTS

The mean age was 54.7 and 92% were male. Unweighted F1 scores (0.59-0.74) were higher than IPW F1 scores (0.48-0.65). The full algorithm had the best overall performance (F1_IPW 0.65). The Early Algorithm was the most inclusive (sensitivity_IPW 0.90, PPV_IPW 0.38). The traditional method using ≥ 2 AS diagnosis codes from rheumatology had the highest PPV (PPV_IPW 0.84, sensitivity_IPW 0.34).

CONCLUSION

The axSpA identification methods demonstrated a range of performance attributes in the general VA population that may be appropriate for various types of studies. The novel identification algorithms may expand the scope of research by enabling identification of more diverse axSpA populations.

Identification of Axial Spondyloarthritis Patients in a Large Dataset: The Development and Validation of Novel Methods

OBJECTIVE

Observational axial spondyloarthritis (axSpA) research in large datasets has been limited by a lack of adequate methods for identifying patients with axSpA, because there are no billing codes in the United States for most subtypes of axSpA. The objective of this study was to develop methods to accurately identify patients with axSpA in a large dataset.

METHODS

The study population included 600 chart-reviewed veterans, with and without axSpA, in the Veterans Health Administration between January 1, 2005, and June 30, 2015. AxSpA identification algorithms were developed with variables anticipated by clinical experts to be predictive of an axSpA diagnosis [demographics, billing codes, healthcare use, medications, laboratory results, and natural language processing (NLP) for key SpA features]. Random Forest and 5-fold cross validation were used for algorithm development and testing in the training subset (n = 451). The algorithms were additionally tested in an independent testing subset (n = 149).

RESULTS

Three algorithms were developed: Full algorithm, High Feasibility algorithm, and Spond NLP algorithm. In the testing subset, the areas under the curve with the receiver-operating characteristic analysis were 0.96, 0.94, and 0.86, for the Full algorithm, High Feasibility algorithm, and Spond NLP algorithm, respectively. Algorithm sensitivities ranged from 85.0% to 95.0%, specificities from 78.0% to 93.6%, and accuracies from 82.6% to 91.3%.

CONCLUSION

Novel axSpA identification algorithms performed well in classifying patients with axSpA. These algorithms offer a range of performance and feasibility attributes that may be appropriate for a broad array of axSpA studies. Additional research is required to validate the algorithms in other cohorts.

US National Health and Nutrition Examination Survey Arthritis Initiatives, Methodologies and Data

The US National Health and Nutrition Examination Survey (NHANES) has collected population-based, nationally representative examination, laboratory, and radiographic data for arthritis and musculoskeletal diseases for more than 50 years. The resulting body of data and publications are substantial, yet much data remain unpublished. This review provides a basic understanding of the design and capabilities of the NHANES survey, reviewing the major accomplishments in the area of arthritis and musculoskeletal diseases. Currently available US National Health and Nutrition Examination Survey arthritis-related datasets are identified. Guidelines for using these data, and opportunities for data analysis and designing future studies are presented.