Article Text
Abstract
Background There are limited population-based data on morality in juvenile Systemic Lupus Erythematosus (SLE). Here, we examine standard mortality rate (SMR) in juvenile SLE and compare with young- and adult-onset subsets in a large population-based SLE cohort.
Methods The population-based cohort included all SLE patients who were resident in Southeast Norway 1999 – 2017, had SLE diagnosis confirmed by chart-review and met the 1997 ACR criteria for SLE. Cases with new-onset disease 1999–2017 were defined as inception cases. We stratified the cohort by age at diagnosis, with juvenile SLE diagnosed age <16, young-onset age 16–29 and adult-onset age ≥30. Lupus nephritis (LN) was defined by 1997 ACR criteria for SLE. We compared ratios with X2-test, estimated risk of death by SMR using 15 controls per SLE case (individually matched to case by age, sex and ethnicity) and survival in juvenile inception cases by Kaplan-Meier.
Results The cohort included 1300 SLE cases; of whom 93 (7%) were diagnosed at age<16, 461 (35%) at age 16–29 and 746 (57%) at age≥30 (table 1). Juvenile SLE developed significantly more LN than those with later disease-onset (table 1). None of the juvenile inception cases died during follow-up and 10-year survival was 100% (99% in matched-controls).
The SMR was significantly higher in juvenile and young adult-onset than in adult-onset, with highest SMR in juvenile-onset (table 1). SMR in men and women with juvenile-onset was 6.3 (95% CI 0.6–38) and 7.4 (95% CI 3.4–16), respectively. In juvenile SLE, presence of LN increased SMR to 9.2 (95% CI 3.6–22). Correspondingly, in non-LN juvenile patients SMR was 4.3 (95% CI 0.8–16).
Conclusions Early disease-onset greatly increase SMR in SLE to a maximum of 7.2 in juvenile-onset, twice as high as in juvenile type-1 Diabetes.1 We find no sex-specific differences in SMR, but juvenile-onset with LN has the highest SMR.
References
Gagnum V, Stene LC, Sandvik L, Fagerland MW, Njølstad PR, Joner G, et al. All-cause mortality in a nationwide cohort of childhood-onset diabetes in Norway 1973–2013. Diabetologia. 2015;58(8):1779–86.
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