Researchers Identify Association Between Lupus Nephritis and Low Bone Mineral Density

Low bone density is associated with lupus nephritis (LN)—independent of steroid treatment and other clinical manifestations—among persons with juvenile-onset systemic lupus erythematosus (SLE), according to findings from a retrospective study presented at the Paediatric and Adolescent Rheumatology Conference. The findings suggest that low bone mineral density (BMD) may be a potential predictor biomarker for LN.

For the study, the researchers reviewed data of 134 persons with juvenile-onset SLE who were seen at young adult and adolescent clinics after transitioning from pediatric services.

Of the participants, 112 (83.6%) were female and 45 (33.6%) had LN. The median age was 22 years (interquartile range [IQR], 20-24 years). 

The researchers used Mann-Whitney U or χ2 tests to compare the characteristics between persons with juvenile-onset SLE with and without LN. Additionally, univariate and multivariate analyses were performed to identify potential predictors of LN.

The median disease duration was 10 years (IQR, 8-14 years) among persons with juvenile-onset SLE with LN compared with 8 years (IQR, 6-13 years) among persons with juvenile-onset SLE without LN. The highest levels of double-stranded DNA were observed among persons with LN (P = .022).

Results showed no differences in the overall clinical manifestations and complications between persons with juvenile-onset SLE with or without LN, with the exception of prevalence of low BMD.

Among persons with juvenile-onset SLE with LN, 16 (35.5%) had low BMD compared with 11 (12.4%) without LN (P = .008).

Findings from the univariate logistic regression analysis indicated that the use of mycophenolate mofetil (P = .021) and the presence of LN (P = .007) were associated with low BMD. Findings from the multivariate analysis also showed that LN was associated with low BMD (P = .008).

The researchers observed that persons with juvenile-onset SLE with LN had received more aggressive treatment, including the use of cyclophosphamide, mycophenolate mofetil, and rituximab. However, there was no difference regarding the duration of steroid treatment.

“Low bone mineral density in patients with [juvenile] SLE is well described. However, this is the first study highlighting the association of low bone density with LN independent of total duration of steroid treatment or other clinical manifestations,” the researchers concluded.

—Melinda Stevens

Reference:

Madenidou A-V, Mahfouz Y, Chang O, El-Sharnouby F, Foley C, Ciurtin C. Low bone mineral density was associated with lupus nephritis irrespective of duration on steroid treatment in a large observational study of juvenile systemic lupus erythematosus patients [abstract P34]. Rheumatology. 2019;58(suppl 4):kez416.001. https://academic.oup.com/rheumatology/article/58/Supplement_4/kez416.001/5575874. Accessed October 3, 2019.