Clinical comparisons between previously diagnosed SLE and newly diagnosed SLE by kidney biopsy

BACKGROUND: Lupus nephritis is a type of major organ involvement in systemic lupus erythematosus (SLE) patients that leads to higher rates of morbidity and mortality and may present initially in 28% of SLE patients. However, there are limited data available on clinical differences or predictors for biopsy-proven lupus nephritis in established versus newly diagnosed SLE cases. METHODS: Adult patients undergoing kidney biopsy for the first time with a diagnosis of lupus nephritis were eligible for inclusion. Patients were categorized into two groups: those with previously diagnosed SLE and those with newly diagnosed SLE by kidney biopsy. Factors associated with newly diagnosed SLE were determined using logistic regression analysis. RESULTS: There were 68 patients diagnosed with lupus nephritis by kidney biopsy. Of those, 31 cases (45.58%) were newly diagnosed. The newly diagnosed SLE group was significantly older (36.87 vs 30.95 years) and had a lower proportion of females (74.19% vs 91.89%) than the previously diagnosed group. A new-onset hypertension was the only factor independently associated with newly diagnosed SLE by kidney biopsy. The adjusted odds ratio (95% CI) was 5.152 (1.046, 25.363). CONCLUSIONS: Nearly half of the biopsy-proven lupus nephritis cases in this study were patients with newly diagnosed SLE. Patients with previously diagnosed SLE and newly diagnosed SLE by kidney biopsy had clinical differences.