Clinical Characteristics and Treatment of Lupus Nephritis – Preliminary Analysis of Observational Data From a National Referral Centre

Lupus nephritis (LN) is one of the most severe features of systemic lupus erythematosus (SLE). Data on LN is scarce in the Croatian population. We analysed the characteristics of LN patients diagnosed at our tertiary referral centre. In this retrospective study, we analysed the following features of patients with biopsy-proven LN diagnosed between 2011 and 2020: demographics, renal laboratory parameters, renal histopathology, and treatment. A total of 38 patients were included (30 females; mean age 39±15 years). The most common indication for kidney biopsy was proteinuria (89%). The proportion of LN classes was: class I (2.6%), II (5.3%), III (18.4%), IV (42.1%), V (13.2%), III+V (10.5%), IV+V (5.3%). The median time from SLE diagnosis to histologic confirmation of LN was 1.0 year. All patients were treated with methylprednisolone (MP), 68% received MP pulses. Induction treatment included intravenous (IV) cyclophosphamide (CYC) (71%) (15 patients treated per Euro-Lupus and 9 per the National Institutes of Health regimen), oral CYC (3%), or mycophenolate mofetil (11%). 79% of patients received antimalarials. While there is heterogeneity between different populations, our patient profile was similar to that from other European studies. Further follow-up of this group is necessary to assess outcomes in our population.