'Refractory lupus nephritis' is a frequently used term but poorly defined. We conducted a survey among nephrologists and rheumatologists to spot the diversity of perceptions of this term and to better understand the clinical practice related to 'refractory lupus nephritis'. A total of 145 questionnaires completed by lupus nephritis experts were available for analysis, of which 52% were nephrologists, 34% rheumatologists, and 13% internists. Response to induction treatment was mostly assessed after six months (58%), but assessment at three months was more common with the use of the EURO lupus protocol than with other treatment protocols. Rheumatologists used urinary sediment to assess response more frequently than nephrologists (66 vs. 48%, p < 0.05, Chi2), while nephrologists conversely relied significantly more on clinical symptoms (61 vs. 31%, p < 0.0001, Chi2). Non-nephrologists quantified proteinuria preferentially by 24 h urine sampling, while the majority of nephrologists relied on the urinary protein/creatinine ratio (UPCR) or the albumin/creatinine ratio of spot urine samples (59 vs. 38%, p < 0.05, Chi2). A total of 91% were concerned about persistent immunological systemic lupus erythematosus activity. There was less concern about drug adherence, renal scarring, genetic factors or other kidney diseases. Less than 20% check for drug adherence by regularly monitoring drug plasma levels. Nephrologists considered a re-biopsy more often than rheumatologists (58 vs. 38%, p < 0.05, Chi2). Together, among lupus nephritis experts there is considerable diversity in the perception of what the term 'refractory lupus nephritis' describes and how it is defined. A consensus definition of 'refractory lupus nephritis' is needed.
Keywords: Immune complex; biopsy; disease activity; proteinuria; therapy.