Clinical presentation of lupus nephritis becoming less severe over time
The clinical patterns and renal outcomes in patients with lupus nephritis (LN) – a severe manifestation of systemic lupus erythematosus (SLE) – have become less severe over the last 5 decades, translating to better long-term renal survival, according to a study.
“[T]he clinical presentation at the time of kidney biopsy for suspected LN … is now characterized by an increase in isolated urinary abnormalities and a decrease in renal insufficiency,” said the researchers.
These were found after evaluating 499 individuals (85.6 percent women) diagnosed with LN from 1970 to 2016, who were grouped into three according to the year of LN diagnosis: 1970–1985 (period 1; n=106), 1986–2001 (period 2; n=158), and 2002–2016 (period 3; n=235). [Ann Rheum Dis 2018;77:1318-1325]
Apart from the significant increase in the prevalence of isolated urinary abnormalities from period 1 to 3 (from 28 to 115; p<0.001), there were decreases in renal insufficiency (from 15 to 8; p<0.0001), mean values of serum creatinine (from 1.8 to 1.0 mg/dL; p<0.0001), and frequency of acute nephritic syndrome (from 31 to 29; p=0.0001) throughout the 46-year follow-up period.
“The [progressively milder] clinical presentation is consistent with the progressive decline in serum creatinine at the time of LN diagnosis, which is one of the most important predictors of renal adverse outcomes in short- and long-term follow-ups,” said the researchers.
The follow-up period also saw a progressive increase in mean patient age at the time of LN diagnosis from period 1 to 3 (from 28.4 to 34.4 years; p=0.001) and a longer lag time between SLE onset and LN occurrence (1.3 to 4.6 years; p<0.0001).
“These changes may result from an earlier diagnosis of SLE, which leads to a closer surveillance of LN over time and, in turn, allows the identification of mild disease phenotypes, as well as from the earlier and more appropriate therapeutic intervention that includes the extensive use of antimalarial drugs, [mycophenolate mofetil], and biological drugs capable of hindering the development of LN,” said the researchers.
Despite the lack of differences in terms of histological classes throughout the three periods, there was a substantial increase in mixed forms (class III + IV and IV + V) from the first to third period (4.7 percent to 17.4 percent; p=0.006), which was associated with poor prognosis. [J Am Soc Nephrol 1996;7:299-305]
Although consistent throughout periods 1, 2, and 3, the activity index was considered high (6.2, 6.6, and 5.9, respectively) which, together with the isolated urinary abnormalities plus the increased class III and IV cases, underline the importance of renal biopsy in defining the prognosis and tailoring therapeutic approaches to LN, the researchers pointed out. “Due to the decreasing trend of LN presentation with severe renal dysfunction, these histopathological variables remain a valuable tool to aid the physician in defining prognosis and taking treatment decisions in all patients.”
“The progressive improvement in renal survival in our cohort is the result of a comprehensive approach, which includes a prompt diagnosis of renal involvement, a wider indication to renal biopsy, treatment based on renal biopsy, and increased clinical experience in the management of LN,” they concluded, recommending further trials given the highly Caucasian population and retrospective nature of the study which could have limited the findings.