Consult Rounds: Repeat biopsy in lupus nephritis

Two questions:
1. What is the value of repeat biopsy in Lupus Nephritis? You have a Class III on biopsy A and improvement following treatment; 7 months later similar presentation: would you re biopsy or consider Class III and treat accordingly? 

One retrospective trial in NDT in 2012 had looked at this. Twenty-five patients had one repeat biopsy, 6 patients had two and 4 patients had three repeat biopsies. Forty-nine comparisons between reference and repeat biopsies could be made. In 25 cases (54.3%), there was no shift in ISN/RPS class on repeat biopsies. In 41 instances, paired biopsies showed proliferative lesions both on reference and repeat biopsies, whereas five of six cases with non-proliferative lesions on a reference biopsy switched to
proliferative lesions on a repeat biopsy. Clinically significant class switches during lupus nephritis flares were more frequent in patients with non-proliferative lesions in their reference biopsy. The authors conclude that the repeat bx was most necessary when the index biopsy was non proliferative. With lupus nephritis, the main rule to remember is that " lupus nephritis follows no rule". It appears that many instances, class switches are common and a repeat biopsy might add value re class switches. The other factor that most studies don't discuss is that the repeat biopsies can offer a choice of "not treating" as there might be substantial scarring and make a more informed decision regarding tough immunosuppresive agents.

2. After induction, is a repeat biopsy needed?

Another NDT paper in 2012 looked at this question. 77 patients followed up for a median duration of 8.7 years.  One-third of the patients with partial remission and 14% of patients with non remission had no histological evidence of active disease on second biopsy. At the second biopsy, but not at the baseline biopsy, activity index was predictive of survival. The 10-year renal survival rate was
100% for those with an activity index of 0, 80% for those with an activity index of 1 or 2 on the second biopsy and 44% for those with an index of >2, regardless of remission status. The authors conclude that a second kidney biopsy at the end of maintenance phase of therapy is an important diagnostic and prognostic tool that could guide physicians to safer practices with better outcomes. Interestingly, patients we would think were not in remission had no histological evidence of active disease on second biopsy- which would allow us to consider stopping treatment in some cases. This an observational retrospective trial with limitations and it would be interesting to see what experiences of others holds on this notion of repeat biopsy after induction?

Per UptoDate.com, the indications for repeat biopsy are:
1 Increasing proteinuria
2. Active sediment with rising crt
3. Rising crt
4. Unrelated to SLE as the cause of renal disease ( other GNs and drug induced diseases)