Recurrent lupus nephritis in renal transplant recipients revisited: It is not rare.

Background. Although recurrent lupus nephritis (RLN) after kidney transplantation is reported to be rare (1%-4%), recent studies suggest a higher incidence. The purpose of this study was to determine the incidence of RLN in a large cohort of renal transplant recipients with systemic lupus erythematosus (SLE). Methods. The records of 54 renal transplant recipients with SLE were reviewed. Thirty-one patients underwent biopsy because of worsening renal function and proteinuria. All biopsy specimens were evaluated by light microscopy, immunofluorescence (IF), and electron microscopy (EM). Results. Among the 50 patients with at least 3 months of follow-up, RLN was present in 15 (52% of patients who underwent biopsy, 30% of total patients): mesangial lupus nephritis (LN) (class II) in eight, focal proliferative LN (class III) in four, and membranous LN (class Vb) in three patients. One patient had graft loss because of RLN (class II) at 10.5 years. The duration of dialysis before transplantation was not different between patients with RLN compared to patients without RLN (P=0.40). Overall patient survival (n=50) was 96% at 1 year and 82% at 5 years, and graft survival was 87% at 1 year and 60% at 5 years. Graft survival was worse in patients who underwent biopsy compared with patients who never underwent biopsy (P < 0.01). Conclusions. RLN is more common than previously reported, but in our series, graft loss because of RLN was rare. Aggressive use of allograft biopsies and morphologic evaluation with IF and EM are important factors in the diagnosis of RLN. The impact of new immunosuppressive agents on the incidence of RLN remains to be seen.