The Clinicopathologic Characteristics of Recurrent Lupus Nephritis Post-Transplant Using Surveillance and Indication Biopsies.

Introduction: The incidence of recurrent lupus nephritis (RLN) after kidney transplantation (KTx) varies with higher rates of RLN reported in surveillance biopsy-based studies (vs. clinically indicated biopsies).

Methods: We present a multisite retrospective study evaluating surveillance and clinically indicated biopsies in 209 first KTx recipients who had native lupus disease.

Results: Of the 112 patients with satisfactory material for comprehensive histology, RLN was observed in 40 (35.7%). We describe the pathology of histologic RLN (HRLN; 40%) and clinical RLN (CRLN; 60%). African Americans had the highest recurrence rate (48.3%) of whom 50% had CRLN. HRLN was noted as early as 18 days, with early diagnosis (< 3 months of follow-up time) using surveillance biopsies. Mesangioproliferative pattern of glomerular injury ( class II lupus nephritis [LN] by International Society of Nephrology/Renal Pathology Society) was the most frequent pattern of RLN. IgG dominance or codominance was the most frequent Ig staining pattern. A full-house pattern of staining was only seen in 6% of HRLN and 37% of CRLN. C4d stain, as a stand-alone immunofluorescence (IF) test, was performed in the index renal allograft biopsy in 37.5% of patients, with RLN, prompting evaluation with a full IF panel. Electron microscopy (EM) confirmed the findings on IF. Graft loss because of lupus-associated pathology was observed in 50% of RLN subjects, of which thrombotic microangiopathy was seen in 25%.

Conclusion: Our study demonstrates that RLN is frequent and may be clinically quiescent. Sequential biopsy evaluation provided an opportunity to study the natural evolution of the disease.