Changes in macrophage infiltration and podocyte injury in lupus nephritis patients with repeated renal biopsy: Report of three cases

BACKGROUND In this study,we retrospectively analysed macrophage infiltration and podocyte injury in three patients with diffuse proliferative lupus nephritis(LN)who un-derwent repeated renal biopsy.CASE SUMMARY Clinical data of three diffuse proliferative LN patients with different pathological characteristics(case 1 was LN IV-G(A),case 2 was LN IV-G(A)+V,and case 3 was LN IV-G(A)+thrombotic microangiopathy)were reviewed.All patients underwent repeated renal biopsies 6 mo later,and renal biopsy specimens were studied.Macrophage infiltration was assessed by CD68 expression detected by immunohistochemical staining,and an immunofluorescence assay was used to detect podocin expression to assess podocyte damage.After treatment,Case 1 changed to LN III-(A),Case 2 remained as type V LN lesions,and Case 3,which changed to LN IV-S(A),had the worst prognosis.We observed reduced macro-phage infiltration after therapy.However,two of the patients with active lesions after treatment still showed macrophage infiltration in the renal interstitium.Before treatment,the three patients showed discontinuous expression of podocin.Notably,the integrity of podocin was restored after treatment in Case 1.CONCLUSION It may be possible to reverse podocyte damage and decrease the infiltrating ma-crophages in LN patients through effective treatment.

Changes in pathological pattern and treatment regimens based on repeat renal biopsy in lupus nephritis

Background Relapses occur frequently in patients with lupus nephritis. Renal biopsy is the gold standard for assessing renal activity and hence guiding the treatment. Whether repeat renal biopsy is helpful during flares of lupus nephritis remains inconclusive. In the present study, we retrospectively reviewed the patients with lupus nephritis who had more than one renal biopsy with the hope to find the clinical value of repeat biopsy. Methods Patients who had a diagnosis of lupus nephritis and two or more renal biopsies were selected from the database of the patient pathology registration at this renal division. Renal biopsy was evaluated according to the International Society of Nephrology/Renal Pathology Society （ISN/RPS） classification of lupus nephritis. The pathological patterns and treatment regimens were analyzed after a repeat biopsy. Results We identified 44 systemic lupus erythematosus patients with serial renal biopsies. In total, there were 94 renal biopsies. Overall, the pathological transition occurred in 64% instances according to the ISN/RPS class. When the transition was analyzed according to proliferative, membranous or mix lesions, it showed different profile： 35% in patients with proliferative lesion, 23.5% patients with mix lesions, 100% in patients with pure membranous lesion. The pathological transition could not be predicted by any clinical characteristics. After the repeat renal biopsy, 34% of patients had a change in their treatment regimens. Conclusions The pathological conversion was very prevalent in patients with lupus nephritis. However, the transitions became less prevalent when they were analyzed according to pure membranous, proliferative, and mix lesion. Repeat biopsy miht be helpful to avoid unnecessary increased immunosuppression theraDv.