The Clinical And Pathological Characteristics In Patients Of ClassⅡ Lupus Nephritis With Nephrotic Syndrome

Objective:To investigate the clinical and renal histolotical characteristics in patients of Class Ⅱ LN with nephrotic syndrome.Methodology:One hundred and twenty four patients [112females and12males, mean age29.2±11.4years, SLE disease duration0.25^360months (median11months), LN duration0.07-168months (median1.5months)] with Class Ⅱ LN, who were biopsy-proven and followed in our Nephrology Department, were divided into nephritic syndrome (NS) group (urine protein>3g/d and serum albumin<30g/L, n=27) and non-NS group (urine protein<3g/d and serum albumin≥30g/L, with or without hematuria, n=97). The degree of mesangial proliferation was graded into normal (M0)、mild (M1)、moderate (M2) and severe (M3). Diffuse foot process effacement was defined as more than50%of the glomerular capillary loops showing foot process effacement by EM. Clinical, immunological, pathological features and prognosis were compared between the two groups. Results:There were27cases (21.8%) in NS group and97cases (78.2%) in non-NS group. No significant differences in gender, onset age, LN duration and SLE duration were found between the two groups. Compared with non-NS group, the patients with NS group had a much higher incidence of renal manifestations as the first onset symptom (77.8%vs15.5%, P<0.01) and acute kidney injury (29.6%vs0, P<0.01), but much lower incidence of malar rash (40.7%vs69.1%, P<0.01), fever (14.8%vs62.9%, P<0.01), arthritis (29.6%vs75.3%, P<0.01), hematuria (0vs34%, P<0.01) and serum anti-dsDNA positivity (29.6%vs52.6%, P<0.05). In renal histology, the NS group had less severe mesangial proliferation (M2+M3:7.4%vs59.8%, P<0.01), but significantly higher incidence of diffuse foot process effacement (88.9%vs0, P<0.01) than that in non-NS group. Remission rate showed no difference between the two groups (100%vs98.4%, P>0.05), but the recurrence rate was much higher in NS proup than that in non-NS group (69.9%vs33.3%, P<0.01), and no patients progressed to end stage renal failure after the follow-up for8-125months (median55months) and6～274months (median57months) respectively. Repeated renal biopsy in7patients (2in NS group and5in non-NS group) after relapsing showed no histological transformation in the NS group, while all five patients in the non-NS group showed histological transformation (two to class Ⅲ, one to class Ⅳ, Ⅴ and Ⅳ+Ⅴ respectively).Conclusions:Our data demonstrated that the nephrotic class Ⅱ LN is a podocyte disease which should be defferentiated from the class II LN with mesangial proliferation. Further studies are needed to explore the pathogenesis of podocyte injury in SLE.