Clinical and pathological features of biopsy proven lupus nephritis with renal asymptomatic patients

    WU Zhenª² Biao, ZHU Ping, LENG Nan, JIA Yun, LIU Ling, ZHANG Huiª²Qin

    Department of Clinical Immunology, Xijing Hospital, Fourth Military Medical University, Xi¬ðan 710033, China

    ¡¾Abstract¡¿ AIM: To investigate the clinical and pathological features of biopsy proven lupus nephritis in systemic lupus erythematosus (SLE) patients without renal symptoms. METHODS: Fortyª²five biopsied SLE patients with asymptomatic biopsy proven lupus nephritis but without renal symptoms (without urinary sediment, quantitative proteinuria < 0.5 g/24 h, with normal creatinine clearance) were investigated and compared with 50 patients with overt lupus nephropathy (with abnormal urinary sediment, 24 h quantitative proteinuria and creatinine clearance). Antinuclear antibodies (ANA), antiª²ENA antibodies, complement C3, C4, circulating immune complexes (CIC), antiª²dsDNA antibodies, clinical disease activity index (SLEDAI) and renal biopsies were evaluated in all the patients. RESULTS: Forty out of the 45 patients (89%) had lupus nephritis according to histopathological findings. WHO class II was the predominant renal lesion in the group with asymptomatic biopsy proven lupus nephritis (P<0.01), whereas class IV was in the lupus nephritis (LN) group with overt renal symptoms (P<0.01). The prevalence of ANA, antiª²Sm and antiª²RNP antibodies, and C4 serum levels showed no statistical differences between the two groups (P>0.05). On the contrary, in the overt symptom LN group, the prevalence of antiª²dsDNA antibodies, elevated CIC and diminished C3 serum levels and higher clinical activity index (SLEDAI) were significantly different with that in asymptomatic LN group (P<0.01). Organs involved in the two groups were quite different. The major organs, such as blood system, lungs, kidney, heart, central nerves system in the asymptomatic LN group were less likely to be damaged compared with those in the overt LN group. CONCLUSION: Lupus nephritis is highly prevalent in renal asymptomatic SLE patients and WHO class II is the predominant type. Renal injury is associated with abnormal levels of CIC, C3, antiª²dsDNA antibody and clinical activity index (SLEDAI). ......