Mesangial lupus nephritis in Chinese is associated with a high rate of transformation to higher grade nephritis.

Mesangial lupus nephritis was thought to be a mild form of lupus nephritis. However, case reports suggest that this type of nephritis could be associated with a high rate of transformation to more serious classes. We retrospectively reviewed the clinical features, clinical response at one year following treatment, as well as the long-term outcome of patients with mesangial lupus nephritis identified on their first renal biopsy. The possible clinical parameters that may predict poor outcome were examined. Nineteen patients with a median duration of follow-up of 9.6 (2.5-11.4) years were identified. At one year after biopsy, eight patients achieved complete remission, two patients achieved partial remission and nine patients had no response. Of the 10 responders, four relapsed after a median duration of 53 (42-97) months. Nine out of 10 patients (six nonresponders and four responders who relapsed) who underwent a second biopsy showed transformation to a higher grade nephritis. The long-term outcome remained favourable in nine patients. Responders and patients who were given angiotensin-converting enzyme inhibitors were associated with favourable long-term outcome. Our data highlight that renal biopsy should be repeated early in Chinese patients with mesangial nephritis who failed to respond to treatment in order to identify those who may require intense immunosuppressive therapy.