Text Box: MESANGIPROLIFERATIVE GLOMERULONEPHYITIS WITH MANIFESTATION OF PRIMARY NEPHRITC SYNDROME Lin Y, Zhong RR, Cai ZQ, Cheng JY, Wang T Fujian Provincial Hospital, Fuzhou, China Objective: To study the treatment and prognosis of mesangiproliferative glomerulonephyitis (MsPGN) with manifestation of primary nephritic syndrome (PNS). Methods: 106 PNS were classified into simple and nephritic groups by clinic manifestation, and also into simple MsPGN and non- simple MsPGN groups (with focal segmental glomerulosclerosis and / or renal interstitial damage) by histopathology. All this cases had 8 weeks of initial treatment with prednisone. Those cases that cannot attain remission after the 8- week- therapy, or depend on cortisone, or relapse frequently, were treated with pulse cytoxan. Results: 72 of all attain remission after the 8-week-therapy, 67 were simple group, and 5 were nephritic group. This difference was not significant between these two groups. 62 of 75 simple MsPGN attain remission after the 8-week-therapy, but only 10 of 31 in non-simple MsPGN. This difference was high significant between two groups (x2=25.6 p<0.01). 3 cases died of severe infections, they all were non-simple MsPGN, but with manifestation of PNS. One died of chicken pox; the other two were secondary infection by malignant lymphoma and nodose panniculitis respectively. Conclusion: Clinical classification has its limitations. The response to the 8-week-therapy of prednisone cannot be used to estimate the hisopathologic diagnosis and prognosis. Early renal biopsies play an important role in guidance of treatment. Severe infection was direct cause of death. 1005