Analysis Of The Clinicopathological And Immunological Features In IgA Nephropathy

OBJECTIVE: To investigate the role of immunologic reaction and complement system in the pathogenesis and progression of IgA nephropathy(IgAN), to study the clinical and pathological factors predicting the progression of IgA nephropathy.METHORDS:1. Cases: We selected 63 IgAN patients with complete serum IgA and C3 data who have been histologically diagnosed by renal biopsy during the year of 1999 to 2005, excluding the cases of Henoch-Schoenlein purpura, thin basement nephropathy, liver cirrhosis, systemic lupus erythematosus(SLE) or other systemic diseases. There were 37 non-IgAN patients in the control group, including minimal change nephropathy, focal segmental glomerulonerphritis, membranous nephropathy, mensangial proliferative glomerulonephritis, sclerosing glomerulonephritis. None of these patients were nephrotic syndrome or treated with corticosteroids, immunosuppessions during the previous 3 months of renal biopsy, and all of their creatinine were lower than 133μmol/L.2. Clinical data: All these clinical data including sex, onset age, blood pressure, 24 hours urine protein etc. were obtained from the hospital case history.3. Serum immunologic test: All these serum samples were tested IgA and C3 using the method of transmission immunoturbidimetry. In our hospital, the normal ranges are 0.65～3.00g/L and 0.8～1.4g/L respectively.4. Pathological test: All the biopsy specimens of IgAN patients were stained with hematoxylin-esion, IgA and C3 immunofluorescence. The result of immunofluorescence test was graded as — ～ + + + + according to the fluorescence intensity under the fluoroscope; histologic presentation under the light microscope were devided into 5 groups acording to the Lee's histological classification of IgAN. In addition, we assign scores to tubulointerstitial lesions: interstitial fibrosis, tubularatrophy, tubular swelling, interstitial cellular infiltration.5. Statistical analysis: Using SPSS 10.0, all the continous variable data were compared between two groups by t-test, the relationship between categorical variables were tested using Kendall's rank correlation coefficient.RESULTS: 1. Serum IgA in IgAN group was significantly higher than in non-IgAN. 2. Serum C3 in the group with higher IgA immunofluorescence intensity was significantly lower than in the lower group. Serum C3 in the group with higher C3 immunofluorescence intensity was significantly lower than in the lower group, too. 3. The IgA and C3 immunofluorescence intensity grades were significantly rank correlated using non-parametric correlation analysis. 4. Serum IgA and age in the group with severe histological change was significantly higher than in the group with relatively moderate histological change. 5. Score of tubulointerstitial lesions was significantly rank correlated with that of glomerular lesions. 6. High blood pressure was significantly rank correlated with the histological classification. CONCLUSIONS: 1. IgAN is considered as an immune-mediated glomerulonephritis, the immune system may play an important role in the pathogenesis and progression of it. The rise of serum IgA and decrease of serum C3 maybe very important for it. 2. Old age and hypertention are risk factors of IgAN. 3. Tubulointerstitial lesions may suggest the prognosis.