CAN IMMUNOSUPPRESSIVE DRUGS SLOW THE PROGRESSION OF IGA NEPHROPATHY

The role of immunosuppressive drugs in the treatment of IgA nephropathy (IgAN) remains controversial. The effect of treatment with prednisolone and azathioprine on the clinical course of patients with IgA nephropathy is described in this retrospective study. One hundred and fourteen patients, 66 treated (age 13-77 years) and 48 untreated (age 15-64 years), were evaluated. The two groups of patients differed significantly with respect to heavier proteinuria (median 3.6 g/day, range 0.2-18 g/day), lower serum albumin level (<40 g/l) and more severe renal histopathological involvement in the treated group (P<0.01). Oral prednisolone 40 mg/day and azathioprine 2 mg/kg BW/day was commenced initially and after gradual tapering was continued at low dose (5 mg/day) for a median duration of 24 months (range 12-98). The median duration of follow-up was 46 months (range 12-180). The clinical course was defined as progressive or non-progressive on the basis of serial serum creatinine (S-cr). Of the patients who presented with renal impairment (S-cr>110 mu mol/l), a non-progressive course was observed in 79.5% patients of the treated group (n=39), while only in 36% of the untreated group (n=22), the difference was statistically significant (P < 0.001). Slopes of reciprocal of S-cr versus time were also calculated by linear regression analysis to represent the trend of renal function for patients who had had 3 or more years follow-up (n=101). An analysis of variance of these trends in patients with renal impairment at presentation (n = 51) showed significant recovery of renal function in the treated group (n = 33) and a decline of renal function in the untreated group (n=18, P=0.004). There was no significant effect of the treatment on proteinuria. The histopathological features that favoured response to the treatment were mesangial proliferation, capsular adhesions and interstitial infiltration on light-microscopy, C3 and fibrin deposits on immunofluorescence (P < 0.05). Sideeffects of treatment were observed in 10 patients (15%) and treatment was discontinued in two patients with serious side-effects. Twenty-seven treated patients underwent repeat biopsy after a median period of 13 months (range 6-48). As compared to the first biopsy, most histopathological features on the second biopsy remained stable in patients with non-progressive course whereas deterioration was noted in patients with progressive course. In conclusion treatment with prednisolone and azathioprine appears to be beneficial in slowing the progression of IgAN in patients with renal impairment and severe histopathological involvement at presentation.