CAN IMMUNOSUPPRESSIVE DRUGS SLOW THE PROGRESSION OF IGA NEPHROPATHY

The role of immunosuppressive drugs in the treatment of IgA nephropath y (IgAN) remains controversial. The effect of treatment with prednisol one and azathioprine on the clinical course of patients with IgA nephr opathy is described in this retrospective study. One hundred and fourt een patients, 66 treated (age 13-77 years) and 48 untreated (age 15-64 years), were evaluated. The two groups of patients differed significa ntly 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 h istopathological involvement in the treated group (P<0.01). Oral predn isolone 40 mg/day and azathioprine 2 mg/kg BW/day was commenced initia lly and after gradual tapering was continued at low dose (5 mg/day) fo r 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 defin ed as progressive or non-progressive on the basis of serial serum crea tinine (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% patie nts of the treated group (n=39), while only in 36% of the untreated gr oup (n=22), the difference was statistically significant (P < 0.001). Slopes of reciprocal of S-cr versus time were also calculated by linea r regression analysis to represent the trend of renal function for pat ients who had had 3 or more years follow-up (n=101). An analysis of va riance of these trends in patients with renal impairment at presentati on (n = 51) showed significant recovery of renal function in the treat ed group (n = 33) and a decline of renal function in the untreated gro up (n=18, P=0.004). There was no significant effect of the treatment o n proteinuria. The histopathological features that favoured response t o the treatment were mesangial proliferation, capsular adhesions and i nterstitial infiltration on light-microscopy, C3 and fibrin deposits o n immunofluorescence (P < 0.05). Sideeffects of treatment were observe d in 10 patients (15%) and treatment was discontinued in two patients with serious side-effects. Twenty-seven treated patients underwent rep eat biopsy after a median period of 13 months (range 6-48). As compare d to the first biopsy, most histopathological features on the second b iopsy remained stable in patients with non-progressive course whereas deterioration was noted in patients with progressive course. In conclu sion treatment with prednisolone and azathioprine appears to be benefi cial in slowing the progression of IgAN in patients with renal impairm ent and severe histopathological involvement at presentation.