[Long-term administration of cyclosporine A in patients with IgA nephropathy].

BACKGROUND

IgA nephropathy is the most common glomerulonephritis all over the world and a considerable proportion of the patients reaches end-stage renal failure. Yet the standard treatment for the patients with progressive course and/or great proteinuria is currently lacking. All suggested treatment protocols, including short-term treatment with cyclosporine A had equivocal results. Therefore we decided to try long-term cyclosporine treatment.

METHODS AND RESULTS

We treated 6 patients (4 males, 2 females, age 21-31 years) with bioptically proven IgA nephropathy and proteinuria over 3.5 g/24 hrs with or without nephrotic syndrome non responding to corticosteroid therapy administered for at least 3 months. Patients with serum creatinine greater than 200 mumol/l and/or glomerulosclerosis in more than 50% of glomeruli in renal biopsy were excluded. Pts were given cyclosporine A in initial dose 5 mg/kg bw/day then titrated aiming to the serum concentration of 70-150 ng/ml. Prednisone 5-10 mg on alternate days was given with cyclosporine. Proteinuria decreased during first month of therapy from 4.66 +/- 0.43 g/day to 1.38 +/- 0.29 g/day (p < 0.01) and remained low after one year of treatment (0.59 +/- 0.14 g/day, p < 0.001). Glomerular filtration rate (creatinine clearance) did not change during first month of therapy (1.25 +/- 0.21 ml/s vs. 1.38 +/- 0.29 ml/s), but slightly decreased after one year of treatment (1.05 +/- 0.14 ml/s, p < 0.05). We also calculated ratio of proteinuria to glomerular filtration rate (g/l) to assess the role of hemodynamic changes in the decrease of proteinuria. This ratio was 53.80.10(-3) +/- 15.20.10(-3) before cyclosporin therapy, it decreased significantly after one month (11.56.10(-3) +/- 3.24.10(-3), p < 0.05) and achieved the lowest value after one year of therapy (6.78.10(-3) +/- 4.25 .10(-3) +/- 4.25.10(-3), p < 0.01). Serum cholesterol also significantly decreased after 12 months of therapy (6.21 +/- 0.62 vs. 5.41 +/- 0.45 mmol/l, p < 0.05).

CONCLUSIONS

CyA significantly lowered moderate to high proteinuria with much less decrease of glomerular filtration rate in 6 patients with IgA. Significant decrease of proteinuria/GFR ratio strongly suggests some non-hemodynamic mechanisms of cyclosporine action in these patients. Therapy was well tolerated and side-effects were not so severe to require cyclosporine withdrawal.