Difference between renal failure associated with methylprednisolone pulse therapy and deterioration of renal function unrelated to methylprednisolone therapy.

In this study, we attempted to analyze the differences between renal failure associated with methylprednisolone (MP) pulse therapy and natural deterioration of renal function that was unrelated to MP administration. Of 80 patients with renal or collagen disease who received MP pulse therapy at our hospitals, 13 were selected for the study whose serum creatinine levels increased more than 0.5 mg/dl from baseline values following therapy. Somewhat arbitrarily, 7 patients were placed in an MP-associated renal deterioration group (group 1) in which serum creatinine levels returned naturally, or following induced diuresis, to baseline levels, and 6 patients in an MP-independent natural deterioration group (group 2) in which renal function progressively deteriorated. Renal function similarly deteriorated in the two groups following pulse therapy, irrespective of the degree of crescent formation. Our data suggested that hypoproteinemia is the most important index for differentiating MP-associated renal failure from natural deterioration of renal function unrelated to MP pulse therapy. In patients that are nephrotic and have impaired renal function, worsening of renal function following pulse therapy may partly be due to transient MP-associated renal failure. On the other hand, in patients without hypoproteinemia, worsening of renal function is most likely due to active primary disease and is probably not associated with MP pulse therapy.