Effects of long-term aurothiomalate and D-penicillamine treatments on renal function and urinary excretion of prostanoids in patients with rheumatoid arthritis

The effects of long-term aurothiomalate and D-penicillamine treatments on renal function and the urinary excretion of prostanoids were studied in 20 patients with classic or definite rheumatoid arthritis. Twelve-hour urine was collected overnight, on the following day blood samples were taken in the morning and 12-hour urine was collected during the following day. Albumin excretion into the urine was determined by a sensitive quantitative method. Beta-2-microglobulin (B2MIGLO) and N-acetyl-beta-glucosaminidase (NAG) serum concentrations and excretions into the urine were measured to detect possible tubular or glomerular damage, respectively. The excretions of prostaglandin E2 (PGE2), thromboxane B2 and 6-keto-PGF1 alpha into urine were determined. In the aurothiomalate group, albumin excretion ranged 1-16 mg/12 h, and in the penicillamine group 0.8-31 mg/12 h. In the penicillamine group, but not in the aurothiomalate group, total protein, B2MIGLO and PGE2 excretions were higher (p less than 0.05) during the daytime than during the night. The daytime excretion of PGE2 was higher (p less than 0.01) in the penicillamine than in the aurothiomalate group. In the penicillamine group B2MIGLO excretion into urine correlated (p less than 0.01) with PGE2 excretion in the daytime. According to the results, not even long-term aurothiomalate treatment affects renal prostanoid excretion, while penicillamine increases urinary PGE2 excretion. This could be related either to the cofactor-like activity of penicillamine in the prostanoid synthesis or to damage in tubular cells. The role of prostanoids in maintaining blood flow and filtration may be more important in patients with renal damage than in normal conditions.