Beta 2-microglobulin levels in patients with renal insufficiency.

beta 2-microglobulin (beta 2M) has been implicated in the pathogenesis of amyloidosis in long-term dialysis patients. beta 2M levels were measured in patients with chronic renal failure: before and after conventional hemodialysis in 30, before and after high-flux (HF) hemodialysis in 35, and during the first hemodialysis treatment in five patients, as well as in the serum and peritoneal fluid of 13 patients who were receiving continuous ambulatory peritoneal dialysis (CAPD) and in the serum and urine of three patients who had received kidney transplants. Dialysis patients had markedly elevated beta 2M levels; prehemodialysis values were not significantly different for patients receiving conventional v HF hemodialysis. Most of these patients were functionally anephric, and the beta 2M levels did not correlate with age, sex, or time on dialysis. In patients receiving conventional hemodialysis using cellulose acetate membrane, beta 2M levels increased 25.4% after hemodialysis, whereas in patients receiving HF hemodialysis using polysulfone membrane, beta 2M levels decreased significantly (43.0%) after hemodialysis. End-stage renal disease patients dialyzed for the first time had beta 2M values significantly lower than the other two groups because of residual glomerular filtration rate (GFR). CAPD patients also had lower values because they had an estimated loss of 80.4 mg/d of beta 2M in the dialysate fluid. In patients with chronic renal failure, beta 2M levels paralleled the increase in serum creatinine. Patients who received kidney transplants had a dramatic decrease in beta 2M levels that correlated with improvement in GFR. beta 2M correlated with the residual GFR, and its removal was membrane-dependent.(ABSTRACT TRUNCATED AT 250 WORDS)