[What does circulating beta 2 microglobulin signify in uremic patients on maintenance dialysis?].

The authors report a 2 years prospective study on s beta 2M variations observed in a large uremic population (237 patients, 159 M, 78 F, age: 51.1 +/- 5.9 y.o.). The study consisted in two parts. A long term follow-up of s beta 2M in patients regularly treated with various dialysis modalities; hemodialysis (HD), hemofiltration (HF), hemodiafiltration (HDF), intermittent peritoneal dialysis (IPD) and continuous ambulatory peritoneal dialysis (CAPD). s beta 2M was found elevated in the overall population (41.4 +/- 10.2 mg/l) with a 12.5% variation over time observation in stable patients, not influenced by sex, causal nephropathy, and dialysis mode in anuric patients, beta 2M was inversely correlated with residual diuresis. Residual kidney function preserved longer and in a higher proportion of PD patients was the only significant fact explaining for the difference observed in s beta 2M levels between HD (46 +/- 5) and PD (33 +/- 3) patients. Intercurrent inflammatory and tumoral states increased significantly s beta 2M level in uremic patients. The short term study showed that highly permeable membranes (AN69, polysulphone) used either in HD, HF or HDF were able to decrease s beta 2M from 50 to 60%, and to remove 150 to 200 mg per session, while on the opposite HD/cuprophane increased s beta 2M from 10 to 15%. beta 2M dialysate/plasma equilibrium ratio for peritoneal membrane after a 6 hour dwelling time was 0.20, permitting a net removal of 45 +/- 4 mg/24 h.(ABSTRACT TRUNCATED AT 250 WORDS)