Impact on change in serum beta 2 microglobulin by combination therapy of peritoneal dialysis and hemodialysis: a 12-month preliminary observational study

Abstract

Abstract Background In the Japanese guidelines on combination peritoneal dialysis (PD) and hemodialysis (HD) therapy, patients with serum beta 2 microglobulin (β2MG) levels less than 30 mg/L are recommended. And PD patients with β2MG more than 30 mg/L are considered to transfer to the PD + HD combination therapy. However, the resultant changes in serum β2MG levels by the introduction of PD + HD combination therapy and the factors influencing the change have not clearly elucidated. Methods We retrospectively studied 11 PD patients (mean age 56.4 ± 12.9 years, 10 males) with baseline β2MG levels > 30 mg/L with respect to changes in β2MG and its related factors for 12 months after the introduction of combination therapy of PD plus once a week HD (4 h) using a high-performance dialyzer. Laboratory data including hemoglobin, albumin, C-reactive protein, blood urea nitrogen, creatinine, and the patients’ demographic profiles, and HD-related factors, such as Kt/V and blood flow rate, were assessed. Results Serum β2MG levels decreased statistically significantly after the introduction of combination therapy: from 36.7 ± 6.7 mg/L at 0 months, to 33.4 ± 6.1 mg/L at 3 months (p = 0.030, compared to baseline), 32.9 ± 4.5 mg/L at 6 months (p = 0.009), and 33.3 ± 5.3 mg/L at 12 months (p = 0.023), respectively. However, only 27–36% patients achieved target β2MG levels of < 30 mg/L during the observation period. Regarding influencing factors, serum albumin levels, blood flow rates of HD, residual renal function and baseline β2MG were associated with a decrease in serum β2MG levels on univariate analysis. In multivariate analysis, serum albumin at 3 and 12 months correlated significantly with Δβ2MG (β =  − 0.990, p = 0.032 at 3 months, β =  − 0.551, p = 0.033 at 12 months). Urine volume at 12 months correlated significantly with Δβ2MG (β = 0.507, p = 0.019). Conclusions Combination therapy of PD and HD might reduce serum β2MG levels, but with marginal efficacy. Our preliminary data indicate that the combination therapy of PD and once weekly HD is not sufficient to significantly decrease serum β2MG levels. Additional HD prescriptions, such as increase in blood flow rate and hemodiafiltration, need to be tested in order to improve β2MG levels in these patients.