Clinical application of the Personal Dialysis Capacity (PDC) test: Serial analysis of peritoneal function in CAPD patients

Clinical application of the Personal Dialysis Capacity (PDC) test: Serial analysis of peritoneal function in CAPD patients.BackgroundPeritoneal damage has been reported since the beginning of CAPD therapy.MethodsTo clarify the change of peritoneal function in CAPD patients, we used the Personal Dialysis Capacity (PDC) test in 22 patients with 49 serial studies and 14 patients with single studies. The data were expressed at the condition of 2.5% (2.27g/dl of glucose), four times at 2,000 ml/day.ResultsIn the mass analysis, the urea generation rate, creatinine generation rate, PNA/PCR, and water removal via the peritoneum (PD) were kept at the same level for almost eight years, and then gradually decreased. Urine volume and residual renal creatinine clearance (CCr) became zero at six years. On the other hand, PD CCr increased gradually with the time course of CAPD, and therefore the total CCr remained at the level of 6.0ml/min even after six years. Weekly urea KT/V decreased gradually from almost 2.800 to 2.000. The protein loss remained approximately 7.0g/day for the initial five years, then became 6.0g/day, except in five patients who showed levels above 10.0g/day on the first test of PDC. Weekly urea KT/V was correlated with residual renal CCr (P < 0.005), and significantly correlated with total CCr (weekly urea KT/V = -0.2798 + 0.3720 × total CCr; r = 0.915, P < 0.001). In the serial analysis, when the first and the last tests were compared, the urea generation rate increased significantly (mean ± sd, 2.800 ± 3.204 vs. 3.882 ± 3.382; P < 0.0001); however, water removal via PD (1364 ± 887 vs. 813 ± 609; P = 0.021), total ultrafiltration (1762 ± 841 vs. 1124 ± 843; P = 0.042), and weekly urea KT/V (2.285 ± 0.486 vs. 2.112 ± 0.512; P = 0.026) decreased significantly. The delta water removal via PD/duration became negative (-10.03 ± 6.59 ml/week) in all 7 patients after more than four years, however, it was positive (+14.40 ± 7.84 ml/week) in 6 of 10 patients after less than one year.ConclusionThese results suggest that water removal via PD increases within one year, then decreases after four years. The PDC test is useful to evaluate the change of peritoneal function in mass and serial analyses

IgG subclasses in patients with membranoproliferative glomerulonephritis, membranous nephropathy, and lupus nephritis

IgG subclasses in patients with membranoproliferative glomerulonephritis, membranous nephropathy, and lupus nephritis. Primary glomerulopathy can be classified into seven essential patterns based on histopathological studies. The pathogenesis of membranoproliferative glomerulonephritis (MPGN), and membranous nephropathy (MN), which show glomerular IgG deposition and induce mainely nephrotic syndrome, is not known. To clarify the role of IgG subclass in glomerulonephritis, we compared serum concentrations of IgG subclasses, the ratio of serum IgG subclasses to total IgG (%IgG subclass), and glomerular deposition of IgG subclasses between 7 MPGN patients, 21 MN patients, and 9 lupus nephritis (LN) patients. Serum IgG subclasses and %IgG in all groups were almost within normal range based on the values in Japanese healthy adults. In the MPGN and MN groups, the IgG1 concentration was significant lower than that of the LN group (P < 0.001, P < 0.0001, respectively). The IgG2 concentration in the MPGN group decreased significantly compared with that in the LN group (P < 0.05). The %IgG2 of the LN group decreased significantly compared with that of the MN group (P < 0.05). The %IgG3 of the MPGN group was significantly higher than that of the MN group (P < 0.05). The glomerular immunoflourescent intensity of IgG1 and IgG2 were significantly stronger in the LN group than in the MPGN and MN groups (IgG1, P < 0.001, P < 0.01, respectively; IgG2, P < 0.0001, P < 0.0001, respectively). IgG3 in the MPGN and LN groups deposited significantly compared with that in the MN group (P < 0.0001, P < 0.01, respectively). The intensity of IgG4 in the MN group showed a significant difference compared with that in the MPGN and LN groups (P < 0.0001, P < 0.01, respectively). IgG3 is an important factor in the pathogenesis of primary MPGN, while IgG4 relates to glomerular IgG deposition in MN