Masayuki Azuma

Elevation of Interleukin 6 in the Dialysate Reflects Peritoneal Stimuli and Deterioration of Peritoneal Function

Akira Fujimori, MD, Artificial Kidney Department, Konan Hospital, 1-5-16, Kamokogahara, Higashinada-ku, Kobe 658 (Japan) Dear Sir, Deterioration of peritoneal function, in which inadequate ultrafiltration is usually present, is a serious complication of long-term CAPD patients. At present, however, no simple means to evaluate peritoneal function have been established. Interleukin 6 (IL-6) is secreted in vitro by peritoneal mesothe-lial cells [1], and a very high EL-6 concentration in the CAPD effluent was associated with increased permeability of the peritoneum [2]. Therefore, we measured dialysate IL-6 and discussed the relationship between IL-6 and peritoneal function. Peritoneal function was evaluated by peritoneal function index (PFI), which was the ratio of ultrafiltration volume (ml) to dialysate osmotic pressure (mosm) [3]. As shown in figure 1, a negative correlation between PFI and dialysate IL·6 concentration was observed. Then, we examined the effects of dialysate glucose on effluent IL·6, since high concentrations of the dialysate glucose appear to be one of the causative factors of deterioration of peritoneal function. As shown in figure 2, dialysate glucose dosedependently increased IL·6 concentration. Although it is not known whether IL-6 is secreted by peritoneal mesothelial cells or other cell types such as fibroblasts, T cells, or endothelial cells, IL-6 could be a marker for peritoneal function and possibly histological injuries of the peritoneum. Many of the longterm CAPD patients have problems of inadequate ultrafiltration. They might drop out of the CAPD treatment or would be treated under hemodialysis until peritoneal function recovered. Therefore, measurement of effluent IL-6 might help to decide whether or not CAPD should be interrupted or discontinued. In addition, effluent IL-6 might also indicate the appropriate time to resume CAPD treatment.

Measurement of Cortical Bone Density in the Radius by Peripheral Quantitative Computed Tomography in Hemodialysis Patients

Akira Fujimori, MD, Department of Artificial Kidney, Konan Hospital, 1-5-16 Kamokogahara, Higashinada-ku, Kobe 658 (Japan) Dear Sir, In the uremic patients who develop secondary hyperparathyroidism, bone loss in the cortex would be more remarkable than in the trabecular bone, which may increase in some patients [1]. Since bone mineral density (BMD) of the lumbar spine determined by dual-energy X-ray absorptiometry does not help us evaluate the severity of the renal osteodystrophy, we used peripheral quantitative computed tomography (pQCT), which can separately determine cortical BMD and trabecular BMD of the radius, to examine the clinical importance of the measurement of the cortical BMD in hemodialysis patients. Measurement of BMD was performed as reported before [2], The device used was XCT-960 (Stratec-Norland, Germany and USA). Trabecular BMD was measured at the ultradistal site of the radius (at 4% of the length of the bone from the distal end). A more proximal site at 15% with abundant cortical bone was selected to measure cortical BMD. After a transsectional slice of the radius with 2.5 mm thickness had been obtained, 55% of the total bone area was removed from the periosteal surface, to peel